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Biomedical subjects

M Koga

Publications and source records attributed to M Koga.

At least 469 records · Page 26Linked to original sources
PubMed1982

Rhabdomyosarcoma of the right ventricle.

A case of a 66-year-old male with rhabdomyosarcoma of the right ventricle who presented first with a pleuritic chest pain and later developed congestive heart failure with A-V block is described. The total period of the disease was about 9 months. At autopsy the right ventricle and wall were found to be replaced by tumor tissue which was diagnosed histologically as rhabdomyosarcoma of the alveolar type. We described one case and 52 rhabdomyosarcomas of the heart from the literature; the ages ranged from 3 months to 92 years with 29 men and 23 women (unknown 1). The primary lesions were right ventricle 29%, right atrium 26%, left atrium 24%, left ventricle 6%, and others 15%.

Aged↗
PubMed1982

Isolation of an extracellular proteinase (keratinase) from Microsporum canis.

Proteolytic activity was demonstrated when a strain of Microsporum canis was cultured in broth with human hair, but not in the medium without hair. The extracellular proteinase (keratinase) was isolated and purified by chromatography. Disc electrophoresis showed one protein band of extracellular proteinase, and the antibody against this enzyme gave a single precipitin line in agar diffusion. The IgG fraction completely neutralized the proteinase activity. The proteinase of M. canis may play a role in infection caused by this fungus, by affecting keratinized tissue such as stratum corneum and hair.

Chromatography, Gel↗
PubMed1981

JHM infections in rats as a model for acute and subacute demyelinating disease.

An animal model with different central nervous system (CNS) disease processes associated with demyelination is described which provides a basis to analyse the pathogenetic mechanisms leading to these disorders. Intracerebral infection of rats with the murine coronavirus strain JHM can result in an acute encephalomyelitis with a short incubation period or in subacute to chronic encephalomyelitis occurring after prolonged incubation. The most prominent finding of the latter two diseases consists of typical demyelinated lesions distributed in selected areas of the CNS. The induction of high rates of animals with demyelination depends both on properties of the virus used for infection and host factors such as age and immune status. A high number of rats with demyelination was obtained by intracerebral inoculation of temperature sensitive mutants into suckling rats with maternal JHM antibodies.

Animals↗
PubMed1981

Choledochal cyst.

The computed tomographic (CT) appearance of a choledochal cyst is reported. Although the appearance on the precontrast scan was highly suggestive of this diagnosis, the definitive was made on CT following the intravenous administration of a biliary contrast agent.

Adolescent↗
PubMed1981

Genetic variation of neurotropic and non-neurotropic murine coronaviruses.

The murine coronavirus strains MHV JMH, MHV 1, MHV 2, MHV 3 and MHV A 59 were tested for their neurovirulence in weanling rats. The strain JHM was found to be highly neurovirulent for weanling rats, whereas the other strains were not, or only slightly, neurovirulent. MHV 1 caused no lesions in weanling rats. The other strains (MHV 2, MHV 3 and MVH A59) induced predominantly subclinical infections in weanling rats as demonstrated by an increase of antibodies and inflammatory lesions in the liver. Analysis of these strains by cross-neutralization revealed variable degrees of antigenic relationship between these viruses which were not related to their neurovirulence. However, when these strains were compared by analysing the T1-RNase-resistant oligonucleotides of virion RNA, the highly neurovirulent strain JHM was found to differ significantly in its nucleotide sequence from the other less-neurovirulent strains.

Animals↗
PubMed1981

Experimental transmission of Creutzfeldt-Jakob disease.

Tissues taken from 10 patients with Creutzfeldt-Jakob disease (CJD) were inoculated to many species of small rodents and primates. Successful transmission was done from 9 patients with a varied incidence after different incubation periods. After the second passage, the incidence became high and incubation periods were reduced approximately to four months in mice. Squirrel monkeys needed the longest incubation period in our experiments. Intracerebral inoculation was the fastest route of transmission followed by other parenteral and oral routes. Spongiform change and gliosis in the CNS were common pathological changes, though their distribution was peculiar to each animal species. The distribution in mice differed with each inoculated material taken from the patients, suggesting the multiplicity of CJD agents. Unconventional properties of the causative agent disclosed through this animal model were discussed.

Administration, Oral↗