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1.
Reactive oxygen species and human spermatozoa: physiology and pathology 总被引:20,自引:1,他引:19
The role of reactive oxygen species (ROS) in the pathophysiology of human sperm function has been emphasized in recent years. ROS production in semen has been associated with loss of sperm motility, decreased capacity for sperm–oocyte fusion and loss of fertility. There is a current presumption that the most prolific source of ROS in sperm suspensions is an NADPH oxidase located in leukocytes or in spermatozoa which produces superoxide which is further converted to peroxide by the action of superoxide dismutase. Hydrogen peroxide has been recognized as the most toxic oxidizing species for human spermatozoa, which are very sensitive to lipid peroxidation owing to the high content of polyunsaturated fatty acids in their plasma membrane, though this is not the sole mechanism by which sperm function might be impaired by ROS. Although the excessive production of ROS is detrimental to human spermatozoa, there is a growing body of evidence which suggests that ROS are also involved in the physiological control of some sperm functions. This review focuses on the nature and source of the ROS generated by human spermataozoa as well as their operational mechanisms and their effects, which may be detrimental or beneficial. 相似文献
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Quality of object relations versus interpersonal functioning as predictors of therapeutic alliance and psychotherapy outcome 总被引:1,自引:0,他引:1
W E Piper H F Azim A S Joyce M McCallum G W Nixon P S Segal 《The Journal of nervous and mental disease》1991,179(7):432-438
The purpose of the study was to compare an interview measure of quality of object relations to questionnaire and interview measures of recent interpersonal functioning with respect to the prediction of therapeutic alliance and psychotherapy outcome. The sample consisted of 64 patients who had received approximately 20 sessions of short-term individual psychotherapy within a controlled, clinical-trial investigation. Ratings of therapeutic alliance were provided independently by the patient and the therapist after each session. Outcome measures, which were provided by three sources (patient, therapist, and independent assessor), covered the areas of interpersonal functioning, psychiatric symptomatology, self-esteem, and life satisfaction. Quality of object relations, which characterizes the patient's lifelong pattern of relationships, was the best predictor. It was significantly related to patient-rated and therapist-rated therapeutic alliance and to patient improvement of both general symptomatology and specific target problems. The study also replicated previous studies that have reported significant relationships between therapeutic alliance and therapy outcome. The advantages of pretherapy predictors of therapy outcome, such as quality of object relations, are discussed. 相似文献
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研究不同微生物诱导家蝇幼虫表达的抗菌肽特性.用3种不同的病源菌通过针刺感染的方法诱导家蝇幼虫表达抗菌肽,通过Sephadex G25分离,用Hult mark改进法和抑菌圈测定法作抑菌试验,用毛细管电泳(CE)分析不同微生物诱导得到的抗菌肽样品差异,检测抗菌肽的热稳定性和酸碱耐受性.发现不同微生物诱导产生的家蝇抗菌肽具有广谱抑菌性,但不同样品对不同病源菌抑菌活性有差异,不同测定抑菌效果的方法对抑菌结果有影响,各种抗菌肽样品CE蛋白谱具有明显不同.抗菌肽样品都具有热稳定性和酸碱耐受性.说明不同微生物诱导产生的家蝇抗菌肽类型以及抗菌肽含量与诱导源有关,抗菌肽为家蝇幼虫体内固有成分,诱导增加了抗菌肽的表达量同时刺激新抗菌肽的产生.用志贺氏菌、金黄色葡萄球菌、鼠伤寒沙门氏菌诱导家蝇幼虫可产生较多含量高活性好的抗菌肽. 相似文献
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Nonsteroidal anti-inflammatory drug use and increased risk for peptic ulcer disease in elderly persons 总被引:25,自引:0,他引:25
M R Griffin J M Piper J R Daugherty M Snowden W A Ray 《Annals of internal medicine》1991,114(4):257-263
OBJECTIVE: To evaluate the relative risk for peptic ulcer disease that is associated with the use of nonaspirin nonsteroidal anti-inflammatory drugs. DESIGN: Nested case-control study. SETTING: Tennessee Medicaid program. PARTICIPANTS: Medicaid enrollees 65 years of age or older were included in the study. The 1415 case patients had been hospitalized for confirmed peptic ulcer disease at some point from 1984 through 1986. The 7063 control persons represented a stratified random sample of other Medicaid enrollees. MEASUREMENTS AND MAIN RESULTS: The estimated relative risk for the development of peptic ulcer disease among current users of nonaspirin nonsteroidal anti-inflammatory drugs, compared with that among nonusers, was 4.1 (95% CI, 3.5 to 4.7). For current users, the risk increased with increasing dose, from a relative risk of 2.8 (CI, 1.8 to 4.3) for the lowest to a relative risk of 8.0 (CI, 4.4 to 14.8) for the highest dose category. The risk was greatest in the first month of use (relative risk, 7.2; CI, 4.9 to 10.5). If the association is fully causal, 29% of peptic ulcers in the study sample resulted from the use of these drugs, and the excess risk associated with such use was 17.4 hospitalizations for ulcer disease per 1000 person-years of exposure. CONCLUSIONS: These data support other findings indicating that a clinically significant risk for serious ulcer disease is associated with the use of nonaspirin nonsteroidal anti-inflammatory drugs. The data show that this risk increases with dose and recency of use and that use of these drugs may be responsible for a large proportion of peptic ulcer disease among elderly persons. 相似文献
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