The effects of antioxidant supplementation during Percoll preparation on human sperm DNA integrity

The integrity of sperm DNA is crucial for the maintenance of genetic health. A major source of damage is reactive oxygen species (ROS) generation; therefore, antioxidants may afford protection to sperm DNA. The objectives of the study were, first, to measure the effects of antioxidant supplementation in vitro on endogenous DNA damage in spermatozoa using the single cell gel electrophoresis (comet) assay and, second, to assess the effect of antioxidant supplementation given prior to X-ray irradiation on induced DNA damage. Spermatozoa from 150 patients were prepared by Percoll centrifugation in the presence of ascorbic acid (300, 600 microM), alpha tocopherol (30, 60 microM), urate (200, 400 microM), or acetyl cysteine (5, 10 microM). DNA damage was induced by 30 Gy X-irradiation. DNA strand breakage was measured using the comet assay. Sperm DNA was protected from DNA damage by ascorbic acid (600 microM), alpha tocopherol (30 and 60 microM) and urate (400 microM). These antioxidants provided protection from subsequent DNA damage by X-ray irradiation. In contrast, acetyl cysteine or ascorbate and alpha tocopherol together induced further DNA damage. Supplementation in vitro with the antioxidants ascorbate, urate and alpha tocopherol separately has beneficial effects for sperm DNA integrity.      

氯沙坦减少高血压患者终点事件的研究(LIFE STUDY)

标　　题　应用ＡＴⅡ受体拮抗剂抗高血压治疗作　　者　ＫｊｅｌｄｓｅｎＳＥ,ＯｍｖｉｋＰ.　　参考文献　ＴｉｄｓｓｋｒＮｏｒＬａｅｇｅｆｏｒｅｎ,1996,116:504～507研究疾病　高血压病。目　　的　评估氯沙坦对心血管死亡率及非致死性心肌梗死和非脑卒中发生率的影响,同时评估该药对充血性心力衰竭或心绞痛所致的总死亡率和住院率的影响,以及长期应用氯沙坦对发生新诊断糖尿病的影响。设　　计　随机、三盲、对照研究。病人资料　8300例年龄55～80岁、收缩压在160～200ｍｍＨｇ、舒张压在95～115ｍｍＨｇ的高血压患者,ＥＣＧ上有左室…     

l-Baclofen-sensitive GABAB binding sites in the medial vestibular nucleus localized by immunocytochemistry

l-Baclofen-sensitive GABA_B binding sites in the medial vestibular nucleus (MVN) were identified immunocytochemically and visualized ultrastructurally inl-baclofen-preinjected rats and monkeys, using a mouse monoclonal antibody with specificity for the p-chlorophenyl moiety of baclofen. Saline-preinjected animals showed no immunostain. In drug-injected animals, there was evidence for both pre- and postsynaptic GABAergic inhibition in MVN mediated by GABA_B receptors. These neural elements could be utilized in control of velocity storage in the vestibulo-ocular reflex.     

Interobserver variation in the interpretation of abdominal radiographs

A total of 140 sets of abdominal radiographs were reviewed independently by four qualified diagnostic radiologists. The degree of interobserver agreement was determined by calculating kappa values for 19 commonly used radiographic signs and diagnoses. There was fair to excellent interobserver agreement for 11 signs and diagnoses and poor agreement for the remaining eight. The signs and diagnoses for which agreement is poor cannot be considered reliable and include particularly large bowel obstruction and nonspecific gas pattern.