Biomedical subjects

M T Perra

Publications and source records attributed to M T Perra.

29 records · Page 2Linked to original sources

PubMed1985

Morphological and histochemical study of the submandibular gland in Praomys (Mastomys) natalensis.

The submandibular gland in female and male Praomys (Mastomys) natalensis (a South African multimammate rodent) was studied using light microscopy and techniques for the demonstration of carbohydrates. Hematoxylin and eosin stain revealed the presence of a single secreting component that gave a strongly positive PAS reaction. Limiting elements of the granular tubules gave a weakly positive PAS reaction. Acidic glycoproteins were evidenced only in granules of the acinar component.

Animals↗

PubMed1984

Morphological and histochemical studies on the parotid gland of Praomys (Mastomys) natalensis.

The parotid gland of Praomys (Mastomys) natalensis follows the same anatomical pattern of Rodentia since no peculiar morphological and histochemical features were found in the present study that differentiate it from homologous glands in other rodents. It consists of serous secreting components and intralobular ducts that demonstrate no sexual dimorphism. Histochemical studies reveal that the glandular cells of the Praomys' parotid gland contain no acid mucosubstance, but that material of a neutral glycoprotein nature can be found in the secreting cells of acini, epithelium of the ducts, and the ductal lumina.

Animals↗

PubMed1983

Human ceruminous glands: a histochemical study.

Human ceruminous glands were treated for the histochemical demonstration of glycoproteins and of several enzymatic activities. Neutral mucopolysaccharides were detected in the cytoplasm and pigment granules of the epithelial cells, and acid glycoproteins were recognized only in a thin apical zone corresponding to the glycocalyx. Lysosomal enzymes were demonstrated within cytoplasmic granules, while peroxidase, G6PD and 6PGD showed a diffuse reactivity through the entire cytoplasm of the secretory cells. Age and sex-related differences were observed with respect to 17 beta-HSD and the 3 beta-HSD, whose reactivity appeared more intense in the young and in the female than in the old and in the male glands. Finally, all the ceruminous cells showed a strong prostaglandin synthetase reactivity.

Adolescent↗

PubMed1982

Histochemical localization of prostaglandin synthetase in human exocrine glands.

Prostaglandin synthetase activity is histochemically detected in the epithelial cells of the human prostate, seminal vesicle, and deferential ampulla. The addition of the specific inhibitor indomethacin to the incubating medium strongly reduces the staining reaction. The presence of exogenous substrate in the medium is not required for the reaction, since identical results are observed following incubation with and without arachidonic acid. The presence of the enzyme appears to be related to the secretion of prostaglandins into the seminal fluid, but there is a possibility that some prostaglandins influence the metabolism of the secreting cells themselves. The localization of prostaglandin synthetase in the ductal epithelia of human salivary glands is related to a possible regulatory role of the prostaglandins upon the reabsorptive activity of the ductal cells.

Adult↗

PubMed1982

Histochemistry of the 3 beta-hydroxysteroid, 17 beta-hydroxysteroid and 3 alpha-hydroxysteroid dehydrogenases in human salivary glands.

Human parotid and submandibular glands showed no 3 alpha-hydroxysteroid dehydrogenase (3 alpha-HSD) activity. The 3 beta-hydroxysteroid dehydrogenase (3 beta-HSD) and the 17 beta-hydroxysteroid dehydrogenase (17 beta-HSD) appeared intensely reactive in the duct epithelia of the male and female glands and weakly reactive in the acinar cells of the female ones. The failure to demonstrate 3 alpha-HSD activity indicates that in-vivo androgen activation, if present at all, is not so marked as in target organs. The different distribution of the 3 beta-HSD and 17 beta-HSD in the two sexes can be related not only to the oxidation of androgens but also to the metabolism of the female hormones. Glucose-6-phosphate dehydrogenase (G6PD) and 6-phosphogluconate dehydrogenase (6PGD) do not seem to be specifically influenced by the sex hormones as their pattern of distribution showed no sex differences.

17-Hydroxysteroid Dehydrogenases↗

PubMedDate not supplied

Histochemical study of the human bulbourethral (Cowper's) glands.

Human bulbourethral glands were reacted histochemically and immunohistochemically to identify glycoproteins, some androgen metabolic enzymes, and VIP-like immunoreactivity. Neutral/acid mucosubstances were detected in the cytoplasm of the tubuloalveolar and ductal cells. 3 beta-, 17 beta-, and 3 alpha-hydroxysteroid dehydrogenase, G6PD, and 6PGD reactivity were intense in all the glandular epithelium. Small amounts of VIP-positive fibres were observed around the secretory elements.

Adult↗

PubMedDate not supplied

Immunohistochemical study of secretory IgA in the human male reproductive tract.

Male human genital tract was treated for the immunohistochemical demonstration of secretory IgA in order to verify its own possible antimicrobial properties. An intensely positive immunoreaction for sIgA in the epithelial cells of prostate and urethral glands was observed; in the same organs the presence of immunoreactive cell clusters in the subepithelial layers was noted. Immunostaining in the epithelia of deferent duct, seminal vesicle, deferential ampulla, ejaculatory duct and bulbourethral glands was absent. The findings suggest that a local immune response sIgA-mediated is present in the lower male genital tract.

Adult↗

PubMedDate not supplied

Histochemistry of human urethral glands.

Human urethral glands were reacted histochemically and immunohistochemically to identify glycoproteins, some androgen metabolic enzymes, and VIP-like immunoreactivity. Neutral/acid mucosubstances were detected mainly in the apical cytoplasm of the principal cells. 3 beta-, 17 beta-, and 3 alpha-hydroxysteroid dehydrogenase, G6PD, and 6PGD reactivity were intense in all the glandular epithelium. Small amounts of VIP-positive fibers were noted around the secretory elements.

17-Hydroxysteroid Dehydrogenases↗

PubMedDate not supplied

Human urethral epithelium: immunohistochemical demonstration of secretory IgA.

Male human urethral epithelium was treated for the immunohistochemical demonstration of secretory IgA in order to verify its own possible antimicrobial properties. An intense immunoreactivity for sIgA in the entire cytoplasm and at the luminal surface of the apical epithelial cells was observed. The results suggest that sIgA play a prominent role in the local defense mechanisms of the urethra. Such mucosal defense mechanisms may be of significance in the defense of the urinary and genital tract against ascending infections.

Adult↗

PubMedDate not supplied

IgM and IgG in the human male genital tract.

In human seminal plasma it is possible to measure the levels of IgG and IgA, while IgM has been detected in trace amounts in only a few subjects. The source of these antibodies is unknown, although, under certain conditions, they seem to be produced in the sex tissues. Male human genital tract was processed for the immunohistochemical demonstration of IgG and IgM to verify the presence and the source of these antibodies. Only the epithelia of the prostate gland and urethra showed positivity to the immunohistochemical reaction, indicating the presence of IgM-secreting epithelial cells. Clusters of IgM- and IgG-positive immunocompetent cells were also observed in the subepithelial layers of all organs studied. The findings suggest that IgM are present in mucosal surfaces as a result of active secretion, as well as secretory IgA, whereas most of the IgG present in the human seminal plasma are probably derived by transudation process.

Adult↗

PubMedDate not supplied

Prognostic prediction of the immunohistochemical expression of p16 and p53 in cutaneous melanoma: a comparison of two populations from different geographical regions.

p16INK4a and p53 are tumor-suppressor genes frequently altered in various malignancies, including cutaneous melanoma. The purpose of the study was to establish the prognostic value of immunohistochemical expression of p16INK4a a and p53 in sporadic cutaneous melanoma (CM) in two regions with a high-risk for melanoma in Italy and Ecuador. Immunohistochemical staining of p16 and p53 was performed in samples of primary CM from 82 patients with Stage I and II melanoma according to the American Joint Committee on Cancer (AJCC) staging system. Survival differences between categories of p16 or p53 expression were analyzed using the product-limit procedure (Kaplan-Meier method, log-rank test). Clinical variables (gender, age, tumor location, Clark's level, thickness) were correlated with survival and p16 or p53 expression. p16 nuclear immunoreactivity was observed in 85% of Italian patients compared to 48.7% of Ecuadorians; a small number of cases showed p53 immunoreactivity in both populations. Only nuclear p16 expression exhibited a significant correlation with survival (Italians p=0.001, Ecuadorians p=0.017) but did not appear to correlate with any clinicopathological parameter. No significant difference was observed in survival with regard to p53 expression or cytoplasmic p16. Our results demonstrate that nuclear expression of p16 can be considered a molecular prognostic factor in patients with sporadic CM and indicate its importance as a clinical marker.

Adolescent↗