Effects of Volatile Anesthetics on Glutamate Transporter, Excitatory Amino Acid Transporter Type 3: The Role of Protein Kinase C

Background: Glutamate transporters play an important role in maintaining extracellular glutamate homeostasis. The authors studied the effects of volatile anesthetics on one type of glutamate transporters, excitatory amino acid transporter type 3 (EAAT3), and the role of protein kinase C in mediating these effects.

Methods: Excitatory amino acid transporter type 3 was expressed in Xenopus oocytes by injection of EAAT3 mRNA. Using two-electrode voltage clamp, membrane currents were recorded before, during, and after application of l-glutamate. Responses were quantified by integrating the current trace and are reported as microcoulombs. Data are mean +/- SEM.

Results: l-Glutamate-induced responses were increased gradually with the increased concentrations of isoflurane, a volatile anesthetic. At 0.52 and 0.70 mm isoflurane, the inward current was significantly increased compared with control. Isoflurane (0.70 mm) significantly increased Vmax (maximum velocity) (3.6 +/- 0.4 to 5.1 +/- 0.4 [mu]C;P < 0.05) but not Km (Michoelis-Menten Constant) (55.4 +/- 17.0 vs. 61.7 +/- 13.6 [mu]m;P > 0.05) of EAAT3 for glutamate compared with control. Treatment of the oocytes with phorbol-12-myrisate-13-acetate, a protein kinase C activator, caused a significant increase in transporter current (1.7 +/- 0.2 to 2.5 +/- 0.2 [mu]C;P < 0.05). Responses in the presence of the combination of phorbol-12-myrisate-13-acetate and volatile anesthetics (isoflurane, halothane, or sevoflurane) were not greater than those when volatile anesthetic was present alone. Oocytes pretreated with any of the three protein kinase C inhibitors alone (chelerythrine, staurosporine, or calphostin C) did not affect basal transporter current. Although chelerythrine did not change the anesthetic effects on the activity of EAAT3, staurosporine or calphostin C abolished the anesthetic-induced increase of EAAT3 activity.     

Oxygenation of Liver Transplants as a Predictor of Success

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大剂量鲁米那钠加安定静脉滴入治疗新生儿破伤风

近年来新生儿破伤风有增加趋势,死亡率高,我院子1985年起,试用大剂量鲁米那钠加安定静脉滴入,治疗住院病儿52例,疗效满意,现报告如下: 临床资料治疗组52例,男36例,女16例,平均发病日龄9.19天。对照组123例,男91例,女32例,平均发病日龄9.75天。诊断标准参照教科书。痉挛强度用计分法:单纯牙关紧闭为1分,牙关紧闭+角弓反张+刺激性痉挛为2分,频繁自发性痉挛为3分,持久而严重的自发性痉挛+紫绀或呼吸暂停为4分。     

FDA审查Pfizer改变Norvasc标签的要求

美国FDA的心血管肾脏药物咨询委员会将在4月5日审查Pfizer公司请求修改Norvasc（amlodipine besylate，氨氯地平）（Ⅰ）的商标资料，其中包括具有里程碑意义的2002年ALLHAT研究中减少冠心病发作危险的结果。这项降压降脂预防心脏病发作试验共有42000多名高危的高血压病人参加。     

Beneficial Effects of Short-term Vasopressin Infusion during Severe Septic Shock

Background: Septic shock is associated with vasopressin deficiency and a hypersensitivity to its exogenous administration. The goal of the current study was to determine whether short-term vasopressin infusion in patients experiencing severe septic shock has a vasopressor sparing effect while maintaining hemodynamic stability and adequate end-organ perfusion.

Methods: Patients experiencing septic shock that required high-dose vasopressor support were randomized to a double-blinded 4-h infusion of either norepinephrine (n = 11) or vasopressin (n = 13), and open-label vasopressors were titrated to maintain blood pressure. To assess end-organ perfusion, urine output and creatinine clearance, gastric mucosal carbon dioxide tension, and electrocardiogram ST segment position were measured.

Results: Patients randomized to norepinephrine went from a median prestudy norepinephrine infusion of 20.0 [mu]g/min to a blinded infusion of 17.0 [mu]g/min at 4 h, whereas those randomized to vasopressin went from a median prestudy norepinephrine infusion of 25.0 [mu]g/min to 5.3 [mu]g/min at 4 h (P < 0.001). Mean arterial pressure and cardiac index were maintained in both groups. Urine output did not change in the norepinephrine group (median, 25 to 15 ml/h) but increased substantially in the vasopressin group (median, 32.5 to 65 ml/h;P < 0.05). Similarly, creatinine clearance did not change in the norepinephrine group but increased by 75% in the vasopressin group (P < 0.05). Gastric mucosal carbon dioxide tension and electrocardiogram ST segments did not change significantly in either group.     

福建省室内蜚蠊调查研究

对福建省室内蜚蠊的调查结果,已发现四科、五属、十五种(已定的九种,未定的六1种).并就蜚蠊的种群分布,季节消长、活动规律、生态习性和蜚蠊与疾病关系以及诱捕、杀灭方法等进行了较系统的研究为进一步研究、防制蜚蠊提供科学依据。     

Sinoatrial Node Electrogram Studies in Patients with Sick Sinus Syndrome

Sinoatrial node electrogram (SNE) was recorded successfully in recent years, using transvenous electrode catheter. Via SNE and intratrialelectrogram (IEG), one could measure sinoatrial conduction time(SACT) directly, observe sinoatrial node (SN) potential changes in cadiac cycles, diagnose some sinus arrhythmias which couldn't be confirmed by surface ECG. All these could offer accurate evidence for differential diagnosis of sick sinus syndrome (SSS). The authors recommend a modified method for the location of the electrode catheter, by which one can increase success rate of obtaining stable SNE. Using this method, the authors recorded SNE in 10 cases with SSS successfully.     

RESEARCH ON A REAL-TIME CONTROL SYSTEM OF LOW POWER DISSIPATION FOR CONTINUOUS CYCLIC PERITONEAL DIALYSIS(CCPD) CYCLER

FOREWORDPeritonealdialysisrepresentssoluteandfluidexchangemainlybetweenperitonealcapillarybloodanddialysissolutionintheperitonealcavity'CombinedwithhemodialySisandrenaltransplantation,peritonealdialysisisusedmainlyforthetreatmentofrenalfailure,particularlyforchronicfailure'In1976,Prof'Popovichdevelopedcontinuousambulatoryperitonealdialysis(CAPD)basingontheconceptofcontinuousequilibrationdialysis('1'Fromthenon,peritonealdialysisfounditsclinicaluse'Continuouscyclicperitonealdialysis(CCPD…     

日本YMS公司推出Sierra磁共振成象装置

日本东京Yokogawa医用仪器公司已宣称与美国通用电气公司,联合开发成功1.5Tesla超导,双床磁共振成象装置Sierra。 Sierra的设计是减少空间,提供的优点是1.5Tesla机器仅需要中磁场强度型号机器相同的空间要求,结构较紧凑以致于可选用GE公司的活动磁场屏蔽进行屏蔽。 Sierra装备有快速扫描装置,它比传统型号快16倍的速度进行旋转诊断,而不损失图