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Biomedical subjects

A Aitio

Publications and source records attributed to A Aitio.

At least 73 records · Page 4Linked to original sources
PubMed1984

Tumor markers and neurological signs in asbestosis patients.

Ninety asbestosis patients were examined clinically with special emphasis on the function of the peripheral and the central nervous system. Serum specimens were analyzed for carcinoembryonic antigen(s) (CEA), ferritin, and beta 2-microglobulin (beta 2m) content. The patients were classified into four subgroups: (1) those with peripheral neuropathy, (2) those with involvement of central nervous system, (3) those with both types of neurological signs, and (4) those with normal neurological status. The levels of serum CEA, ferritin, and beta 2m were elevated in all four subgroups. No statistically significant differences were found between the groups in the prevalence of elevated values of the three tumor markers (equal or above the following limits: CEA, 5 micrograms/liter; ferritin, 400 micrograms/liter, and beta 2m, 3 mg/liter). The patients currently smoking had a higher level of serum CEA than nonsmokers or exsmokers, but the differences were not statistically significant. In the subgroup that comprised those asbestosis patients in whom the disease could be considered progressive according to the ILO 1980 classification of the chest radiographs, the mean level of CEA in serum was higher than that of the patient group without such progression of the disease (p less than 0.05, Student's t test). Although the prevalence of abnormal neurological signs was high in these asbestosis patients, no obvious correlation was found between the neurological findings and the tumor markers studied.

Adult↗
PubMed1984

Urinary excretion of chromium as an indicator of exposure to trivalent chromium sulphate in leather tanning.

Two workers exposed to trivalent chromium sulphate in a leather tannery had high concentrations of chromium in the urine. The concentration of chromium showed a workshift-related diurnal fluctuation, but it was remarkably high even after a vacation, indicating accumulation of chromium in the body. The concentrations of chromium in the workplace air, as collected on filters using standard techniques, were below 30 micrograms/m3. The chromium in the air was present in the form of large droplets not collected by the standard techniques. In the blood stream, chromium was transported exclusively in the plasma. No absorption of chromium through the skin could be detected. Absorption from the gastrointestinal tract was calculated to explain the findings.

Adult↗
PubMed1984

Metabolism and urinary excretion of mutagenic metabolites of benzo[a]pyrene in C57 and DBA mice strains.

Groups of C57Bl/6 (B6) mice (responsive) and DBA/2 (D2) (non-responsive) mice received an i.p. dose of benzo[a]pyrene (BP) (100 mg/kg body weight) with or without pretreatment with beta-naphthoflavone (BNF), an inducer of monooxygenases. The amount of mutagenic BP metabolites in the urine was determined by the Salmonella/microsome assay (strain TA100) and excretion of BP metabolites was quantified by h.p.l.c. After inducer treatment, the responsive mice excreted more mutagens and total oxidized BP metabolites in the urine than did the non-responsive strain. The ratio of BP diols:total oxidized metabolites was 0.42 in B6 mice and 0.72 in D2 mice and was not affected by inducer treatment. After a dose of [14C]BP, radioactivity was measured in the faeces for up to 7 days. The half-life of [14C]BP in the non-responsive D2 mice was about twice that in the responsive B6 mice. Our results agreed with a previously proposed model of the risk factors for toxic effects and/or the development of tumours after exposure to polycyclic aromatic hydrocarbons in responsive and non-responsive mouse strains.

Animals↗
PubMed1984

Skin absorption as a source of error in biological monitoring.

Concentrations of toluene, tetrachloroethylene, and 1,1,1-trichloroethane were determined in blood collected from both forearms of subjects after one of their hands was soaked for 5 min in the corresponding solvent or in a thinner containing toluene, as a simulation of the washing of hands with solvent after work. The concentrations of toluene, tetrachloroethylene, and 1,1,1-trichloroethane on the soaked side were high, maximally 5.4, 9.0, and 4.0 mumol/l, respectively, and 20-, 130-, and 35-fold, respectively, compared to the contralateral side. Intraindividual differences were very marked, and dramatic changes were detected within a short period of time. It was not until after 3 h with toluene and 5 h with the chlorinated solvents that the difference between the two arms vanished. It is concluded that analyses of solvents in blood specimens drawn during or immediately after the workday may lead to markedly erroneous estimations of exposure.

Environmental Exposure↗
PubMed1984

Styrene exposure and the liver.

The liver functions, as reflected by the serum enzyme activities of aspartate aminotranferase, alanine aminotransferase, and gamma glutamyl transferase and by the concentrations of cholic acid and deoxycholic acid, of 34 styrene-exposed and 34 reference female workers were followed prospectively for a year. The mean age of exposed workers was 34.2 years, mean duration of past exposure 5.1 years. The mean age of the referents was 30.7 years. During the follow-up period blood samples were collected three times for the determinations. The history of possible liver disease and alcohol consumption was ascertained by questionnaire. Altogether 87 samples of both groups were analyzed. The styrene-exposed group did not have higher values for any measurement when compared with those of the referents. Two persons in both groups had one sample with transaminase activities exceeding laboratory reference values. The abnormal values were associated with the use of drugs or alcohol. Cholic acid and chenodeoxycholic acid concentrations were of the same magnitude in both groups.

Adult↗
PubMed1984

Biological monitoring of occupational exposure to nickel.

Biological monitoring and hygienic monitoring complement each other in assessing occupational exposure to nickel. Biological monitoring is mainly directed to following the exposure of individual workers. In order to estimate exposure from data on biological monitoring, the exposing agent, i.e., the chemical species of nickel involved must be known. Comparisons between exposures are most reliable when made under similar exposure conditions. In particular, when urine is monitored, contamination of the sample from the dust in the air, workers' clothes, and hands, is a major problem. The sampling time must be standardized. At present, no clear-cut preference can be given to plasma rather than urine or vice versa. With the exception of nickel carbonyl poisoning, no health risk estimation can be performed based on the results of biological monitoring. Cytogenetic methods do not seem appropriate for assessing risk or exposure. The increase in chromosome gaps reported in one study seems to indicate the need for further research.

Adult↗
PubMed1984

Biological monitoring of workers exposed to polychlorinated biphenyl compounds in capacitor accidents.

For biological monitoring of workers exposed to polychlorinated biphenyl (PCB) compounds, a gas-chromatographic method for analysis of PCBs in serum was developed. The quantitation is performed with 15 pure isomers, and extraction and concentration factors are corrected with the aid of asymmetric PCB compounds added to each specimen. By this method, humans with no known occupational exposure to PCB compounds showed PCB levels in serum that were always less than 3 micrograms/l. Workers exposed in capacitor accidents have shown maximal concentrations close to 50 micrograms/l.

Accidents, Occupational↗
PubMed1984

Kinetic considerations in monitoring exposure to chemicals.

The aim of biological exposure monitoring is to estimate the amount of the chemical absorbed in the body of each individual worker. As the concentration of any foreign chemical in body fluids is not constant, but shows an exposure-related fluctuation, this estimation may be successful only when based on knowledge of the behaviour of the chemical in the body, i.e., its kinetics. Skin absorption is one of the reasons for performing biological monitoring of exposure. However, when the absorbed chemical is being monitored in the blood, skin absorption may be a source of considerable error since the concentration of the chemical in the blood specimen collected from the cubital vein does not represent the whole body but only the arm. It should be borne in mind that the errors caused by kinetic variations are similar, independent of the type of measurement performed; thus, they pertain equally to the measurements of chemicals by traditional chemical analytical means and to measurements of the character of the chemical, e.g., mutagenicity.

Animals↗
PubMed1983

Effect of occupational mercury exposure on plasma lysosomal hydrolases.

The activities of three plasma lysosomal hydrolases, beta-galactosidase, beta-glucuronidase and beta-N-acetylglucosaminidase, were studied in 20 workers exposed to metallic mercury vapor in a chlorine alkali plant and in 10 nonexposed referents. The urinary excretion and blood levels of mercury were determined on the day of study, and the history of mercury exposure was reviewed from the records of mercury concentrations in urine and blood over periods of up to 133 months. The average levels of beta-N-acetylglucosaminidase and beta-glucuronidase were higher in the plasma of exposed workers, but the difference was not significant. No significant positive correlation was seen between lyosomal enzyme activities and cumulative long-term exposure to mercury. It is concluded that measurement of plasma lysosomal hydrolase-activities is not of great value in the biological monitoring of workers exposed to low concentrations of metallic mercury vapor. In line with published data, the concentration of mercury showed a clear-cut diurnal variation in nonexposed persons, persons currently exposed and persons with a history of past exposure. The excretion rate of mercury remained constant throughout the day.

Acetylglucosaminidase↗
PubMed1983

Exceptional pharmacokinetics of trivalent chromium during occupational exposure to chromium lignosulfonate dust.

The excretion of chromium in the urine of workers exposed to chromium lignosulfonate was studied. The chromium in the dust was in the trivalent (III) oxidation state, and 30% of the particles were less than 5 micron in diameter. Chromium (III) lignosulfonate dust was rapidly absorbed, and a peak of urinary excretion was seen immediately after exposure. No appreciable accumulation of chromium occurred over 3 d, as evaluated by comparison with preshift urinary chromium concentrations. The addition of ethylenediaminetetra-acetate to the urine of exposed persons greatly enhanced the capacity of chromium to traverse a dialysis membrane; the same effect was seen with chromium (III) chloride. It is concluded that chromium (III) lignosulfonate yields chromium (III), which acts pharmacokinetically like water-soluble hexavalent chromium compounds.

Absorption↗
PubMed1982

Exposure limits and medical surveillance in occupational health.

The standards for pollutants in workplace air constitute a social consensus or agreement about acceptable levels of occupational hygiene. This agreement to exposures up to these limits inevitably includes a finite risk to the health of the workers. The numeric values of standards are needed to assess the requirements for ventilation and other occupational hygiene conditions. Planning and everyday practice in industry also need hygienic standards so that practical hygienic and safety measures can be maintained. These standards are not, however, levels below which there is no risk to health. While the hygienic standard itself carries acceptance of a certain risk, doctors cannot ethically accept any health risk to workers whatever the source of exposure. Thus personnel working in occupational health have to think about the risks of ill health even when the hygienic standards are met. The physician in occupational health has to be especially concerned to discover and estimate the risks to anyone particularly susceptible to exposures within the hygienically acceptable conditions. To do this, the occupational health physician uses medical examinations and specific investigations. In the follow-up of workers, health occupational health personnel use medical examinations in order to detect possible risks or to assess the general health status of individual workers. Health examinations are also used to detect specific injuries caused by the agents to which workers are known to be exposed in their work.

Carcinogens↗
PubMed1982

Tissue concentrations and interaction of zinc with lead toxicity in rabbits.

Adult male rabbits were exposed to lead (0.2%), zinc (0.5%) or to both lead and zinc (0.2% and 0.5%) which were given in the drinking water as acetates for 2 weeks or 4 weeks. Blood lead levels in lead exposed rabbits were about 15-fold in comparison with the controls after 2 weeks exposure and remained at this level after further exposure, but when zinc was given with lead the blood lead level doubled from 2 weeks to 4 weeks. In rabbits having both lead and zinc, the cerebral lead concentration was much lower than in rabbits exposed only to the respective amount of lead. No such effect was found in the cerebellum or sciatic nerve. Zinc did not prevent lead accumulation in the parenchymal tissues. Only a rather low induction of drug metabolizing enzyme activities was found in the liver of lead-exposed rabbits and zinc did not modify this induction. The results suggest that, although zinc might delay the lead accumulation in the cerebrum, it has little value in preventing peripheral neuropathy or metabolic alterations caused by lead.

Animals↗
PubMed1982

Induction of aryl hydrocarbon hydroxylase activity in cultured human lymphocytes.

Lymphocytes from a non-cancer population (203) of non-smokers, former smokers and smokers were cultured in vitro and assayed for basal and induced AHH activity. A wide range of AHH activities was measured, but there was no indication of separate groups in the distributions of the activities or inducibility. However, smoking slightly increased the basal AHH activity and significantly decreased the inducibility. AHH activity was dependent on the age of the donor, on the season, and correlated with lymphocyte stimulation by mitogens. A lung-cancer population (49 persons) was also tested. They were all smokers, but gave results that were more like those of non-cancer non-smokers, except for the fact that 37% of them gave a basal AHH activity that was too low to be measured, compared to 16% of the non-cancer persons. The observations that many factors, such as season, age and even smoking, affect the AHH activity necessitate a careful control of conditions for the study of the association between AHH inducibility in human lymphocytes and lung cancer. As cancer itself may also have an effect such a study should be done as a prospective study of a selected population.

Adult↗