Withdrawing intra-aortic balloon pump support paradoxically improves microvascular flow

Introduction

The Intra-Aortic Balloon Pump (IABP) is frequently used to mechanically support the heart. There is evidence that IABP improves microvascular flow during cardiogenic shock but its influence on the human microcirculation in patients deemed ready for discontinuing IABP support has not yet been studied. Therefore we used sidestream dark field imaging (SDF) to test our hypothesis that human microcirculation remains unaltered with or without IABP support in patients clinically ready for discontinuation of mechanical support.

Methods

We studied 15 ICU patients on IABP therapy. Measurements were performed after the clinical decision was made to remove the balloon catheter. We recorded global hemodynamic parameters and performed venous oximetry during maximal IABP support (1:1) and 10 minutes after temporarily stopping the IABP therapy. At both time points, we also recorded video clips of the sublingual microcirculation. From these we determined indices of microvascular perfusion including perfused vessel density (PVD) and microvascular flow index (MFI).

Results

Ceasing IABP support lowered mean arterial pressure (74 ± 8 to 71 ± 10 mmHg; P = 0.048) and increased diastolic pressure (43 ± 10 to 53 ± 9 mmHg; P = 0.0002). However, at the level of the microcirculation we found an increase of PVD of small vessels <20 μm (5.47 ± 1.76 to 6.63 ± 1.90; P = 0.0039). PVD for vessels >20 μm and MFI for both small and large vessels were unaltered. During the procedure global oxygenation parameters (ScvO₂/SvO₂) remained unchanged.

Conclusions

In patients deemed ready for discontinuing IABP support according to current practice, SDF imaging showed an increase of microcirculatory flow of small vessels after ceasing IABP therapy. This observation may indicate that IABP impairs microvascular perfusion in recovered patients, although this warrants confirmation.     

凝血酶肽促进缺血创面愈合与皮瓣存活的实验研究

目的探讨凝血酶受体激活肽(TP508)对促进缺血创面愈合与皮瓣存活的作用.方法SD大鼠66只,制作部分缺血创面(16只)、完全缺血创面(16只)、正常创面(18只)及皮瓣(16只)模型,每一模型又分为TP508治疗组和等渗盐水对照组.术后第3、7、10、14天,将创面或皮瓣坏死轮廓描记至醋酸纸七,输入计算机求出创面面积或坏死面积.结果术后7 d和14 d,TP508组正常创面面积仅为对照组的73.7%和45.4%.术后7 d,TP508组部分缺血创面面积为(99.8±30.7)mm2,而对照组为(128.0±43.4)mm2.术后第10天,TP508组完全缺血创面面积为(293.0±34.0)mm2,对照组为(352.4±41.2)mm2.术后第7天,TP508组皮瓣坏死面积为对照组皮瓣坏死面积的80.4%,第14天为56.8%.结论 TP508对促进大鼠缺血创面愈合和皮瓣存活均有显著作用.     

静息状态脑功能网络的研究及应用

目的:对静息状态网络的研究方法、初步的研究成果等作以介绍,并结合静息状态网络在阿尔茨海默病早期预警中的应用,介绍静息状态脑网络的应用。资料来源:应用计算机检索PubMed1980-01/2006-12与静息状态网络相关的文献,检索词“restingstate,functional connectivity”,并限定文献语言种类为“English”;同时计算机检索万方数据库1995-01/2006-12有关方面的文献,检索词为“静息,功能连接,阿尔茨海默病”,并限定语言种类为中文。资料选择:对资料进行初审,选取包括静息状态的相关文献,开始查找原文。纳入标准:①有关静息状态脑网络和功能连接的研究。②有关阿尔茨海默病的研究。排除标准:重复研究。资料提炼:共收集到53篇有关静息状态网络方面的研究,排除23篇重复性研究,30篇符合要求。资料综合:近年来,研究者发现大脑处于无任务的静息状态时,仍然存在着某种功能活动。这些现象表明大脑在静息状态时可能存在有组织的网络。这有助于对人脑高级意识和某些认知疾病的研究,因此,有关这方面的工作越来越受到人们的重视。结论:对静息状态网络的本质和规律的研究还很有限,对这个网络所支持的精确的功能还有待于进一步研究。     

Is permanent congenital facial palsy caused by birth trauma?

OBJECTIVE: To study the relation between traumatic birth and the development of permanent facial palsy in the newborn. DESIGN: Retrospective case control study of children with 'congenital' facial palsy. SETTING: Two tertiary referral centres for patients with facial palsy. SUBJECTS: 61 children with established facial palsy. MAIN OUTCOME MEASURES: Odds ratios of recognised factors for birth injury: maternal primiparity, high birth weight, and the use of obstetric forceps at delivery. RESULTS: 13.2% of those studied had forceps assisted delivery compared to 10.2% in the normal population (odds ratio 1.34; 95% confidence intervals 0.61 to 2.97) 39.6% were born to primiparae compared to a national rate of 36.7% (1.13; 0.65 to 1.96) and only 18.9% weighed more than 3500 g at birth (0.37; 0.19 to 0.74). CONCLUSIONS: There is no association between the development of permanent 'congenital' facial palsy and recognised risk factors for birth injury. These data suggest an intrauterine rather than a traumatic aetiology.     

Abdominal tuberculosis: CT evaluation

The computed tomography (CT) scans of 27 patients with abdominal tuberculosis were reviewed retrospectively to determine the range of abdominal involvement. Most patients had been at increased risk because of intravenous drug abuse, alcoholism, acquired immunodeficiency syndrome (AIDS), cirrhosis, or steroid therapy. The etiologic agent was Mycobacterium tuberculosis in 23 patients and M. avium-intracellulare in four patients with AIDS. In five patients, tuberculosis was limited to the abdomen. CT findings included adenopathy, splenomegaly, hepatomegaly, ascites, bowel involvement, pleural effusion, intrasplenic masses, and intrahepatic masses. Characteristic features were a tendency for adenopathy to prominently involve peripancreatic and mesenteric compartments, low-density centers within enlarged nodes, complex nature of the ascites, and adenopathy adjacent to sites of gastrointestinal tract involvement. Recognition of these manifestations and maintenance of an index of suspicion, especially in patients at risk, should help optimize the correct diagnosis and management of intraabdominal tuberculosis.     

水溶性药物的疏水性修饰及其重组型脂质体的研究

脂质体载水溶性药物出现的共同问题是药物的包封量低、稳定性差。本文以甲硝唑(Ⅰ)为水溶性药物模型,进行疏水性结构修饰,得其肉豆蔻酸酯(Ⅱ)前体药物,分别进行Ⅰ和Ⅱ的脂质体研究,结果表明Ⅱ在脂质体中的包封率较Ⅰ提高10倍以上,渗漏速率降至十分之一,制成含Ⅱ的脂质干膜,经超声分散,可得合乎要求的重组型脂质体,为解决脂质体载药的稳定性问题提供有效途径。体外抗阿米巴原虫试验,镜检观察到载药脂质体进入阿米巴原虫的细胞内,且100%抑制原虫所需剂量Ⅱ脂质体是Ⅰ游离药的二分之一。因此药物疏水化修饰是解决脂质体载水溶性药物稳定性问题的理想途径。