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Biomedical subjects

R Marks

Publications and source records attributed to R Marks.

At least 415 records · Page 23Linked to original sources
PubMed1981

Changes in suspensions of human keratinocytes due to trypsin.

Epidermal cell suspensions derived from keratotomed samples of normal human skin have been studied by light microscopy and by scanning and transmission electron microscope techniques. The method allows detailed inspection of the keratinocyte membranes. However, the trypsin used to obtain the suspensions limits the usefulness of the technique as some of the features observed - including invagination of desmosomes, vacuolation, and redistribution of tonofibrils - may be attributable to this proteolytic enzyme.

Epidermal Cells↗
PubMed1981

Comparison of xeroradiographic and ultrasound detection of corticosteroid induced dermal thinning.

A pulsed ultrasound technique was shown to have a high degree of correlation with the established xeroradiographic method for the determination of dermal thickness both in normal skin and corticosteroid treated skin, although xeroradiography consistently gave a higher value than ultrasound. Using the pulsed ultrasound technique, an early onset of dermal thinning could be detected 2 days following treatment with creams containing 0.05% clobetasol propionate and 0.1% beta-methasone 17-valerate. The amount of dermal thinning produced by the clobetasol propionate preparation was significantly greater than that produced by cream base, clobetasone butyrate 0.05% cream and hydrocortisone 1% cream as determined by both techniques. The pulsed ultrasound technique is an accurate, noninvasive and safe method for determining dermal thickness.

Adrenal Cortex Hormones↗
PubMed1981

Measurement of biological ageing in human epidermis.

Measurements were made of the thickness of the epidermis, the dimensions of keratinocytes and of the surface areas of individual corneocytes in normal human skin from three non-light exposed sites. The numbers of cells in the epidermis and their height decreased with age, whereas the surface area of individual corneocytes tended to increase with increasing age. The changes demonstrated may be responsible for some of the alterations noted clinically in the skin of elderly individuals.

Abdomen↗
PubMed1981

Severe disorders of keratinization: effects of treatment with Tigason (etretinate).

Twenty patients with disabling disorders of keratinization were treated with Tigason (etretinate, Ro 10-9359), an oral aromatic retinoid, and the clinical responses and the effects on the skin were monitored. Most patients showed a considerable clinical improvement within 4 weeks. Side effects, such as cheilitis, were common but mostly transient or minor. In the skin there was a decrease in glucose-6-phosphate dehydrogenase activity within the granular cell layer of the epidermis, and an increase in mean epidermal thickness and mean corneocyte area. However, there was little apparent effect on epidermal proliferation or on histological and ultrastructural appearances. These findings suggest that the drug acts at a late stage of epidermal differentiation.

Drug Administration Schedule↗
PubMed1981

Skin reactions to carbamazepine.

Three patients with a generalized eruption caused by carbamazepine are described. Two reactions were eczematous, and one was lichenoid in nature. Oral challenge with the drug reproduced the skin disorder in each of these patients. Immunofluorescence microscopy studies demonstrated that in four out of six subjects taking carbamazepine, there were deposits of immunoglobulins in the skin.

Aged↗
PubMed1980

The abnormal dermis in pyogenic granuloma. Histochemical and ultrastructural observations.

The connective and vascular tissues of pyogenic granulomas have been studied in lesions from forty-six patients. Twenty were studied histochemically, and five were examined ultrastructurally. Both tissues showed a wide range of maturity and cellular activity. The fibroblasts in particular showed evidence of increased synthetic activity. Intranuclear inclusion bodies, suggestive of altered synthetic activity, were found in the endothelial cells of four lesions. It is suggested that pyogenic granuloma arises from disordered growth of papillary dermis.

Connective Tissue↗
PubMed1980

The determination of regional and age variations in the rate of desquamation: a comparison of four techniques.

The measurement of the rate of desquamation is an important parameter for epidermal cell kinetic considerations. In order to obtain such information, we have compared 2 existing techniques with a new one and with a modification of a little-used technique for determining the rate of cell loss from the stratum corneum. We have also studied regional and age variations in desquamation in normal skin. The results of the studies performed show there was a strong positive correlation between the "chamber" technique (which measures passive desquamation) and the "scrub" technique (measuring forced desquamation). There was similar strong negative correlation for the scrub technique and the dansyl chloride fluorescence method which measures stratum corneum renewal.

Abdomen↗
PubMed1980

A technique for studying the structural detail of isolated human corneocytes.

A technique for the isolation of human stratum corneum cells from any depth within the horny layer is described. Examination of the cells by light, scanning and transmission electron microscope permits a detailed morphological profile of the plasma membrane to be constructed. It is suggested that the technique will be of particular value in determining the effect of chemical agents on the cellular components of the horny layer.

Cell Membrane↗
PubMed1980

Detection of the action of salicylic acid on the normal stratum corneum.

The undoubted clinical usefulness of salicylic acid contrasts markedly with its barely detectable action on normal skin. In this study we have attempted to extend our understanding of the action of salicylic acid by monitoring its effect on the stratum corneum using newly developed techniques for assessing desquamation, as well as using conventional methods for measuring other aspects of epidermal activity. Our findings have succeeded in demonstrating that salicylic acid enhances the shedding of corneocytes and we suggest that this compound in some way decreases corneocyte to corneocyte cohesion. We have confirmed that salicylic acid has no effect on the mitotic activity of the normal epidermis.

Cell Count↗