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Biomedical subjects

G Marcuzzo

Publications and source records attributed to G Marcuzzo.

10 recordsLinked to original sources
PubMed1996

Otoneurological study in workers exposed to styrene in the fiberglass industry.

Twenty workers exposed to styrene and acetone in small fiberglass factories were monitored for 8 h using passive dosimeters. Urine samples were collected at the end of the workshift and before the start of work on the next morning. The 8-h time-weighted average exposure values for styrene and acetone ranged from 14 to 416 mg/m3 and from 70 to 277 mg/m3, respectively. The sum of styrene metabolites, mandelic acid and phenylglyoxylic acid (MA + PGA), in the next-morning urine samples ranged from 81 to 943 mg/g creatinine. Different test sensitivity was identified in the otoneurological battery: it was low for audiometric tests and ABR, and relatively high for vestibular tests. The vestibular system seems partially sensitive to the toxic effects of styrene in the absence of clinical signs and symptoms. The actual exposure levels for styrene cannot be considered devoid of functional subclinical consequences.

Acetone↗
PubMed1993

Biological monitoring of workers exposed to styrene and acetone.

Twenty-two workers exposed to styrene and acetone in two fiberglass industries were monitored on Monday and Thursday for 8 hours using passive dosimeters. Urine samples were collected at the end of the workshift and before the start of the work on the next morning (Tuesday and Friday). The charcoal disks of the passive dosimeters were analysed by gas-chromatography. Mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured using a HPLC method; values were expressed in mg/g of creatinine. The 8-h TWA exposure values for styrene and acetone ranged respectively from 22 to 522 mg/m3 and 40-1581 mg/m3 on Monday; 25-423 mg/m3 and 55-579 mg/m3 on Thursday. Styrene TWA exposure values significantly correlate with the sum of metabolites at the end of workday (r = 0.70 on Monday and r = 0.95 on Thursday) and also at the next morning (r = 0.86 on Tuesday and r = 0.85 on Friday). A styrene exposure level of 213 mg/m3 (ACGIH-TLV) was associated with an excretion of metabolites (MA+PGA) higher on Thursday (803 mg/g creat) than on Monday (570 mg/g creat). The same result was found on Friday (459 mg/g creat) compared with Tuesday (305 mg/g creat). Moreover our data show that the simultaneous exposure to acetone does not modify the excretion of MA. In conclusion the TLV of styrene is associated with different values of metabolites at the beginning and at the end of the work-week.

Acetone↗
PubMed1992

Helicobacter pylori and luminal gastric pH. Relationships in nonulcer dyspepsia.

The relationships between gastric pH and Helicobacter pylori infection were studied in 37 consecutive subjects affected with nonulcer dyspepsia. Each underwent esophagogastroduodenoscopy with multiple gastric biopsies for both H. pylori and histologic assessment, and 24-hr antral pH monitoring. H. pylori was harbored by 59.5% of the subjects with whole gastric spread of infection in all but one patient. Histologic gastritis was shown in 70.3% of the subjects. H. pylori was strongly associated with gastritis, both antral nonatrophic and multifocal atrophic. The ranges of 24-hr pH values were 1.3-6.9 in the H. pylori-positive and 1.2-6.8 in the H. pylori-negative group. Differences in pH values between the two groups were not significant. Moreover, the mean percent time duration of pH above 2, 4, and 6 did not significantly differ between the two groups. Therefore, this study has shown that chronic H. pylori infection is not related to luminal gastric pH.

Adult↗
PubMed1985

Relationship between mixed acid-alkaline gastroesophageal reflux and esophagitis.

The severity of reflux esophagitis is related to the potency of refluxed material and the duration of its contact with the esophageal mucosa. The occurrence of esophagitis in patients with gastric hyposecretion or even with achlorhydria has focused attention on nonacid gastroduodenal contents. Until analytical studies of refluxed material are available to clarify its composition, the 24-hour combined gastric and esophageal pH monitoring can be used for detecting gastroesophageal reflux and for trying to analyze the composition of the refluxate. The first problem of this investigation was to examine whether the mixed acid-alkaline reflux, defined by pH monitoring, represented reflux of duodenal content; the second to study if there was a correlation between this type of gastroesophageal reflux and esophagitis. Unequivocal grade II and III esophagitis were considered. Our data suggest that the mixed acid-alkaline gastroesophageal reflux represents reflux of duodenal contents into the stomach and successively into the esophagus. The higher incidence of endoscopic-proven esophagitis in patients with mixed acid-alkaline gastroesophageal reflux in comparison to patients with acid gastroesophageal reflux supports the concept that biliary and pancreatic secretions may be a contributory factor in esophageal injury.

Acids↗
PubMedDate not supplied

[The occupational risks in a company producing aluminum alloy wheels].

An environmental hygiene study was carried out in a factory making aluminium alloy wheels via pressure moulding. Physical risk factors (noise and microclimate) and chemical risk factors (respirable dust, mineral oils, solvents, fluorides, formaldehyde, CO) were assessed. Analysis of the data showed that physical risk factors were prevalent, whereas chemical pollution was insignificant due to technical improvements made by the management in the course of several redesigns of the plants.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Pollution by nitrous dioxide during diagnostic laparoscopy interventions].

Here we have outlined the data relative to an environmental survey carried out in a laparoscopy clinic at the hospital of Padua, to determine the environmental concentration of nitrous dioxide (N2O) used for intra-abdominal inflation during diagnostic laparoscopy interventions. The data obtained have revealed cases of considerable N2O environmental pollution. This above all, due to spontaneous loss of gas during the intervention and to the lack of adequate ventilation systems.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Interference of acetone in styrene metabolism in subjects exposed to both solvents].

Thirty-seven workers exposed to styrene and acetone in fiberglass industry were monitored on Monday and Thursday for 8 hours (two subsequent samplings of 4 hours each) using passive dosimeters (mod. TK200). The charcoal disks of the passive dosimeters were analysed by gas-chromatography. Urine samples were collected at the end of the workshift and before the start of the workshift the next morning (Tuesday and Friday). Mandelic acid (MA) and phenylglyoxylic acid (PGA) were measured in the urine, using a HPLC method; values were expressed in mg/g of creatinine. The 8-h TWA exposure values ranged from 10 to 522 and 13 to 1581 mg/m3 on Monday and 8 to 423 and 10 to 579 mg/m3 on Thursday for styrene and acetone, respectively. Styrene TWA exposure values significantly correlated with the sum of metabolites at the end of workday (r = 0.72 on Monday and r = 0.91 on Thursday) and also the next morning (r = 0.88 on Tuesday and r = 0.85 on Friday). A calculated styrene exposure level of 213 mg/m3 (ACGIH-TLV) was associated with an excretion of metabolites (MA+PGA) higher on Thursday (814 mg/g creat.) than on Monday (600 mg/g creat.). The same observation was made on Friday (409 mg/g creat.) as compared with Tuesday (302 mg/g creat.). In conclusion, the TLV of styrene was associated with different values of metabolites at the beginning and at the end of the work-week. Moreover our data show that the simultaneous exposure to acetone does not modify the excretion of MA.

Acetone↗