Glutamate hypothesis in schizophrenia

Schizophrenia is a chronic and severe psychiatric disorder that has profound impact on an individual’s life and on society. Thus, developing more effective therapeutic interventions is essential. Over the past quarter‐century, an abundance of evidence from pharmacologic challenges, post‐mortem studies, brain imaging, and genetic studies supports the role of glutamatergic dysregulation in the pathophysiology of schizophrenia, and the results of recent randomized clinical trials based on this evidence have yielded promising results. In this article, we review the evidence that alterations in glutamatergic neurotransmission, especially focusing on the N‐methyl‐d ‐aspartate receptor (NMDAR) function, may be a critical causative feature of schizophrenia, how this contributes to pathologic circuit function in the brain, and how these insights are revealing whole new avenues for treatment development that could reduce treatment‐resistant symptoms, which account for persistent disability.     

The effect of cephalothin prophylaxis on postoperative ventriculoperitoneal shunt infections.

Postoperative infection is an important complication after insertion of a ventriculoperitoneal (VP) shunt in children with hydrocephalus. A randomized double-blind placebo-controlled study was performed to determine the efficacy of cephalothin in preventing postoperative shunt infection. Sixty-three children who presented for elective VP shunt insertion between January 1982 and December 1985 and who did not have a history of shunt infections were randomly assigned to receive four doses of prophylactic cephalothin, 25 mg/kg (32 patients), or of a multivitamin placebo (31 patients). Postoperative infection developed in 6% of the treatment group, compared with 10% of the placebo group, a difference that was not statistically significant, although a clinical significance may have been masked by the small sample size. A large multicentre trial is needed to determine the efficacy of antibiotic prophylaxis in reducing the incidence of postoperative VP shunt infections.     

Costs and benefits of routine follow-up after curative treatment for endometrial cancer

OBJECTIVE: To examine the costs of routine outpatient follow-up after curative treatment of endometrial cancer, and to determine whether this leads to early detection of recurrence or survival. The impact of specific disease characteristics on survival is examined. DESIGN: Retrospective chart review, and calculation of costs. SETTING: Ottawa Regional Cancer Centre-Civic Division (ORCC-C). PATIENTS: All 432 patients referred to the ORCC-C with endometrial cancer between 1982 and 1991 who received treatment with curative intent and who continued with routine follow-up. RESULTS: Cancer recurred in 50 patients (11.57%). There was no statistically significant difference in overall survival between patients with symptomatic and asymptomatic recurrences, or between those with recurrences detected during routine follow-up visits or in the interval between routine visits. Of 4830 Papanicolaou (Pap) smears performed routinely, cancer was detected in 6 cases. The mean cost of the routine follow-up procedures for each patient with a recurrence was $19,200. CONCLUSION: Intensive follow-up of women with endometrial cancer does not result in improved survival. A prospective randomized study is warranted to evaluate other potential benefits of follow-up, such as improved quality of life or decreased morbidity. There is no economic or clinical justification for the routine use of the Pap smear in the follow-up of patients with endometrial cancer. The potential benefits of routine follow-up in endometrial cancer and other types of cancer with favourable prognoses warrant critical evaluation.     

创伤后迟发性脑肿胀的临床特点与治疗

目的 探讨创伤后迟发性脑肿胀的临床特点、发病机制与治疗。方法 回顾性分析1998年1月～2005年6月年收治的17例迟发性脑肿胀患者的临床特点和救治情况。结果 所有颅脑损伤患者采用保守治疗后均有好转，但于伤后5-10d出现恶化，CT复查有脑肿胀，经加强综合脱水等治疗后16例治愈，1例死亡。结论 迟发性脑肿胀好发于对冲性额、颞叶挫裂伤伴明显蛛网膜下腔出血、硬膜下薄层血肿及早期CT有脑肿胀者。其发病机制可能与创伤后的迟发性脑血管痉挛、微循环障碍、静脉回流障碍及甘露醇作用下降等因素有关。此类患者病情隐蔽性强，应加强观察、积极行CT复查，如能早期明确诊断，保守治疗多数效果良好。     

Enteroviruses in recreational waters of Northern Ireland.

Virus surveillance of Northern Ireland recreational waters, between April 1986 and May 1989 demonstrated widespread enteroviral contamination of coastal and inland waters. In 1986, enteroviruses were detected in 4 of 46 (8.7%) water samples, collected from 6 coastal bathing waters. In 1987, 49 of 107 (45.8%) samples, from 16 coastal bathing waters, yielded enteroviruses; 33 of the enterovirus positive samples passed one or both of the coliform standards outlined by the European Economic Community (EEC) bathing water directive (76/160/EEC). Enteroviruses were also detected in 33 of 39 (84.6%) samples tested from 3 inland recreational waters.     

Retrorenal colon: implications for percutaneous diskectomy

It has been recommended that computed tomography (CT) with the patient prone be performed in every patient undergoing percutaneous diskectomy; this would enable detection of a retrorenal location of the colon, which could interfere with the percutaneous procedure. In this evaluation of 346 prone CT studies, only one patient (0.29%) was found to have retrorenal or retropsoas bowel that would have been perforated at diskectomy. Because of this extremely low prevalence, the performance of prone CT in every patient undergoing percutaneous lumbar diskectomy is not believed to be necessary.     

Characteristics of chloride-dependent incorporation of glutamate into brain membranes argue against a receptor binding site

Although membrane sites from brain, labelled with [3H]glutamate (Glu) under sodium-free conditions, are thought to represent excitatory receptors, certain anomalous characteristics of the kinetics of apparent binding raised the question of whether transport might contribute to this process, prompting a closer examination of it. Hyperosmolar media and low incubation temperatures (4 degrees C) both led to decreases in the apparent specific binding of [3H]glutamate to membranes from the brain of the rat in the presence of chloride. Furthermore, only 15% of the [3H]glutamate, bound at 37 degrees C, was dissociable when the membranes were then cooled to 4 degrees C. The binding of [3H]glutamate was increased in the presence of certain dipeptides such as L-phenylalanyl-L-glutamate (Phe-Glu); and the binding augmented by the presence of Phe-Glu, was also sensitive to temperature and osmolarity of the incubation buffer. Sonication of membranes in 5 mM glutamate increased the apparent binding of [3H]glutamate and abolished the stimulatory effect of Phe-Glu. These findings are consistent with the hypothesis that chloride-dependent association of [3H]glutamate with membranes from brain reflects, in part, a sequestration process, which may be driven by glutamate exchange.