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Biomedical subjects

K Hemminki

Publications and source records attributed to K Hemminki.

At least 415 records · Page 23Linked to original sources
PubMed1983

Assessment of methods and results of reproductive occupational epidemiology: spontaneous abortions and malformations in the offspring of working women.

Epidemiological studies relating occupational exposures of working women to spontaneous abortions and malformation are reviewed and some methodological considerations are presented. The reproductive epidemiology is less developed than epidemiology in general and seems to involve some specific problems. The ascertainment of exposure and of outcome may be problematic. The exposures may be reported differently by the women depending on the outcome of the pregnancy; thus confirmation of exposure from an independent data source would be an asset. The recognition of spontaneous abortions by women is variable and this should be considered in the study design. An access to medical records could provide objective data on the outcome, but it may introduce other types of asymmetries. The types of occupational exposures of the women, suggested to carry a risk of spontaneous abortions, include anesthetic agents, laboratory work, copper smelting, soldering, and chemical sterilization using ethylene oxide and glutaraldehyde. Maternal employment in laboratories and exposure to solvents has been linked to a risk of congenital malformations in the offspring in five studies. Data on the teratogenic effects of anesthetic gases has been conflicting. In one study, employment in copper smelting was associated with malformations in the offspring.

Abnormalities, Drug-Induced↗
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

Toxicity of rubber chemicals in the chicken embryo. How to interpret results from animal tests.

Results from 80 rubber chemicals in the chicken embryo test were reviewed and compared, when data were found, to results on teratogenicity in mammalian test systems. In addition other sources of literature were used to compare the chicken embryo test to the mammalian tests. Furthermore the results from animal models were analyzed in terms of their ability to predict teratogenicity in humans.

Abnormalities, Drug-Induced↗
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↗
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

Dimethylnitrosamine adducts excreted in rat urine.

Rats were injected with [14C]dimethylnitrosamine and urine was collected up to 5 days after the injection. Urine samples were concentrated and subjected to Sephadex G-10 chromatography. Three peaks of radioactivity (I-III, in the order of elution) were observed for all injection times. The peaks were analysed further by cation exchange and thin-layer chromatography and by phase-separation (pH-determination). The pK-determinations and the chromatographic properties suggested that Sephadex fraction I composed of methylated amino acids, such as N-acetyl-S-methylcysteine, 1-methylhistamine and S-methylcysteine, in addition to radioactive methionine. Sephadex fraction II was suggested to compose of allantoin and of a metabolite of thiazolidine-4-carboxylic acid. The latter compound was a reaction product of formaldehyde and cysteine, indicating activity of the formaldehyde moiety released from dimethylnitrosamine. By gel filtration properties Sephadex fraction III indicated identity as 7-methylguanine. Although the urinary radioactivity accounted for about 9% of the applied dose.

Animals↗
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

Community study of spontaneous abortions: relation to occupation and air pollution by sulfur dioxide, hydrogen sulfide, and carbon disulfide.

Spontaneous abortions were analyzed in an industrial community in Finland in relation to the occupation of women and their husbands, and to the level of air pollution in the family's residential area. Information on abortions and births was obtained from the hospital discharge register; information on the women and their families was obtained from the files of the population and housing census. Women who were employed in rayon textile jobs and paper products jobs had an increased rate (P less than 0.10) of spontaneous abortions; the wives of men employed in transport and communication, in rayon textile jobs, and in chemical process jobs also had an increased rate of spontaneous abortions. In material stratified for age, parity, and socioeconomic class no evidence was found that the level of sulfur dioxide or carbon disulfide could be associated with a risk of spontaneous abortions. More spontaneous abortions were noted in all socioeconomic classes in areas where the mean annual level of hydrogen sulfide exceeded 4 micrograms m-3. However, the difference (total rates 7.6 and 9.3, respectively) was not significant statistically.

Abortion, Spontaneous↗
PubMed1982

Urinary sulfur containing metabolites after administration of ethanol, acetaldehyde and formaldehyde to rats.

Acetaldehyde and formaldehyde react in vitro with cysteine to form a product, probably a thiazolidine derivative, which eluted as a single peak in cation exchange chromatography. The reactivity of formaldehyde was much higher than that of acetaldehyde. Rats were injected with single dose of 7.6, 6.2 and 2.5 mmol, respectively of ethanol, acetaldehyde and formaldehyde, and urine was analysed for alkali-hydrolysable thiol groups. Acetaldehyde caused a significant increase in urinary alkali-hydrolysable thiols. Ethanol and acetaldehyde treatment stimulated the ability of the urine to catalyse the iodine-azide reaction suggesting the presence of an excess of compounds containing C-S-atoms.

Acetaldehyde↗
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↗
PubMed1982

Gastroschisis and omphalocele in Finland in the 1970s: prevalence at birth and its correlates.

Information on liveborn and stillborn children with gastroschisis and omphalocele was collected from hospital and register sources in Finland from 1970 to 1979. The apparent prevalence of gastroschisis at birth increased from 0.77/10 000 births in 1970-4 to 1.42/10 000 in 1975-9. The prevalence of omphalocele (1.96/10 000) was unchanged during the decade. Even for gastroschisis the apparent increase in prevalence was noted for northern Finland only, while for southern Finland the prevalence has been stable during the 1970s, possibly suggesting diagnostic or reporting differences between various parts of the country. Some correlates of increased risk of gastroschisis included: low birth weight, low maternal age, urban residence, and maternal employment in commercial and sales work.

Abdominal Muscles↗
PubMed1982

Application of the chicken embryo in testing for embryotoxicity: thiurams.

A test protocol was developed for the testing of chemicals for toxicity on the chicken embryo. The protocol called for a continuous monitoring of the developing embryo for those that died before maceration. The eggs were injected on day 3, and the test was continued up to day 14 of incubation. The following parameters of embryotoxicity were used: early deaths (spanning the first 2 d after injection), late deaths with malformed embryos, late deaths with nonmalformed embryos, and malformed survivors. The order of embryotoxic potency, in descending order, among the thiurams was tetramethylthiuramdisulfide, tetramethylthiurammonosulfide, tetraethylthiuramdisulfide. It was found that late deaths were seen in 70% of the cases with malformations. The most common types of malformations were eye defects and open coeloms. Dead embryos frequently had multiple malformations. In lethal cases, embryonic development terminated at stages 25/26 and 29 on the Hamburger-Hamilton scale.

Abnormalities, Drug-Induced↗