Neuromuscular transmission as a function of motor unit size in patients with prior poliomyelitis.

We studied neuromuscular transmission in 16 patients with prior poliomyelitis by measuring single fiber electromyographic (SFEMG) jitter. This was compared with 3 indirect methods of assessing reinnervation: SFEMG fiber density, macro EMG, and the presence of fiber type grouping on muscle biopsy. In patients with acute poliomyelitis before the age of 10, there was a positive correlation between the extent of neuromuscular transmission impairment, demonstrated by increased SFEMG jitter, and the enlargement of the motor unit, as indicated by increased fiber density, increased macro EMG signals, and fiber type grouping on muscle biopsy. However, there was no correlation between any of these parameters and the presence or absence of new symptoms of weakness. These findings suggest that impaired neuromuscular transmission is most common in patients with prior poliomyelitis whose motor units have been maximally enlarged by axonal sprouting, but is independent of the presence or absence of new symptoms of weakness.     

Evolution and path models in human behavioral genetics

The evolutionary implications of the path-analysis model most often used in human behavior genetics are examined. With directional selection, a model of pure vertical environmental transmission does not respond in a fully adaptive fashion. Unless the coefficients of transmission are exactly 0.50, the population mean will not equilibrate at the selective optimum over time. If there is both genetic and vertical environmental transmission, then the population mean can equilibrate at the selective optimum. In the presence of genetic transmission, vertical environmental transmission increases population fitness and has a strong effect on the rapid movement of the mean toward the selective optimum. This raises the intriguing paradox of why empirical evidence suggests that vertical environmental transmission is usually small when it possesses such important fitness properties.This work was supported in part by Grant DA05131 from the National Institute on Drug Abuse.     

预防艾滋病毒性传播的杀微生物剂的研究现状

杀微生物剂的应用是预防艾滋病毒性传播的重要途径.本文阐明了艾滋病毒的性传播机制和杀微生物剂的作用机理,进一步综述了杀微生物剂的类型及其发展前景.     

海岛纤恙螨经卵传递恙虫病立克次体的研究

1985年8月～1986年11月,作者以我国发现的恙螨新种海岛纤恙螨子代幼虫656只,分为21组,叮咬健康小鼠,从子1代到子4代幼虫叮咬过的小鼠中,连续分离出7株恙虫病立克次体,证明海岛纤恙螨能够经卵传递恙虫病立克次体至少4代.同时在该螨的卵、幼虫、若虫、成虫组织细胞内发现有恙虫病立克次体寄生,并发现有分裂增殖形态的立克次体,证明海岛纤恙螨各变态期内均保有恙虫病立克次体,这些立克次体能在恙螨体内大量增殖,连续传代.此项研究结果,对于确认海岛纤恙螨为浙江沿海地区恙虫病的传染媒介和宿主,提供了重要的科学依据.     

北京地区361名孕妇乙型肝炎流行病学研究

从1985年4月到1986年4月对361名孕妇进行的乙型肝炎流行病学横断面研究以及196名产妇一年随访研究的结果表明,361例孕妇的HBsAg阳性率为2.5%,抗-HBs阳性率为23.8%,抗-HBc阳性率为22.1%,HBV总感染率为31.3%;抗-HBs阳性、抗-HBs和抗-HBc共存阳性者占总阳性者的76.1%,说明人群感染HBV后大多产生了免疫力.1986年4月复查了196例产妇,133名在1985年HBV标记阴性者中有6人获得了HBV标记,HBV新感染率为4.5%;1例为急性乙型肝炎病人,5例为亚临床感染.HBV新感染者的感染途径不明,但医源性传播不能排除.1986年检查的148对夫妇中,男性HBsAg阳性率是女性的3.1倍(6.1%对2.0%),男性单独抗-HBc阳性率是女性的2.3倍(6.1%对2.7%),抗-HBs、抗-HBs和抗-HBc共存以及HBV感染率男女性间都无显著差异.     

Effect of exogenous progesterone administration on the morphology of normally developing endometrium in the pre-implantation period

The effects on endometrial morphology of a single, intramuscular dose of 100 mg of progesterone administered in the early luteal phase, between days LH + 1 and LH + 6, were studied in a group (n = 8) of normal, fertile subjects by morphometric techniques and transmission electron microscopy. While the dose of progesterone administered consistently resulted in an increase of salivary progesterone concentration to above the upper limit of the reference range, no significant effect on endometrial development was observed; in particular, endometrial development was not advanced.     

Measurement of acceleration: a new method of monitoring neuromuscular function

A new method for monitoring neuromuscular function based on measurement of acceleration is presented. The rationale behind the method is Newton's second law, stating that the acceleration is directly proportional to the force. For measurement of acceleration, a piezo-electric ceramic wafer was used. When this piezo electrode was fixed to the thumb, an electrical signal proportional to the acceleration was produced whenever the thumb moved in response to nerve stimulation. The electrical signal was registered and analysed in a Myograph 2000 neuromuscular transmission monitor. In 35 patients anaesthetized with halothane, train-of-four ratios measured with the accelerometer (ACT-TOF) were compared with simultaneous mechanical train-of-four ratios (FDT-TOF). Control ACT-TOF ratios were significantly higher than control FDT-TOF ratios: 116 +/- 12 and 98 +/- 4 (mean +/- s.d.), respectively. In five patients not given any relaxant during the anaesthetic procedure (20-60 min), both responses were remarkably constant. In 30 patients given vecuronium, a close linear relationship was found during recovery between ACT-TOF and FDT-TOF ratios. It is concluded that the method fulfils the basic requirements for a simple and reliable clinical monitoring tool.     

Eight-channel transmit/receive body MRI coil at 3T.

Multichannel transmit magnetic resonance imaging (MR) systems have the potential to compensate for signal-intensity variations occurring at higher field strengths due to wave propagation effects in tissue. Methods such as RF shimming and local excitation in combination with parallel transmission can be applied to compensate for these effects. Moreover, parallel transmission can be applied to ease the excitation of arbitrarily shaped magnetization patterns. The implementation of these methods adds new requirements in terms of MRI hardware. This article describes the design of a decoupled eight-element transmit/receive body coil for 3T. The setup of the coil is explained, starting with standard single-channel resonators. Special focus is placed on the decoupling of the elements to obtain independent RF resonators. After a brief discussion of the underlying theory, the properties and limitations of the coil are outlined. Finally, the functionality and capabilities of the coil are demonstrated using RF measurements as well as MRI sequences.     

新的质粒介导的碳青霉烯酶IMI-3传播机制研究

目的明确新的质粒介导的碳青霉烯酶IMI-3传播机制.方法采用E试验测定抗菌药物MIC,接合试验、酶切克隆筛选及鸟枪法测序对编码基因IMI-3传播机制进行研究.结果发现阳性克隆菌E.coli pT103有5个开放读码框（ORF）.在编码基因IMI-3的两侧各有一相同的插入序列,氨基酸序列与IS903有71%的同源性.鸟枪法测序显示IMI-3与染色体介导的IMI-有99%的同源性.结论IMI-3编码基因是由位于染色体上的IMI-1经点突变通过转座酶Tn903转移至可接合性质粒上.     

流行性出血热流产婴儿与胎盘的病理变化及巨噬细胞内抗原定位

妊娠6~ 个月孕妇感染流行性出血热(EHF),临床有典型的EHF的发病过程。第23病日血清学检测孕妇外周血EHF-IgG(卅)、IgM(-),第24病日流产一女婴,抽取脐带血检测EHF-IgG(卅),流产女婴心血检测EHF-IgG(卅),IgM(-)。病理:肾小球上皮细胞肿胀,上皮细胞足突融合、坏死,毛细血管基底膜皱缩,肾小管上皮细胞线粒体肥大,间质内大单核细胞浸润。肺间质细胞增生、水肿、毛细血管基底膜不规则增厚,肺泡壁Ⅱ型细胞增多。肝细胞肿胀,胞浆内查见包涵体样物质,有多核肝巨细胞,地依红染色阴性。胎盘母体面、脐带、肺、肝间质内大单核细胞、中性粒细胞浸润。EHF-MCAb荧光直接法染色、PAP、ABC等免疫组化染色,在巨噬细胞浆内均为阳性反应,从而证实母体感染EHF可以经胎盘感染给胎儿,其传播方式可能是通过巨噬细胞系统。