571 research outputs found
The association between retinal vascular geometry changes and diabetic retinopathy and their role in prediction of progression: an exploratory study
Background: The study describes the relationship of retinal vascular geometry (RVG) to severity of diabetic retinopathy (DR), and its predictive role for subsequent development of proliferative diabetic retinopathy (PDR). Methods. The research project comprises of two stages. Firstly, a comparative study of diabetic patients with different grades of DR. (No DR: Minimal non-proliferative DR: Severe non-proliferative DR: PDR) (10:10: 12: 19). Analysed RVG features including vascular widths and branching angles were compared between patient cohorts. A preliminary statistical model for determination of the retinopathy grade of patients, using these features, is presented. Secondly, in a longitudinal predictive study, RVG features were analysed for diabetic patients with progressive DR over 7 years. RVG at baseline was examined to determine risk for subsequent PDR development. Results: In the comparative study, increased DR severity was associated with gradual vascular dilatation (p = 0.000), and widening of the bifurcating angle (p = 0.000) with increase in smaller-child-vessel branching angle (p = 0.027). Type 2 diabetes and increased diabetes duration were associated with increased vascular width (p = <0.05 In the predictive study, at baseline, reduced small-child vascular width (OR = 0.73 (95 CI 0.58-0.92)), was predictive of future progression to PDR. Conclusions: The study findings suggest that RVG alterations can act as novel markers indicative of progression of DR severity and establishment of PDR. RVG may also have a potential predictive role in determining the risk of future retinopathy progression. © 2014 Habib et al.; licensee BioMed Central Ltd
Somatostatin receptor 5 and cannabinoid receptor 1 activation inhibit secretion of glucose-dependent insulinotropic polypeptide from intestinal K cells in rodents.
AIMS/HYPOTHESIS: Glucose-dependent insulinotropic polypeptide (GIP) is an enteroendocrine hormone that promotes storage of glucose and fat. Its secretion from intestinal K cells is triggered by nutrient ingestion and is modulated by intracellular cAMP. In view of the proadipogenic actions of GIP, this study aimed to identify pathways in K cells that lower cAMP levels and GIP secretion. METHODS: Murine K cells purified by flow cytometry were analysed for expression of G(αi)-coupled receptors by transcriptomic microarrays. Somatostatin and cannabinoid receptor expression was confirmed by quantitative RT-PCR. Hormone secretion in vitro was measured in GLUTag and primary murine intestinal cultures. cAMP was monitored in GLUTag cells using the genetically encoded sensor Epac2-camps. In vivo tolerance tests were performed in cannulated rats. RESULTS: Purified murine K cells expressed high mRNA levels for somatostatin receptors (Sstrs) Sstr2, Sstr3 and Sstr5, and cannabinoid receptor type 1 (Cnr1, CB1). Somatostatin inhibited GIP and glucagon-like peptide-1 (GLP-1) secretion from primary small intestinal cultures, in part through SSTR5, and reduced cAMP generation in GLUTag cells. Although the CB1 agonist methanandamide (mAEA) inhibited GIP secretion, no significant effect was observed on GLP-1 secretion from primary cultures. In cannulated rats, treatment with mAEA prior to an oral glucose tolerance test suppressed plasma GIP but not GLP-1 levels, whereas the CB1 antagonist AM251 elevated basal GIP concentrations. CONCLUSIONS/INTERPRETATION: GIP release is inhibited by somatostatin and CB1 agonists. The differential effects of CB1 ligands on GIP and GLP-1 release may provide a new tool to dissociate secretion of these incretin hormones and lower GIP but not GLP-1 levels in vivo
Search for new physics in the multijet and missing transverse momentum final state in proton-proton collisions at √s=8 Tev
Peer reviewe
Measurement of Higgs boson production and properties in the WW decay channel with leptonic final states
Peer reviewe
Study of double parton scattering using W+2-jet events in proton-proton collisions at √s=7 TeV
Peer reviewe
Measurements of the tt¯ charge asymmetry using the dilepton decay channel in pp collisions at √s=7 TeV
Peer reviewe
Breathing adapted radiotherapy: a 4D gating software for lung cancer
<p>Abstract</p> <p>Purpose</p> <p>Physiological respiratory motion of tumors growing in the lung can be corrected with respiratory gating when treated with radiotherapy (RT). The optimal respiratory phase for beam-on may be assessed with a respiratory phase optimizer (RPO), a 4D image processing software developed with this purpose.</p> <p>Methods and Materials</p> <p>Fourteen patients with lung cancer were included in the study. Every patient underwent a 4D-CT providing ten datasets of ten phases of the respiratory cycle (0-100% of the cycle). We defined two morphological parameters for comparison of 4D-CT images in different respiratory phases: tumor-volume to lung-volume ratio and tumor-to-spinal cord distance. The RPO automatized the calculations (200 per patient) of these parameters for each phase of the respiratory cycle allowing to determine the optimal interval for RT.</p> <p>Results</p> <p>Lower lobe lung tumors not attached to the diaphragm presented with the largest motion with breathing. Maximum inspiration was considered the optimal phase for treatment in 4 patients (28.6%). In 7 patients (50%), however, the RPO showed a most favorable volumetric and spatial configuration in phases other than maximum inspiration. In 2 cases (14.4%) the RPO showed no benefit from gating. This tool was not conclusive in only one case.</p> <p>Conclusions</p> <p>The RPO software presented in this study can help to determine the optimal respiratory phase for gated RT based on a few simple morphological parameters. Easy to apply in daily routine, it may be a useful tool for selecting patients who might benefit from breathing adapted RT.</p
[11C]acetate PET/CT Visualizes Skeletal Muscle Exercise Participation, Impaired Function, and Recovery after Hip Arthroplasty; First Results
Based on skeletal muscle acetate physiology we aimed studying muscle function after hip arthroplasty with [(11)C]acetate PET
A critique of the WHO TobReg's "Advisory Note" report entitled: "Waterpipe tobacco smoking: health effects, research needs and recommended actions by regulators"
BACKGROUND AND AIM: The World Health Organisation Study Group on Tobacco Product Regulation (TobReg) has issued in 2005 an "Advisory Note" entitled: "Waterpipe Tobacco Smoking: Health Effects, Research Needs and Recommended Actions by Regulators". "Waterpipe" smoking is now considered a global public health threat and the corresponding artefact is actually known in the world under three main terms: hookah, narghile and shisha. This important report, the first ever prepared by WHO on the subject, poses two major problems. On one hand, its bibliographical references dismiss world chief relevant studies. On the other, it contains a certain number of errors of many orders: biomedical, sociological, anthropological and historical. The purpose of the present study is to highlight, one by one, where these weaknesses and errors lie and show how this official report can be considerably improved. RESULTS: We realise that widely advertised early anthropological studies were not taken into consideration whereas they shed a substantial light on this peculiar form of smoking and help understanding its high complexity. As for concrete errors to be found in this report, they deal with the chemistry of smoke, health-related effects, smoking patterns, description and history of the artefact and its use, gender and underage use aspects, prevention and research needs in this field. CONCLUSION: The scientific credibility of an international expert report may be at stake if its recommendations do not rely on sound objective research findings and a comprehensive review of the existing literature. The critical comments in this study will certainly help improve the present WHO report
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