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Biomedical subjects

H Nagara

Publications and source records attributed to H Nagara.

At least 73 records · Page 4Linked to original sources
PubMed1981

Triethyl tin does not induce intramyelinic vacuoles in the cns of the quaking mouse.

Triethyl tin (TET), when injected intraperitoneally, failed to produce the typical intramyelinic edema in the spinal cord of quaking mice with two different genetic backgrounds (B6C3H-qk and BTBRTF/Nev-qk), while control littermates and normal C57BL/6J mice were susceptible, as expected. The only prominent change in the quaking mice was the presence of spherical vacuoles containing floccular electron-dense materials, some of which were clearly within the oligodendroglial perikarya and the inner and outer tongues. They are likely to represent degenerative responses. Consistent with the lack of edema, no increase in the water content was found in the quaking spinal cord following TET injection. Although the presence of numerous interlamellar tight junctions in quaking CNS myelin may mechanically restrict formation of the intralamellar vacuoles, the unique changes in the oligodendroglia and the lack of edema fluid accumulation suggest more fundamental metabolic abnormality that renders the quaking CNS resistant to the triethyl tin-induced edema.

Animals↗
PubMed1981

Resistance of quaking mouse CNS to triethyl tin edema.

Intraperitoneal injection of triethyl tin (TET) sulfate, 5 or 10 mg/kg body weight did not induce intramyelinic edema without altering water content in quaking mice while in C57BL/6J and littermate control mice, water content was increased and typical intramyelinic edema was induced following TET injection. Even among control mice, however, there were some strain differences in the histological severity of the edema, which were in precise agreement with the quantitative alterations in water content. These observations suggest that CNS myelin in quaking may differ qualitatively from that in controls and the mode of response to TET is under genetic control.

Animals↗
PubMed1981

Brindled mottled mouse: morphological changes of brain and visceral organs in hemizygous males following copper supplementation.

Intraperitoneal injections of cupric chloride prevent neuronal degeneration in the hemizygous brindled mottle mouse, MO br/Y, a murine model of kinky hair syndrome (KHS) in humans. At 6-9 months after two i.p. injections, the brain of MO br/Y revealed slightly increased amounts of lipofuscin pigments in the cerebral cortical neurons, cytoplasmic inclusions in the thalamic neurons, and axonal spheroid formation in the tuber cinereum, cerebellum and brain stem. Increased numbers of mitoses, bizarre hyperchromatic giant nuclei, and numerous clear vacuoles were frequently seen in the proximal renal tubular epithelium. Numerous myelin figures were conspicuous features in these epithelial cells at ultrastructural level. Such changes were not found in the littermate controls but in the heterozygous brindled mottled mouse, MO br/ +, identical changes were noted in equal or even higher frequency. These observations suggest that cupric chloride injections effectively modify the expression of the genetic defect in MO br/ Y.

Animals↗
PubMed1981

The effect of copper supplementation on the brindled mouse: a clinico-pathological study.

Brindled mottled is a neurological mutant mouse. Hemizygous males have many clinical and biochemical features in common with kinky hair syndrome (KHS) in humans, and usually die around postnatal day 15, after severe emaciation. Neuronal mitochondrial abnormalities and neuronal degeneration in the cerebrum and cerebellum were constant neuropathological findings in this mutant. A single intraperitoneal injection of cupric chloride, 10 micrograms/g body weight, resulted in an improvement of clinical symptoms and prevention of neuronal degeneration. The degree of improvement was dependent on the date of injection, and day 7 to 10 postnatal appeared to the most effective date. The male hemizygotes which received cupric chloride injections at day 7 or 10 overcame the lethality, and no neuronal degeneration was detected in these mice, although neuronal mitochondrial changes were still persistent. However, following two injections at days 7 and 10, no abnormalities were detected in the cerebral cortical neurons. Even at the ultrastructural level, abnormal mitochondria were very scarce. In the cerebellum, however, mitochondrial changes in the Purkinje cells, particularly in the rostral portion, and generation of white matter were noted in these mice, which were clinically perfectly healthy, judging from the growth rate and behavior. However, cerebellar changes were far less in those which received additional injections later on. These observations indicate that, at least in brindled mutant mice, supplementation of copper is quite beneficial for clinical improvement and the prevention of neuropathological lesions, but the date of administration appears to have crucial importance.

Animals↗
PubMed1981

Neurogenic muscular atrophy and low density of large myelinated fibres of sural nerve in chorea-acanthocytosis.

In three cases of chorea-acanthocytosis (acanthocytosis and neurological disease, or familial degeneration of the basal ganglia with acanthocytosis), biopsies of short peroneal muscles and sural nerves were studied histologically. The muscles showed groups of atrophic fibres with clumping of sarcolemmal nuclei in all cases. It was concluded that neurogenic muscular atrophy should be included as one of the main pathological findings in chorea-acanthocytosis. The sural nerves showed a small number of large myelinated fibres in two cases. This finding remains to be confirmed in other cases.

Acanthocytes↗
PubMed1981

[The diagnosis of left atrial thrombi by selective coronary arteriogram and two-dimensional echocardiogram (author's transl)].

In 14 patients with left atrial thrombi, coronary arteriography and real time, two-dimensional echocardiography were performed and compared with the surgical findings. Age of the patients with left atrial thrombi was relatively high, and their hemodynamic findings were severe. By the combined use of coronary arteriography and real time two-dimensional echocardiography, the prediction of left atrial thrombi was possible in 93%. Coronary arteriography provided a useful information as to the location of thrombi, especially in the left atrial appendage, while the size and shape of thrombi were not predictable by this method. On the contrary, two-dimensional echocardiography was useful to determine the size and shape of the thrombi.

Adult↗
PubMed1980

An ultrastructural study on the cerebellum of the brindled mouse.

Chronological morphological alterations of the cerebellum, with particular attention to the Purkinje cells, were investigated in the brindled mottled MObr mouse, a neurological mutant mouse with close clinical similarity to Kinky hair syndrome (KHS) in humans. Seven days post-natally, slight irregularity in the morphology of mitochondria of the Purkinje cell perikarya was the only significant difference between hemizygous MObr mice and litter mate controls. With advancing age the mitochondrial change became more pronounced gradually in the former, not only in the perikarya but also in the dendrites. However, by day 31 or later the mitochondrial change subsided gradually and by day 91, the mitochondria in the majority of Purkinje cells became indistinguishable from those of littermate controls. Despite the extensive mitochondrial alteration, degeneration and necrosis of Purkinje cells were rather mild. Degeneration of white matter was quite conspicuous in the mutant mouse older than 31 days. These morphological changes of the cerebellum are compared with those of other neurological mutant mice, Nervous and Purkinje cell degeneration, and with KHS in humans.

Age Factors↗
PubMed1979

Pigmentary degeneration of the retina in heredodegenerative neurological diseases.

Frequency of pigmentary degeneration of the retina (PDR) among patients with degenerative and heredodegenerative neurological diseases (HDNDs) was estimated based on the hospital statistics. PDR was detected in 3% of 176 inpatients with HDNDs by careful ophthalmologic examination. On the other hand, out of 30 consecutive cases of PDR seen in our Department of Neurology, 15 patients were associated with some form of HDNDs. Atypical PDR were more frequently associated with HDNDs than typical PDR. Among neurological manifestations in those 15 cases of PDR associated with HDNDs, mental deficiency, hearing disturbance, spasticity, progressive ophthalmoplegia and ataxia were most frequently encountered. Four cases with unusual symptomatology were presented. Clinical analysis of cases of PDR associated with HDNDs in the present series as well as in the relevant literature revealed an extreme variety of clinical manifestations and underlying metabolic disorders, suggesting a possible participation of multiple factors in the pathogenesis of PDR. Importance of careful ophthalmologic examination in HDNDs was stressed from the prognostic point of view.

Adolescent↗
PubMed1979

Rigid spine syndrome.

A patient is described with distinctive clinical features including childhood onset of non-progressive muscle weakness, limitation of flexion of the neck and spine, scoliosis, and joint contracture. Muscle biopsy and electromyography showed findings suggestive of a myopathic disorder. The combination of these distinctive clinical features is termed the rigid spine syndrome. Only six cases have been reported in the literature to date.

Adolescent↗