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Biomedical subjects

A Cavatorta

Publications and source records attributed to A Cavatorta.

At least 37 records · Page 2Linked to original sources
PubMed1983

Early indicators of renal damage in workers exposed to organic solvents.

In order to investigate the renal function, a cross-sectional study was carried out on four groups of workers significantly exposed to a mixture of alicyclic and aliphatic C5-C7 hydrocarbons, to styrene, to a mixture mostly composed of toluene and xylenes and to chlorinated hydrocarbons, respectively. The study involved 438 workers. Exposure was characterized by means of urinary metabolites, or by means of environmental measures, when biological indicators were not available. The renal function impairment indicators included total proteinuria, albuminuria and urinary excretion of muramidase (E.C. 3.2.1.17) and beta-glucuronidase (E.C. 3.2.1.31). The trend of these parameters provides some evidence of renal damage due to occupational exposure to organic solvents and suggests that the lesions are mild and tubular rather than glomerular.

Adult↗
PubMed1982

Neurophysiological effects of long-term exposure to hydrocarbon mixtures.

Motor nerve conduction velocity (MCV) was measured on median, ulnar and peroneal nerves in a reference group of 52 workers and a group of 95 workers exposed to hydrocarbon mixtures in a shoe factory. Exposure-related changes were found in motor action potential (MAP) amplitudes of the three nerves and in median and peroneal MCVs. Electroneurographic abnormalities were also present in a subgroup of workers exposed to air concentrations near the current ACGIH (1979) recommended threshold limit value (TLV) for the mixture. Our results suggest the need for lowering the TLV for the main components n-hexane and cyclohexane. A synergistic effect of the two hexacarbon solvent might also be considered in the hygienic evaluation of the workplace.

Action Potentials↗
PubMed1982

Neurophysiological changes in workers exposed to organic solvents in a shoe factory.

Motor conduction velocity (MCV) was measured in the median, ulnar, and peroneal nerves of 52 referents and 95 workers from a shoe factory, in a search for dose-effect and dose-response relationships between exposure to organic solvents and subclinical impairment of the peripheral nervous system (PNS). According to the environmental concentrations, the exposure was expressed as the sum of the products between the median hygienic effect (ranging from 0.08 to 2.89) and worktime (from 1 to 29 a) in every job. The motor action potential (MAP) amplitudes, durations and shapes of the exposed workers were significantly affected even if to a different extent and significance level when compared to those of the MCVs of the referents. The MCVs of the median (t = 3.17, p less than 0.01) and peroneal (t = 2.11, p less than 0.05) nerves were reduced as compared to reference values. In the exposed group, the MCV of the median nerve was negatively correlated with exposure score (r = 0.45, p less than 0.01) but not with age. No relationship was found between MVCs of the ulnar and peroneal nerves and exposure. The MCV of the median nerve was particularly slow in a subgroup of workers with an exposure score of greater than 20 (t = 2.30, p less than 0.05 vs the other exposed workers; t = 5.56, p less than 0.01 vs the referents). This exposure score represents only 50% of the maximum allowable score for a worktime of 40 a. Even if none of the examined workers showed clinical signs of polyneuropathy, evidence of subclinical effects on the PNS were found among subjects with long-term exposure to hexacarbon mixtures. Therefore, our results suggest the need for a lowering of current threshold limit values at least for n-hexane.

Adolescent↗
PubMed1981

Absorption and alveolar excretion of cyclohexane in workers in a shoe factory.

The lung uptake and excretion of cyclohexane were studied in five workers and three volunteers in a shoe factory. Air samples were collected from the breathing zones with personal samplers, and simultaneous samples of inhaled and alveolar air were collected with the aid of a Rhan-Otis valve. Cyclohexane was absorbed on activated NIOSH approved charcoal tubes. The uptake was calculated from the pulmonary ventilation, the retention coefficient and environmental concentration. Alveolar excretion was monitored during a 6 h post-exposure period. The amount of exhaled cyclohexane was calculated from the decay curve. According to experimental data, the alveolar retention of cyclohexane is about 34% of the inhaled dose. This corresponds to a lung uptake of 23%. The post-exposure alveolar excretion does not exceed 10% of the total uptake. The difference between respiratory uptake and excretion indicates that the amount metabolized may be very large. Nevertheless, the urinary excretion of the main metabolites, cyclohexanol and cyclohexanone, was only about 1% of the absorbed dose.

Absorption↗
PubMed1981

Organic solvents and chronic glomerulonephritis: a cross-sectional study with negative findings for aliphatic and alicyclic C5-C7 hydrocarbons.

Proteinuria, albuminuria, urinary beta-glucuronidase and serum creatinine were estimated in 182 workers exposed to organic solvents in four shoe factories, as well as 30 workers with past exposure and 80 control subjects. Ambient air concentrations at each workplace were also measured. In most of these samples, the concentration of organic solvents exceeded the ACGIH recommended threshold limit value for the mixture. Total protein excretion was significantly elevated in exposed workers, although none of the workers had abnormal albuminuria or serum creatinine. Four had increased lysozymuria. There was also a simultaneous elevation of beta-glucuronidase. These findings suggest that a mild and presumably reversible tubular lesion, but not glomerular damage, may occur in workers occupationally exposed to C5-C7 hydrocarbon mixtures.

Adult↗
PubMed1980

[Chronic non-specific disease of the respiratory system and measurable alterations in workers in the chromium-plating industry (author's transl)].

Lung function test performed on 26 chromium plating workers showed a high prevalence of obstructive disease and of change in DLCO. The connection between lung function impairment and occupational exposure to chromium is suggested by the relationship between respiratory changes and biological indices of chromium absorption. The prevalence and the severity of ventilatory impairment also show an increasing trend with the duration of the exposure, while the smoking habitus seems not to be important.

Adult↗
PubMed1980

[Spirometric alterations in chromium-exposed welders (author's transl)].

Lung function tests were examined on 28 welders using high chromium alloyed electrode for two years. Respiratory function change seem to be related to the duration of employment as welders. On the contrary, obstructive disease and alveolo-capillary impairment were found with same prevalence in groups of workers differently exposed to chromium. It presumably occurs because the exposure to chromium is quite short.

Adult↗
PubMed1978

Studies on the etiology of the experimental neuropathy from industrial adhesive (glues).

Chickens treated by paintbrushing with glue distillate (used in shoe industries), hydrocarbon mixture and TOCP in hexane, developed paralysis (4/5); in these, we have demonstrated a diffuse degeneration of the myelinic sheath of the peripheral and central neurites. Besides TOCP, cyclohexane (because of its higher concentration in the glue distillate and in the hydrocarbon mixture) may be indicated as responsible for occupational neuropathy.

Adhesives↗
PubMed1978

Nephrotoxicity of chromium. Remarks on an experimental and epidemiological investigation.

Observations conducted on a group of workers exposed to chromium (who showed a rapid urinary excretion of the metal and progressive increase of clearance with cumulative years of exposure), induced the authors to evaluate the nephrotoxic action of chromium in rats exposed to acute and chronic intoxication. The progressive Cr accumulation in the renal cortex during the course of testing explains the increase of the excreted fraction of filtered Cr, and therefore, the clearance, of the metal through the reduction of the tubular lumen-epithelium gradient. Paralleling the anatomical lesions (demonstrated only at the level of the proximal tubular cells), are the increasing modifications of the cellular lesion or altered reabsorption registered by several urinary indicators. Similar changes were found in subjects chronically exposed to the metal; their reversibility is linked to the possibility of repairing the epithelial damage by stopping exposure.

Animals↗
PubMed1978

[Relation between environmental concentration, urinary elimination and body burden of chromium in occupationally exposed workers].

Biological and environmental monitoring of chromium exposure was carried out on 20 welders working with special electrodes in the manufacture of tank-cars. The workers were divided in groups, according to the different degree of chromium accumulation, which was determined by renal clearance of diffusible chromium. A closed linear relationship between TWA concentration of hydrosoluble chromium in air and urinary excretion of the metal at the end of exposure was observed. The parameters of regression lines in welders with more (clearance 10 ml/min) or less (clearance 5 ml/min) accumulation of chromium suggest that the renal burden influences not only the basal excretion, but also the excretion at the end of exposure. We underline the difficulty in the determination of correct biological limits if we take them from TLV in air. We must at least consider the degree of accumulation in exposed workers too.

Air Pollutants↗
PubMed1977

[Clinical and muscle istochemical observations in secondary hypokalaemia (author's transl)].

A case of hypokalaemia due to chronic administration of Clortalydone is reported. The histochemistry of muscle biopsy showed the morphologic changes which are usually found in the muscle fibers of periodic familial paralysis (necrotic fibers, accumulation of PAS positive substance, inflammatory cells, intermyofibrillar network degeneration, increase of lipids content). Such findings suggest some clues to the pathophysiology of the essential hypokalaemic paralysis and the possible practical importance of these histopathologic muscular findings in the diagnosis of secondary hypokalaemia.

Aged↗
PubMed1977

[Chromium exposure biological indices and clinical findings in chromium plating industry (author's transl)].

According to the investigations carried out on workers of two chromium plating plants, the authors believe that chromium urinary excretion allows to determine the degree of its acute absorption. Moreover, the renal clearance of diffusible chromium allows the evaluation of chromium body burden and is related to the duration as well as to the severity of exposure. This interpretation is supported by the relation between the exposure biological indexes and the clinical and instrumental investigations which make possible the evaluation of lesions caused by chromium exposure, mostly concerning the respiratory system.

Body Burden↗
PubMed1976

Glycolipid modifications during peritoneal dialysis in patients with chronic renal failure.

Ten patients with progressive CRF were studied for the major indices of glycolipid metabolism during the first application of peritoneal dialysis. From the 2nd hour the concentration of dialysis fluid is 4.5g%, while the electrolyte content is unchanged. During treatment a constant increase of glycemia and insulinemia with a fall of plasma-free fatty acids and serum triglycerides was observed. The authors attribute such modifications to hyperglycemia and consequently to the high glucose of the dialysis bath.

Adult↗