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51.
Dehydroepiandrosterone and dehydroepiandrosterone sulfate are steroids which may be associated with the development of breast cancer. To examine the association between serum levels of dehydroepiandrosterone and dehydroepiandrosterone sulfate and the risk of developing premenopausal breast cancer, we measured hormone levels in 15 women who donated blood to a community-based serum bank in 1974 and who subsequently developed premenopausal breast cancer and in 29 matched controls from the same group of volunteers. The mean serum level of dehydroepiandrosterone among cases was 10% lower than among controls. The risk of developing breast cancer for women in the highest tertile compared with the lowest tertile of serum dehydroepiandrosterone was 0.40 with a suggestion of a dose-response trend with increasing levels. No consistent association between dehydroepiandrosterone sulfate and the risk of premenopausal breast cancer was evident. In contrast to postmenopausal breast cancer, a protective effect of dehydroepiandrosterone against premenopausal breast cancer is suggested, but because of the small sample size, the results of this study need to be replicated by others.  相似文献   
52.
OBJECTIVE: The purpose is to define factors influencing long-term patency of the internal thoracic artery (ITA) to optimize the operative strategy. METHODS: 1482 left internal thoracic artery (LITA) and 636 right internal thoracic artery (RITA) symptom-directed angiograms were studied in 1434 patients. Data were prospectively collected from patients who had primary coronary artery bypass surgery during the period 1982-2002. The mean age of patients was 59 years; 85% were male. The mean period from operation to re-angiogram was 80 months. LITA was grafted to left anterior descending coronary artery (LAD) in 82% of cases, RITA to right coronary artery (RCA) in 40% and circumflex artery in 35% of cases. Graft failure was defined as > or =80% stenosis. RESULTS: 96.3% of LITA and 88.1% of RITA grafts were patent. No patient variables were significantly associated with graft patency (age, gender, diabetes, hypertension, LVEF, NYHA, AMI). Target coronary artery was associated with patency of both LITA and RITA grafts with maximum patency when grafted to LAD (P = 0.02) RITA had the worst patency to RCA, patency for the left system was identical to LITA. Proximal anastomosis to aorta (free RITA) had significantly better patency when compared with in situ RITA to RCA system (P = 0.005) while similar patency when grafted to left system. ITA diameter and target artery diameter were not associated with graft patency. Recent operations had better RITA patency (P = 0.03). The interval from operation to angiogram was not associated with ITA patency (96% patency for LITA and 88% patency for RITA, remained stable when studied at <1, 1-4, 5-9, 10-14 and >15 years). CONCLUSIONS: Even in a patient cohort that had adverse symptoms, excellent LITA and RITA patency was achieved which almost remained constant through all time intervals studied.  相似文献   
53.
This study provides an overview of the papers emanating from the experimental trial that evaluated a new cognitive rehabilitation program in older adults who were experiencing normal cognitive decline. The main features of the design are summarized, along with evidence that the training produced long-lasting improvement in memory performance, goal management, and psychosocial status. The benefits were attributed to several factors, including the program's emphasis on techniques that promoted efficient strategic processing. Limitations of the program and directions for future research are discussed.  相似文献   
54.
Preschool children with autism and their normally developing peers were compared on the Stanford-Binet IV and Preschool Language Scale before and after 1 school year. Both measures showed that although the children with autism functioned at a lower level than their normally developing peers, the children with autism had narrowed this gap after treatment, making a nearly 19-point increase in IQ and an 8-point gain in language quotient. The IQ measure remained stable for the normally developing peers while their language showed a 7.73-point increase. The data support the notion that young children with autism can make very significant developmental gains.Special thanks to the parents and the children who participated in this study. Thanks also to Michael Alessandri, Jean Burton, David Celiberti, Nancy Gera-Moglia, Anne Nathan, and Lisa Kamean who assisted in the data collection process. We appreciate the cooperation of Alicia MacWright and Leisa Tomchek who taught two of the classes from which participants were drawn.  相似文献   
55.
The uptake, metabolism, and cellular distribution of 3H-docosahexaenoic acid (3H-22:6) in the frog retina during in vitro incubation were studied. An initial diffuse labeling throughout the retina was detected by autoradiography and was followed by an active steady increase in labeled photoreceptor cells. After 6 hr of incubation, 92% of the label was concentrated in photoreceptor cells. Among these cells, 435-rods (green rods) labeled heavily and showed two to three times higher uptake than the 502-rods (red rods). Cone uptake labeling was the lowest, showing negligible labeling throughout the cytoplasm. However, oil droplets of the 575-cones actively concentrated 22:6. The high uptake of 3H-22:6 by photoreceptor cells was followed by its rapid esterification into phospholipids. After 6 hr of labeling, only 5% of the radioactivity in the retina was free 22:6, whereas 88% was esterified into phospholipids. The remaining 22:6 was distributed equally in triacylglycerols (TAGs) and diacylglycerols. When 3H-22:6 (0.11 microM) of high specific activity was used, early incubation times showed phosphatidylinositol (PI) labeling to be of the same order of magnitude or greater than that of phosphatidylcholine (PC) or phosphatidylethanolamine (PE). Although the amount of endogenous 22:6 esterified into PI accounted for less than 2% of the 22:6 in retinal phospholipids, 27% of 3H-22:6 labeling was recovered in this phospholipid. When 14C-22:6 at a final concentration of 70 microM was used, a different profile of lipid labeling was observed. Forty percent of the labeling remained in the free fatty acid pool, followed by TAG (24%), PC (14%), and PE (12%). PI showed the smallest increase in picomoles of 14C-22:6 incorporated, when compared with 3H-22:6. In conclusion, a selective and differential uptake of 3H-22:6 by photoreceptor cells is coupled to its active utilization for phospholipid biosynthesis, mainly that of PC, PE, and PI. The differential uptake of 3H-22:6 among photoreceptor cells may reflect involvement of this fatty acid in cell-specific functions.  相似文献   
56.
The effect of age on binding of MK-801 in the cat visual cortex.   总被引:3,自引:0,他引:3  
We have examined the effect of age on the binding of (+)-5-methyl-10,11-dihydro-5H-dibenzo[a,d]-cyclohepten-5,10-imine maleate (MK-801) in the cat visual cortex. We hypothesized that this binding might change with age because: (1) MK-801 binds to a site associated with the N-methyl-D-aspartate (NMDA) receptor; (2) the NMDA receptor complex has been implicated in neural plasticity; (3) plasticity in the cat visual cortex is age dependent. We used standard receptor binding techniques to measure MK-801 binding in membrane homogenates in cats aged 7 days (d), 21 d, 43 d, 83 d, 7-8 months (mo) and over 2 years. Glutamate (100 microM), glycine (30 microM) and spermidine (20 microM) were used to enhance binding. We found that MK-801 binding is maximal at about 6 weeks of age, decreases slightly by 83 days and then decreases more dramatically in adults. Saturation analysis showed that the of binding with age resulted from variation in number of binding sites and not from variation in affinity. The ability of Mg2+ to inhibit MK-801 binding did not change with age. Dark rearing did not alter the development of MK-801 binding sites.  相似文献   
57.
Journal of Prevention - The major issues involved in the design and implementation of effective school screening programs are addressed, using data from a longitudinal study following over 500...  相似文献   
58.
SUMMARY Disease-modifying antirheumatic drugs are used in virtually all patients with established rheumatoid arthritis. An increasingly large number of new drugs is now available. Furthermore, old therapies are being used in novel ways. Treatment is now begun earlier and patients are rarely left untreated. This report summarises recent developments regarding the drugs currently in use and those that may be available in the near future.  相似文献   
59.
The metabolism of 8-methyl-8-azabicyclo- 3,2,1]octan-3-yl 3,5-dichlorobenzoate (MDL 72,222) was studied in the dog and monkey. Four urinary metabolites were detected by HPLC, HPLC/MS, and GC/MS, and were identified by comparison to authentic standards. The major metabolite in the dog, approximately 41% of the administered dose excreted between 0 and 120 hr, was the MDL 72,222-N-oxide. On the other hand, the major metabolite in the monkey was the glycine conjugate of 3,5-dichlorobenzoic acid (greater than 56% of the dose). Seven percent of the dose in the monkey urine was free 3,5-dichlorobenzoic acid. N-Desmethyl MDL 72,222 was present at 2.5 and 1% in the dog and monkey, respectively. Very little (less than 1%) of the parent compound was found in urine. The major pathways of metabolism of MDL 72,222 are N-oxidation, N-demethylation, ester hydrolysis, and amino acid conjugation.  相似文献   
60.
Purpose: To describe an educational computer aided instruction program dealing with diagnosis and classification of facial fractures. Methods: A program was created for use on Macintosh computers using a graphic presentation package. This program allows for the display of high resolution digitized radiographic images and illustrations, along with integrated voice and text information. Users can interact with the program to review complex concepts or study additional cases. Case material was obtained from selected high quality plain radiographs and computed tomography (CT) scans obtained in the trauma center of one institution, and was scanned on a high resolution digital scanner with image parameters optimized for viewing on the Macintosh high resolution color monitor. Results: The program has been installed in the computer aided instructional laboratories or trauma centers at The University of Texas Health Science Center, Houston; The University of Alabama, Birmingham; Emory University School of Medicine, Atlanta, Georgia; and The University of North Carolina, Chapel Hill. The program is available to radiology residents and medical students rotating on the trauma radiology services at these institutions. Completion of the program requires 30–45 minutes. Conclusion: Based on our initial experience, the program has been used by residents in the training programs of all institutions with favorable results.  相似文献   
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