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Biomedical subjects

G Lasorsa

Publications and source records attributed to G Lasorsa.

9 recordsLinked to original sources
PubMed1998

Auditory dysfunction in occupational noise exposed workers.

Occupational noise-induced hearing loss (NIHL) is well known to be an epidemiologically relevant problem. The subjects affected with NIHL show alteration of hearing thresholds as well as a worsening of the cochlear analysis functions and, usually, an impaired speech discrimination in presence of background noise. The study has evaluated the relationships between hearing threshold and equivalent exposure lever per day (Lepd), age and working seniority in a homogeneous sample of occupationally noise exposed workers. Three subgroups were also selected to study the most important cochlear functions as well as nerve and central functions. The first subgroup (Nn) contained normal hearing workers exposed to non-hazardous noise, while the second (Bn) contained workers exposed to high level continuous noise during their work day without clinical evidence of NIHL. The third subgroup (Bd) included subjects affected with the typical 4 kHz notch exposed to the same noise conditions than subgroup Bn. The results show that the hearing impaired subjects have the worst overall cochlear performance; however also the normal hearing workers exposed to hazardous noise have worse performance than subgroup Nn, relatively to high frequency thresholds, frequency resolution, TEOAEs, DPOAEs, stapedial acoustic reflex dynamic parameters. The results suggest that these measures could be used in the monitoring of the NIHL as indicators of subtle alterations of the hearing function.

Acoustic Impedance Tests↗
PubMed1997

Minimal immunological effects on workers with prolonged low exposure to inorganic mercury.

OBJECTIVES: This study was carried out to investigate possible immunological changes in workers with prolonged low exposure to inorganic mercury in a fluorescent light bulb factory. METHODS: 29 immunological variables were examined in 34 workers with prolonged low level exposure to inorganic mercury (exposed workers) and 35 unexposed workers as the controls. The selected indicator of mercury exposure was concentration of mercury in the urine (U-Hg), which declined progressively from 36.0 micrograms/l in 1978 to 6.0 micrograms/l in the study year 1994. RESULTS: None of the exposed workers had ever shown signs of either acute or chronic inorganic mercury toxicity or had shown any form of hypersensitivity. The only changes found in the exposed workers, compared with the controls, were a reduction of the cells that express cluster differentiation (CD25,(T activation antigen (Tac antigen))) and concentrations of tumour necrosis factor-alpha (TNF-alpha) in serum. However, the decrease of cells that express CD25 was unrelated to occupational exposure and was, in all likelihood a chance finding. Conversely, the decline in serum TNF-alpha was closely associated with occupational exposure. However, no dose-response relation was found between U-Hg and TNF-alpha concentrations; nor were TNF-alpha concentrations affected by cumulative occupational exposure to inorganic mercury in over 20 years. CONCLUSIONS: Tentatively, we suggest that reduced serum TNF-alpha concentrations might be indicative of an in vivo functional defect of the monocyte macrophage system in this particular group of workers even though they were clinically asymptomatic.

Biomarkers↗
PubMed1985

[Changes in the erythrocyte in liver cirrhosis: role of cholesterol and plasma phospholipids].

To investigate the role played by plasmatic lipids in the altered erythrocyte deformability observed in cirrhotic patients we studied 15 patients with liver cirrhosis (histologically diagnosed) and 10 healthy volunteers. Erythrocyte filtration time, plasmatic free and esterified cholesterol and phospholipids were measured in all subjects. The erythrocyte filtration time resulted to be significantly increased in cirrhotic patients (35'' +/- 3, 35 M +/- SEM) when compared to control subjects (26'' +/- 2, 53: M +/- SEM) (t = 2,078 p less than 0,05). This increase correlated in cirrhotic patients (but not in control subjects) with free/esterified cholesterol ratio (p less than 0,01) as well as free cholesterol/phospholipid ratio (p less than 0,001). Our results confirm that decreased erythrocyte deformability in cirrhotic patients which is accompanied by altered erythrocyte morphology is due, at least in part, to the altered lipids blood levels.

Cholesterol↗
PubMedDate not supplied

[Evaluation of noise-induced injury: consideration of a group of exposed cement workers].

The study covered 1334 workers employed in 12 cement factories located in southern Italy. They were submitted to audiometric screening consisting of a questionnaire containing questions on past otologic complaints, metabolic diseases, use of ototoxic drugs and past occupational or non-occupational exposure to noise, plus otoscopic examination and full audiometric examination. The results revealed a statistically significant relationship between duration of exposure to noise and elevation in the hearing threshold. The highest noise levels were found in the "crude/baked mills" department; however, the highest frequency of occupational hearing loss was observed in the "mine and crushing installations", maintenance and "hodmen" departments. On the question of assessment of the audiometric tracings for preventive and insurance purposes, attention is drawn to the fact that there is a need for a method that will enable an evaluation for prevention to be transformed into an evaluation for insurance. This method should in any case allow for deduction of the portion of hearing loss regarding presbycusis and socioacusis and take due account of the 3 KHz frequency. The attention of industry and public administration is drawn to the urgent need for prevention programs to protect against noise-induced hearing loss in both occupational and non-occupational settings.

Adult↗
PubMedDate not supplied

[Clinico-statistical investigation about cement dermatitis in Italy].

To define the prevalence of cement dermatitis (allergic contact dermatitis-ACD-and irritant contact dermatitis-ICD), two retrospective studies have been carried out in Italy: the first one based on the analysis of dermatitis cases ascribable to cement as defined by INAIL (Italian Institute for Industrial Accidents Insurance) from 1984 to 1992; the second one by surveying cement dermatitis cases in workers in the building industry aged between 16 and 70 carried out by Istituto di Clinica Dermatologica dell'Università di Bari from 1988 to 1994. The survey on INAIL data showed that in the years take into account 5,290 dermatitis cases included in item 41 of the occupational diseases table have been defined. About 80% of these cases have been observed in workers working as bricklayers and floor-layers. Therefore, given the remarkable exposure to cement in these professions, the prevalence of cement dermatitis in Italy has been estimated to 6 cases/province/year, even though it has not been possible recognize the clinical form of cement dermatitis. Moreover, the study showed that disabling cutaneous after-effects eligible for compensation have been observed in 30% of the cases defined by INAIL. The allergologic study carried out by Clinica Dermatologica has not only defined the incidence of contact dermatitis (ACD and ICD), in building workers, but it has also extrapoled dermatitis cases due to cement. As a whole, in the years taken into account, 166 occupational or mixed ACD cases and 77 occupational or mixed ICD have been diagnosed. The incidence of contact dermatitis ascribable to cement has equalled 79% among ACD and 88% among ICD, with a ratio of about 2 to 1 in favour of allergic forms. Among the chemicals tested, potassium bichromate showed the highest frequency of cases positive to patch tests. The skin site the most affected by cement dermatitis is hand, followed by upper limbs, lower limbs and feet. In the province of Bari, in the years taken into account, an average incidence of 28.4 cases per year of the two forms of cement dermatitis has been observed.

Adolescent↗
PubMedDate not supplied

The influence of amalgam fillings on urinary mercury excretion in subjects from Apulia (southern Italy).

The purpose of this study was to assess the role of dental amalgams and diet upon urinary mercury (U-Hg) excretion. 98 subjects (50 men and 48 women) not exposed to inorganic mercury, for either occupational or environmental reasons, and living in coastal and inland districts of Apulia (Southern Italy) were considered. All the subjects were administered a questionnaire with questions concerning life style, medical history, and occupational activity. Dental amalgams were evaluated with respect to their number and their surface areas. Urinary mercury was measured by the cold vapour atomic absorption technique. Expressed in terms of arithmetic mean, U-Hg excretion was found to amount to 1.03 micrograms/g creatinine (5th and 95th percentile: 0.31 and 2.40; range 0.30-3.25). Multiple linear regression analysis showed that, of the several tested independent variables (dental amalgams, age, body mass index, consumption of tuna, bass, swordfish, etc.), only the number of amalgam fillings (T = 5.25; p = 0.025) and the number of restored surfaces (T = 2.33; p = 0.020) were found liable to affect urinary mercury excretion in a significant manner. In conclusion, the results of this study confirm the primary role of amalgam fillings in affecting urinary mercury excretion in those subjects who are not occupationally exposed to inorganic mercury, The resulting urinary mercury levels can no doubt be taken as the reference values for the population of Apulia.

Adolescent↗
PubMedDate not supplied

[Dental amalgams and urine elimination of mercury in workers exposed to low concentrations of inorganic mercury].

The aim of the research was to assess the contribution of dental amalgams and other non-occupational factors of exposure to inorganic mercury (diet, etc.) to the quantity of mercury excreted with urine in workers exposed to low level concentrations of inorganic mercury. Two groups of workers (Groups I and II) were studied who were exposed to low and different environmental concentrations of inorganic mercury. These two groups were compared with a group of subjects not occupationally exposed to mercury in the same geographical area (Group III). All subjects were administered a questionnaire concerning personal data, lifestyle, recent removal and/or insertion of dental amalgam fillings, presence of nasal obstruction or bruxism and consumption of fish. The number of amalgam-filled teeth was established for each subject. Mean environmental exposure to inorganic mercury was 0.0087 mg/m3 for Group I and 0.0030 mg/m3 for Group II. Urinary excretion in the 3 groups was 4.2 +/- 2.8 micrograms/l for Group I, 3.0 +/- 2.1 micrograms/l for Group II and 1.6 +/- 1.2 micrograms/l for Group III. The results showed that of the factors of exposure to inorganic mercury, only occupational exposure (T = 9.18; p = 0.000) and the number of amalgam-filled teeth (T = 2.03; p = 0.043) were able to influence significantly urinary excretion of mercury; the sources of non-occupational exposure did not appear to play any role. The contribution of each amalgam filling to urinary mercury excretion was calculated to be 0.08 microgram/l. Occupational exposure therefore, even at low level doses, is still the main cause of urinary mercury excretion in workers exposed to inorganic mercury; of the non-occupational exposure factors, a significant role is played by amalgam dental fillings, whose contribution needs to be taken into consideration in order to make a correct interpretation of the results of biological monitoring of exposed workers.

Adult↗