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Biomedical subjects

M Seiji

Publications and source records attributed to M Seiji.

At least 73 records · Page 4Linked to original sources
PubMed1976

Transfer mechanism of melanosomes in epidermal cell culture.

The mode of melanosome transfer from melanocytes to keratinocytes in epidermal cell cultures has been examined with time-lapse cinematography and electron microscopy. A tip of a melanocyte dendrite containing melanosomes became enfolded by a recipient keratinocyte. It was then pinched off to form a cluster of melanosomes which initially seemed to be surrounded by two layers of membranes. The phagocytized dendrite was gradually decomposed and became an aggregate of melanosomes surrounded by a single membrane of the keratinocyte. The individual melanosomes were dispersed from the aggregate into the keratinocyte cytoplasm, depending on the size of melanosomes. The larger ones were single and smaller ones were complex. The mechanism of melanosome transfer in vitro is a type of cytophagocytosis. The entire process consists of two steps: the first is a cytophagic process and the second a melanosome dispersion process. The process is influenced by various exogenous factors.

Cells, Cultured↗
PubMed1976

Enzyme defects in xeroderma pigmentosum.

Fibroblast strains were obtained from 12 patients with xeroderma pigmentosum of various clinical types. Repair replication of UV-damaged DNA in the fibroblasts was studied by 3H-thymidine labeling and radioautography. DNA repair replication was found decreased in all xeroderma pigmentosum fibroblasts compared with control cells obtained from normal donors. Repair activities in patients cells ranged from nearly 0% in three infant cases and two cases of De Sanctis-Cacchione syndrome to approximately 100% in an adult moderate case. There was, however, no correlation between the level of repair replication and the severity of clinical symptoms. Since three cases which showed a lack of repair DNA replication were infants, it is assumed that these cases may develop De Sanctis-Cacchione syndrome in the future. A genetic analysis of xeroderma pigmentosum cells, was performed with cell fusion methods using irradiated HVJ virus in order to determine the type of the complementation group. XP-1, XP-3, XP-4, XP-6 and XP-9 may be classified into group D; XP-2, XP-7, XP-8, XP-11 and XP-12 into group A; and XP-5 into the group E.

Adolescent↗
PubMed1976

Acrodermatitis enteropathica-like eruption association with parenteral nutrition.

This is a case report of a patient with acrodermatitis enteropathica-like eruption that occurred during parenteral nutrition. The skin lesions were similar to those of acrodermatitis enteropathica, but there were no other major symptoms such as diarrhea and alopecia. It was noticed that the lack of linoleic acid in the diet might be the cause of lesions.

Acrodermatitis↗
PubMed1975

Defective DNA repair replication in xeroderma pigmentosum fibroblasts and DNA repair of somatic cell hybrids after UV irradiation.

Primary fibroblast cultures were obtained from 9 patients with xeroderma pigmentosum of various clinical types. Repair replication of the UV-damaged DNA in fibroblasts was studied by means of 3H-thymidine labeling and radioautography. A DNA repair replication was found to be decreased in all xeroderma pigmentosum fibroblasts as compared with the control cells obtained from normal donors. The repair activities in cells from patients ranged from nearly 0% in two infant cases and one case of De Sanctis-Cacchione syndrome to approximately 100% in adult moderate case. There was, however, no correlation between the level of repair replication and the severity of clinical symptoms. Since two cases which showed a lack of repair DNA replication were infant, it is assumed that these cases may develop De Sanctis-Cacchione syndrome in future. On xeroderma pigmentosum cells, a genetic analysis was performed with cell fusion methods using irradiated HVJ virus in order to determine the type of the complementation group. XP-1, XP-4 and XP-9 may be classified into the group D; XP-2, XP-7 and XP-8 into the group A; and XP-5 into the group E.

Adolescent↗