Histochemistry and electron microscopy of muscle fibres in a case of congenital paramyotonia

Summary In a case of congenital paramyotonia a muscle biopsy was performed and studied morphologically, histochemically and ultrastructurally. A clearcut pattern of changes has been observed with ATPase and oxidative enzymes. On electron microscopy special changes known as tubular aggregates were found. The relationship between the two findings, as well as the significance of such alterations in the range of periodic paralyses and myotonic phenomena, are discussed.

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Zusammenfassung Bei einem Fall von kongenitaler Paramyotonie wurde eine Muskelbiopsie lichtmikroskopisch, histochemisch und elektronenoptisch untersucht. Typische Veränderungen ergaben sich in der ATPase-Färbung und in bezug auf oxydative Enzyme. Bei der elektronenoptischen Untersuchung wurden sogenannte tubuläre Aggregate festgestellt. Es wird die Beziehung der zwei Gruppen von Veränderungen zueinander diskutiert sowie auch die Bedeutung derselben im Rahmen der periodischen Lähmungen und der myotonen Phänomene.

     

RA 642, a pyrimido-pyrimidine-derivative with vasodilating and hypertensive potency

Summary 2,2-[(4,8-bis(diethylamino)-pyrimido [5,4-d]-pyrimidine-2,6-diyl)di-(2-methoxyethyl)imino]diethanol), RA 642, combines hypertensive and vasodilating effects. In anaesthetized animals arterial blood pressure was increased by i.v. doses of 0.25–4 mg/kg in cats and 0.025–0.25 mg/kg in dogs. In conscious dogs, 25 mm increase of mean blood pressure was achieved with 0.2 mg/kg i.v. and 18.8 mg/kg p.o. Cerebral blood flow was enhanced and calculated cerebral vascular resistance was reduced by RA 642. Total peripheral resistance was diminished by 0.25–1.0 mg/kg i.v. A vasodilatation of femoral and coronary vessels was shown after intraarterial injection. This effect as well as a BaCl₂-antagonism in the isolation ileum is explained by a papaverine-like relaxant effect on smooth muscle. Activity on peripheral adrenergic receptors was excluded. Hypertension was abolished in spinalized cats, indicating a central mechanism of this effect.     

Expression of c-fos-like immunoreactivity in the feline brainstem in response to isometric muscle contraction and baroreceptor reflex changes in arterial pressure

This study compared whether activation of muscle ergoreceptor afferents caused by isometric muscle contraction, activation of baroreceptor afferents induced by i.v. infusion of phenylephrine, or baroreceptor afferent inactivation, caused by carotid artery occlusion, elicit similar patterns of c-Fos induction in brainstem areas. Adult cats were anesthetized with alpha-chloralose, and in each case, the experimental intervention caused an increase in the arterial blood pressure. There were two sets of control experiments: in both, animals underwent the same surgical procedures but then either remained at rest for the entire study, or the tibial nerve was stimulated, as in the contraction group, following muscle paralysis with tubocurarine. Following the procedures, animals rested for 90 min to allow neuronal expression of c-Fos. Control cats showed very little c-Fos immunoreactivity (c-Fos-ir) in the brainstem. Muscle contraction induced c-Fos-ir expression mainly in the nucleus tractus solitarius, lateral reticular nucleus, lateral tegmental field, vestibular nucleus, subretrofacial nucleus, spinal trigeminal tract and in a lateral region of the periaqueductal grey (P 0.5-1.0). The majority of the c-Fos-ir was found in brainstem areas contralateral to the contracted muscle. In addition, muscle contraction induced c-Fos-ir in the dorsal horns of spinal segments L6-S1 on the ipsilateral side of the spinal cord. Phenylephrine infusion caused c-Fos-ir expression in the nucleus tractus solitarius, spinal trigeminal tract, solitary tract, and dorsal motor nucleus of the vagus. No c-Fos-ir was apparent in the periaqueductal grey. Carotid occlusions induced c-Fos-ir expression in the area postrema, nucleus tractus solitarius, solitary tract, and spinal trigeminal tract. Expression was bilateral. Areas that exhibited c-Fos-ir correspond to sites previously reported to release various neuropeptides in response to muscle contraction or carotid occlusions. These results indicate that the exercise pressor reflex and baroreflex activate similar, but not completely identical, sites in the brainstem.     

An in vitro model for videoimaging of human bladder smooth muscle cell contractions

Knowledge regarding human bladder smooth muscle cell (SMC) physiology is very limited. Only a few specific medical therapies for bladder disorders have therefore been established. The objective of this study was to develop a model for videomicroscopy of bladder SMC contractions. Cells were isolated from human cystoprostatectomy specimens and cultured in a modified EMEM medium. These cells were identified as SMCs by means of immunohistochemistry. For videomicroscopy, the culture flasks were coated with a viscous agent to allow cell contraction. Contractions were visualized by means of a cell culture microscope with a time-lapse videosystem. For cholinergic stimulation of the cells, acetylcholine, in concentrations ranging from 100 μM to 10 mM, was applied. The percentage of contracting cells within the observation field was evaluated for quantitative analysis. In control experiments without contractile stimulant 6% of the cells were observed to contract. Stimulation with acetylcholine induced a significant dose-dependent increase to 47% in contracting cells. These results demonstrated that videomicroscopy is an appropriate tool to investigate the contraction mechanisms of bladder SMCs. This model offers the possibility of studying drug effects on the human detrusor in vitro. Received: 16 September 1999 / Accepted: 1 May 2000     

Reversed palmaris longus muscle on MRI: report of four cases

Muscle anomalies around the wrist, in particular the palmaris longus muscle, may cause effort-related median nerve compression. A search of the medical records at our university hospital between 1994 and 1999 revealed four patients with an effort-related median nerve compression due to a reversed palmaris longus muscle. Magnetic resonance imaging was used in the patient work-up and showed an anomalous muscle in each case that had been missed initially. All four patients were free of pain after simple excision of the anomalous muscle. Awareness of muscle anomalies at the wrist on MR imaging is essential in evaluating patients with nerve compressions at the wrist. The purpose of this article is to heighten this awareness in radiologists. Received: 23 June 1999; Revised: 30 September 1999; Accepted: 24 December 1999     

硝普钠诱导体外哮喘大鼠支气管平滑肌细胞凋亡

目的观察一氧化氮(NO)供体硝普钠(SNP)是否诱导哮喘大鼠气道平滑肌细胞(ASMCs)凋亡。方法W istar大鼠10只,用卵白蛋白作为致敏原建立大鼠哮喘模型,分离出大鼠的气道平滑肌细胞,用SNP(NO的供体)干预,通过四甲基偶氮唑蓝(MTT)法测定细胞生长率的变化,用原位末端标记法和流式细胞术检测SNP对哮喘大鼠气道平滑肌细胞细胞凋亡的影响。结果⑴MTT法测定:SNP 哮喘组的细胞抑制率明显高于哮喘组细胞存活率,(n=8,P<0.05),且呈浓度依赖关系。⑵TUNEL(原位末端标记)法检测:SNP 哮喘组的凋亡指数明显高于哮喘组,(n=4,P<0.05)。⑶流式细胞术测定SNP 哮喘组的平滑肌细胞凋亡率明显高于哮喘组,(n=4,P<0.05)。结论硝普钠能抑制哮喘大鼠气道平滑肌细胞的增殖,并且能诱导哮喘大鼠气道平滑肌细胞的凋亡,这种作用可能与治疗哮喘的气道重建有关。     

全反式视黄酸对体外培养的人体大隐静脉内膜平滑肌细胞增殖与凋亡的影响

目的研究全反式视黄酸(atRA)对体外培养的人体大隐静脉内膜增厚、平滑肌细胞增生与凋亡的影响。方法30小段(1 cm长)人体大隐静脉(HSV),随机分成HSV组、atRA组和对照组(n=10),atRA组和对照组均体外培养14 d。atRA组:培养液中含atRA100μM;对照组:培养液中含同等量无水酒精(atRA溶剂)。对HSV组及培养后的atRA组、对照组标本进行取材固定,M asson染色,免疫组化测定增殖细胞核抗原(PCNA)及TUNEL法检测平滑肌细胞凋亡,计算机图象分析仪测量血管内膜厚度、计算内膜增生指数及细胞增殖和凋亡百分比。结果体外培养人体大隐静脉能产生明显的内膜增生和平滑肌细胞增殖(P<0.05);atRA组内膜厚度、增生指数及PCNA阳性细胞百分数均明显低于对照组(P<0.05)。而凋亡细胞百分数则明显高于对照组(P<0.05)。结论atRA可以抑制体外培养人体大隐静脉内膜增厚及平滑肌细胞增生,促进平滑肌细胞凋亡。     

手针与电针对急性运动大鼠骨骼肌线粒体的影响

目的:研究手针和电针对急性游泳运动大鼠骨骼肌线粒体的抗氧化酶活性、Ca2 含量、Ca2 -ATP酶活性的影响,探讨针刺提高运动能力的作用机制.方法:将SD雄性大鼠随机分为4组.手针组和电针组在急性游泳运动前运用手捻针和电针两种不同的方法进行刺激,运动后处死取材;对照组在安静状态下、游泳组在急性游泳运动后处死取材,测定有关指标.结果:急性游泳运动后游泳组大鼠骨骼肌线粒体的谷胱甘肽过氧化物酶(GSH-Px)活性、Ca2 -ATP酶活性与对照组相比较有显著性下降(P<0.05),Ca2 含量明显上升(P<0.01).手针组可以明显提高急性游泳运动后大鼠骨骼肌线粒体超氧化物歧化酶活性(P<0.05);手针组与游泳组比较,GSH-Px活性、Ca2 -ATP酶活性有显著性升高(P<0.05).游泳组、电针组Ca2 含量均比对照组明显升高(P<0.01).结论:针刺可保护细胞免受急性运动所致的损伤,维持线粒体的某些功能,从而延缓疲劳,延长肌肉工作时间,预防骨骼肌损伤.而电针的作用似乎不明显.     

A pilot study using magnetic resonance imaging to determine the pattern of muscle group recruitment by rowers with different levels of experience

Objective. To determine whether it was possible using magnetic resonance imaging (MRI) to define the pattern of muscle recruitment in a specific sport (rowing) and to see whether there were differences in this pattern between athletes of different experience. Design and method. It has been shown that during vigorous exercise the water content of muscle increases transiently. This can be observed using MRI, where the prolonged T2 relaxation time of muscle can be demonstrated. In this study we have exploited the increase in signal seen in exercised muscle on short TI inversion recovery (STIR) sequences, to show how rowers of different experience use different muscle groups. Results.We have shown that trained athletes recruit selected muscle groups to carry out a given task, which they carry out more efficiently than untrained or less experienced athletes. Conclusion.We have provided the basis of potential research to refine training methods, in order to develop specific muscle groups in athletes, in the hope of achieving a higher level of performance at an earlier stage in their training. We have also defined a technique that may be of clinical value in cases of muscle dysfunction. Received: 13 September 1999 Revision requested: 19 November 1999 Revision received: 30 December 1999 Accepted: 4 January 2000     

Erdheim-Chester disease with intramuscular lipogranuloma

We report on a rare manifestation of Erdheim-Chester disease with intramuscular lipogranuloma. The patient was a 66-year-old man who noted a soft tissue mass in the right quadriceps femoris muscle. Radiographs revealed symmetrical osteosclerosis in the diametaphysis of both femora and tibiae. An open biopsy revealed a proliferation of lipid-laden histiocytes in the femoral bone marrow and the quadriceps femoris muscle. To our knowledge, this is the second case of Erdheim-Chester disease involving muscle. Received: 4 October 1999 Revision requested: 18 November 1999 Revision received: 1 December 1999 Accepted: 2 December 1999