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81.
82.
A community-based health survey for the time period between 1944 and 1995 was collected from 801 individuals who had lived downwind of the U.S. plutonium production facility located in Hanford, Washington. The results of the survey revealed high incidences of all cancers, including thyroid cancer. There were greater than expected numbers of central nervous system tumors and cancers that invaded the female reproductive system (e.g., cancers of the uterus, ovary, cervix, and breast). The authors argue that the greater-than-expected numbers found cannot be accounted for by selection bias alone. Comparisons of crude incidence rates, as well as of occurrence ratios between pairs of cancer types among Downwinders and reasonably similar populations, suggested that the excess neoplasms may be associated with radioactive contamination of food, water, soil, and/or air. In addition, a synergistic effect may exist with agricultural toxins. Previously neglected biophysical and physiological properties of internally lodged, long-lived 129I may be a significant etiological factor in the development of thyroid diseases, including cancer, and other malignancies in exposed populations.  相似文献   
83.
The vertebrate immune system monitors whether an organism is invaded by pathogens. Therefore, each cell has to prove itself as healthy. This is achieved by presenting fragments of intracellular protein degradation products on the surface, i.e., each cell displays peptides on specialised proteins known as major histocompatibility complex (MHC) class I proteins. A displayed peptide has to pass certain constraints before its presentation: It has to be excised out of a protein, translocated into the endoplasmic reticulum (ER) and fit into the binding groove of a MHC molecule. In theory, alteration of the cellular protein profile by mutation or infection should force pathogen-specific T-cells to take action via recognition of foreign peptide bound to MHC class I molecules on the cell surface. Unfortunately, pathogens and tumours have evolved many ways to affect antigen presentation and to escape from immune response. Understanding the exact mechanisms of antigen presentation, i.e., protein cleavage and peptide binding by MHC molecules, would allow their manipulation by drugs and lead to the re-establishment of the correct antigen presentation pathway. This review will summarise current knowledge of the mechanisms of antigen presentation and discuss putative targets for therapeutic treatment as well as for vaccination strategies.  相似文献   
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Gastrointestinal system changes following spinal cord injury (SCI) are generally less obvious than other body system changes. These alterations in function and the response to management, however, may have profound implications on the social, emotional, and physical well-being of the individual with SCI. This article reviews changes in gastrointestinal function following SCI and discusses current issues related to the management of the neurogenic bowel.  相似文献   
86.
Excel97在药物分析中的应用   总被引:1,自引:0,他引:1  
目的:在药物分析中,电子表格软件MicrosoftExce197for Windows。方法:利用Excel的数据处理功能,进行药物的图表绘制、数据计算和统计处理,回归分析,特别是计算分析,并可建立分析数据库。结果和结论:Excel操作简单,功能强大,数据分析工作直观。  相似文献   
87.
A case of recurrent paroxysmal sneezing in an adolescent girl is reported with a review of the literature. The mechanisms of sneezing are described. Most cases appear to have a psychogenic etiology. We postulate that this is a conversion symptom in which the patient received secondary gain and probably represents a pre-oedipal conflict.  相似文献   
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Five salivary gland hemangiomas in adults are reported. The feasibility of preoperative diagnosis on clinical and radiologic grounds is emphasized. Adult hemangiomas are of the cavernous type and can be differentiated from infantile capillary hemangiomas clinically as well as histologically. Cavernous hemangiomas in the adult should be treated by surgical excision.  相似文献   
90.
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