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Biomedical subjects

H Vainio

Publications and source records attributed to H Vainio.

At least 235 records · Page 13Linked to original sources
PubMed1983

Spontaneous abortions in an industrialized community in Finland.

Spontaneous abortions were analyzed in an industrialized Finnish community according to the occupation and workplace of both the women and their husbands. Information about spontaneous abortions and births was obtained from the hospital discharge register, and data about the women and their families were collected from census files. When compared with all women employed outside the home, women who worked at a textile plant (factory A, a clothing manufacturer) had an increased rate of spontaneous abortion (16.7 per cent vs 11.4 per cent). The rate of spontaneous abortions among women employed at factory A differed according to the husband's workplace. The odds ratio for women employed at factor A whose husbands worked at a large metallurgical factory was 3.8, whereas the odds ratio for women whose husbands worked elsewhere was 1.2. Between 1973 and 1976, the rate of spontaneous abortions in this town was consistently lower for the summer period. (May-August) than for the other periods of the year.

Abortion, Spontaneous↗
PubMed1983

Embryotoxic effects of phtalic acid derivatives, phosphates and aromatic oils used in the manufacturing of rubber on three day chicken embryos.

Several chemicals that are used for manufacturing of rubber were tested for embryotoxicity on three day chicken embryos. Cyclohexylthiophtalimide was the most potent of the chemicals, with an ED50 value for the total embryotoxic effect 0.04 mumol (10 micrograms) per egg. Phtalic anhydride was about ten times less potent, having the total ED50 for total embryotoxicity 0.38 mumol (56 micrograms) per egg. Two esters of phtalic acid, dibutylphtalate and butylbenzylphtalate, instead, were relatively impotent, with ED50 values of about 33 mumoles and 27 mumoles per egg, respectively. Two phosphates, tricresylphosphate and synthetic arylphosphate, were not potent embryotoxic agents in the chick embryos. They had ED50 values of 7.0 mumoles (2.6 mg) per egg and 9.5 mg per egg, respectively. Sodium phosphate (NaH2PO4) had the ED50 11 mumoles per egg. Three types of oils were tested, too. A mixture known as "highly aromatic oils" was the most potent, with the ED50 31 micrograms per egg. "Low aromatic, paraffin base oils" was the next potent, with the ED50 87 micrograms per egg, while "naphtenic oils" had the ED50 480 micrograms per egg. Cyclohexylthiophtalimide and phtalic anhydride caused malformations at high frequency. The oils and tricresylphosphate appeared to be efficient teratogens under the experimental conditions used.

Abnormalities, Drug-Induced↗
PubMed1983

Toxicity of rubber chemicals towards three-day chicken embryos.

Three-day chicken embryos were exposed to 80 different rubber chemicals dissolved in either acetone or water. The following classes of chemicals were studied: thiurams, dithiocarbamates, thioureas, benzothiazoles, benzenesulfohydrazide, dithiodimorpholine, amines, acrylates, guanidines, resorcinol, phthalates, adipates, phosphates, oils, peroxides, heavy metal salts, and sodium nitrite. Dose-response curves and median lethal doses (LD50) or median effective doses (ED50) were calculated for mortality in 2 d after the treatment, for total mortality in 11 d after the treatment, and for the total effect, including deaths and malformations 11 d after the treatment, when the test was finished. Sixteen of the chemicals had no effect on the embryos when injected into the air chamber. Incomplete and irregular dose-response curves for the total effect were obtained with 13 of the chemicals. For them, the ED50 could be calculated. Among the remaining 51 chemicals, the most potent were the dithiocarbamates and cadmium and copper acetates, with the total effect ED50 from 2.4 to 160 nmol/egg. Other chemicals that had an ED50 smaller than 100 nmol/egg were thiurams, cyclohexylthiophthalimide, acrolein, and dithiodimorpholine. The majority of the chemicals had an ED50 between 100 nmol/egg and 10 mumol/egg. The least potent were sodium nitrite and methylmethacrylate with an ED50 of 22 mumol/egg. All the 64 embryotoxic chemicals caused malformations with only one exception (dibutylthiourea). The maximum observed frequencies of malformed embryos varied from 3 to 100% of the treated embryos.

Abnormalities, Drug-Induced↗
PubMed1983

Genetic toxicity of styrene and some of its derivatives.

Styrene, an important plastic monomer, is mutagenic after metabolic activation in several test systems. Probably because of an unfavorable activation : inactivation ratio, some mutagenicity assays have not, however, found styrene mutagenic. Styrene is converted by microsomal monooxygenases in vivo to styrene-7,8-oxide, which is a well-known mutagen. Arene oxides have also been proposed as the reactive metabolites of styrene, but the significance of these compounds is not yet fully understood. Only few derivatives of styrene have been tested for mutagenicity. The results are characterized by difficulties in metabolic activation. Many styrene-7,8-oxide analogues substituted at the phenyl ring are electrophilic reactants and mutagenic in vitro. Human whole-blood lymphocyte cultures have a peculiar feature, ie, styrene and many of its analogues substituted at the ring or vinyl chain induce sister chromatid exchanges in the cultured cells without exogenous metabolizing systems. This activation is brought about by erythrocytes present in the cultures and probably results from the conversion of styrenes to styrene-7,8-oxides.

Animals↗
PubMed1983

Genotoxic hazards in the rubber industry.

The toxicology of chemicals used in the rubber industry is poorly known. In the present investigation an attempt was made to use biological monitoring methods to identify job categories with possible exposure to potentially genotoxic chemicals. Urine samples were collected and analyzed for mutagenic activity by the bacterial fluctuation test. The highest individual mutagenic activities were detected among the workers in the weighing and mixing departments, and some high individual values were found among vulcanizers. Sister chromatid exchanges (SCE) and structural chromosome aberrations were also analyzed from samples of peripheral blood. The effect of smoking was clearly associated with significantly increased numbers of SCEs and chromosome aberrations. Among the workers in different job categories, the highest SCE frequencies were found for mixers who smoked. Also nonsmoking cleaners of the mixing department differed significantly from the nonsmoking referents in this respect. However, only the group of nonsmoking weighers showed an increase in the number of chromosome aberrations (p less than 0.01) when compared with the referents. The results suggest the need for improved occupational hygiene in the weighing and mixing departments of rubber plants so that exposure to potentially hazardous genotoxic chemicals can be decreased.

Chromosome Aberrations↗
PubMed1983

Biological monitoring in surveillance of exposure to genotoxicants.

Biological monitoring comprises analysis of samples taken of individuals with presumed or known exposures in order to estimate either the body uptake of a toxicant or to detect reversible effects of the exposure. In medical surveillance, biological monitoring is a preventive tool whose function is either to identify the hazardous exposures, or the early biological effects of such exposures. Biological monitoring is of special importance in identifying exposures to genotoxicants, for which no safe thresholds are known and the effects of which are prone to large interindividual variations. Both the uptake of the genotoxicant(s) and their biological effect should be considered determinants of the hazard potential of the exposure. Thus the occurrence of either one of these phenomena is a reason for preventive health measures.

Alkylating Agents↗
PubMed1983

A chromosome study among worker groups in the rubber industry.

Two cytogenetic endpoints, structural chromosome aberrations and sister chromatid exchanges, were analyzed in the blood lymphocytes of several worker groups and referents for an evaluation of possible work-related exposures to chromosome-damaging agents. A total of 35 referents and 55 rubber workers, the latter representing six job categories in two rubber factories, were included in the study. The two job categories frequently revealing increased sister chromatid exchanges or chromosome aberrations were mixers and weighers of chemicals. Statistically significantly increased sister chromatid exchange values were found among the weighers and the mixers. When chromosome aberrations were analyzed, only the group of nonsmoking weighers showed significantly higher values than the reference group. Smoking was found to correlate with increased frequencies of sister chromatid exchanges and chromosome aberrations among both the workers and the referents.

Adult↗
PubMed1983

Spontaneous abortions among rubber workers and congenital malformations in their offspring.

Spontaneous abortions of hospitalized women and congenital malformations were analyzed among rubber workers to investigate the possibility of an association between reproductive problems and chemical exposures in the rubber industry. Information on workers was obtained from the membership register of the Union of Rubber and Leather Workers and from the personnel register of a rubber factory. The frequencies of spontaneous abortions did not appreciably differ when the pregnancies occurred during Union membership or during employment in the factory as compared with the pregnancies occurring before or after that time. A case-referent study concerning the association between different exposures and spontaneous abortions showed that the odds ratio for factory workers exposed to rubber chemicals was increased in the footwear department. A corresponding risk was not observed in the tire department. The contradictory observations may be explained by concomitant exposure to solvents in the footwear department or by other nonoccupational factors. The possible association between congenital malformations and exposures in the rubber and leather industries was studied by the case-referent technique. No significant increase in the risk of malformations was observed in any branch of employment. However, the numbers of malformations were rather small.

Abnormalities, Drug-Induced↗
PubMed1983

Metabolic activation of styrene by erythrocytes detected as increased sister chromatid exchanges in cultured human lymphocytes.

Styrene induces sister chromatid exchanges (SCEs) in human whole-blood lymphocyte cultures without exogenous metabolizing systems, which indicates that styrene is metabolically activated in this in vitro system. Whole-blood lymphocyte cultures from 11 male donors showed a clear increase in SCEs after a 48-hr treatment with styrene (2 mM) or with the reactive metabolite styrene 7,8-oxide (0.15 mM). Styrene (0.5 to 4 mM) induced a distinct dose-dependent increase of SCEs in whole-blood cultures (with 200 to 400 million red blood cells/ml) but only a slight effect in purified lymphocyte cultures (with 20,000 red blood cells/ml). SCE induction by styrene (2 mM) depended on the amount of red blood cells (0.02 to 2000 million/ml) added to the purified lymphocyte cultures. Cyclophosphamide, studied for comparison, clearly increased SCEs irrespective of the presence of erythrocytes. The results show that erythrocytes are essential for the activation of styrene in the lymphocyte test system. This activation probably results from the conversion of styrene into styrene 7,8-oxide by oxyhemoglobin.

Biotransformation↗
PubMed1982

Spontaneous abortions in hospital staff engaged in sterilising instruments with chemical agents.

Spontaneous abortions in hospital sterilising staff were analysed using data from a postal questionnaire and a hospital discharge register. The study included all the sterilising staff employed in Finnish hospitals in 1980; the controls were nursing auxiliaries. Data from the questionnaire showed that the frequency of spontaneous abortions was 11.3% for the sterilising staff and 10.6% for the nursing auxiliaries. When the staff were concerned in sterilising procedures during their pregnancy the frequency was 16.7% compared with 5.6% for the non-exposed pregnancies. Adjustment for age, parity, decade of pregnancy, smoking habits, and intake of coffee and alcohol did not affect the differences. The increased frequency of spontaneous abortion correlated with exposure to ethylene oxide but not with exposure to glutaraldehyde or to formaldehyde. Analysis of spontaneous abortions from the hospital discharge register confirmed the findings. Thus the results from the two independent analyses suggest that exposure to ethylene oxide in hospitals may carry a risk of spontaneous abortion among sterilising staff.

Abortion, Spontaneous↗
PubMed1982

Biologic monitoring of exposure to chemical mutagens in the occupational environment.

Occupational exposure to chemical mutagens can be monitored by measuring the chemical interaction that occurs between the exposing agent and biologic macro-molecules. Such interaction is detectable in the body fluids as adducts of, e.g., DNA or glutathione. The mutagenic compounds or their metabolites can also be measured from urine samples, by use of bacterial mutagenicity assays. Much basic research is still needed before these methodologies are applicable for routine monitoring. At present, cytogenetic approaches appear to be nearest to routine surveillance in detecting early biologic effects in exposed humans. Studies on structural chromosome aberrations or sister chromatid exchanges (SCEs) in peripheral blood lymphocytes obviously detect different molecular injuries, and the results from in vivo occupational exposures do not necessarily correlate. Somatic chromosome damage should always be considered a warning sign of potentially adverse effects, and such damage should lead to decreased exposure to the causative agent.

Chromosome Aberrations↗
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

Embryotoxicity of industrial chemicals on the chicken embryo: thiourea derivatives.

Six thioureas: 1,3-diphenylthiourea (DPTU), 1,3-dibutylthiourea (DBTU), tetramethylthiourea (TEMTU), trimethylthiourea (TRIMTU), 1,3-diethylthiourea (DETU), and 1,3-ethylenethiourea (ETU), were tested, in addition to carbon disulfide, on three day chicken embryos for embryotoxicity. The parameters measured were early deaths, recorded within two days of injection, late deaths of malformed embryos, late deaths of non-malformed embryos, and malformed survivors. The order of total embryotoxicity decreased as follows DBTU greater than DPTU greater than TEMTU greater than TRIMTU greater than DETU greater than ETU. The range for ED50 values for total embryotoxicity was from 0.28 (DBTU) to 4.5 (ETU) mumol/egg. DBTU caused early deaths but no malformations. TEMTU and DPTU were the most potent teratogens.

Abnormalities, Drug-Induced↗