511 research outputs found

    Hypertonicity-induced cation channels rescue cells from staurosporine-elicited apoptosis

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    Cell shrinkage is one of the earliest events during apoptosis. Cell shrinkage also occurs upon hypertonic stress, and previous work has shown that hypertonicity-induced cation channels (HICCs) underlie a highly efficient mechanism of recovery from cell shrinkage, called the regulatory volume increase (RVI), in many cell types. Here, the effects of HICC activation on staurosporine-induced apoptotic volume decrease (AVD) and apoptosis were studied in HeLa cells by means of electronic cell sizing and whole-cell patch-clamp recording. It was found that hypertonic stress reduces staurosporine-induced AVD and cell death (associated with caspase-3/7 activation and DNA fragmentation), and that this effect was actually due to activation of the HICC. On the other hand, staurosporine was found to significantly reduce osmotic HICC activation. It is concluded that AVD and RVI reflect two fundamentally distinct functional modes in terms of the activity and role of the HICC, in a shrunken cell. Our results also demonstrate, for the first time, the ability of the HICC to rescue cells from the process of programmed cell death

    The calcium-Activated potassium channel KCa3.1 is an important modulator of hepatic injury

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    The calcium-Activated potassium channel KCa3.1 controls different cellular processes such as proliferation and volume homeostasis. We investigated the role of KCa3.1 in experimental and human liver fibrosis. KCa3.1 gene expression was investigated in healthy and injured human and rodent liver. Effect of genetic depletion and pharmacological inhibition of KCa3.1 was evaluated in mice during carbon tetrachloride induced hepatic fibrogenesis. Transcription, protein expression and localisation of KCa3.1 was analysed by reverse transcription polymerase chain reaction, Western blot and immunohistochemistry. Hemodynamic effects of KCa3.1 inhibition were investigated in bile duct-ligated and carbon tetrachloride intoxicated rats. In vitro experiments were performed in rat hepatic stellate cells and hepatocytes. KCa3.1 expression was increased in rodent and human liver fibrosis and was predominantly observed in the hepatocytes. Inhibition of KCa3.1 aggravated liver fibrosis during carbon tetrachloride challenge but did not change hemodynamic parameters in portal hypertensive rats. In vitro, KCa3.1 inhibition leads to increased hepatocyte apoptosis and DNA damage, whereas proliferation of hepatic stellate cells was stimulated by KCa3.1 inhibition. Our data identifies KCa3.1 channels as important modulators in hepatocellular homeostasis. In contrast to previous studies in vitro and other tissues this channel appears to be anti-fibrotic and protective during liver injury

    Mechanisms of tauroursodeoxycholate-mediated inhibition of apoptosis

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    Uvas de mesa produzidas sob cobertura plástica na Serra Gaúcha.

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    XV Congresso Latino-Americano de Viticultura e Enologia E XIII Congresso Brasileiro de Viticultura e Enologia. Bento Gonçalves-RS, 3 a 7 de Novembro de 2015

    Avaliação de atributos físico-químicos e sensoriais de sucos de uva elaborados com nove cultivares de uva.

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    XV Congresso Latino-Americano de Viticultura e Enologia E XIII Congresso Brasileiro de Viticultura e Enologia. Bento Gonçalves-RS, 3 a 7 de Novembro de 2015

    Genetic Markers of Obesity Risk: Stronger Associations with Body Composition in Overweight Compared to Normal-Weight Children

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    Genetic factors are important determinants of overweight. We examined whether there are differential effect sizes depending on children's body composition. We analysed data of n = 4,837 children recorded in the Avon Longitudinal Study of Parents and Children (ALSPAC), applying quantile regression with sex- and age-specific standard deviation scores (SDS) of body mass index (BMI) or with body fat mass index and fat-free mass index at 9 years as outcome variables and an "obesity-risk-allele score" based on eight genetic variants known to be associated with childhood BMI as the explanatory variable. The quantile regression coefficients increased with increasing child's BMI-SDS and fat mass index percentiles, indicating larger effects of the genetic factors at higher percentiles. While the associations with BMI-SDS were of similar size in medium and high BMI quantiles (40th percentile and above), effect sizes with fat mass index increased over the whole fat mass index distribution. For example, the fat mass index of a normal-weight (50th percentile) child was increased by 0.13 kg/m(2) (95% confidence interval (CI): 0.09, 0.16) per additional allele, compared to 0.24 kg/m(2) per allele (95% CI: 0.15, 0.32) in children at the 90th percentile. The genetic associations with fat-free mass index were weaker and the quantile regression effects less pronounced than those on fat mass index. Genetic risk factors for childhood overweight appear to have greater effects on fatter children. Interaction of known genetic factors with environmental or unknown genetic factors might provide a potential explanation of these findings

    Attitudes towards sex workers: a nationwide cross-sectional survey among German healthcare providers

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    BackgroundWorldwide, sex workers face stigmatization and discrimination, also within healthcare. Only few studies on healthcare providers’ attitudes towards care of sex workers have been performed. This study assessed attitudes and knowledge of healthcare providers in Germany towards sex workers and their specific health risks.MethodsGerman healthcare professionals and medical students were invited to participate in a nationwide cross-sectional study in 2022. The online survey used a German translation of the “Attitudes towards Prostitutes and Prostitution Scale” by Levin and Peled for assessment of attitudes towards sex work and workers, together with prevalence estimates of common mental and physical disorders.ResultsA total of 469 questionnaires were included into analysis. Older participants tended to regard sex work as less of a choice (p < 0.004) and sex workers as more victimized (p < 0.001). The frequency of professional contact to sex workers neither affected the perception of sex workers’ status as victims vs. independent individuals, nor the perceived moral status. Moreover, healthcare professionals overestimated the prevalence of various disorders which was influenced by participants’ attitudes towards sex workers.DiscussionA comparison to a recent Allensbach survey demonstrated similar attitudes of healthcare providers and the general population towards sex workers. Our results suggest that German healthcare professionals are not free of prejudices against sex workers, as has been shown for other marginalized groups in society. Instead, they seem to be influenced by personal opinion rather than by objective facts which they should have acquired during their professional education. Future interventions (e.g., better training regarding marginal societal groups) are necessary to encounter these issues in order to improve healthcare for sex workers
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