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Biomedical subjects

M Manabe

Publications and source records attributed to M Manabe.

At least 109 records · Page 6Linked to original sources

Production of blister in normal human skin in vitro by blister fluids from epidermolysis bullosa.

Pathogenic mechanisms involved in the blister formation of epidermolysis bullosa (EB) are not clearly understood at present. In this paper, we attempted to produce experimental blistering in vitro similar to the histologic picture of EB simplex (EBS) and recessive dystrophic EB (RDEB). It was demonstrated by light and electron microscopy that the medium containing fresh blister fluids from the patients with EBS or RDEB could produce similar histologic features in normal human skin (in vitro) to those of the skin lesions of patients (in vivo). This observation may open new avenues of approach to studying these diseases.

Blister

Comparative studies of the marginal band and plasma membrane of the epidermis.

The membranous fraction isolated from stratum corneum by 8M urea-beta ME containing alkaline buffer (pH 9.0) is quite crude when observed by electron microscopy. However, this procedure may be useful for clinical samples, as one can isolate and compare both the soluble (interfilamentous) fraction and the keratin filament from the same sample in addition to the residues (membranous fraction). A further purified membranous fraction was isolated by a new method. Human stratum corneum was chopped and treated with 8M urea-50 mM Tris-HCl (pH 9.0), digested by the use of trypsin, and the product fractionated by a sucrose density gradient to obtain separate single cells without the cytoplasm. One sample was then treated with trypsin for 1 hour and another with urea buffer for 24 hours. Observations revealed a thickened inner membrane (marginal band) of approximately 150A. Each of the membranous samples contained a level of half-cystine markedly higher in amount (around 100/1,000) and involved mostly in the epsilon-(gamma-glutamyl) lysine cross-linkages (around 30%). In order to compare the membranous fraction of horny and living cells (marginal bands and plasma membranes), the fraction was then isolated from living cells. The relative amino acid composition of the membranous fraction of the plasma membrane resembled that of human erythrocytes, but was quite different from that of the marginal band. These comparative studies of biochemical and morphological features suggested the importance of S-S cross-linking enzymes and transglutaminase in the transformation mechanism of the marginal band.

Amino Acids

Foetomaternal relationships of serum bile acid pattern estimated by high-pressure liquid chromatography.

The bile acid patterns in the maternal and umbilical vein and artery serum samples were analysed by a two-step chromatographic method involving group separation by piperidinohydroxypropyl-Sephadex LH-20 and high-pressure liquid chromatography using immobilized 3 alpha-hydroxy steroid dehydrogenase. Glycochenodeoxycholate predominates in the maternal blood and taurochenodeoxycholate in the umbilical blood. In cases where a free bile acid was detected in the maternal blood, the same bile acid was also demonstrated in the corresponding cord blood. The concentrations of taurocholate and taurochenodeoxycholate were found to be significantly higher in the umbilical artery than in the corresponding umbilical vein. Our data suggest that there is a bidirectional placental transfer of free bile acids and that there is a transfer of taurine-conjugated primary bile acids from the foetus to the mother.

Bile Acids and Salts

Isolation and characterization of horny cell membrane.

The cornified cell membrane and thickened marginal band were obtained from human stratum corneum by a new, faster procedure involving extraction, tripsinization, and density gradient centrifugation. Observations revealed a fine membranous structure with a thickened inner surface of approximately 150 A (marginal band). Each of the membranous samples contained a level of half-cystines markedly higher in amount than that of earlier findings by Matotsy and Matotsy [5]. The samples also contained high amounts of glutamic acid and lysine residues many of which constitute the epsilon-(gamma-glutamyl) lysine cross-linkages of the cell membrane. This study presents the simple isolation procedure and its results highlight the high content of half-cystines in the basic membrane fraction. In addition, the study reveals the importance of S-S cross-linkages during the formation of the cell membrane.

Cell Membrane