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Biomedical subjects

S M Chou

Publications and source records attributed to S M Chou.

At least 73 records · Page 4Linked to original sources
PubMed1982

Involvement of the Onuf nucleus in Werdnig-Hoffmann disease.

Contrary to contention that Onuf nucleus is spared in Werdnig-Hoffmann disease (WHD) as it is in ALS, we found central chromatolysis in the Onuf neurons of the sacral cord from all five WHD patients. They were less depopulated but the central chromatolysis appeared more frequently than in anterior motor neurons. In contrast, the sacral autonomic neurons were not affected in any of the five cases. This argues against the view that the Onuf nucleus is autonomic and is spared with other autonomic neurons.

Anterior Horn Cells↗
PubMed1981

Nasal glioma.

An 11-month-old girl had a congenital extracranial frontonasal glioma. The tumor was attached to the left membranous septum and excised by a simple ellipse and stalk dissection. The tumor is considered to arise from ectopic neuroectodermal tissue projected through the foramen cecum into the developing nasofrontal cranium and sequestered there on closure of the cranial sutures. Light microscopy demonstrated tumor tissue composed of fibrocollagenous septae separating interspersed glial cell islets and scattered hypoplastic skeletal muscle cells. Electron microscopy disclosed slender but differentiated muscle cells. No neuronal components could be identified. The heterotopic neuroglial nodules seemingly grew and differentiated by intermingling with either growing mesodermal cells or striated muscle cells or by transformation of some neuroglial elements into striated muscle cells. This extranasal glioma would best be classified as a benign congenital extranasal neuroectodermal tumor.

Diagnosis, Differential↗
PubMed1981

Preservation of the phrenic motoneurons in Werdnig-Hoffmann disease.

A neuropathological study on spinal cords at the third, fourth, and fifth cervical levels in 4 patients with Werdnig-Hoffmann disease revealed marked, generalized loss of motoneurons except for a cluster of large or medium-sized ones in the most medial portion of the anteromedial cell group. These well-preserved neurons were regarded as the phrenic motoneurons because diaphragmatic movement was the only muscle activity that remained until the last stage of illness. Furthermore, in its location and its cytoarchitectonic and neuronal characteristics, this neuronal cluster coincides with the phrenic nucleus as previously localized in the spinal cords of patients with phrenicotomy.

Female↗
PubMed1981

A new model of congenital hydrocephalus in the rat.

Hydrocephalic neonates were observed in a small breeding colony of rats. Normal rats from this colony were obtained and brother-sister mated for seven generations. The overall prevalence of hydrocephalics was approximately 23%; however, in one subline, the prevalence approached 50%. Breeding data suggested the trait to be polygenic. Hydrocephalics could be detected at 1-2 days of age, and survived for 4-5 weeks. Dilatation of the ventricles was restricted to the lateral ventricles. No evidence of developmental anomalies was seen within the ventricles. Preliminary evidence suggested that the pathophysiology may be related to poorly developed veins in the periosteal-dural layers and to underdeveloped pia-arachnoid cells. The hydrocephalus was classified as being of the communicating type.

Age Factors↗
PubMed1981

Ultrastructural abnormalities and perifascicular atrophy in childhood dermatomyositis with special reference to transverse tubular system-sarcoplasmic reticulum junctions.

Comparison of ultrastructural abnormalities between perifascicular and centrofascicular myofibers was made in the same muscle fascicles from six patients with childhood dermatomyositis. Consistent abnormalities are seen at the junctional sites between the transverse tubular system (TS) and sarcoplasmic reticulum (SR) as visualized by lanthanum staining. Early conical dilations at the TS-SR junctions have progressed to become connected with large cylindrical or spheroid channels representing SR. These TS-SR anastomoses are far more extensive in the perifascicular than in the centrofascicular myofibers. Honeycomb TS proliferations suggestive of a repair process occasionally occur at the sites of TS-SR anastomoses. These alterations precede myofibrillar derangements and they may be related to the primary pathogenetic process involved in dermatomyositis. It is postulated that leakage of degraded structural protein molecules through TS-SR anastomoses may lead to the perifascicular atrophy seen on light microscopy.

Adolescent↗
PubMed1980

Anastomoses of transverse tubules with terminal cisternae in polymyositis.

Abnormal transverse or T tubules spatially continuous with sarcoplasmic reticulum (SR), as visualized with a lanthanum (La) tracer, were found in biopsy specimens from nine patients with polymyositis whose serum enzyme (creatine phosphokinase [CPK]) levels were elevated before the time of biopsy. On comparison with the T system in more than 50 control subjects without CPK elevation, it became apparent that presumed anastomoses of T tubules with SR were the most consistent anatomical correlates of the enzyme leakage. Two types of anastomoses were seen on the basis of passage of La: first, early segmental dilation of T tubules and perpendicular continuations with SR; and second, focal proliferation of T tubules forming "T tubule networks" and then anastomosing with SR at the periphery of the networks. The latter is considered to be a concurrent repair process for the injured triads. Lanthanum did not penetrate freely through the plasma membrane of necrotized muscle fibers. It is concluded that junctional sites between T tubules and SR may be the primary sites of leakage of sarcoplasmic enzymes in polymyositis.

Adolescent↗
PubMed1980

Localization of the phrenic nucleus in the rat: a HRP study.

The localization of the phrenic nucleus in the rat spinal cord was studied with the horseradish peroxidase (HRP) method. After injection of HRP into the hemidiaphragm, labeled neurons were localized in a distinct nucleus between the ventromedial and ventrolateral cell groups of the ventral horn, with a longitudinal extension from the rostral 3rd to 5th cervical segments. Labeled neurons were oval or round in shape, medium-sized and tightly clustered. Labeled neurons were found in a well-defined cell column parallel to the longitudinal axis of the cervical spinal cord in frontal sections.

Animals↗
PubMed1980

Transmission and scanning electron microscopy of spongiform change in Creutzfeldt-Jakob disease.

Brains from three human cases of Creutzfeldt-Jakob disease and three monkey cases of transmitted Creutzfeldt-Jakob disease were examined. Spongiform change was present in all cases on both light and electron microscopic examination. Electron microscopic examination revealed membrane alterations within vacuoles in all cases. On SEM, both ulcerated and focally thickened membranes were apparent; TEM revealed splitting of unit membranes as well as focally thickened amorphous membranes. Small blisters with 70 to 150 nm particulates were seen on membranes in SEM. TEM revealed 10 nm electron-dense particles which might be either part of the infectious agent or a membrane alteration caused by it. The significance of these findings was discussed.

Adult↗
PubMed1979

Neuropathology of "spinning syndrome" induced by prenatal intoxication with a PCB in mice.

A striking motor dysfunction, "spinning syndrome," developed with a high frequency in weaning mice whose dams received oral 3,4,3',4'-tetrachlorobiphenyl (4-CB) during gestation (day 10 through day 16). The syndrome is permanent and is characterized by swift circling movements sustained in one direction at a minimal rate of 40 turns/min (usually 50 to 150 turns/min), restlessness, and hyperkinesia. Twenty-four spinners and 4-CB nonspinners and age-matched controls were subjected to histopathologic, histofluorescent, histochemical, and electron microscopic studies. The most reliable histopathologic marker for prenatal 4-CB injury to the CNS is the presence of cylindrical CNS peninsulas (CCPs) in the spinal and cranial nerve roots. The CCPs consist of either CNS-type myelinated fibers, unmyelinated fibers, or astroglial bundles in varying proportions, and are enclosed by a basement membrane. The CCPs are also observed in 4-CB nonspinners but in none of 12 controls studied. A selective defect in synaptogenesis induced prenatally by 4-CB is proposed as the primary event pursuant to the development of the CCPs, while interference with synaptogenesis may have occurred selectively in the striatonigral dopaminergic system. This is suggested by electron microscopy on the nucleus accumbens and also by the responses to administration of dopaminergic agonists and antagonist. The 4-CB induced clinico-pathologic anomaly may serve as a singular model for understanding human neurologic disorders, in particular, Werdnig-Hoffmann disease and minimal brain dysfunction syndrome.

Animals↗
PubMed1979

Facial myokymia. Pathological features.

Pathologic examination in a case of facial myokymia showed edema and mild astroglial proliferation of the ipsilateral seventh nerve nucleus; gliomatous tumor involvement occurred rostral to this nucleus. These findings give circumstantial support to functional deafferentation as the cause of facial myokymia.

Adult↗
PubMed1978

Werdnig-Hoffmann disease: proposal of a pathogenetic mechanism.

Light and electron microscopic study and morphometric analysis were performed on the spinal cords and roots from six cases of acute Werdnig-Hoffmann disease and four control cases, in search of the pathogenesis of the selective motor neuron changes considered primarily responsible for Werdnig-Hoffman disease. This investigation posits a centrifugal traction mechanism based upon the discovery of cylindrical outgrowths of glial bundles, selective loss of large myelinated fibers, and axonal degeneration in the proximal portion of anterior spinal roots (and to a lesser extent in posterior spinal roots) in all six disease cases. This traction mechanism exerts principally upon anterior spinal nerve roots and can account for morphologic and morphometric data characteristically ascribed to Werdnig-Hoffmann disease.

Axons↗
PubMed1978

Effect of denervation on coxsackie A virus myositis in mice: an electronmicroscopic study.

Myositis induced by Coxsackie A4 and A9 viruses was investigated in the gastrocnemius muscles of suckling mice and adult mice with denervation. Denervation markedly increased the susceptibility of adult mice to Coxsackie A virus infection, and this effect was initiated as early as 1 day after denervation. Light microscopy demonstrated inflammation and necrosis in the denervated gastrocnemius muscle of adult mice, whereas muscle from the contralateral leg showed only infrequent, mild, focal myositis. Ultrastructually, crystalline arrays of virus particles were seen in the infected muscle fibers and in the phagocytes of both suckling and adult mice. Nuclear alterations, especially in the myotubes, and a characteristic compound membrane-vesicle complex (CMVC) in the sarcoplasm, developed simultaneously. Replicating and fusing myoblasts, activated as part of the regenerative process after denervation, appeared to be closely associated with the susceptibility of muscle to Coxsackie A virus infection.

Animals↗