Modulation of triceps surae H-reflexes as a function of the reflex activation history during standing and stepping

The facilitatory effectiveness of spindle afferent feedback is controlled by modulation of segmental reflex excitability such that the level of muscle activation is appropriate for the task. Phase-dependent modes of reflex modulation have been well-characterized. We hypothesized that segmental reflex excitability of the triceps surae was also modulated in a manner associated with the activation history of the spindle afferents and the segmental reflex pathway during isometric contractions, standing and stepping. In the first experiment. pairs of soleus (S) H-reflexes were evoked 80 ms apart with equal strength stimuli at rest and while subjects isometrically contracted their S against loads of 10%. 20%. and 50% of their maximum voluntary efforts. The percent depression of the second H-reflex relative to the first was used as a measure of the effect of reflex activation history. At rest, the second H-reflexes were depressed an average of 73% relative to the first. The degree of depression was progressively reduced as the plantarflexion torque increased. In the second experiment, paired H-reflexes were obtained from the S and medial (MG) and lateral gastrocnemii (LG) muscles while subjects were standing and during the stance phase of step initiation. The degree of depression of the second H-reflex during standing ( > 78%) was similar in magnitude to that produced at rest in Experiment I. At the end of the stance phase of stepping. depression of the second H-reflex of all three muscles was reduced to less than 25%. We conclude that the segmental reflex excitability is modulated as a function of the reflex activation history during these tasks.     

穿透性角膜移植术治疗坏死性基质角膜炎23例

目的:探讨穿透性角膜移植术(penetratingkeratoplasty,PKP)治疗坏死性基质角膜炎(necrotizingstromalkeratitis)的手术适应证及其临床效果。方法:按照Holland等的HSK新分类法,选择确诊坏死性基质角膜炎患者,予以局部及全身药物治疗。对病情不能控制,药物治疗无效的患者22例(23眼),其中角膜溶解穿孔3眼,用新鲜角膜组织行穿透性角膜移植术,并随访观察术后疗效。结果:随访3mo～3a,22例(23眼)中,术后视力提高者18眼,其中矫正视力达到0.1～0.5者12眼,0.05～0.1者6眼;无改善者5眼。角膜植片透明17眼,半透明2眼,植片混浊4眼,植片透明率为74%。术后3眼植片发生排斥反应,3眼原发病灶复发。2眼术后因排斥反应及原发病灶反复发作,植片完全混浊,行2次角膜移植术。结论:对坏死性基质角膜炎患者,药物保守治疗无效、角膜坏死穿孔或行将穿孔,及时用新鲜角膜组织行穿透性角膜移植术治疗,不仅能控制炎症,缩短病程,而且能保存眼球,恢复部分视力,因此具有重要临床应用价值。     

做公立医院产权制度改革的促进派

经过数年来政府各有关部委的协商努力，医疗卫生各界人士付出了相当的摩擦成本和交易成本，特别是在抗击非典战役的洗礼后，卫生部新领导的新思路发挥指导作用，公立医院的产权制度改革方向终于明确了。卫生部医政司吴明江司长在全国政协举行的一次研讨会上，就医院产权制度改革发表重要谈话，记者在《健康报》     

长期雾化吸入硝酸甘油对高肺血流大鼠肺动脉压力及肺血管结构重建的影响

目的探讨长期雾化吸入硝酸甘油对高肺血流大鼠肺动脉压力、肺血管结构的作用及其机制。方法24只健康雄性Wistar大鼠随机分为对照组、分流组和吸入组。对分流组和吸入组大鼠开腹行腹主动脉-下腔静脉分流术,12周后两组大鼠分别雾化吸入生理盐水和硝酸甘油3周。以右心导管法测定肺动脉压,颈动脉插管测定体循环压,检测右心室肥厚,观测肺血管显微及超微结构变化,用免疫组织化学法检测大鼠肺动脉人类尾加压素Ⅱ(hUⅡ)的表达。结果分流组大鼠肺动脉平均压(PAMP)和右心室/左心室 室间隔重量比值(RV/LV S)明显高于对照组(P<0.01),且分流组大鼠肺小血管肌化程度明显增强(P<0.01),中、小型肺肌型动脉相对厚度(RMT)增加,肺动脉内皮细胞和平滑肌细胞hUⅡ表达明显增强。吸入组大鼠mSBP未受影响,PAMP明显低于分流组(P<0.01),RV/(LV S)高于对照组(P<0.01),但与分流组比较差异无显著性(P>0.01),吸入组大鼠肺小血管肌化程度明显改善,小型肺肌型动脉RMT及小型肺动脉内皮细胞和平滑肌细胞hUⅡ减少。结论长期雾化吸入硝酸甘油可缓解高肺血流量所致肺动脉高压和肺血管结构的重建,其对肺动脉内皮细胞和平滑肌细胞hUⅡ表达的抑制作用,可能参与高肺血流量所致肺血管结构重建和肺动脉高压的调节。     

The role of laparoscopy in the management of suspected recurrent pediatric hernias

BACKGROUND: This report examines recurrent pediatric groin hernias and the role of diagnostic laparoscopy in the management of these recurrences. METHODS: A chart review of 19 children presenting with recurrent hernias was performed, analyzing the type of primary hernia, nature of recurrence, preexisting medical conditions, surgical complications at primary repair, and time to recurrence. Diagnostic laparoscopy (DL) was used during the remedial repair of the last nine patients. RESULTS: Seventeen indirect hernias were repaired during the primary repair, and 1 femoral hernia was identified. In one child, no inguinal hernia was identified at the initial operation. Overall, 11 recurrences were found to consist of indirect sacs, and 4 were found to have attenuation of the inguinal floor. Four additional recurrences were found to be femoral hernias. In only 1 patient was a wound factor (infection) thought to play a role in the recurrence. Diagnostic laparoscopy in 9 patients found 4 (44%) to have unsuspected intraoperative findings. Four femoral hernias were identified (3 with unsuspected contralateral femoral hernias). Additionally, 1 unsuspected recurrence of an indirect sac was identified. CONCLUSIONS: Laparoscopy accurately identifies the nature of the defect in children with recurrent groin hernias, detecting unsuspected contralateral indirect, direct, or femoral hernias in 44% of those undergoing laparoscopy.     

剖宫产率上升的因素分析

目的分析剖宫产率升高的原因,寻求解决问题的办法,严格掌握剖宫产的手术指征,使诊治更为科学,确保母婴健康。方法对1996年1月1日￣2005年10月31日在我院进行剖宫产手术分娩的1570例病例进行回顾性分析,总结分析剖宫产率上升的原因及因素变迁,并提出相应的对策。结果剖宫产率呈逐年上升趋势,尤其近5￣6年来,上升明显,究其原因,胎儿窘迫、头盆不称、孕妇精神因素及部分社会因素为主要因素。结论加强围产期宣教,认真做好孕产期监护,医患之间加强沟通,减少医患纠纷,严格掌握剖宫产指征,以最大限度地降低剖宫产率和母婴死亡率。     

The expression of TRPA1 mRNA in the rat brain

Objective： To investigate the distribution of TRPA1 （one kind of the TRP-like ion channel family） channel in the hippocampus and cerebral cortex of rat. Methods： RT-PCR was used to amplify the fragment of TRPA1 in the DRG （dorsal root ganglion）, hippocampus and cerebral cortex of adult SD rat. In situ hybridization staining was used to show the distribution of TRPA1 mRNA in the hippocampus and cerebral cortex of adult rat brain. Results： Both RT-PCR and in situ hybridization staining showed that TRPA1 mRNA was expressed in hippocampus and cerebral cortex of the adult rat brain. Conclusion： Our results suggest that there is expression of TRPA1 mRNA both in the hippocampus and cerebral cortex of the adult rat brain.     

北京地区7~18岁青少年血脂现状调查

目的通过最新一轮的北京地区儿童青少年血脂调查，建立新的正常参考值。 方法于2004-09，随机选取7~18岁北京市中小学生共971人，均来自北京市区及郊区各县。根据年龄(每3岁为一年龄段)及性别分为8组(7~9岁男、女组；~12岁男、女组；~15岁男、女组；~18岁男、女组)，应用日立7060型全自动生化分析仪检测其空腹血浆总胆固醇(TC)、甘油三酯(TG)、高密度脂蛋白胆固醇(HDL C)及低密度脂蛋白胆固醇(LDL C)浓度，分别取TC、LDL C第75百分位及第90百分位点作为临界高限及高胆固醇血症浓度，取TG第90百分位点作为高甘油三酯血症浓度，取HDL C第5百分位点作为低高密度脂蛋白浓度，建立北京地区儿童血脂参考值。 结果971名儿童的血浆脂蛋白含量值呈正偏态分布，7~9岁男女性别组间血脂4项浓度；~12岁性别组间TG含量女高于男，余3项无统计学差异；~15岁性别组间TC及LDL C含量女高于男，余2项无统计学差异；~18岁性别组间TC及HDL C女高于男，余2项无统计学差异。 结论通过对971名北京市中小学生的血脂调查，建立了北京地区不同年龄性别儿童青少年的血脂正常值，确立了临界高胆固醇和高胆固醇血症浓度、高甘油三酯血症浓度和低高密度脂蛋白浓度。     

常导型MR磁体温度控制部分原理及故障处理

本文主要介绍常导型MR磁体温度控制部分的组成、原理及常见故障的分析和维修。     

支气管肺组织炎性损伤和抗炎性损伤因素的平衡机制

目的:介绍支气管肺组织炎性损伤和抗炎性损伤因素的平衡机制.方法:查阅近年来国内外文献资料.结果与结论:支气管肺组织炎性损伤因素主要涉及氧化物系列、中性粒细胞弹性蛋白酶及基质金属蛋白酶等,而抗炎性损伤因素包括抗氧化物系列、中性粒细胞弹性蛋白酶抑制剂,如α1抗胰蛋白酶(α1-AT)、分泌型白细胞蛋白酶抑制剂(SLPI)和Elafin.正常生理情况下,炎性损伤和抗炎性损伤两大因素处于动态平衡状态,但在支气管肺组织慢性炎性疾病时,该平衡受到破坏,促进疾病发生、发展.