Fenestrated blood vessels in craniopharyngioma

Summary The fine structure of two cases of craniopharyngioma was studied. Special attention was paid to the vasculature. The most striking finding is the presence of numerous fenestrae in the vascular endothelium. These structures are not present either in most parts of the normal brain or in skin, the organ which craniopharyngiomas most closely resemble. The origin of the fenestrae was discussed.     

Gangliosides in rabbit and human skeletal muscle with denervation atrophy

Summary In experimental denervation of rabbit skeletal muscle, an increase of gangliosides has been reported. Ganglioside, DNA, total lipid and protein levels were studied in experimental denervation of rabbit gastrocnemius muscle and in human skeletal muscle with denervation atrophy. In severe human denervation atrophy total ganglioside, DNA and total lipid levels were increased, and protein levels decreased as compared with controls. The ganglioside pattern was changed in severe human denervation atrophy and showed a significant increase of a G_T1b-like and moderate decrease of a G_M1-like compound. Findings in experimentally denervated rabbit muscle resembled results obtained in human denervation atrophy, showing a significant increase of total ganglioside levels as well as a moderate increase of G_T1b-like and decrease of G_M1-like compounds.

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Zusammenfassung In einer Publikation wurde berichtet, daß es nach experimenteller Denervierung des Kaninchenskelettmuskels zu einem Anstieg der Gangliosidkonzentration komme. Wir untersuchten Gangliosid-, DNS-, Gesamtlipidund Proteinkonzentrationen bei experimenteller Denervierung des Musculus gastrocnemius des Kaninchens und bei neurogener Atrophie des menschlichen Skelettmuskels.Bei schwerer neurogener Atrophie kam es zu einer statistisch signifikanten Zunahme der Gesamtgangliosid-, DNS-und Gesamtlipidkonzentration, während die Proteinkonzentration im Vergleich zu den Kontrollen signifikant abnahm. Das Gangliosidmuster bei schwerer neurogener Atrophie zeigte signifikante Zunahme eines G_T1b-ähnlichen bzw. eine relativ deutliche Abnahme eines G_M1-ähnlichen Gangliosids. Die Untersuchungen bei experimenteller Denervierung des Kaninchenskelettmuskels brachten ähnliche Ergebnisse wie bei der neurogenen Atrophie des Menschen: signifikante Zunahme der Gesamtgangliosidkonzentration, Zunahme des G_T1b-ähnlichen und signifikante Abnahme des G_M1-ähnlichen Gangliosids.

     

The occurrence of paracrystalline mitochondrial inclusions in normal human skeletal muscle

Summary Two different types of paracrystalline mitochondrial inclusions identical with or very similar to those already described in the literature for a variety of muscle diseases were found in human skeletal muscle biopsies obtained under general anesthesia before ischemia and after various periods of anoxia up to 150 min. As these crystalloids could be observed in seven of 14 healthy subjects and occurred in five of these seven cases either before or only 10 min after onset of ischemia, it is suggested that such mitochondrial inclusions develop not only under the influence of variant noxious stimuli, but may also represent a normal constituent of human skeletal muscle mitochondria.     

Heroin-induced myopathy in rat skeletal muscle

Summary The effects of heroin on rat skeletal muscle was studied. Heroin was injected intraperitoneally, and the soleus and tibial anterior muscles were studied using histological and histochemical techniques. Degenerative and regenerative changes were detected, the latter proving more significant. The soleus was the only muscle affected, the anterior tibial showing no sign of damage. The heroin myopathy model may be valuable in studying muscle fibre necrosis and regeneration.     

Nucleo-cytoplasmic ratio in ageing skeletal muscle

Summary In order to investigate possible changes in the nucleo-cytoplasmic ratio of the muscle fibres during ageing, samples of quadriceps femoris from 15 normal individuals whose age ranged from 17 to 82 years were studied (autopsy material). The mean lesser diameter and the number and size of the muscle fibre nuclei were calculated using a planimetric technique. It was found that nucleo-cytoplasmic ratio increased significantly after the age of 60 years. This was due to a decrease in the mean fibre size whilst the number and the size of myonuclei remained unchanged. The resemblance of this finding to denervation atrophy changes is noted.     

Perivascular siderophages in skeletal muscle from a patient with diabetic neuropathy

Summary Hemosiderin deposition in skeletal muscle histiocytes is uncommon but has been occasionally noted in hemochromatosis, hemosiderosis and Waldenstrom's macroglobulinemia. The purpose of this report is to describe the light microscopic and ultrastructural characterization of this abnormality in a patient with diabetes mellitus. A 56-year-old diabetic male presented with paresthesias and intermittent diffuse lower extremity myalgias. Neurologic examination was remarkable only for diminished vibratory sense in the toes, diminished deep tendon reflexes, and ankle-level stocking distribution hypalgesia. There was no clinical evidence of hemochromatosis and laboratory studies ruled out Waldenstrom's macroglobulinemia. Muscle biopsy showed modest variability in myofiber diameter with a few scattered angular atrophic type II fibers. There were numerous collections of granular pigment-containing histiocytes in endomysial and perimysial perivascular areas and marked thickening of blood vessels walls. The histiocytic pigment was bright blue with the Prussian blue stain. No pigment was seen in the myofibers. Ultrastructural examination revealed numerous perivascular histiocytes filled with hemosiderin containing granules of variable size and density and marked thickening of capillary walls with striking reduplication of basement membranes. A modest number of subsarcolemmal paracrystalline mitochondrial inclusions were present. X-ray dispersion analysis of the histiocytic pigment material confirmed the presence of iron in the lysosomal granules.     

骨骼肌细胞与热休克蛋白

背景：骨骼肌含有多种热休克蛋白,可能具有重要的生理功能。目的：综述骨骼肌热休克蛋白的特性,以及骨骼肌热休克蛋白在生理及病理情况下表达的意义。方法：以“热休克蛋白,骨骼肌,运动,缺血再灌注”为中文检索词,以“heat shock proteins, skeletal muscle, exercise, ischemia-reperfusion”为英文检索词,应用计算机检索Pubmed数据库和中文期刊全文数据库2010-06前发表的相关文章。纳入与骨骼肌细胞热休克蛋白研究相关的文献,排除重复性研究。结果与结论：共检索到197篇文献,排除无关重复的文献,保留35篇文献进行综述。目前研究证实骨骼肌含有多种热休克蛋白,主要有小热休克蛋白,热休克蛋白70,热休克蛋白60和热休克蛋白90等。热休克蛋白作为应激的指标,可以反映运动时细胞内发生的变化,对监控过度训练有重要意义。同时热休克蛋白在过度训练或肌肉损伤时对保持肌肉功能起重要作用。     

On the occurrence of the fenestrated vessels in Wallerian degeneration of the peripheral nerve

Summary Ultrastructural studies were made on the distal segments of the mouse phrenic nerve after crush injury. In the control, endoneurium contained only unfenestrated capillaries. In the experiment, from day 2 to day 6, endoneurial capillaries occasionally showed fenestrations with the attenuation of its cytoplasm. At this stage, axonal degeneration and myelin breakdown became evident showing early stage of Wallerian degeneration. In addition, detachment of the neighboring endothelial cells concomitant with the invasion of macrophage was also observed. These findings were previously unobserved changes of the endoneurial endothelium in Wallerian degeneration. The significance of the early occurrence of fenestrae was discussed briefly.     

Glomeruloid blood vessels in ethylnitrosourea-induced rat gliomas

Summary Glomeruloid blood vessels (GBVs), a characteristic histological feature of most human malignant gliomas, were recognized with high incidence in autochthonous rat gliomas induced by transplacental administration of ethylnitrosourea. To evaluate some of the biological properties of these GBVs, we carried out a study using histological methods and immunohistochemical staining for glial fibrillary acidic protein, factor VIII-related antigen (VIII Ag) and bromodeoxyuridine (BrdUrd). Of 22 animals with large, massively growing gliomas in the CNS, GBVs including conglomerate aggregations of small blood vessels with endothelial hyperplasia and strong VIII Ag expression were observed in 13 large gliomas histologically consisting of primitive neuroepithelial neoplasms (PNN; so called ependymoma) and mixed-type gliomas in combination with astrocytoma and PNN or anaplastic astrocytoma. The anaplastic gliomas in our series were devoid of GBVs. These findings indicate that GBV formation takes place in a histological variety of experimental gliomas. Furthermore, the GBVs were frequently associated with the vasculo-mesenchymal stroma in the parent gliomas, suggesting an intimate relationship with the morphogenesis of GBVs. In addition, it was shown that the GBVs had a higher BrdUrd-labelling index than that of other blood vessels in gliomas and also that of neoplastic cells in most parent gliomas, except for anaplastic gliomas. Based on these results, the possible mechanism of GBV morphogenesis is discussed with regard to the roles of macromolecules in the induction and regulation of GBVs.Supported in part by grants nos. 63570675 and 01480350 from the Ministry of Education, Science and Culture, Japan, and by a grant from the Ministry of Health and Welfare, Japan     

Changes in human skeletal muscles due to ageing

Summary Morphological changes in human skeletal muscle with ageing are reported. Samples from the deltoid and the vastus lateralis muscles from 126 subjects, aged 20–80 years, were studied by light microscopy. The patients died suddenly due to accidents or from fatal diseases. Until their death, they had preserved normal physical activity corresponding to their age. Chronic diseases, inactivity or neuromuscular diseases which are known to lead to changes in the muscles were excluded. The frequency of neurogenic changes of muscles increased with increasing age. These results correlated with electrophysiological and morphological changes in the peripheral nerves due to ageing reported by other investigators. The neurogenic changes in persons over 70 years were overlapped by a type-2 fibre atrophy.Supported by the Ministry of Public Health of the German Democratic Republic (HFR Schwangerschaft und frühkindliche Entwicklung, FR Genetische Defekte)     

In vivo assessment of catechol O-methyltransferase activity in rabbit skeletal muscle

With the use of microdialysis technique in the anesthetized rabbit, we examined the catechol O-methyltransferase (COMT) activity at the skeletal muscle interstitium. We implanted a dialysis probe into the adductor muscle, and monitored dialysate catecholamines and their metabolites with chromatogram-electrochemical detection. Administration of COMT inhibitor (entacapone) decreased dialysate 3-methoxy 4-hydroxyphenylglycol (MHPG) levels. Local administration of dihydroxyphenylglycol induced increases in dialysate MHPG levels. These increases in dialysate MHPG levels were suppressed by the addition of entacapone. The concentration of MHPG in the skeletal muscle dialysate corresponded to the COMT activity in the skeletal muscle. Furthermore, local administration of norepinephrine or epinephrine increased normetanephrine or metanephrine levels in dialysate but not MHPG levels. Skeletal muscle microdialysis with local administration of catecholamine offers a new method for in vivo assessment of regional COMT activity.     

Denervation-activated inward rectifier in frog slow skeletal muscle fibers

We tested whether the absence of an inward rectifier channel in slow skeletal muscle fibers of the frog is regulated by innervation. Normal and denervated slow fibers were identified according to their passive electrical properties. In current-clamp experiments, anomalous rectification was quantified as the ratio of effective resistances for hyperpolarizing and depolarizing pulses. In isotonic potassium solution, this ratio was 0.45 +/- 0.1 (n = 14) for twitch fibers, whereas slow fibers displayed linear behavior [ratio = 1.0 +/- 0.05 (n = 15)]. However, denervated slow fibers showed anomalous rectification (ratio, 0.48 +/- 0.07; n = 5). This finding was supported by voltage-clamp experiments in which denervated slow fibers displayed (1) an inward rectifier current during hyperpolarizing pulses, (2) an increase in this current when [K(+)](o) was increased, and (3) a current inhibition after application of Ba(2+). These results suggest that frog slow fibers, which normally do not possess inward rectifier channels, can express them after denervation.     

Streptokinase inhibits sympathetic neurotransmission in isolated blood vessels of the dog

A solid phase enzyme linked immunosorbent assay (ELISA) was developed for the quantitative determination of acquired inhibitors to factor IX. The IgG fraction of a sheep antiserum to factor IX was adsorbed to polystyren plates. After incubation with normal plasma as a factor IX source, the plates were incubated with serial dilutions of test plasma. The binding of human IgG antibodies to the factor IX-sheep anti factor IX complexes was detected by incubation of the plates with alkaline phosphatase conjugated antiserum to human IgG and addition of p-nitrophenyl phosphate as substrate. The absorbtion was read at 405 nm.Factor IX antibodies were detected by the ELISA in all of five examined plasma samples from patients with hemophilia B and acquired inhibitors to factor IX. The titres as determined in the ELISA were well in agreement with the titres as determined in a coagulation assay (0.1–800 units/ml). The ELISA was negative in plasma from 13 patients with hemophilia B and no detectable inhibitor in a coagulation assay, and in plasma from four patients with hemophilia A and acquired inhibitors to factor VIII.     

Parkin expression in human skeletal muscle

Parkin is known to be present in human neurons and peripheral nerves. Using an antibody against parkin protein we have now demonstrated that parkin is also expressed in the sarcoplasm and sarcolemmal region of human skeletal muscle fibres. We have also found different age-related patterns of expression with increase in intensity and organization of distribution at older ages. These findings suggest a change in the functional role of parkin in skeletal muscle with ageing and may contribute to understanding the mechanisms of muscle aging.     

Pathology of skeletal muscle and intramuscular nerves in infantile neuroaxonal dystrophy

Summary Biopsies of the biceps muscle and sural nerve were taken from a girl aged 2 years with infantile neuroaxonal dystrophy (INAD).In addition to the typical axonal spheroid bodies in a number of the i. m. nerve fibers, the neuromuscular junctions (NMJs) and motor nerve endings also contained axonal swellings. The sural nerve, except for three dystrophic fibers, was almost completely normal.A teased nerve preparation showed four additional abnormal fibers with focal axonal enlargement similar to those in giant axonal neuropathy (GAN).These results suggest that a biceps muscle biopsy may be more useful than a sural nerve biopsy for the diagnosis of INAD, because the muscle contains abnormal peripheral nerves and NMJs in high frequency.     

骨骼肌的运动适应机制

背景：骨骼肌运动适应机制的研究对提高运动成绩,预防和治疗一些代谢紊乱性疾病具有重要意义。 目的：探讨骨骼肌运动适应的机制。 方法：应用计算机检索PubMed数据库和中文期刊全文数据库2011-03前发表的相关文章,检索词分别为“skeletal muscle, exercise, adaptation, cytoskeleton, dystrophin”和“骨骼肌,运动,适应,骨架蛋白,肌营养不良蛋白”,共检索到56篇文献,纳入所述内容与骨骼肌运动适应机制相关的文献,排除重复性研究,保留31篇进行综述。 结果与结论：激烈的运动使肌肉结构和细胞代谢产生应激反应,包括肌肉损伤和氧化应激反应。高强度的离心运动可造成肌肉超微结构损伤,但运动性肌损伤后存在肌肉再重建反应。运动训练可促进健康的个体对一氧化氮系统产生各种各样的适应,通过各种机制增强骨骼肌的生物学有效性,这些适应性变化可有效增加运动能力,对心血管系统具有保护作用。目前,大多数人类骨骼肌运动适应机制还没有被发现。     

肌肉特异性microRNAs在骨骼肌损伤修复过程中的动态表达

目的探讨3种肌肉特异性microRNAs(miRNAs):miR-1、miR-133和miR-206在骨骼肌损伤修复过程中在肌肉组织中和血清中的动态表达。方法局部注射0.75%盐酸布比卡因(BPVC)制作小鼠腓肠肌损伤模型,采用Real Time RT-PCR方法检测注药后不同时间点3种miRNAs在肌肉组织中和血清中的表达量。结果小鼠一侧腓肠肌注射BPVC后,该侧后肢的活动能力明显较对侧下降;肌肉组织中miR-1、miR-133和miR-206的表达水平均于注射BPVC后先下降后明显上升、维持一段时间后又恢复至接近注药前水平;正常小鼠血清中3种miR-NAs的表达量均很低;血清中miR-1、miR-133和miR-206均于肌肉注射BPVC后早期表达上调,其中miR-1于注药后6～12h表达上调,miR-133于注药后6～24h表达上调,而miR-206于注药后6h表达轻微增高。结论对C57BL/6小鼠而言,局部注射60μl BPVC可制作出稳定的腓肠肌损伤模型,肌肉特异性miRNAs可能在骨骼肌的再生过程中发挥了一定调控作用,有望成为肌肉疾病的潜在治疗靶点;骨骼肌损伤时释放miRNAs到血清中,肌肉特异性miRNAs有望作为肌肉疾病的诊断指标之一。     

Myasthenia gravis antibodies to skeletal muscle cell surface antigens

Sera from 28 of 137 patients with myasthenia gravis (MG) (i.e. 20%) contained antibodies which stained the surface of skeletal muscle cells in an indirect immunofluorescence test. Forty of the 137 sera (i.e. 30%) contained cross-striational antibodies. Absorption experiments showed that the antibodies staining the muscle cell surface were different from those staining the cross-striational bands. Twenty of the sera (i.e. 15%) contained antibodies which agglutinated sheep erythrocytes (SE) coated with a citric acid extract of skeletal muscle (CAE). These antibodies were closely associated with the presence of a thymoma. There was a positive correlation between the antibodies agglutinating CAE-coated SE and those staining the muscle cell surface. Absorption experiments indicated that the antibodies to CAE were directed against muscular antigens located in or near the sarcolemma.     

Differential expressions of protein kinase C isozymes during proliferation and differentiation of human skeletal muscle cells in vitro

The mechanism of skeletal muscle regeneration in vivo can be well modeled in vitro by culturing skeletal muscle cells. In these cultures mononuclear satellite cells fuse to form polynuclear myotubes by proliferation and differentiation. The aim of this study was to determine how the different protein kinase C (PKC) isozymes were expressed during differentiation of human skeletal muscle in vitro. The expressions of desmin, used as a muscle-specific intermediate filament protein marker of differentiation, and of different PKC isozymes were detected by single and double immunohistochemical labeling, and by Western blot analysis. In skeletal muscle cells we could identify five PKC isozymes (PKCα, -γ, -η, -θ and -ζ). The expressions of PKCα and -ζ did not change significantly during differentiation; their levels of expression were high in the early immature cells and remained unchanged in later phases. In contrast, the expression levels of PKCγ and -η increased with differentiation. Furthermore, the cellular localization of PKCγ markedly altered during differentiation, with a perinuclear-nuclear to cytoplasmic translocation. The change in the level of expression of PKCθ during differentiation showed different pattern; its expression was high during the early phases, but a decreased immunostaining was detected in the matured, well-differentiated myotubes. We conclude, therefore, that cultured human skeletal muscle cells possess a characteristic PKC isozyme pattern, and that the different phases of differentiation are accompanied by different expression patterns of the various isozymes. These data suggest the possible functional and differential roles of PKC isozymes in human skeletal muscle differentiation. Received: 28 February 1999 / Revised, accepted: 24 June 1999