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Biomedical subjects

R L Cabrini

Publications and source records attributed to R L Cabrini.

At least 109 records · Page 6Linked to original sources
PubMed1976

Sulphydryl and disulphide groups in normal and irradiated epidermis.

The distribution of sulphydryl (SH) and disulphide (SS) groups in normal and irradiated epidermis of newly-born rats was studied by microspectrophotometric quantitation of the Mercury-Orange reaction. In order to obtain information on (1) the total content of both groups within the different strata of the epithelium, and (2) the mean SH and SS concentration, which is an indicator of the density of these groups per unit of tissue. The content of both groups increased in relation to the extent of irradiated area, whereas there was a decrease in the mean concentration. The increase in content of SH and SS would lead to augmented production of keratin substance previously reported in irradiated epithelia, coincidentally with an acanthotic response. The decrease in concentration of SH and SS indicates a destruction of these groups at cellular level, which may be due to membrane alterations. The findings would explain an acceleration of the keratinizing process together with modifications, both in quality and in quantity, in the horny substance.

Animals↗
PubMed1976

Ultrastructural localization of acid phosphatase in normal and X-irradiated epidermis.

Acid phosphatase activity has been studied in normal and X-irradiated rat epidermis. A remarkable reaction increment was found in irradiated epithelium at the granular layer keeping the same pattern of distribution observed in the normal tissue. No reactive lysosomes or keratinosomes were observed in the cytochemical sections, while many keratinosomes but no lysosomes appeared in the electron microscopic preparations of irradiated animals. Irradiated epithelium is discussed as a suitable model to analyze the role of acid phosphatase in the keratinization mechanisms.

Acid Phosphatase↗
PubMed1976

Microspectrophotometric quantitation of nucleic acid and protein in irradiated epidermis.

Nucleic acid and proteins of newborn rat tail subjected to local X-irradiation were microspectrophotometrically studied. Feulgen, gallocyanine chrom-alum and naphthol yellow S methods were performed for demonstration of DNA, total nucleic acid and proteins respectively. The amount of proteins and total nucleic acid increases concomitantly with reactional acanthosis. However, the proteins and nucleic acid decrease as from day 3 post-irradiation. A tentative interpretation of the results would point to a giantization of the epidermic cells not only caused by aqueous imbition but also by an actual increase of the cellular protoplasm.

Animals↗
PubMed1975

A quantitative microspectrophotometric study of the lead precipitation reaction for the histochemical demonstration of acid phosphatase.

The possibility of quantitating microspectrophotometrically the lead precipitation reaction for the histochemical demonstration of acid phosphatase was studied using the following models: sections of rat kidney and human prostate gland, and polyacrylamide films with incorporated prostate gland homogenate. The activity of the polyacrylamide models was previously evaluated by a biochemical method and the specificity of the reaction was controlled with specific inhibitors. Linear relations between cytophotometric reading and enzymatic activity, and between optical densities and different incubation periods, were demonstrated. The results obtained indicate the validity of the microspectrophotometric quantitation for this reaction with direct readings over a wide range of the visible light spectrum.

Acid Phosphatase↗
PubMed1975

Ultrastructure of an odontogenic myxoma.

The ultrastructural findings in a case of odontogenic myxoma are described. The main cell type was characterized by several cytoplasmic processes, intracytoplasmic fibrils, numerous glycogen particles, and salient Golgi complexes. A few mitochondria and a scarce endoplasmic reticulum was noted. The matrix consisted of numerous granules with fibrillar projections, collagen bundles, and smaller fibers. The over-all ultrastructural features of this tumor were similar to those described in the human cardiac myxoma and in Wharton's jelly and could be clearly differentiated from the fine structural characteristics of other connective tissue tumors.

Adult↗
PubMed1975

Ultrastructural response of epidermis to actinomycin D.

The response of the epidermis to the effects of actinomycin D was analyzed at ultrastructural level. Important cellular alterations were found at 40 h post infectionem. The degree of nucleolar segregation varied depending on the epidermal layer assayed. Analogies and departures between the present findings and previous investigations, on a similar model with X-ray irradiation, are discussed.

Animals↗
PubMed1975

Thiamine pyrophosphatase and acid phosphatase. Their ultrastructural localization in rat skin.

The ultrastructural localization of TPPase and AcPase in rat skin was studied. AcPase appeared localized in the lysosomes of the basal layer and in the keratinosomes of spinous, granulous and corneum layers. A diffuse reaction was also present in the granulous cells cytoplasm. Only the keratinosomes in the superficial layer were TPPase positive, specially those of the intercellular spaces of the proximal horny cells. The Golgi apparatus of all skin cells reacted strongly towards TPP. Membranous structures with TPPase and AcPase activity were evident within horny cells and seem to be infolded portions of the cell membrane which keep their enzymatic activity.

Acid Phosphatase↗