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Biomedical subjects

M Nurminen

Publications and source records attributed to M Nurminen.

At least 109 records · Page 6Linked to original sources
PubMed1977

Clozapine-induced agranulocytosis. A genetic and epidemiologic study.

An epidemic of agranulocytosis and granulocytopenia occurred in 1975 in conjunction with clozapine treatment of mental patients in Finland. An attempt was made to assess the epidemiologic and genetic factors contributing to the adverse drug effect. The estimated incidence rate in Finland was 2.1/1000 patient-months. This figure could not be compared with rates from other countries because of the inexact nature of the figures reported so far. All 16 cases occurred in seven hospitals in southwestern Finland, whereas the overall hospital net use of the drug was geographically evenly distributed. The difference between the observed and the proportionally expected incidence of cases amongst the hospitals where clozapine was used was statistically significant. The average consumption of the drug did not differ between the hospitals where cases occurred and those where no definite cases could be diagnosed. Six-generation pedigree analyses failed to reveal significant parental consanguinity or genetic kinship between probands. Neither did the birth places of the ancestors of the probands disclose a typical isolate pattern. In conclusion, the cases appeared to be confined to a few hospitals in southwestern Finland. Although a genetic factor is not excluded, we found no evidence in support of a genetic mechanism.

Agranulocytosis↗
PubMed1977

Mouse virulence of Salmonella typhimurium mutants deficient in two major outer membrane proteins.

The role of several outer membrane components as virulence factors is well established. We have now isolated spontaneous mutants and conjugational hybrids of smooth mouse virulent Salmonella typhimurium deficient in two major outer-membrane proteins. The lack of the 34,000- and/or 36,000-dalton proteins was confirmed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Mutants and recombinants were then tested for their mouse virulence by intraperitoneal inoculation and were found to be as virulent as the parent strain.

Animals↗
PubMed1976

Survival experience of a cohort of carbon disulphide exposed workers from an eight-year prospective follow-up period.

A cohort of 343 men from a viscose rayon factory in Finland with at least five years of exposure in carbon disulphide (CS2) was followed from 1967 to 1975 with respect to coronary heart disease (CHD) mortality. The exposed cohort had over twofold excess death rate from CHD relative to a matched reference group. Statistical separation of causes other than CHD revealed a difference of two years in the life expectancies of the two populations for the age interval of 25 to 54 years. The coronary mortality had, however, decreased since protective measures were instituted at the plant after the fifth year of follow-up, leaving only one-fifth of the original group exposed and reducing the level of CS2 exposure for them to less than 10 ppm. This trend, although tentative due to the limited experience after the intervention, seems to suggest that the risk of coronary death for the formerly excessively exposed workers can be influenced and lessened to a normal level.

Adult↗
PubMed1976

T2 lipopolysaccharide antigen of Salmonella: comparison of the properties of T2 and mucoid forms.

The T2 form of Salmonella was found to resemble mucoid mutants to some extent by growing as rather slimy colonies, especially at low temperatures. Its sensitivity to rough-specific phages was greatly reduced at low temperature. However, the T2 form did not produce colanic acid. The mucoid mutants of Salmonella studies corresponded to previously described mucoid mutants of Escherichia coli culturally, chemically,and genetically.

Escherichia coli↗
PubMed1976

Bacteriophage-resistant mutants of Salmonella typhimurium deficient in two major outer membrane proteins.

Mutants resistant to bacteriophages (P221 and PH105 or PH51) were isolated from a rfa strain of Salmonella typhimurium. They were found deficient in separate 33,000- to 36,000-dalton band proteins (major band proteins). Double mutants derived from both types of mutants were deficient in both of the bands. The growth behavior of all the mutants was normal. The outer membrane of the mutants appeared to be more wrinkled than normal and formed vesicles in many of the mutants. In freeze-fractured cells, changes were seen in the outer membrane (particleless patches in the concave fracture face, the particles themselves being smaller than normal). These changes were more marked in the double mutants.

Adsorption↗
PubMed1976

Behavioral effects of long-term exposure to a mixture of organic solvents.

The behavioral effects of long-term exposure to a mixture of organic solvents were investigated in a comparison of the test results of 100 car painters with those of a reference group. The test battery included tests for intelligence, memory, psychomotor performances, and personality. In addition to the comparison of the mean results, two discriminant function analyses were made. In one, only the performance test variables were used, but in the other personality variables were also included. The results indicated impairments in psychological performances, as well as personality changes in the exposed group. Impairments in visual intelligence and verbal memory and a reduction of emotional reactivity were the central features of the adverse effects of solvent exposure, but the behavioral disturbances also involved several other functions, including performance on a verbal intelligence test. The possible role of the differences in the initial intelligence levels were controlled with a separate comparison of the test results of 33 pairs of exposed and nonexposed subjects who were matched for age and for their intelligence level, measured during the military service. The discriminant function analyses were based on the results of these matched subgroups and tested in the rest of the material. According to the results the sensitivity of the psychological test methods was high, but the specificity somewhat low, with regard to solvent exposure. The concentration of various solvents included in the exposure of car painters were low, the summated exposure corresponding corresponding to 32% of the Finnish threshold limit value. The possible role of a potentiating effect of the solvent in the development of behavioral disturbances is discussed.

Adult↗
PubMed1976

Eight-year follow-up of viscose rayon workers exposed to carbon disulfide.

An 8-year follow-up of workers exposed for at least 5 years to carbon disulfide showed an excess of deaths due to coronary heart disease in reference to a comparison cohort. However, after effective preventive measures, e.g., leaving only 19% of the original group exposed and reducing the level of exposure to less than 10 ppm, had been undertaken after the 5th year of follow-up, coronary mortality decreased and no excess mortality during the last 3 years of follow-up occurred. These results, although only suggestive -- due to the small number of deaths and the short time of follow-up after the intervention -- seem promising from the point of view of improving the prognosis of workers who have already accumulated an excess risk for coronary death.

Adult↗
PubMed1976

A mortality study of foundry workers.

The mortality of foundry workers was studied from a sample of all those men employed in 20 representative iron, steel, and nonferrous foundries for any period of time during 1950 through 1972. A statistical sample of 3,876 men from all those 15,401 workers with at least 3 months' exposure formed the cohort under study. The actual number of person-years of follow-up became 47,160. Total and cause-specific mortality was studied in the entire cohort and in different categories based on exposure time and occupation. The foundry workers' experience was compared to that expected on the basis of the general male population's death rates in Finland, and different categories of the cohort were compared to each other through direct standardization. During the period from 1950 through 1973, there had occurred 224 deaths. The mortality approached the expected value computed from the age-adjusted general male population, the standardized mortality ratio (SMR) being 90 for all foundry workers and 95 for workers in "typical" foundry occupations. The corresponding standard mortality ratios based on the estimated total number of person-years, after the application of corrections for sampling fractions, were 86 and 95, respectively. There was a slight shift of the age of death towards younger age groups among the casters, fettlers, and furnace tenders. Mortality from coronary heart disease showed a standardized mortality ratio of 80 for the whole cohort; no significant differences were found for any occupational category. Lung cancer mortality was higher than expected (SMR 150) in the entire cohort; closer analysis revealed that the excess was confined to iron foundries, and especially to molders with more than 5 years of exposure. There were no more violent deaths than expected, not even from work accidents. Because most occupational cohorts have standardized mortality ratios that are well below 90, the present results were interpreted as probably indicating slightly elevated mortality. The most important finding was the concentration of lung cancer among molders in iron foundries.

Accidents, Occupational↗
PubMed1975

A follow-up study of coronary heart disease in viscose rayon workers exposed to carbon disulphide.

In 1967 two cohorts of 343 men each were formed and matched with respect to age, district of birth, and similarity of work. One cohort comprised viscose rayon workers with at least five years' exposure to carbon disulphide during any period between 1942 and 1967, and the other cohort consisted of workers from a paper-mill with no such exposure. The concentrations of carbon disulphide and hydrogen sulphide in the workroom air had been measured regularly since 1950, and about 4000 measurements were available. In all probability the concentrations had been very high in the 1940s, between 20 and 40 ppm in the 1950s, and about 10 to 30 ppm from 1960 onwards. On examination in 1967 it was confirmed that all of the relevant coronary risk factors had been kept under control. The only exception to this was blood pressure which was slightly higher among the exposed workers, a finding that was interpreted as a result of exposure rather than an independent risk factor. A five-year follow-up showed that 14 men had died from coronary heart disease (CHD) in the exposed group, against three in the control group (P smaller than 0:007). Other causes of death were evenly distributed. In addition, 11 nonfatal first infarctions had occurred in the exposed group as compared with four in the control group. On re-examination in 1972, nearly 25% of the exposed men, against 13% of the controls, had a history of angina (typical, probable, and possible) as measured by the World Health Organization questionnaire (P smaller than 0:0002). The prevalence proportions of typical angina were 12% and 5% respectively (P smaller than 0:001). As opposed to this, only slight differences were apparent for coronary ECGs. The higher degrees of prevalance in the exposed group may well have been attributable to chance. As in 1967/68, the mean systolic and diastolic blood pressures were slightly higher in the exposed group (P smaller than 0:001 and P smaller than 0:01, respectively). The relative risk was 4-8 for fatal attacks, 3-7 for all infarctions, 2-8 for nonfatal infarctions, 2-2 for angina, and 1-4 for ECG findings indicative of CHD. This implies that with increasing severity and specificity of the manifestations the causal role of CS2 in developing CHD becomes more evident. Further, it is inferred that exposure to CS2 seems to worsen the prognosis of CHD in addition to increasing its incidence. Although the exposure data in this study may not be representative of the personal exposure of the workers, the conclusion is drawn that a great deal of justification exists for lowering the threshold limit value of 20 ppm recommended by the American Conference of Governmental Industrial Hygienists.

Air↗
PubMed1975

The epidermiologic relationship between pleural mesothelioma and asbestos exposure.

This paper describes an investigation of 85 notifications of either probable or possible mesothelioma to the Finnish Cancer Registry from 1953 through 1969. The investigation covers characteristic epidemiologic features and the possibility of the mesothelioma being connected with occupational or other exposure to asbestos. The incidence rate of pleural mesothelioma was estimated at 1.1 per million per year. The male/female ratio was 1.3:1, which greatly differed fsrom that for malignant neoplasms of the bronchus or lung in Finland in 1960. The mean age at dealth from mesothelioma was over 7 years lower than that for bronchial carcinoma. The ratio of the crude incidence rates for the urban and rural populations was 4.2; the corresponding ratio for cases of carcinoma oopulations was 4.2; the corresponding ratio for cases of carcinoma of the bronchus or lung was 1.2 in Finland in 1960. THE LAST OCCUPATIONS OF THE 82 DECEASED PERSONS, OBTAINED FROM THE DEATH CERTIFICATES, WERE DIVIDIED INTO THREE CATEGORIES ACCORDING TO POSSIBLE ASBESTOS EXPOSURE. Exposure was present or probable in 9 (11.0) cases, 28 (34.2 %) had a possible exposure, and in 33 (40.2 %) cases exposure was absent or unlikely. The occupation of 12 (14.6) persons was unknown. Additional information of possible exposure history was obtained by interviewing the relatives of 10 mesothelioma patients. For half of the persons a definite, although in some cases trivial, exposure to asbestos could be ascertained. For the other five persons no exposure, either occupational, neighborhood or domestic, to asbestos could be traced. The residental distribution of the 85 persons with mesothelioma revealed no clustering of cases.

Adult↗
PubMed1973

Mitogenic effect by lipopolysaccharide and pokeweed lectin on density-inhibited chick embryo fibroblasts.

The B lymphocyte mitogens, bacterial lipopolysaccharide (LPS), pokeweed lectin, and tuberculin, induced proliferation in density-inhibited monolayer cultures of chick embryo fibroblasts. The stimulation was seen both as an early increase in sugar uptake and cell volume and later as an increase in thymidine incorporation and cell number. The concentration of LPS maximally stimulating fibroblasts was remarkably low, about 0.1-1 ng/ml. LPS preparation with very different sugar chains gave quite similar results indicating that the architecture of the hydrophilic carbohydrate part is not critical for the mitogenic effect.

Animals↗