Influence of the Compliance of the Pump Housing and Cannulas of a Paracorporeal Pneumatic Ventricular Assist Device on Transient Pressure Characteristics

Abstract: The dependence of transient pressure characteristics of a ventricular assist device (VAD) on the compliance of its housing and cannulas was investigated in a mock circulation. The peak rate of change of pressure ( dP/dt _max) values was greater in the cannulas than other compartments and was associated with valve closure-induced pressure oscillations. When cannula compliance was increased from 0.0057 to 0.0129 cm³/mm Hg, these values decreased by ˜20%, and outflow cannula pressure oscillation frequency decreased from 17.5 Hz by 35%. This trend was also apparent in the inflow. A VAD housing compliance increase from 0.0162 to 0.0483 cm³/mm Hg caused a dP/dt _max decrease of 30% in both the blood chamber and the outflow cannula. The effect of this change on the inflow was weaker implying that housing absorbs the energy associated with outflow deceleration more effectively than the inflow. These findings suggest that increasing VAD housing and cannulas compliance can improve hydrodynamic performance.     

Evolution of the sperm aster after microinjection of isolated human sperm centrosomes into meiotically mature human oocytes

This study examined the feasibility of isolating and transferringthe centrosome-containing region of spermatozoa to mature humanoocytes. The findings demonstrate that individual sperm centrosomescan be transferred and are capable of nucleating maternal tubulinto form a well-developed sperm aster in the recipient oocyte.The results are discussed with respect to centrosome functionin early human development and applications in clinical in-vitrofertilization in the treatment of certain forms of male factorinfertility.     

溴氰菊酯对白纹伊蚊（Aedesalbopictus）C6／36细胞株的细胞遗传学效应

本研究选择１０μｇ／ｍｌ、２０μｇ／ｍｌ、４０μｇ／ｍｌ浓度的溴氰菊酯处理白纹伊蚊Ｃ６／３６细胞，以ＭＭＣ作为阳性对照物，观察溴氰菊酯处理２４ｈ后对Ｃ６／３６细胞染色体畸变率和姐妹染色单体互换（ＳＣＥ）频率的影响。结果显示，三个浓度的溴氰菊酯对Ｃ６／３６细胞染色体畸变率均没有显著影响（Ｐ＜０．０５）；溴氰菊酯浓度在４０μｇ／ｍｌ时可诱导Ｃ６／３６细胞ＳＣＥ频率轻度增高（Ｐ＞０．０５），而溴氰菊酯浓度在１０μｇ／ｍｌ、２０μｇ／ｍｌ时，对Ｃ６／３６细胞ＳＣＥ频率没有诱导作用。表明溴氰菊酯对Ｃ６／３６细胞的遗传学效应较弱     

浅低温心脏不停搏心内手术对心肌保护效果的比较

目的:探讨浅低温体外循环(CPB)心脏搏动中心内直视手术对心肌保护的效果.方法:40例患者随机分为观察组(浅低温心不停搏组)和对照组(中低温心停搏组).分别在术前、转机、停机及术后6 h、12 h、24 h、48 h、72 h,取冠状静脉窦或中心静脉血样,测定血气分析及血清中肌酸磷酸激酶(CK)及其同功酶(CK-MB)、天门冬氨酸氨基转换酶(AST)、乳酸脱氢酶(LDH)、丙二醛(MDA)、超氧化物歧化酶(SOD)的含量.并取心房间隔肌观察心肌含水量及心肌超微结构的改变.临床观察CPB时间、脱机、呼吸支持、多巴胺应用、严重心律失常和血红蛋白尿等指标.结果:冠脉循环血气、电解质、酸碱水平与体循环的组内组间对比基本一致.CK、CK-MB、AST、LDH两组在CPB和术后均有增加,且以对照组升高显著,与观察组相同时点相比,差异均有显著性(P＜0.01).对照组术后MDA明显升高,SOD明显降低(P＜0.01),而观察组变化不大.心肌含水量和超微结构观察,对照组变化显著,而观察组轻微改变.临床指标观察,观察组优于对照组.结论:浅低温体外循环心脏不停搏心内直视手术对心肌损伤很轻,有很好的心肌保护效果.     

慢性低氧大鼠肺动脉内皮素mRNA的表达及定位

目的：探讨慢性低氧大鼠肺动脉内皮素－1基因表达及分布。方法：采用生物素标记cRNA探针，对Wistar大鼠肺动脉进行原位杂交。结果：低氧1周组及低氧2周组大鼠大部分肺动脉内皮细胞ET－1mRNA表达呈阳性信号，而对照组大鼠仅极少数阳性信号（P＜0．01）；低氧1周组大鼠部分显示强阳性信号。低氧1周组及低氧2周组大鼠部分肺动脉平滑肌细胞呈现ET-1mRNA表达阳性信号，而对照组大鼠则无阳性信号表达（P＜0．01及0．05）。结论：慢性低氧对大鼠肺动脉ET－1分泌的影响是在基因转录水平进行，且主要细胞定位在肺动脉内皮细胞，此外还包括肺动脉平滑肌细胞。     

非鼻咽部T细胞淋巴瘤与EB病毒的相关性

目的：探讨EB病毒（EBV）感染与非鼻咽部T细胞淋巴瘤的关系。方法：用单克隆抗体UCHL-1、L26及EB病毒编码的潜在膜蛋白-1（LMP-1），免疫组化染色确定肿瘤的免疫表型及EB病毒转化蛋白的表达。采用原位杂交方法检测EBV编码的EBERs。结果：21例非鼻咽部T细胞淋巴瘤EBERs5例阳性的（23．8％），其中给内淋巴瘤3例，肺和胃肠淋巴瘤各1例。阳性细胞约占肿瘤细胞的10％～70％。5例EBERs阳性病例中仅1例表达LMP-1，为结内淋巴瘤。结论：非鼻咽部T细胞淋巴瘤可能与EBV的感染有关，LMP-1的阳性率较EBERs低。     

异位子宫内膜和在位子宫内膜分泌泌乳素的研究

作者将29例子宫内膜异位症（简称异位症）患者的异位和在位内膜进行离体组织孵育，应用放射免疫方法检测孵育液中泌乳素（PRL）含量；同时应用ABC免疫酶标记法确定异位和在位内膜分泌PRL的部位，结果异位和在位内膜离体组织经0～24h孵育，孵育液中PRL含量均显著增加（P＜0．05）；继续孵育至48h，PRL含量不再增加。但异位内膜分泌PRL的活性低于自身在位内膜。免疫组化PRL检测，异位和在位内膜分别有4和6例呈PRL阳性反应。组织学对照现察，内膜成熟上皮细胞数及前蜕膜细胞数越多者，其相应孵育液中PRL含量越高，免疫组化PRL阳性反应也越强。提示异位内膜PRL分泌特点与其自身在位内膜不完全相同，可能与病理环境有关。     

Gestion des risques et choix de maintenance à l'hôpitalRisks management and maintenance choices at the hospital

Regulations evolve and risks management becomes one of the biomedical engineers' preoccupations. Thus, risks are various, and consequently it is difficult to identify, to manage and to bring them under control. Furthermore, regulations exist for sectors like healthcare technology monitoring, but it is not the same thing for instance for the risks linked to the maintenance. Thus regulation in the sector of maintenance evolves and the decree of the 1^st July law of health safety is going to modify the biomedical environment. The goal of this work is to study the tools and the methods of risks management that have been used for several years in the industrial field and to use them for some biomedical equipment like monitors or IV pumps. These methods adapted to these equipment will allow us to determine some appropriate rules of maintenance.     

Is pregnancy the best treatment for hyperprolactinaemia?

This paper reports the changes in prolactin levels after 12 spontaneous and 52 induced pregnancies in 54 women with unambiguous hyperprolactinaemia (median plasma prolactin levels 67.5 ng/ml, range 40-400). Twenty-three of the patients showed radiological evidence of prolactinoma. The pregnancies were induced in 37 patients by bromocriptine, in nine by metergoline, in two by lisuride and in four by other treatments. Of the 64 pregnancies, 16 ended in spontaneous abortion, while 48 went to term. Follow-up was continued for at least 6 months after delivery or until the end of lactation. In a control group of 32 hyperprolactinaemic women (median prolactin 70 ng/ml, range 40-400) not wishing to become pregnant, prolactin changes were similarly registered over a mean period of 15 months without any treatment (range 6-38 months). After pregnancy, a significant downward trend of plasma prolactin was observed in the puerperal women with a 'normalization' rate of 17%. No changes were observed in the 32 controls who did not become pregnant.