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Biomedical subjects

L Soleo

Publications and source records attributed to L Soleo.

At least 37 records · Page 2Linked to original sources
PubMed1993

Blood concentrations of carbon disulphide in dithiocarbamate exposure and in the general population.

Blood carbon disulphide (CS2), both free and total, was determined by gas chromatography-mass spectrometry in 112 "normal" subjects and in 20 subjects employed in a dithiocarbamate factory, comprising ten blue-collar workers involved in dithiocarbamate production and ten white-collar office staff. The ten production workers were examined over two workshifts, the first at the beginning of the week (Monday) and the second after an intervening period of at least 1 day. Three blood samples were taken for each shift studied, one prior to starting work, one at the end of the shift and the third 16 h after the end of the shift (on the following morning). The mean CS2 blood levels measured in the 112 normal subjects was 663 ng/l for the free fraction and 3178 ng/l for the total. In 16 blood samples taken from the ten dithiocarbamate factory office workers, the mean free and total CS2 blood levels were 846 and 4140 ng/l, respectively, i.e. not significantly different from those observed in the normal subjects. At the end of the first 8-h shift, the ten dithiocarbamate factory production workers had free and total CS2 values of 1070 and 8471 ng/l, respectively, which were significantly higher than those observed prior to starting work (240 and 4738 ng/l). All the total CS2 levels measured in the shop-floor workers, with the sole exception of the values recorded prior to the start of the Monday shift (4738 ng/l), ranged from 7047 to 8471 ng/l and were significantly higher than those measured in the white-collar staff (4140 ng/l).

Adult↗
PubMed1990

Effects of low exposure to inorganic mercury on psychological performance.

The effects of low exposure to inorganic mercury on psychological performance was investigated: the study groups included eight chronically exposed workers and 20 who were only occasionally exposed. These were compared with a control group of 22 subjects from the same plant who were not exposed to mercury. All subjects were administered the WHO test battery to detect preclinical signs of central nervous system impairment: the battery includes the Santa Ana (Helsinki version) test, simple reaction time, the Benton test, and the Wechsler digit span and digit symbol. In addition, the Gordon test was used to study personality profiles and the clinical depression questionnaire. Urinary mercury was used as indicator for internal dose. To this effect, urinary mercury observed in workers examined from 1979 to 1987 was evaluated. Of the pyschic functions explored by behavioural tests, only short term auditory memory was found to be impaired in the chronically exposed workers (p less than 0.05 compared with the controls). The chronically exposed workers were also found to be more depressed than those in the two other groups. No changes of visual motor functions were observed. The personality of the occupationally exposed workers was found to be considerably changed compared with that of the control group. On the basis of the results obtained and in view of urinary mercury mean concentrations in the exposed group which were 30-40 micrograms/l over the years, it is suggested that the TLV-TWA for mercury should be lowered to 0.025 mg/m3 and that the biological urinary exposure indicator for biological monitoring should be 25 micrograms/l.

Adult↗
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

Reversibility of thymulin production impairment by L-arginine supplementation in mice exposed to inorganic mercury.

Immunotoxicological effects fo mercury on peripheral immune system are known. We had previously in vitro found that mercuric chloride inhibits thymulin production in mouse thymus cultures at concentrations as low as 10(-8) M. In this study, thymus efficiency, assessed as production of active and total thymulin, was evaluated in vivo using young mice that were injected sc every 3 days for 4 weeks with saline containing mercuric chloride at different concentrations (0 -controls-, 0.001 or 1.0 mg HgCl2/kg body weight). The results show that both the doses are able to cause a significant reduction in active and total thymulin production. Since arginine enhances immune efficiency some of the animals also received a diet supplemented with arginine in order to evaluate a possible role of arginine during mercury intoxication. The data show that arginine has a protective effect on thymic endocrine efficiency. Mice, treated with the lowest dose of mercury and receiving and arginine supplemented diet, produced active and total thymulin like mercury untreated mice. Arginine is an aminoacid which may be found in various amounts in different foods, some foods are particularly rich in arginine i.e. peanuts, stock fish. We suggest that the daily arginine intake may account for individual susceptibility to the mercury-induced immunological effects which are found in mercury occupationally exposed workers.

Animals↗
PubMedDate not supplied

[Xenobiotics and glutathione].

Mercapturic acids (MA) are the final step in the biotransformation of compounds deriving from conjugation of electrophiles to glutathione (GSH). GSH is an important endogenous tripeptide (g glutamyl-cysteinil-glycine) present in mammalians essentially in erythrocytes, liver and kidney. It is involved in several intracellular detoxification routes. Among these routes, the conjugation with electrophiles, usually epoxides of aromatic and aliphatic organic compounds, avoids the formation of covalent bounds between alkylating compounds and cellular macromolecules (DNA, RNA, proteins) and prevents their mutagenic and cancerogenic effects. The conjugation of electrophiles to GSH can proceed spontaneously or catalysed by GSH-S-transferase (GST). Cytosolic isoenzymes GST-T1 and GST-M1 show a genetic polymorphism in rats and humans, which determines the individual hypersusceptibility to the toxic effects of xenobiotics and the variability in the formation of MA. GSH-S-conjugates are biotransformed to their corresponding MA through several steps, involving the removal of the glutamic acid and then of the glycine. Finally, the residual cystein-S-conjugate is acetylated by a genetically polymorphic acetyltransferase to form a N-acetyl-cystein-S-conjugate or mercapturic acid. The MA metabolic pathway is a process that involves several organs, particularly the liver, the kidney and the small intestine. The intensity of the metabolic processes of these routes in the various organs is strongly dependent of the activities of the involved enzymes and it is different in the various species. As shown by several studies in the last fifteen years, the formation of MA takes place in humans too. Therefore the importance of their use in biological monitoring as internal dose indicators of occupational and environmental exposure to electrophiles appears undoubted.

Animals↗
PubMedDate not supplied

[Fatiguing work, aging and health: a cross-sectional study of a group of anesthesiologists].

A cross-sectional study was carried out to verify if work as an anaesthetician-reanimator can be considered as a fatiguing job. An anonymous self-administered questionnaire was utilized to obtain information about the general characteristics of the subjects, job organization, human relations, perceived risks and previous diseases; 1438 questionnaires were examined. The results of the study showed that in anaesthetist-reanimator: organic diseases do not occur earlier than expected; perception of the emotional aspects related to the particular occupation is low; the group relationships are difficult, on both horizontal and vertical levels, and these difficulties increase work-stress and hinder its management; age influences the occurrence of both arthritic and stress-related diseases; there is an association between jobs dissatisfaction and stress disorders; all the causal variables considered, evaluated as a group, constitute a heavy physical load, that leads to risk of stress related diseases.

Age Factors↗
PubMedDate not supplied

[Renal effects of low doses of mercury].

OBJECTIVES: The present study was aimed at investigating early markers of renal damage and dysfunction in subjects exposed to low doses of mercury from different sources. Different groups of subjects were examined with urinary Hg excretion (HgU) ranging from 0.1 to 35.0 micrograms/g creatinine: 122 occupationally exposed workers, 22 subjects living in a non-polluted area, but consuming large amounts of tuna and sword fish, and 197 controls. METHODS: Several markers of renal changes were measured in urine (albumin, fibronectin, beta 2-microglobulin, retinol-binding protein, tubular antigens, N-acetyl-beta-D-glucosaminidase activity) and serum (beta 2-microglobulin and cystatin C). Serum autoantibodies towards collagen, laminin and tubular antigens were assessed in subjects with abnormal renal markers. The role of glutathione-S-tranferases GSTT1 and GSTM1 polymorphisms in the inter-individual variability of biological response to Hg was also investigated. RESULTS: Renal markers were not correlated with HgU. None of such markers differed significantly between exposed workers and controls, except for urinary beta 2-microglobulin, which was decreased in Hg-exposed workers (GM = 55.8 vs 86.6 micrograms/g creatinine), in the absence of any changes in serum concentration. Subjects usually eating tuna and sword fish showed an increased urinary excretion of beta 2-microglobulin, albumin and fibronectin. Serum titres of auto-antibodies did not differ between the groups. Neither in controls nor in exposed workers were the observed differences modified by the GSTM1 and GSTT1 genotypes. CONCLUSION: The present study did not provide evidence of any changes in kidney integrity and function in subjects exposed to very low levels of inorganic Hg resulting in urinary Hg lower than 35 micrograms/g creatinine. Nor did we obtain evidence of Hg-induced autoimmunity towards kidney components. The potential modifying role of GST polymorphisms could not be clarified in the absence of effects associated with exposure to the risk factor, i.e., to inorganic Hg. Preliminary data suggesting nephrotoxic effects of organic Hg from a diet rich in large fish resulting in increased levels of both blood and urinary Hg--which however did not exceed 20 micrograms/g creatinine--deserves further investigation.

Adult↗
PubMedDate not supplied

[Immunologic effects of exposure to low levels of inorganic mercury].

OBJECTIVE: The immune system is a target for the toxic effects of inorganic mercury, both in humans and animals. In humans it has been observed that occupational and environmental exposure to inorganic mercury may cause both clinical (autoimmunity, hypersensitivity) and subclinical effects (cellular and humoral immunologic variable modifications). To obtain a better definition of these effects with respect to the exposure levels, a multicentre study was performed on 117 workers exposed to very low doses of inorganic mercury and 172 subjects from the general population of the same geographical area with environmental exposure to mercury from dental amalgams and dietary fish intake. RESULTS: The white blood cell count was included in the normality range for all subjects and there was no difference between exposed and non exposed subjects. The immunologic variables studied showed an increase of the CD4+ and CD8+ number in exposed workers compared to non-exposed subjects, with a statistically significance only for CD4+, while no difference was observed regarding CD4+, CD8+, NK+ percentage and CD4+/CD8+ ratio. A significative decrease of serum IL-8 and an inverse correlation between serum levels of this cytokine and HgU were observed in exposed workers compared to non exposed subjects. No association between immunologic variables and both dental amalgams and dietary fish intake was found in subjects not occupationally exposed to inorganic mercury. DISCUSSION: The decrease in IL-8 serum levels observed in exposed workers might suggest an immunosuppressive effect of occupational exposure to very low doses of inorganic mercury. This result suggests the need to revise of current HgU BEI after further definition of its prognostic significance.

Adult↗
PubMedDate not supplied

[Adaptation of the TriTEST TM for the investigation of blood samples for a multicenter study taken to a single laboratory].

BACKGROUND: Immunotoxicological studies in humans are usually carried out via the determination of some selected immune parameters in subjects occupationally and/or environmentally exposed to immunotoxic substance. One of the most often measured parameters is the determination of lymphocyte subsets, which needs to be carried out in a very short time (a few hours) after blood collection. This is the major problem limiting the determination of lymphocyte subpopulations in field studies, where samples are usually collected directly at the workplace, and very often at the end of the workshift. Unfortunately, these collection modalities significantly prolong the time between collection and analysis. The problem is more evident in multicentric studies, where a further problem is represented by the time needed to send samples to the laboratory. OBJECTIVE: Since an immune evaluation was planned, including the determination of lymphocyte subpopulations CD4 (T-helper), CD8 (T-suppressor cytotoxic) and CD16/CD56 (natural killer) in the project "Assessing health effects in man from exposure to low doses of inorganic mercury in environmental and occupational settings", a method was developed for performing cytofluorimetric analysis in "field studies". METHODS: The method is based on commercially-available kits, and involves in loco treatment. Whole blood is labeled with monoclonal antibodies, and fixed samples immediately after collection. After the treatment, the samples are ready for flow cytometric analysis, which may be performed after a two-day period from sample collection. RESULTS AND CONCLUSION: The method described is adequate for immunotoxicity testing in field studies because it prolongs the maximum latency time from collection and cytofluorimetric analysis up to 48 hours. A second interesting characteristic of the method is the possibility of using whole blood, without any need of either complex manipulations or particular equipment.

Antibodies, Monoclonal↗
PubMedDate not supplied

[Evaluation of the neurotoxic and nephrotoxic effects following long-term exposure to metallic mercury in employed at a chlorine/sodium-hydroxide plant].

OBJECTIVES: Within the frame work of a wide multicentre study, a sub-study was developed in order to explore the occurrence of early effects on the central nervous system, on the kidney and on the neuro-immune system in the workers of a chloro-alkali production plant exposed to metallic mercury at airborne concentration levels lower than 0.025 mg/m3 (TLV-TWA). They were compared to a control population of employees of the same huge petrochemical plant with different job that did not implicate exposure to mercury vapors. Specifically, the study aimed at revealing the occurrence of early effects on the central nervous system related with mercury exposure, as can be assessed through neurophysiological and neurobehavioral tests. METHODS: The excretion of urinary mercury was measured by atomic absorption spectrometry. The study of renal function was assessed by measurement of the urinary excretion of some high and low molecular weight protein markers (albumin, beta 2-microglobulin, retinol-binding protein, fibronectin, specific proximal tubule brush border antigens, N-acetyl-beta-D-glucosaminidase). The neurobehavioral status of the study subjects was assessed by means of several test parameters (Simple Reaction Time, Color Word Vigilance Test, Symbol Digit, Finger Tapping, Mood Scale of Kjellberg and Iwanowski, Subjective symptoms questionnaire (QSS), Luria Nebraska Motor Scale, Branches Alternate Movement Task and Tremometry). RESULTS: The values of urinary excretion averaged 12 +/- 8 micrograms Hg/g of creatinine for the exposed workers group (n = 38), while for the reference group (n = 34 cases) urinary excretion was statistically lower, averaging 4 +/- 6 micrograms Hg/g of creatinine. Neither the parameters selected for the assessment of renal functions, nor those chosen to probe the neurobehavioral status of the probands revealed statistically reliable differences between the group of exposed workers (length of exposure: range 1-34 years) and the control group. Nevertheless, some minor but still statistically reliable correlations were found between some neurobehavioral parameters and some demographic variables describing the whole group of tested workers, but not to the level of occupational exposure to mercury. CONCLUSIONS: The results of the study confirm the lack of toxic effects of clinical importance on the central nervous system and on the kidney for values of mercury urinary excretion lower than the suggested index of biological exposure (IBE) of 35 micrograms Hg/gram of creatinine.

Adult↗
PubMedDate not supplied

[Reference values of urinary mercury in the Italian population].

This paper shows the results of a polycentric study performed to assess the reference values of urinary mercury (U-Hg) in Italian population. 374 subjects from four Italian cities (Bari, Brescia, Genova e Siena) have been examined. A questionnaire on life style, dietary habits, occupational or environmental exposure to Hg and clinical history has been administered to every participant and number and surface of dental amalgams have been verified for all subjects. The determination of U-Hg has been performed on urinary extemporary samples by hydride generation atomic absorption method (HG-AAS); urinary creatinine has been determinated to reduce the intraindividual variability. U-Hg reference values were: 0.21-3.20 micrograms/g creat (5 degrees and 95 degrees percentile) and 0.12-6.04 micrograms/g creat (range). Moreover study results have shown that number and surface of dental amalgams, dietary fish intake and body mass index (BMI) influenced significatively U-Hg excretion. U-Hg reference values from this polycentric study resulted comparable to those assessed in other European countries, whereas the mean U-Hg observed in the referent Italian population was lower.

Adolescent↗
PubMedDate not supplied

[Role of genetic polymorphism in risk assessment].

Genetic polymorphism is an important factor of individual susceptibility to drugs or to toxic substances in environmental and occupational exposure. Although polymorphism is never the only responsible of a disease, it can modify both the level of risk for adverse effects and the levels of biomarkers after exposure to some toxic agents. In this paper two important groups of polymorphic enzymes, responsible of the detoxification of exogenous substances, were examined: paraoxonase-1, involved in the metabolism of some organophosphorus insecticides, and glutathione S-transferases, involved in the detoxification of numerous epoxide metabolites. Particularly the role of GSTT1 and GSTM1 polymorphism on the biological indicators of 1,3-butadiene has been evaluated. Moreover, the influence of delta-aminolevulinic acid dehydratase, enzyme involved in the sinthesys of the eme, on the biological indicators of exposure and effect to lead has been also examined.

Aryldialkylphosphatase↗
PubMedDate not supplied

[Implementation of parliamentary act D. Lgs 25/02 and definition of "moderate risk"].

This paper describes the position of the Joint Working Group of the Italian Association of Industrial Hygienists (AIDII), the Italian Society of Occupational Health and Industrial Hygiene (SIMLII) and the Italian Society of Toxicology (SITOX) on "Analysis of Parliamentary Act D.Lgs 25/02 and role of the Scientific Societies in the definition of Limit Values". The positive aspects of the new law which implements the European Directive 98/24 are discussed, including the abolition of the rigid periodicity of medical examinations as stated by the old rule D.P.R. 303/56. The Authors also address various parts of the law which appear to be unclear and controversial and highlight the expected difficulties arising for the employers and the safety and health professionals during the application of this new piece of legislation. Moreover, a number of discrepancies are noted between the new Italian law and the original Directive or other current Italian rules such as i. the translation of the term "slight risk", as from the original Directive, into "moderate risk", and the resulting non compulsoriness of health surveillance and biological monitoring of the workers in presence of a "moderate risk", ii. the concurrent exclusion, under the same circumstances, of the occupational physician from risk assessment procedures and iii. the upward modification of the previously established (D.Lgs 277/91) occupational exposure limits for lead. Moreover, the Authors examine and criticize--both in semantic and in toxicological terms--a recent proposal for the definition of "moderate risk" made by an ad hoc Consulting Committee of the Labour Ministry, in which the term "moderate" has been interpreted either as "low" or as "irrelevant for health effects", clearly two very different meanings. Besides, it would be inappropriate to define the conditions of a moderate risk based only on the level of exposure to the chemical (expressed as a fraction of the corresponding limit value), without considering the two other components of risk assessment for that chemical (hazard and susceptibility). Even worse would be the use of simplified models based on "algorithms", which might be useful in a preliminary phase of risk assessment, but easily could lead to an under- or over-estimation of risk, particularly when used by non professionals. In conclusion, the Working Group recommend that the new law be amended in order to clarify its most controversial aspects, whose misinterpretation could severely jeopardize the protection of the workers' safety and health at work.

Humans↗