Systolic time intervals as a measure of left ventricular function in viscose rayon workers exposed to carbon disulfide.

In a group of viscose rayon workers exposed to carbon disulfide the systolic time intervals were calculated. They were determined from the simultaneous recording of an ECG, a phonocardiogram, and arterial pulse tracings. Results indicate a shortened left ventricular ejection time (lvet) and a prolonged isovolumetric contraction time (ICT), together with an increase in the ratio of ICT to LVET. These alterations, which occurred in the absence of any clinical signs or symptoms of heart disease, are interpreted as a consequence of an impaired left ventricular contractility, comparable to mild coronary dysfunction. Literature data support the hypothesis that the biochemical mechanisms involved in the effect of carbon disulfide on myocardial cells are (a) an interference with energy metabolism from the inadequate availability of thiamine and nicotinamide or a direct inhibition of cytochrome or (b) an interference with catecholamine metabolism and defective hormonal control of the energy utilization process. Impaired left ventricular function in rayon viscose workers exposed to carbon disulfide represents an early and highly sensitive sign of carbon disulfide intoxication, and the use of systolic time intervals as a noninvasive measure of myocardial performance may be a useful method for monitoring carbon disulfide exposed people.

Assessment of coronary heart disease risk among viscose rayon workers exposed to carbon disulfide at concentrations of about 30 mg/m3.

Total cholesterol, high-density lipoprotein cholesterol, triglycerides, blood pressure, and two coronary heart disease risk indices were assessed for a group of 70 male viscose rayon workers exposed to carbon disulfide (CS2) and individually matched for age, height, and weight with 70 male referents. Environmental CS2 levels were below 35 mg/m3 during 1972-1979. The study, undertaken to define some risk factors for coronary heart disease and to determine some parameters of lipid metabolism, found no differences between the group of CS2-exposed workers and the referents. Apart from a possible toxic effect directly induced by CS2 on the myocardium, the results suggest that CS2 exposure up to about 30 mg/m3 does not promote coronary atherosclerosis and hence does not increase coronary heart disease by this mechanism.

[Achilles reflexogram and hemodynamic parameters in the evaluation of thyroid function]. / Reflessogramma achilleo e parametri emodinamici nella valutazione della funzionalità tiroidea

Among the numerous techniques designed to explore thyroid function, two which examine important peripheral aspects are considered: Achilles osteotendinous reflectivity (determination of contraction time and relaxation time of the gastrocnemius muscle) and the response of the cardiovascular system to thyroid hormones (determination of the time of onset of Korotkoff's sound and that of the brachial sphygmic wave). Comparison of the results obtained with these two techniques in a group of 60 euthyroid subjects, 17 hypothyroid and 25 hyperthyroid cases, shows that the techniques are comparable as regards precision, reproducibility, and sensitivity and are of indubitable importance for the assessment of thyroid function through the study of two of its peripheral aspects.

[New therapeutic prospects in lead poisoning: alpha-mercaptopropionylglycine]. / Nuove prospettive terapeutiche nell'intossicazione da piombo: l'alpha-mercaptopropionilglicina.

The action of alpha-mercaptopropionylglycine has been studied in 27 subjects occupationally exposed to lead. In addition to improved efficiency of liver function, the results show a tendency to normalization of the various porphyrinic metabolism parameters considered. A significant increase was observed in erythrocyte dehydratase ALA activity together with an equally significant diminution in urinary excretion of delta-aminoleuvlinic acid. Urinary coprorphyrin and erythrocyte protoporphyrin IX values were also down. The tendency of metabolic changes to normalize as a result of the toxic action of lead suggests the use of alpha-mercaptopropionylglycine in the treatment of lead poisoning.

[Calculation of the systolic time as an index of thyroid performance]. / Il calcolo dei tempi sistolici come indice di funzionalità tiroidea.

Two methods for determining some features of cardiovascular behaviour in dysthyroidism are compared: time of appearance of the femoral sphygmic wave (as an expression of the cardiovascular response to thyroid hormones); systolic times, particularly tension time (as an expression of the contractile function of the myocardium only). Results in 52 euthyroid, hyperthyroid and hypothyroid subjects showed that systolic times (especially tension time) are more accurate and more discriminating in the assessment of thyroid performance. Measurement of this interval is thus proposed as an index for the appraisal of myocardial contractility in dysthyroidism, and as an additional means of evaluating thyroid performance.

[Epidemiological survey on symptomatology of subject exposed to carbon disulphide (author's transl)]. / Indagine epidemiologica sulla sintomatologia presentata da esposti a solfuro di carbonio

Some epidemiological parameters were recorded in a group of 185 workers of a rayon viscose factory. An higher prevalence rate of diseases and an higher relative risk for respiratory, digestive, cardiovascular and nervous morbidity in exposed people were found. In order to put into evidence the existence of chronic CS2 intoxication in non-occupationally CS2-exposed people, the authors suggest to investigate morbidity in people who live near these factories.

[Occupational asthma caused by cefmetazole and 7-aminocephalosporanic acid: description of a clinical case]. / Asma professionale da cefmetazolo ed acido 7-amino-cefalosporinico: descrizione di un caso clinico.

A case of professional asthma, following exposure to cefmetazole and 7-ACA, occurring in a non atopic subject with remarkable bronchial hyperreactivity, is described. From the diagnostic point of view the execution of specific bronchial stimulation tests was conclusive. It is probable that the occurrence of the illness is due, in this case, to the ability of the inhaled substances to cause inflammation in a subject with bronchial hyperreactivity, without inducing an immunologic mechanism.

[Passive smoking: a risk factor in the home environment]. / Fumo passivo: un fattore di rischio dell'ambiente domestico.

Recent studies of the health effects of air pollution have pointed out the importance of environmental smoke as a pollution source in household. Several studies showed that children or adults living with parents or other adults who smoke have an increased risk of several effects: respiratory illness in children, changes of respiratory function in children and adults, risk of lung cancer and risk of other cancer than lung cancer. A few epidemiological surveys have studied the relationship between passive smoking and lung cancer. The available epidemiological studies (10 case-control studies, and 3 prospective studies) have been identified and the results combined. There was a 35% increase of risk of lung cancer among nonsmokers living with smokers as compared with nonsmokers living with nonsmokers. However, adjustments due to some degree of misclassification of some nonsmokers who may be still exposed to other people's smoke, increased the risk, which was thus estimated as 53%. Furthermore, cancer risk deriving from cumulative household exposures to cigarette smoke was evaluated. Overall cancer risk increased progressively with the number of household members who smoked. These results were observed for both smoking-related cancer and other sites cancer. Finally, although some of these results need to be confirmed, recent views believe that sufficient evidence is provided that breathing other people's tobacco smoke cause health impairment and lung cancer.

Altered glucose tolerance in carbon disulfide exposed workers.

Oral cortisone glucose tolerance tests were performed in 66 CS2-exposed workers and in 66 individually matched control subjects. Results indicate a higher and significant (p less than 0.001) prevalence of latent diabetes in the CS2-exposed group (72.7%) as compared with the control group (16.7%), and the existence of a positive and significant (p less than 0.001) correlation between blood glucose values and exposure index. Possible mechanisms of action involving zinc metabolism and pyridoxine metabolism are discussed.

[Occupational diseases: considerations on a clinical case series]. / In tema di patologia professionale: considerazioni su una casistica clinica.

The authors examine cases of occupational diseases diagnosed between 1982 and 1988 in patients admitted to "Divisione di Medicina del Lavoro I Sezione di medicina del Lavoro del Dipartimento di Medicina preventiva, occupazionale e di comunità dell'Università di Pavia". The most frequent syndromes concerns the auditory apparatus (having losses or deafness due to noise) and the respiratory system, whereas new safety regulations have given rise to the disappearance of benzene-induced hematologic abnormalities. Most of, the "classical" features of occupational diseases have disappeared, since early diagnosis has permitted the adoption of opportune technical and sanitary measures. The authors emphasize the necessity for role of Occupational Medicine (ever following the sentences 179 and 206 of the "Corte Costituzionale") to be not prevention, but also diagnosis, treatment and rehabilitation; therefore there is a need, all over the country, for adequate structures for the diagnosis and treatment of the occupational diseases.

[Evaluation of trends in occupational pathology in clinical cases]. / Valutazione della tendenza della patologia occupazionale in una casistica clinica.

The study considered all patients admitted to the 1st Division of Occupational Medicine, Department of Preventive, Occupational and Community Medicine of the University of Pavia between January 1st 1989 and December 31st 1995 with a diagnosis of occupational disease. It was useful in illustrating the evolution of occupational disease as regards both changes in etiology and in the symptoms and systems involved. A decrease in the number of occupational diseases diagnosed from 1993 to 1995 was revealed, but it is difficult to draw any significant conclusions from these data since the need for hospitalization when diagnosing this type of disease has diminished greatly. Changes in legislation which have obliged employers to take precise preventive measures could also be partly responsible for this downward trend. The patients were, in almost all cases, at an initial stage of their disease. This is reassuring as far as the therapeutic and legal need for an early diagnosis is concerned. However, it remains unknown how often the causal relationship between work and disease was not suspected and therefore how many cases did not arrive to observation. Finally, the study confirmed the disappearance of some occupational diseases, such as benzene intoxication, common in the past, and the increase in "emerging" pathologies like allergies.

[Early effects of exposure to anesthetic gases and vapors. A critical review on the suitability of several indicators of the effect]. / Effetti precoci dell'esposizione a gas e vapori anestetici. Una rassegna critica sull'applicabilità di alcuni indicatori di effetto.

Apart from a risk excess of liver disease among operating theatre personnel and of spontaneous abortion in women exposed during pregnancy, no definitive conclusion can be drawn regarding health impairment among anaesthesiology staff. However, many studies pointed out that several adverse effects occur as a consequence of experimental, therapeutic and occupational exposure to inhalation anaesthetics. This paper reviews the early changes of the organ systems (hepatobiliary, renal, cardiac, hematopoietic, reproductive systems; immunologic functions; cytogenetic effects), which are considered to follow anaesthetics exposure, to evaluate their possible use as biological indices of effect. The liver microsomal enzyme system has received particular attention with the aim of clarifying the mechanisms involved in anaesthetics hepatotoxicity. An increased microsomal enzyme activity was observed in experimental conditions and in humans. This inductive effect, which reflects metabolic changes affecting liver function, is commonly considered the earliest sign caused by exposure to several chemicals (other than anaesthetics) and may be evaluated by means of biomarkers, among which the measurement of urinary D-glucaric acid excretion is a well established non-invasive tool. Urinary D-glucaric acid excretion represents the most promising early metabolic effect of the exposure to anaesthetics. However, its measurement is not yet suitable as an index of effect for use in biomonitoring practice. The main aspects to be studied in the future are the following: (i) the evaluation of urinary D-glucaric acid excretion in the acute and chronic exposure to low-dose anaesthetics to check the existence of a dose-response relationship; (ii) the study of other parameters (urinary enzymes, immunological profile, chromosome aberrations) in selected groups of exposed and control subjects, in which both exposure and confounding factors (age, gender, life style, former diseases) as well as concomitant occupational exposures should be carefully taken into account.

[Acute accidental poisoning by mercury vapors in the home environment]. / Intossicazione acuta accidentale da vapori di mercurio in ambiente domestico.

The authors report 2 cases of acute mercury intoxication due to accidental breakage of barometer on to a lit gas ring. Within 24-48 hours the subjects developed neurological, gastrointestinal and dermatological symptoms. A 24-hour urine sample contained 600 and 400 micrograms of mercury per liter respectively (reference value 0.1-6.9 micrograms/L); blood concentration of mercury was 130 and 100 micrograms per liter (reference value 1.7-9.9 micrograms/L). The patients were treated with penicillamine and daily excretion of mercury was monitored. The residual sources of pollution in the kitchen were identified and bonificated.

Electromyographic investigation in early diagnosis of carbon disulphide neuropathy: a study on 216 workers with different degrees of exposure.

An electromyographic (EMG) investigation was performed on 216 workers of a viscose rayon plant with different degrees of exposure to CS2. In the light of the data supplied by the survey the AA. maintain that meedle EMG is able to detect, probably better than other test, changes of PNS even if they are very slight, and to select subjects having a higher risk of suffering from neuropathies. Nevertheless, also because of its sensitivity, EMG seems to be less specific than other electrophysiological parameters such as maximal motor conductions velocity (MMCV), that is significantly altered in exposed people. Muscular changes may be connected to a specific effect of CS2 less surely than MMCV change. However, they might be considered as pointing to a predisposition to PNS illness and it seems advisable to eclude these subjects from CS2 exposure.