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Biomedical subjects

L Ambrosi

Publications and source records attributed to L Ambrosi.

At least 19 recordsLinked to original sources
PubMed2004

Needs, education and accreditation in occupational medicine in Italy.

In Europe, continuing medical education is one of the main instruments for improving physicians' performance and ensuring adequate health care for citizens. Recent regulations have made such continuing education compulsory in Italy. Considering the particular features of occupational medicine, the Italian Society of Industrial Medicine and Industrial Hygiene (S.I.M.L.I.I.) recently set up a specific education and accreditation programme for occupational physicians, called the "Excellence Accreditation Scheme". The programme is based on the findings of a survey among occupational physicians, carried out in collaboration with the National Institute of Occupational Safety and Prevention (I.S.P.E.S.L.), which enquired into their training and continuing education needs. The programme started in 2003, and its first edition-presented here-involved more than 400 physicians specialising in occupational health.

Accreditation↗
PubMed2004

Effects of methylmercury on the microvasculature of the developing brain.

The study, undertaken with the aim of further investigating the effects of methylmercury (MeHg) exposure on the developing brain, was performed in the cerebellum of chick embryos, chronically treated with a MeHgCl solution dropped onto the chorioallantoic membrane, and in control embryo cerebella. Quantitative evaluations, performed by cold vapour atomic absorption spectrophotometry, demonstrated a high mercury content in the chorioallantoic membrane, encephalon, liver and kidney of the treated embryos. The morphological observations showed severe neuronal damage consisting of degenerative changes of the granules and Purkinje neurons. The effects on astrocytes were even more severe, since they were extremely rare both in the neuropil and around the vessel wall. Compared with the controls, the cerebellar vessels of MeHg-treated embryos showed immature morphology, poor differentiation of endothelial barrier devices, and high permeability to the exogenous protein horseradish peroxidase. These findings support the hypothesis that MeHg-related neuronal sufferance may be secondary to astrocytic damage and suggest that the developmental neurotoxicity of this compound could also be related to astrocyte loss-dependent impairment of blood-brain barrier (BBB) differentiation.

Animals↗
PubMed2001

A novel approach for identification and measurement of hemoglobin adducts with 1,2,3,4-diepoxybutane by liquid chromatography/electrospray ionisation mass spectrometry and matrix-assisted laser desorption/ionisation tandem mass spectrometry.

The structural characterisation of the adducts formed by in vitro interaction of hemoglobin (Hb) with 1,2,3,4-diepoxybutane (DEB), the most reactive 1,3-butadiene (BD) metabolite, was obtained by liquid chromatography/electrospray ionisation mass spectrometry (LC/ES-MS) analysis of modified tryptic peptides of human hemoglobin chains. The reactive sites of human hemoglobin towards DEB and its hydroxylated derivatives (trihydroxybutyl (THB)-derivatives) were identified through the characterisation of alkylated tryptic peptides by matrix-assisted laser desorption/ionisation tandem mass spectrometry (MALDI-MS/MS). Based on this characterisation, a procedure was set up to measure the Hb-adducts of THB-derivatives by isotope dilution mass spectrometry with the use of a deuterated peptide standard. The results obtained here could permit optimisation of molecular dosimetry of BD-adducts, and extension of the analysis to the biological monitoring of occupational exposure to butadiene.

Alkylation↗
PubMed2001

Developmental effects of lead acetate on the chick embryo metanephros.

The developmental effects of lead acetate were studied in the chick embryo metanephros, the third renal rudiment that acquires morphological characteristics of functioning kidney already during the prenatal life. Lead exposure was obtained by applying a lead acetate solution on the chick embryo chorioallantoic membrane at the days 9, 10 and 11 of incubation. Quantitative evaluation of the lead concentration assessed by furnace atomic absorption spectrophotometry at the days 14 and 21 of incubation demonstrated metal presence both in the chorioallantoic membrane (CAM) and in metanephros (MN). The lead concentration was higher in CAM than in MN; the metal amount was similar in the CAM of 14 and 21 day embryos, but significantly higher in the 14day embryo MN than in the 21 day embryo MN. Morphological observations on metanephros tissue of control and lead-treated embryos were performed under light, electron transmission and electron scanning microscopes. Peculiar attention was devoted to the expression of the junctional protein connexin 43, the major component of the gap junctions in the renal cells. The results indicated that lead treatment does not intervene in the general differentiation of the metanephric nephrons. The lead is reabsorbed by the proximal tubule cells that are engulfed by endocytotic vacuoles and metal deposits and show long term degenerative changes. Expression of Cx43 protein and ultrastructure of gap junctions between proximal tubule cells appeared to be unchanged. The morphological aspects of the MN corpuscles and tubules agree with the suggestion of a lead cytotoxic effect but do not corroborate, at least in this experimental model, the view of primary damage exerted by lead on the gap junctions of the renal epithelial cells.

Abnormalities, Drug-Induced↗
PubMed1990

Effects of low exposure to inorganic mercury on psychological performance.

The effects of low exposure to inorganic mercury on psychological performance was investigated: the study groups included eight chronically exposed workers and 20 who were only occasionally exposed. These were compared with a control group of 22 subjects from the same plant who were not exposed to mercury. All subjects were administered the WHO test battery to detect preclinical signs of central nervous system impairment: the battery includes the Santa Ana (Helsinki version) test, simple reaction time, the Benton test, and the Wechsler digit span and digit symbol. In addition, the Gordon test was used to study personality profiles and the clinical depression questionnaire. Urinary mercury was used as indicator for internal dose. To this effect, urinary mercury observed in workers examined from 1979 to 1987 was evaluated. Of the pyschic functions explored by behavioural tests, only short term auditory memory was found to be impaired in the chronically exposed workers (p less than 0.05 compared with the controls). The chronically exposed workers were also found to be more depressed than those in the two other groups. No changes of visual motor functions were observed. The personality of the occupationally exposed workers was found to be considerably changed compared with that of the control group. On the basis of the results obtained and in view of urinary mercury mean concentrations in the exposed group which were 30-40 micrograms/l over the years, it is suggested that the TLV-TWA for mercury should be lowered to 0.025 mg/m3 and that the biological urinary exposure indicator for biological monitoring should be 25 micrograms/l.

Adult↗
PubMed1989

Methylcarbamate effects on Meckel's cartilages in the chick embryo.

On the basis of previous observations on the teratogenic effects of a variety of organophosphorus and methylcarbamate compounds on the avian skeletal apparatus, the Meckel's cartilage shape and structure were analyzed in carbaryl (1-naphthyl N-methylcarbamate) treated and control chick embryos of 9, 10, 12 days of incubation. The results indicate that both during normal development and under experimental conditions these cartilages undergo similar deformities, apparently subsequent to chondroblast death and regressive processes in the extracellular matrix. Since the macro- and microscopical cartilage alterations are significantly more frequent in the treated embryos than in the controls, a hypothesis is advanced that the methylcarbamate may increase the spontaneous tendency of the above mentioned cartilaginous anlagen to be affected by degenerative processes during embryogenesis.

Animals↗
PubMed1988

The proposal of the Italian Committee on Occupational Cardiology.

This paper describes a protocol of assessing specific working fitness of post-myocardial infarction patients proposed by the Italian Committee on Occupational Cardiology. After cardiovascular (cross-sectional echocardiography, Holter monitoring and maximal symptom-limited ergometric test) and psychological evaluation (CBA-2.0), two ambulatory ECGs were used during work to confirm the first judgement of specific work fitness expressed by occupational specialists. The preliminary results obtained in 106 uncomplicated male patients (mean age 49 +/- 8 years) show that: (i) return to work (89.6%) at 117 +/- 51 days after the acute event is mainly related to socio-occupational variables rather than to cardiovascular status; (ii) the results of the ambulatory monitoring usually confirm the first judgment of specific work fitness; (iii) heart rate responses recorded during work are unrelated to the judgment of fitness; and (iv) the repeatability of the results observed during the two ambulatory ECGs at work is good.

Adult↗
PubMed1987

[Criteria of the evaluation of the cause-effect relationship of toxic substances in the industrial environment].

The author at first analyses the concepts of exposure, biological monitoring and dose. Therefore, he takes into consideration the varieties of the occupational hazard underlining the more and more prominent role of the different co-factors causing occupational diseases. Then he examines the judgement of the legal criteria in theme of occupational diseases, coming to the conclusion that, for the diagnosis of chronic intoxications, it is difficult to recognise cause-effect relationship in industrial toxicology due to: poor knowledge of toxic action mechanism, incomplete information on metabolic-dysfunctions and last, the frequent interference of non occupational factors which are not always easy to identify.

Air Pollutants, Occupational↗