THE CONTROL OF HUMAN MOTOR UNITS

1. The motor unit, consisting of a single motor neuron and the skeletal muscle fibres that it innervates, is the final output pathway of the motor system. 2. Much is now known about the way that human motor neurons are recruited and controlled during voluntary and reflex movements. This review briefly summarizes some of the recent experimental data that has contributed to our present understanding. The review is largely limited to data obtained in human experiments. While much of what we know about the organization of the nervous system has come from studies of the anatomy and physiology of experimental animals, there are some questions that cannot be addressed in reduced animal preparations. The development of new techniques has made it possible to investigate the human nervous system at a level of detail that has not hitherto been possible.     

Oral tolerance in EAE: reversal of tolerance by T helper cell cytokines

Oral administration of myelin basic protein (MBP) inhibits clinical and histopathological manifestations of experimental autoimmune encephalomyelitis (EAE), but only partially reduces serum anti-MBP antibody titers. We report here that orally administered MBP alters the isotypic distribution of anti-MBP antibody-forming cells (AFC) among various lymphoid tissues, with the most profound differences seen in mucosal tissues. We observed an isotype-selective reduction in anti-MBP IgA but not IgM AFC frequencies in Peyer's patches. The anti-MBP IgA AFC frequencies could be reconstituted by addition of interleukin 4 (IL-4) and interleukin 5 (IL-5). The cytokines did not appear to generate de novo responses since no increases in anti-MBP IgA AFC frequencies were observed in control cultures. These results indicate that decreased antibody production, as a result of oral antigen administration, can be reversed by exposure to the appropriate cytokines.     

Local health services: some lessons from their evolution in Bolivia

Summary For a decade, numerous projects in Bolivia have tried to put in practice the concept of local health systems. But, so far, no significant changes have been made and local health services still are the 'poor relation' of the system. The main components of the project—expansion of health facilities, training of health personnel and institutional decentralization—were not designed to respond to the complexity of the problems encountered. Decentralization was implemented at the level of health districts but not accompanied by redefinition of functions at the central level, and challenged by civil servants' attempts to save their jobs. While training activities did introduce new methods and subjects, they were too often reduced to short workshops or seminars. Health facilities were built without regard for their significance beyond health care. A strategic approach is needed to adapt the planning process to the degree of liberty allowed by society.     

局麻胸腔镜清创术治疗脓胸实用性研究

目的探讨脓胸患者经局麻胸腔镜清创术治疗的实用价值。方法在局麻下用硬质电视胸腔镜行脓胸清创术，介绍操作方法及清创步骤，观察患者的耐受性及疗效。结果总有效率为90．6％，早、中、晚期治疗有效率分别是100．0％、90．9％、50．0％。术中监测患者对操作的反应及血氧饱和度、呼吸、脉搏、心电图改变均无统计学意义。结论局麻胸腔镜清创术在患者清醒状态下操作，除抽净黏稠脓液外尚可取出团块状脓苔及坏死组织，打穿包裹性脓腔，充分冲洗，可迅速控制感染。方法简单，避免全麻气管插管带来的并发症，术后恢复快，适应证广，患者易耐受，是治疗脓胸的实用方法。     

肛门病手术应用低浓度小剂量利多卡因局麻的效果

目的观察低浓度小剂量利多卡因在肛门病手术中的应用效果。方法选择接受肛门病手术者100例,手术时用0．25％盐酸利多卡因5-20ml,根据病情和手术需要作局部浸润麻醉。结果通过100例的肛门手术观察,结果显示麻醉满意顺利83例,麻醉良好17例,无1例麻醉无效失败。总有效率100％。此法麻醉效果确切,未发现严重不良反应。结论此法具有易于掌握,效果好而安全的优越性,适于临床应用和推广。     

Gastric contents and pH after oral premedication

Forty women, aged 26-40 years, were investigated with regard to gastric contents and pH before general anaesthesia. The patients were divided into two groups (20 in each). Group 100 received 0.3 mg kg-1 diazepam orally with 100 ml of water 2 h before surgery. Group 50 received 0.3 mg kg-1 diazepam with 50 ml of water 2 h before surgery. The amount of gastric content was significantly greater in Group 100 than in Group 50 (P less than 0.05). There was no statistical difference in pH values between the groups. The number of patients with both gastric pH less than 2.5 and gastric volume greater than 25 ml was significantly higher in Group 100 compared to Group 50 (P less than 0.05). We cannot recommend the use of oral premedication using these amounts of water, considering the increased risk of aspiration of gastric contents.     

局部浸润麻醉在隆乳术中的应用

目的 探讨局部浸润麻醉方法在隆乳术中的应用效果。方法 将2％利多卡因20ml加0．5％布匹卡因5ml配制成120ml局部麻醉液，采用局部浸润麻醉方法为568例受术者行隆乳手术，根据胸部神经、肌肉的解剖特点，行合理的分布药量和准确有效的注射。结果 568例隆乳术者，局部浸润麻醉方法均有效，且麻醉效果良好。无一例受术者因分离腔穴时产生疼痛而影响手术操作或停止手术。结论 局部麻醉效果理想可靠，方法简单易行，适用于任何术式的隆乳术。而在分离腔穴时产生的疼痛主要是因注射层次不当和药量分布不均所致。与麻醉方法无关；其麻醉效果与假体置入层次或乳腺胸大肌是否发达无因果关系。