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Biomedical subjects

M Piazza

Publications and source records attributed to M Piazza.

At least 163 records · Page 9Linked to original sources
PubMedDate not supplied

The effect of 3-palmitoyl-(+)-catechin on Kupffer cells in guinea pig liver.

We report a morphometric study on the effect of 3-palmitoyl-(+)-catechin on phagocytic activity of latex particles by Kupffer cells in guinea pig liver. We found an increase in the density of latex particles in Kupffer cells of animals treated with 3-palmitoyl-(+)-catechin. The volume and density of Kupffer cells of treated animals increased (p less than 0.01); there was no significant difference in surface density of the plasma membrane. None of the parameters measured was altered in endothelial cells. These results show that 3-palmitoyl-(+)-catechin produces morphological and functional changes in Kupffer cells.

Animals↗
PubMedDate not supplied

A case of paracoccidioidomycosis: experience with long-term therapy.

We describe long-term therapy for paracoccidioidomycosis occurring in a 61-year-old house-painter from Venezuela. The diagnostic examinations made in South America had shown pulmonary granulomatous lesions and an osteolytic pattern of the left knee that had been considered suspect of malignant disease with an indication for limb amputation. With the aid of fine needle aspiration biopsy (FNAB) and culture examination we diagnosed an osteomyelitis by Paracoccidioides brasiliensis and initiated therapy with itraconazole, 400 mg per day, reduced to 200 mg per day after 2 months. At the end of 2 years of drug therapy, we observed complete regression of the pulmonary lesions and of the osteolytic area of the left knee. Moreover, we have periodically observed our patient to verify his clinical development and he is still in good health. We suggest that this pathology be considered in differential diagnosis of leprosy, tuberculosis, leishmaniasis, and systemic mycoses, even in non-endemic areas.

Antifungal Agents↗
PubMedDate not supplied

The effect of temperature on the ultrastructure of Histoplasma capsulatum during the mycelium-yeast transition.

The ultrastructural morphology of the early phases of mycelium-yeast transition in Histoplasma capsulatum after a temperature shift from 25 degrees C to only 34 degrees C is described. Under this condition of lower temperature oxidative phosphorylation is not completely uncoupled and maximum production of heat shock proteins (hsp) occurs. 24 h after temperature shift more than 90% of the cells still appear vital. Alterations in the organization of the mitochondrial cristae are the only ultrastructural changes observed in these cells. In contrast, 70% of the cells degenerate 24 h after a temperature shift from 25 degrees C to 37 degrees C and in the remaining cells mitochondria are rarely observed. These observations are discussed in relation to the production of hsp, the uncoupling of oxidative phosphorylation and the virulence of different strains of H. capsulatum.

Heat-Shock Proteins↗
PubMedDate not supplied

Porocarcinoma detected by fine needle aspiration biopsy of a node metastasis. A case report.

BACKGROUND: Porocarcinomas were first reported by Pinkus and Meherengan in 1963 as uncommon malignant adnexal tumors of the skin characterized by epidermotropism with pagetoid diffusion within the epidermis. CASE: The cytologic findings of an eccrine porocarcinoma lymph node metastasis in a 65-year-old female and histologic features of the skin recurrence are reported. Metastasis was firstly identified by fine needle aspiration biopsy (FNAB) performed on one inguinal lymph node. Cytologically the tumor was characterized by atypical malignant cells showing clear granular or keratinized cytoplasm and vesicular nuclei, with prominent nucleoli, which were irregularly dispersed or forming nests or cords, sometimes harboring central necrosis. The skin metastasis, detected after the cytologic FNAB diagnosis, showed superficial dissemination within the epidermis and dermal invasion. CONCLUSION: Cytologic diagnosis of porocarcinoma metastases by FNAB is important for adequate treatment, but adherence to strict diagnostic criteria is necessary. The tumor cells could be histogenetically related to the intraepidermal duct cells of the eccrine sweat glands, and pagetoid diffusion is considered a sort of homing phenomenon.

Acrospiroma↗
PubMedDate not supplied

Meningeal melanocytoma: a rare lesion of the central nervous system.

Two cases of meningeal melanocytoma, both localized in the cerebellopontine angle, were studied. The patients underwent surgical excision, and in one case there was a recurrence. All the pathologic criteria of melanocytoma were fulfilled by the 2 reported cases. Immunohistochemical stainings were very important ancillary tools in the differential diagnosis with other pigmented meningeal tumors.

Adult↗
PubMedDate not supplied

Adrenocortical oncocytoma: case report and review of the literature.

Only 9 oncocytic neoplasms of true adrenal origin have been described to date. It therefore seemed of interest to study the histochemical and ultrastructural features of a non-functioning monolateral adrenocortical oncocytoma which was incidentally detected by ultrasonography and magnetic resonance imaging in a 28-year-old woman. The tumor was round, well encapsulated and weighed 73 g. It consisted of islets of eosinophilic cells, and did not display any sign of necrosis. The proliferation rate (as evaluated by mitotic index and percentage of MIB-1 Ki67 positive cells) was low, and atypic mitoses were absent; some rare cells with nuclear atypias were observed and the capsule was focally invaded by oncocytes. Immunocytochemistry did not show expression of vimentin or cytokeratin. The oncocytes had an abundant cytoplasm packed with mitochondria containing plate-like cristae. Smooth endoplasmic reticulum was virtually absent, while rough endoplasmic reticulum cisternae and free ribosomes were abundant. Although the classic histological approach clearly indicates the benign nature of the tumor, the immunocytochemical and ultrastructural features of oncocytes may suggest their potential for malignant behavior.

Adenoma, Oxyphilic↗