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101.
In previous work, a mouse line selected for resistance (R) to fescue toxicosis had higher activities of two hepatic Phase II detoxification enzymes than a mouse line selected for fescue toxicosis susceptibility (S). The primary objective of the present study was to determine whether those same lines also differed in hepatic Phase I enzyme activity, estimated from sleep time (ST) following sodium pentobarbital anesthesia. Additional objectives were to determine whether ST differences between lines were modulated by endophyte-infected fescue in the diet (with or without an enzyme inducer) and whether ST of individual mice was correlated with the effect of a toxin-containing diet on the postweaning growth of those mice. In Exp. I, 24 males from each line were randomly assigned to each of five diets: control (commercial rodent food meal); E+ (50% endophyte-infected fescue seed, 50% control); E+P (the E+ diet supplemented with 1,000 ppm phenobarbital); E- (50% endophyte-free fescue seed, 50% control); and E-P (the E- diet supplemented with 1,000 ppm phenobarbital). After 4 wk on these diets, ST was measured on all the mice. A second ST was recorded on each mouse by randomly sampling one-fourth of the population after 1, 2, 3, or 4 wk on a pelleted rodent food diet. Regardless of diet, R mice had shorter first and second ST than S mice (P < 0.01), suggesting higher hepatic Phase I microsomal enzyme activity. Mice on both phenobarbital-supplemented diets had shorter first ST than mice whose diets did not include that microsomal enzyme inducer (P < 0.01). In Exp. II, ST was measured on male and female R and S mice (n = 280) after they had been fed the E- diet for 2 wk, then the E+ diet for 2 wk, and then a pelleted rodent food diet for 2 wk. Growth response to the E+ diet was the percentage of reduction in gain on the E+ diet compared to gain on the E- diet the previous 2 wk. As in Exp. I, S mice slept longer than R mice (P < 0.01). The residual correlation between ST and gain reduction associated with the E+ diet equaled 0.04. Thus, an animal's apparent Phase I enzyme activity did not predict its growth rate depression on the toxin-containing diet. Based on these and previous studies, divergent selection for toxicosis response in mice was successful partially by causing divergence in activities of hepatic Phase I and II detoxification enzymes. 相似文献
102.
On the basis of a systematic review of the literature, this paper provides the first evidence-based maps of the distribution of the major vector-borne parasitic infections of dogs and cats in Europe. From an initial survey of 894 publications, data from 268 were analysed, summarised and collated. Prevalence data were used to calculate the force of infection to provide distribution and incidence maps for canine infections with Leishmania infantum, Dirofilaria immitis, Dirofilaria repens, Babesia canis and Ehrlichia canis. There was little information from some areas but, in spite of its acknowledged incompleteness, the study provides an evidence-based framework upon which to assess the risks of infection, and will provide a basis, by correlation with climatic and vegetation data, to derive more comprehensive risk assessment maps for Europe. To clinicians in both endemic and non-endemic countries, it will be of assistance in decision-making with respect to diagnosis and preventive measures. 相似文献
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Stocum DL 《Science (New York, N.Y.)》2002,298(5600):1901-1903
108.
ABSTRACT Phaeocryptopus gaeumannii is a widespread foliar parasite of Douglas-fir. Although normally innocuous, the fungus also causes the defoliating disease Swiss needle cast in heavily infected needles. The extent of P. gaeumannii colonization in Douglas-fir foliage was estimated with real-time quantitative polymerase chain reaction (PCR) using TaqMan chemistry. In order to derive a normalized expression of colonization, both pathogen and host DNA were simultaneously amplified but individually detected by species-specific primers and TaqMan probes labeled with different fluorescent dyes. Detection of host DNA additionally provided an endogenous reference that served as both an internal positive control and adjusted for variation introduced by sample-to-sample differences in DNA extraction and PCR efficiencies. The genes employed for designing the TaqMan probes and primers were beta-tubulin for the pathogen and a LEAFY/FLORICAULA-like gene involved in floral development for the tree host. Both probe/primer sets exhibited high precision and reproducibility over a linear range of 4 orders of magnitude. This eliminated the need to analyze samples in multiple dilutions when comparing lightly with heavily infected needles. Quantification of the fungus within needles was successful as early as 1 month after initial infection. Real-time PCR is the only method currently available to quantify P. gaeumannii colonization early in the first year of the colonization process. 相似文献
109.
Two Vietnamese pot-bellied pigs (Sus scrofa) were euthanatized after they developed abdominal distension. Necropsy of both pigs revealed large myometrial neoplasms and cystic endometrial hyperplasia. Multiple discrete smaller myometrial neoplasms were also observed in one pig; however, distant metastases were not observed in either animal. The tumors were diagnosed as leiomyomas on the basis of histologic examination and immunohistochemistry. This is the first detailed report of uterine leiomyomas in swine, and it is suggested that this diagnosis may become more common as more aging pigs are examined. 相似文献
110.
The aim of the present study was to evaluate possible injury provoked by an intensive reproductive programme based on rectal palpation in the cow. Alterations to the mesothelial surface of the peritoneum and to the oviductal mucosa were explored by scanning electron microscopy (SEM). Nine multiparous Friesian cows were selected from each of two commercial dairy herds. Cows in herd 1 were maintained on a weekly reproductive health programme, while those in herd 2 were not subjected to gynaecological exploration. Surface features of the mesothelial cells of the reproductive tract and adjacent ligaments, and the oviductal mucosa were explored by SEM observation of tissue specimens from each animal. Six cows in the intensive reproductive programme showed microscopic alterations of the peritoneal surface. Strands were observed in the oviducts and adjacent ligaments in five of these cows. These strands, composed of filaments covered with mesothelial cells, were probably adhesions. Cells with abundant vacuoles on their surface were detected in the mesothelium corresponding to three animals, two of which also showed microscopic strands. No peritoneal surface alterations were observed in the cows from herd 2. No oviductal mucosal modifications were detected in either group. These findings suggest that intensive reproductive programmes based on rectal palpation may increase the risk of peritoneal surface alterations in the cow, but effects on reproductive physiology are unlikely. 相似文献