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排序方式: 共有5073条查询结果,搜索用时 343 毫秒
41.
Nuclear medicine and thyroid cancer 总被引:1,自引:0,他引:1
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Gerald Gartlehner Suzanne L West Kathleen N Lohr Leila Kahwati Jana G Johnson Russell P Harris Lynn Whitener Christiane E Voisin Sonya Sutton 《International journal for quality in health care》2004,16(5):399-406
BACKGROUND: An important concern for developers of clinical practice guidelines is how best to determine when guidelines require updating to ensure they remain current and evidence based. Because of the high costs associated with updating guidelines, recent attention has focused on approaches that can reliably assess the extent of updating required. Recently, Shekelle and colleagues proposed a model of limited literature searches with modest expert involvement as a way to reduce the cost and time requirements for assessing whether a guideline needs updating. METHODS: The main objective of this study was to compare the Shekelle et al. assessment model (review approach) and a conventional process using typical systematic review methods (traditional approach) in terms of comprehensiveness and effort. We modeled the review approach on that by Shekelle and colleagues but refined it iteratively over three phases to achieve greater efficiency. Using both methods independently, we assessed the need to update six topics from the 1996 Guide to Clinical Preventive Services from the US Preventive Services Task Force. Main outcomes included completeness of study identification, importance of missed studies and the effort involved. RESULTS: Although the review approach identified fewer eligible studies than the traditional approach, none of the studies missed was rated as important by task force members acting as liaisons to the project with respect to whether the topic required an update. On average, the review approach produced substantially fewer citations to review than the traditional approach. The effort involved and potential time saving depended largely on the scope of the topic. CONCLUSIONS: The revised review approach provides an efficient and acceptable method for judging whether a guideline requires updating. 相似文献
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Prabhat Kumar Samanta Indranil Manna Kuladip Jana 《Reproductive Medicine and Biology》2006,5(2):145-153
In order to investigate the ameliorative potential of L-ascorbic acid on intensive swimming exercise induced testicular oxidative
stress, 18 Wistar male rats (age: 3 months, weight: 127.5 ± 5.3 g) were randomly divided into the following groups: (i) control
group (CG,n = 6); (ii) experimental group (EG,n = 6); and (iii) supplemented group (SG,n = 6). An exercise protocol of 3 h swimming per day, five days per week was followed for 6 weeks in EG and SG with no exercise
in CG. In SG, L-ascorbic acid was supplied orally at a dose of 25-mg/kg of bodyweight each day for 6 weeks. A significant
decrease (P < 0.05) was noted in paired testicular weights, epididymal sperm count, testicular Δ5, 3β-hydroxyseroid dehydrogenase, 17β-hydroxyseroid dehydrogenase, plasma levels of testosterone luteinizing hormone, follicle
stimulating hormone, prolactin, the numbers of preleptotine spermatocytes, midpachytene spermatocytes and stage 7 spermatids
of stage VII seminiferous epithelium cycle in EG when compared with CG. A significant elevation (P < 0.05) in plasma corticosterone and testicular content of malondialdehyde along with a significant reduction (P < 0.05) in glutathione, ascorbic acid, α-tocopherol, superoxide dismutase, catalase and glutathione-peroxidase, and glutathione-S-transferase
were noted in testes of EG compared with CG. No significant change was noted in final bodyweight or numbers of spermatogonia-A
among the groups. Furthermore, L-ascorbic acid supplementation restored the above parameters to the control level.
Conclusion It can be concluded that intensive swimming exercise induced oxidative stress causes dysfunctions in the male reproductive
system, which can be protected by L-ascorbic acid. 相似文献
44.
Mutations in CTC1 lead to the telomere syndromes Coats Plus and dyskeratosis congenita (DC), but the molecular mechanisms involved remain unknown. CTC1 forms with STN1 and TEN1 a trimeric complex termed CST, which binds ssDNA, promotes telomere DNA synthesis, and inhibits telomerase-mediated telomere elongation. Here we identify CTC1 disease mutations that disrupt CST complex formation, the physical interaction with DNA polymerase α-primase (polα-primase), telomeric ssDNA binding in vitro, accumulation in the nucleus, and/or telomere association in vivo. While having diverse molecular defects, CTC1 mutations commonly lead to the accumulation of internal single-stranded gaps of telomeric DNA, suggesting telomere DNA replication defects as a primary cause of the disease. Strikingly, mutations in CTC1 may also unleash telomerase repression and telomere length control. Hence, the telomere defect initiated by CTC1 mutations is distinct from the telomerase insufficiencies seen in classical forms of telomere syndromes, which cause short telomeres due to reduced maintenance of distal telomeric ends by telomerase. Our analysis provides molecular evidence that CST collaborates with DNA polα-primase to promote faithful telomere DNA replication. 相似文献
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Jill M. Pulley Rebecca N. Jerome Gordon R. Bernard Jana K. Shirey-Rice Yaomin Xu Consuelo H. Wilkins 《Journal of the National Medical Association》2021,113(2):187-194
ObjectiveWe conducted a phenotype-wide association study (PheWAS) to compare diagnoses among Blacks with those of Whites in one health center in Tennessee using data from 1,883,369 patients.MethodsWe used our deidentified EHR, the Synthetic Derivative, to assess risk of diagnoses associated with Black as compared with White race using Firth logistic regression with covariates including age, sex, and density of clinical encounters.ResultsThere were anchoring associations in both directions, including the highest increased risk for Blacks of having sickle cell anemia, and strongest decreased risk of basal cell carcinoma. Results included established areas of disparity and many novel associations.ConclusionsPheWAS is a viable tool for calculating risk associated with any biomarker. The current analysis provide a new approach to generating hypotheses and understanding the breadth of health disparities. Future analyses will further explore causality, risk factors, and potential confounders not accounted for here. 相似文献
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Prospective study of signalling pathways in myeloma bone disease with regard to activity of the disease,extent of skeletal involvement and correlation to bone turnover markers 下载免费PDF全文
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