670 research outputs found
Carnosine scavenging of glucolipotoxic free radicals enhances insulin secretion and glucose uptake
The worldwide prevalence of diabetes has risen to 8.5% among adults, which represents a staggering rise in prevalence from 4.7% in 1980. Whilst some treatments work by increasing insulin secretion, over time their effectiveness decreases. We aim to increase insulin secretion by developing strategies that work through mechanisms independent of current treatment options. Isolated CD1 mouse islets, INS-1 pancreatic β-cells, or C2C12 mouse myotubes were incubated in standard tissue culture media, or media supplemented with 28 mM glucose, 200 μM palmitic acid, and 200 μM oleic acid as a cellular model of diabetic glucolipotoxicity. Intracellular reactive species content was assayed using 2′,7′-dichlorofluorescein diacetate dye, inducible nitric oxide synthase levels determined by Western blot, 3-nitrotyrosine and 4-hydrpxnonenal both assayed by ELISA, insulin secretion quantified using ELISA or radioimmunoassay, and glucose uptake determined through 2-deoxy glucose 6 phosphate luminescence. Our data indicate that carnosine, a histidine containing dipeptide available through the diet, is an effective scavenger of each of the aforementioned reactive species. This results in doubling of insulin secretion from isolated mouse islets or INS-1 β-cells. Crucially, carnosine also reverses glucolipotoxic inhibition of insulin secretion and enhances glucose uptake into skeletal muscle cells. Thus, carnosine, or non-hydrolysable carnosine analogs, may represent a new class of therapeutic agent to fight type 2 diabetes
Mapping gene associations in human mitochondria using clinical disease phenotypes
Nuclear genes encode most mitochondrial proteins, and their mutations cause diverse and debilitating clinical disorders. To date, 1,200 of these mitochondrial genes have been recorded, while no standardized catalog exists of the associated clinical phenotypes. Such a catalog would be useful to develop methods to analyze human phenotypic data, to determine genotype-phenotype relations among many genes and diseases, and to support the clinical diagnosis of mitochondrial disorders. Here we establish a clinical phenotype catalog of 174 mitochondrial disease genes and study associations of diseases and genes. Phenotypic features such as clinical signs and symptoms were manually annotated from full-text medical articles and classified based on the hierarchical MeSH ontology. This classification of phenotypic features of each gene allowed for the comparison of diseases between different genes. In turn, we were then able to measure the phenotypic associations of disease genes for which we calculated a quantitative value that is based on their shared phenotypic features. The results showed that genes sharing more similar phenotypes have a stronger tendency for functional interactions, proving the usefulness of phenotype similarity values in disease gene network analysis. We then constructed a functional network of mitochondrial genes and discovered a higher connectivity for non-disease than for disease genes, and a tendency of disease genes to interact with each other. Utilizing these differences, we propose 168 candidate genes that resemble the characteristic interaction patterns of mitochondrial disease genes. Through their network associations, the candidates are further prioritized for the study of specific disorders such as optic neuropathies and Parkinson disease. Most mitochondrial disease phenotypes involve several clinical categories including neurologic, metabolic, and gastrointestinal disorders, which might indicate the effects of gene defects within the mitochondrial system. The accompanying knowledgebase (http://www.mitophenome.org/) supports the study of clinical diseases and associated genes
Extracellular Matrix Aggregates from Differentiating Embryoid Bodies as a Scaffold to Support ESC Proliferation and Differentiation
Embryonic stem cells (ESCs) have emerged as potential cell sources for tissue engineering and regeneration owing to its virtually unlimited replicative capacity and the potential to differentiate into a variety of cell types. Current differentiation strategies primarily involve various growth factor/inducer/repressor concoctions with less emphasis on the substrate. Developing biomaterials to promote stem cell proliferation and differentiation could aid in the realization of this goal. Extracellular matrix (ECM) components are important physiological regulators, and can provide cues to direct ESC expansion and differentiation. ECM undergoes constant remodeling with surrounding cells to accommodate specific developmental event. In this study, using ESC derived aggregates called embryoid bodies (EB) as a model, we characterized the biological nature of ECM in EB after exposure to different treatments: spontaneously differentiated and retinoic acid treated (denoted as SPT and RA, respectively). Next, we extracted this treatment-specific ECM by detergent decellularization methods (Triton X-100, DOC and SDS are compared). The resulting EB ECM scaffolds were seeded with undifferentiated ESCs using a novel cell seeding strategy, and the behavior of ESCs was studied. Our results showed that the optimized protocol efficiently removes cells while retaining crucial ECM and biochemical components. Decellularized ECM from SPT EB gave rise to a more favorable microenvironment for promoting ESC attachment, proliferation, and early differentiation, compared to native EB and decellularized ECM from RA EB. These findings suggest that various treatment conditions allow the formulation of unique ESC-ECM derived scaffolds to enhance ESC bioactivities, including proliferation and differentiation for tissue regeneration applications. © 2013 Goh et al
Why do women invest in pre-pregnancy health and care? A qualitative investigation with women attending maternity services
Background Despite the importance attributed to good pre-pregnancy care and its potential to improve pregnancy and child health outcomes, relatively little is known about why women invest in pre-pregnancy health and care. We sought to gain insight into why women invested in pre-pregnancy health and care. Methods We carried out 20 qualitative in-depth interviews with pregnant or recently pregnant women who were drawn from a survey of antenatal clinic attendees in London, UK. Interviewees were purposively sampled to include high and low investors in pre-pregnancy health and care, with variation in age, partnership status, ethnicity and pre-existing medical conditions. Data analysis was conducted using the Framework method. Results We identified three groups in relation to pre-pregnancy health and care: 1) The “prepared” group, who had high levels of pregnancy planning and mostly positive attitudes to micronutrient supplementation outside of pregnancy, carried out pre-pregnancy activities such as taking folic acid and making changes to diet and lifestyle. 2) The “poor knowledge” group, who also had high levels of pregnancy planning, did not carry out pre-pregnancy activities and described themselves as having poor knowledge. Elsewhere in their interviews they expressed a strong dislike of micronutrient supplementation. 3) The “absent pre-pregnancy period” group, had the lowest levels of pregnancy planning and also expressed anti-supplement views. Even discussing the pre-pregnancy period with this group was difficult as responses to questions quickly shifted to focus on pregnancy itself. Knowledge of folic acid was poor in all groups. Conclusion Different pre-pregnancy care approaches are likely to be needed for each of the groups. Among the “prepared” group, who were proactive and receptive to health messages, greater availability of information and better response from health professionals could improve the range of pre-pregnancy activities carried out. Among the “poor knowledge” group, better response from health professionals might yield greater uptake of pre-pregnancy information. A different, general health strategy might be more appropriate for the “absent pre-pregnancy period” group. The fact that general attitudes to micronutrient supplementation were closely related to whether or not women invested in pre-pregnancy health and care was an unanticipated finding and warrants further investigation.This report is independent research commissioned and funded by the Department of Health Policy Research Programme Pre-Pregnancy Health and Care in England: Exploring Implementation and Public Health Impact, 006/0068
Mechanisms controlling anaemia in Trypanosoma congolense infected mice.
Trypanosoma congolense are extracellular protozoan parasites of the blood stream of artiodactyls and are one of the main constraints on cattle production in Africa. In cattle, anaemia is the key feature of disease and persists after parasitaemia has declined to low or undetectable levels, but treatment to clear the parasites usually resolves the anaemia. The progress of anaemia after Trypanosoma congolense infection was followed in three mouse strains. Anaemia developed rapidly in all three strains until the peak of the first wave of parasitaemia. This was followed by a second phase, characterized by slower progress to severe anaemia in C57BL/6, by slow recovery in surviving A/J and a rapid recovery in BALB/c. There was no association between parasitaemia and severity of anaemia. Furthermore, functional T lymphocytes are not required for the induction of anaemia, since suppression of T cell activity with Cyclosporin A had neither an effect on the course of infection nor on anaemia. Expression of genes involved in erythropoiesis and iron metabolism was followed in spleen, liver and kidney tissues in the three strains of mice using microarrays. There was no evidence for a response to erythropoietin, consistent with anaemia of chronic disease, which is erythropoietin insensitive. However, the expression of transcription factors and genes involved in erythropoiesis and haemolysis did correlate with the expression of the inflammatory cytokines Il6 and Ifng. The innate immune response appears to be the major contributor to the inflammation associated with anaemia since suppression of T cells with CsA had no observable effect. Several transcription factors regulating haematopoiesis, Tal1, Gata1, Zfpm1 and Klf1 were expressed at consistently lower levels in C57BL/6 mice suggesting that these mice have a lower haematopoietic capacity and therefore less ability to recover from haemolysis induced anaemia after infection
The EQ-5D (Euroqol) is a valid generic instrument for measuring quality of life in patients with dyspepsia
<p>Abstract</p> <p>Background</p> <p>There is little information of the validity of generic instruments in measuring health-related quality of life (HRQOL) in patients with dyspepsia. We aimed to assess the reliability and validity of the EQ-5D, a brief and simple instrument, in measuring HRQOL in adult patients with dyspepsia.</p> <p>Methods</p> <p>Consecutive adults with dyspepsia attending the Gastroenterology clinic in a tertiary referral center were interviewed with the EQ-5D (both English and Malay versions), the short-form Nepean Dyspepsia Index (SF-NDI), the SF-36 and Leeds Dyspepsia Questionnaire (LDQ). Known-groups and convergent construct validity were investigated by testing hypotheses at attribute and overall levels. A repeat telephone interview was conducted 2 weeks later to assess test-retest reliability.</p> <p>Results</p> <p>A total of 113 patients (mean (SD) age: 53.7 (14) years; 49.5% male; 24.8% Malays, 37.2% Chinese; 70.8% functional dyspepsia) were recruited. Response rate was 100% with nil missing data. Known-groups validation revealed 20/26 hypotheses fulfillment. Patients with more severe dyspepsia reported more problems with their usual activity (p = 0.07) and pain (p = 0.06) and demonstrated lower median VAS scores (60 vs 70, p = 0.002) and EQ-5D utility scores (0.72 vs 0.78, p = 0.002). Those reporting problems in various EQ-5D dimensions had significantly lower scores in relevant SF-36 and SF-NDI dimensions. The overall EQ-5D utility score also demonstrated good correlation with the SF-36 summary physical and mental scores and the SF-NDI total score. Intraclass correlation coefficient for test-retest reliability was 0.66 (95% CI = 0.55 – 0.76).</p> <p>Conclusion</p> <p>The EQ-5D is an acceptable, valid and reliable generic instrument for measuring HRQOL in adult patients with dyspepsia.</p
Excision of sympathetic ganglia and the rami communicantes with histological confirmation offers better early and late outcomes in Video assisted thoracoscopic sympathectomy
<p>Abstract</p> <p>Background</p> <p>Video-Assisted Thoracoscopic Sympathectomy (VATS) is an established minimally invasive procedure for thoracic sympathetic blockade in patients with hyperhidrosis, facial flushing and intractable angina. Various techniques using clips, diathermy and excision are used to perform sympathectomy. We present our technique of excision of the sympathetic chain with histological proof and the analysis of the early and late outcomes.</p> <p>Methods</p> <p>We evaluated 200 procedures in 100 consecutive patients, who underwent Video Assisted Thoracoscopic Sympathectomy by a single surgeon in our centre between September 1996 to March 2007. All patients had maximum medical therapy prior to surgery and were divided into 3 groups based on indications, Group 1(hyperhidrosis: 48 patients), Group 2 (facial flushing: 26 patients) and Group 3(intractable angina: 26 patients). The demography and severity of symptoms for each group were analysed. The endpoints were success rate, 30 day mortality, complications and patient's satisfaction.</p> <p>Results</p> <p>99 patients had bilateral VATS sympathectomy and 1 had unilateral sympathectomy. The conversion rate to open was 1(1%). All patients had successful removal of ganglia proven histologically with no perioperative mortality in our series. The complications included pneumothorax (5%), acute coronary syndrome (2%), transient Horner's syndrome (1%), transient paraesthesia (1%), wound infection (4%), compensatory hyperhidrosis (18%), residual flushing (3%) and wound pain (5%). There were five late deaths in the intractable angina group at a mean follow up of 36.7 months. Overall success rates of abolishing the symptoms were 96.3%, 87.5% and 95.2% for Group 1, 2 and 3 respectively.</p> <p>Conclusion</p> <p>Excision of the sympathetic chain with histological confirmation during VATS sympathectomy is a safe and effective method in treating hyperhidrosis, facial flushing and intractable angina with good long term results and satisfaction.</p
Carbon dioxide fluxes across the Sierra de Guadarrama, Spain
Understanding the spatial and temporal variation in soil respiration within small geographic areas is essential to accurately assess the carbon budget on a global scale. In this study, we investigated the factors controlling soil respiration in an altitudinal gradient in a southern Mediterranean mixed pine–oak forest ecosystem in the north face of the Sierra de Guadarrama in Spain. Soil respiration was measured in five Pinus sylvestris L. plots over a period of 1 year by means of a closed dynamic system (LI-COR 6400). Soil temperature and water content were measured at the same time as soil respiration. Other soil physico-chemical and microbiological properties were measured during the study. Measured soil respiration ranged from 6.8 to 1.4 lmol m-2 s-1, showing the highest values at plots situated at higher elevation. Q10 values ranged between 1.30 and 2.04, while R10 values ranged between 2.0 and 3.6. The results indicate that the seasonal variation of soil respiration was mainly controlled by soil temperature and moisture. Among sites, soil carbon and nitrogen stocks regulate soil respiration in addition to soil temperature and moisture. Our results suggest that application of standard models to estimate soil respiration for small geographic areas may not be adequate unless other factors are considered in addition to soil temperature
Persistent orocutaneous and anal fistulae induced by nicorandil: a case report
<p>Abstract</p> <p>Introduction</p> <p>Although nicorandil is prescribed widely, awareness of its potential to cause serious complications to the gastrointestinal tract mucosa is limited. Whilst nicorandil-induced oral and anal ulceration is well documented in the literature, nicorandil-induced fistulation is not. This is the first report in the literature of a single patient demonstrating simultaneous orocutaneous and anal fistulae during nicorandil therapy. Two separate cases of orocutaneous and anal fistulae associated nicorandil usage have previously been documented in specialist journals.</p> <p>Case presentation</p> <p>A 71-year-old Caucasian man presented with a 3-year history of concurrent orocutaneous and anal fistulae. He had been exposed to 30 mg twice-daily nicorandil therapy for 4 years. Both fistulae responded poorly to intensive and prolonged conventional treatment but healed promptly on reduction and eventual withdrawal of nicorandil therapy.</p> <p>Conclusion</p> <p>Management of resistant cases of orocutaneous and anal fistulae in patients on high-dose nicorandil therapy may be impossible without reduction or even withdrawal of nicorandil.</p
CEO Profile and Earnings Quality
This paper introduces the PSCORE, which aggregates nine personal characteristics of chief executive officers (CEOs), to signal the quality of earnings. The PSCORE is a composite score based on publicly available data on CEOs. The study reports strong positive relationships between the PSCORE and two different proxies for earnings quality, (i) discretionary accruals and (ii) financial statement errors, measured by deviations of the first digits of figures reported in financial statements from those expected by Benford’s Law. Further analyses indicate that the relationships between the PSCORE and the proxies for earnings quality become more pronounced when CEOs have high equity-based compensation incentives. The findings have some implications for practitioners
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