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Biomedical subjects

M Seiji

Publications and source records attributed to M Seiji.

At least 55 records · Page 3Linked to original sources
PubMed1980

Immunofluorescence studies on cutaneous amyloidosis with anti-keratin antibody.

Skin specimens obtained from two cases of primary localized cutaneous amyloidosis (PLCA) were subjected to study with an indirect immunofluorescence technique using anti-keratin antibody. Distinct fluorescence was observed in stratum corneum, and in spinous and basal cells of the epidermis and also in amyloid masses located in the upper dermis. These results appear to indicate that keratinous protein is one of the constituents of amyloid masses of cutaneous amyloidosis.

Amyloidosis↗
PubMed1978

Urinary acid glycosaminoglycan in epidermolysis bullosa dystrophica (recessive type).

A biochemical study was carried out on the urine of an 18-year-old woman with epidermolysis bullosa dystrophica recessive type E.b.d.r.). The urinary acid glycosaminoglycans were separated and subjected to quantitative and qualitative analyses by gel filtration and column chromatography. A hyaluronic acid and the 0.5 M NaCl elution fraction were increased characteristically in the acid glycosaminoglycan.

Adolescent↗
PubMed1978

Nature of tyrosinase inactivation in melanosomes.

The decrease in tyrosinase activity following incubation of melanosomes isolated from mouse melanoma with dopa appeared to be related to the degree of in vitro melanization of melanosomes caused by incubation with dopa. The inactivation similarly occurred in the dopa-tyrosinase reaction system containing ascorbic aicd, although in the presence of ascorbic acid the dopa-quinone is immediately converted back to dopa and therefore melanin formation does not take place. The mode of inactivation of tyrosinase in melanosomes appeared to be similar to the reaction inactivation which is known to occur in the reaction of plant plant tyrosinase. Superoxide anion (O-2) and singlet oxygen (1O2) were estimated but undetectable during the dopa-tyrosinase reaction. Thus the inactivation of tyrosinase is not caused by the reaction products or the oxygen radicals.

Animals↗
PubMed1978

Isolation and characterization of a Golgi-rich fraction from the Harding-Passey mouse melanoma.

Golgi-rich fraction was isolated from Harding-Passey mouse melanoma by centrifugation through the discontinuous sucrose density gradient and its properties were compared with those of the same fraction isolated from rat liver. The specific activity of UDP-galactose: N-acetylglucosamine galactosyltransferase was 35 times higher in the melanoma Golgi fraction than in the melanoma homogenate and was a half that in the rat liver Golgi fraction. The specific activities of marker enzymes for other subcellular components such as 5'-nucleotidase, acid phosphatase and glucose-6-phosphatase in the melanoma Golgi fraction were all one-third those in the melanoma homogenate. Electron micrographs of the negatively-stained Golgi fractions of melanoma and liver revealed the presence of a system of tubules, vesicles and plate-like center regions which are known as components of Golgi apparatus. Tyrosinase activity was found to be present in this fraction of mouse melanoma, but its specific activity was lower than that in the rough or smooth surface membrane fraction or in the melanosome fraction.

Animals↗
PubMed1978

A convenient method of establishing permanent lines of xeroderma pigmentosum cells.

Nine lymphoblastoid cell lines were established after transformation by Epstein-Barr virus of peripheral lymphocytes from four xeroderma pigmentosum (XP) patients, the parents of one XP patient, and three normal donors. All these cell lines proliferate as suspension in Roswell Park Memorial Institute Medium 1640 supplemented with 20% fetal bovine serum, without detectable release of infectious Epstein-Barr virus. Some characteristics of these cell lines, such as growth rates, chromosome numbers, UV sensitivities, and activities of unscheduled DNA syntheses induced by UV, 4-nitroquinoline 1-oxide, and N-methyl-N'-nitro-N-nitrosoguanidine, were determined. Results confirm that the properties related to XP are not altered by transformation with Epstein-Barr virus and are the same in degrees of defect as are those of dermal fibroblasts from the respective individuals. These XP and normal lymphoblastoid cell lines should be especially useful for biochemical studies on the mechanism of DNA repair, because they are easy to grow in mass culture.

Autoradiography↗
PubMed1977

Inactivation mechanism of tyrosinase in mouse melanoma.

Tyrosinase [EC 1.14.18.1] isolated from mouse melanoma was inactivated during the dopa-tyrosinase reaction. When ascorbate was added to the reaction system, in which dopa-quinone is immediately converted back to dopa by ascorbate thus preventing the formation of melanin, tyrosinase inactivation similarly occurred. If superoxide anions (O2-) or singlet oxygens (1O2), are generated during the reaction they can attack the enzyme protein to be inactivated. Therefore an estimate was made with scavengers for oxygen radicals and with a liquid scintillation counter but neither was detectable. Thus the inactivation involved is not due to reaction products nor oxygen

Animals↗
PubMed1977

Statistical study on malignant melanoma in Japan (1970-1976).

The authors reported in 1972 a statistical study based on 501 cases of malignant melanoma. As continouous study this review was carried out on 456 cases of melanoma which were reported during six years between 1970 and 1976. These two studies showed quite similar results as follows: (1) Yearly incidnece of malignant melanoma indicated a definite upward trend and the average number of patients was 71.1 per year. (2) Distribution by age showed one peak in the seventh decade. (3) Sex ratio was 1.1: 1. (4) The number of cases per total population in Japan showed great increase in over fifth decades and two peaks in the 7th and 8th decades. (5) Average age of the onset of all melanoma was 51.6 years old, while, that of brain and spinal cord melanoma was 25.4 years old. In the skin melanoma with preexisting pigmented skin lesions, the median age of the onset of primary melanoma on the foot was 38.7 years old and that of originated melanoma except foot was 65.9 years old. (6) Incidence of the melanoma was high in the sole considering the number of melanocytes per unit skin area.

Adolescent↗