86 research outputs found

    A Microphysiological System for Studying Nonalcoholic Steatohepatitis

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    Nonalcoholic steatohepatitis (NASH) is the most severe form of nonalcoholic fatty liver disease (NAFLD), which to date has no approved drug treatments. There is an urgent need for better understanding of the genetic and molecular pathways that underlie NAFLD/NASH, and currently available preclinical models, be they in vivo or in vitro, do not fully represent key aspects of the human disease state. We have developed a human in vitro co‐culture NASH model using primary human hepatocytes, Kupffer cells and hepatic stellate cells, which are cultured together as microtissues in a perfused three‐dimensional microphysiological system (MPS). The microtissues were cultured in medium containing free fatty acids for at least 2 weeks, to induce a NASH‐like phenotype. The co‐culture microtissues within the MPS display a NASH‐like phenotype, showing key features of the disease including hepatic fat accumulation, the production of an inflammatory milieu, and the expression of profibrotic markers. Addition of lipopolysaccharide resulted in a more pro‐inflammatory milieu. In the model, obeticholic acid ameliorated the NASH phenotype. Microtissues were formed from both wild‐type and patatin‐like phospholipase domain containing 3 (PNPLA3) I148M mutant hepatic stellate cells. Stellate cells carrying the mutation enhanced the overall disease state of the model and in particular produced a more pro‐inflammatory milieu. Conclusion: The MPS model displays a phenotype akin to advanced NAFLD or NASH and has utility as a tool for exploring mechanisms underlying the disease. Furthermore, we demonstrate that in co‐culture the PNPLA3 I148M mutation alone can cause hepatic stellate cells to enhance the overall NASH disease phenotype

    Transmission patterns of smallpox: systematic review of natural outbreaks in Europe and North America since World War II

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    BACKGROUND: Because smallpox (variola major) may be used as a biological weapon, we reviewed outbreaks in post-World War II Europe and North America in order to understand smallpox transmission patterns. METHODS: A systematic review was used to identify papers from the National Library of Medicine, Embase, Biosis, Cochrane Library, Defense Technical Information Center, WorldCat, and reference lists of included publications. Two authors reviewed selected papers for smallpox outbreaks. RESULTS: 51 relevant outbreaks were identified from 1,389 publications. The median for the effective first generation reproduction rate (initial R) was 2 (range 0–38). The majority outbreaks were small (less than 5 cases) and contained within one generation. Outbreaks with few hospitalized patients had low initial R values (median of 1) and were prolonged if not initially recognized (median of 3 generations); outbreaks with mostly hospitalized patients had higher initial R values (median 12) and were shorter (median of 3 generations). Index cases with an atypical presentation of smallpox were less likely to have been diagnosed with smallpox; outbreaks in which the index case was not correctly diagnosed were larger (median of 27.5 cases) and longer (median of 3 generations) compared to outbreaks in which the index case was correctly diagnosed (median of 3 cases and 1 generation). CONCLUSION: Patterns of spread during Smallpox outbreaks varied with circumstances, but early detection and implementation of control measures is a most important influence on the magnitude of outbreaks. The majority of outbreaks studied in Europe and North America were controlled within a few generations if detected early

    Technological conditions of intermodal transhipment terminals in Poland

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    The following paper introduces comparison and evaluation of two intermodal transport technologies. The first of them is “rolling motorway” technology, better known as “Rollende Landstrasse” or ”Ro–La”, while the second one is called pocket wagons technology. We present general characteristics of chosen intermodal freight transport technologies in a form of a brief description of both intermodal technologies. Moreover, we describe initial processes, loading and operations in the case of the two mentioned technologies. The paper contains as well as computing example and the schemes of intermodal freight transhipments terminals for “rolling motorway” and pocket wagons technologies and inevitably means of transport to be used in the technologies. The chosen wagon types taken into consideration are as it follows. In case of “Rollende Landstrasse” technology we chose wagon types of 602S, Saadkkms and Saadkms and in case of the second technology the chosen types of wagons are: Sdggmrss, Sdgnss and Sdgmnss. Different kind of wagons in mentioned technologies are pictured and briefly described. Additionally, freight wagons – potentially used in the mentioned technologies – are evaluated with use of selected methods applicable in evaluation of alternatives. Wagons are evaluated under the specified conditions, especially with taking into consideration chosen operational parameters of them. In conclusion we relate to current condition of internal transhipment terminals in Poland and other aspects that concern them

    Badania geomorfologiczne w Polsce : aktualny stan i perspektywy

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