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Near-infrared spectroscopy study of tourniquet-induced forearm ischaemia in patients with coronary artery disease

2013-04-23T15:31:01Z

Abstract: Near-Infrared Spectroscopy (NIR) can be employed to monitor local changes in haemodynamics and oxygenation of human tissues. A preliminary study has been performed in order to evaluate the NIRS transmittance response to induced forearm ischaemia in patients with coronary artery disease (CAD). The population consists in 40 patients with cardiovascular risk factors and angiographically documented CAD, compared to a group of 13 normal subjects. By inflating and subsequently deflating a cuff placed around the patient arm, an ischaemia has been induced and released, and the patients have been observed until recovery of the basal conditions. A custom LAIRS spectrometer (IRIS) has been used to collect the backscattered light intensities from the patient forearm throughout the ischaemic and the recovery phase. The time dependence of the near-infrared transmittance on the control group is consistent with the available literature. On the contrary, the magnitude and dynamics of the NIRS signal on the CAD patients show deviations from the documented normal behavior, which can be tentatively attributed to abnormal vessel stiffness. These preliminary results, while validating the performance of the IRIS spectrometer, are strongly conducive towards the applicability of the NIRS technique to ischaemia analysis and to endothelial dysfunction characterization in CAD patients with cardiovascular risk factors.

Tissue surface as the reference arm in Fourier domain optical coherence tomography

2013-04-26T14:24:11Z

Abstract: We present a simple method applicable to common-path Fourier domain optical coherence tomography (OCT) in which the tissue surface is used as the reference arm. We propose using aluminium hydroxide powder as a potential tissue surface diffuser to allow wider application of this method. This technique allows one to avoid placing a reference arm reflective element, such as glass plate, on tissue, and intrinsically avoids both coherent and complex conjugate mirror artifacts associated with glass plates. Aluminium hydroxide can be sprayed onto tissue using spray nozzles commonly found in endoscopes. The sensitivity of the tissue reference arm common-path OCT image is 94 dB for a 50-mu s charge-coupled device integration time, and 97.5 dB for a 200-mu s CCD integration time. (C) 2012 Society of Photo-Optical Instrumentation Engineers (SPIE). [DOL 10.1117/1.JBO.17.7.071305]

A hybrid organic semiconductor/silicon photodiode for efficient ultraviolet photodetection

2013-04-21T03:07:44Z

Abstract: A method employing conjugated polymer thin film blends is shown to provide a simple and convenient way of greatly enhancing the ultraviolet response of silicon photodetectors. Hybrid organic semiconductor/silicon photodetectors are demonstrated using fluorene copolymers and give a quantum efficiency of 60% at 200 nm. The quantum efficiency is greater than 34% over the entire 200-620 nm range. These devices show promise for use in high sensitivity, low cost UV-visible photodetection and imaging applications. (C) 2007 Optical Society of America

Willin, an upstream component of the Hippo signaling pathway, orchestrates mammalian peripheral nerve fibroblasts

2013-04-10T13:31:04Z

Abstract: Willin/FRMD6 was first identified in the rat sciatic nerve, which is composed of neurons, Schwann cells, and fibroblasts. Willin is an upstream component of the Hippo signaling pathway, which results in the inactivation of the transcriptional coactivator YAP through Ser127 phosphorylation. This in turn suppresses the expression of genes involved in cell growth, proliferation and cancer development ensuring the control of organ size, cell contact inhibition and apoptosis. Here we show that in the mammalian sciatic nerve, Willin is predominantly expressed in fibroblasts and that Willin expression activates the Hippo signaling cascade and induces YAP translocation from the nucleus to the cytoplasm. In addition within these cells, although it inhibits cellular proliferation, Willin expression induces a quicker directional migration towards scratch closure and an increased expression of factors linked to nerve regeneration. These results show that Willin modulates sciatic nerve fibroblast activity indicating that Willin may have a potential role in the regeneration of the peripheral nervous system.

The study of exosomes and microvesicles secreted from breast cancer cell lines

2013-04-04T09:33:32Z

Abstract: Exosomes are small secreted vesicles of endocytic origin with a size range of 50-150 nm. They are secreted by many cell types and display multiple biological functions including immune-activation, immune-suppression, antigen presentation, and the shuttling of mRNA and miRNA, as well as other cargo. We have characterised the exosomes secreted from two breast cancer cell lines, MDA-MB-231 and MCF7. Exosomes secreted from both cell lines display typical markers including ALIX, Tsg101, CD9 and CD63, and were capable of inducing apoptosis of the Jurkat T cell line, indicating the potential immune-suppressive function of such tumour-derived exosomes. To further investigate the biological potential of exosomes, we loaded purified exosomes with gene specific siRNAs using electroporation, and observed the targeted inhibition of both a known component of the exosome pathway, Rab27a, and also the arthritis associated gene ERAP1, demonstrating the potential novel use of exosomes as therapeutic gene delivery vectors. We have also shown that exosomes derived from MDA-MB-231 cells and the parental cells have different lipid composition, as analysed by lipidomics study. Nanoparticle tracking analysis (NTA), which allows the rapid detection of size and concentration of nanoparticles within the size range 10 nm-1000 nm was tested for its ability to accurately measure size and concentration of exosomes and microvesicles under different conditions. NTA was capable of detecting apoptotic vesicles induced by Taxol and Curcumin treatment. Immunodepletion was used to determine the percentage of CD9 and CD63 positive vesicles. Our data suggest that NTA is a useful technique for measuring size and concentration of exosomes and microvesicles. We hypothesized that NTA could assist in the screening of agents that interfere or promote exosome release. NTA was therefore used to detect increases in exosomes secretion induced by Tamoxifen and Thimerosal treatment, and to monitor the inhibition of exosome secretion from MDA-MB-231 breast cancer cells expressing inhibitory RNA targeted for Rab27a, a component of the exosome pathway. Increases in exosome release induced by Tamoxifen and Thimerosal was detected by NTA and a significant reduction in the release of exosomes by inhibition of Rab27a expression was also observed. Treatment with the known exosomal pathway inhibitor DMA also reduced exosome release, establishing the principle of NTA as a screening technique. We further compared the siRNA targeted cells for their ability to migrate, invade and form anchorage-independent colonies, which were all significantly reduced. Supplementation with MDA-MB-231 derived exosomes restored the ability to form colonies, suggesting exosomes may contribute to metastatic lesion formation. These data suggest that the exosomal pathway is a valid target to disrupt the behaviour of tumour cells and NTA can be used to monitor its activity.

Differential timing of gene expression regulation between leptocephali of the two Anguilla eel species in the Sargasso Sea

2013-04-03T09:31:04Z

Abstract: The unique life-history characteristics of North Atlantic catadromous eels have long intrigued evolutionary biologists, especially with respect to mechanisms that could explain their persistence as two ecologically very similar but reproductively and geographically distinct species. Differential developmental schedules during young larval stages have commonly been hypothesized to represent such a key mechanism. We performed a comparative analysis of gene expression by means of microarray experiments with American and European eel leptocephali collected in the Sargasso Sea in order to test the alternative hypotheses of (1) differential timing of gene expression regulation during early development versus (2) species-specific differences in expression of particular genes. Our results provide much stronger support for the former hypothesis since no gene showed consistent significant differences in expression levels between the two species. In contrast, 146 genes showed differential timings of expression between species, although the observed expression level differences between the species were generally small. Consequently, species-specific gene expression regulation seems to play a minor role in species differentiation. Overall, these results show that the basis of the early developmental divergence between the American and European eel is probably influenced by differences in the timing of gene expression regulation for genes involved in a large array of biological functions.

You are what you eat : Within-subject increases in fruit and vegetable consumption confer beneficial skin-color changes

2013-04-21T03:36:10Z

Abstract: Background: Fruit and vegetable consumption and ingestion of carotenoids have been found to be associated with human skin-color (yellowness) in a recent cross-sectional study. This carotenoid-based coloration contributes beneficially to the appearance of health in humans and is held to be a sexually selected cue of condition in other species. Methodology and Principal Findings: Here we investigate the effects of fruit and vegetable consumption on skin-color longitudinally to determine the magnitude and duration of diet change required to change skin-color perceptibly. Diet and skin-color were recorded at baseline and after three and six weeks, in a group of 35 individuals who were without makeup, self-tanning agents and/or recent intensive UV exposure. Six-week changes in fruit and vegetable consumption were significantly correlated with changes in skin redness and yellowness over this period, and diet-linked skin reflectance changes were significantly associated with the spectral absorption of carotenoids and not melanin. We also used psychophysical methods to investigate the minimum color change required to confer perceptibly healthier and more attractive skin-coloration. Modest dietary changes are required to enhance apparent health (2.91 portions per day) and attractiveness (3.30 portions). Conclusions: Increased fruit and vegetable consumption confers measurable and perceptibly beneficial effects on Caucasian skin appearance within six weeks. This effect could potentially be used as a motivational tool in dietary intervention. Description: R Whitehead was funded by an ESRC Studentship.

The opportunity costs of aid

2013-03-20T21:31:01Z

Description: Responce to Helena Watson, Aid, aid everywhere but still not a drop in the sink. BMJ 2009; 338: a3136

"Adaptive response" - some underlying mechanisms and open questions

2013-01-10T12:01:02Z

Abstract: Organisms are affected by different DNA damaging agents naturally present in the environment or released as a result of human activity. Many defense mechanisms have evolved in organisms to minimize genotoxic damage. One of them is induced radioresistance or adaptive response. The adaptive response could be considered as a nonspecific phenomenon in which exposure to minimal stress could result in increased resistance to higher levels of the same or to other types of stress some hours later. A better understanding of the molecular mechanism underlying the adaptive response may lead to an improvement of cancer treatment, risk assessment and risk management strategies, radiation protection, e. g. of astronauts during long-term space flights. In this mini-review we discuss some open questions and the probable underlying mechanisms involved in adaptive response: the transcription of many genes and the activation of numerous signaling pathways that trigger cell defenses - DNA repair systems, induction of proteins synthesis, enhanced detoxification of free radicals and antioxidant production.

Aberrant NF-kappaB expression in autism spectrum condition : a mechanism for neuroinflammation

2013-04-21T03:07:37Z

Abstract: Autism spectrum condition (ASC) is recognized as having an inflammatory component. Post-mortem brain samples from patients with ASC display neuroglial activation and inflammatory markers in cerebrospinal fluid, although little is known about the underlying molecular mechanisms. Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) is a protein found in almost all cell types and mediates regulation of immune response by inducing the expression of inflammatory cytokines and chemokines, establishing a feedback mechanism that can produce chronic or excessive inflammation. This article describes immunodetection and immunofluorescence measurements of NF-κB in human post-mortem samples of orbitofrontal cortex tissue donated to two independent centers: London Brain Bank, Kings College London, UK (ASC: n = 3, controls: n = 4) and Autism Tissue Program, Harvard Brain Bank, USA (ASC: n = 6, controls: n = 5). The hypothesis was that concentrations of NF-κB would be elevated, especially in activated microglia in ASC, and pH would be concomitantly reduced (i.e., acidification). Neurons, astrocytes, and microglia all demonstrated increased extranuclear and nuclear translocated NF-κB p65 expression in brain tissue from ASC donors relative to samples from matched controls. These between-groups differences were increased in astrocytes and microglia relative to neurons, but particularly pronounced for highly mature microglia. Measurement of pH in homogenized samples demonstrated a 0.98-unit difference in means and a strong (F = 98.3; p = 0.00018) linear relationship to the expression of nuclear translocated NF-κB in mature microglia. Acridine orange staining localized pH reductions to lysosomal compartments. In summary, NF-κB is aberrantly expressed in orbitofrontal cortex in patients with ASC, as part of a putative molecular cascade leading to inflammation, especially of resident immune cells in brain regions associated with the behavioral and clinical symptoms of ASC.

Fluorescence suppression using wavelength modulated Raman spectroscopy in fiber-probe-based tissue analysis

2012-12-14T16:31:02Z

Abstract: In the field of biomedical optics, Raman spectroscopy is a powerful tool for probing the chemical composition of biological samples. In particular, fiber Raman probes play a crucial role for in vivo and ex vivo tissue analysis. However, the high-fluorescence background typically contributed by the auto fluorescence from both a tissue sample and the fiber-probe interferes strongly with the relatively weak Raman signal. Here we demonstrate the implementation of wavelength-modulated Raman spectroscopy (WMRS) to suppress the fluorescence background while analyzing tissues using fiber Raman probes. We have observed a significant signal-to-noise ratio enhancement in the Raman bands of bone tissue, which have a relatively high fluorescence background. Implementation of WMRS in fiber-probe-based bone tissue study yielded usable Raman spectra in a relatively short acquisition time (∼30 s), notably without any special sample preparation stage. Finally, we have validated its capability to suppress fluorescence on other tissue samples such as adipose tissue derived from four different species.

Routine use of microbial whole genome sequencing in diagnostic and public health microbiology

2012-12-14T10:31:01Z

Abstract: Whole genome sequencing (WGS) promises to be transformative for the practice of clinical microbiology, and the rapidly falling cost and turnaround time mean that this will become a viable technology in diagnostic and reference laboratories in the near future. The objective of this article is to consider at a very practical level where, in the context of a modern diagnostic microbiology laboratory, WGS might be cost-effective compared to current alternatives. We propose that molecular epidemiology performed for surveillance and outbreak investigation and genotypic antimicrobial susceptibility testing for microbes that are difficult to grow represent the most immediate areas for application of WGS, and discuss the technical and infrastructure requirements for this to be implemented.

The dyslexia candidate locus on 2p12 is associated with general cognitive ability and white matter structure

2012-12-13T10:01:11Z

Abstract: Independent studies have shown that candidate genes for dyslexia and specific language impairment (SLI) impact upon reading/language-specific traits in the general population. To further explore the effect of disorder-associated genes on cognitive functions, we investigated whether they play a role in broader cognitive traits. We tested a panel of dyslexia and SLI genetic risk factors for association with two measures of general cognitive abilities, or IQ, (verbal and non-verbal) in the Avon Longitudinal Study of Parents and Children (ALSPAC) cohort (N>5,000). Only the MRPL19/C2ORF3 locus showed statistically significant association (minimum P = 0.00009) which was further supported by independent replications following analysis in four other cohorts. In addition, a fifth independent sample showed association between the MRPL19/C2ORF3 locus and white matter structure in the posterior part of the corpus callosum and cingulum, connecting large parts of the cortex in the parietal, occipital and temporal lobes. These findings suggest that this locus, originally identified as being associated with dyslexia, is likely to harbour genetic variants associated with general cognitive abilities by influencing white matter structure in localised neuronal regions.

Towards a guideline for person-centered research in clinical communication : lessons learned from three countries

2012-12-12T13:28:34Z

Abstract: The delivery of quality health care is dependent to a large degree on the success of the interaction between health care provider and patient. The ability to research this interaction has improved with the development of recording technology, storage and data coding. In addition, familiarity with recording of doctor-patient communication has increased encouraging researchers to embark on developing this data-rich resource. Factors that are pertinent to the collection of this material are outlined from the experience of researchers from three countries: The Netherlands, Norway and the UK. The conclusion stresses the need to attend closely to the issues listed to increase the likelihood of obtaining a research platform for investigating health care encounters in some depth. The article presents a first step in the production of a practical, person-centered guideline for this important research endeavour.

Stiffness: a key mechanical factor in normal, degenerate and artificial lumbar intervertebral discs

2012-10-23T13:46:52Z

Abstract: This thesis describes the development of artificial disc technology for the replacement of intervertebral discs in the human lumbar spine. The clinical problem is back pain. There may be a relationship between certain forms of back pain and disc degeneration. The mechanical properties of human intervertebral discs are examined in detail. The genetic basis of disc degeneration is presented. The hypothesis is that such degeneration leads to a loss of normal stiffness in the segments affected leading to abnormal mechanical behaviour which in turn leads to pain. The evidence for this is presented. The development of surgical solutions to relieve back pain, from fusion through first generation mechanical artificial discs to elastomeric designs, is traced. The author‘s personal contributions to this area of knowledge are set out. The appreciation of the requirement for a restoration of physiological stiffness is argued throughout, showing where fusion and first generation discs have not met the clinical aim of pain relief, because they have not restored physiological stiffness. The path to an elastomeric, viscoelastic, polyhydrocarbon, rubber solution in the form of the “Freedom“ disc has filled 17 years of the author‘s academic pursuits. It will be shown that this technology may represent a possible solution to the clinical problem. Failure is part of all new advancement and this too is presented, to show how that has influenced thinking, producing original ideas to overcome these failures. Providing lessons are learned from these failures then our patients in the future will benefit.

The role of ChlR1 in DNA replication, DNA damage repair and cohesion establishment

2012-09-22T19:39:44Z

Abstract: Sister chromatid cohesion is essential for the equal distribution of genetic material in mitosis. The cohesin complex plays a central role in the establishment of sister chromatid cohesion. The cohesin complex is a ring shaped structure that encircles sister chromatids prior to the onset of anaphase ensuring equal distribution of genetic material. The DEAD/H DNA helicase ChlR1 is important in the establishment of sister chromatid cohesion. ChlR1 interacts with the cohesin complex and is required for the loading of cohesin onto DNA. Cohesin is loaded onto the DNA during DNA replication. Here I identified a novel interacting partner of ChlR1. The multifunctional DNA binding protein FHL2 was shown to interact with ChlR1 and FHL2 was shown to have a role in sister chromatid cohesion since depletion of FHL2 resulted in abnormal metaphase spreads and reduced centromeric cohesion. These sister chromatid cohesion defects also result in a G₂/M delay. Here I show an additional function of ChlR1 in the repair of DNA damage. ChlR1 was required for the repair of DNA double strand breaks and ChlR1 was recruited to DNA double strand breaks. Furthermore the function of ChlR1 in DNA double strand break repair is S phase specific. This suggests that ChlR1 is important in the homology recombination repair pathway. I also show that ChlR1 is important in DNA replication. Depletion of ChlR1 results in inefficient DNA replication. In addition depletion of ChlR1 results in defects in DNA replication after hydroxyurea treatment. The results in this thesis shed light on novel functions of the DNA helicase ChlR1 in DNA replication and DNA damage repair and the multifunctional DNA binding protein FHL2 in cohesion establishment.

TOX3 : a candidate breast cancer predisposition gene

2012-10-25T08:48:14Z

Cost-effectiveness of internal limiting membrane peeling versus no peeling for patients with an idiopathic full-thickness macular hole : results from a randomised controlled trial

2013-04-21T04:04:18Z

Abstract: Aim To determine whether internal limiting membrane (ILM) peeling is cost-effective compared with no peeling for patients with an idiopathic stage 2 or 3 full-thickness macular hole. Methods A cost-effectiveness analysis was performed alongside a randomised controlled trial. 141 participants were randomly allocated to receive macular-hole surgery, with either ILM peeling or no peeling. Health-service resource use, costs and quality of life were calculated for each participant. The incremental cost per quality-adjusted life year (QALY) gained was calculated at 6 months. Results At 6 months, the total costs were on average higher (424 pound, 95% CI -182 to 1045) in the No Peel arm, primarily owing to the higher reoperation rate in the No Peel arm. The mean additional QALYs from ILM peel at 6 months were 0.002 (95% CI 0.01 to 0.013), adjusting for baseline EQ-5D and other minimisation factors. A mean incremental cost per QALY was not computed, as Peeling was on average less costly and slightly more effective. A stochastic analysis suggested that there was more than a 90% probability that Peeling would be cost-effective at a willingness-to-pay threshold of 20 pound 000 per QALY. Conclusion Although there is no evidence of a statistically significant difference in either costs or QALYs between macular hole surgery with or without ILM peeling, the balance of probabilities is that ILM Peeling is likely to be a cost-effective option for the treatment of macular holes. Further long-term follow-up data are needed to confirm these findings.

Exploiting multimode waveguides for pure fibre-based imaging

2013-04-21T04:06:54Z

Abstract: There has been an immense drive in modern microscopy towards miniaturisation and ﬁbre based technology. This has been necessitated by the need to access hostile or diffcult environments in-situ and in-vivo. Strategies to date have included the use of specialist ﬁbres and miniaturised scanning systems accompanied by ingenious microfabricated lenses. We present a novel approach for this ﬁeld by utilising disordered light within a standard multimode optical ﬁbre for lensless microscopy and optical mode conversion. We demonstrate the modalities of bright-ﬁeld and dark-ﬁeld imaging and scanning ﬂuorescence microscopy at acquisition rates allowing observation of dynamic processes such as Brownian motion of mesoscopic particles. Furthermore, we show how such control can realise a new form of mode converter and generate various types of advanced light ﬁelds such as propagation-invariant beams and optical vortices. These may be useful for future ﬁbre based implementations of super-resolution or light sheet microscopy.

News from the international study Control of Adolescent Smoking : Parental influences on smoking among Scottish adolescents

2012-12-12T10:20:08Z

News from the international study Control of Adolescent Smoking : Smoking, school achievement and educational aspirations among Scottish adolescents

2012-12-12T10:20:08Z

News from the internation study Control of Adolescent Smoking. : Smoking and other health-related behaviours and health indicators in Scottish adolescents

2012-12-12T10:20:07Z

News from the international study Control of Adolescent Smoking : Smoking in Scottish schools

2012-12-12T10:20:06Z

TGFbeta induces apoptosis and EMT in primary mouse hepatocytes independently of p53, p21(Cip1) or Rb status

2013-04-21T04:05:06Z

Abstract: Background: TGF beta has pleiotropic effects that range from regulation of proliferation and apoptosis to morphological changes and epithelial-mesenchymal transition (EMT). Some evidence suggests that these effects may be interconnected. We have recently reported that P53, P21(Cip1) and pRB, three critical regulators of the G1/S transition are variably involved in TGF beta-induced cell cycle arrest in hepatocytes. As these proteins are also involved in the regulation of apoptosis in many circumstances, we investigated their contribution to other relevant TGF beta-induced effects, namely apoptosis and EMT, and examined how the various processes were interrelated. Methods: Primary mouse hepatocytes deficient in p53, p21 and/or Rb, singly or in combination were treated with TGF beta for 24 to 96 hours. Apoptosis was quantified according to morphology and by immunostaining for cleavedcapsase 3. Epithelial and mesenchymal marker expression was studied using immunocytochemistry and real time PCR. Results: We found that TGF beta similarly induced morphological changes regardless of genotype and independently of proliferation index or sensitivity to inhibition of proliferation by TGF beta. Morphological changes were accompanied by decrease in E-cadherin and increased Snail expression but the mesenchymal markers (N-cadherin, SMA alpha and Vimentin) studied remained unchanged. TGF beta induced high levels of apoptosis in p53-/-, Rb-/-, p21(cip1)-/- and control hepatocytes although with slight differences in kinetics. This was unrelated to proliferation or changes in morphology and loss of cell-cell adhesion. However, hepatocytes deficient in both p53 and p21(cip1)were less sensitive to TGF beta-induced apoptosis. Conclusion: Although p53, p21(Cip1) and pRb are well known regulators of both proliferation and apoptosis in response to a multitude of stresses, we conclude that they are critical for TGF beta-driven inhibition of hepatocytes proliferation, but only slightly modulate TGF beta-induced apoptosis. This effect may depend on other parameters such as proliferation and the presence of other regulatory proteins as suggested by the consequences of p53, p21(Cip1) double deficiency. Similarly, p53, p21(Cip1) and pRB deficiency had no effect on the morphological changes and loss of cell adhesion which is thought to be critical for metastasis. This indicates that possible association of these genes with metastasis potential would be unlikely to involve TGF beta-induced EMT.

Assessing asthma control in UK primary care : Use of routinely collected prospective observational consultation data to determine appropriateness of a variety of control assessment models

2013-04-21T04:04:29Z

Abstract: Background: Assessing asthma control using standardised questionnaires is recommended as good clinical practice but there is little evidence validating their use within primary care. There is however, strong empirical evidence to indicate that age, weight, gender, smoking, symptom pattern, medication use, health service resource use, geographical location, deprivation, and organisational issues, are factors strongly associated with asthma control. A good control measure is therefore one whose variation is most explained by these factors. Method: Eight binary (Yes = poor control, No = good control) models of asthma control were constructed from a large UK primary care dataset: the Royal College of Physicians 3-Questions (RCP-3Qs); the Jones Morbidity Index; three composite measures; three single component models. Accounting for practice clustering of patients, we investigated the effects of each model for assessing control. The binary models were assessed for goodness-of-fit statistics using Pseudo R-squared and Akaikes Information Criteria (AIC), and for performance using Area Under the Receiver Operator Characteristic (AUROC). In addition, an expanded RCP-3Q control scale (0-9) was derived and assessed with linear modelling. The analysis identified which model was best explained by the independent variables and thus could be considered a good model of control assessment. Results: 1,205 practices provided information on 64,929 patients aged 13+ years. The RCP-3Q model provided the best fit statistically, with a Pseudo R-squared of 18%, and an AUROC of 0.79. By contrast, the composite model based on the GINA definition of controlled asthma had a higher AIC, an AUROC of 0.72, and only 10% variability explained. In addition, although the Peak Expiratory Flow Rate (PEFR) model had the lowest AIC, it had an AUROC of 71% and only 6% of variability explained. However, compared with the RCP-3Qs binary model, the linear RCP-3Q Total Score Model (Scale 0-9), was found to be a more robust 'tool' for assessing asthma control with a lower AIC (28,6163) and an R-squared of 33%. Conclusion: In the absence of a gold standard for assessing asthma control in primary care, the results indicate that the RCP-3Qs is an effective control assessment tool but, for maximum effect, the expanded scoring model should be used.

Modulated Raman spectroscopy for enhanced identification of bladder tumor cells in urine samples

2013-04-21T03:08:16Z

Abstract: Standard Raman spectroscopy (SRS) is a noninvasive technique that is used in the biomedical field to discriminate between normal and cancer cells. However, the presence of a strong fluorescence background detracts from the use of SRS in real-time clinical applications. Recently, we have reported a novel modulated Raman spectroscopy (MRS) technique to extract the Raman spectra from the background. In this paper, we present the first application of MRS to the identification of human urothelial cells (SV-HUC-1) and bladder cancer cells (MGH) in urine samples. These results are compared to those obtained by SRS. Classification using the principal component analysis clearly shows thatMRS allows discrimination between Raman spectra of SV-HUC-1 andMGH cells with high sensitivity (98%) and specificity (95%). MRS is also used to distinguish between SV-HUC-1 and MGH cells after exposure to urine for up to 6 h.We observe a marked change in the MRS of SV-HUC-1 and MGH cells with time in urine, indicating that the conditions of sample collection will be important for the application of this methodology to clinical urine samples.

Systematic review of the agreement of tonometers with Goldmann applanation tonometry

2013-04-21T04:05:35Z

Abstract: OBJECTIVE: To assess the agreement of tonometers available for clinical practice with the Goldmann applanation tonometer (GAT), the most commonly accepted reference device. DESIGN: A systematic review and meta-analysis of directly comparative studies assessing the agreement of 1 or more tonometers with the reference tonometer (GAT). PARTICIPANTS: A total of 11 582 participants (15 525 eyes) were included. METHODS: Summary 95% limits of agreement (LoA) were produced for each comparison. MAIN OUTCOME MEASURES: Agreement, recordability, and reliability. RESULTS: A total of 102 studies, including 130 paired comparisons, were included, representing 8 tonometers: dynamic contour tonometer, noncontact tonometer (NCT), ocular response analyzer, Ocuton S, handheld applanation tonometer (HAT), rebound tonometer, transpalpebral tonometer, and Tono-Pen. The agreement (95% limits) seemed to vary across tonometers: 0.2 mmHg (-3.8 to 4.3 mmHg) for the NCT to 2.7 mmHg (-4.1 to 9.6 mmHg) for the Ocuton S. The estimated proportion within 2 mmHg of the GAT ranged from 33% (Ocuton S) to 66% and 59% (NCT and HAT, respectively). Substantial inter- and intraobserver variability were observed for all tonometers. CONCLUSIONS: The NCT and HAT seem to achieve a measurement closest to the GAT. However, there was substantial variability in measurements both within and between studies. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Regional susceptibility to TNF-alpha induction of murine brain inflammation via classical IKK/NF-kappa B signalling

2013-04-21T04:05:40Z

Abstract: It is becoming clear that inflammation plays a significant role in a number of neurological and psychiatric conditions. Post mortem brain samples in Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis, multiple sclerosis, schizophrenia and most recently autism spectrum condition, all exhibit neuroglial activation and inflammatory markers within the CSF. Many questions remain about the underlying molecular mechanisms. By adding the pro-inflammatory cytokine, TNF-alpha, to mouse brain tissue we demonstrated that the frontal lobes and temporal region, areas involved in higher functions such as memory and learning, are most susceptible to cytokine-induced inflammation via the NF-kappa B signalling pathway. We observed direct correlations between the volumetric increase and molecular expression indicating that therapeutic targets in these lobes may require different approaches when treating conditions with a central neuroinflammatory component.

Surveillance for ocular hypertension : an evidence synthesis and economic evaluation

2013-04-21T04:05:29Z

Abstract: OBJECTIVES: To determine effective and efficient monitoring criteria for ocular hypertension [raised intraocular pressure (IOP)] through (i) identification and validation of glaucoma risk prediction models; and (ii) development of models to determine optimal surveillance pathways. DESIGN: A discrete event simulation economic modelling evaluation. Data from systematic reviews of risk prediction models and agreement between tonometers, secondary analyses of existing datasets (to validate identified risk models and determine optimal monitoring criteria) and public preferences were used to structure and populate the economic model. SETTING: Primary and secondary care. PARTICIPANTS: Adults with ocular hypertension (IOP > 21mmHg) and the public (surveillance preferences). INTERVENTIONS: We compared five pathways: two based on National Institute for Health and Clinical Excellence (NICE) guidelines with monitoring interval and treatment depending on initial risk stratification, 'NICE intensive' (4-monthly to annual monitoring) and 'NICE conservative' (6-monthly to biennial monitoring); two pathways, differing in location (hospital and community), with monitoring biennially and treatment initiated for a >/= 6% 5-year glaucoma risk; and a 'treat all' pathway involving treatment with a prostaglandin analogue if IOP > 21 mmHg and IOP measured annually in the community. MAIN OUTCOME MEASURES: Glaucoma cases detected; tonometer agreement; public preferences; costs; willingness to pay and quality-adjusted life-years (QALYs). RESULTS: The best available glaucoma risk prediction model estimated the 5-year risk based on age and ocular predictors (IOP, central corneal thickness, optic nerve damage and index of visual field status). Taking the average of two IOP readings, by tonometry, true change was detected at two years. Sizeable measurement variability was noted between tonometers. There was a general public preference for monitoring; good communication and understanding of the process predicted service value. 'Treat all' was the least costly and 'NICE intensive' the most costly pathway. Biennial monitoring reduced the number of cases of glaucoma conversion compared with a 'treat all' pathway and provided more QALYs, but the incremental cost-effectiveness ratio (ICER) was considerably more than pound30,000. The 'NICE intensive' pathway also avoided glaucoma conversion, but NICE-based pathways were either dominated (more costly and less effective) by biennial hospital monitoring or had a ICERs > pound30,000. Results were not sensitive to the risk threshold for initiating surveillance but were sensitive to the risk threshold for initiating treatment, NHS costs and treatment adherence. LIMITATIONS: Optimal monitoring intervals were based on IOP data. There were insufficient data to determine the optimal frequency of measurement of the visual field or optic nerve head for identification of glaucoma. The economic modelling took a 20-year time horizon which may be insufficient to capture long-term benefits. Sensitivity analyses may not fully capture the uncertainty surrounding parameter estimates. CONCLUSIONS: For confirmed ocular hypertension, findings suggest that there is no clear benefit from intensive monitoring. Consideration of the patient experience is important. A cohort study is recommended to provide data to refine the glaucoma risk prediction model, determine the optimum type and frequency of serial glaucoma tests and estimate costs and patient preferences for monitoring and treatment. FUNDING: The National Institute for Health Research Health Technology Assessment Programme.

A framework for the evaluation of new interventional procedures

2013-04-21T04:04:17Z

Abstract: Objectives: The introduction of new interventional procedures is less regulated than for other health technologies such as pharmaceuticals. Decisions are often taken on evidence of efficacy and short-term safety from small-scale usually observational studies. This reflects the particular challenges of evaluating interventional procedures – the extra facets of skill and training and the difficulty defining a 'new‘ technology. Currently, there is no framework to evaluate new interventional procedures before they become available in clinical practice as opposed to new pharmaceuticals. This paper proposes a framework to guide the evaluation of a new interventional procedure. Proposed framework: A framework was developed consisting of a four-stage progressive evaluation for a new interventional procedure: Stage 1: Development; Stage 2: Efficacy and short-term safety; Stage 3: Effectiveness and cost-effectiveness; and Stage 4: Implementation. The framework also suggests the types of studies or data collection methods that can be used to satisfy each stage. Conclusions: This paper makes a first step on a framework for generating evidence on new interventional procedures. The difficulties and limitations of applying such a framework are discussed.

Screening tests for detecting open-angle glaucoma : systematic review and meta-analysis

2013-04-21T03:33:34Z

Abstract: PURPOSE. To assess the comparative accuracy of potential screening tests for open angle glaucoma (OAG). METHODS. Medline, Embase, Biosis (to November 2005), Science Citation Index (to December 2005), and The Cochrane Library (Issue 4, 2005) were searched. Studies assessing candidate screening tests for detecting OAG in persons older than 40 years that reported true and false positives and negatives were included. Meta-analysis was undertaken using the hierarchical summary receiver operating characteristic model. RESULTS. Forty studies enrolling over 48,000 people reported nine tests. Most tests were reported by only a few studies. Frequency-doubling technology (FDT; C-20-1) was significantly more sensitive than ophthalmoscopy (30, 95% credible interval [CrI] 0-62) and Goldmann applanation tonometry (GAT; 45, 95% CrI 17-68), whereas threshold standard automated perimetry (SAP) and Heidelberg Retinal Tomograph (HRT II) were both more sensitive than GAT (41, 95% CrI 14-64 and 39, 95% CrI 3-64, respectively). GAT was more specific than both FDT C-20-5 (19, 95% CrI 0-53) and threshold SAP (14, 95% CrI 1-37). Judging performance by diagnostic odds ratio, FDT, oculokinetic perimetry, and HRT II are promising tests. Ophthalmoscopy, SAP, retinal photography, and GAT had relatively poor performance as single tests. These findings are based on heterogeneous data of limited quality and as such are associated with considerable uncertainty. CONCLUSIONS. No test or group of tests was clearly superior for glaucoma screening. Further research is needed to evaluate the comparative accuracy of the most promising tests. (Invest Ophthalmol Vis Sci. 2008;49:5373-5385) DOI: 10.1167/iovs.07-1501

Internal limiting membrane peeling versus no peeling for idiopathic full-thickness macular hole : a pragmatic randomized controlled trial

2013-04-21T03:33:37Z

Abstract: PURPOSE. To determine whether internal limiting membrane (ILM) peeling is effective and cost effective compared with no peeling in patients with idiopathic stage 2 or 3 full-thickness maculay hole (FTMH). METHODS. This was a pragmatic multicenter randomized controlled trial. Eligible participants front nine centers were randomized to ILM peeling or no peeling (1:1 ratio) in addition to phacovitrectomy, including detachment and removal of the posterior hyaloid and gas tamponade. The primary outcome was distance visual acuity (VA) at 6 months after surgery. Secondary outcomes included hole closure, distance VA at other time points, near VA, contrast sensitivity, reading speed, reoperations, complications, resource use, and participant-reported health status, visual function, and costs. RESULTS. Of 141 participants randomized in nine centers, 127 (90%) completed the 6-month follow-up. Nonstatistically significant differences in distance visual acuity at 6 months were found between groups (Mean difference, 4.8; 95% confidence interval [CI], -0.3 to 9.8; P = 0.063). There was a significantly higher rate of hole closure in the ILM-peel group (56 [84%] vs. 31 [48%]) at 1 month (odds ratio [OR], 6.23; 95% CI, 2.64-14.73; P < 0.001) with fewer reoperations (8 [12%] vs. 31 [48%]) performed by 6 months (OR, 0.14; 95% CI, 0.05-0.34; P < 0.001). Peeling the ILM is likely to be cost effective. CONCLUSION. There was no evidence of a difference in distance VA after the ILM peeling and no-ILM peeling techniques. An important benefit in favor of no ILM peeling was ruled out. Given the higher anatomic closure and lower reoperation rates in the ILM-peel group, ILM peeling seems to be the treatment of choice for idiopathic stage 2 to 3 FTMH. (Clinical Trials.gov number, NCT00286507.) (Invest Ophthalmol Vis Sci 201152: 1586-1592) DOI:10.1167/iovs.10-6287

Dissection of genetic associations with language-related traits in population-based cohorts

2013-04-21T03:08:15Z

Abstract: Recent advances in the field of language-related disorders have led to the identification of candidate genes for specific language impairment (SLI) and dyslexia. Replication studies have been conducted in independent samples including population-based cohorts, which can be characterised for a large number of relevant cognitive measures. The availability of a wide range of phenotypes allows us to not only identify the most suitable traits for replication of genetic association but also to refine the associated cognitive trait. In addition, it is possible to test for pleiotropic effects across multiple phenotypes which could explain the extensive comorbidity observed across SLI, dyslexia and other neurodevelopmental disorders. The availability of genome-wide genotype data for such cohorts will facilitate this kind of analysis but important issues, such as multiple test corrections, have to be taken into account considering that small effect sizes are expected to underlie such associations. Description: The author was supported by the Wellcome Trust [076566/Z/05/Z]; [075491/Z/04] and the Medical Research Council [G0800523/86473].

William Pulteney Alison : activist philanthropist and pioneer of social medicine

2012-06-20T09:13:11Z

Abstract: The thesis looks in detail at three inter-related aspects of Alison's life. It examines, firstly, his role in the development of Edinburgh's rudimentary 'health' network, achieved through the expansion of the existing medical charity structure and the introduction of a more interventionist and coordinated approach to the city's health problems. It traces, secondly, the development of Alison's social thought - in 1820 he believed that medical and practical relief for the poor could and should be supplied through the voluntary charities and only when that proved unsatisfactory through the poor law, whereas by 1840 he argued that public health should be the responsibility of government and that the excessive increase in poverty and disease in Scotland, which he believed had occurred, was proof that the charitable and legal relief provided was inadequate. Finally, Alison's influence on the passage of Scottish poor law and public health legislation in the 1840s and 1850s is examined - the latter involving an assessment of how far he was responsible for the legislative delay. The poor law debate, 1840-1845, which reveals the forces shaping the reform and the prevailing attitudes to poverty, highlights the challenge which Alison's opinions represented and the resulting turmoil in Scottish social thinking, while his reasons for opposing health legislation, which established London control are of great importance. They reveal differences in the rationale behind, and way in which, the concept of public health was developed in Scotland and England. Unlike Chadwick and his supporters, Alison emphasised poverty amelioration and sanitary reform. Part of the explanation for the differing opinions lay in their respective miasmatic and contagionist theories for fever generation, but it also reflects, perhaps more significantly, the impact of European medical police ideas on Scottish medical opinion - Alison's view of public health closely resembled that of the French hygienists.

Quality of care for people with mental handicap and challenging behaviour : an investigation of the impact of staff training in goal attainment scaling and behavioural procedures

2012-06-19T11:30:13Z

Abstract: This study examined the contribution to quality of care of a goal planning technique called Goal Attainment Scaling and its impact upon the quality of life of people with severe mental handicaps and challenging behaviour. The study also seeks to establish the utility of employing Goal Attainment Scaling as a means of evaluating clinical nursing performance, This study essentially aims to bring about changes in the care practices of nurses using a comprehensive staff management procedure. The study was designed as a four phase intervention using a multiple baseline design across three wards in a hospital for people with mental handicaps. Staff on three wards (n = 41) were initially trained over three phases in the use of Goal Attainment Scaling and other procedures. Training was carried out by a combination of workshops and individual tuition which incorporated the use of individualised learning contracts for staff. The fourth phase consisted of establishing weekly meetings to set objectives for staff to achieve that were specifically related to material covered in training. If targets were achieved, staff performance was followed by letters of recognition from managers and by financial donations to ward funds. Dependent measures included frequency of challenging behaviour, quality of staff-resident interaction and engagement, ward activity, residents' adaptive behaviour, staff attitudes and goals set by staff. Results indicate that adaptive behaviour increased by small but statistically significant levels. Levels of challenging display a mixed pattern of results, as do levels of ward activity and quality of interaction, although encouraging trends may be identified. Despite some increases, residents still spend significant amounts of time unoccupied. The number of goals set increased throughout the study, particularly in phase four, data for staff attitudes were not used because of the low compliance rate and changes indicated below. Considerable problems were encountered with turnover of staff and other organisational changes outwith the researcher's control which compromised both the quality of training given to staff and, by virtue of this, the final results. Statistically significant relationships were found to exist between staff turnover and interaction. The implications of this study are discussed and recommendations made for future research.

Health professionals and ethnic Pakistanis in Britain : risk, thalassaemia and audit culture

2012-06-19T10:13:22Z

Abstract: The central theme or 'red-thread' that I consider in this thesis is the concept of risk as it is perceived by and affects the two sides of the medical encounter -in this instance ethnic Pakistanis and Health Professionals- in Britain. Each side very often perceives risk quite distinctively, relating to the balance between the spiritual and temporal realms. This is particularly germane in matters to do with possible congenital defects within the prenatal realm for the ethnic Pakistani, and predominantly Muslim, side of this encounter. Thus one of the factors considered in this thesis is how senses of Islam impact upon the two sides. By ethnic Pakistanis Islam is seen as central to all life decisions, whilst Health Professionals view Islam with some considerable trepidation, little understanding it or its centrality to the former's decision-making processes. This is particularly significant with regard to attitudes to health and health care. In the initial stages of the project I had thought first cousin marriage (FCM), seen by ethnic Pakistanis as desirable and by Health Professionals as putting ethnic Pakistanis at-risk to be central to the argument, but concluded that concerns around FCM were a 'red herring', merely a trope for the tensions between the two sides -at once both British and at-risk from audit culture. Although no longer central, FCM remains a viable touchstone in consideration of the two sides' perceptions of genetic risk. In this thesis the medical encounter between ethnic Pakistanis and Health Professionals is performed within the realm of the so called New Genetics. Here the respective understandings of the New Genetics are informed by the enculturation processes that shape the two sides' world view. Furthermore, I will agree with Lord Robert Winston's and others' concern that any attempt to eradicate an adaptive genetic mutation, in this instance, thalassaemia, from the gene pool is not only undesirable in the short term, but also that such eradications may have an adverse, and far reaching, effect on whole population groups in the future. The main thrust of my argument is that audit culture not only compounds risk for both sides, but also perpetuates institutional racism within the National Health Service (NHS), by promulgating what I have called the language myth. That is to say that much institutional racism is the unwanted by-product of the NHS's attempts to become more patient centred and its continuing efforts to develop systems of best practice. This professionalisation process within the NHS can be seen to impact most strongly in relation to communication -particularly the claimed language barrier between the two sides. This 'barrier' has worrying policy implications for any meaningful communication between the two sides, notably relating to obtaining informed consent from ethnic Pakistani patients -with a resultant increase in risk for the two sides and clear economic consequences for the NHS.

Coping with asthma : investigation and intervention using the self-regulation model

2012-07-24T15:29:30Z

Abstract: The Self-Regulation Model (Leventhal, Nerenz & Steele, 1984) highlights the roles of patients' illness representations, coping, emotional reactions and appraisal of coping in the progression of chronic disease. This thesis incorporates previous literature on adherence, panic-fear and selfmanagement interventions into the model in order to (a) investigate coping with asthma and (b) develop an intervention aimed at improving asthmatic control. New measures of asthmatic control and illness representations of the consequences of having asthma were developed in order to operationalise the model. A cross-sectional study investigated factors influencing asthmatic control in a sample of 35 adult asthma sufferers recruited through a single general practice. Coping was poor, adherence being low and less than 50% of participants reporting current Peak Flow monitoring or medical contact during the previous 12 months. Good coping appeared to be a response to poor asthmatic control, rather than prophylactic. Good asthmatic control was associated with low perceived consequences, recent medical contact, moderate panic-fear and low general avoidance coping. These results imply that asthmatic control may be improved by encouraging sufferers to maintain regular contact with outpatient services and to implement prophylactic coping. Since epidemiological and clinical evidence suggested asthmatic control to be poor in young adults, an intervention was developed to improve asthmatic control in this group by modifying illness representations, coping and panic-fear. The intervention was evaluated in a randomised controlled study of 50 student asthma sufferers identified initially through an epidemiological screening of 2,979 students. It led to increased Preventer medication use and Peak Flow monitoring and decreased distress over the condition. However, the coping process changed and asthmatic control improved even in the control group, perhaps because self-monitoring of asthmatic control for the study constituted a change in coping. This unanticipated result was entirely compatible with the Self-Regulation Model. The thesis dearly demonstrates value of the Self-Regulation Model in understanding asthma self-management and developing clinical interventions.

Family structure and breakfast consumption of 11-15 year old boys and girls in Scotland, 1994-2010 : a repeated cross-sectional study

2013-04-21T04:02:55Z

Abstract: Background The benefits of breakfast during childhood and adolescence have been reported previously though few studies have considered family structure inequalities in breakfast consumption. The proportion of young people living in non-traditional family types has increased in recent years, strengthening the need to describe and monitor the impact of the changing family unit on adolescent breakfast consumption. This study aimed to describe changes in daily breakfast consumption among adolescents in Scotland between 1994 and 2010, while also considering family structure inequalities, and the degree to which these have changed over time. Methods Data from the 1994, 1998, 2002, 2006 and 2010 Scottish Health Behaviour in School-aged Children (HBSC) surveys were analysed using logistic multilevel regression models for binary outcome variable daily breakfast consumption. Results Daily breakfast consumption among adolescents increased between 1994 and 2010, although there were differences by age and sex. In fact those aged over 14.5 years saw decreases in breakfast consumption, and girls saw significantly larger increases than boys. Daily breakfast consumption was more prevalent among adolescents from 'both parent' families, with lowest prevalence among those from single parent families. Trends in daily breakfast consumption between 1994 and 2010 also varied by family structure. While prevalence of daily breakfast consumption increased among those living with 'both parents', the largest proportion of the population, prevalence decreased over time among adolescents of single parent families, and particularly among those living with their father. Conclusions Family structure inequalities in daily breakfast consumption increased between 1994 and 2010, while breakfast consumption across the population as a whole increased. As the proportion of young people living in an alternative family structure continues to grow it is important to understand why these inequalities have increased and how these may be overcome. Possible reasons for family structure inequalities and their increase in recent years are discussed.

The regulation of haemopoietic stem cell and progenitor cell proliferation by humoral factors

2012-06-11T10:54:57Z

Abstract: The mechanisms which regulate the growth fraction of the haemopoietic stem cell (CFU-S) and granulocyte macrophage progenitor cell (GM-CFC) have been investigated. In normal murine bone marrow (NMBM) a small proportion of the CFU-S are synthesising DNA (-10%). In contrast, in the bone marrow from mice regenerating after treatment with cytotoxic drugs and in developing haemopoietic tissues such as murine fetal liver a large proportion of the CFU-S (-40%) are synthesising DNA. Medium conditioned by normal murine and human bone marrow cells inhibited the proliferation of rapidly cycling CFU-S from regenerating bone marrow. This inhibitor was contained in a 50-100K daltons ultrafiltration fraction. In contra-distinction medium conditioned by human fetal liver cells stimulated the proliferation of CFU-S from NMBM. The stimulator was produced by adherent cells and was contained in a 30-50K daltons ultrafiltration fraction. An alternative assay for the humoral regulators of CFU-S proliferation was developed. Different numbers of haemopoietic cells were injected into lethally irradiated mice. Five days later they were injected with 2iCi of 125IUdR and sacrificed 2 hours later. There was a linear relationship between the log 125IUdR uptake into the spleen and femur and the log cell dose injected. Pre-treatment of haemopoietic cells with an S-phase specific cytotoxic drug resulted in a reduction in the 125IUdR incorporation into the spleen. This enabled the kinetic properties of a haemopoietic stem cell population to be assessed and the humoral 111 factors which modulate the growth fraction of these cells to be investigated. At early stages of gestation (11-14 weeks) in human fetal liver few GM-CFC are synthesising DNA, whereas later in gestation (>14 weeks) a large proportion of GM-CFC are in S-phase, Moore and Williams (1973b). Incubation of NMBM GM-CFC (approx 40% in DNA synthesis) with a supernatant from an early human fetal liver (11-14 weeks) reduced the proportion synthesising DNA to <5%. In contrast, the proportion of murine GM-CFC synthesising DNA was not affected by incubation with a supernatant from a late human fetal liver (>14 weeks). GM-CFC that had been switched out of cycle by incubation with a supernatant from an early gestation human fetal liver were switched back into cycle following incubation with a late human fetal liver supernatant. The inhibitor and stimulator of GM-CFC proliferation were both produced by non-adherent cells and were contained in >100K and 30-50K daltons ultrafiltration fractions repectively. It is likely that changes in the relative levels of a proliferation inhibitor and stimulator throughout gestation might control the proportion of GM-CFC in cycle.

Defining a role for the peduncolopontine tegmental nucleus in striatal outflow

2012-06-07T08:41:50Z

Abstract: The pedunculopontine tegmental nucleus (PPTg) lies within the pontomesencephalon and contains cholinergic and non-cholinergic neurones. It has extensive afferent and efferent connections throughout the brain. Early research suggested a role for the PPTg in the mediation of locomotor activity, and it was believed to form the major substrate of the electrophysiologically identified mesencephalic locomotor region (rviLR). Studies using selective excitotoxic lesions of the PPTg demonstrated that it has no role in the mediation of spontaneous or nucleus accumbens-induced (NAcc) locomotion. However evidence has suggested that the cuneiform nucleus (CNF) and not the PPTg is the main locus of the .MLR. The effects of bilateral ibotenate CNF lesions on spontaneous and amphetamine-induced locomotion stimulated from the NAcc were therefore investigated. CNF lesions had no effect on either type of locomotor activity. Bilateral ibotenate lesions of the PPTg have been shown to influence the expression of orofacial stereotypies following administration of systemic amphetamine. Oral stereotypies can be elicited reliably by direct stimulation of the ventrolateral caudate-putamen (VLCP). This thesis sought to clarify the role of the PPTg in the mediation of oral stereotypies, by combining bilateral ibotenate lesions of the PPTg with direct microinjection of amphetamine into the VLCP. Lesions of the PPTg caused a shift in the dose response curve to amphetamine resulting in an increase in the incidence and intensity of oro facial stereotypies at lower doses. Thus the PPTg appears to have inhibitory control over the expression of orofacial behaviors. It is hypothesised that while neither the PPTg nor the CNF have a role in the mediation of locomotor activity per se they may provide an integrative functional role, which influences motor outflow. The role of the CNF in the transmission of nociception and a role for the PPTg in the mediation of striatal outflow is discussed.

Physical activity and perceived benefits and barriers in adults aged 55-74

2012-06-06T09:53:44Z

Abstract: In order to increase the number of older adults physically active enough to obtain the health benefits of exercise, inactive individuals must firstly be identified, and attention must then be focused on determinants of exercise amenable to change. This study set out to develop self-complete questionnaires for assessing activity status, and perceived benefits of, and barriers to, physical activity. Of 1456 questionnaires sent out to a random sample of adults aged 55-74 a usable return rate of 37.6% (n=548) was achieved. A principal components analysis of the benefits of physical activity revealed five factors (physical performance, social, weight control, enjoyment, and psychological), and of the barriers to physical activity, also five factors (opportunities, physical exertion, time, limiting health, and support). Alpha internal consistency coefficients for the 10 factors ranged from 0.64 to 0.92, and test-retest reliability coefficients from 0.56 to 0.87. A series of one-way ANOVAs revealed that, with the exception of the benefit weight control, there was a significant gradation in factor scores between active and inactive subjects as classified by 4-, 9-, and 5- point activity classification methods. Validity of the activity classifications was assessed in a subsample of 86 subjects against measures of strength, flexibility, aerobic fitness and objectively measured physical activity. Active and inactive subjects classified using the 4- and 9-point questionnaires differed significantly in 1-mile walk time and energy expenditure estimated by a Caltrac accelerometer. The 5-point questionnaire did not appear able to differentiate active and inactive subjects. Test-retest reliability of the questionnaires ranged from 0.62 to 0.73. The questionnaire developed from this work for measuring perceived benefits and barriers of older adults can be used in either practical or research settings. Further work is required to determine the accuracy of the physical activity questionnaires in identifying low-active individuals in the population.

The modified dental anxiety scale : UK general public population norms in 2008 with further psychometrics and effects of age

2013-04-21T02:02:16Z

Abstract: Background: The Modified Dental Anxiety Scale (MDAS) is a brief, self-complete questionnaire consisting of five questions and summed together to produce a total score ranging from 5 to 25. It has reasonable psychometric properties, low instrumental effects and can be integrated into everyday dental practice as a clinical aid and screen for dental anxiety. The objectives were to (i) produce confirmatory evidence of reliability and validity for the MDAS, (ii) provide up-to-date UK representative norms for the general public to enable clinicians to compare their patients' scores, (iii) to determine the nature of the relationship between dental anxiety and age. Methods: Telephone survey of a representative quota sample of 1000 UK adults (>18 years of age) conducted between 7–21 April, 2008. Results: Attrition of potential participants was high in the recruitment process, although bias was minimal. Estimated proportion of participants with high dental anxiety (cut-off score = 19) was 11.6%. Dental anxiety was four times greater in the youngest age group (18–39 yrs) compared to older participants (60+ yrs), controlling for sex, social class and self-reported dental visiting behaviour confirming previous developed-world reports. Conclusion: The scale's psychometrics is supportive for the routine assessment of patient dental anxiety to compare against a number of major demographic groups categorised by age and sex. Dental anxiety was high in younger compared to older people.

Targeting mitotic chromosomes : a conserved mechanism to ensure viral genome persistence

2013-04-21T01:38:10Z

Abstract: Viruses that maintain their genomes as extrachromosomal circular DNA molecules and establish infection in actively dividing cells must ensure retention of their genomes within the nuclear envelope in order to prevent genome loss. The loss of nuclear membrane integrity during mitosis dictates that paired host cell chromosomes are captured and organized by the mitotic spindle apparatus before segregation to daughter cells. This prevents inaccurate chromosomal segregation and loss of genetic material. A similar mechanism may also exist for the nuclear retention of extrachromosomal viral genomes or episomes during mitosis, particularly for genomes maintained at a low copy number in latent infections. It has been heavily debated whether such a mechanism exists and to what extent this mechanism is conserved among diverse viruses. Research over the last two decades has provided a wealth of information regarding the mechanisms by which specific tumour viruses evade mitotic and DNA damage checkpoints. Here, we discuss the similarities and differences in how specific viruses tether episomal genomes to host cell chromosomes during mitosis to ensure long-term persistence.

Clinical and cost-effectiveness of internal limiting membrane peeling for patients with idiopathic full thickness macular hole : Protocol for a Randomised Controlled Trial: FILMS (Full-thickness macular hole and Internal Limiting Membrane peeling Study)

2013-04-21T03:33:38Z

Abstract: Background: A full-thickness macular hole (FTMH) is a common retinal condition associated with impaired vision. Randomised controlled trials (RCTs) have demonstrated that surgery, by means of pars plana vitrectomy and post-operative intraocular tamponade with gas, is effective for stage 2, 3 and 4 FTMH. Internal limiting membrane (ILM) peeling has been introduced as an additional surgical manoeuvre to increase the success of the surgery; i.e. increase rates of hole closure and visual improvement. However, little robust evidence exists supporting the superiority of ILM peeling compared with no-peeling techniques. The purpose of FILMS (Full-thickness macular hole and Internal Limiting Membrane peeling Study) is to determine whether ILM peeling improves the visual function, the anatomical closure of FTMH, and the quality of life of patients affected by this disorder, and the cost-effectiveness of the surgery. Methods/Design: Patients with stage 2-3 idiopathic FTMH of less or equal than 18 months duration (based on symptoms reported by the participant) and with a visual acuity <= 20/40 in the study eye will be enrolled in this FILMS from eight sites across the UK and Ireland. Participants will be randomised to receive combined cataract surgery (phacoemulsification and intraocular lens implantation) and pars plana vitrectomy with postoperative intraocular tamponade with gas, with or without ILM peeling. The primary outcome is distance visual acuity at 6 months. Secondary outcomes include distance visual acuity at 3 and 24 months, near visual acuity at 3, 6, and 24 months, contrast sensitivity at 6 months, reading speed at 6 months, anatomical closure of the macular hole at each time point (1, 3, 6, and 24 months), health related quality of life (HRQOL) at six months, costs to the health service and the participant, incremental costs per quality adjusted life year (QALY) and adverse events. Discussion: FILMS will provide high quality evidence on the role of ILM peeling in FTMH surgery.

Local decision-makers views' of national guidance on interventional procedures in the UK

2013-04-21T03:33:37Z

Abstract: Objectives: To identify how decision-makers in the NHS perceive and manage interventional procedures guidance and to determine whether additional information would be useful. Methods: Qualitative study using semi-structured interviews with seven providers, six commissioners and one policy-maker. The framework approach was used to analyse transcribed data, and emergent themes coded. Data were analysed separately for providers and commissioner organizations. Results: Perceptions about how guidance is managed in provider organizations varied. Some decision-makers considered that guidance is handled very well whereas others think it is suboptimal and haphazard. It is unclear whether clinicians follow procedure for cautionary guidance. In commissioner organizations, guidance is not seen as a priority by most and is not considered an area that will soon enter routine clinical practice. Moreover, commissioners felt that guidance lacked relevance as there is no consideration of whether procedures are cost-effective or affordable. Despite this, respondents perceived that the content and quality of guidance is satisfactory. Useful additional information for inclusion in guidance would be: prevalence, incidence, cost, patients' views, consequences of using the new intervention, comparative information, effectiveness and cost-effectiveness. Conclusions: Management of interventional procedures guidance in the NHS can be improved. It is important to understand the ways in which guidance meets and fails to meet decision-makers' needs.

The introduction of new interventional procedures in the British National Health Service : A qualitative study

2013-04-21T03:33:31Z

Abstract: Objectives: To investigate how interventional procedures (IPs) are introduced into the British National Health Services and identify areas for improvement in the current process. Methods: Qualitative study using one to one semi-structured interviews. Using the framework approach, the data generated from 14 participants were analysed with coding of emergent themes. Data were analysed separately for providers and commissioner organisations. Results: Variations were observed in how IPs are introduced from both the provider and commissioner perspectives. Patterns of approaches allowed the development of models reflecting practice at each type of organisation: very structured in some places to, unstructured or almost non-existent in others. Factors affecting the decision to introduce a procedure include: immediate costs and benefits, numbers of people affected, training requirements, NICE guidance, nature of procedure, support from colleagues, incentives, public or policy-maker pressure, and aims of the institution. Monitoring was seen as a key area for improvement by many. Conclusions: These variations indicate that the process of introducing new IPs in the NHS can be improved. Factors affecting decision-making and problems have been identified. The results of our study could inform and help shape future processes of managing and the introduction of new procedures into the NHS. (C) 2010 Elsevier Ireland Ltd. All rights reserved.

The effectiveness of early lens extraction with intraocular lens implantation for the treatment of primary angle-closure glaucoma (EAGLE) : study protocol for a randomized controlled trial

2013-04-21T03:33:33Z

Abstract: Background: Glaucoma is the leading cause of irreversible blindness. Although primary open-angle glaucoma is more common, primary angle-closure glaucoma (PACG) is more likely to result in irreversible blindness. By 2020, 5.3 million people worldwide will be blind because of PACG. The current standard care for PACG is a stepped approach of a combination of laser iridotomy surgery (to open the drainage angle) and medical treatment (to reduce intraocular pressure). If these treatments fail, glaucoma surgery (eg, trabeculectomy) is indicated. It has been proposed that, because the lens of the eye plays a major role in the mechanisms leading to PACG, early clear lens extraction will improve glaucoma control by opening the drainage angle. This procedure might reduce the need for drugs and glaucoma surgery, maintain good visual acuity, and improve quality of life compared with standard care. EAGLE aims to evaluate whether early lens extraction improves patient-reported, clinical outcomes, and cost-effectiveness, compared with standard care. Methods/Design: EAGLE is a multicentre pragmatic randomized trial. All people presenting to the recruitment centres in the UK and east Asia with newly diagnosed PACG and who are at least 50 years old are eligible. The primary outcomes are EQ-5D, intraocular pressure, and incremental cost per quality adjusted life year (QALY) gained. Other outcomes are: vision and glaucoma-specific patient-reported outcomes, visual acuity, visual field, angle closure, number of medications, additional surgery (e. g., trabeculectomy), costs to the health services and patients, and adverse events. A single main analysis will be done at the end of the trial, after three years of follow-up. The analysis will be based on all participants as randomized (intention to treat). 400 participants (200 in each group) will be recruited, to have 90% power at 5% significance level to detect a difference in EQ-5D score between the two groups of 0.05, and a mean difference in intraocular pressure of 1.75 mm Hg. The study will have 80% power to detect a difference of 15% in the glaucoma surgery rate. Trial Registration: ISRCTN44464607.

Pre-validation methods for developing a patient reported outcome instrument

2013-04-21T03:33:29Z

Abstract: Background: Measures that reflect patients' assessment of their health are of increasing importance as outcome measures in randomised controlled trials. The methodological approach used in the pre-validation development of new instruments (item generation, item reduction and question formatting) should be robust and transparent. The totality of the content of existing PRO instruments for a specific condition provides a valuable resource (pool of items) that can be utilised to develop new instruments. Such 'top down' approaches are common, but the explicit pre-validation methods are often poorly reported. This paper presents a systematic and generalisable 5-step pre-validation PRO instrument methodology. Methods: The method is illustrated using the example of the Aberdeen Glaucoma Questionnaire (AGQ). The five steps are: 1) Generation of a pool of items; 2) Item de-duplication (three phases); 3) Item reduction (two phases); 4) Assessment of the remaining items' content coverage against a pre-existing theoretical framework appropriate to the objectives of the instrument and the target population (e. g. ICF); and 5) qualitative exploration of the target populations' views of the new instrument and the items it contains. Results: The AGQ 'item pool' contained 725 items. Three de-duplication phases resulted in reduction of 91, 225 and 48 items respectively. The item reduction phases discarded 70 items and 208 items respectively. The draft AGQ contained 83 items with good content coverage. The qualitative exploration ('think aloud' study) resulted in removal of a further 15 items and refinement to the wording of others. The resultant draft AGQ contained 68 items. Conclusions: This study presents a novel methodology for developing a PRO instrument, based on three sources: literature reporting what is important to patient; theoretically coherent framework; and patients' experience of completing the instrument. By systematically accounting for all items dropped after the item generation phase, our method ensures that the AGQ is developed in a transparent, replicable manner and is fit for validation. We recommend this method to enhance the likelihood that new PRO instruments will be appropriate to the research context in which they are used, acceptable to research participants and likely to generate valid data.

Developing the clinical components of a complex intervention for a glaucoma screening trial : a mixed methods study

2013-04-21T03:33:31Z

Abstract: Background: Glaucoma is a leading cause of avoidable blindness worldwide. Open angle glaucoma is the most common type of glaucoma. No randomised controlled trials have been conducted evaluating the effectiveness of glaucoma screening for reducing sight loss. It is unclear what the most appropriate intervention to be evaluated in any glaucoma screening trial would be. The purpose of this study was to develop the clinical components of an intervention for evaluation in a glaucoma (open angle) screening trial that would be feasible and acceptable in a UK eye-care service. Methods: A mixed-methods study, based on the Medical Research Council (MRC) framework for complex interventions, integrating qualitative (semi-structured interviews with 46 UK eye-care providers, policy makers and health service commissioners), and quantitative (economic modelling) methods. Interview data were synthesised and used to revise the screening interventions compared within an existing economic model. Results: The qualitative data indicated broad based support for a glaucoma screening trial to take place in primary care, using ophthalmic trained technical assistants supported by optometry input. The precise location should be tailored to local circumstances. There was variability in opinion around the choice of screening test and target population. Integrating the interview findings with cost-effectiveness criteria reduced 189 potential components to a two test intervention including either optic nerve photography or screening mode perimetry (a measure of visual field sensitivity) with or without tonometry (a measure of intraocular pressure). It would be more cost-effective, and thus acceptable in a policy context, to target screening for open angle glaucoma to those at highest risk but for both practicality and equity arguments the optimal strategy was screening a general population cohort beginning at age forty. Conclusions: Interventions for screening for open angle glaucoma that would be feasible from a service delivery perspective were identified. Integration within an economic modelling framework explicitly highlighted the trade-off between cost-effectiveness, feasibility and equity. This study exemplifies the MRC recommendation to integrate qualitative and quantitative methods in developing complex interventions. The next step in the development pathway should encompass the views of service users.

Association between common variation at the FTO locus and changes in Body Mass Index from infancy to late childhood : the complex nature of genetic association through growth and development

2013-04-21T03:06:30Z

Abstract: An age-dependent association between variation at the FTO locus and BMI in children has been suggested. We metaanalyzed associations between the FTO locus (rs9939609) and BMI in samples, aged from early infancy to 13 years, from 8 cohorts of European ancestry. We found a positive association between additional minor (A) alleles and BMI from 5.5 years onwards, but an inverse association below age 2.5 years. Modelling median BMI curves for each genotype using the LMS method, we found that carriers of minor alleles showed lower BMI in infancy, earlier adiposity rebound (AR), and higher BMI later in childhood. Differences by allele were consistent with two independent processes: earlier AR equivalent to accelerating developmental age by 2.37% (95% CI 1.87, 2.87, p = 10220) per A allele and a positive age by genotype interaction such that BMI increased faster with age (p = 10223). We also fitted a linear mixed effects model to relate genotype to the BMI curve inflection points adiposity peak (AP) in infancy and AR. Carriage of two minor alleles at rs9939609 was associated with lower BMI at AP (20.40% (95% CI: 20.74, 20.06), p = 0.02), higher BMI at AR (0.93% (95% CI: 0.22, 1.64), p = 0.01), and earlier AR (24.72% (25.81, 23.63), p = 10217), supporting cross-sectional results. Overall, we confirm the expected association between variation at rs9939609 and BMI in childhood, but only after an inverse association between the same variant and BMI in infancy. Patterns are consistent with a shift on the developmental scale, which is reflected in association with the timing of AR rather than just a global increase in BMI. Results provide important information about longitudinal gene effects and about the role of FTO in adiposity. The associated shifts in developmental timing have clinical importance with respect to known relationships between AR and both later-life BMI and metabolic disease risk.

Scottish Schools Adolescent Lifestyle and Substance Use Survey (SALSUS) national report : Smoking, drinking and drug use among 13 and 15 year olds in Scotland in 2004

2012-12-12T10:19:34Z

Anxiety reduction via brief intervention in dentally anxious patients : a randomized controlled trial

2012-12-12T12:53:11Z

Abstract: Aim: To compare the degree of anxiety reduction in dentally anxious patients attending a Dental Access Centre where the dentist did or did not receive the patients’ assessment of dental anxiety. Methods: Patients attending two Dental Access Centres in England, completed the Modified Dental Anxiety Scale (MDAS). Those that scored high completed a state anxiety questionnaire (STAI-S) and were randomized into three groups (n=182) to test the hypothesis that patients sharing assessment information about their dental anxiety to members of the dental team has beneficial effects on their state anxiety. Group 1 were controls (n=60), Group 2 gave their MDAS to the receptionist who passed it onto the dentist unknown to the patient (n=62) and Group 3 handed their MDAS to the dentist (n=60). After their appointment they repeated the STAI-S. Results and conclusion: Patients in Group 3 were less anxious (by more than STAI-S 3 scale units) on leaving the surgery than those from the other groups especially if they entered into a discussion with the dentist about their concerns (by more than 5 scale units). Brief assessment of dental anxiety shared by the patient with the dentist collaboratively has the potential to reduce anxiety on completion of the appointment. Dental anxiety is common, has a multifactorial aetiology, and is far from being homogenous, as individuals seem to differ in the origins, age of onset and manifestations of their dental fears (Locker et al., 2001b); (Milgrom et al., 1988). Previous negative experiences are a major factor in the development of dental anxiety (Kleinknect et al., 1973); (Bernstein et al., 1979); (de Jongh et al., 1995); (Locker et al., 1999); (Ost and Hugdahl, 1985). For some individuals, their fear of dentistry may be associated with concurrent anxiety disorders, or more general psychopathology (Locker, 2003); (Locker et al., 2001a).

Developing Fife Interprofessional Clinical Skills Model of Education for student clinical placements

2012-12-12T10:19:22Z

Abstract: End of pilot report for FICSME, an ACT funded initiative. Description: Funding of the pilot was provided by ACT from both NHS Fife and NHS Tayside.

Attitudes towards condom use among young people

2012-12-12T10:19:17Z

Sources of sexual health information among young people

2012-12-12T10:19:16Z

Sexual health among young people in Scotland

2012-12-12T10:19:15Z

Health Behaviour in School-aged Children : World Health Organization collaborative cross-national study (HBSC): findings from the 2010 HBSC survey in Scotland

2012-12-12T10:19:18Z

Abstract: The report, produced by CAHRU with funding support from NHS Health Scotland, provides a unique picture of the health of young people aged 11, 13 and 15 years in Scotland over the last two decades. Set against the social backdrop of family life, school experience, neighbourhood environment and peer relationships the report gives a comprehensive description of young people's health status. Please contact CAHRU (contact details) for further information about this research.

News from the international study Control of Adolescent Smoking : Comparing national policies on smoking in eight European countries

2012-12-12T10:19:20Z

News from the international study Control of Adolescent Smoking : Adolescent smoking trends and intentions to smoke in eight European countries

2012-12-12T10:19:19Z

Key findings from the 2006 Scottish Health Behaviour in School-aged Children study

2012-12-12T10:19:13Z

How are Scotland's young people doing? : A cross-national perspective on health-related risk

2012-12-12T10:19:04Z

Mental well-being among schoolchildren in Scotland : age and gender patterns, trends and cross-national comparisons

2012-12-12T10:18:59Z

Introduction, background and dissemination of the 2002 HBSC survey in Scotland

2012-12-12T10:18:58Z

Mental well-being of young people in Scotland : 1994-2006

2012-12-12T10:19:12Z

Perceptions of school and the health of schoolchildren

2012-12-12T10:19:11Z

Family affluence and health among schoolchildren

2012-12-12T10:19:09Z

Bullying : Health, well-being and risk behaviours

2012-12-12T10:19:08Z

Social context of bullying behaviours

2012-12-12T10:19:07Z

How are Scotland's young people doing? : A cross-national perspective on physical activity, TV viewing, eating habits, body image and oral hygiene

2012-12-12T10:19:05Z

How are Scotland’s young people doing? : A cross-national perspective on physical and emotional well-being

2012-12-12T10:19:03Z

Mental-health and well-being in the context of school : Young people in Scotland

2012-12-12T10:19:02Z

Gender matters : Physical activity patterns of schoolchildren in Scotland

2012-12-12T10:19:01Z

Family structure and relationships and health among schoolchildren

2012-12-12T10:19:10Z

Bullying and fighting among schoolchildren in Scotland : age and gender patterns, trends and cross-national comparisons

2012-12-12T10:19:06Z

Health Behaviour in School-aged Children : World Health Organization collaborative cross-national study (HBSC): findings from the 2006 HBSC survey in Scotland

2012-12-12T10:18:45Z

Validating mental well-being items of the Scottish Health Behaviour in School-aged Children (HBSC) Survey

2012-12-12T10:18:33Z

Description: This research was funded by NHS Health Scotland as a developmental part of the national HBSC study.

Young people's health in Great Britain and Ireland : Findings from the Health Behaviour in School-aged Children survey 2006

2012-12-12T10:18:37Z

Abstract: The report is produced by CAHRU with funding from NHS Health Scotland and in cooperation with its counterparts in England, Ireland and Wales. It shows findings from the International HBSC study providing an interesting picture on how Great Britain and Ireland are doing as a whole as well as comparing the individual countries with one another. Investigating various health issues and behaviours in young people as well as their social environment this report gives a new look at the 2006 HBSC findings. The report is considered to complement previous HBSC publications such as the "HBSC Scotland National Report" and the "Inequalities in Young people's Health" report. Description: Produced in cooperation with Centre for Research in Primary and Community Care, Hertfordshire; Welsh Assembly Government, Cardiff; Health Promotion Research Centre, Galway.

Identification of 2-aminothiazole-4-carboxylate derivatives active against Mycobacterium tuberculosis H37Rv and the beta-ketoacyl-ACP synthase mtFabH

2013-04-21T03:07:28Z

Abstract: Background: Tuberculosis (TB) is a disease which kills two million people every year and infects approximately over one-third of the world's population. The difficulty in managing tuberculosis is the prolonged treatment duration, the emergence of drug resistance and co-infection with HIV/AIDS. Tuberculosis control requires new drugs that act at novel drug targets to help combat resistant forms of Mycobacterium tuberculosis and reduce treatment duration. Methodology/Principal Findings: Our approach was to modify the naturally occurring and synthetically challenging antibiotic thiolactomycin (TLM) to the more tractable 2-aminothiazole-4-carboxylate scaffold to generate compounds that mimic TLM's novel mode of action. We report here the identification of a series of compounds possessing excellent activity against M. tuberculosis H37Rv and, dissociatively, against the beta-ketoacyl synthase enzyme mtFabH which is targeted by TLM. Specifically, methyl 2-amino-5-benzylthiazole-4-carboxylate was found to inhibit M. tuberculosis H37Rv with an MIC of 0.06 mu g/ml (240 nM), but showed no activity against mtFabH, whereas methyl 2-(2-bromoacetamido)-5-(3-chlorophenyl)thiazole-4-carboxylate inhibited mtFabH with an IC50 of 0.95 +/- 0.05 mu g/ml (2.43 +/- 0.13 mu M) but was not active against the whole cell organism. Conclusions/Significance: These findings clearly identify the 2-aminothiazole-4-carboxylate scaffold as a promising new template towards the discovery of a new class of anti-tubercular agents.

Polymorphisms of the steroid sulfatase (STS) gene are associated with attention deficit hyperactivity disorder and influence brain tissue mRNA expression

2013-04-21T02:34:57Z

Abstract: Previous studies in animals and humans have implicated the X-chromosome STS gene in the etiology of attentional difficulties and attention deficit hyperactivity disorder (ADHD). This family based association study has fine mapped a region of the STS gene across intron 1 and 2 previously associated with ADHD, in an extended sample of 450 ADHD probands and their parents. Significant association across this region is demonstrated individually with 7 of the 12 genotyped SNPs, as well as an allele specific haplotype of the 12 SNPs. The over transmitted risk allele of rs12861247 was also associated with reduced STS mRNA expression in normal human post-mortem frontal cortex brain tissue compared to the non-risk allele (P = 0.01). These results are consistent with the hypothesis arising from previous literature demonstrating that boys with deletions of the STS gene, and hence no STS protein are at a significantly increased risk of developing ADHD. Furthermore, this study has established the brain tissue transcript of STS, which except from adipose tissue, differs from that seen in all other tissues investigated. © 2010 Wiley-Liss, Inc. Description: Supported by Wellcome Trust funding

Provision of breast cancer risk information to women at the lower end of the familial risk spectrum

2013-04-21T01:33:07Z

Abstract: Background. Breast cancer family clinics provide risk information as one of their key functions. Many referrals to these clinics are 'low-risk' women. Objective: It was the aim of this study to report on the generic risk status letters and printed materials (in the form of leaflets) provided to this category of counselees by UK cancer genetics centres. Methods: A postal survey was conducted requesting information materials from genetic centres. Results: Personalized risk letters and/or printed materials were received from 16 of 22 familial cancer centres in the UK. Personalized risk letters and printed materials currently provided to these counselees display inconsistencies and over-simplification that may lead to misunderstanding. Conclusion: There is a need for collaboration among cancer genetics centres to design more helpful and consistent literature. Copyright (c) 2007 S. Karger AG, Basel.

Camera-related behaviours of female dental nurses and nursery school children during fluoride varnish application interactions in nursery school settings

2013-04-21T02:36:29Z

Abstract: Objective. To investigate camera awareness of female dental nurses and nursery school children as the frequency of camera-related behaviours observed during fluoride varnish applications in a community based health programme. Methods. Fifty-one nurse–child interactions (three nurse pairs and 51 children) were video recorded when Childsmile nurses were applying fluoride varnish onto the teeth of children in nursery school settings. Using a pre-developed coding scheme, nurse and child verbal and nonverbal behaviours were coded for camera-related behaviours. Results. On 15 of 51 interactions (29.4%), a total of 31 camera-related behaviours were observed for dental nurses (14 instances over nine interactions) and children (17 instances over six interactions). Camera-related behaviours occurred infrequently, occupied 0.3% of the total interaction time and displayed at all stages of the dental procedure, though tended to peak at initial stages. Conclusions. Certain camera-related behaviours of female dental nurses and nursery school children were observed in their interactions when introducing a dental health preventive intervention. Since the frequency of camera-related behaviours are so few they are of little consequence when video-recording adults and children undertaking dental procedures.

Hypotension in obstetric spinal anaesthesia: a lesson from pre-eclampsia

2011-04-28T09:13:03Z

Description: Editorial; Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815

Assessment of pulse transit time to indicate cardiovascular changes during obstetric spinal anaesthesia

2011-04-28T09:36:52Z

Abstract: Background. Pulse transit time (PTT) measurement may provide rapidly available beat-to-beat cardiovascular information when conditions change quickly and routine invasive arterial pressure measurement is not justified, for example during obstetric spinal anaesthesia. Method. We obtained ethics approval for an observational study of PTT during the onset of spinal anaesthesia in patients having elective or urgent Caesarean section. PTT was measured as the difference in time between the peak of the ECG R wave and the upstroke of the toe plethysmograph. Arterial pressure was measured by non-invasive sphygmomanometry. Results. We analysed data from 58 normotensive patients and 15 patients with pregnancy-induced hypertension (PIH). PTT increased with the onset of spinal anaesthesia as arterial pressure decreased. An increase of 20% in PTT was 74% sensitive and 70% specific in indicating a decrease in mean arterial pressure of more than 10%. Changes in PTT were related to changes in mean arterial pressure (r2=0.55, P<0.0001). Arterial pressure changes were greater and PTT increased significantly more quickly in the normotensive patients than in the patients with hypertension [median, quartiles: 32 (14, 56) ms min−1 compared with 7 (6, 18) ms min−1; P<0.01, Mann–Whitney U-test]. However, the relationship between PTT and arterial pressure was similar for the normotensive patients and the patients with PIH. Conclusion. PTT measurement gave a beat-to-beat indication of arterial pressure during spinal anaesthesia, and could be developed to allow prediction of the onset of hypotension. Description: Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815

Pulse transit time confirms altered response to spinal anaesthesia in pregnancy induced hypertension

2011-04-28T09:35:08Z

Description: Poster presented at the International Society for the Study of Hypertension in Pregnancy (ISSHP)Congress, Toronto 2002.; Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815

Pulse transit time confirms altered haemodynamic response to spinal anaesthesia in pregnancy induced hypertension

2011-04-28T09:35:42Z

Description: Original abstract presented at the International Society for the Study of Hypertension in Pregnancy (ISSHP)Congress, Toronto 2002 and published in the affiliated Journal 'Hypertension in Pregnancy'.; Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815

Pulse transit time: a new approach to haemodynamic monitoring in obstetric spinal anaesthesia

2011-04-28T09:34:02Z

Description: Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815; Original abstract presented at the Obstetric Anaesthetisits' Association congress 2002, Nottingham, 9-10 May.

Ephedrine requirements are reduced during spinal anaesthesia for caesarean section in preeclampsia

2011-04-28T09:21:07Z

Abstract: Background: Despite controversy over the haemodynamically safest blockade for caesarean section in women with severe preeclampsia, an increasing number of anaesthetists now opt for spinal anaesthesia. In a previous study we found that spinal compared to epidural anaesthesia offered an equally safe but more effective option for these patients. The current study was designed to compare the hypotension induced by spinal anaesthesia, as measured by ephedrine requirement, between 20 normotensive and 20 severely preeclamptic but haemodynamically stabilised women. Method: Standardised spinal anaesthesia was instituted and ephedrine was given in boluses of 6 mg if the systolic pressure fell >20% from the baseline, or if the patient exhibited symptoms of hypotension. Results: The mean ephedrine requirement of the normotensive group (27.9 ± 11.6 mg) was significantly greater (P < 0.01) than that of the preeclamptic group (16.4 ± 15.0 mg). Conclusion: This suggests that the hypotension induced by spinal anaesthesia in women with severe but haemodynamically stabilised preeclampsia, is less than that of normotensive patients. Description: Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815

Regional anaesthesia for caesarean section in severe preeclampsia: spinal anaesthesia is the preferred choice

2011-04-28T09:33:14Z

Abstract: Standard textbooks advocate epidural rather than spinal anaesthesia for caesarean section in severe preeclampsia. The basis for this recommendation is the theoretical risk of severe hypotension but no published scientific studies have been identified to support this assertion. We therefore designed a prospective study to compare spinal versus epidural anaesthesia in severely pre-eclamptic patients requiring hypotensive therapy. Following ethics committee approval, 28 women with preeclampsia requiring hypotensive medication who were scheduled for urgent (not emergency) or elective caesarean section consented to receive epidural or spinal anaesthesia by random assignment. Seven patients were excluded due to protocol violations. Four of these were in the epidural group of which two were excluded due to inadequate analgesia. No spinal patient was excluded because of inadequate analgesia. Mean ephedrine dosage was 5.2 mg (range 0–24 mg) in the spinal group and 6.3 mg (range 0–27 mg) in the epidural group. Six of the 11 patients in the spinal group required no ephedrine as did five of 10 in the epidural group. One patient in the spinal group suffered from mild intraoperative pain. By contrast in the epidural group three patients had mild pain and four others had pain severe enough to warrant intraoperative analgesia. There were no differences in neonatal outcomes. These findings support recent studies suggesting the safety and efficacy of spinal anaesthesia in this group of patients. Description: Part of the Portfolio Thesis by Geoffrey H. Sharwood-Smith: The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts, available at http://hdl.handle.net/10023/1815

The inferior vena caval compression theory of hypotension in obstetric spinal anaesthesia: studies in normal and preeclamptic pregnancy, a literature review and revision of fundamental concepts

2011-05-09T14:30:44Z

Abstract: Three clinical investigations together with a combined editorial and review of the cardiovascular physiology of spinal anaesthesia in normal and preeclamptic pregnancy form the basis of a thesis to be submitted for the degree of Doctor of Medicine at the University of St Andrews. First, the longstanding consensus that spinal anaesthesia could cause severe hypotension in severe preeclampsia was examined using three approaches. The doses of ephedrine required to maintain systolic blood pressure above predetermined limits were first compared in spinal versus epidural anaesthesia. The doses of ephedrine required were then similarly studied during spinal anaesthesia in preeclamptic versus normal control subjects. The principal outcome of these studies, that preeclamptic patients were resistant to hypotension after a spinal anaesthetic, was then further investigated by studying pulse transit time (PTT) changes in normal versus preeclamptic pregnancy. PTT was explored both as beat-to-beat monitor of cardiovascular function and also as an indicator of changes in arterial stiffness. The cardiovascular physiology of obstetric spinal anaesthesia was then reviewed in the light of the three clinical investigations, developments in reproductive vascular biology and the regulation of venous capacitance. It is argued that the theory of a role for vena caval compression as the single cause of spinal anaesthetic induced hypotension in obstetrics should be revised. Description: Full metadata records and copyright statements for publications contained in this portfolio thesis are available at the identifiers listed

The prevalence of dental anxiety across previous distressing experiences

2013-04-21T02:36:30Z

Abstract: Aims: To compare the prevalence of high dental anxiety across a variety of past distressing experiences with a previously reported Dutch sample. Method: University students from the UK (N=1024) completed an online survey containing; the Modified Dental Anxiety Scale, and the Level of Exposure-Dental Experiences Questionnaire (LOE-DEQ). Adjusted odds ratios (OR) were calculated to assess the association of self-reported distressing experiences and dental anxiety. Results: The percentage of respondents with high dental anxiety (HDA) (total MDAS score ≥19) was 11.2%. Significant prevalence of HDA across several distressing experiences was shown in both UK and Dutch samples notably: extreme helplessness during dental treatment, lack of understanding of the dentist and extreme embarrassment during dental treatment. There were little or no effects of non dental trauma, with the exception of sexual abuse in the UK sample. Conclusions: Trauma from various past experiences may be implicated in an increased risk of high dental anxiety.

Persistence of symptoms in veterans of the first Gulf War : 5-year follow-up

2013-04-21T01:33:06Z

Abstract: BACKGROUND: During the 1990-1991 Gulf War, approximately 700,000 U.S. troops were deployed to the Persian Gulf theater of operations. Of that number, approximately 100,000 have presented medical complaints through various registry and examination programs. OBJECTIVES: Widespread symptomatic illness without defining physical features has been reported among veterans of the 1991 Gulf War. We ascertained changes in symptom status between an initial 1995 symptom evaluation and a follow-up in 2000. METHODS: We assessed mailed symptom survey questionnaires for 390 previously surveyed members of the U.S. Department of Veterans Affairs Gulf War Registry for changes over the 5-year interval in terms of number and severity of symptoms. RESULTS: For the cohort as a whole, we found no significant changes in symptom number or severity. Those initially more symptomatic in 1995 showed some improvement over time, but remained much more highly symptomatic than those who had lesser initial symptomatology. CONCLUSIONS: The symptom outbreak following the 1991 Gulf War has not abated over time in registry veterans, suggesting substantial need for better understanding and care for these veterans.

Polymorphisms in gag spacer peptide 1 confer varying levels of resistance to the HIV-1 maturation inhibitor bevirimat

2013-04-21T02:03:32Z

Abstract: Background: The maturation inhibitor bevirimat (BVM) potently inhibits human immunodeficiency virus type 1 (HIV-1) replication by blocking capsid-spacer peptide 1 (CA-SP1) cleavage. Recent clinical trials demonstrated that a significant proportion of HIV-1-infected patients do not respond to BVM. A patient’s failure to respond correlated with baseline polymorphisms at SP1 residues 6-8. Results: In this study, we demonstrate that varying levels of BVM resistance are associated with point mutations at these residues. BVM susceptibility was maintained by SP1-Q6A, -Q6H and -T8A mutations. However, an SP1-V7A mutation conferred high-level BVM resistance and SP1-V7M and T8Δ mutations conferred intermediate levels of BVM resistance. Conclusions: Future exploitation of the CA-SP1 cleavage site as an antiretroviral drug target will need to overcome the baseline variability in the SP1 region of Gag.

Differential expression and functional characterization of luteinizing hormone receptor splice variants in human luteal cells : Implications for luteolysis

2013-04-21T02:32:47Z

Abstract: The human LH receptor (LHR) plays a key role in luteal function and the establishment of pregnancy through its interaction with the gonadotropins LH and human chorionic gonadotropin. We previously identified four splice variants of the LHR in human luteinized granulosa cells (LGCs) and corpora lutea (CL). Real-time quantitative PCR revealed that expression of the full-length LHR (LHRa) and the most truncated form (LHRd) changed significantly in CL harvested at different stages of the ovarian cycle (P < 0.01, ANOVA). LHRa expression was reduced in the late luteal CL (P<0.05). Conversely, an increase in LHRd expression was observed in the late luteal CL (P<0.01). Chronic manipulation of human chorionic gonadotropin in LGC primary cultures supported the in vivo findings. LHRd encodes a protein lacking the transmembrane and carboxyl terminal domains. COS-7 cells expressing LHRd were unable to produce cAMP in response to LH stimulation. COS-7 cells coexpressing LHRd and LHRa also failed to generate cAMP in response to LH, suggesting that this truncated form has a negative effect on the signaling of LHRa. Immunofluorescence staining ofLGC and COS-7 cells implied that there is a reduction in cell surface expression ofLHRa when LHRd is present. Overall, these results imply expression of LHR splice variants is regulated in the human CL. Furthermore, during functional luteolysis a truncated variant could modulate the cell surface expression and activity of full-length LHR.

Identification of a novel class of mammalian phosphoinositol-specific phospholipase C enzymes.

2010-12-07T15:29:17Z

Abstract: Phosphoinositol (PhoIns)-specific phospholipase C enzymes (PLCs) are central to the inositol lipid signaling pathways and contribute to intracellular Ca2+ release and protein kinase C activation. Five distinct classes of PhoIns-specific PLCs are known to exist in mammals, which are activated by membrane receptor-mediated events. Here we have identified a sixth class of PhoIns-specific PLC with a novel domain structure, which we have termed PLC-eta. Two putative PLC-eta enzymes were identified in humans and in mice. Sequence analysis revealed that residues implicated in substrate binding and catalysis from other PhoIns-specific PLCs are conserved in the novel enzymes. PLC-eta enzymes are most closely related to the PLC-delta class and share a close evolutionary relationship with other PLC isozymes. EST analysis and RT-PCR data suggest that PLC-eta enzymes are expressed in several cell types and, by analogy with other mammalian PhoIns-specific PLCs, are likely to be involved in signal transduction pathways.

The effects of leptomycin B on HPV-infected cells

2010-06-04T15:55:33Z

Abstract: Cervical cancer is a major cause of death in women and is strongly associated with infection by human papillomavirus (HPV). Integration of HPV is thought to form a key step in the formation of cancer, and is thought to involve the upregulation of HPV E6 and E7 due to the loss of E2 transcriptional control. Leptomycin B (LMB), a nuclear export inhibitor, has previously been shown to induce apoptosis in HPV-containing cancer cell lines and HPV 16 E7 or E6/E7 transduced primary keratinocytes, but not in normal cells. This thesis shows that LMB can induce apoptosis and a reduction in the colony survival of derivatives of the W12 cell line that contain HPV 16 in either episomal or integrated form. The HPV genome status, including variations in viral integration type, appears to influence the cumulative and temporal pattern of LMB-induced apoptosis. The effects of LMB were also apparent in cells grown in organotypic raft culture, with differences in behaviour again apparent between cells containing episomal and integrated HPV. As previously noted, treatment with LMB was associated with increased expression of the cell regulators p53 and p21; however, the induction of apoptosis was not dependent upon transcriptionally active p53. It is therefore likely that induction and mediation of LMB-induced apoptosis occurs via alternative, currently unidentified, pathways. These findings suggest that LMB can induce apoptosis in keratinocytes containing HPV 16 in either episomal or integrated form, with genome status and potentially lesion grade likely to influence the response of HPV-associated anogenital lesions to LMB treatment.

A role for topoisomerase II alpha in chromosome damage in human cell lines

2010-04-13T10:50:15Z

Abstract: Human response to ionising radiation (IR) shows a wide variation. This is most clearly seen in the radiation-response of cells as measured by frequencies of chromosomal aberrations. Different frequencies of IR-induced aberrations can be conveniently observed in phytohaemagglutin-stimulated peripheral blood T-lymphocytes from both normal individuals and sporadic cancer cases, in either metaphase chromosomes or as micronuclei in the following cell cycle. Metaphase cells show frequent chromatid breaks, defined as chromatid discontinuities or terminal deletions, if irradiated in the G 2 -phase of the cell cycle. It has been shown that the frequency of chromatid breaks in cells from approximately 40% of sporadic breast cancer patients, are significantly higher than in groups of normal individuals. This suggests that elevated radiation-induced chromatid break frequency may be linked with susceptibility to breast cancer. It is known that chromatid breaks are initiated by a double strand break (DSB), but it appears that the two are linked only indirectly as repair kinetics for DSBs and chromatid breaks do not match. Therefore, the underlying causes of the wide variation in frequencies of chromatid breaks in irradiated T-lymphocytes from different normal individuals and from sporadic breast cancer cases are still unclear but it is unlikely to be linked directly to DSB rejoining. My research has focused on the mechanism through which chromatid breaks are formed from initial DSBs. The lack of a direct association suggested that a signalling process might be involved, connecting the initial DSB and resulting chromatid break. The signal model, suggested that the initial DSB is located within a chromatin loop that leads to an intra- or interchromatid rearrangement resulting in incomplete mis-joining of chromatin ends during the decatenation of chromatids during G 2 . It was therefore proposed that topoisomerase II alpha (topo IIα) might be involved, mainly because of its ability to incise DNA and its role in sister chromatid decatenation. During my PhD research I have used a strategy of altering topo II activity or expression and studying whether this alters IR-induced chromatid break frequency. The first approach involved cell lines that varied in topo IIα expression. The frequency of IR-induced chromatid breaks was found to correlate positively with topo IIα expression level, as measured in three different cell lines by immunoblotting, i.e. two cell lines with lower topo IIα expression exhibited lower chromatid break frequency. Topo II activity in these three cell lines was also estimated indirectly by the ability of a topo IIα poison to activate the G 2 /M checkpoint, and this related well with topo IIα expression. A second approach involved ‘knocking down’ topo IIα protein expression by silencing RNA (siRNA). Lowered topo IIα expression was confirmed by immunoblotting and polymerase chain reaction. SiRNA-lowered topo IIα expression correlated with a decreased IR-induced chromatid break frequency. In a third series of experiments cells were treated with ICRF-193, a topo IIα catalytic inhibitor. It was shown that inhibition of topo IIα also significantly reduced IR-induced chromatid breaks. I also showed that lowered chromatid break frequency was not due to cells with high chromatid break frequencies being blocked in G 2 as the mitotic index was not altered significantly in cells with lowered topo IIα expression or activity. These experiments show that topo IIα is involved in IR-induced chromatid break formation. The final experiments reported here attempted to show how topo II might be recruited in the process of forming IR-induced chromatid breaks. Hydrogen peroxide was used as a source of reactive oxygen species (reported to poison topo IIα) and it was shown that topo IIα under these conditions is involved in the entanglement of metaphase chromosomes and formation of chromatin ‘dots’ as well as chromatid breaks. Experiments using atomic force microscopy attempted to confirm these dots as excised chromatin loops. The possible role of topo IIα in both radiation- and hydrogen peroxide-induced primary DNA damage was also tested. It was shown that topo IIα does not affect radiation-induced DSBs, even though it does affect chromatid break frequency. Also, topo IIα does not affect hydrogen peroxide-induced DNA damage at low doses. The results support the idea that topo IIα is involved in the conversion of DSBs to chromatid breaks after both irradiation and treatment with hydrogen peroxide at a low concentrations. I have demonstrated that topo IIα is involved in forming IR-induced chromatid breaks, most likely by converting the initial DSBs into chromosomal aberrations as suggested by the signal model.

Cell cycle control and its modulation in HPV infected cells

2010-02-24T15:57:29Z

Abstract: A key effect of human papillomavirus (HPV) infection is to disrupt the normal cell cycle in order to subvert the cellular DNA replication machinery. Morphologically, condylomata induced by high and low risk HPV types cannot be distinguished and many studies have shown that the pattern of viral gene expression is similar in condylomata caused by both high risk and low risk HPV types. Detailed morphological study of cell cycle protein expression has not previously been performed on condylomata infected with low risk HPV types. The findings presented suggest that the mechanisms employed by low risk HPV6 or HPV11 to subvert cellular functions in condylomata acuminata are similar to those employed by high risk HPVs, with the exception of cyclin D1 and p53 protein over-expression. The differences in p53 expression and cyclin D1 expression seen between high and low risk HPV infection, reflect the known differences between high and low risk types and are in agreement with the known differences between high risk and low risk E6 and E7 proteins. PHK transduction studies demonstrated HPV E6 and E7 induce changes in cell cycle protein expression and that there are differences in cell cycle abrogation between HPV6 and HPV16. Disruption of the p53-MDM2 interaction can lead to activation of the p53 pathway. HPV infected lesions almost always contain wild-type p53. The binding of HPV E6 to p53, and its subsequent targeting for degradation, prevents activation of the p53 pathway in HPV infected cells. Cells over expressing HPV genes were treated with Nutlin-3, a MDM2-small molecule antagonist. The findings presented suggest treatment with Nutlin-3 induces cell cycle arrest in cells expressing HPV16 E7 and HPV6 E6 and HPV6 E7. This suggests a potential role for Nutlin-3 in the treatment of HPV infected cells.

Development of a predictive DNA double strand break assay for the identification of individuals with high normal tissue radiosensitivity

2010-02-05T15:07:52Z

Abstract: A genetically determined high level of intrinsic normal tissue radiosensitivity may account for the 5% of patients who experience unexpectedly severe normal tissue side effects following radiotherapy. The pre-treatment identification of these individuals by a diagnostic test or “predictive assay “ may allow appropriate modification of treatment plans and improve the therapeutic index of radiotherapy. Results from studies of cell-based assays measuring the response of a single cell type taken from patients to in vitro irradiation have been inconsistent, leading to the opinion of many that they are of no value in the prediction of normal tissue radiosensitivity. A systematic review of the literature presented here, however, suggests that poor methodology of study design often with inadequate control for those factors other than normal tissue radiosensitivity which influence radiotherapy toxicity and lack of reporting of assay precision means that it is difficult to form any conclusions, positive or negative about the diagnostic accuracy of the cell-based assays studied so far. Analysis of individual patient data extracted from these studies suggests that at least some of these assays may possess some discriminatory value. This finding justified an attempt to develop a novel cell-based assay based on the kinetics of radiation-induced .H2AX in peripheral blood lymphocytes. Assay failure rate was high and intra- and inter-sample assay reproducibility was poor for quantification by microscopy but were better for flow cytometric analysis. A study of 8 volunteers, however, demonstrated that intra-individual variation was higher than inter-individual variation in assay results, strongly suggesting that poor assay reproducibility due to technical or biological factors may limit the assay’s potential to identify radiosensitive individuals. This suspicion needs to be confirmed in a clinical study of patients of known radiosensitivity. As blood sample storage conditions affect assay results these will need to be standardized to prevent confounding of results.

The role of HLA-B27 in inflammatory arthritis

2013-03-25T11:31:59Z

Abstract: The MHC class I allele, HLA-B27, is strongly associated with a group of inflammatory arthritic conditions collectively known as spondyloarthropathies (SpA). Ankylosing spondylitis (AS) shows the strongest association with 90-95 % of patients being HLA-B27 positive. The relationship between HLA-B27 and SpA has been known for over 30 years, however despite ongoing research, the reason for this association has not yet been elucidated. In more recent years, research has focused on intrinsic properties of the HLA-B27 allele, in particular its propensity to misfold, forming homodimers. It has been proposed that these homodimers could be associated with the disease process through the activation of an ER stress response known as the unfolded protein response (UPR), or through aberrant recognition at the cell surface. We have investigated whether the expression of HLA-B27 is associated with the activation of the UPR. We have studied the expression of BiP, and the cleavage of XBP1 and ATF6 using stable and transiently expressing cell lines. We have also investigated the formation of non-B27 homodimers using a human cell line stably expressing HLA-B8, and finally we have studied the expression of homodimers in exosomes, small immunomodulatory vesicles released from numerous cell types. The results presented here lead us to conclude that in vitro studies of the UPR are complicated, prone to a number of technical issues, and may therefore not be appropriate for gaining information that would be of significant use when comparing to the real disease scenario. Our data suggest that non-B27 dimers may be strongly influenced by both the overexpression of MHC class I heavy chains and also the redox environment within the cell. We have isolated a novel fully folded, beta-2m-associated, MHC class I homodimer in exosomes and have detected a novel HLA-A and HLA-B mixed heavy chain dimer. Our results suggest that these dimers form through interactions between the cysteine residues in the cytoplasmic tail and that these dimers form in exosomes because they contain lower levels of the important antioxidant glutathione when compared to whole cells. Together, these results define a new MHC class I structure present on exosomes at significant levels, which could potentially influence immune recognition by both antigen-specific T cell receptors and NK family receptors. The data also poses questions about whether these novel structures, when they involve HLA-B27, could influence the pathogenesis of spondyloarthropathies. Description: Electronic version excludes material for which permission has not been granted by the rights holder

Development of an in vitro model for investigating the properties of human prostate epithelial cells and prostatic carcinoma cells

2012-09-25T10:52:18Z

Abstract: Prostate cell lines were derived from two regions of prostate tissue from the same patient. The objective was to produce cell lines (as a useful in vitro model) from these two different regions which exhibit different properties for carcinoma development. The tissue was obtained from patients suffering from benign prostate hyperplasia undergoing trans-urethral resection. Tissue was taken from the deep (peripheral) and superficial (peri-urethral) areas. The cells were immortalised by transduction with constructs over expressing the cdk4 and hTERT genes. These cell lines were then characterised for their cellular phenotypes utilized for radiation transformation studies and utilized to investigate the role of plant derived polyphenols on normal and tumour cells. The cell line from the superficial region (P21s) was treated to fractionated doses of gamma radiation and a transformed cloned cell line was derived (P21s 40Gy (clone-a)). The cell line from the deep region (P21d) was found to consist of a mixed population of abnormal cells and a transformed cloned cell line was derived from it (P21d 0Gy (clone-a). In an attempt to obtain a normal P21d cell line cloned cell lines from early passage P21d cells were established. All seven cloned lines were abnormal with an average of 80 chromosomes per cell, invasive using a Matrigel assay and produced anchorage independent colonies. All cell lines were fully characterised with immunocytochemistry, chromosome analysis, invasion assays, and anchorage independent colony formation. P21s expressed basal cell markers (cytokeratin 5 (CK5) and 14), were positive for stem cell markers (prostate specific stem cell antigen PSCA, CK6), positive for p16, p63 and telomerase expression and negative for c-Myc expression. P21s was not invasive in a Matrigel assay and did not produce anchorage independent colony formation. P21d and P21d 0Gy (clone-a) also expressed CK5, CK14, PSCA, CK6, and telomerase but not p16 or p63 and showed an increase in expression of nuclear c-Myc, highly invasive and produced anchorage independent colonies. P21s 40Gy (clone-a) expressed CK5, CK14, PSCA, CK6, telomerase and p63, produced anchorage independent colonies, and was weakly positive for c-Myc expression. Spectral karyotyping analysis (SKY) showed P21s had a normal chromosome complement except an additional chromosome 20 whereas the P21s 40Gy (clone-a), P21d and P21d 0Gy (clone-a) cell lines had an abnormal chromosome complement with P21d and P21d 0Gy (clone-a) cell lines expressing multiple copies of every chromosome including loss of the Y chromosome. These results were echoed in the single nucleotide polymorphism chip (SNP) results which showed P21s as normal but P21d and P21d 0Gy (clone-a) to have large deletion and amplification regions that correlated with the SKY analysis. No differential cytotoxic response was noted between normal and abnormal cell lines including prostatic carcinoma cell lines LNCaP and PC-3 following treatment with strawberry polyphenol compounds. Most reports of a cytotoxic response to tumour cells in the literature did not compare the response to normal cells and used established cell lines. Human lymphocytes were also tested and all compounds were toxic in high doses. Polyphenol and ellagitannin rich polyphenol fractions were very cytotoxic and the anthocyanin rich fraction less toxic. In contrast to the lack of a direct differential cytotoxic effect, plant polyphenols did produce a protective effect to a carcinogenic insult. However a protective effect was noted via micronucleus assay with 3 hour incubation with the polyphenol rich fraction prior to radiation treatment. Finally, the expression and association of metabolic enzymes within the cells cytosol were investigated. The P21s cells were found to express both isoforms of LDH and so thought to be able to metabolise anaerobically and aerobically. P21d and P21d 0Gy (clone-a) cells were found to only express one isoform in the complex and so it was assumed that these cells favoured anaerobic metabolism of ATP in correlation to the Warburg effect. c-Myc association with compounds in the cell cytosol of P21s cells existed whereas, abnormal cells lost this association along with up-regulation of c-Myc expression and down stream targets of c-Myc in the nuclei. Thus these newly established human prostate cell lines provide a useful model system for investigating the biology of the prostate and prostate cancer.

Modification of the E1-pIX region of the adenovirus 5 genome for use in cancer gene therapy

2008-06-18T09:04:45Z

Abstract: Currently the use of adenoviruses in cancer gene therapy is limited by efficient delivery of the virus into the tumour cells, detargeting of the virus from the liver, and the efficient spread of the virus within the tumour. Rapid and easy modification of adenoviruses enables expression of different genes from the genome of an oncolytic virus. I developed a system where the E1-pIX region of the adenovirus 5 genome could be mutated via recombination of a recipient virus with the deleted E1-pIX region flanked by a loxP and an attB-site and an “addback” plasmid with the mutated E1-pIX region flanked by a loxP and an attP-site. The recipient virus was found not to be producible even on a pIX-complementing cell line. The pIX was further modified by fusing GFP, FCU1 and MMP7 to the C-terminus with a 2A sequence that enables the ribosome to skip one specific peptide bond enabling the expression of genes flanking this sequence. Two different 2A sequences were used: FMDV 2A (F2A) and PTV-1 2A (P2A). The pIX-P2A-GFP expressing virus was found to have similar heat stability, CPE, burst size and plaque size characteristics as the parental virus, whereas the pIX-F2A-GFP expressing virus was found to have reduced heat stability, CPE, burst size and smaller plaque size. The viruses expressing FCU1 and MMP7 were found only to be producible on a pIX-complementing cell line due to the low expression of pIX from these constructs. I concluded that 2A sequences can be used in the context of adenoviruses but optimisation of the sequence may be needed depending on the fusion partners.

Biomarkers of isoflavone intake : validity at high intakes

2007-07-18T14:29:41Z

Abstract: Isoflavones are biologically active plant chemicals (phytoestrogens) which are ordinarily present in human diets. There is considerable research interest in their potential to prevent or treat several chronic diseases. Biomarkers can demonstrate compliance during dietary interventions and validate associations between intake of isoflavones and health outcomes. The objectives of this study were to validate 24-hour urine collections, timed spot urine samples and timed plasma samples as biomarkers of isoflavone intake up to 165mg/day. Healthy volunteers (20 women and 11 men) consumed 55mg/d, 110mg/d or 165mg/d soy isoflavones or placebo for seven consecutive days in a randomised, double-blind, crossover study. Timed blood samples, timed spot urine samples (taken in the afternoon, 5-7 hours after consuming the isoflavone supplement) and 24-hour urines were obtained at baseline and during each intervention. Isoflavone content of the samples was assayed by liquid chromatography and mass spectrometry. 24-hour urines were validated by percentage PABA recovery. The relationship between daily isoflavone intake and 24-hour urinary isoflavone excretion was: y = 6.63132xº•⁷⁴²¹ ≡ x = (y ÷ 6.63132)¹•³⁴⁷⁵ where y = isoflavone excretion in μg/24h and x = isoflavone intake in μg/24h r² = 0.86; p < 0.001; n = 109 samples from 31 volunteers. The relationship between daily isoflavone intake and plasma isoflavone concentration was: y = (3.3543x10⁻³)xº•⁴⁸⁸⁹ ≡ x = (y ÷ 3.3543x10⁻³)²•º⁴⁵⁴ where y = plasma isoflavone in μg/ml and x = isoflavone intake in μg/24h r² = 0.61; p < 0.001; n = 100 samples from 30 volunteers. The relationship between daily isoflavone intake and spot urine isoflavone concentration was: y = (2.0324x10⁻³)xº•⁸ºº⁹ ≡ x = (y ÷ 2.0324x10⁻³)¹•²⁴⁸⁶ where y = isoflavone excretion in μg/ml and x = isoflavone intake in μg/24h r² = 0.69; p < 0.001; n = 143 samples from 31 volunteers. It was concluded that 24-hour urine collections, timed plasma samples and timed spot urine samples are valid biomarkers of isoflavone intakes up to 165mg/day. A curvilinear relationship was defined between a) isoflavone dose and bioavailability in plasma and b) isoflavone dose and 24-hour urinary excretion.