Beryllium atom reinvestigated: A comparison between theory and experiment.
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Biomedical subjects
Publications and source records attributed to J Olsen.
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In a prospective study conducted on the island of Guernsey a cohort of 5162 ostensibly healthy women was enrolled between 1967 and 1976. Blood samples were drawn from each participant, who also completed a questionnaire, which provided information on established risk indicators in human mammary carcinogenesis. Plasma selenium levels were measured in 46 breast cancer cases diagnosed a mean of 11 (S.D. 4) years after entry into the study cohort and in an age-stratified sample of 138 women drawn from the study base. Plasma selenium level in the cases was 109 (28) micrograms/l and in the base sample 103 (22) micrograms/l (95% confidence interval for the overall difference, -2 to 14 micrograms/l). The adjusted relative risk of developing breast cancer in the different quartiles of the selenium distribution was 0.80, 0.79, 0.72 and 1.00, respectively. Thus, in the present study selenium was not a strong indicator of human breast cancer risk.
The hypothesis of the study was that social contacts to close friends and relatives and perceived social integration was able to delay mortality in general and cardiovascular mortality in particular. Altogether 1752 males and females, aged 70-100 years were interviewed by trained nurses in 1972 to 1974. The study group was based upon a random sample of all elderly in the town of Odense, Denmark. More than 80% participated in the survey which included data collection on social networks and health at the time of interviewing. By means of linking the study group to national registries on mortality and causes of mortality practically all in the cohort were traced until 1987. During follow-up 1501 persons died. Most of the association between social networks and mortality were weak and statistically insignificant but had the expected sign. After adjusting for initial health status only the interviewer's assessment of the quality of the network was statistically significant associated with longevity. A feeling of loneliness was found to be associated with cardiovascular mortality, especially for males.
We studied the effect of coffee consumption on birthweight, preterm births, and congenital malformations. From April 1985 to April 1987, 11,858 pregnant women out of 13,815 in two Danish cities responded to a mailed questionnaire on eating and drinking habits during pregnancy. Data on pregnancy outcomes were recorded from medical files. Maternal coffee consumption of four cups a day or more was associated with a moderate decrease in birthweight, especially among smokers. The associations between coffee consumption and preterm births or congenital malformations were very weak.
Urethral strictures induced by the use of latex catheters and combined silicone/latex catheters following open-heart surgery have been reported. These strictures differ from the post-catheterisation type in affecting a greater length of urethra. Recently it was shown that complement was activated by catheters which cause inflammation, in contrast to clinically silent catheters. The present study was designed to investigate a possible association between catheter-induced inflammation and activation of another mediator of inflammation, the contact system. We also investigated various in vitro conditions to optimise biocompatibility studies. Our data indicate that both the complement and the kallikrein-kinin system are activated by potentially harmful silicone/latex catheters and may be involved in the pathophysiology of catheter-induced urethral strictures. In vitro biocompatibility tests may be performed at both 20 and 37 degrees C. Glass test tubes may be used for in vitro complement but not for kallikrein-kinin investigations.
An interobserver analysis of the reproducibility of malignancy grade and of histological type classified according to World Health Organization criteria was performed in 261 ovarian tumours, stages IIB to IV. All available slides per patient including metastatic tumours (16%) were reviewed independently by two pathologists. Overall observed agreement regarding type was 68%. The chance-corrected agreement expressed by the kappa coefficient was 0.55 (95% confidence interval 0.49-0.61). Overall observed agreement regarding grade was 41% compared with a kappa coefficient of 0.19 (95% confidence interval 0.12-0.26). Kappa coefficients, ranging from 0.18 to -1.00 for associations between type categories and from 0.20 to -0.32 for grade categories, indicated that any suggested pattern of association could be caused by chance occurrences. A more objective approach to histopathology is needed in ovarian carcinoma before its prognostic impact can be assessed.
STUDY OBJECTIVE: The aim was to investigate whether specific types of work or exposures among pharmacy assistants were correlated with changes in birth weight or gestational age. DESIGN: The study was a nationwide historical cohort with open entry of all female members of the union of pharmacy assistants during 1979 to 1984. PARTICIPANTS: The cohort comprised 4939 pharmacy assistants under 40 years of age. The questionnaire was answered by 93%. MEASUREMENTS AND MAIN RESULTS: Information on birth weight and gestational age was obtained by linkage to the national birth register. Exposure information on type of work and exposure to pharmaceutical and chemical products during pregnancy was self reported. Only small and non-significant differences in birth weight and gestational age were found between the compared groups. Mean birth weight was 50 g above the national mean and gestational age was longer (p less than 0.0005). CONCLUSIONS: Compared to the Danish population, children of pharmacy assistants are at low risk for experiencing low birth weight and preterm birth. Social status and less smoking during pregnancy among pharmacy assistants might explain the slightly greater mean birthweight and gestational age in this sector of the population.
The porcine aminopeptidase N (PEPN) gene was shown to be syntenic with the porcine major histocompatibility complex (SLA) using Southern blot analysis of a pig x mouse hybrid cell panel. Regional localization of the PEPN gene to 7cen----q21 was performed by in situ hybridization. The results suggest that synteny of the genes for mannose phosphate isomerase and PEPN is conserved in pig and man.
Adjustment for multiple confounding is usually done by applying some kind of regression model. This requires assumptions about the type of relationship between the exposure of interest and outcome. It has been suggested to use confounder scores within strata of which the relationship can be scrutinised without such assumptions. Adjusting continuous outcomes for confounding factors, like birth weight for gestational age and lung function measures for age, is sometimes done by using the ratio of the observed outcome to an outcome expected from a reference series external to the study, with a concomitant risk of introducing new confounding. In some cases, the ideas from both these approaches can, slightly modified, be successfully combined. By using an internal rather than an external reference series, i.e. a group within the data with constant exposure, expected values for outcome can be derived as the fitted values from some model, appropriate for the purpose, depicting outcome conditional on all the potential confounders that are registered and for which control is desired. The relationship between the exposure of interest and the outcome, now represented by the fractional departure for each individual from the value expected conditional on her/his confounder status, can be scrutinised without any assumptions about the form of this relationship but, contrary to the confounder score approach, on the basis of the entire data set. This method also provides a way of presenting the relationship of interest, adjusted for confounding, that is easier to understand than the traditional regression approach. The impact of alcohol intake during pregnancy on birth weight will be given as an example.
Clinical data from 218 patients consecutively treated for nasopharyngeal carcinoma at the Finsen Institute in Copenhagen during the period 1965 through 1985 have been analyzed for factors of prognostic importance. Of the 218 patients, 47 were Greenland Inuit eskimos and 169 were white Danish. The 5-year crude survival for the entire group of patients was 30%. The two groups of patients differed with respect to the importance of different prognostic factors. Keratinizing tumors were only present in the Danish population. These patients had a highly significant worse outcome than the rest of the Danish (P less than 0.00001). Age, stage, and T classification were important prognostic factors in the Danish population, but not in the Inuit population.
Smoking and drinking habits were registered by a self-administered questionnaire in 36th week of gestation in 11,698 pregnant women, more than 80 percent of all such women in two Danish cities 1984-87. Alcohol consumption of 120 g/week or more was associated with a greater reduction in the average birthweight in the babies of smokers than of non-smokers (about 40 grams for the non-smokers and about 200 grams for the smokers). This is particularly striking considering that the average birthweight for smokers is lower than for non-smokers. A birthweight difference of more than 500 grams was found between babies of mothers who neither smoked nor drank and mothers who smoked and drank heavily. Our data suggest that women's smoking habits should be taken into consideration when giving pregnant women advice about drinking.
The aim of this case-referent study was to investigate reproductive hazards other than congenital malformations after exposure to high-frequency electromagnetic radiation. Cases and referents were sampled from a cohort of pregnancies of members of the Union of Danish Physiotherapists through linkage of the union file with national medical registers. Case groups were spontaneous abortions and children with low birth-weight prematurity, and stillbirth/death within one year. Exposure to high-frequency electromagnetic radiation before and during pregnancy was assessed through telephone interviews. As referents to the 270 cases, 316 pregnancies were randomly sampled. A total of 8.4% did not participate. Only 23.5% of the children born by the highly exposed mothers were boys. This value is a statistically significantly altered gender ratio showing a dose-response pattern. High-frequency electromagnetic radiation was furthermore associated with low birthweight, but only for male newborns. The other outcomes were not statistically significantly associated with exposure to high-frequency electromagnetic radiation.
A 133Xe washout technique for measuring the blood flow in the intestinal mucosa is introduced and evaluated. In 11 anaesthetized pigs a laparotomy was performed and the mucosal blood flow rate in the intestine of the pig was determined by a local epimucosal application of 133Xe. In both the colon and the small intestine the 133Xe washout plotted in a semilogarithmic diagram showed a multiexponential configuration. Histological examination and localization studies showed shunting by diffusion of 133Xe in the intestinal mucosa explaining the multiexponential configuration of the washout curve. Therefore the initial slope of the washout was used for measuring blood flow rate. Blood flow rate was simultaneously measured by microsphere entrapment technique. There was an excellent correlation between the blood flow rate determined by the two techniques the correlation coefficient R being 0.89 in the small intestine and 0.996 in the colon.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.