PubMed HealthSearch

Biomedical subjects

M Manabe

Publications and source records attributed to M Manabe.

At least 127 records · Page 7Linked to original sources

Origin and properties of the blister formation factor in blister fluids from recessive dystrophic epidermolysis bullosa.

The origin and properties of the blister formation factor in recessive dystrophic epidermolysis bullosa (RDEB) blister fluids were investigated. Organ cultures of normal human skin incubated with RDEB dermis extract or with RDEB fibroblast culture medium (FCM) produced a clear subepidermal blister with histology similar to that of a RDEB blister in vivo. The injection of RDEB dermis extract into guinea-pig skin also induced dermal-epidermal separation with similar histology to the skin lesions of RDEB patients. The blister forming activity of RDEB FCM which induces the subepidermal blister was inactivated by heat (60 degrees C for 30 min), trypsin digestion and by treating with EDTA, EGTA, alpha 2-macroglobulin, diisopropyl fluorophosphate and N-ethylmaleimide, but was not affected by dialysis. These results suggest that the RDEB fibroblast produces a blister formation factor(s), and that blister formation may be caused by a combination of a metallo-protease, serine protease and SH protease.

Animals

Ichthyosis linearis circumflexa: morphological and biochemical studies.

Extensive morphological and biochemical studies were carried out on two sibling cases of ichthyosis linearis circumflexa. The condition was found to be similar to psoriasis in the following ways: effectiveness of PUVA therapy, psoriatic changes on light and electron microscopy, high urinary polyamine levels, elevation of several enzyme activities in the scales, and a remarkable change in keratin molecules. These results may reflect an increased epidermal proliferation with a reduced epidermal transit time, as occurs in psoriasis.

Adolescent

Macromelanosomes in X-linked ocular albinism (XLOA).

A case of X-linked ocular albinism is reported. Characteristic Masson-Fontana positive and Dopa positive giant melanin granules were found in keratinocytes, melanocytes and upper dermis. Ultrastructurally the macromelanosome was composed of a dense core and a less dense surrounding mantle.

Adult

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