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Biomedical subjects

A Betta

Publications and source records attributed to A Betta.

At least 19 recordsLinked to original sources
PubMed2001

Scleroderma and occupational exposure to hand-transmitted vibration.

OBJECTIVES: To determine whether occupational exposure to hand-transmitted vibration is a risk factor for scleroderma (systemic sclerosis, SSc), two case-control studies were conducted in the provinces of Trento and Verona, northeastern Italy. METHODS: In the Trento study, 21 patients with a diagnosis of either systemic or localised scleroderma were recruited from those admitted to all hospitals of the province from 1 January 1976 to 31 December 1991. For each case, two age- and gender-matched controls were selected. In the Verona study, cases included 55 patients diagnosed with SSc and clinically followed at the rheumatology clinic of the local university hospital between 1 January 1997 and 30 June 1999. The controls included 171 subjects frequency-matched by gender and age group. In both studies, all subjects were interviewed by structured questionnaire containing items on personal characteristics, smoking and drinking habits, use of medicines, occupational history and complete medical history. Women were also investigated about silicone implants and cosmetic surgery. Jobs and job tasks involving the use of vibratory tools, with or without concomitant exposure to silica dust in mining and non-mining occupations, were carefully investigated. A minimum criterion of 6 months was required for exposure duration. RESULTS: In the Trento study, men with scleroderma were more likely than controls to have had exposure to hand-transmitted vibration (odds ratio (OR) 1.5, 95% confidence interval (95% CI) 0.1-74.1) or silica dust (OR 5.2, 95% Cl 0.5-74.1), but the association was not significant. The scleroderma patients were miners or stone workers who had operated jackhammers and rock drills. In the Verona study, a greater, although not statistically significant, odds of SSc was observed in men exposed to hand-transmitted vibration (OR 2.4, 95% CI 0.4-14.0) and in women exposed to silica (OR 2.4, 95% Cl 0.4-15.5). The SSc patients with vibration exposure were machinery operators or metal workers who had used grinders and impact wrenches. CONCLUSIONS: Our case-control studies did not show a significant association between scleroderma and hand-transmitted vibration, with or without concomitant exposure to silica dust. Owing to the rarity of the disease and the small number of cases in the present studies, a genetic susceptibility to connective tissue disorders in SSc patients with occupational exposure to hand-transmitted vibration and/or silica cannot be ruled out.

Case-Control Studies↗
PubMed1997

Urinary excretion of ethylenethiourea in five volunteers on a controlled diet (multicentric study).

Urinary excretion of ethylenethiourea (ETU) was monitored for 8 days in a group of five male non-smoker volunteers on a diet, the items of which were assayed for ETU and carbon sulphide. Urinary excretion of ETU reflected the consumption of wine, fruit and vegetables. Urinary ETU concentrations ranged from 0.6 to 6.7 micrograms/g creatinine. ETU concentrations in the food eaten by the volunteers were generally below the detection limit whereas in wine 8.8 micrograms/l ETU was detected. Evolution of carbon sulphide by food samples ranged from 0.03 to 0.17 mg/kg. Mean (+/- S.D.) daily intake of ETU in wine was 3.5 +/- 0.2% of the acceptable daily intake (ADI): 0.070 +/- 0.004 micrograms/kg body wt. During the 8 days of the study, an average of 48.3% of the ETU ingested in wine was excreted unmodified by the kidneys. Twenty-four hour urinary excretion of ETU was significantly correlated with daily intake of ETU (r = 0.768) and CS2 evolved by the daily food items (r = 0.414).

Adult↗
PubMed1996

Reference values of urinary ethylenethiourea in four regions of Italy (multicentric study).

The results of a study in which urinary ethylenethiourea (ETU) was assayed in the general population (167 subjects) of four Regions of Italy (Veneto, Lombardy, Piedmont and Trentino Alto Adige) are reported. The results are compared with those in a population of 97 subjects from Rovescala, a hillside wine-producing town a few kilometers from Pavia, where ethylenebisdithiocarbamates are sprayed by helicopter. It was found that an average of 24% of the populations of the four regions, taken together, had urinary ETU levels above detection limits (1.0 microgram 1(-1)) as compared to 37% of the population of Rovescala. The ranges of concentration were 0.8-8.3 micrograms 1(-1) for the four regions and 0.9-61.4 micrograms 1(-1) for Rovescala. Statistically significant variables for urinary ETU levels were smoking and wine drinking.

Adolescent↗
PubMed1995

Scleroderma and occupational exposure.

OBJECTIVES: A case-referent study was conducted in the province of Trento, Italy, to investigate the possible association between occupational exposure and scleroderma (systemic and localized variants). METHODS: Twenty-one cases of scleroderma were ascertained from the computerized admission files of all of the local hospitals from 1976 to 1991. For each case, two age- and gender-matched referents were selected that were discharged from the hospital on the same day as the case. The subjects were interviewed with a structured questionnaire which included items for personal, work, and medical history. Exposure to organic solvents, other selected chemicals, silica dust, and hand-arm vibration was carefully investigated. RESULTS: A significant association was found between exposure to organic solvents (aromatic hydrocarbons) and scleroderma [odds ratio (OR) 9.28, 95% confidence interval (95% CI) 1.08-243.8]. For the men, the OR for exposure to silica was 5.20 (95% CI 0.48-74.1), whereas for the women it was 2.11 (95% CI 0.20-22.0) for exposure to other selected chemicals. CONCLUSIONS: The results of this case-referent study are consistent with those of previous case reports on the important role of occupation in the etiology of scleroderma. In particular, our findings confirm that exposure to organic solvents and silica is associated with this rare connective tissue disease.

Case-Control Studies↗
PubMed1994

Low-back disorders in agricultural tractor drivers exposed to whole-body vibration and postural stress.

The occurrence of low-back pain (LBP) was investigated in a population of 1155 tractor drivers exposed to whole-body vibration (WBV) and postural stress (response rate 91.2%) and in a control group of 220 office workers (response rate 92.2%). The subjects were questioned about several types of low-back symptom (LBP, sciatic pain, acute LBP, transient and chronic LBP) and various work- and individual-related risk factors, by using a standardized questionnaire. Vibration measurements were performed on a representative sample of the vehicles driven by the tractor drivers in the last ten years. Vibration magnitude and duration of exposure were used to calculate a vibration dose for each tractor driver. Perceived postural load was assessed in terms of frequency and/or duration of awkward postures at work. The prevalence of LBP was found to be greater in the tractor drivers than in the controls. After controlling for potential confounders by logistic modelling, low-back disorders were found to be significantly associated with both vibration dose and postural load. Back accidents and age were also significant predictors for LBP. Quantitative regression analysis indicated that vibration exposure and postural load were independent contributors to the increased risk for LBP according to a multiplicative model. The exposure levels for WBV recently recommended by a proposal of European Directive on physical agents seem to be more adequate to prevent long-term health effects on the lower back than the exposure limits suggested by the International Standard ISO 2631/1.

Journal Article↗
PubMed1992

Blood concentration of carbon disulphide in "normal" subjects and in alcoholic subjects treated with disulfiram.

Assay of free and acid labile carbon disulphide (free and total CS2 respectively) in human blood was performed by gas chromatography/spectrometry. The method used a large dynamic head space volume and a "cryogenic trap". Blood CS2 concentration was measured in 42 subjects not occupationally exposed to CS2 (group A) and in 11 alcoholic subjects (group B) treated with disulfiram. Free CS2 concentration showed a mean value of 261 ng/l in the 42 subjects in group A and 9482 ng/l in eight subjects of group B. Total CS2 concentration was 897 ng/l and 40,084 ng/l in groups A and B respectively. Differences between the groups were highly significant for concentrations of both free and total CS2. Total CS2 concentration was about four times as high as free CS2 concentration in both groups. A significant correlation was found between free and total CS2 concentration both in group A and in group B. In the alcoholic subjects (group B), blood concentrations of both free and total CS2 were related to time of sampling after treatment with disulfiram.

Alcoholism↗
PubMed1990

Physiological reactions during brush saw operation.

An experimental study of the physiological effects of brush saw operation was performed on eight professional agricultural workers. The experiments were carried out in the field under practical working conditions. Aesthesiometric thresholds (two-point discrimination and depth sense perception), manipulative dexterity, pinch grip force and fingertip skin temperature (FST) were measured before and after exposure to different combinations of static load (handle holding), noise and vibration by using new production brush saws for 5 to 15 min. The changes in the peripheral circulatory, sensorineural and muscular functions of the brush saw workers were not found to be significantly different under the various exposure conditions. Static load accounted for the major part of the changes in aesthesiometric thresholds, pinch grip force and FST after brush saw operation. With respect to baseline measurements, no significant difference in manipulative skill was observed after each exposure period. The weighted vibration accelerations from the right and left handles of a brush saw were 3.13 and 1.80 m/s2, respectively. The assessment of brush saw vibration exposure according to ISO 5349 and the results of FST measurements were consistent with the findings of some epidemiological surveys indicating a low risk of vibration-induced white finger among brush sawyers. This investigation pointed out that the increase in the aesthesiometric thresholds was mainly determined by handle holding, and that the reduction in gripping force during actual work was related to the duration of brush saw operation. Therefore, prolonged static overload on the nerves, muscles and joints of the hand-arm system could explain the increased risk of musculoskeletal and sensorineural disorders found among brush saw users.

Adult↗
PubMed1989

Physiological cost of apple-farming activities.

Seventeen agricultural male workers, aged between 21 and 56 years, were investigated in the field during six different job-activities of apple-farming: pruning, weeding, hand and mechanical spraying, mowing and picking. Pulmonary ventilation and oxygen consumption were recorded for short periods by Oxylog, while heart rate was monitored for more than 24 hours by Holter's method. The farmers also rated the work intensity according to Borg's RPE scale. Pulmonary ventilation ranged on average between 13 and 30 1/min and oxygen consumption between 500 and 1300 ml/min, with a relative aerobic cost between 15 and 40%, in the different work activities. Heart rate varied on average between 80 and 94 beats/min with a relative cardiac cost between 20 and 30%. The physiological criteria (oxygen uptake and cardiac response) and the subjective rating of fatigue gave a substantially similar evaluation of the work strain, 'moderate-heavy' for mowing, weeding and picking, 'moderate' for pruning and hand spraying, 'light' for mechanical spraying of pesticides. On the whole, apple-farming can be evaluated as 'moderate' intensity, thanks to the mechanisation implemented in reducing the work-load and the work-time of many job activities.

Journal Article↗
PubMed1983

Flicker fusion test and occupational toxicology: performance evaluation in workers exposed to lead and solvents.

1 In a group of 108 workers professionally exposed to low lead levels and in 35 shoe factory workers exposed to a mixture of solvents, neurotoxic effects were evaluated by means of Critical Flicker Frequency, used as single test of psychophysiological performance. 2 A statistically significant lowering of CFF threshold was observed and, in the lead exposed group, this decrease is related to the biological parameter zinc protoporphyrin. 3 The usefulness of CFF measure in environmental toxicology, together with other neurophysiological tests, is considered.

Adult↗
PubMedDate not supplied

Residential radon and risk of lung cancer in an Italian alpine area.

To evaluate whether residential radon exposure explains the excess mortality for lung cancer in an Italian alpine valley with high natural radioactivity, the authors conducted a population-based case-control study on 138 deceased cases and 291 sex- and year-of-birth-matched controls. Year-long alpha-track measurements of radon were performed in the most recent residence, and information about occupational history and lifetime smoking habits was obtained. The authors adjusted for smoking, and radon was associated with lung cancer risk among men: compared with a radon level of < 40 becquerels (Bq) per cubic meter (m3), the odds ratios for 40-76 Bq/m3, 77-139 Bq/m3, 140-199 Bq/m3, and 200+ Bq/m3 were 2.1, 2.0, 2.7, and 1.4, respectively. The association between radon and lung cancer, as determined with a multiplicative model, was found only among male smokers.

Aged↗
PubMedDate not supplied

Reference values of urinary 3,5,6-trichloro-2-pyridinol in the Italian population--validation of analytical method and preliminary results (multicentric study).

The interlaboratory validation of analytical procedures for the assay of urinary 3,5,6-trichloro-2-pyridinol (TCP) in the general Italian population is reported. The determinations were performed by high-resolution gas chromatography (HRGS) with electron capture detection and HRGS with mass spectrometry (MS) in 2 laboratories. The urine samples were from 42 participants from 3 regions of Italy. The results were evaluated by interlaboratory quality control. Urinary TCP concentrations were above the detection limit (1.2 micrograms/L) in 88% of the population, with a mean detectable concentration [GM (GSD)] of 2.8 (1.9) micrograms/g creatinine (creat). (GM, geometric mean; GSD, geometric standard deviation.) The Mann-Whitney U test showed that wine consumption was a statistically significant variable (p < 0.05) for urinary concentrations of TCP. Analysis of variance of the logarithm of urinary TCP versus wine consumption and diet showed a statistically significant fit. The model used explained 30% of the total variance: wine consumption and diet accounted for 37 and 17% respectively of the explained variance.

Adult↗
PubMedDate not supplied

[Guidelines for assessment and management of risks caused by benzene for workers at gas stations].

The European regulations classify gasoline as "carcinogenic agent" because of its content of benzene (> 0.1%). Consequently the preventive and protective actions towards the petrol station attendants prescribe, before all, the elimination of the agent or the reduction of the exposure and the risk to the minimum. Well known are currently a series of preventive measures able to produce appreciable reduction of the risk: reduction of the benzene content of gasoline, vapor recovery systems, self-areas or do-it-yourself, specific procedures for working. Exposure assessment is an essential step in order to establish the need for further preventive measure and to verify their efficacy. The exposure levels to gasoline of the petrol station attendants can be influenced by a variety of factors other than benzene air concentrations and therefore biological monitoring can give some sensible advantage in respect to air monitoring. Dosage of benzene in expired air, in urine, or in blood give a very good estimation of the exposure to benzene but they are not test largely practicable today, because analytical, economical, organizational reasons. Recent studies suggest that the dosage in urine of trans,trans muconic acid (ttMA) or phenil mercapturic acid can be useful biomarkers of recent exposure, even at low levels of exposure such as in filling stations. Exposure conditions to gasoline vapors in filling stations are rapidly changing thanks to some technological innovations and legal restrictions and the exposure levels are much below the occupational air standards, Toxicological and epidemiological data (although not yet conclusive at low doses) suggest to carry out however health and epidemiological surveillance programs for the working population. A program for the health surveillance and biological monitoring is here proposed: a clinical examination, integrated with haematological tests and biological monitoring tests, must be carried out in pre-employment and subsequently repeated yearly in the highest exposure conditions. When the exposure levels should decrease the examinations could be carried out every two years.

Benzene↗
PubMedDate not supplied

[Exposure to silicon carbide fibers in the production of carborundum].

Recent reports have shown that not only silicon carbide dusts but also fibres are liberated into the working environment during the various phases of silicon carbide production (using Acheson furnaces), thus creating a further potential health hazard. An environmental hygiene survey was conducted in a silicon carbide production plant with the aim of quantifying airborne dusts and fibres. Although dust levels were below 50% of the TLV, high concentrations of fibres were observed (analyzed via optical microscopy using the criteria for asbestos fibres), which in some locations reached levels of 2000 fibres/litre with means (GM) between 100 and 780 fibres/litre according to department. These results are assessed in the light of the growing interest of researchers in the experimental effects of silicon carbide fibres.

Carbon↗
PubMedDate not supplied

[Scleroderma and occupational risk factors: a case-control study].

In a hospital-based case-referent study of systemic sclerosis (SSc) and occupational risk factors (55 cases and 171 referents), an excess risk for SSc was observed in men with previous occupational exposure to solvents and certain chemicals (vinyl chloride, formaldehyde). SSc was associated, even though not significantly, with occupational exposure to solvents and silica among women. The possible role of occupational exposures in the etiology of SSc, as well as the methodological limitations of the present study, are discussed.

Case-Control Studies↗
PubMedDate not supplied

[Pesticide immunotoxicity].

Pesticides have been reported as altering immune functions in animals and man. The authors review published data from which it emerges that pesticide exposure is often associated with depressed humoral and cellular responses in mammals. The immunomodulating effects are affected by the route of administration and can also occur without general toxic effects, with a clear dose-effect correlation and for different dose levels. Immunotoxicity has also been investigated in workers occupationally exposed to pesticides: many kinds of effects are described, since many immunotoxicants have multiple effects on immune functions but the authors emphasize the importance of further studies carried out in workplace situations where exposure levels can be more accurately measured.

Animals↗