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Biomedical subjects

C Colosio

Publications and source records attributed to C Colosio.

8 recordsLinked to original sources
PubMed1998

Albumin and hemoglobin adducts as biomarkers of exposure to styrene in fiberglass-reinforced-plastics workers.

OBJECTIVE: The purpose of this work was to compare levels of styrene-7,8-oxide (SO) adducts of albumin (Alb) and hemoglobin (Hb) with those of two urinary metabolites of styrene, mandelic acid (MA) and phenylglyoxylic acid (PGA), among workers exposed to styrene in the reinforced-plastics industry and in unexposed subjects. We also wished to determine whether cigarette smoking influenced adduct levels among these subjects. METHODS: A group of 22 male workers was selected on basis of an expectedly high level of exposure to styrene, and a group of 15 controls was selected from hospital blood donors and hospital staff. In the exposed group, MA and PGA were quantified by high-performance liquid chromatography (HPLC) analysis of urine samples collected prior to the work shift. The SO adducts were cleaved from cysteine residues by reaction with Raney nickel to give 1-phenylethanol (1-PE) and 2-phenylethanol (2-PE), which, after derivatization, were measured using gas chromatography-mass spectrometry (GC-MS) in the negative-chemical-ionization (NCI) mode. RESULTS: The estimated mean levels of MA and MA + PGA were 74 and 159 mg/g creatinine, respectively. Using the levels of urinary metabolites, an average styrene concentration of about 100 mg/m3 in the workplace air was estimated. The mean levels of 2-PE and 1-PE adducts in exposed workers were 2.84 and 0.60 nmol/g Alb and 5.44 and 0.43 nmol/g Hb, respectively. When subjects were stratified by level of urinary metabolites [zero (controls), low-level exposure (MA + PGA < or = 159 mg/g creatinine), and high-level exposure (MA + PGA > 159 mg/g creatinine)] and smoking status (smokers versus nonsmokers), a difference in Alb adduct levels was found among the groups (2-PE P = 0.002, I-PE P = 0.052). The difference in 2-PE-Alb levels was related to exposure category, to smoking status, and to their interaction. Correlations at or near a 0.05 level of significance were observed among the workers (n = 22) between individual levels of SO-protein adducts and MA + PGA (2-PE Alb, r = 0.54, 2-PE Hb, r = 0.40). CONCLUSION: Our data suggest that only exposure to relatively high levels of styrene allows a clear relationship to be detected between styrene exposure and SO adducts, due in part to the effects of cigarette consumption and to the high background levels of these adducts observed in unexposed subjects.

Adult↗
PubMed1991

Occupational triphenyltin acetate poisoning: a case report.

A case of triphenyltin acetate (TPTA) poisoning is described. The patient, who had been exposed mainly to cutaneous absorption, showed acute stages of an urticarial eruption, signs of hepatic injury, slight glucose intolerance, and electroencephalographic abnormalities. Concomitant with the highest concentrations of tin in plasma and the peak of tin excretion in urine, neutrophils did not show the normal increase in actin polymerisation after stimulation with a chemotactic peptide (100 nM fMLP). The peak of urinary excretion of tin occurred between the fifth and the sixth day after poisoning; subsequently, the rate of excretion became slow, suggesting biphasic kinetics with the possibility of a cumulative trend.

Adult↗
PubMedDate not supplied

Toxicological and immune findings in workers exposed to pentachlorophenol (PCP).

Pentachlorophenol (PCP) is a pesticide used worldwide in industrial and domestic applications. Data available on the effects of technical-grade PCP on the immune system are insufficient and equivocal; some data indicate inhibitory effects, whereas others suggest stimulating effects. This study was performed to evaluate toxicological and immune findings in 32 subjects who had prolonged exposure to PCP in a wood factory and in 37 controls. PCP concentrations were determined in plasma and urine of all subjects. Lymphocyte subsets of CD3-, CD4-, and CD8-positive cells were evaluated, and the proliferative response of peripheral blood mononuclear cells (PBM) to mitogens was assessed. The results suggested the absence of major laboratory and clinical signs of PCP-dependent immune deficiency. A weak effect of long-term exposure to PCP on the functional immune response could not be ruled out because of the finding of a decreased response to 5% PHA in the high-exposure group. A weak effect against hepatocyte membrane was evidenced by the finding of raised serum concentration of glycocholic, taurodeoxycholic, and glycochenodeoxycholic acids in subjects directly exposed to PCP for more than 10 y.

Adolescent↗
PubMedDate not supplied

Immunomodulatory effects of occupational exposure to mancozeb.

The effects of occupational exposure to ethylene-bis-dithiocarbamate of manganese and zinc on the immune system were evaluated in a group of mancozeb-exposed manufacturers and controls. The immune system tests revealed the following: (a) lymphocyte proliferative responses triggered by different activators and mitogen-induced IL-2 production were higher in exposed subjects than in controls; (b) production of monocyte/macrophage-derived IL-1 and polyclonal IgG and IgM, by beta-lymphocytes, did not differ between exposed subjects and controls; (c) percentages and absolute numbers of total T-cells, T-helper cells, T-suppressor/cytotoxic cells, activated T-cells, total beta-cells, and natural killer cells were similar in exposed subjects and controls; (d) serum immunoglobulin classes and complement fractions were within the range of normality; and (e) rheumatoid factor and non-organ-specific serum autoantibodies were absent in exposed and control subjects. An increase in T-cell functional response was found in the exposed group, suggesting a slight immunomodulator effect of mancozeb in conditions of low-level, prolonged occupational exposure.

Air Pollutants, Occupational↗
PubMedDate not supplied

[Immunotoxicology in occupational and environmental medicine: prospectives, limitations, and research objectives].

The immune system is able to recognize and neutralize potentially harmful agents, conferring to the organism resistance to infectious and malignant diseases. The authors have reviewed the literature and identified a group of substances able to enhance and/or reduce different immune functions, both in an experimental model and in occupational and environmental human exposure. The group includes several polyhalogenated hydrocarbons, particularly polychlorinated biphenyls, polybrominated biphenyls, tetrachloro-dibenzo-p-dioxin (TCDD), some metals like lead, cadmium and mercury, pesticides, i.e. dithiocarbamates and organotin compounds, organic solvents. The observed changes are usually slight and do not allow prognostic conclusion. In this study, the authors propose a 3-level rank of tests suitable for the immune evaluation of individuals occupationally exposed to xenobiotics, divided into three levels, as follows: tier 1: immunoglobulin classes (IgG, IgA, IgM), complement fractions (C3, C4), rheumatoid factor, and non-organ specific autoantibodies (AMA, SMA, ANA); CD3, CD4, CD8, CD57, CD20, HLA-DR; CD3/HLA-DR positive lymphocyte subsets; tier 2: determination of the mitotic response of peripheral blood lymphocytes to phytohaemoagglutinin, anti-CD3 monoclonal antibody, phorbol-myristate-acetate (PMA) and polyclonal immunoglobulin production after stimulation with pokeweed mitogen; tier 3: cytokine production with and without mitogen stimulation. The approach is "step by step" and assumes the need of a closely integrated and comparative evaluation of the findings obtained. The protocol could be used in research fields; moreover, some of the tests could be useful in the monitoring of persons exposed in the environment or in the workplace to immunotoxic substances or to biological agents.

Animals↗