PubMed Health⌕ Search

Biomedical subjects

M Imbriani

Publications and source records attributed to M Imbriani.

At least 19 recordsLinked to original sources
PubMed1992

Serum albumin and others parameters in intravenous drug users HIV-infected.

In 37 intravenous drug users (IVDUs) in the first stages of HIV-infection (17 in stage II and 20 in stage III according to CDC), compared with 32 IVDUs HIV-negatives, we found a significant decrease in circulating leucocytes (p less than 0.01), lymphocytes (p less than 0.005), platelets (p less than 0.005), serum albumin (p less than 0.005), and C3 (p less than 0.02) and significant increase in serum gammaglobulins (p less than 0.0005) and IgG (p less than 0.0005). On the other hand no difference was observed in hemoglobin and in IgA levels; nevertheless an inverse relationship between serum IgA and CD4+ lymphocytes was present in HIV-positive (HIV+) patients (r = -0.34; p = 0.04). This observation agrees with that is observed in the advanced stages of HIV-infection, which presents an increase in IgA serum levels. In these stages this fact could be due to a decrease of secretory IgA, with a deficient barrier effect; the consequent recirculation of intestinal antigens should enhance the antibody production, as well as serum IgA. In the IVDUs HIV-infected a reverse correlation between albumin serum levels and the length of HIV-positivity (r = -0.44; p = 0.008) and a direct correlation between albumin serum levels and circulating CD4+ lymphocytes (r = 0.37; p = 0.05) were present. There was no direct linear relationship between albumin serum levels and creatinine, on the contrary to what was observed in the control group. The decrease of albumin levels could have a prognostic value as in other clinical conditions, in which it is associated with a higher mortality risk. Many factors could act to decrease albumin levels, but the most important one is perhaps the malnutrition of HIV-infected patients that can also be present in the first stages of infection, negatively influencing the associated immunodeficiency.

Adult↗
PubMed1991

Biological monitoring of the occupational exposure to halothane (fluothane) in operating room personnel.

The concentration of halothane (fluothane) in the ambient atmosphere was determined in five operating theaters of two hospitals in Italy. The concentrations of halothane in the ambient air exceeded the NIOSH recommended time-weighted average exposure levels (median value: 10.38 mg/m3). Halothane was detected in the urine of 58 exposed subjects (anesthetists, surgeons, and nurses). A significant correlation was found between the halothane concentration in urine produced during the shift (Cu, micrograms/L) and halothane environmental concentration (CI, mg/m3) (Cu = 0.242 x CI + 3.51) (N = 58; r = 0.92; p less than 0.0001). The results show that the urinary halothane concentration can be used as an appropriate biological exposure index. The biological values proposed are: 92 micrograms/L, corresponding to a 50 ppm of environmental exposure; 6.5 micrograms/L, corresponding to 2 ppm of environmental exposure and 3.9 micrograms/L, corresponding to a 0.5 ppm of environmental exposure.

Adult↗
PubMed1991

Acquired dyschromatopsia among styrene-exposed workers.

We investigated the occurrence of color vision loss in 75 styrene-exposed workers and in 60 referents. Color vision was evaluated by adopting the Lanthony D 15 desaturated panel, a test specifically suited to detect mild acquired dyschromatopsia. The results of the test were expressed as Color Confusion Index. Styrene exposure was evaluated with both environmental and biological monitoring. Airborne levels of the solvent were 3.2 to 549.5 mg/m3. In styrene-exposed workers color vision was significantly impaired when compared with referents matched for age. A significative correlation was found between environmental and urinary levels of styrene and Color Confusion Index excluding the influence of age in multiple regression analysis, indicating the possibility of a dose-effect relationship. The findings suggest that styrene can induce an early appearance of a dose-dependent color vision loss.

Adult↗
PubMed1990

1,2-Dichloropropane hepatotoxicity in rats after inhalation exposure.

The hepatic effects of 1,2-dichloropropane (DCP) were investigated in male Wistar rats exposed to 15, 50, 100, 250, 450, 1000, 1300, 1800 or 4900 mg DCP m-3. At the end of a 4-h period of exposure, average blood DCP levels were 0.025 and 5.38 micrograms ml-1 in animals treated with 15 and 1300 mg m-3, respectively. Blood DCP concentrations were correlated with the air DCP concentrations in the inhalation chamber. At DCP concentrations of 100 mg m-3 or higher, the liver non-protein thiol (NPT) content was significantly reduced. Assays performed 20 h after 4-h DCP exposure showed that exposure to 100-1000 mg DCP m-3 had no effect on hepatic NPT levels. The NPT content increased only in the liver of rats exposed to higher (1300-4900 mg m-3) DCP concentrations. Treatment with DCP did not cause hepatic lipid peroxidation and did not modify total protein content. The observed changes in liver cell thiol homeostasis are likely to reflect the action of reactive intermediates formed during DCP metabolism. These changes can occur in rats following exposure to considerably low levels of DCP vapour.

Administration, Inhalation↗
PubMed1989

[Occupational asthma].

Bronchial asthma has been defined as a state of airway obstruction of variable degree correlated casually with exposure to volatile dusts, gases, vapours or fumes in the working environment. In this review we considered the causes of occupational asthma, the diagnosis, the pattern of asthmatic reactions and their mechanism, the predisposing factors, the epidemiology, the prognosis and finally the cure and prevention (review article, 165 references).

Asthma↗
PubMed1989

Methyl ethyl ketone (MEK) in urine as biological index of exposure.

Fifteen human volunteers were exposed to methyl ethyl ketone (MEK) vapor at 11.9-621.8 mg/m3 for a period of 2 to 4 hours at rest (ten cases) and during light physical exercise (five cases). Subsequently 78 workers occupationally exposed to MEK in a manufacture of leather suitcases (median value: 75.5 mg/m3; geometrical standard deviation: 3.12 mg/m3; range: 6-790) were studied. The analyses were performed by means of a Gas Chromatograph (GC) Hewlett-Packard 5880 A connected with a Mass Selective Detector (MSD). The relative uptake (R) of MEK was about 0.54 (standard deviation: 0.05) and it keeps practically constant either at rest or during light effort (V < 30 L/min). A linear relationship existed in the experimentally exposed subjects between urinary concentration (Cu) and amount of MEK absorbed (U) (Cu = 3.05 x U-162.1; r = 0.95; n = 15) (Cu = micrograms/L; U = mg). Both in the experimentally exposed subjects and in the occupationally exposed workers, the urinary concentration of MEK shoved a linear relationship to the corresponding environmental time-weighted average concentration (CI). The correlation coefficients (r) were 0.93 in occupationally exposed subjects (regression equation: Cu = 0.004 x CI + 0.118; n = 78); Cu = mg/L; CI = mg/m3) and more than 0.93 in experimentally exposed groups. The findings indicate that the urinary concentration of MEK can be used as an appropriate biological exposure indicator.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1988

1,1,1-Trichloroethane (methyl chloroform) in urine as biological index of exposure.

Fifteen human volunteers were exposed to 1,1,1-trichloroethane (methyl chloroform) vapor at 72-495 mg/m3 for a period of 2 to 4 hours at rest (ten cases) and during light physical exercise (five cases). Subsequently 60 workers occupationally exposed to 1,1,1-trichloroethane in a refrigerator manufacturing plant were studied (median value: 178 mg/m3; geometrical standard deviation: 2.19 mg/m3). As expected, the relative uptake (R) of 1,1,1-trichloroethane decreased in the course of exposure at rest (R = 0.44 after 20 minutes of exposure; R = 0.26 after 240 minutes of exposure). Both in the experimentally exposed subjects and in the occupationally exposed workers, the urinary concentration of 1,1,1-trichloroethane showed a linear relationship to the corresponding environmental time-weighted average concentration. The correlation coefficients (r) were 0.95 in occupationally exposed subjects and more than 0.90 in experimentally exposed groups. A linear equation also existed between urinary concentration and amount of 1,1,1-trichloroethane absorbed (r = 0.88). The findings indicate that the urinary concentration of 1,1,1-trichloroethane can be used as an appropriate biological exposure indicator. In occupationally exposed subjects performing moderate work, the urinary 1,1,1-trichloroethane concentration corresponding to the time-weighted average of the threshold limit value was found to be 860 micrograms/L and its 95% lower confidence limit (biological threshold) 805 micrograms/L.

Adult↗
PubMed1988

Evaluation of exposure to isoflurane (Forane): environmental and biological measurements in operating room personnel.

The concentration of isoflurane (Forane) in the ambient atmosphere was determined in 11 operating theaters of 5 hospitals in Italy. The concentration of isoflurane in the ambient air exceeds the recommended time-weighted average exposure levels (median value: 113 mumol/m3). Isoflurane was detected in the urine of 45 exposed subjects (anesthetists, surgeons, and nurses). A significant correlation was found between the isoflurane concentration in urine produced during the shift (Cu' nmol/l) and isoflurane environmental concentration (Cl' mumol/m3) (Cu = 0.243 X Cl + 3.712) (r = .90). The results show that the urinary isoflurane concentration can be used as an appropriate biological exposure index. The authors suggest a biological exposure index of 18 nmol/l (3.4 micrograms/l). This is the biological value obtained after 4 h of an average environmental exposure to 81 mumol/m3 (2 ppm).

Adult↗
PubMed1988

Urinary concentration, environmental concentration, and respiratory uptake of some solvents: effect of the work load.

The physical demands of the workplace differ depending on specific jobs. This implies that workers exposed to the same environmental level of an airborne contaminant can absorb different amounts of it depending on their pulmonary ventilation. Starting from the relationship between the uptake (U) and the urinary concentration of six solvents (Cu) (acetone, styrene, toluene, xylenes, methylchloroform, tetrachloroethylene) and from the equation expressing their lung uptake (U = K.V.CI.R.T) the expected values of a biological index after a given time of exposure can be derived. Such values are a function not only of the environmental level of exposure (CI) but also of the pulmonary ventilation (V - dependent solvent) and of the retention index (R) (V - R dependent solvent).

Air Pollutants, Occupational↗
PubMed1988

[Vitiligo appearing after contact with mud containing solvents: an occupational cause?].

The authors describe one case of Vitiligo in a worker employed in a firm for the exploitation of underground energetic products. The disease occurred after contact with the mud used for the drilling containing aromatic, aliphatic and chlorinated hydrocarbons. The possible occupational cause of the disease, as more solvents in the mud have the structure of aromatic hydrocarbons is discussed.

Humans↗
PubMed1987

Methemoglobin and carboxyhemoglobin levels in smokers and non smokers.

The authors examined the blood of 856 subjects (377 smokers and 479 non smokers) in order to evaluate the levels of Methemoglobin (MetHb) in relationship to tobacco smoke. The Methemoglobin, Carboxyhemoglobin, Percent Oxyhemoglobin and Total Hemoglobin were measured using an automated spectrometer (IL 282 CO - Oximeter). The authors found that the levels of MetHb in the smokers exceed that in the non smokers: in fact the level of MetHb in the smokers (% MetHb = 0.63) was significantly greater than in the non smokers (% MetHb = 0.56), unlike what was reported in literature. The levels of Carboxyhemoglobin in the blood has been shown to be a useful marker of tobacco smoke absorption: a close relationship exists between COHb and cigarette smoking.

Adolescent↗
PubMed1987

[Use of gas chromatography with flame ionization (GC-FID) in the measurement of solvents in the urine].

The urinary concentration of some solvents (acetone, cyclohexane, 1,2 dichloropropane, n-hexane, methyl ethyl ketone, perchloroethylene, styrene, toluene, 1,1,1, trichloroethane) was measured by means of a gas chromatography Hewlett-Packard 5890 supplied with a flame ionization detector (GC-FID, DANI HS 3950). The coefficient of variation of the method was lower than 5%. The sensitivity of the GC-FID was very similar to what of mass spectrometer detector (GC-MSD, HP 5970 A).

Acetone↗
PubMed1987

The urinary concentration of solvents as a biological indicator of exposure: proposal for the biological equivalent exposure limit for nine solvents.

Organic solvents are generally volatile substances that are absorbed mainly through the lungs; they are eliminated chiefly through the lungs and kidneys. In urine they are present as metabolites and, in very little part, as parent compound. The urinary concentration of solvent (Cu) can be used for the biological monitoring of exposed subjects to evaluate their exposure and correlate with the Threshold Limit Value (TLV) during the working day. The authors report some results obtained with workers occupationally exposed to solvents. The results concern the correlation between urinary concentration (Cu, micrograms/L) vs. average environmental concentration (Ci, mg/m3) measured in the breathing zone. For each solvent studied (acetone, 2-cyclohexane, 1,2-dichloropropane, n-hexane, methyl ethyl ketone, perchloroethylene, styrene, toluene, 1,1,1-trichloroethane) the authors propose a Biological Equivalent Exposure Limit (BEEL) corresponding to the environmental TLV.

Air Pollutants, Occupational↗
PubMed1986

Urinary elimination of acetone in experimental and occupational exposure.

Fifteen volunteers were exposed to an acetone vapor concentration of 964-8, 610 mumol/m3 (56-500 mg/m3) for 2-4 h in an exposure chamber. Ten subjects were at rest during the exposure, and five were exposed at alternate rest and light physical exercise. Subsequently 104 workers occupationally exposed to acetone were studied. The relative uptake averaged about 53%, and the ratio of the alveolar concentration to the environmental concentration averaged about 0.28. Both for the experimentally exposed subjects and the occupationally exposed workers the urinary acetone concentration showed a linear relationship to the corresponding environmental time-weighted average concentration. A linear equation also existed between urinary concentrations and the amounts of acetone absorbed. The findings enable a consideration of the urinary concentration of the unaltered acetone as an appropriate exposure indicator and the proposal of a "biological equivalent threshold" to be used in the field of biological monitoring.

Acetone↗
PubMed1985

Urine/air partition coefficients for some industrially important substances.

The urine/air and blood/urine partition coefficients (lambda) of 43 commonly employed organic solvents (Aliphatic, Cyclic, Aromatic and Halogenated Hydrocarbons, Ketones, Alcohols and Esters) are reported. The analyses were performed by the multiple equilibration method (constant pressure method) using a Hewlett-Packard 5880 gas chromatograph. The lambda values proposed can be employed in the field of biological monitoring of subjects occupationally exposed to solvents vapors.

Air Pollutants, Occupational↗
PubMed1979

[Determination of plasma chromium in pregnant women at term and in the umbilical cord blood].

Plasma chrome concentrations were determined in pregnant women, in the funiculus blood of their children and in a population of a children within the first year age. Plasma chrome concentrations tend to significantly decrease during pregnancy, pointing out the effect of pregnancy on chrome metabolism. No significant variations were found in plasma chrome values both of mother blood and foetus blood. In newborn babies, plasma chrome concentrations tend to significantly increase within the first year of age.

Adult↗
PubMed1975

[Measurement of "flow-volume" curves and "closing volume" in occupational medicine. Normal findings in healthy subjects (author's transl)].

A method is described for measuring, by a single test, some functional respiratory indexes, such as lung volumes, dynamic tests (flow-volume curve included), rapid He and CO2 curves, "closing volume". The normal values of "closing volume" and of forced expiratory flows obtained in 114 healthy subjects (65 men and 49 women) are then reported. Such values are comparable to those obtained by other authors. An equipment is used by the authors which is easily transportable to the workplace; their method can therefore be used for surveys of workers exposed to occupational respiratory risk during a working shift. The described respiratory index should be able to detect in a pre-clinical stage the early functional changes in chronic bronchitis.

Adult↗