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We recently showed that the activity of cerebellar Golgi cells can be powerfully modulated by stimulation of peripheral afferents, in a pattern different to local Purkinje cells. Here we have examined the pathways underlying these responses. Graded electrical stimulation of muscle and cutaneous nerves revealed that long-lasting depressions and short-lasting excitations of Golgi cells were evoked by stimulation of cutaneous nerves at stimulus intensities that activated large mechanoreceptive afferents, and grew as additional afferents were recruited. In contrast, none of the neurones responded to stimulation of muscle nerves at intensities that activated group I afferents, although about half responded with long-lasting depressions, but not excitations, to stimuli that recruited group II and III afferents. Selective lesions of the spinal dorsal columns did not affect either of these types of response. After lesions of one lateral funiculus in the lumbar cord the responses evoked by stimulation of the hindlimb contralateral to the lesion were reduced or abolished, leaving responses evoked by ipsilateral hindlimb afferents unaltered. Since both ipsi- and contralateral afferents generate responses in Golgi cells, the convergence from the two sides must occur supraspinally. It is difficult to reconcile these properties with any of the direct spinocerebellar pathways or spinoreticulocerebellar pathways that have been described. Instead, it is likely that the responses are evoked via the multimodal 'wide dynamic range' neurones of the anterolateral system. Golgi cell activity may thus be powerfully enhanced or depressed during arousal via the anterolateral system.  相似文献   
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Susceptibility to autoimmune insulin-dependent (type 1) diabetes mellitus is determined by a combination of environmental and genetic factors, which include variation in MHC genes on chromosome 6p21 (IDDM1) and the insulin gene on chromosome 11p15 (IDDM2). However, linkage to IDDM1 and IDDM2 cannot explain the clustering of type 1 diabetes in families, and a role for other genes is inferred. In the present report we describe linkage and association of type 1 diabetes to the CTLA-4 gene (cytotoxic T lymphocyte associated-4) on chromosome 2q33 (designated IDDM12). CTLA-4 is a strong candidate gene for T cell- mediated autoimmune disease because it encodes a T cell receptor that mediates T cell apoptosis and is a vital negative regulator of T cell activation. In addition, we provide supporting evidence that CTLA-4 is associated with susceptibility to Graves' disease, another organ- specific autoimmune disease.   相似文献   
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PURPOSE: Although black men with and without prostatic carcinoma in general have higher levels of prostate specific antigen (PSA) than other racial groups, the cause is unknown. Previous studies have shown that black men produce greater PSA per cc of benign gland volume. We determined whether prostatic inflammation varied by race and could account for the racial difference in PSA among prostate cancer patients. MATERIALS AND METHODS: Between April 1993 and February 1997, 238 patients underwent radical prostatectomy for clinically localized prostate cancer at Walter Reed Army Medical Center and whole mounted specimens were processed at the Armed Forces Institute of Pathology. Cases were reviewed by 2 pathologists (W. Z. and I. A. S.) blinded to clinical information, and scored for inflammation as 0--rare; 1--mild, 10 to 15 small foci; 2--moderate, greater than 15 foci with a large area or greater than 20 small foci; 3--marked, greater than 20 small foci with a large area, and 4--diffuse, multiple large areas. The extent of inflammation was correlated to pretreatment PSA and other variables. RESULTS: A total of 181 white and 57 black men were evaluated. Of the patients 28 were excluded from analysis due to prior hormonal therapy. The percentage of patients with inflammation scores from 1 to 4 was higher among white (113 of 161, 70.2%) than black (30 of 49, 61.2%) men but this difference was not significant (p = 0.299) and the extent of inflammation was not significantly related to racial variation in serum PSA. CONCLUSIONS: To our knowledge no significant racial difference exists in the extent of inflammatory infiltrate, and inflammation was not the etiology of the racial difference in serum PSA levels in this clinically localized prostate cancer cohort.  相似文献   
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葛根素的心血管系统药理作用及机理研究   总被引:27,自引:1,他引:27  
纵观近年来对葛根素在心血管系统药理作用及机理研究方面的进展发现,葛根素对心血管系统具有抗心律失常、降血压、扩张冠状动脉、抗心肌缺血、抗过氧化、抗缺血-再灌注损伤、影响血液动力学和血小板聚集、保护血管等作用。其临床应用前景良好,其药效机制研究及临床应用有待更深一步的探究。  相似文献   
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AIM: The aim of this article is to report a case of bilateral multiple impacted supernumerary teeth. A discussion of possible mechanisms of development is also presented along with a concise review of the literature. BACKGROUND: Supernumerary teeth occur in the context of various scenarios in the primary and the permanent dentition. Multiple supernumerary teeth are a rare finding especially in the absence of associated syndrome or disease. REPORT: A case of bilateral multiple impacted supernumerary teeth localized to the mandibular premolar region is reported. Some of the supernumerary teeth as well as the erupted premolars had persistent open apices. Coronal malformation of the right maxillary first premolar was another interesting finding. There was an absence of any concomitant disease. SUMMARY: The aforementioned combination of findings has not been reported previously. The anatomical, geometrical, and spatial relationships of supernumerary teeth with their erupted equivalents may shed light on some controversial aspects of the etiology.  相似文献   
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