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Biomedical subjects

M Oda

Publications and source records attributed to M Oda.

At least 595 records · Page 33Linked to original sources
PubMed1978

A sporadic juvenile case of the amyotrophic lateral sclerosis with neuronal intracytoplasmic inclusions.

In an autopsy case of the sporadic juvenile ALS (a 17-year-old girl) intracytoplasmic inclusions are found in the upper and lower motor neurons and in nerve cells of the dentate nucleus, pontine nucleus, brain stem reticular formation, substantia nigra, thalamus, globus pallidus and others. Histochemically they contain RNA-Protein compounds. Electron microscopically, they consist of randomly interwoven tubules with granular endoplasmic reticulums and free ribosomes in the margin. Each tubule measures 90--150 A in diameter and shows no distinct periodic constiction. Amorphous substances as well as ribosome granules are scattered and associated with those tubules. The inclusion-bearing cells are usually swollen and chromatolytic and have a large hydropic nucleus, suggesting a close relation between the development of the inclusion and chromatolysis. Clinically, a rapid progress of the symptoms (total duration: about 12 months) and conspicuous disturbances of the autonomic nerve, such as sinus tachycardia and bladder sphincter dysfunction, should be noticed.

Adolescent↗
PubMed1978

Taste buds in the vallate papillae of the rat studied with freeze-fracture preparation.

The taste bud of the vallate papillae of the rat has been examined in the electron microscope by using the freeze-fracture technique. Tight junctions as a junctional complex are located at the taste pore, and form a seal between the oral environment and the taste buds. Tight junctions are not only within the taste buds, but also are demonstrated in the granular cell layers of the surrounding lingual epithelium. The present finding suggests that tight junctions of the taste pore link with those of the lingual epithelium. Desmosomes are observed in the buds, but they are smaller in size than in the surrounding lingual epithelium. Besides these junctions, within the buds, gap junctions containing particle-free zones are demonstrated which are called a subcompartment type.

Animals↗
PubMed1978

Different appearance of hepatic collagenase and lysosomal enzymes in recovery of experimental hepatic fibrosis.

1. Both activities of hepatic collagenase and lysosomal enzymes (acid phosphatase, beta-glucuronidase and N-acetyl-beta-D-glucosaminidase) have been observed in the recovery from experimental hepatic fibrosis in rats treated with carbon tetrachloride for 6 to 20 weeks, and compared with the disappearance of newly formed collagen fibers in the recovery process. 2. In the process of experimental hepatic fibrosis, collagenase activity reached maximum on sethe accumulation of collagen fibers in reversible hepatic fibrosis, but decreased to the same level as that of non-treated rat liver in cirrhotic stage. In the reocvery from reversible hepatic fibrosis, collagenase activity reached maximum on second day after the discontinuation of carbon tetrachloride, and decreased to the same extent of that of non-treated rat liver on seventh day. 3. Lysosomal enzyme activity was parallel to the activity of hepatic collagenase and to the accumulation of collagen fibers in the process of hepatic fibrosis. In the recovery stage, lysosomal enzyme activity in mesenchymal cells within the septa increased markedly on second day after the discontinuation of toxic agent but turned to the same level of that of non-treated rat liver seven days later, which was consistent with the appearance and disappearance of collagenase activity. On the other hand the appearance of lysosomal enzymes activities in Kupffer cells and hepatocytes was different from that of collagenase activity. That is lysosomal enzyme activity in Kupffer cells decreased in early days but increased five days later, and the enzyme activity in hepatocytes markedly decreased but gradually recovered to normal level seven days later. 4. The appearance of collagenase was observed at the beginning of the recovery stage. It indicates that mammalian collagenase initiates the collagen degradation and lysosomal enzymes might have a role in the subsequent degradation of collagen.

Animals↗
PubMed1978

Evidence for microfilament involvement in norethandrolone-induced intrahepatic cholestasis.

An experimental study of norethandrolone (NED)-induced intrahepatic cholestasis was made. NED was infused via a portal vein catheter into rat liver in vivo, and measurements were made of bile flow. Liver specimens were taken at intervals for light microscopy and for transmission and scanning electron microscopy. Bile-canalicular-rich membrane fractions were prepared. The effects of NED were also examined in isolated hepatocytes in suspension culture. NED infusion induced total cholestasis by 3 hours. Canalicular alterations commonly associated with cholestasis were found in in vivo infused liver and in isolated hepatocytes. Pericanalicular microfilament changes were also noted in both, with loss of filament structure and replacement by a granular zone. In isolated canalicular membrane fractions prepared from NED-treated animals, the normal investment of pericanalicular filaments was no longer present. Loss of the bile canalicular ruthenium red surface coat was also noted. In view of the identical findings in isolated hepatocytes and in in vivo liver, obstruction and mechanical factors can be excluded as possible causes. The results raise the possibility that the mechanism of NED-induced cholestasis may be related to disaggregation and/or detachment of microfilaments from the canalicular membranes.

Animals↗
PubMed1977

A case of demyelinating encephalomyelitis with some resemblance to collagen disease.

A woman, aged 26 years, who died of progressively worsening demyelinating encephalomyelitis in the course of 4 years is reported. The neuropathological findings included large subcortical softenings in the cerebral hemispheres, tiny perivenous demyelinated foci in their neighborhood and scattered in the white matter. There was an acute vasculitis with fibrinoid exudation in the affected as well as unaffected areas. Focal perivenous mononuclear cell infiltrations are conspicuous in the white matter. The laboratory and postmortem examinations suggested a collagen disease like SLE. The abnormalities included marked increase of serum gamma-globulin, especially of IgG, and elevation of CRP, RA, and ANA titer, moderate thickening of the basement membranes of the renal glomeruli, onion skin-like periarteriolar fibrosis in the spleen, fibrous pericarditis and periadventitial fibrosis of myocardial arteries. Bilateral degeneration of the spinal posterior columns and dorsal roots was also observed. A probable relationship of the modified features in this example of demyelinating encephalomyelitis with abnormal immune mechanisms in the background is discussed.

Adult↗
PubMed1977

Clinical significance of e-antigen/anti-e, with special reference to HBc-antigen in the liver.

e-antigen and anti-e were assayed in sera of asymptomatic HBs-Ag carriers and of patients with liver diseases. Thirteen out of 34 (38.2%) asymptomatic carriers were positive for e-antigen, which was in sharp contrast to the reports from USA and Europe. e-antigen was detected to a greater extent in patients with chronic active hepatitis, reversely anti-e in patients with chronic persistent hepatitis. However, e-antigen was found rarely in patients with cirrhosis and never in 23 cases with hepatoma positive for HBs-Ag. HBc-Ag in the liver was detected in 4 out of 8 e-antigen positive asymptomatic carriers and in 4 out of 5 patients with chronic liver diseases with e-antigen respectively, and moreover in 3 out of 14 anti-e positive cases, so that the presence of anti-e did not necessarily mean the negativity of HBc-Ag in the liver. Anti-HBc titer, however, was lower in anti-e positive sera than in e-antigen positive ones. This may implicate the decreased replication of HBV in cases with anti-e. These results emphasize that the investigation of e-antigen/anti-e is mandatory for the evaluation of the prognosis of asymptomatic carriers and of patients with chronic hepatitis.

Adult↗
PubMed1977

The fine structural localization of adenosine triphosphatase activity on the taste bud in the fungiform papillae of the rat.

The localization of Mg++ activated adenosine triphosphatase (ATPase) activity in rat fungiform taste buds was demonstrated by electron microscopic histochemistry. Reaction product was found on the cell membrane of the taste cells, but not within their cytoplasm. Especially strong reaction occurred in the taste pore. Besides, enzymes were observed in axon-Schwann cell and axon-type I cell interspace, but not in the contacts of the nerve fiber and type II cell. The taste bud could well be distinguished from the surrounding epithelium by the existence of the reaction product. ATPase activity was absent at the synaptic portion where type III cells faced nerve fibers. No reaction product was seen along the basal lamina. In fungiform buds, the nerve fibers were frequently shown to make contact with each other, and these sites were devoid of deposits for ATPase.

Adenosine Triphosphatases↗