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781.
Placental abnormalities are the main factor in the high incidence of somatic cell clone abnormalities. The expression of several trophoblast cell-specific molecules is enhanced during gestational days 7 to 14. To determine the possible genes whose expression patterns might reflect calf normality, we first compared the gene expression profiles on day 15 between in vitro-fertilized (IVF) embryos and two types of somatic cell nuclear-transferred embryos with either a high (FNT) or low (CNT) incidence of neonatal abnormalities using a cDNA microarray containing 16 of 21 placenta-specific genes developed from tissues collected across gestation. To identify significant genes from the screening of day 15 embryos, genes with a less than two-fold difference in expression between IVF and CNT embryos, and those with a greater than two-fold difference between IVF and FNT and between CNT and FNT were considered to contribute to clone abnormalities. These two comparisons revealed 18 down-regulated and 18 upregulated genes of the 1722 genes examined. We then examined the expression levels of 10 genes with known functions in eight-cell and blastocyst-stage embryos by real-time PCR. The mRNA expression pattern of interferon (IFN)-tau, a trophectoderm-related gene, differed between IVF, CNT, and FNT eight-cell embryos; few or none of the IVF or CNT eight-cell embryos expressed IFN-tau mRNA, but all eight-cell FNT embryos expressed IFN-tau. IFN-tau mRNA expression was significantly higher in IVF blastocysts, however, than in nuclear-transferred blastocysts. Average IFN-tau mRNA expression in FNT blastocysts was not different from that in CNT blastocysts, due to one CNT blastocyst with high expression. The precise relation between early expression of IFN-tau mRNA and inferior developmental potential in cloned embryos should be examined further.  相似文献   
782.
IL-17 is a cytokine that induces neutrophil-mediated inflammation, but its role in protective immunity against intracellular bacterial infection remains unclear. In the present study, we demonstrate that IL-17 is an important cytokine not only in the early neutrophil-mediated inflammatory response, but also in T cell-mediated IFN-gamma production and granuloma formation in response to pulmonary infection by Mycobacterium bovis bacille Calmette-Guérin (BCG). IL-17 expression in the BCG-infected lung was detected from the first day after infection and the expression depended on IL-23. Our observations indicated that gammadelta T cells are a primary source of IL-17. Lung-infiltrating T cells of IL-17-deficient mice produced less IFN-gamma in comparison to those from wild-type mice 4 wk after BCG infection. Impaired granuloma formation was also observed in the infected lungs of IL-17-deficient mice, which is consistent with the decreased delayed-type hypersensitivity response of the infected mice against mycobacterial Ag. These data suggest that IL-17 is an important cytokine in the induction of optimal Th1 response and protective immunity against mycobacterial infection.  相似文献   
783.
In this study we examined the role of the nitrogen-fixing tree, Robinia pseudoacacia (black locust), in ectomycorrhizal (ECM) formation and ECM community of Pinus thunbergii (Japanese black pine) seedlings. Two 200 m(2) experimental plots were established at the border between a Japanese black pine- and a black locust-dominated area in a coastal forest. The ECM fungal community of pine seedlings was examined by PCR-RFLP and sequence analysis. We analyzed the relationship between ECM formation, ECM community, growth, and nutrient status of pine seedlings and environmental conditions using the Mantel test and structural equation model. Percentages of ECM root tips, the number of ECM fungal species and ECM diversity on pine seedlings decreased in the black locust-dominated area. Cenococcum geophilum and Russula spp. were dominant in the Japanese black pine-dominated area, whereas Tomentella spp. were dominant in the black locust-dominated area. Nitrogen (N) concentration in soils or pine seedlings strongly influenced the percentage of ECM root tips, the number of ECM fungal species and ECM fungal similarity. These results imply the long-term eutrophication caused by N-fixing trees can change ECM formation and ECM community structure.  相似文献   
784.
Integrated design of both porous structure and crystalline morphology is expected to open up the way to a new class of materials. This report demonstrates new nanostructured Li4Ti5O12 materials with hierarchically porous structures and flower‐like morphologies. Electrochemical studies of the electrodes of Li‐ion and Na‐ion batteries clearly reveal the advantage of nanoarchitectural design of active materials. In addition, the temperature dependence of Na+‐insertion/extraction capacity in relation to Li4Ti5O12 electrodes is for the first time evaluated and it is found that elevation of the cell operating temperature effectively improves the rate capability of the Na‐ion batteries. Based on the new findings, it is suggested that specially designed Li4Ti5O12 materials allow for high‐performance Na‐ion batteries that are available as large‐scale storage devices for applications such as automotive and stationary energy storage.  相似文献   
785.
The dynamics of nucleosomes containing either canonical H3 or its centromere-specific variant CENP-A were investigated using molecular dynamics simulations. The simulations showed that the histone cores were structurally stable during simulation periods of 100 ns and 50 ns, while DNA was highly flexible at the entry and exit regions and partially dissociated from the histone core. In particular, approximately 20–25 bp of DNA at the entry and exit regions of the CENP-A nucleosome exhibited larger fluctuations than DNA at the entry and exit regions of the H3 nucleosome. Our detailed analysis clarified that this difference in dynamics was attributable to a difference in two basic amino acids in the αN helix; two arginine (Arg) residues in H3 were substituted by lysine (Lys) residues at the corresponding sites in CENP-A. The difference in the ability to form hydrogen bonds with DNA of these two residues regulated the flexibility of nucleosomal DNA at the entry and exit regions. Our exonuclease III assay consistently revealed that replacement of these two Arg residues in the H3 nucleosome by Lys enhanced endonuclease susceptibility, suggesting that the DNA ends of the CENP-A nucleosome are more flexible than those of the H3 nucleosome. This difference in the dynamics between the two types of nucleosomes may be important for forming higher order structures in different phases.  相似文献   
786.
Genetic predisposition and environmental factors influence the development of human autoimmune disease. Occupational exposure to crystalline silica (cSiO2) has been etiologically linked to increased incidence of autoimmunity, including systemic lupus erythematosus (SLE), but the underlying mechanisms are poorly understood. The purpose of this study was to test the hypothesis that early repeated short-term cSiO2 exposure will modulate both latency and severity of autoimmunity in the lupus-prone female NZBWF1 mouse. Weekly intranasal exposure to cSiO2 (0.25 and 1.0 mg) for 4 wk beginning at 9 wk of age both reduced latency and increased intensity of glomerulonephritis. cSiO2 elicited robust inflammatory responses in the lungs as evidenced by extensive perivascular and peribronchial lymphoplasmacytic infiltration consisting of IgG-producing plasma cells, and CD45R+ and CD3+ lymphocytes that were highly suggestive of ectopic lymphoid tissue (ELT). In addition, there were elevated concentrations of immunoglobulins and the cytokines MCP-1, TNF-α and IL-6 in bronchoalveolar lavage fluid. cSiO2-associated kidney and lung effects paralleled dose-dependent elevations of autoantibodies and proinflammatory cytokines in plasma. Taken together, cSiO2-induced pulmonary inflammation and ectopic lymphoid neogenesis in the NZBWF1 mouse corresponded closely to systemic inflammatory and autoimmune responses as well as the early initiation of pathological outcomes in the kidney. These findings suggest that following airway exposure to crystalline silica, in mice genetically prone to SLE, the lung serves as a platform for triggering systemic autoimmunity and glomerulonephritis.  相似文献   
787.
Abstract Endotoxic activities of lipopolysaccharide (LPS) isolated from Burkholderia (Pseudomonas) pseudomallei , a causative agent of melioidosis, were investigated. Compared to an enterobacterial LPS (SAE-LPS), B. pseudomallei LPS (BP-LPS) exhibited weaker pyrogenic activity in rabbits, lethal toxicity in galactosamine-sensitized mice and murine macrophage activation, i.e. production of tumor necrosis factor, interleukin-6 and nitric oxide. BP-LPS, on the other hand, exhibited stronger mitogenic activity to murine splenocytes than SAE-LPS; moreover, it stimulated even the splenocytes of LPS-resistant C3H/HeJ mice. Unusual chemical structures in the acid-stable inner core region attached to the lipid A moiety of BP-LPS may be responsible for this strong mitogenic activity.  相似文献   
788.
Fine Structure and Morphogenesis of Borna Disease Virus   总被引:8,自引:2,他引:6       下载免费PDF全文
Borna disease virus (BDV), a negative nonsegmented single-stranded RNA virus, has not been fully characterized morphologically. Here we present what is to our knowledge the first data on the fine ultrastructure and morphogenesis of BDV. The supernatant of MDCK cells persistently infected with BDV treated with n-butyrate contained many virus-like particles and more BDV-specific RNA than that of untreated samples. The particles were spherical, enveloped, and approximately 130 nm in diameter; had spikes 7 nm in length; and reacted with BDV p40 antibody. A thin nucleocapsid, 4 nm in width, was present peripherally in contrast to the thick nucleocapsid of hemagglutinating virus of Japan. The BDV particles reproduced by budding on the cell surface.  相似文献   
789.
Cultivated diploid potatoes (2n = 2x = 24) are self-incompatible, but can be altered to become self-compatible using the Sli gene. Previously, a diploid clone 97H32-6 was selfed up to S3 using the Sli gene. To explore the usefulness of the Sli gene for the production of highly homozygous diploid potatoes, 2 S4 families from the above 97H32-6 derived S3 lines (inbred series A) and 3 S5 families by continuous selfings from a different F1 (= S0) plant (inbred series B) were developed. The level of heterozygosity and the location of heterozygous loci on the genetic map were investigated using RFLP and AFLP markers. The average heterozygosity levels of the originally heterozygous loci decreased from 100% in S0 to 10.7% in S4 and 8.6% in S5 (inbred series A and B, respectively). The average rate of reduction in heterozygosity per generation (38.4% and 38.5% for inbred series A and B, respectively) was lower than the theoretically expected rate (50%). However, none of the loci or chromosome sections was exclusively heterozygous in the advanced self-progeny. Thus, highly homozygous and seed-propagated diploid potatoes could be obtained by repeated selfing using the Sli gene.  相似文献   
790.
Abstract: The cellular level of ATP and related compounds in ischemic gerbil brain was investigated by high performance liquid chromatography (HPLC). Brain samples were obtained in situ following ligation of the common carotid artery. AMP and ADP peaks in the brain extracts in the ischemic group became much larger whereas the ATP peak decreased dramatically. The most striking finding was an extensive increase of adenosine: 50–100 fold. The levels of inosine and hypoxanthine also increased greatly in typical symptomatic gerbil.  相似文献   
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