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Biomedical subjects

Y Sasai

Publications and source records attributed to Y Sasai.

At least 145 records · Page 8Linked to original sources
PubMed1986

Immunohistochemical study of S-100 protein and neuron specific enolase (NSE) in melanocytes and the related tumors.

Normal human skin, malignant melanoma, nevocellular nevus, blue nevus, nevus of Ota and mongolian spot were immunohistochemically investigated on the localization of S-100 protein and neuron specific enolase (NSE). Tissues were fixed with buffered-formalin, processed with routine procedure and examined by the ABC technique. All cases of malignant melanoma and nevocellular nevus showed a relatively high amount of S-100 protein, but NSE was scantly demonstrated on about the half cases of these tumors. Blue nevus, nevus of Ota and mongolian spot revealed the presence of a small amount of S-100 protein and NSE on the half cases. Normal melanocytes were devoid of S-100 protein and NSE. Our results suggest that S-100 protein is the useful marker for diagnosis of malignant melanoma, and immunoreactive intensity for S-100 protein represents the differentiation of neural crest derived melanogenic cells and tumors.

Histocytochemistry↗
PubMed1985

Cytofluorometric study of thiol and disulphide groups in guinea pig epidermis.

Content of thiol and disulphide groups was cytofluorometrically measured on guinea pig keratinocytes, which were separated into three fractions. Free keratinocytes were obtained by the treatment of EDTA and trypsin. After the treatment keratinocytes were separated into three fractions by centrifugation on a continuous colloidal silica (Percoll) density gradient. Cells in each fraction were stained with N-(7-dimethylamino-4-methyl-3-coumarinyl)maleimide, and measured by cytofluorometry. Thiol concentration was low in basal cells, and higher in both spinous and granular cells. Disulphide group content was low and fairly constant in them. Human peripheral lymphocytes and guinea pig spleen lymphocytes were used to examine the influence of EDTA-trypsin treatment. No remarkable loss of either thiol or disulphide groups was found in them after the treatment.

Animals↗
PubMed1985

Studies on collagen in the experimental myocardial infarction.

The healing process of myocardial infarction was studied with special reference to the production of collagen by the determinations of prolylhydroxylase (PHase) activity and contents of hydroxyproline (Hyp) of the collagen subfractions, i.e., neutral salt soluble (NSC), acid soluble (ASC) and insoluble collagens (ISC) in comparison with histologic observation of the proliferation of connective tissue in the canine heart. The contents of Hyp in NSC and ASC increased in the infarcted tissue 5 days after coronary ligation prior to its increase in ISC. The content of Hyp in NSC, which is a precursor of ASC and ISC, reached the maximal value at 7 days and that reached the maximal value in ASC 7 to 14 days after coronary ligation. ISC increased markedly after 14 days. PHase activity increased on the second day and attained to the highest at 5 to 7 days. Proliferation of fibroblasts paralleled with the increases in PHase activity and NSC, and an increase in collagen fiber did with the contents of ISC. From these results it is concluded that in the healing stage of myocardial infarction, PHase was activated earlier than the increase in immature collagen in the infarcted area which was observed 5 to 7 days after coronary ligation and was followed by the production of mature collagen after 14 days.

Animals↗
PubMed1984

Enzymatic dehydrogenation of tryptophan residues of human globins by tryptophan side chain oxidase II.

Enzymatic dehydrogenation of tryptophan residues in human alpha- and beta-globins has been demonstrated with tryptophan side chain oxidase II, a hemoprotein from Pseudomonas. In 1 M ammonium acetate, pH 4, the enzyme catalyzed the conversion of Trp-14 of alpha-globin to alpha, beta-dehydro-Trp. Under identical conditions, Trp-15 of beta-globin was converted to alpha, beta-dehydro-Trp, whereas Trp-37 was unmodified. No modification was obtained in 0.4% sodium dodecyl sulfate or 8 M urea. The dehydrogenase component of tryptophan side chain oxidase II was also active toward globins in the presence of ferricyanide, whereas tryptophan side chain oxidase I was inert. Upon analyses of the tryptic fragments of the modified beta-globin, two forms of alpha, beta-dehydro-Trp-15 distinguishable by ultraviolet absorption and fluorescence were identified. Each of them rapidly equilibrated with another form on irradiation at 300-380 nm. We tentatively assigned them to two isomers of alpha, beta-dehydro-Trp distinguishable by the configuration around its beta-carbon atom. alpha, beta-Dehydro-Trp in globins and certain polypeptides used herein showed a blue fluorescence at 420 nm. In [alpha, beta-dehydro-Trp 15]beta-globin, the fluorescence was exceptionally intense, the fluorescence yield being comparable to that of NADH. From several lines of evidence, the result was ascribed to the excitation energy transfer from Trp-37 to alpha, beta-dehydro-Trp-15 in the modified beta-globin.

Globins↗
PubMed1984

Immunohistological demonstration of S-100 protein in the cutaneous nervous system.

S-100 protein, isolated from mammalian brain, has widely been used for immunohistochemical marker of the glia cells and the cells derived from the neural crest. In the present study, we made anti S-100 protein antibody and studied the immunoreactive distribution of S-100 protein in the cutaneous nervous system. Albino rabbits were immunized with S-100 protein and complete Freund adjuvant, and antiserum was purified by ion-exchange chromatography. Formalin-fixed normal human skin and sciatic nerve of rat were examined by the PAP method. S-100 protein was detected in Schwann cells of sciatic nerve of rat and cutaneous nerve bundles of human skin specimens. Meissner corpuscles and inner core cells of Pacinian corpuscles of human skin were S-100 protein positive. These findings suggest that the staining of S-100 protein with PAP method is a simple and reliable method to demonstrate the cutaneous nervous system. Also, lamellar cells of Meissner corpuscles and inner core cells of Pacinian corpuscles are indicated to be Schwann cell origin.

Animals↗
PubMed1984

Separation of keratinocytes by density gradient centrifugation for DNA cytofluorometry.

A method for the separation of guinea pig epidermal keratinocytes, in which the Feulgen-stainable material suffers minimal damage, has been investigated. The principal stage involves trypsin treatment of the epidermal sheet, stripped from the dermis with ethylenediamine tetraacetic acid. The epidermal cells thus isolated are separated into three groups by centrifugation on a continuous colloidal silica (Percoll) density gradient. The resulting arrangement of the keratinocytes in the centrifuge tube corresponds to their arrangement in situ, with basal cells at the bottom and the more differentiated cells above. By morphological examination, it can be shown that relatively pure fractions of basal cells, spinous cells, and granular cells are obtained by this method. With respect to DNA distribution pattern, there was good agreement between that of keratinocytes separated by the microdissection-ultrasonic irradiation method, or by the chymotrypsin method as reported previously by us, and that obtained by the present method.

Animals↗
PubMed1984

Cytofluorometric study of nuclear DNA in the epidermis of keratotic dermatoses.

The cell cycle duration of basal cells in the epidermis of keratotic dermatoses was investigated with cytofluorometric method. In normal epidermis, the relative time spent in each phase was 85.1% (G1), 13.1% (S) and 1.8% (G2 + M). The relative time in ichthyosis vulgaris epidermis was similar to that in normal epidermis. In the case of psoriasis and non-bullous congenital ichthyosiform erythroderma, the relative number of S phase cells was more than that in normal epidermis. In psoriatic epidermis, nuclear protein value was highest not only in G1 fraction of basal cells but in differentiating cells.

Adolescent↗