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Biomedical subjects

A Zucca

Publications and source records attributed to A Zucca.

7 recordsLinked to original sources
PubMed1999

Subcellular heterogeneity of mitochondrial membrane potential: relationship with organelle distribution and intercellular contacts in normal, hypoxic and apoptotic cells.

The subcellular heterogeneity of mitochondrial membrane potential (mDelta psi) was investigated in confluent and sub-confluent cultures of four cell types (human astrocytes, HEp-2, MDCK and Vero cells) in normal growth conditions, hypoxia and apoptosis. The distribution of high-polarized mitochondria, detected by the potential-sensitive probe JC-1, was found to depend on: (1) the proximity to the cell edge; (2) the local absence of cell-cell contacts; and (3) the local absence of acidic vesicles. Both hypoxia and apoptosis produced a general mDelta psi increase with different redistributions of high-polarized mitochondria. Hypoxic cells maintained high-polarized mitochondria for over 24 hours, until cells underwent necrosis. On the other hand, apoptotic cells showed an unexpected convergence of high-polarized mitochondria into an extremely packed mass at one side of the nucleus, in a stage preceding nuclear condensation, but correlated to the retraction of cell-cell contacts.

Animals↗
PubMed1997

Chromatin pattern by variogram analysis.

Many cytological processes such as cell proliferation, differentiation, transformation, apoptosis, etc., are accompanied by specific chromatin changes, usually identified on the basis of the relative content of euchromatin and heterochromatin. In order to achieve a quantitative, non-subjective evaluation of the chromatin pattern, two different approaches may be undertaken, one consisting in the analysis of the several morphological features of chromatin grains (size, shape, density, arrangement, and distribution), and the second consisting in the analysis of the chromatin globally considered as a coherent texture. Although the second approach appears to be simpler and more suitable, methods of texture analysis--including those specifically designed for the analysis of the chromatin pattern--are rarely applied due mainly to the unsuitability of sampling procedures and the excessive crypticism of results. As an alternative to traditional texture analysis, we suggest a method supported by a sound mathematical theory and approximately 30 years of applications in the field of geostatistics. The method, called variogram, analyzes the intrinsic structure of data sampled at different distance intervals and directions, and outputs easily understandable results. Recently, variogram analysis has successfully been exported from geostatistics to other fields (for example, ecology and epidemiology) that make use of spatially referenced variables. Based on the fact that pixels represent a perfect array of data ordered at regular distance intervals and directions, the variogram can be adopted to explore nuclear images and recognize chromatin patterns. Variograms of different nuclei can be summarized by multivariate methods without the need of previous standardization of data. This allows comparison and discrimination of chromatin patterns from mixed cell populations. Preliminary data obtained from young neurons undergoing massive apoptosis reveal a self-consistent map of nuclear changes correlated to the degenerative process.

Animals↗
PubMed1987

Immunoperoxidase localization of HSV2 antigens in cervical dysplasia and carcinoma.

The AA. have evaluated by means of the immunohistochemical technique the incidence of herpetic phlogosis in 76 women with neoplastic pathologies of the uterine cervix. The patients were submitted to cytologic, colposcopic and histologic examination for CIN. The HSV2 positivity by immunohistochemical method was demonstrated in 53 (35.3%) cases of CIN and invasive carcinoma. The results confirm the frequent association between HSV2 and cervical carcinoma and they support a specific therapeutic approach to be made in the prevention and clinical management of the carcinoma.

Adult↗
PubMed1979

[Automatic determination of triglyceride, cholesterol, glucose and serum uric acid in the screening for preventive medicine (author's transl)].

A centrifuge speed analyzer, used for triglyceride, cholesterol, glucose and serum uric acid determinations, was tested as to linearity, precision, steadiness and accuracy requirements. The results were compared to those obtained by other techniques. Automatic techniques were proved to comply with reliability and practicability requirements, necessary during the screenings for preventive medicine. The centrifuge speed analyzer seems to be particularly fit for the primary prevention trials of coronary heart disease, since the follow-up studies require repeated laboratory examinations.

Adult↗