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A promising way to oppose infectious challenges would be to improve the resistance of the target species through genetic selection. Theoretically, a candidate gene is available against influenza viruses since a resistance trait was fortuitously discovered in the A2G mouse strain. This trait was demonstrated to be correlated with the expression of a specific isoform of the type I interferon (IFN)-dependent protein MX, an isoform coded by a specific allele at the mouse Mx1 locus. Two allelic polymorphisms were described recently in the Sus scrofa homologous gene. In this study, the frequencies and distribution of both alleles were evaluated among European domestic pig and wild boar populations by PCR-RFLP, and the anti-influenza activity conferred by both MX1 isoforms was evaluated in vitro using transfection of Vero cells followed by flow cytometric determination of the fraction of influenza virus-infected cells among MX-producing and MX-nonproducing cell populations. A significant difference in the anti-influenza activity brought by the two MX1 isoforms was demonstrated, which suggests that a significant improvement of innate resistance of pigs by genetic selection might be feasible provided the differences found here in vitro are epidemiologically relevant in vivo.  相似文献   
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Prolactin concentration was measured 20 minutes after each seizure in 8 patients with grand mal, 2 patients with complex partial seizures and 5 patients with petit mal seizures. In the group of grand mal and complex partial seizures serum prolactin showed markedly increased levels. After petit mal seizures there was no change in serum prolactin concentration. The possible causes for changes in serum prolactin after a seizure in children are discussed.  相似文献   
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The influence of basic reaction parameters—the ratio of catalyst components, the composition of the monomer mixture and the temperature—on the progress of the copolymerization, the molecular weight and the molecular weight distribution as well as on the composition of the copolymers obtained is reported. Conversion data for the variation of the mole ratio of comonomers show a maximum for an [Al]/[V] mole ratio of approximately 7, whereas the molecular weight of copolymers is not significantly influenced. An increase in the molecular weight of the copolymers can be obtained by an increase of butadiene content in the monomer mixture. However, there is also an increasing incorporation of butadiene into the copolymer. Raising the temperature from ?60°C to 0°C results in a significant decrease in molecular weight, whereas the composition of the copolymers is not significantly changed.  相似文献   
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Bone marrow-derived mesenchymal stem cells in repair of the injured lung   总被引:26,自引:0,他引:26  
We sought to determine whether an intact bone marrow is essential to lung repair following bleomycin-induced lung injury in mice, and the mechanisms of any protective effects conferred by bone marrow-derived mesenchymal stem cell (BMDMSC) transfer. We found that myelosupression increased susceptibility to bleomycin injury and that BMDMSC transfer was protective. Protection was associated with the differentiation of engrafted BMDMSC into specific and distinct lung cell phenotypes, with an increase in circulating levels of G-CSF and GM-CSF (known for their ability to promote the mobilization of endogenous stem cells) and with a decrease in inflammatory cytokines. In vitro, cells from injured, but not from normal, mouse lung produced soluble factors that caused BMDMSC to proliferate and migrate toward the injured lung. We conclude that bone marrow stem cells are important in the repair of bleomycin-injured lung and that transfer of mesenchymal stem cells protects against the injury. BMDMSC localize to the injured lung and assume lung cell phenotypes, but protection from injury and fibrosis also involves suppression of inflammation and triggering production of reparative growth factors.  相似文献   
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