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Biomedical subjects

M Nurminen

Publications and source records attributed to M Nurminen.

At least 91 records · Page 5Linked to original sources
PubMed1982

Sauna and congenital defects.

To test a recent hypothesis on the causal relationship between sauna-induced hyperthermia and congenital defects, 100 consecutive cases of defects of the central nervous system and 202 cases of orofacial clefts were singled out from the Finnish Registry of Malformations. The mothers and their time-area-matched referents were interviewed for their sauna habits. Almost every pregnant mother (98.5%) had visited the sauna regularly, and yet, the incidence of the CNS defects in Finland is among the lowest ever reported. No differences in the sauna habits were observed between the case and referent mothers. It is concluded that the relatively mild, temporal hyperthermia caused by the sauna should not be considered hazardous for the developing embryo.

Body Temperature↗
PubMed1982

Cerebrospinal fluid cells and proteins in patients occupationally exposed to organic solvents.

Cerebrospinal fluid (CSF) cells and proteins were determined for 33 patients exposed to industrial organic solvents. A lymphoid reaction, i.e., a pathologically elevated number or percentage of enlarged lymphoid cells was observed in one-third of the patients, more often in patients with chronic intoxication (40%) than in those currently exposed to organic solvents (32%). An almost significant decrease of small lymphocytes in the CSF was observed among patients who had a past history of chronic solvent intoxication but no recent exposure. No cytological evidence of tissue destruction was found. Signs of slight blood--CSF barrier damage occurred in 5 (23%) of the currently exposed patients, but intrathecal IgG synthesis was not observed. Increased cellular activity in the CSF was also accentuated in principal component analysis. The results suggest slight nonspecific immunoactivation in the central nervous system of subjects exposed to organic solvents.

Adult↗
PubMed1982

Quantitated effects of carbon disulfide exposure, elevated blood pressure and aging on coronary mortality.

Risk function analysis was performed in order to clarify the relationship between coronary heart disease death rate and occupational carbon disulfide exposure along with two other important risk factors, elevated diastolic blood pressure and older age, in a data set obtained from a 10-year prospective follow-up of coronary mortality in two cohorts of over 340 male industrial workers in Finland. The sole effect of carbon disulfide on the coronary mortality was statistically significant (relative risk = 2.3), and it was largely independent of the level of the other two risk factors. Log-linear models were fitted to predict coronary heart disease deaths. The analysis identified the dual role of raised blood pressure in the potential mechanism of coronary death. Relative risks ranging up to 48 were obtained for the joint non-synergistic effect of these three factors in the exposed group compared to a subgroup of nonexposed, 40-year-old normotensive men. The effect of carbon disulfide exposure on the risk of coronary death, while clearly distinguishable from the effect of hypertension and aging, stayed subordinate to them, but nevertheless remained an important risk element in the work environment.

Adult↗
PubMed1981

Immunochemical characterization of major outer membrane components from Salmonella typhimurium.

We used crossed immunoelectrophoresis to study detergent-solubilized components of the outer membrane of Salmonella typhimurium under nondenaturing conditions. The antisera used were raised against nondenatured outer membrane preparations. Lipopolysaccharide and lipoprotein were identified easily as discrete precipitates when they were solubilized with Triton X-100. However, solubilization of the porins with Triton X-100 resulted in a complex precipitate pattern, indicating incomplete dissociation of protein-protein interactions. A clear-cut pattern was obtained when the porins were first solubilized and denatured with hot sodium dodecyl sulfate, followed by removal of the sodium dodecyl sulfate and renaturation in the presence of Triton X-100. Our findings suggested that crossed immunoelectrophoresis can be used to study the antigenicity of nondenatured porins and the antibody responses to them.

Bacterial Proteins↗
PubMed1981

Immunization with major outer membrane protein (porin) preparations in experimental murine salmonellosis: effect of lipopolysaccharide.

A crude major outer membrane (porin) preparation, obtained from a rough strain of Salmonella typhimurium earlier shown to be protective both in active and passive immunization of mice against challenge with smooth S. typhimurium, was further purified. Removal of the main impurities, lipopolysaccharide (LPS) and lipoprotein, was accompanied by loss of protective capacity in passive immunization experiments. Reconstitution with rough LPS restored the protective capacity. Protection was, however, concluded not to be due to anti-LPS, because a large fraction of the anti-LPS antibodies could be removed from the protective rabbit antiserum with an LPS immunosorbent without loss of protection.

Animals↗
PubMed1981

Hand-arm vibration in the aetiology of hearing loss in lumberjacks.

A longitudinal study of hearing loss was conducted among a group of lumberjacks in the years 1972 and 1974--8. The number of subjects increased from 72 in 1972 to 203 in 1978. They were classified according to (1) a history of vibration-induced white finger (VWF), (2) age, (3) duration of exposure, an (4) duration of ear muff usage. The hearing level at 4000 Hz was used to indicate the noise-induced permanent threshold shift (NIPTS). The lumberjacks were exposed, at their present pace of work, to noise, Leq values 96-103 dB(A), and to the vibration of a chain saw (linear acceleration 30-70 ms-2). The chain saws of the early 1960s were more hazardous, with the average noise level of 111 dB(A) and a variation acceleration of 60-180 ms-2. When classified on the basis of age, the lumberjacks with VWF had about a 10 dB greater NIPTS than subjects without VWF. NIPTS increased with the duration of exposure to chain saw noise, but with equal noise exposure the NIPTS was about 10 dB greater in lumberjacks with VWF than without VWF. With the same duration of ear protection the lumberjacks with VWF consistently had about a 10 dB greater NIPTS than those without VWF. The differences in NIPTS were statistically significant. The possible reason for more advanced NIPTS in subjects with VWF is that vibration might operate in both of these disorders through a common mechanism--that is, producing a vasoconstriction in both cochlear and digital blood vessels as a result of sympathetic nervous system activity.

Adult↗
PubMed1981

Temporal characteristics related to leave from work and pregnancy among mothers with congenitally malformed offspring.

The possible impact of occupational factors on the furtherance of congenital defects have been under study at our department for the past 4 years. The topic has assumed a special interest because of the importance of the issue involved, namely the search for a possibility to prevent teratogenesis, and partly because the applicable methods are different from those of "customary" epidemiology. In connection with a register-based, case-referent study utilizing supplementary information, acquired via questioning, of conditions at the mothers' work places, we analysed various time-related events in their pregnancy. We found that the groups compared differed from each other with regard to the correct timing of the birth, despite the fact that the distribution of the times of stopping work for various reasons were alike. Among mothers who were granted sick leave from work the diagnosis of anencephaly became less common close to the estimated date of delivery, and conversely for the diagnosis of hydrocephaly. The findings of the present study may suggest that the time of assignment for a statutory maternity leave be considered. Methodological issues in study design are also briefly discussed.

Congenital Abnormalities↗
PubMed1981

Impaired color discrimination among viscose rayon workers exposed to carbon disulfide.

A possible effect of chronic carbon disulfide exposure on the optic nerve was studied by giving the Farnsworth Munsell 100-Hue Test for color discrimination to 62 exposed and 40 nonexposed men. Carbon disulfide exposure did not relate to specific pattern defects in color discrimination, but impaired color discrimination occurred significantly more often in the exposed group than among the referents. The abnormal findings suggest an impairment in the receptiveness of the ganglion cells or demyelination of the optic nerve fibers.

Adult↗
PubMed1980

Congenital defects of the central nervous system and occupational factors during pregnancy. A case-referent study.

The possible impact of occupational factors on the furtherance of congenital defects has been under study at our department for the past four years, and it has assumed a special interest because of the importance to understand the etiology of these disorders and a good possibility for prevention by elimination of the causative factor from the work environment. In connection with a register based case-referent study utilizing supplementary information, acquired by a single interviewer, we analyzed various occupational factors related to pregnancy. We found that organic solvent exposure and exposure to various dusts during the pregnant period were more common among the case mothers than among their matched referents. These findings may offer further rough guidance in the quest for the identification of possibly embryotoxic agents that may occur in occupational life.

Abnormalities, Drug-Induced↗
PubMed1980

Application of mathematical modelling for assessing the biological half-times of chromium and nickel in field studies.

The biological half-times of urinary chromium and nickel excretion and plasma nickel concentration were calculated for four welders and four electroplaters. A linear one-compartment kinetic model gave estimates of the half-times ranging from 15 to 41 hours for chromium in urine, from 17 to 39 hours for nickel in urine, and from 20 to 34 hours for nickel in plasma. The model allows a precise description to be made of a worker's state of exposure as affected by a varying concentration of the metals in the air.

Adult↗
PubMed1980

Statistical modeling of epidemiologic data.

The application of statistical modeling to epidemiology may help suggest a form for the mechanism of exposure action. But distinguishing between the entertained biological models is often difficult due to both inadequacies in epidemiologic studies and inaccuracies in the verbal specifications of the hypothesized interaction mechanisms. For example, the independent and interactive effects of asbestos and smoking on the production of lung cancer have not yet been fully established. In the present communication an analysis of illustrative data from a hypothetical case-compeer study was attempted with the estimation of rate ratios and the use of a log-linear model fitting technique. These analyses allow a parametric representation of the testable models. For adequate material they might provide tentative insight as to whether the data would conform more closely to an additive model than to a multiplicative one or to some other advocated pattern of action.

Asbestosis↗
PubMed1980

Circadian variation of physiological functions related to physical work capacity.

The circadian variation of selected physiological functions related to physical work capacity was studied in four trained young male subjects. The twofold objective was to describe, in parametric terms, the variation of these functions and estimate the times and values of their maximum and minimum responses. Statistically significant periodic regression effects were found for the following functions: oral temperature; systolic blood pressure; heart rate at rest, during work (245 and 270 W) and after a 5-min recovery; ratings of perceived exertion; strength of hand grip; and neuromuscular coordination measured with a seesaw board balance test. The Fourier curve (sine curve) accounted for 63 % of the variation in oral temperature and from 13 to 38 % of the variation in the other significant harmonic intensities. In phase with the rhythm of oral temperature, but with larger amplitude, were systolic blood pressure, heart rate at rest and heart rate during work; roughly in phase were strength of hand grip and neuromuscular coordination. Ratings of perceived exertion and heart rate after a 5-min recovery showed a rhythm which was out of phase with the oral temperature. The number of disturbances in neuromuscular coordination was greatest at 2400 and smallest at 1200, the difference being as large as 44 %. The results suggest that the measured capacities of muscle strength and neuromuscular coordination are the lowest, that physical work is perceived as the heaviest, and recovery after work is the slowest at night. These findings appear to support the notion that performance capacity is reduced during the night.

Adult↗
PubMed1979

Immunization with major outer membrane proteins in experimental salmonellosis of mice.

Porin (outer membrane protein) preparations extracted from a rough (Rb2) mutant of Salmonella typhimurium proved to be good immunogens in mice and rabbits. The antibody response achieved was measured by using enzyme-linked immunosorbent assay techniques. High titers of both antiporin and antilipopolysaccharide were detected in both species. The rabbit antiserum raised against the porins and the porin preparations themselves had a highly significant protective capacity against intraperitoneal Salmonella infection of mice. Absorption of the rabbit antiporin serum with lipopolysaccharide immunosorbent did not change its protective capacity in a passive immunization experiment, suggesting that the antiporin antibody preparations were the active components.

Animals↗
PubMed1979

Artificial Salmonella vaccines: O-antigenic oligosaccharide-protein conjugates induce protection against infection with Salmonella typhimurium.

Outbred mice were vaccinated with various artificial Salmonella vaccines and subsequently challenged intraperitoneally with graded doses of virulent Salmonella typhimurium. The Salmonella vaccines used were: (i) octasaccharide, obtained by hydrolysis of the O-antigenic polysaccharide chain of S. typhimurium strain SH 4809 with phage P22-associated endo-rhamnosidase and covalently linked to either diphtheria toxin or edestine; (ii) purified outer membrane proteins (porins) from S. typhimurium; and (iii) octasaccharide covalently linked to porins. All vaccines induced significant protection against experimental infection of mice with S. typhimurium. However, vaccination with the octasaccharide-porin conjugate resulted in better protection than that obtained by vaccination with octasaccharide or porin vaccines separately. Rabbit antibodies raised against the different vaccines were also passively administered intravenously to mice. Such mice were protected against challenge with virulent S. typhimurium by antibodies specific for the S. typhimurium O-antigen or for the porins. Thus, active immunization with more than one surface component of Salmonella bacteria improved the efficacy of the vaccine. The data from the passive immunization experiments also emphasized the role of humoral immunity for protection against S. typhimurium infection.

Animals↗
PubMed1979

Mutants defective in the 33K outer membrane protein of Salmonella typhimurium.

Salmonella typhimurium LT2 lines, if phenotypically rough, are fully sensitive to bacteriocin 4-59, produced by Salmonella canastel strain SL1712. Bacteriocin-resistant mutants fell into three classes. Those resistant to phage ES18 and to albomycin proved to be mutants of class chr (equivalent to tonB of Escherichia coli); these mutants still adsorb the bacteriocin and so are classified as tolerant. Another class of (incompletely) tolerant mutants was resistant to phage PH51; their envelope fractions lacked the band corresponding to outer membrane protein 34K, known to serve for adsorption of phage PH51. A third class of mutants, which did not adsorb the bacteriocin, was unaltered in sensitivity to phages. Their envelopes lacked the 33K band, indicating absence of the outer membrane protein 33K, considered to correspond to outer membrane protein II* of E. coli, which in that species is determined at locus ompA (formerly tolG or con). Phage P22 HT105/1 cotransduced the 33K S. typhimurium gene (to be called ompA, to accord with E. coli usage) with pyrD+ at about 30% frequency when the donor allele was ompA+ or one ompA, but at only 3 to 11% when the donor allele was another ompA. When the donor carried either of two long deletions of the put (proline utilization) operon, phage P22 HT105/1 cotransduced put (and ompA+) with pyrD+ at low frequency. The cotransduction data indicate that ompA of S. typhimurium is located between pyrD and put, nearer the former. This corresponds to the map position of ompA in E. coli K-12.

Bacterial Proteins↗
PubMed1979

Ten-year coronary mortality of workers exposed to carbon disulfide.

Two cohorts, one comprising 343 viscose rayon workers exposed for at least five years to carbon disulfide (CS2) and the other made up of 343 nonexposed men, were followed from 1967 to 1977 with respect to coronary heart disease (CHD) mortality. In the examination in 1967 known risk factors of CHD were controlled; only blood pressure was slightly higher in the exposed group. The difference was considered a result of exposure. Five exposed and eight nonexposed men had experienced a previous clinical myocardial infarction. The total mortality was 48 (14%) in the exposed group and 31 (9%) in the compeer group (p congruent to 0.05); 29 exposed and 11 nonexposed men had died from CHD (p less than 0.01), and 5 exposed and 1 nonexposed from other cardiovascular causes (p = 0.1). All coronary deaths occurred in the age interval 40 to 69 years. The estimated risk of death from CHD for this 30-year age span, assuming no competing risks of death, was 31.9% for the exposed cohort against 13.3% for the compeers. A multivariate analysis yielded age, raised blood pressure, and exposure to CS2 as prominent risk factors. The contributory risk caused by past occupational CS2 exposure seemed to increase the already notoriously high risk of CHD mortality among Finnish men.

Adult↗