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Biomedical subjects

H Vainio

Publications and source records attributed to H Vainio.

At least 271 records · Page 15Linked to original sources
PubMed1981

Childhood cancer and parental occupation in Finland.

A case-control study was conducted of the occupations of parents of children under 15 with diagnosed malignancies. The total series contained all childhood cancers cases reported to the Finnish Cancer Registry during the period 1959-75. The parental occupations, recorded at the time of pregnancy, were collected from maternity welfare centres. The cases were analysed as a singly group or as subgroups according to the diagnoses-brain tumours, leukaemia, and all other malignancies. The maternal occupations found more frequently among cases than controls included farmers' wives (1959-68 only), pharmacists, saleswomen, bakers, and factory work of an vehicle driving, machine repair, painting, and the work of men who gave an academic degree as their occupation. Some of these occupations involve possible exposure to harmful chemicals, although chance correlations cannot be excluded.

Adolescent↗
PubMed1981

Chromosome aberrations and their relevance to metal carcinogenesis.

Scoring for structural chromosome abnormalities is one of the only practical methods available for detecting visual damage in human genetic material. Cytogenetic tests in vivo and in vitro have shown the clastogenic potential of a number of metals and metal compounds. The difficulties in in vivo studies lie in identifying a specific clastogen in an occupational setting, where simultaneous exposure to a number of organic and inorganic chemicals is a common phenomenon. Metals known to be carcinogens in animals also tend to possess chromosome-damaging properties, even though more extensive studies are needed before any conclusive evidence can be reached. The visible chromosomal damage produced by exposure to metal compounds should be considered as a warning indication of potentially adverse genetic and somatic effects in humans.

Aging↗
PubMed1981

Dose-dependent effects of vinyltoluene inhalation on non-protein thiols and drug biotransformation in liver and kidneys of the rat.

1. Male Wistar rats were exposed to atmospheres of 50, 100 or 300 p.p.m vinyltoluene 6h/day, 5 days/week, for one or two weeks. 2. Hepatic non-protein sulphydryl content decreased in a dose-dependent manner when measured 0.5 h after the last exposure, both after one and two weeks. 3. The content of hepatic non-protein sulphydryl groups progressively increased 20 h after stopping the vinyltoluene exposure. 4. The activity of 7-ethoxycoumarin O-deethylase showed a dose-dependent increase both in liver and kidneys. The activity of UDP-glucuronosyltransferase also increased in a dose-related manner in both organs studied.

Animals↗
PubMed1981

Formaldehyde exposure in work and the general environment. Occurrence and possibilities for prevention.

Formaldehyde is extensively used for many different purposes. For this reason, serious concern has been expressed about the health hazards related to its potent irritating and sensitizing properties. Recently published information about the potential carcinogenicity of formaldehyde has generated further discussion of the potential health hazards of this compound. This article briefly reviews the health hazards of formaldehyde, the occurrence of formaldehyde in the environment, and general aspects of the prevention of existing hazards.

Air Pollutants↗
PubMed1981

Effects of intermittent dichloromethane inhalation on blood carboxyhemoglobin concentration and drug metabolizing enzymes in rat.

Rats were exposed to dichloromethane vapor in concentrations of 500 ppm, 1000 ppm, or 1000 ppm as a time-weighted average. All of the exposures lasted for 6 h, five days a week for two weeks. Kidney microsomes displayed a dose-dependent enhancement of the ethoxy-coumarin O-deethylase activity. After the second week the enhancement was accompanied by an increase in the renal glutathione content. In the liver, the UDP-glucuronosyltransferase activity showed a dose-dependent increase and the NADPH-cytochrome c reductase activity decreased. The hepatic glutathione content remained unchanged. Dichloromethane exposure did not affect the hemoglobin concentration of the blood. An 8 to 9% COHb concentration was found after exposure in all of the study groups. The similarity of COHb concentrations suggest that, in the rat, the metabolic pathway converting dichloromethane to CO is saturated already at the lowest exposure level under study.

Animals↗
PubMed1981

Monitoring genotoxicity in the occupational environment.

New methods need to be developed for the biological monitoring and health surveillance of workers occupationally exposed to mutagenic and carcinogenic chemicals. Two potential approaches, the assay of urine for mutagenicity and the analysis of chromosomal changes in lymphocytes of workers, are discussed in this report with respect to experience in two occupational environments, the rubber industry and a hospital oncology unit. The urine of workers in the rubber industry has shown significantly increased mutagenic activity after the workweek in comparison to postvacation values. Handling cancer chemotherapeutic drugs in oncology units may cause exposure to the cytostatics, many of which are known mutagens and carcinogens. This exposure can be detected as an increased sister chromatid exchange frequency in cultured lymphocytes.

Antibiotics, Antineoplastic↗
PubMed1980

Mutagenic activity in foundry air.

Organic, cyclohexane soluble foundry air contaminants were assayed for their mutagenic activity with the Ames test. The samples studied were also analyzed for benzo(a)pyrene (BaP) concentrations by glass capillary gas chromatography. All the samples showed mutagenicity towards the strains Salmonella typhimurium TA 98 and TA 100 after metabolic activation. Correlations between the amount of BaP and the mutagenicity were calculated and then compared to the corresponding dose response correlations of known BaP concentrations.

Air Pollutants↗
PubMed1980

Comparison of alkylation rates and mutagenicity of directly acting industrial and laboratory chemicals: epoxides, glycidyl ethers, methylating and ethylating agents, halogenated hydrocarbons, hydrazine derivatives, aldehydes, thiuram and dithiocarbamate derivatives.

Groups of industrial and laboratory chemicals were tested for their alkylation activity using 4-(p-nitrobenzyl)-pyridine and deoxyguanosine as nucleophiles. The alkylation activity was compared with mutagenicity of the chemicals to E. coli WP2 uvrA without metabolic activation. All the epoxide-containing compounds including simple epoxides and glycidyl ethers elicited alkylation activity and mutagenicity. Furthermore there was a reasonable correlation between the rate of alkylation and the mutagenic potency. All the methylating and ethylating compounds tested were active but no correlation was observed between the rate of alkylation and the mutagenic potency, apparently due to the different types of alkylation products formed. The other compounds tested including halogenated hydrocarbons, hydrazine derivatives, aldehydes, thiuram and dithiocarbamate derivatives elicited a slow or no alkylation activity while many of the compounds were mutagenic. There was no evidence among the chemicals tested of an alkylating non-mutagen. Thus evidence of alkylation activity appears to indicate mutagenic risk.

Aldehydes↗
PubMed1980

Spontaneous abortions among women employed in the metal industry in Finland.

Spontaneous abortions were analyzed among Finnish metal workers between 1973 and 1976. The information on the workers (35,000 women) was obtained from the files of the Union of Metal Workers; information on the abortions was obtained from the Hospital discharge registry of the National Board of Health. Among metal workers 195 spontaneous abortions were recorded. The proportion of spontaneous abortions was 7.82% (spontaneous abortions/pregnancies, rate) and 13.79% (spontaneous abortions/births, ratio) of which the latter figure was significantly higher (P < 0.05) than the respective one among all Finnish women. Both the rate and the ratio were significantly increased upon joining the Union as analyzed from an age-standardized material. A particular risk industry appeared to be the production of radios, televisions, and their components. An exposure to solder fumes was suggested to explain the increased risk.

Abortion, Spontaneous↗
PubMed1980

Biotransformational and neurophysiological changes in rabbits exposed to lead.

Lead was administered to adult male rabbits in drinking water at a 0.1% concentration for four and five week periods. The lead contents were determined in the central and peripheral nervous tissues and in the liver, kidney, and intestinal mucosa. The conduction velocity of sciatic nerve and the activities of drug metabolizing enzymes in other tissues were determined. The lead concentration in the blood was at a steady state at four to five weeks of exposure. Lead accumulated in all tissues except the brain. The brain lead concentration was 40 to 50% of that in the blood, indicating the existence of a blood-brain barrier. However, the lead concentration in the sciatic nerve increased significantly from four to five weeks of exposure and exceeded that in the blood. This indicates the lack of a blood-nervous tissue barrier in the sciatic nerve allowing a continuous accumulation of lead. This accumulation affected the function of the sciatic nerve; motor nerve conduction velocity decreased from the control level (58.3 +/- 7.4 m/sec) to 43.8 +/- 6.3 m/sec after the four-week exposure and to 35.0 +/- 1.3 m/sec at 5 weeks of exposure. After five weeks of exposure, no changes in the hepatic, intestinal, or renal drug metabolizing enzyme activities were found. These results suggest that motor nerve conduction velocity is affected by lead exposure prior to any influence on biotransformation enzymes.

Animals↗
PubMed1980

Glutathione depletion in isolated rat heaptocytes caused by styrene and the thermal degradation products of polystyrene.

Depletion of reduced glutathione (GSH) was induced in isolated rat hepatocytes incubated with styrene or exposed for 120 min to products from oxidative thermal degradation of polystyrene. The depletion depended on the concentrations of styrene and on the degradation temperature. Styrene (1 mM) or products from degradation of polystyrene at 200 degrees C (concentration of styrene in exposure atmosphere 0.7 ppm) had no detectable effect on glutathione levels in isolated hepatocytes. At higher degradation temperatures (250 degrees C and 300 degrees C, with styrene concentrations of 2.5 and 25 ppm, respectively) a rapid depletion was detected as well as with 3 mM styrene in incubation mixture. The latency of lactate dehydrogenase was affected neither by the polystyrene degradation products nor by the styrene added to the incubation mixture.

Animals↗