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Biomedical subjects

P Mancini

Publications and source records attributed to P Mancini.

At least 91 records · Page 5Linked to original sources
PubMed1977

Nuclear matrix of HeLa S3 cells. Polypeptide composition during adenovirus infection and in phases of the cell cycle.

A subnuclear fraction has been isolated from HeLa S3 nuclei after treatment with high salt buffer, deoxyribonuclease, and dithiothreitol. This fraction retains the approximate size and shape of nuclei and resembles the nuclear matrix recently isolated from rat liver nuclei. Ultrastructural and biochemical analyses indicate that this structure consists of nonmembranous elements as well as some membranous elements. Its chemical composition is 87% protein, 12% phospholipid, 1% DNA, and 0.1% RNA by weight. The protein constituents are resolved in SDS-polyacrylamide slab gels into 30-35 distinguishable bands in the apparent molecular weight range of 14,000 - 200,000 with major peptides at 14,000 - 18,000 and 45,000 - 75,000. Analysis of newly synthesized polypeptides by cylindrical gel electrophoresis reveals another cluster in the 90,000-130,000 molecular weight range. Infection with adenovirus results in an altered polypeptide profile. Additional polypeptides with apparent molecular weights of 21,000, 23,000, and 92,000 become major components by 22 h after infection. Concomitantly, some peptides in the 45,000-75,000 mol wt range become less prominent. In synchronized cells the relative staining capacity of the six bands in the 45,000-75,000 mol wt range changes during the cell cycle. Synthesis of at least some matrix polypeptides occures in all phases of the cell cycle, although there is decreased synthesis in late S/G2. In the absence of protein synthesis after cell division, at least some polypeptides in the 45,000-75,000 mol wt range survive nuclear dispersal and subsequent reformation during mitosis. The possible significance of this subnuclear structure with regard to structure-function relationships within the nucleus during virus replication and during the life cycle of the cell is discussed.

Adenoviridae↗
PubMed1977

Possibilities, limitations, and technique for the study of regional myocardial perfusion in man by Xenon-133.

The theoretical possibilities and the practical limitations of the Xenon-133 (133Xe) method for the study of regional myocardial perfusion in man are discussed. The techniques for data acqusition and processing developed over the past 5 years are described in detail. Illustrative examples of experimental findings are reported. The practical interpretation of the data, at the light of the influence of injection site, initial tracer distribution, constancy of counting geometry, spatial resolution, and Xenon retention in fat, is presented.

Coronary Circulation↗
PubMed1977

Periventricular hypodensity in hydrocephalus: a clinico-radiological and mathematial analysis using computed tomography.

The computed tomography (CT) scans carried out in hydrocephalic patients before and after surgical treatment [cerebrospinal fluid (CSF) shunting] were assessed by analysis of the densities. The numerical data were compared to the pictorial record on the display console. The periventricular hypodensity was correlated to the clinical parameters and to the time lapse after surgical treatment. The subependymal hypodensity shows good direct correlation to the transit of CSF from the ventricles to the white matter, and to the clinical status of the patients. The mathematical analysis supplies objective data and comparable indices. It constitutes the starting point for an automatic evaluation of the CT images of the process of transependymal CSF resorption in non-treated and treated hydrocephalus.

Absorptiometry, Photon↗
PubMed1976

Methods for the study of regional myocardial perfusion in patients with atherosclerotic coronary artery disease: findings at rest after nitroglycerin and during angina pectoris.

In patients with ischemic heart disease the evaluation of regional myocardial perfusion by 133Xenon intracoronary injection using a gamma camera computer system allows the detection of regional alterations of myocardial perfusion. While at rest a minority of the patients studied shows large alterations, during pacing induced angina a severe reduction of regional myocardial perfusion can be evidenced both in initial distribution scintigrams, when the injection is performed during angina, and on the washout curves when angina is induced immediately after the injection, during the course of the washout.

Angina Pectoris↗