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51.
Retinoic acid stimulates neurite outgrowth in the amphibian spinal cord.   总被引:6,自引:0,他引:6  
There is increasing evidence that retinoic acid (RA), a vitamin A metabolite, plays a role in the development of the nervous system. Here we specifically test this notion by examining the effect of RA on neurite outgrowth from explanted segments of the axolotl spinal cord. We show that there is a threshold concentration in the region of 0.1-1 nM above which neurite outgrowth is stimulated 4-5 fold. Retinol, by contrast, only stimulated the migration of glial cells from the explants. Using HPLC we demonstrate that RA and retinol are present endogenously in the axolotl spinal cord. In addition, we have identified by immunocytochemistry with antipeptide antibodies the cells of the spinal cord that contain the binding proteins for RA (cellular RA-binding protein; CRABP) and retinol (cellular retinol-binding protein; CRBP). CRABP is found in the axons and CRBP is found in the ependyma and glial cells. These results provide strong evidence for a role for RA in the developing nervous system, and we propose a specific hypothesis involving CRBP, CRABP, retinol, and RA in the control of axon outgrowth in the spinal cord.  相似文献   
52.
The results of a screening programme for colorectal neoplasia in a high risk group using an immunochemical test for blood has been reported recently. This test is known as the faecal human haemoglobin (FHH) test. This paper reports the results of rescreening this group after an interval of 1-2 years. The FHH test was compared with a paper disc method. All individuals with positive tests were investigated and those with negative tests were offered investigation. The results confirm the value of the FHH test in screening a high risk group: 19 individuals in 1,153 participants were found to have a significant neoplasm (1.6%). The predictive value of the test for a significant neoplasm was 42%. A false negative rate of 2.6% was found, all lesions being benign. It appears to be more reliable than the paper disc method but the differences do not reach statistical significance. The FHH test is recommended for screening the general population over the age of 40 years, with rescreening annually.  相似文献   
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A comprehensive anatomic and radiographic analysis of the peribursal fat plane in 12 cadavers confirmed that the fat plane seen on radiographs represents extrasynovial fat lining the subacromial bursa and documented the anatomic relations of the bursa. A three-part retrospective clinical evaluation of rotator cuff tears, calcific tendinitis, and rheumatoid arthritis was performed. Two osteoradiologists blindly graded the appearance of the peribursal fat plane with the shoulder in external versus internal rotation in 21 patients with arthrographically intact rotator cuffs and 21 patients with disrupted rotator cuffs. The peribursal fat plane was seen better with disrupted rotator cuffs. The peribursal fat plane was seen better with the shoulder in internal rotation and was seen in 60% of control subjects but only 21% of patients with rotator cuff tears. Partial or complete obliteration of this fat plane is a sensitive (79%) but less specific (60%) indicator of rotator cuff tears. Obliteration of the peribursal fat plane by inflammatory processes in adjacent tissues, including calcific tendinitis and rheumatoid arthritis, occurred with a high frequency.  相似文献   
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We have recently treated a patient with an arteriovenous fistula that developed after a right internal jugular vein catheterization. The patient was found to have a pulsatile hematoma and a bruit five days after removal of a temporary pacemaker catheter. Digital subtraction arteriography documented a fistula between the right internal mammary artery and subclavian vein. The fistula was surgically repaired via the cervical route. To our knowledge, an arteriovenous fistula between the internal mammary artery and subclavian vein has not been previously described as a complication of a percutaneous internal jugular vein catheterization.  相似文献   
59.
Active surveillance for invasive meningococcal disease was conducted during 1986 and 1987 in six areas of the United States with a total population of approximately 34 million persons. The incidence of meningococcal disease was 1.3:10(5). The highest incidence of disease among the surveillance areas was in Los Angeles County (1.65:10(5). Neisseria meningitidis serogroups B and C caused about equal amounts of disease, which reflects a recent increase in the incidence of group C disease. Group C caused more than half of the cases of meningococcal disease in Los Angeles and Tennessee but less than one-third of the cases in Missouri and Oklahoma. Multilocus enzyme electrophoresis demonstrated that a group of closely related isolates of N. meningitidis was prevalent in Los Angeles during the surveillance period and was associated with an increased incidence of meningococcal disease there.  相似文献   
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ABSTRACT: This study obtained input from Australian student smokers approximately 15 years old, which may be useful in designing school-based smoking cessation programs. The sample was analyzed by previous quitting experience and intentions to quit. The order of preference for assistance options and incentives for quitting was similar across all groups: however, those who previously attempted to quit (previous quitters) and those who intended to quit (intenders) in the future were significantly more likely than non-quitters and non-intenders to find assistance options for quitting acceptable. The potential for saving money emerged as an important variable in convincing all groups of smokers not to smoke, and using personal willpower and cutting down slowly were identified as important in actual attempts to quit. The need for programs to be free and for friends to be supportive also was evident across all groups.  相似文献   
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