423 research outputs found

    Resistance of R-Ras knockout mice to skin tumour induction

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    The R-ras gene encodes a small GTPase that is a member of the Ras family. Despite close sequence similarities, R-Ras is functionally distinct from the prototypic Ras proteins; no transformative activity and no activating mutations of R-Ras in human malignancies have been reported for it. R-Ras activity appears inhibitory towards tumour proliferation and invasion, and to promote cellular quiescence. Contrary to this, using mice with a deletion of the R-ras gene, we found that R-Ras facilitates DMBA/TPA-induced skin tumour induction. The tumours appeared in wild-type (WT) mice on average 6 weeks earlier than in R-Ras knockout (R-Ras KO) mice. WT mice developed almost 6 times more tumours than R-Ras KO mice. Despite strong R-Ras protein expression in the dermal blood vessels, no R-Ras could be detected in the epidermis from where the tumours arose. The DMBA/TPA skin tumourigenesis-model is highly dependent upon inflammation, and we found a greatly attenuated skin inflammatory response to DMBA/TPA-treatment in the R-Ras KO mice in the context of leukocyte infiltration and proinflammatory cytokine expression. Thus, these data suggest that despite its characterised role in promoting cellular quiescence, R-Ras is pro-tumourigenic in the DMBA/TPA tumour model and important for the inflammatory response to DMBA/TPA treatment

    Needs assessment to strengthen capacity in water and sanitation research in Africa:experiences of the African SNOWS consortium

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    Despite its contribution to global disease burden, diarrhoeal disease is still a relatively neglected area for research funding, especially in low-income country settings. The SNOWS consortium (Scientists Networked for Outcomes from Water and Sanitation) is funded by the Wellcome Trust under an initiative to build the necessary research skills in Africa. This paper focuses on the research training needs of the consortium as identified during the first three years of the project

    Toward a Unified Genetic Map of Higher Plants, Transcending the Monocot-Dicot Divergence

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    Closely related (confamilial) genera often retain large chromosomal tracts in which gene order is colinear, punctuated by structural mutations such as inversions and translocations 1. To explore the possibility that conservation of gene order might extrapolate to more distantly related taxa, we first estimated an average structural mutation rate. Nine pairs of taxa, for which there exist both comparative genetic maps and plausible estimates of divergence time, showed an average of0.14 (±0.06) structural mutations per chromosome per million years of divergence (Myr; Table 1). This value is offered as a first approximation, acknowledging that refined comparative data and/or divergence estimates may impel revision

    The diagnosis and treatment of primary biliary cirrhosis

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    Primary biliary cirrhosis (PBC) is a slowly progressive cholestatic liver disease of autoimmune etiology. The initial presentation of PBC is various from asymptomatic, abnormal liver biochemical tests to overt cirrhosis. The diagnosis of PBC is based on cholestatic biochemical liver tests, presence of antimitochondrial antibody and histologic findings of nonsuppurative destructive cholangitis. Although the diagnosis is straightforward, it could be underdiagnosed because of its asymptomatic presentation, or underrecognition of the disease. UDCA in a dose of 13-15 mg/kg is the widely approved therapy which can improve the prognosis of patients with PBC. However, one-third of patients does not respond to UDCA therapy and may require liver transplantation. Every effort to diagnose PBC in earlier stage and to develop new therapeutic drugs and clinical trials should be made

    Pharmacokinetics of Two Common Antiretroviral Regimens in Older HIV-Infected Patients: A Pilot Study

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    The pharmacokinetics (PK) of antiretrovirals (ARVs) in older HIV-infected patients are poorly described. Here, the steady-state PK of 2 common ARV regimens (tenofovir [TFV]/emtricitabine [FTC]/efavirenz [EFV]; TFV/FTC/atazanavir [ATV]/ritonavir [RTV]) in older non-frail HIV-infected patients are presented

    No Association between Fish Intake and Depression in over 15,000 Older Adults from Seven Low and Middle Income Countries–The 10/66 Study

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    Background: Evidence on the association between fish consumption and depression is inconsistent and virtually nonexistent from low-and middle-income countries. Using a standard protocol, we aim to assess the association of fish consumption and late-life depression in seven low-and middle-income countries. Methodology/Findings: We used cross-sectional data from the 10/66 cohort study and applied two diagnostic criteria for late-life depression to assess the association between categories of weekly fish consumption and depression according to ICD-10 and the EURO-D depression symptoms scale scores, adjusting for relevant confounders. All-catchment area surveys were carried out in Cuba, Dominican Republic, Venezuela, Peru, Mexico, China, and India, and over 15,000 community-dwelling older adults (65+) were sampled. Using Poisson models the adjusted association between categories of fish consumption and ICD-10 depression was positive in India (p for trend = 0.001), inverse in Peru (p = 0.025), and not significant in all other countries. We found a linear inverse association between fish consumption categories and EURO-D scores only in Cuba (p for trend = 0.039) and China (p<0.001); associations were not significant in all other countries. Between-country heterogeneity was marked for both ICD-10 (I-2>61%) and EURO-D criteria (I-2>66%). Conclusions: The associations of fish consumption with depression in large samples of older adults varied markedly across countries and by depression diagnosis and were explained by socio-demographic and lifestyle variables. Experimental studies in these settings are needed to confirm our findings.Multidisciplinary SciencesSCI(E)SSCI0ARTICLE6null

    Co-designing inflammatory bowel disease (Ibd) services in Scotland : findings from a nationwide survey

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    Background: The Scottish Government’s ambition is to ensure that health services are co-designed with the communities they serve. Crohn’s and Colitis UK and the Scottish Government acknowledged the need to review and update the current IBD care model. An online survey was conducted asking IBD patients about their experiences of the NHS care they receive. This survey was the first step of co-designing and developing a national strategy for IBD service improvement in Scotland. Aim: To explore IBD patients’ experiences of current services and make recommendations for future service development. Methods: This study was part of a wider cross-sectional on-line survey. Participants were patients with IBD across Scotland. 777 people with IBD took part in the survey. Thematic analysis of all data was conducted independently by two researchers. Results: Three key themes emerged: Quality of life: Participants highlighted the impact the disease has on quality of life and the desperate need for IBD services to address this more holistically. IBD clinicians and access: Participants recognised the need for more IBD nurses and gastroenterologists along with better access to them. Those with a named IBD nurse reported to be more satisfied with their care. An explicit IBD care pathway: Patients with IBD identified the need of making the IBD care pathway more explicit to service users. Conclusions: Participants expressed the need for a more holistic approach to their IBD care. This includes integrating psychological, counselling and dietetic services into IBD care with better access to IBD clinicians and a more explicit IBD care pathway. Keywords: Inflammatory bowel disease, Co-designing, Qualitative study, Patient survey, Crohn’s disease, Ulcerative coliti

    A retrospective analysis of noise-induced hearing loss in the Dutch construction industry

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    Purpose Noise exposure is an important and highly prevalent occupational hazard in the construction industry. This study examines hearing threshold levels of a large population of Dutch construction workers and compares their hearing thresholds to those predicted by ISO-1999. Methods In this retrospective study, medical records of periodic occupational health examinations of 29,644 construction workers are analysed. Pure-tone audiometric thresholds of noise-exposed workers are compared to a non-exposed control group and to ISO-1999 predictions. Regression analyses are conducted to explore the relationship between hearing loss and noise intensity, noise exposure time and the use of hearing protection. Results Noise-exposed workers had greater hearing losses compared to their non-noise-exposed colleagues and to the reference population reported in ISO-1999. Noise exposure explained only a small proportion of hearing loss. When the daily noise exposure level rose from 80 dB(A) towards 96 dB(A), only a minor increase in hearing loss is shown. The relation of exposure time and hearing loss found was similar to ISO-1999 predictions when looking at durations of 10 years or more. For the first decade, the population medians show poorer hearing than predicted by ISO-1999. Discussion Duration of noise exposure was a better predictor than noise exposure levels, probably because of the limitations in noise exposure estimations. In this population, noise-induced hearing loss was already present at the beginning of employment and increased at the same rate as is predicted for longer exposure duration

    Altered Arterial Stiffness and Subendocardial Viability Ratio in Young Healthy Light Smokers after Acute Exercise

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    Studies showed that long-standing smokers have stiffer arteries at rest. However, the effect of smoking on the ability of the vascular system to respond to increased demands (physical stress) has not been studied. The purpose of this study was to estimate the effect of smoking on arterial stiffness and subendocardial viability ratio, at rest and after acute exercise in young healthy individuals.Healthy light smokers (n = 24, pack-years = 2.9) and non-smokers (n = 53) underwent pulse wave analysis and carotid-femoral pulse wave velocity measurements at rest, and 2, 5, 10, and 15 minutes following an exercise test to exhaustion. Smokers were tested, 1) after 12h abstinence from smoking (chronic condition) and 2) immediately after smoking one cigarette (acute condition). At rest, chronic smokers had higher augmentation index and lower aortic pulse pressure than non-smokers, while subendocardial viability ratio was not significantly different. Acute smoking increased resting augmentation index and decreased subendocardial viability ratio compared with non-smokers, and decreased subendocardial viability ratio compared with the chronic condition. After exercise, subendocardial viability ratio was lower, and augmentation index and aortic pulse pressure were higher in non-smokers than smokers in the chronic and acute conditions. cfPWV rate of recovery of was greater in non-smokers than chronic smokers after exercise. Non-smokers were also able to achieve higher workloads than smokers in both conditions.Chronic and acute smoking appears to diminish the vascular response to physical stress. This can be seen as an impaired 'vascular reserve' or a blunted ability of the blood vessels to accommodate the changes required to achieve higher workloads. These changes were noted before changes in arterial stiffness or subendocardial viability ratio occurred at rest. Even light smoking in young healthy individuals appears to have harmful effects on vascular function, affecting the ability of the vascular bed to respond to increased demands
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