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排序方式: 共有162条查询结果,搜索用时 15 毫秒
71.
A I Khalafalla M A Fadol O A Hameid Y A Hussein M el Nur 《Acta veterinaria Hungarica》1992,40(4):329-333
Six Newcastle disease virus (NDV) isolates were obtained from disease outbreaks on different poultry farms in the Sudan between 1988 and 1991. The pathogenic properties of these isolates were studied in comparison to those of strain Herts 33/56. All the isolates were similar in that they killed chicken embryos quickly, in mean death time (MDT) and embryo lethal dose 50 per cent (ELD50), had higher intracerebral pathogenicity indices (ICPI), and produced viscerotropic lesions in the infected chickens. The field isolates had the characteristics of the velogenic viscerotopic strains of NDV. The pathogenesis of infection caused by one of the isolates was studied. The virus was first detected in different organs and in oral and cloacal swabs on the third day after infection. 相似文献
72.
Apoptosis seems to play an important role in the pathogenic profile of bovine herpesvirus 1 (BHV-1) infection. Nitric oxide (NO) is also important as a signal molecule. In this study, apoptosis was selectively induced in HEp-2 cells in the early stage [1-3 h postinfection (PI)] of BHV-1 multiplication, and this apoptotic process was realised through the caspase-8, and partially through the caspase-3, pathway. BHV-1 infection inhibited staurosporine- (SS-) induced apoptosis only if the SS was added at 6 h PI. The results of this study showed that the 'NO-apoptosis' relation was realised through the caspase-8 pathway ('outer membrane receptor' pathway) at a later stage of infection in apoptosis induced by BHV-1 + SS. Our previous report (Yazici et al., 2004) and this study together showed that BHV-1 might induce and inhibit cell-type-specific pathways of apoptosis. 相似文献
73.
Activated carbon was prepared from an agricultural waste, coconut coir, and its characteristics were compared with that of
a commercial bituminous coal-based activated carbon. The activated carbon possessed higher surface area, micropore area, micropore
volume and average pore diameter, and well-developed meso- and micropores. Batch test on adsorption of chromium(VI) by the
coconut coir activated carbon showed that the extent of chromium(VI) adsorption was dependent on chromium(VI) concentration,
contact time, pH and activated carbon dose. Maximum adsorption occurred at pH 1.0–2.0 and equilibrium adsorption was attained
in 2.5 h. Chromium(VI) adsorption followed pseudo second-order kinetics. Equilibrium chromium(VI) adsorption data for the
coconut coir activated carbon and the commercial activated carbon were described by the Langmuir and Freundlich isotherm models
and indicated higher chromium(VI) adsorption capacity of the coconut coir activated carbon. Chromium(VI) adsorption capacity
of the coconut coir activated carbon was compared with that of activated carbon prepared from different waste material and
bituminous coal. The coconut coir activated carbon showed high limiting capacity for adsorption of chromium(VI). Coconut coir
activated carbon is a suitable substitute for commercial activated carbon in the adsorptive removal of chromium(VI) from water. 相似文献
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OBJECTIVES: To investigate the prevalence of anaemia and subclinical vitamin A deficiency among adolescent schoolboys in Dhaka City, Bangladesh, and to identify factors related to anaemia and vitamin A status.DESIGN: A cross-sectional study.SETTING: Government high schools in Dhaka City, Bangladesh.SUBJECTS AND METHODS: A total of 381 boys, aged 11-16 years, from 10 schools in Dhaka City participated in the study. Socio-economic, anthropometric and dietary data were collected. Haemoglobin and serum retinol (vitamin A) concentrations were determined.RESULTS: Seven per cent of the boys were anaemic and 22% had serum vitamin A levels below the adequate level of 1.05 micromol l(-1), with only 1.5% having subclinical vitamin A deficiency (<0.70 micromol l(-1)). Food frequency data revealed poor dietary habits. Multiple regression analysis showed that age, body mass index (BMI), parents' occupation, serum vitamin A level and frequency of intakes of meat and fruit were significantly independently related to haemoglobin level. The overall F-ratio (13.1) was highly significant (P<0.000) and the adjusted R(2) was 0.192. For serum vitamin A, BMI, father's education, per capita expenditure on food, haemoglobin concentration and frequency of intake of vitamin A-rich fruit were found to be significantly independently related. The overall F-ratio (14.5) was highly significant (P<0.000) and the adjusted R(2) was 0.186.CONCLUSION: The data show that adolescent schoolboys in Dhaka City have anaemia and inadequate vitamin A status, although the extent of the problems is lower than in other population groups in the country. Sociodemographic and dietary factors appear to have important relationships with anaemia and vitamin A status of these boys. 相似文献
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77.
Rigidoporus microporus is an economically important plant pathogenic fungus causing particularly severe losses to the rubber industry worldwide. The pathogen is responsible for white root rot (WRR) disease, infecting the host roots via white fibrous mycelia, causing vascular disfunction, and visible symptoms including leaf discolouration and dieback in severely infected trees. The final stage of the disease is characterized by the appearance of basidiocarps at the tree collar. The development of WRR in rubber plantations is dependent on fungal diversity in the soil, pH, temperature, and cation levels. Several ‘-omics’ approaches have been undertaken to understand how R. microporus functions with the objective, ultimately, to control WRR. Unfortunately, no resistant rubber clone has been identified to date. The disease is managed through physical and chemical methods that are laborious and negatively impact the environment, respectively. Recent developments in research on R. microporus shed light on potential sustainable routes to WRR disease control using beneficial microorganisms and natural compounds. This review discusses the characteristics of R. microporus isolates from different geographical origins, the pathogenicity and virulence mechanisms of the necrotrophic fungal pathogen, factors that influence the development of WRR, recent findings from the multi-omics studies, and control methods that are available to combat this economically important pathogen. 相似文献
78.
Al‐Nur Md. Iftekhar Rahman Seiya Yamashita Md. Rashedul Islam Taisuke Fujihara Hayato Yamaguchi Manabu Kawahara Masashi Takahashi Hideyuki Takahashi Takafumi Gotoh Nobuhiko Yamauchi 《Animal Science Journal》2020,91(1)
This study investigated the effect of type‐I interferon (IFN) on the expression of matrix metalloproteinases (MMPs) of the bovine endometrial stromal cells (BES) and epithelial cells (BEE). The cells were separated and purified from the caruncles and cultured in DMEM/F‐12 containing 10% fetal bovine serum. Spheroids were generated by using ascorbate. Zymograms of the supernatant showed that BEE predominantly expressed MMP‐9, whereas MMP‐2 was expressed in BES and homo‐spheroids. While MMPs expression was not detected in hetero‐spheroids. Real‐time quantitative PCR revealed that type‐I IFN and P4 suppressed the gene expression of MMP‐2 and MMP‐9 in hetero‐spheroids, respectively. On the other hand, gelatin zymography analysis of the supernatant showed that type‐I IFN strongly promote the clearance of MMPs. While zymograms of the MMPs stocked in the hetero‐spheroids were significantly reduced by type‐I IFN. Phenylmethanesulfonyl fluoride and leupeptin (both are serine proteinase inhibitors) significantly repressed the clearance of MMP‐2 and MMP‐9 induced by type‐I IFN. Moreover, collagen fibers in hetero‐spheroids significantly decreased after the treatment with type‐I IFN. In conclusion, it was suggested that type‐I IFN participate in the tissue remodeling by regulation the clearance of MMPs. 相似文献
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