带腹直肌蒂胸骨翻转术治疗漏斗胸10例疗效分析

目的:探讨漏斗胸的外科治疗。方法:应用带腹直肌蒂胸骨翻转术对10例漏斗胸病人进行外科治疗。结果:本组病例手 术效果满意,术中翻转胸骨片血运丰富,术后长期随诊,无复发。结论:带腹直肌蒂胸骨翻转术治疗漏斗胸具有手术操作简便、出血少、 术后恢复快、矫正效果满意、术后无复发等特点。     

葛根素对抗H2O2引起血管平滑肌细胞凋亡及坏死

目的：研究葛根素对过氧化氢引起无血清培养的小牛主动脉血管平滑肌细胞凋亡和坏死的影响。方法：通过体外细胞培养，以噻唑兰（MTT）法测定细胞存活率，用流式细胞术检测细胞DNA含量及凋亡细胞百分率；DNA琼脂糖凝胶电泳法观察细胞凋亡过程中DNA断裂程度。结果：H2O2诱导无血清培养的平滑肌细胞凋亡，葛根素可显著降低平滑肌细胞中凋亡细胞百分率，并减少凋亡细胞DNA断裂，同时也减少其引起的平滑肌细胞坏死。结论：葛根素可对抗H2O2引起的无血清培养的血管平滑肌细胞凋凋亡及坏死。     

尾部悬吊与30月龄大鼠比目鱼肌的形态学特征比较

目的 观察尾部悬吊和30月龄大鼠比目鱼肌发生萎缩过程的异同点.方法 SD雄性大鼠42只,随机分为7组,即尾部悬吊5 d、7 d、14 d组,相应的同步对照和30月鼠龄组,在各时间点制备比目鱼肌横截面冰冻切片标本,用抗MHC Ⅱ单克隆抗体进行免疫组织化学染色,计算比目鱼肌Ⅰ、Ⅱ型肌纤维横截面积并计数各型肌纤维数目.结果 与同步对照组相比,悬吊组大鼠比目鱼肌的湿重,相对湿重,Ⅰ、Ⅱ型肌纤维横截面积,经体重归一化的肌纤维横截面积均显著降低,Ⅱ型肌纤维比例显著增加,而Ⅰ型肌纤维比例减少.与14 d对照组相比,30月龄组大鼠比目鱼肌湿重和Ⅰ、Ⅱ型肌纤维横截面积均明显增大,但其相对湿重和经体重归一化的肌纤维横截面积却显著降低,与悬吊14 d组无显著差异.30月龄组大鼠比目鱼肌中Ⅰ、Ⅱ型肌纤维比例与各对照组相比亦无显著差异.结论 30月龄大鼠比目鱼肌萎缩以首先出现相对湿重与归一化肌纤维横截面积降低为特征,且发生较慢,而尾部悬吊大鼠比目鱼肌则在较短时间内发生全面萎缩.     

钾通道开放剂降低血管平滑肌细胞内游离钙浓度(英文)

目的:研究PCO—Pin,Nic,Lem及RP对VMSC内[Ca~(2 )]_i的改变及其可能机制。方法:VSMC加入Fura-2 AM 2.5μmol·L~(-1)37℃下孵育50min,[Ca~(2 )]_i用荧光分光光度计检测。结果:4种PCO能较弱地抑制K~ 30 mmol·L~(-1)诱导的[Ca~(2 )]_i增加,但明显抑制ATP 0.1mmol·L~(-1)诱导的[Ca~(2 )]_i峰相及持续相增加,且呈剂量依赖性。格列苯脲完全阻断Pin,Lem及RP的作用,只部分抑制Nic的作用。无钙液中先给4种PCO,能显著抑制ATP诱导的[Ca~(2 )]_i峰相增加。结论:4种PCO均抑制ATP诱导的[Ca~(2 )]_i增加,此作用与减少细胞外钙内流及细胞内钙释放有关。     

Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping

Belli , A. & Bosco, A. 1992. Influence of stretch-shortening cycle on mechanical behaviour of triceps surae during hopping. Acta Physiol Scand 144 , 401408. Received 20 March 1 991 , accepted 3 December 1991. ISSN 0001–6772. Laboratories of Physiology, Universities of St Etienne and Lyon, France and Departments of Biology and Physical Activity, University of Jyväskylä, Finland. Six subjects performed a first series of vertical plantar flexions and a second series of vertical rebounds, both involving muscle triceps surae exclusively. Vertical displacements, vertical forces and ankle angles were recorded during the entire work period of 60 seconds per series. In addition, expired gases were collected during the test and recovery for determination of the energy expenditure. Triceps surae was mechanically modelled with a contractile component and with an elastic component. Mechanical behaviour and work of the different muscle components were determined in both series. The net muscular efficiency calculated from the work performed by the centre of gravity was 17.5±3.0% (mean ± SD) in plantar flexions and 29.9 ± 4.8% in vertical rebounds. The net muscle efficiency calculated from the work performed by the contractile component was 17.4 %% 2.9% in plantar flexions and 16.1 ± 1.47; in vertical rebounds. These results suggest that the muscular efficiency differences do not reflect muscle contractile component efficiency but essentially the storage and recoil of elastic energy. This is supported by the relationship (P < 0.01) found in vertical rebounds between the extra work and the elastic component work. A detailed observation of the mechanical behaviour of muscle mechanical components showed that the strategy to maximize the elastic work depends also on the force-velocity characteristics of the movement and that the eccentric-concentric work of the contractile component does not always correspond respectively to the ankle extension-flexion.     

High proportion of type I fibres in thigh muscle of young dancers

A previous study showed that adult female dancers have a high percentage of type I fibres in vastus lateralis. similar to that of endurance-trained female runners ar female cross-country skiers. It is not known if dancers already at an early age are characterized by a high percentage of type I fibres or develop a high percentage of type I fibres as a consequence of dance training. Furthermore. the muscle fibre composition of male dancers has not previously been studied. Therefore the aim of the study was to analyse skeletal muscle fibre characteristics in 10-year-old and 20-year-old dancers of both sexes. Age-matched boys and girls whose physical activity was average for their age groups served as controls. Muscle biopsies for histochemical analysis were obtained from vastus lateralis using the percutaneous needle technique. The major finding of the present study was that the vastus lateralis of young dancers of both sexes had a higher percentage of type I fibres than that of controls. Moreover. the higher type I percentage was seen not only in 20 year aids. but also in 10 year aids. who had begun their dance training at a professional level only a few weeks earlier. No significant difference in this respect was found between female and male dancers. In conclusion. the muscle fibre type composition in young dancers of both sexes differs from that of the average individual of the same age and is characterized by a high percentage of type I fibres.     

Mechanisms of pinacidil-induced vasodilatation

The mechanism of the vasodilator effect of pinacidil was examined. Pinacidil (0.1–100 μM) inhibited the increases in cytosolic Ca²⁺ ([Ca²⁺]_i) and muscle tension due to norepinephrine in rat aorta. In contrast, a Ca²⁺ channel blocker, verapamil, inhibited the norepinephrine-stimulated [Ca²⁺]_i more strongly than the contraction. Higher concentrations of pinacidil (3–100 μM) inhibited the verapamil-insensitive portion of the contraction and [Ca²⁺]_i. An inhibitor of ATP-sensitive K⁺ channels, glibenclamide, antagonized the inhibitory effect of low concentrations ( 10 pM) of pinacidol. Pinacidil did not change the contraction induced by Ca²⁺ in vascular smooth muscle permeabilized with Staphylococcus aureus -toxin. Norepinephrine (in the presence of GTP), 12-deoxyphorbol 13-isobutyrate (in the absence of GTP), and treatment with GTP_γS potentiated the contraction of permeabilized smooth muscle induced by the addition of Ca²⁺. Pinacidil (100 μM) inhibited the potentiation due to GTP_γS or noepinephrine but not to phorbol ester. These results suggest that pinacidil has dual effects on vascular smooth muscle contraction. At lower concentrations (>0.1 μM), it decreases [Ca²⁺]_i, possibly by activating ATP-sensitive K+ channels. At higher concentrations (> 3 μM), it may additionally inhibit the receptor-mediated, GTP-binding protein-coupled phosphatidyl inositol turnover.     

Substantial inhibition of neo-intimal response to balloon injury in the rat carotid artery using a combination of antibodies to platelet-derived growth factor-BB and basic fibroblast growth factor

Thirty percent of patients undergoing percutaneous transluminal coronary angioplasty develop recurrent disease within a year. This is usually due to the rapid accumulation of intimal smooth muscle cells and extracellular matrix, which causes luminal narrowing, and is probably orchestrated by several mitogenic and chemotactic factors, of which platelet-derived growth factor (PDGF) and basic fibroblast growth factor (bFGF) appear to be particularly important. We have investigated the effects of administering a combination of neutralizing antibodies directed against PDGF-BB and bFGF on neo-intima development following balloon catheter injury in the rat carotid artery. Purified sheep anti-PDGF-BB and anti-bFGF immunoglobulins (IgGs) were administered singly and in combination prior to mechanical injury and daily until sacrifice, 8 days later. Plasma titres of exogenous anti-PDGF-BB and anti-bFGF were maintained at levels 10–20-fold higher than those required to neutralise the mitogenic and chemotactic effects of 20 ng/ml of PDGF-BB, or 10 ng/ml bFGF in vitro. Used singly, anti-PDGF IgG treatment was associated with a 47% reduction in intimal thickness and a 59% reduction in intimal:medial area ratio; anti-bFGF IgG administration caused a 53% reduction in intimal thickness, and a 50% reduction in intimal:medial area ratio. Treatment with a combination of these antibodies resulted in a 83.8% reduction in intimal thickness (P<0.05), and a 91% reduction in intimal:medial area ratio (P<0.01). The latter treatment was also associated with a significantly higher intimal cell density (14.2±1.6×10³ nuclei/mm²) compared to animals receiving non-immune IgG (7.8±0.8×10³ nuclei/mm²; P<0.025), although intimal and medial cell proliferation indices were not significantly different between the groups (P>0.05). Our results suggest that in this particular model, PDGF-BB and bFGF are the major factors controlling neointimal hyperplasia, and that these growth factors are operating principally via an effect on smooth muscle cell migration and extracellular matrix protein accumulation.     

Simultaneous measurement of intracellular pH and contraction in uterine smooth muscle

Changes in intracellular pH (pH_i) are thought to produce large changes in force production in the uterus. There have however, been no simultaneous measurements of pH_i and force in the uterus and therefore no direct information is available about the relation between the two. We have used carboxy-SNARF (a pH-sensitive fluorophore) in small strips of longitudinal myometrium and obtained simultaneous measurements of pH_i and force. SNARF did not alter contractile function, and continuous measurements of pH_i could be made for 2 hours. The mean resting pH_i (7.16) was similar to that reported previously. Application of weak bases rapidly raised pH_i, in a concentration-dependent manner, followed by a gradual restoration of pH_i to resting levels. Alkalinization greatly increased the frequency of contractions, often accompanied by a small increase in their amplitude. Removal of base produced a rebound acidification which transiently abolished contractions. Direct acidification of the cytoplasm, by application of weak acid, also abolished contractions. However the alkalinization which accompanied removal of acid, produced variable effects on force.Supported by the M.R.C.     

汞对人体必需元素干扰的研究

对42例汞吸收、2例汞中毒者(尿汞>99.7nmol/L),采用原子吸收光谱法,检测了汞对人体必需五种金属元素代谢的干扰。研究发现,汞时人体必需元素镁、铜具有拮抗作用。汞吸收者血清镁极显著低于对照组(P>0.01)。经驱汞治疗后,血清镁、铜自然上升与对照组无统计学差异(P>0.05),镁离子低下,可出现神经肌纤维兴奋性增高。由此推测,汞引起肌肉震颤的毒理,可能由汞拮抗镁离子低下引起。设想,对汞中毒者采用补镁制剂治疗,是否具有驱汞作用值得探讨。