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排序方式: 共有132条查询结果,搜索用时 31 毫秒
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Schlenker G Müller W Birkelbach C Glatzel P 《Berliner und Münchener tier?rztliche Wochenschrift》1999,112(1):14-17
Together with the faecal and the urinary discharge of animals and humans natural and synthetic estrogenes are excreted into the environment. About their degradation in the environment only few facts are known. Their reduction is probably of microbial enzymatical nature. For looking into that question it was investigated by in-vitro-attempts whether Escherichia coli or Clostridium perfringens influence the estrone. Therefore estrone was incubated together with the microorganisms tested (experimental groups) and without those (control groups) in nutrient medium for these bacteria over 48 hours with 37 degrees C (aerobic) or 42 degrees C (anaerobic). For the executed procedure an enzyme immunoassay was used. It could be seen that E. coli does not show a provable effect on the estrone concentration under this conditions. Whereas C. perfringens might have a potency for the degradation of the hormone tested. The experiments shows that there exists obviously a difference between estrone and 4-pregnene-20 beta-o1-3-one in the same system of test. 相似文献
3.
Transmissible spongiform encephalopathies are degenerative disorders affecting the central nervous system (CNS) occurring in a variety of species. The causative agent is thought to be composed of an abnormal form of the host encoded prion protein (PrPC), termed PrPSc. The conformational change of PrPC into PrPSc can occur spontaneously, however, it can also be induced by PrPSc. Prion diseases such as bovine spongiform encephalopathy (BSE), scrapie and variant Creutzfeldt-Jakob-Disease (vCJD) are most likely caused by peripheral uptake of prions. The process by which prions proceed to the CNS following peripheral uptake is referred to as neuroinvasion. Infection with prions is thought to occur in two phases: After ingestion prions first replicate in lymphatic tissue and then gain access to the CNS via peripheral nerves. Studies looking at the biochemical and clinical characteristics of BSE and vCJD demonstrated that BSE is most likely responsible for vCJD in humans. 相似文献
4.
Transmissible spongiform encephalopathies in humans 总被引:1,自引:0,他引:1
Transmissible spongiform encephalopathies (TSE) are dementing diseases and have been known to affect humans for over 90 years. The most common of these is the sporadic form of Creutzfeldt-Jakob disease (sCJD), followed by its familial (fCJD) and an iatrogenic (iCJD) form. 1996 a variant of CJD (vCJD) has been described in the UK, of which so far 131 cases have been observed worldwide. Specific biochemical and neuropathological signatures allow to distinguish between vCJD and sCJD and lead to the hypothesis that vCJD is due to transmission of BSE prions to humans. Although promising therapeutical approaches are being investigated, human TSE remain untreatable entities. Thus preventive measures are essential. In Switzerland the population has been exposed to BSE prions, too, but no case of vCJD as described in the UK has been observed until now. Since 2001, however, a so far unexplained increase of sCJD cases is being observed. 相似文献
5.
Schröer U Lange A Glatzel P Ludwig H Borchers K 《Berliner und Münchener tier?rztliche Wochenschrift》2000,113(2):53-59
The aim of the present study was to clarify whether an EHV-1 induced abortion can be prognosticated by an increase of antibody titres, virus shedding and/or viraemia and whether the current abortion diagnostic is suitable. In this context the immune response post immunization and a possible reactivation were of great interest. For this purpose blood samples of 32 mares between the ages of 5-21 years were regularly investigated during a period of two years before and after vaccination and pregnancy. Neutralization tests, indirect immunofluorescence tests as well as PCR and virus isolation were used for EHV-1 diagnostics. It could be shown that the horses reacted individually to vaccination. In 14 cases a EHV-1-reactivation was suggested. An abortion prognosis was not possible even using serological, virological and molecular biological parameters. In addition, virus shedding and antibody titres were individual. An acute infection was detectable by a significant rise of antibodies and viraemia as well as virus shedding in the secretions. For the abortion diagnostics the antigen detection in combination with virus isolation and PCR from fetal lungs gave reliable results. In addition, the virological and serological investigation of the mare is recommendable. For prophylaxis we would advise a regular vaccination and strict hygiene. 相似文献
6.
Eduard Paulus 《European Journal of Forest Research》1862,6(1):1-1
Ohne Zusammenfassung 相似文献
7.
Carl Eduard Reh 《Forstwissenschaftliches Centralblatt》1903,25(4):177-189
Ohne Zusammenfassung 相似文献
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Some aspects of the reproductive biology of Charybdis feriatus (Linnaeus) were investigated to identify suitable techniques for broodstock management and seed production. Likewise, factors such as ablation, water depth and light requirements affecting survival or reproductive performance were tested. Production of megalops in tanks and juveniles in net cages installed in earthen ponds was conducted. Wild‐caught berried females produced a significantly higher number of zoeae per gram body weight (BW) of the female (3300±600) than captive spawners (867±58). Ablated and unablated crabs spawned after a month and ovaries of both had oocytes in all developmental stages after spawning, indicating that ablation was not necessary. Broodstock survived higher when stocked in 1 m‐deep water and kept in dark conditions compared with shallow (0.5 m depth) water or ambient lighting. There were six zoea and one megalopa stage. Megalops were produced (survival of 2–22% in 1 tonne or 23–55% in 3 L tanks) when methods for the mud crab Scylla serrata (Forsskål) were used, but feeding with Artemia started only at the Z4 stage. Survival of megalops after 1 month was higher when stocked in net cages installed in an earthen pond (32–82%) than when reared continuously in land‐based tanks (5–11%). 相似文献