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To evaluate sites of enterovirus replication and to characterize the resulting lesions, twenty 4-day-old specific-pathogen-free (SPF) turkey poults were orally inoculated with an enterovirus. Twenty uninoculated SPF poults served as controls. Inoculated poults were depressed, had ruffled feathers, watery droppings, and pasted vents. Gross lesions were dilated thin-walled ceca with foamy yellow fluid. Immune electron microscopy of the gastrointestinal tract contents revealed an enterovirus with an average diameter of 23.5 nm. Immunoperoxidase and indirect immunofluorescent antibody assays revealed intracytoplasmic staining in enterocytes of the duodenum, jejunum, and ileum. This correlated with the scanning electron microscopy findings, which showed the most lesions in the jejunum and ileum. The ileum had prominent cell outlines because of rounded, distinct, bulging epithelial cells. Histopathology revealed slight shortening of villi and increased crypt depth in the intestines of inoculated poults. Our findings indicate that the small intestine is the site of turkey enterovirus replication, and the gross and microscopic changes observed are determined to result from viral damage to the enterocytes. 相似文献
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V Beswick R Guerois F Cordier-Ochsenbein YM Co?c HD Tam J Tostain JP No?l A Sanson JM Neumann 《Canadian Metallurgical Quarterly》1999,28(1):48-58
PURPOSE: To identify specific alcohol use beliefs and behaviors among local high school students; to determine whether relationships exist between alcohol use and various sociodemographic and lifestyle behaviors; and to assist in the development and implementation of alcohol abuse prevention programs. METHODS: This cross-sectional study involved the completion of a questionnaire by 1236 Grade 9-13 students (86% response rate) from 62 randomly selected classrooms in three Canadian urban schools. Data analyzed here are part of a larger lifestyle survey. RESULTS: A total of 24% of students reported never having tasted alcohol, 22% have tasted alcohol but do not currently drink, 39% are current moderate drinkers, 11% are current heavy drinkers (five or more drinks on one occasion at least once a month), and 5% did not answer. Reasons stated most often for not drinking were "bad for health" and "upbringing," while reasons stated most often for drinking were "enjoy it" and "to get in a party mood." Student drinking patterns were significantly related to gender, ethnicity, grade, and the reported drinking habits of parents and friends. Older male adolescents who describe their ethnicity as Canadian are at higher risk for heavy drinking than students who are younger or female, or identify their ethnicity as European or Asian. Current heavy drinkers are at higher risk than other students for engaging in other high-risk behaviors such as drinking and driving, being a passenger in a car when the driver is intoxicated, and daily smoking. CONCLUSIONS: Heavy alcohol use in adolescents remains an important community health concern. Older self-described Canadian and Canadian-born male adolescents are at higher risk for heavy drinking. Current and heavy drinking rises significantly between Grades 9 and 12. Students who drink heavily are more likely to drink and drive, to smoke daily, and to have friends and parents who drink alcohol. 相似文献
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Exposure to cadmium (Cd) impairs renal transport systems for glucose, amino acids, phosphate, and dicarboxylates. To investigate if these changes are directly related to a Cd binding to the renal brush-border membrane, Cd binding and the Na+-dependent uptakes of d-glucose, l-alanine, phosphate, and succinate were determined in rat renal brush-border membrane vesicles (BBMV) exposed to CdCl2. Cd uptake by BBMV showed time and concentration dependence. Changes in medium osmolality had no effect on Cd uptake, indicating that the process primarily involves binding of Cd to the membrane. Scatchard analysis indicated the presence of two types of Cd binding sites, differing in affinity and number. Increasing the medium Cd concentration from 50 to 200 microM resulted in a progressive increase in Cd binding to the membrane and decrease in Na+-dependent transport of d-glucose, l-alanine, inorganic phosphate, and succinate. In all cases, the inhibition of transport was directly proportional to the total amount of Cd binding to the membrane. These results suggest that, during chronic exposure to Cd, free Cd ions liberated in renal tubular cells may directly interact with brush-border membranes and impair Na+-dependent solute transports. 相似文献
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Ascorbyl free radical (AFR), can be considered as an atoxic and endogenous indicator of oxidative stress. The purpose of our experiments was to investigate the influence of the severity and length of ischemia on the extent of AFR release during myocardial ischemia and reperfusion. For that purpose, isolated perfused rat hearts were submitted to a global ischemia, either total (residual flow 0%) or low flow (residual flow 5%), of 20 or 60 min length. Coronary effluents were collected at different times of experimentation and analyzed with Electron Spin Resonance (ESR) spectroscopy. AFR ESR doublet (g = 2.0054, aH = 0.188 MT) was not detected in coronary effluents collected during control perfusion periods. Nevertheless, during low-flow ischemia, a weak AFR release was noted. Moreover, a sudden and massive AFR liberation was observed at the time of reperfusion: this AFR release was weaker after low-flow ischemia than after total ischemia and was enhanced when the duration of ischemia increased from 20 min to 60 min. The large liberation of AFR noticed during global total ischemia was associated with a greater depression in myocardial contractile function and a lower recovery in coronary flow. In conclusion, our study demonstrates that AFR production at the time of reperfusion depends on the duration and strength of the ischemia, and is related to free radical injury. According to previously described ascorbate/AFR properties, we can conclude that AFR liberation in coronary effluents could represent a marker of oxidative stress during ischemia and/or reperfusion of hearts. This AFR release could be considered a sign of the severity of the ischemic episode, and could be related to the functional impairment during reperfusion. 相似文献
139.
Paradoxical effect of GM-CSF gene transfer on the tumorigenicity and immunogenicity of murine tumors
J Wang WK Yang Y Yang SJ Wei DM Yang J Whang-Peng YM Chen KL Ting CC Ting 《Canadian Metallurgical Quarterly》1998,75(3):459-466
Because forensic psychiatry is a relatively small field, there are few computer applications designed particularly for it. Forensic psychiatrists use personal computer in many ways that are similar to other psychiatrists, but certain aspects of forensic practice, such as an emphasis on precise reports, regular interactions with attorneys, use of legal databases and materials, and travel, call for utilizing available programs in different ways. Since forensic psychiatry draws on the knowledge of psychiatry, law, and criminology, the World Wide Web has become a particularly useful resource for information. An array of applications and resources of particular interest to forensic psychiatrists are presented. Computer education, "telemedicine," and teleconferencing are still in their infancy in forensic psychiatry, but are likely to increase in use as these technologies mature. 相似文献
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