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排序方式: 共有400条查询结果,搜索用时 171 毫秒
41.
M Sun ; KH Chao ; LE Modahl ; G Leoung ; H Khayam-Bashi ; VL Ng ; EL Murphy 《Transfusion》1994,34(4):344-348
BACKGROUND: Asian Americans are generally underrepresented both as volunteer blood and bone marrow donors. STUDY DESIGN AND METHODS: To investigate the risk of transfusion transmission of viruses that is associated with increasing participation by Asian American donors, antibodies to human T-lymphotropic virus (HTLV), hepatitis C, and human immunodeficiency virus in Asian American volunteers recruited as potential bone marrow donors were measured. A total of 1354 Asian Americans were enrolled in the study, of whom 54 percent were Chinese, 26 percent Japanese, 9 percent Filipino, 4 percent Korean, 3 percent Indian, and 5 percent of other Asian or mixed Asian and other ethnicity. The majority of the study population was aged 20 through 49 and of high socioeconomic status, as indicated by education and income. Viral antibodies were measured with both screening enzyme-linked immunosorbent assays and supplemental testing, and polymerase chain reaction was used to resolve discrepant HTLV results. RESULTS: Confirmed seroprevalence rates for HTLV were 0.15 percent with one manufacturer's Western blot and 0.3 percent with the other; however, no sample was positive for HTLV types I or II in polymerase chain reaction. Confirmed seroprevalence to hepatitis C virus was 0.5 percent. No subject was seropositive for human immunodeficiency virus. CONCLUSION: On the basis of the moderate size and high education level of this study population, it is concluded that Asian American volunteer bone marrow donors do not pose a greater risk for transmission of HTLV type I or II, human immunodeficiency virus, or hepatitis C virus than does the average American blood donor. 相似文献
42.
True or sham plasma exchange was done weekly for 20 weeks in patients in two of the randomization groups in a prospective, blind clinical trial of experimental treatments for multiple sclerosis. Because patients could be randomized to receive sham plasma exchange and placebo medications, it was decided when the trial was designed that the use of fistulae, arteriovenous shunts, venous cutdowns, or other aggressive forms of venous access would not be permitted for any patient. Accordingly, patients judged to have inadequate superficial antecubital veins were ineligible for the trial. To date, only 13 (4.4%) of 294 patients considered for entry into the trial have been rejected on these grounds. In only 4 of the 93 patients undergoing exchange was it necessary to discontinue plasma exchange because of inadequate venous access. In 79.3 percent of the 1207 exchanges done in these patients, there were no problems of any kind with venous access. In 5.4 percent of these 1207 exchanges, it was necessary to terminate the procedure prematurely because of difficulties with patients' veins. Thus, the great majority of patients free of serious systemic illness (other than chronic progressive multiple sclerosis) can undergo weekly plasma exchange for up to 20 weeks using superficial antecubital veins without the need to resort to more invasive methods of venous access. 相似文献
43.
La nécrosectomie transgastrique semble être une alternative présentant peu de risques de traitement pour les patients gravement
atteints. Cependant, il manque à ce jour, une analyse des risques du procédé sur un nombre suffisant de patients; il est urgent
de procéder à des collectes de données multicentriques. Il s’agit de procédés endoscopiques complexes, qui nécessitent une
grande expérience, et le traitement de chaque patient devrait être planifié de fa?on interdisciplinaire en collaboration avec
le chirurgien. Ce procédé devrait par conséquent rester limité aux centres spécialisés. 相似文献
44.
Lars Budäus Markus Graefen Georg Salomon Hendrik Isbarn Giovanni Lughezzani Maxine Sun Felix KH Chun Thorsten Schlomm Thomas Steuber Alexander Haese Jens Koellermann Guido Sauter Margit Fisch Hans Heinzer Hartwig Huland Pierre I Karakiewicz 《International journal of urology》2010,17(10):862-868
Objective: To examine the rate of Gleason sum upgrading (GSU) from a sum of 6 to a Gleason sum of ≥7 in patients undergoing radical prostatectomy (RP), who fulfilled the recommendations for low dose rate brachytherapy (Gleason sum 6, prostate‐specific antigen ≤10 ng/mL, clinical stage ≤T2a and prostate volume ≤50 mL), and to test the performance of an existing nomogram for prediction of GSU in this specific cohort of patients. Methods: The analysis focused on 414 patients, who fulfilled the European Society for Therapeutic Radiation and Oncology and American Brachytherapy Society criteria for low dose rate brachytherapy (LD‐BT) and underwent a 10‐core prostate biopsy followed by RP. The rate of GSU was tabulated and the ability of available clinical and pathological parameters for predicting GSU was tested. Finally, the performance of an existing GSU nomogram was explored. Results: The overall rate of GSU was 35.5%. When applied to LD‐BT candidates, the existing nomogram was 65.8% accurate versus 70.8% for the new nomogram. In decision curve analysis tests, the new nomogram fared substantially better than the assumption that no patient is upgraded and better than the existing nomogram. Conclusions: GSU represents an important issue in LD‐BT candidates. The new nomogram might improve patient selection for LD‐BT and cancer control outcome by excluding patients with an elevated probability of GSU. 相似文献
45.
HT Syyong HHC Yang G Trinh C Cheung KH Kuo C van Breemen 《British journal of pharmacology》2009,156(4):587-600
Background and purpose:
Uridine 5''-triphosphate (UTP) is a potent vasoconstrictor of cerebral arteries and induces Ca2+ waves in vascular smooth muscle cells (VSMCs). This study aimed to determine the mechanisms underlying UTP-induced Ca2+ waves in VSMCs of the rat basilar artery.Experimental approach:
Isometric force and intracellular Ca2+ ([Ca2+]i) were measured in endothelium-denuded rat basilar artery using wire myography and confocal microscopy respectively.Key results:
Uridine 5''-triphosphate (0.1–1000 µmol·L−1) concentration-dependently induced tonic contraction (pEC50 = 4.34 ± 0.13), associated with sustained repetitive oscillations in [Ca2+]i propagating along the length of the VSMCs as asynchronized Ca2+ waves. Inhibition of Ca2+ reuptake in sarcoplasmic reticulum (SR) by cyclopiazonic acid abolished the Ca2+ waves and resulted in a dramatic drop in tonic contraction. Nifedipine reduced the frequency of Ca2+ waves by 40% and tonic contraction by 52%, and the nifedipine-insensitive component was abolished by SKF-96365, an inhibitor of receptor- and store-operated channels, and KB-R7943, an inhibitor of reverse-mode Na+/Ca2+ exchange. Ongoing Ca2+ waves and tonic contraction were also abolished after blockade of inositol-1,4,5-triphosphate-sensitive receptors by 2-aminoethoxydiphenylborate, but not by high concentrations of ryanodine or tetracaine. However, depletion of ryanodine-sensitive SR Ca2+ stores prior to UTP stimulation prevented Ca2+ waves.Conclusions and implications:
Uridine 5''-triphosphate-induced Ca2+ waves may underlie tonic contraction and appear to be produced by repetitive cycles of regenerative Ca2+ release from the SR through inositol-1,4,5-triphosphate-sensitive receptors. Maintenance of Ca2+ waves requires SR Ca2+ reuptake from Ca2+ entry across the plasma membrane via L-type Ca2+ channels, receptor- and store-operated channels, and reverse-mode Na+/Ca2+ exchange. 相似文献46.
Denise A Castronovo Kenneth KH Chui Elena N Naumova 《Environmental health : a global access science source》2009,8(1):61
Background
Epidemiologic studies are often confounded by the human and environmental interactions that are complex and dynamic spatio-temporal processes. Hence, it is difficult to discover nuances in the data and generate pertinent hypotheses. Dynamic mapping, a method to simultaneously visualize temporal and spatial information, was introduced to elucidate such complexities. A conceptual framework for dynamic mapping regarding principles and implementation methods was proposed. 相似文献47.
人工关节置换术是矫正关节畸形、解除关节疼痛、重建关节功能的主要手段。多年来 ,人工全髋、全膝皆以聚乙烯为关节形成表面 ,随着人工关节置换的广泛开展 ,聚乙烯磨损问题越来越引起人们的关注。聚乙烯磨损及其产生的碎屑和磨损颗粒所引发的生物学反应及导致的骨吸收、骨溶解 ,是造成假体松动、人工关节翻修的主要原因[1,2 ] 。与人工髋关节的球洞几何形态相比 ,人工膝关节的几何形态要不吻合的多 ,胫骨假体表面常承受较大的接触应力 ,较易产生磨损[2 ,3 ] ,理论上关节形成表面越吻合 ,聚乙烯磨损越少 ,不同的胫股关节吻合性 ,对假体磨损产… 相似文献
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