Changes in Intensity of Serotonin Syndrome Caused by Adverse Interaction between Monoamine Oxidase Inhibitors and Serotonin Reuptake Blockers

Drug interaction between inhibitors of monoamine oxidase (MAOIs) and selective serotonin (5-hydroxytryptamine, 5-HT) reuptake (SSRIs) induces serotonin syndrome, which is usually mild but occasionally severe in intensity. However, little is known about neural mechanisms responsible for the syndrome induction and intensification. In this study, we hypothesized that the syndrome induction and intensity utilize two different but inter-related mechanisms. Serotonin syndrome is elicited by excessive 5-HT in the brain (presynaptic mechanism), whereas syndrome intensity is attributed to neural circuits involving 5-HT_2A and NMDA receptors (postsynaptic mechanism). To test this hypothesis, basal 5-HT efflux and postsynaptic circuits were pharmacologically altered in rats by once daily pretreatment of the MAOI clorgyline for 3, 6, or 13 days. Syndrome intensity was estimated by measuring 5-HT efflux, neuromuscular activity, and body-core temperature in response to challenge injection of clorgyline combined with the SSRI paroxetine. Results showed that the onset of serotonin syndrome is caused by 5-HT efflux exceeding 10-fold above baseline, confirming the presynaptic hypothesis. The neuromuscular and body-core temperature abnormalities, which were otherwise mild in drug-naive rats, were significantly intensified to a severe level in rats pretreated with daily clorgyline for 3 and 6 days but not in rats pretreated for 13 days. The intensified effect was blocked by M100907 and MK-801, suggesting that variation in syndrome intensity was mediated through a 5-HT_2A and NMDA receptor-engaged circuit. Therefore, we concluded that pretreatments of MAOI pharmacologically alter the activity of postsynaptic circuits, which is responsible for changes in syndrome intensity.     

Heart Rate Variability in Peritoneal Dialysis Patients: What Is the Role of Residual Renal Function?

Background: The relationship between heart rate variability (HRV) and residual renal function (RRF) has not been elucidated previously. Methods: In this cross-sectional study, HRV was evaluated in 71 peritoneal dialysis patients. Patients were divided into RRF decline group, RRF stable group and anuric group. Results: RRF was negatively correlated with SDNN (r = -0.284, p = 0.017), TP (r = -0.247, p = 0.039), and HF (r = -0.238, p = 0.047). Significant sympathetic nerve activation was found in the RRF decline group (significantly lower SDNN, SDSD, RMSSD, pNN50, LF, HF, TP and higher LF/HF ratio) as compared to the RRF stable and anuric groups. Besides, significantly parasympathetic activation was found in the anuric group (the lowest LF/HF ratio as compared to the other groups (both p < 0.05). Multivariate stepwise regression analysis showed that the status of RRF was an independent factor associated with HRV parameters. Conclusion: This study showed autonomic nervous function in peritoneal dialysis patients was associated with a different status of RRF.     

游离髂骨联合腹股沟皮瓣带蒂移植修复手指背侧骨皮缺损

目的观察游离髂骨联合腹股沟皮瓣移植修复手指背侧骨皮缺损的临床效果。方法自2008年2月至2011年12月我中心收治的7例手指背侧骨皮缺损的患者,手术方案为:3例污染较轻者经急诊清创后Ⅰ期给予修复,4例感染者Ⅰ期彻底清除病灶,控制感染后,Ⅱ期行游离髂骨植骨微型接骨板内固定手指于功能位,腹股沟皮瓣修复软组织缺损。结果术后3⁴周断蒂,皮瓣全部成活;临床植骨愈合时间为8周3例,9周4例,平均8.5周;术后3个月复查全部病例均达到骨性愈合。随访104周断蒂,皮瓣全部成活;临床植骨愈合时间为8周3例,9周4例,平均8.5周;术后3个月复查全部病例均达到骨性愈合。随访10³6个月,皮瓣质地良好,外观满意,髂骨塑形良好,未出现骨髓炎、骨不愈合等情况。结论游离髂骨联合腹股沟皮瓣移植修复手指骨皮缺损是一种理想方法,简单易行,值得临床推广。     

第一跖趾关节镜在矫治拇外翻中的应用进展

随着技术和器械的不断发展,小关节关节镜技术日趋成熟.在足踝领域,第一跖趾关节镜治疗拇外翻的方法被越来越多的医师应用于临床,并取得了一定成效.它不仅可以用于诊断,也可以用于治疗.由于是新技术,它也不可避免的存在一些问题和局限性.本文将对第一跖趾关节镜在矫治拇外翻中的应用进展做一综述.     

六分钟步行距离试验在鉴别肺高血压血流动力学类型中的价值

目的 探讨6 min步行距离试验在鉴别肺高血压血流动力学类型中的意义.方法 收集164例心功能Ⅱ～Ⅲ级初诊肺高血压患者的临床资料进行回顾性分析.根据肺高压血流动力学指标及右心功能状况分为A组(毛细血管前肺动脉高压、右心功能正常,62例)、B组(毛细血管后肺动脉高压、右心功能正常,58例)、C组(毛细血管前肺动脉高压合并右心功能不全,44例),主要分析指标为6 min步行距离及运动前后动脉血氧饱和度.结果 A组、B组和C组6 min步行距离分别为(397±112)、( 299±63)和(294±111)m,A组明显高于B组和C组,组间差异有统计学意义(P＜0.01)；B组与C组间比较差异无统计学意义(P＞0.05).结论 肺高血压合并心功能不全6 min步行距离明显减少；但单独6 min步行距离检查不能区分血流动力学类型.