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Biomedical subjects

M Governa

Publications and source records attributed to M Governa.

At least 55 records · Page 3Linked to original sources
PubMed1982

Effect of lead on physical state of erythrocytes and model membranes.

Lead has an high affinity for erythrocyte and influences the membrane bound enzymes activities but its interactions with biological membranes is still unclear. We have investigated the effect of lead as free ion on physical state of erythrocytes and liposomes by Electron Spin Resonance (ESR) using two spin labels 5-doxyl-stearate (5-NS) and 16-doxyl-stearate (16-NS) and by DPH (1,6-diphenyl-1,3,5-hexatriene) fluorescence polarization analysis. Lead induces decrease of fluidity in natural membrane which is more evident in membrane hydrophobic core; the effect is not correlated with lead concentration. Lead ion interacts with negative charged liposomes inducing an increase of their microviscosity.

Cardiolipins↗
PubMed1982

Changes of membrane fluidity in erythrocytes of lead-exposed workers.

We have studied the effect of lead on the fluidity of erythrocyte membrane to clarify if lead can interact in vivo with biological membranes. Erythrocyte membranes were chosen in our study because a decrease of red cell osmotic fragility is also evident in the absence of laboratory and clinical signs of anaemia. The study was undertaken using the Electron Spin Resonance technique with two spin labels 5-doxyl stearate and 16-doxyl-stearate, which probe the physical state of the polar surface and the inner core of the membrane respectively. Red blood cells and erythrocyte ghosts were prepared from the blood of workers occupationally exposed to lead and from healthy controls. The determinations of Pb blood, Pb urine, urine coproporphyrin and delta-aminolevulinic acid showed an increased internal dose of lead, but the ordinary metabolic and haematological parameters were in the normal range. Our results show that in lead workers there is a change in chemical physical state both in erythrocytes and erythrocyte ghosts consistent with a decrease of membrane fluidity, which is evident in the surface as well as in the inner core of the membrane. The degree of membrane fluidity modification does not appear correlated with blood lead level. Changes in the membrane structural organization could be the molecular basis of some pathological alterations induced by lead.

Adult↗
PubMed1982

[Adsorption of proteins by artificial mineral fibers: in vitro experiments].

Since previous studies reported that in vitro some proteins and phospholipids were absorbed by asbestos fibres, namely chrysotile, in this study, man made filamentous glass fibers are been tested in vitro at the presence of proteins. The objective was to obtain evidence to evaluate whether continuous glass fibers have a behaviour similar to asbestos fibres. A sample of chrysotile fibres was used as control. Uptake of bovine serum albumin and horse spleen ferritin on these continuous glass fibres has been observed. However on glass fibres adsorbed less proteins per weight unit (22 mg/g and 12 mg/g respectively for albumin and ferritin) than asbestos chrysotile fibres (42 mg/g and 49 mg/g respectively for albumin and ferritin).

Adsorption↗
PubMed1976

Beta2-microglobulin distribution in human normal tissues.

The distribution of beta2-microblobulin in human normal tissues was investigated by the indirect immunofluorescent antibody method. Lymphoid, macrophage and endothelial cells were consistently positive in every organ studied. In addition, only the stratum germinativum of the epidermis, some tracts of the columnar epithelium of the digestive system and some endometrial tubular glands showed a specific fluorescence.

Beta-Globulins↗
PubMedDate not supplied

[Measurement of airborne asbestos fibers on railroad rolling stock].

In February 1995 the Italian Railways Health Department set up a special study group in order to assess the effectiveness of the measures adopted against hazards due to the presence of asbestos in rolling stock currently in use on the rail network. The group set up specific procedures for sampling and analysis, on the basis of the criteria fixed for civil buildings in Ministerial Decree of 6/9/94, which was subsequently applied to rolling stock by Ministerial Decree of 26/10/95. In accordance with these procedures the study group carried out environmental studies via test runs programmed by the Railways Technical Departments, on trains made up of different types of vehicles. Insulated, completely or partially deinsulated and originally non-insulated vehicles were studied. Samples were analysed via scanning electron microscopy (SEM) with elementary dispersion X spectroscopy (EDXS) carried out by highly qualified public laboratories (ISPESL--National Institute for Prevention and Work Safety, ARPA--Regional Environmental Protection Agency, CRA--Veneto Region, University Departments). Altogether, from the start of the programme up to September 1998, 1464 samples in 170 test runs on 619 rolling stock vehicles were examined. These involved 83 locomotives, 83 electric rail-cars and 453 carriages. The results showed that in over 99% of the samples the fibre concentrations were below 2 fibres/litre, which is the value fixed by law for buildings and rail vehicles in order to qualify for effective decontamination status. Values exceeding 2 fibres/litre were found in only 4 vehicles, which were withdrawn or blocked for further checks. As a precaution, 18 vehicles where concentrations over 1 but less than 2 fibres/litre were found, were also blocked and their return to service has been postponed for further checks and analyses until the results show concentrations below 1 fibre/litre. Environmental analyses carried out up to the present indicate an overall situation comparable to that usually found in the general environmental without any asbestos dispersion sources. Surveillance and investigations are still under way in order to achieve the aims of the safety programme set up by the Italian Railways to ensure health and environmental protection.

Air Pollution, Indoor↗
PubMedDate not supplied

[Presence of asbestos in naval vessels: study of airborne fiber concentrations on Italian railways ferry boats].

Asbestos has been widely used on ships as an insulating material due to its fire-resistant and sound-absorbent properties. It was therefore deemed appropriate to measure the concentrations of airborne asbestos fibres on two ferries in regular service on the Civitavecchia-Golfo Aranci route. Decontamination work had been carried out on these vessels in order to remove, as far as possible, or to confine asbestos. Between 1994 and 1998, the Ultrastructures Laboratory of the Istituto Superiore di Sanità analysed 123 samples via scanning electron microscopy (SEM) with elementary dispersion X spectroscopy (EDXS). The results showed that in 98.4% of the samples concentrations in the air were below 2 fibres/litre, which is the value set by Ministerial Decree of 6/9/94 for buildings to qualify for effective decontamination status. Concentrations above this value, between 2 and 10 fibres/litre, were found in one ferry engine room, where workers were not continuously present since a remote control box was installed there. The results show that there is no environmental dispersion of asbestos fibres in usual navigation conditions; the situation is comparable to that in buildings where asbestos-containing safety materials have been used and that are subject to period checks in accordance with the guidelines included in Ministerial Decree of 6/9/94. Legislation is deemed necessary to make law 257/92 applicable to naval vessels in order to define univocal criteria for risk evaluation, checking, maintenance and custody procedures of asbestos-insulated vessels, and procedures for each job on board involving handling or removal of asbestos-containing material.

Air Pollutants↗