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Estimated half-lives of mercury following methylmercury exposure in humans are 52-93 d for whole body and 49-164 d for blood. In its most recent 1980 review, the World Health Organization concluded that there was no evidence to suggest that brain half-life differed from whole-body half-life. In the present study, female monkeys (Macaca fascicularis) were dosed for at least 1.7 yr with 10, 25, or 50 micrograms/kg.d of mercury as methylmercuric chloride. Dosing was discontinued, and blood half-life was determined to be about 14 d. Approximately 230 d after cessation of dosing, monkeys were sacrificed and organ and regional brain total mercury levels determined. One monkey that died while still being dosed had brain mercury levels three times higher than levels in blood. Theoretical calculations were performed assuming steady-state brain:blood ratios of 3, 5, or 10. Brain mercury levels were at least three orders of magnitude higher than those predicted by assuming the half-life in brain to be the same as that in blood. Estimated half-lives in brain were between 56 (brain:blood ratio of 3) and 38 (brain:blood ratio of 10) d. In addition, there was a dose-dependent difference in half-lives for some brain regions. These data clearly indicate that brain half-life is considerably longer than blood half-life in the monkey under conditions of chronic dosing.  相似文献   
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We examined a nationally representative sample of 60 adult day care centers to describe the state of this evolving care modality after a decade's growth. Results indicate that day care centers can be categorized into three models of care, each of which serves a distinctive subpopulation. Model appropriateness was tested with analysis of variance of differences in participant characteristics. Services, staffing, costs, and other program features are contrasted among the three models.  相似文献   
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Summary Pharmacokinetic studies of methotrexate have been carried out in 21 children with acute lymphoblastic leukemia diagnosed in 1981. Children were treated with intermediate dose (500 mg/m2) methotrexate in keeping with the 1981 ALL treatment Protocol of the Hungarian Childhood Leukemia Working Group. Of the 21 children, 8 relapsed, and 13 are in continuous complete remission. In the relapsed patients significantly increased systemic clearance of methotrexate was observed at the time of the second methotrexate treatment cycle compared with the calculated value after the first administration of the drug. No such change in the clearance was found in patients who are still in remission. There was no difference between children who relapsed or who are in remission in the elimination half-time of the drug. Age, sex, WBC at diagnosis, and systemic clearance of methotrexate were found to be connected with the probability of relapse in the patients studied. The possible reasons for the prognostic role of systemic methotrexate clearance are discussed.  相似文献   
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Basic surgical techniques and variations of endoscopic sinus surgery   总被引:2,自引:0,他引:2  
This article gives complete information on the care of the endoscopic sinus surgery patient. Indications and preoperative evaluations necessary for endoscopic sinus surgery are described. The technique of functional endoscopic sinus surgery is covered in detail. Postoperative care and complications are also described. Various procedures for patients with extensive or unusual disease are discussed.  相似文献   
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The authors review the relationship that has evolved over the years between the Department of Psychiatry at Oregon Health Sciences University and Oregon's community and state mental health programs. They describe the compatibility that exists between the basic requirements of academic psychiatry departments and public mental health programs and demonstrate how these organizations have been able to fulfill one another's needs in Oregon. Specific examples of successful collaborations in the areas of education, administration, research, and service are presented to illustrate how relationships that have been designed to meet specific requirements of one organization can fulfill many requirements of both. Suggestions are provided for those organizations contemplating similar collaborative endeavors.  相似文献   
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