982 research outputs found

    DNA methylation changes associated with acquired platinum resistance in ovarian cancer

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    Despite high responses to initial chemotherapy most patients with ovarian cancer (OC) relapse and inevitably die from their disease. Aberrant DNA methylation is frequently seen in ovarian tumours and may provide biomarkers of clinical outcome or insight into mechanisms of chemoresistance. We firstly performed Differential Methylation Hybridisation (DMH) to identify loci that gained methylation between 34 matched cisplatin sensitive and resistant OC tumour cell lines. Differentially methylated loci identified were further validated by Methylation Specific PCR (MSP) and bisulphite pyrosequencing. Selected loci were further investigated for association with clinical outcome in primary OC tumour samples and matched tumour samples from patients' pre- and post-chemotherapy. Frequent increased methylation of a CpG island at the NR2E1 gene was identified in this experiment. Increased methylation correlated with decreased gene expression and could be reversed following treatment with a demethylating agent. Increased methylation at NR2E1 was observed between matched pre- and post-treatment tumour pairs. A novel biostatistical method, methylation linear discrimination analysis (MLDA), was next used to identify differentially methylated loci in sensitive and resistant A2780 human ovarian cell lines. Eight of nine loci identified were validated by MSP. A locus at the SP5 gene was further investigated by pyrosequencing and found to show a very high level methylation in most cell lines and ovarian tumours. Increased methylation correlated with decreased gene expression and this could be reversed using decitabine treatment. Knockdown of SP5 expression caused increased apoptosis. DMH was next used to identify loci that gained methylation between 3 in vivo derived matched sensitive and resistant cell lines. KIAA1383, a gene of unknown function, was identified and methylation shown to correlate with response to chemotherapy and progression-free survival (PFS) in patients with OC. Over-expression was found to attenuate the response to cisplatin, in the PEA2 cell line, as measured by cell cycle analysis

    Multiple isolated aneurysms in a case of “burned out” Takayasu aortitis

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    AbstractTakayasu aortitis (TA) is a chronic inflammatory disease predominantly seen in young Asian women. The disease is idiopathic and largely affects the aorta and its major branches. The basic pathologic changes in TA are fibrosis and subsequent occlusion of the large arteries. TA is classically termed “pulseless” disease, with manifestations during the occlusive stage including limb ischemia, renovascular hypertension, and heart failure. Arterial dilation and aneurysm are largely unappreciated manifestations of TA, but they occur in as many as 32% of affected patients. We report chronic “burned out” TA in a 23-year-old Hispanic woman with isolated aneurysms of the descending thoracic aorta, abdominal aorta, and common iliac arteries, without occlusive disease. (J Vasc Surg 2003;37:1094-7.

    Expression of KOC, S100P, mesothelin and MUC1 in pancreatico-biliary adenocarcinomas: development and utility of a potential diagnostic immunohistochemistry panel

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    <b>Background</b> Pancreatico-biliary adenocarcinomas (PBA) have a poor prognosis. Diagnosis is usually achieved by imaging and/or endoscopy with confirmatory cytology. Cytological interpretation can be difficult especially in the setting of chronic pancreatitis/cholangitis. Immunohistochemistry (IHC) biomarkers could act as an adjunct to cytology to improve the diagnosis. Thus, we performed a meta-analysis and selected KOC, S100P, mesothelin and MUC1 for further validation in PBA resection specimens.<p></p> <b>Methods</b> Tissue microarrays containing tumour and normal cores in a ratio of 3:2, from 99 surgically resected PBA patients, were used for IHC. IHC was performed on an automated platform using antibodies against KOC, S100P, mesothelin and MUC1. Tissue cores were scored for staining intensity and proportion of tissue stained using a Histoscore method (range, 0–300). Sensitivity and specificity for individual biomarkers, as well as biomarker panels, were determined with different cut-offs for positivity and compared by summary receiver operating characteristic (ROC) curve.<p></p> <b>Results</b> The expression of all four biomarkers was high in PBA versus normal ducts, with a mean Histoscore of 150 vs. 0.4 for KOC, 165 vs. 0.3 for S100P, 115 vs. 0.5 for mesothelin and 200 vs. 14 for MUC1 (p < .0001 for all comparisons). Five cut-offs were carefully chosen for sensitivity/specificity analysis. Four of these cut-offs, namely 5%, 10% or 20% positive cells and Histoscore 20 were identified using ROC curve analysis and the fifth cut-off was moderate-strong staining intensity. Using 20% positive cells as a cut-off achieved higher sensitivity/specificity values: KOC 84%/100%; S100P 83%/100%; mesothelin 88%/92%; and MUC1 89%/63%. Analysis of a panel of KOC, S100P and mesothelin achieved 100% sensitivity and 99% specificity if at least 2 biomarkers were positive for 10% cut-off; and 100% sensitivity and specificity for 20% cut-off.<p></p> <b>Conclusion</b> A biomarker panel of KOC, S100P and mesothelin with at least 2 biomarkers positive was found to be an optimum panel with both 10% and 20% cut-offs in resection specimens from patients with PBA.<p></p&gt

    The SCottish Alcoholic Liver disease Evaluation: a population-level matched cohort study of hospital-based costs, 1991-2011

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    Studies assessing the costs of alcoholic liver disease are lacking. We aimed to calculate the costs of hospitalisations before and after diagnosis compared to population controls matched by age, sex and socio-economic deprivation. We aimed to use population level data to identify a cohort of individuals hospitalised for the first time with alcoholic liver disease in Scotland between 1991 and 2011.Incident cases were classified by disease severity, sex, age group, socio-economic deprivation and year of index admission. 5 matched controls for every incident case were identified from the Scottish population level primary care database. Hospital costs were calculated for both cases and controls using length of stay from morbidity records and hospital-specific daily rates by specialty. Remaining lifetime costs were estimated using parametric survival models and predicted annual costs. 35,208 incident alcoholic liver disease hospitalisations were identified. Mean annual hospital costs for cases were 2.3 times that of controls pre diagnosis (£804 higher) and 10.2 times (£12,774 higher) post diagnosis. Mean incident admission cost was £6,663. Remaining lifetime cost for a male, 50-59 years old, living in the most deprived area diagnosed with acoholic liver disease was estimated to be £65,999 higher than the matched controls (£12,474 for 7.43 years remaining life compared to £1,224 for 21.8 years). In Scotland, alcoholic liver disease diagnosis is associated with significant increases in admissions to hospital both before and after diagnosis. Our results provide robust population level estimates of costs of alcoholic liver disease for the purposes of health-care delivery, planning and future cost-effectiveness analyses

    High-sensitivity Gd3+-Gd3+ EPR distance measurements that eliminate artefacts seen at short distances

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    We would like to acknowledge EPSRC (EP/R)13705/1) for current funding on the HiPER project, and the Wellcome Trust for a multi-user equipment grant (099149/Z/12/Z) for upgrades on the Q-band system. We thank the Royal Society for an International Exchanges Grant and The Weizmann-UK Joint Research Program for allowing bilateral travel and research between the University of St Andrews and the Weizmann Institute of Science. JEL thanks the Royal Society for a University Research Fellowship. MJT thanks EPSRC for a CM-CDT studentship (EP/LO15110/1). MQ and AG thank the Deutsche Forschungsgemeinschaft (DFG) for funding within SPP 1601 (GO555/6-2).Gadolinium complexes are attracting increasing attention as spin labels for EPR dipolar distance measurements in biomolecules and particularly for in-cell measurements. It has been shown that flip-flop transitions within the central transition of the high spin Gd3+ ion can introduce artefacts in dipolar distance measurements, particularly when measuring distances less than 3–4 nm. Previous work has shown some reduction of these artefacts through increasing the frequency separation between the two frequencies required for the Double Electron-Electron Resonance (DEER) experiment. Here we use a high power (1 kW), wideband, non-resonant, system operating at 94 GHz to evaluate DEER measurement protocols using two rigid Gd(III)-rulers, consisting of two [GdIII(PyMTA)] complexes, with separations of 2.1 nm and 6.0 nm, respectively. We show that by avoiding the |−1/2⟩ → |1/2⟩ central transition completely, and placing both the pump and the observer pulses on either side of the central transition, we can now observe apparently artefact-free spectra and narrow distance distributions, even for a Gd-Gd distance of 2.1 nm. Importantly we still maintain excellent signal-to-noise ratio and relatively high modulation depths. These results have implications for in-cell EPR measurements at naturally occurring biomolecule concentrations.Publisher PDFPeer reviewe

    A theory-based approach to understanding condom errors and problems reported by men attending an STI clinic

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    The official published version can be accessed from the link below - Copyright @ 2008 Springer VerlagWe employed the information–motivation–behavioral skills (IMB) model to guide an investigation of correlates for correct condom use among 278 adult (18–35 years old) male clients attending a sexually transmitted infection (STI) clinic. An anonymous questionnaire aided by a CD-recording of the questions was administered. Linear Structural Relations Program was used to conduct path analyses of the hypothesized IMB model. Parameter estimates showed that while information did not directly affect behavioral skills, it did have a direct (negative) effect on condom use errors. Motivation had a significant direct (positive) effect on behavioral skills and a significant indirect (positive) effect on condom use errors through behavioral skills. Behavioral skills had a direct (negative) effect on condom use errors. Among men attending a public STI clinic, these findings suggest brief, clinic-based, safer sex programs for men who have sex with women should incorporate activities to convey correct condom use information, instill motivation to use condoms correctly, and directly enhance men’s behavioral skills for correct use of condoms

    Molecular selection of therapy in metastatic colorectal cancer: the FOCUS4 molecularly stratified RCT

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    Complex trials with innovative designs are becoming increasingly common and offer the potential to improve patient outcomes in a shorter time frame. There is evidence that patients with colorectal cancer fall into different subgroups with varying responsiveness to therapy, and that this variation is linked to genetic biomarkers. To the best of our knowledge, FOCUS4 was the first molecularly stratified trial in metastatic colorectal cancer and remains one of the first umbrella trial designs to be launched globally. Objectives To identify novel therapies that improve disease control within the molecular subgroup of metastatic colorectal cancer in which the novel therapies were expected to be most effective. Design This was a Phase II/III molecularly stratified umbrella trial that used adaptive statistical methodology to decide which subtrial should close early; new subtrials were added as protocol amendments. Setting The maintenance setting following 16 weeks of first-line combination chemotherapy. Participants Patients with newly diagnosed metastatic colorectal cancer were registered, and central laboratory testing was used to stratify their tumour into molecular subtypes. Following 16 weeks of first-line therapy, patients with stable or responding disease were eligible for randomisation into either a molecularly stratified subtrial or the non-stratified FOCUS4-N trial. Interventions Of the 20 drug combinations that were explored for inclusion in the platform trial, three molecularly targeted subtrials were activated: FOCUS4-B (PIK3CA mutation or PTEN overexpression) – aspirin versus placebo; FOCUS4-C (TP53 and RAS mutation) – adavosertib (AstraZeneca Ltd, Cambridge, UK) versus active monitoring; and FOCUS4-D (BRAF-PIK3CA-RAS wild type) – AZD8931 versus placebo. A non-stratified subtrial was also carried out: FOCUS4-N – capecitabine versus active monitoring. Main outcome measures The main outcome measure was progression-free survival from the time of randomisation to progression, comparing the intervention with active monitoring/placebo. Toxicity and overall survival data were collected in all randomised patients, and quality of life (using EuroQol-5 Dimensions) data were collected in FOCUS4-N only. Results Between January 2014 and October 2020, 1434 patients were registered from 88 hospitals in the UK. Successful biomarker testing was completed in 1291 out of 1382 samples (93%), and 908 out of 1315 patients (69%) completing 16 weeks of first-line therapy were eligible for randomisation, with 361 randomly allocated to a subtrial. FOCUS4-B evaluated aspirin versus placebo in the PIK3CA-mutant/ PTEN -loss subgroup, but recruited only six patients, so was closed for futility. FOCUS4-C evaluated adavosertib versus active monitoring in 67 patients in the RAS + TP53 double-mutant subgroup and met its primary end point, showing an improvement in progression-free survival (median 3.61 vs. 1.87 months; hazard ratio 0.35, 95% confidence interval 0.18 to 0.68; p = 0022). FOCUS4-D evaluated AZD8931 in 32 patients in the BRAF-PIK3CA-RAS wild-type subgroup and showed no benefit, so was discontinued after the first interim analysis. FOCUS4-N evaluated capecitabine monotherapy versus active monitoring in 254 patients and met its primary end point, showing improvement in progression-free survival (hazard ratio 0.40, 95% confidence interval 0.21 to 0.75; p < 0.0001). Limitations FOCUS4-C and FOCUS4-N were closed early owing to COVID-19, so did not accrue their planned recruitment numbers. Conclusions Adaptive stratified medicine studies are feasible in common cancers but present challenges. Capecitabine monotherapy is an effective maintenance therapy. Wee1 inhibition using adavosertib shows significant clinical activity, notably in left-sided colorectal cancer. Trial registration This trial was registered as ISRCTN90061546. Funding This project was jointly funded by the Efficacy and Mechanism Evaluation (EME) programme, a MRC and National Institute for Health and Care Research (NIHR) partnership, and Cancer Research UK. This will be published in full in Efficacy and Mechanism Evaluation; Vol. 9, No. 9. See the NIHR Journals Library website for further project information

    Remotely-Sensing Chemical Diversity and Function of Native Plants Across Sagebrush-Steppe Landscapes

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    Plant chemical diversity provides ecosystem services by supporting wildlife diversity and offering sources for novel medicines. Current mapping of phytochemicals can be expensive, time-intensive and provides only a snapshot of available diversity. To overcome this, I will use handheld and airborne instruments collecting near infrared spectra and hyperspectral imagery to remotely sense chemical diversity within plants and ecosystems. I hypothesize that greater plant chemical diversity will be correlated with greater habitat use by wildlife and greater bioactivity of plant extracts. This research provides a powerful tool to map chemical diversity, target wildlife conservation and direct the discovery of novel medicines
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