34 research outputs found

    Aryltetralin lignans from Hyptis brachiata inhibiting T lymphocyte proliferation

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    Increased activation and proliferation of T lymphocytes plays an essential role in the development of chronic inflammation and autoimmune diseases. Currently used immunosuppressive drugs often do not provide long-lasting relief of symptoms and show a gradual loss of efficacy over time, and are accompanied by various side effects. Therefore, novel immunosuppressive lead substances are needed. For this purpose, an in-house library consisting of 600 extracts of plants from Panama was screened for inhibition of human T lymphocyte proliferation. As one of the hits, an ethyl acetate extract from the aerial parts of Hyptis brachiata (Lamiaceae) exhibited strong inhibitory effects. Subsequent investigation resulted in the isolation of seven aryltetralin lignans, five arylnaphthalene lignans, two flavonoids, three triterpenes, and cinnamyl cinnamate. Aryltetralin lignans inhibited T lymphocyte proliferation in a concentration-dependent manner without induction of apoptosis. No relevant inhibition was observed for the arylnaphthalene lignans, flavonoids, and triterpenes. Additional cell cycle arrest investigations revealed that isolated aryltetralin lignans potently inhibited cell division in G2/M phase similarly to podophyllotoxin. Multifluorescence panel analyses of the extract also showed weak suppressive effects on the production of IL-2 and TNF-α. Therefore, preparations made out of H. brachiata could be further explored as an interesting herbal alternative in the treatment of autoimmune diseases

    Pre-ischemic Lactate Levels Affect the Post-ischemic Recovery in an Isolated Rat Heart Model of Donation After Circulatory Death (DCD)

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    Introduction: Donation after circulatory death (DCD) could substantially improve donor heart availability. In DCD, the heart is not only exposed to a period of warm ischemia, but also to a damaging pre-ischemic phase. We hypothesized that the DCD-relevant pre-ischemic lactate levels negatively affect the post-ischemic functional and mitochondrial recovery in an isolated rat heart model of DCD. Methods: Isolated, working rat hearts underwent 28.5′ of global ischemia and 60′ of reperfusion. Prior to ischemia, hearts were perfused with one of three pre-ischemic lactate levels: no lactate (0 Lac), physiologic lactate (0.5 mM; 0.5 Lac), or DCD-relevant lactate (1 mM; 1 Lac). In a fourth group, an inhibitor of the mitochondrial calcium uniporter was added in reperfusion to 1 Lac hearts (1 Lac + Ru360). Results: During reperfusion, left ventricular work (heart rate-developed pressure product) was significantly greater in 0.5 Lac hearts compared to 0 Lac or 1 Lac. In 1 vs. 0.5 Lac hearts, in parallel with a decreased function, cellular and mitochondrial damage was greater, tissue calcium content tended to increase, while oxidative stress damage tended to decrease. The addition of Ru360 to 1 Lac hearts partially abrogated the negative effects of the DCD-relevant pre-ischemic lactate levels (greater post-ischemic left ventricular work and less cytochrome c release in 1 Lac+Ru360 vs. 1 Lac). Conclusion: DCD-relevant levels of pre-ischemic lactate (1 mM) reduce contractile, cellular, and mitochondrial recovery during reperfusion compared to physiologic lactate levels. Inhibition of mitochondrial calcium uptake during early reperfusion improves the post-ischemic recovery of 1 Lac hearts, indicating calcium overload as a potential therapeutic reperfusion target for DCD hearts

    Heightened NLRP3 inflammasome activation is associated with aging and CMML diseases severity

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    Aging causes chronic low-grade inflammation known as inflamm-aging. It is a risk factor for chronic myelomonocytic leukemia (CMML), a hematological malignancy that is most prevalent in older people. Recent studies suggest a critical role for the NLRP3 inflammasome in inflamm-aging. However, the mechanisms involved in NLRP3 activation in aging and its involvement in CMML progression are not fully understood. Here, we report that aging increases interleukin-1β production upon NLRP3 activation in human CD14+ monocytes. Interestingly, we found that Toll-like receptor (TLR) 1/2 agonist Pam3Cysk4 directly activates NLRP3 inflammasome without the requirement of second activation signal in monocytes from older but not from younger healthy donors. Further, we observed a dichotomous response to NLRP3 inflammasome activation in monocytes from CMML patients. Intriguingly, CMML patients with heightened NLRP3 activation showed increased treatment dependency and disease severity. Collectively, our results suggest that aging causes increased sensitivity to NLRP3 inflammasome activation at cellular level, which may explain increased inflammation and immune dysregulation in older individuals. Furthermore, NLRP3 inflammasome activation was dysregulated in CMML and positively correlated with disease severity

    Photometric determination of the mass accretion rates of pre-main sequence stars. II. NGC346 in the Small Magellanic Cloud

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    [Abridged] We have studied the properties of the stellar populations in the field of the NGC346 cluster in the Small Magellanic Cloud, using a novel self-consistent method that allows us to reliably identify pre-main sequence (PMS) objects actively undergoing mass accretion, regardless of their age. The method does not require spectroscopy and combines broad-band V and I photometry with narrow-band Halpha imaging to identify all stars with excess Halpha emission and derive the accretion luminosity Lacc and mass accretion rate Macc for all of them. The application of this method to existing HST/ACS photometry of the NGC346 field has allowed us to identify and study 680 bona-fide PMS stars with masses from ~0.4 to ~4 Msolar and ages in the range from ~1 to ~30 Myr. This is the first study to reveal that, besides a young population of PMS stars (~ 1 Myr old), in this field there is also an older population of PMS objects with a median age of ~20 Myr. We provide for all of them accurate physical parameters. We study the evolution of the mass accretion rate as a function of stellar parameters and find that logMacc ~ -0.6 Log t + Log m + c, where t is the age of the star, m its mass and c a quantity that is higher at lower metallicity. The high mass accretion rates that we find suggest that a considerable fraction of the stellar mass is accreted during the PMS phase and that PMS evolutionary models that do not account for this effect will systematically underestimate the true age when compared with the observations.Comment: Accepted for publication in the ApJ. 14 pages, 11 figures. Corrected typos and reference

    Factually Consistent Summarization via Reinforcement Learning with Textual Entailment Feedback

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    Despite the seeming success of contemporary grounded text generation systems, they often tend to generate factually inconsistent text with respect to their input. This phenomenon is emphasized in tasks like summarization, in which the generated summaries should be corroborated by their source article. In this work, we leverage recent progress on textual entailment models to directly address this problem for abstractive summarization systems. We use reinforcement learning with reference-free, textual entailment rewards to optimize for factual consistency and explore the ensuing trade-offs, as improved consistency may come at the cost of less informative or more extractive summaries. Our results, according to both automatic metrics and human evaluation, show that our method considerably improves the faithfulness, salience, and conciseness of the generated summaries.Comment: ACL 202

    SAPALDIA: Methods and participation in the cross-sectional part of the Swiss Study on Air Pollution and Lung Diseases in Adults

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    Summary: SAPALDIA-the Swiss Study on Air Pollution and Lung Diseases in Adults-focuses on the long term health effects of low to moderate levels of air pollutants as typically seen in different parts of Switzerland. The aim of the SAPALDIA cross-sectional study carried out in 1991 was to determine the prevalence of bronchial asthma, chronic bronchitis and allergic conditions in the adult population of Switzerland and to identify and to determine the respective importance of potentially influencing factors. These could be both personal (smoking habits, allergy status, family history, occupation) and environmental (outdoor and indoor pollution, aeroallergens, climate). A further aim of the cross-sectional study consisted in the identification of individuals susceptible to present symptoms during a two year observation period and to be included in the SAPALDIA follow-up study. This technical report represents the methodological documentation for the cross-sectional study of SAPALDIA. The instruments and the methods of standardisation are presented and discussed. The medical examination consisted of a computerised interview using a standardised questionnaire, the taking of a blood sample for serological tests, allergy skin testing, the measurement of endexpiratory CO and body height, and pulmonary function testing followed by methacholine challenge testing or bronchodilatation testing. The pattern of participation and the 9651 participants of the study, representing 59.3% of the sample, are described. Based on information on non-participants gained by telephone interviews and mailed short questionnaires, possible selection biases are quantified and discusse

    Follow-up of the Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA 2) 1991-2003: methods and characterization of participants

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    Summary.: Objectives: The Swiss Cohort Study on Air Pollution and Lung Diseases in Adults (SAPALDIA) was designed to investigate the health effects from long-term exposure to air pollution. Methods: The health assessment at recruitment (1991) and at the first reassessment (2001-3) consisted of an interview about respiratory health, occupational and other exposures, spirometry, a methacholine bronchial challenge test, end-expiratory carbon monoxide (CO) measurement and measurement for atopy. A bio bank for DNA and blood markers was established. Heart rate variability was measured using a 24-hour ECG (Holter) in a random sample of participants aged 50years and older. Concentrations of nitrogen dioxide (NO2), sulphur dioxide (SO2), ozone (O3) and particulates in ambient air have been monitored in all study areas since 1991. Residential histories collected over the 11year follow-up period coupled with GIS modelling will provide individual long-term air pollutant exposure estimates. Results: Of 9651 participants examined in 1991, 8715 could be traced for the cohort study and 283 died. Basic information about health status was obtained for 8047 individuals (86% of alive persons), 6528 individuals (70%) agreed to the health examination and 5973 subjects (62%) completed the entire protocol. Non-participants in the reassessment were on average younger than participants and more likely to have been smokers and to have reported respiratory symptoms in the first assessment. Average weight had increased by 5.5kg in 11years and 28% of smokers in 1991 had quit by the time of the reassessmen

    How to conceptualize and implement a PhD program in health sciences - the Basel approach

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    Over the past decade, several excellent guidelines have been published on how to enhance the quality of PhD education in Europe. Aimed primarily at preparing students for innovative roles in their fields, they include variously structured approaches to curricular offerings, as well as other program components applicable across specialties (eg: supervisor support, scientific conduct, transferable skills). Since 2012, the interdisciplinary PhD Program in Health Sciences (PPHS) at the Faculty of Medicine of the University of Basel in Switzerland has focused on translating these guidelines into a 21st-century health sciences PhD program.; The PPHS started in 2012 based on the European Union (EU) guidelines for PhD education. This article describes the resulting interdisciplinary PhD program's conceptual underpinnings, rationale, structures, and 10 building blocks, like student portfolios, thematic training, interdisciplinary research seminars, student-initiated interdisciplinary activities, financial support of course participation, top-up and extension stipends, PhD supervision, research integrity, alumni follow-up network, and promotional tools including a dedicated website. Students enter from Clinical Research, Medicine Development, Nursing Science, Epidemiology and Public Health including Insurance Medicine, Sport Science (all from the Faculty of Medicine), and Epidemiology (Faculty of Science).; The Basel PPHS exemplifies state-of-the-art PhD education in Health Sciences based on European guidelines and offers guidance to other groups from conceptualization to rollout of an interdisciplinary health sciences PhD program
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