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Biomedical subjects

J Olsen

Publications and source records attributed to J Olsen.

At least 217 records · Page 12Linked to original sources
PubMed1998

Fecundability of female twins.

Animal studies have shown evidence of prenatal hormonal interaction between unlike sexed fetuses, including reduced fertility among females. We evaluated whether the fecundability of female twins is different from that of singletons and whether it differs according to the sex of the co-twin. The study was based on a questionnaire survey of 12,681 female twins born in the period 1953-1976 and an interview survey of 760 female controls born in the period 1953-1966, both in Denmark. Outcome of the first try ever to become pregnant (pregnant, still trying, stopped trying, pregnant despite contraception, and never tried) and the waiting time to pregnancy distribution did not differ among monozygotic, dizygotic same sexed, and dizygotic unlike sexed twins. More twins had a waiting time of less than 2 months, compared with singletons. This difference probably reflects an artifact due to the data collection method, because it disappeared when the cutoff point was changed to include 2 months for singletons, and we found no difference for longer waiting times. Hence, we found no increase in fecundability for twins compared with singletons, nor any reduced fecundability among female twins from unlike sexed pairs.

Adolescent↗
PubMed1998

The cumulative incidence of venous thromboembolism during pregnancy and puerperium--an 11 year Danish population-based study of 63,300 pregnancies.

OBJECTIVES: The aim of the study was to estimate the cumulative incidence of venous thromboembolism during pregnancy and the puerperium. METHODS: All diagnoses concerning venous thromboembolism in the Hospital Discharge Registry from a Danish County in women less than 49 years of age from 1984 to 1994 were included. The number of deliveries in the County during this period was obtained from The Medical Registry of Birth. RESULTS: The cumulative incidence of venous thromboembolism during pregnancy and puerperium was 0.85 (95% CI: 0.64-1.11) per 1000 deliveries. The cumulative incidence was 0.49 (95% CI: 0.28-04).80) in 1984-89 but increased to 1.23 (95% CI: 0.87-1.69) after the introduction of ultrasound. CONCLUSION: The risk of diagnosed venous thromboembolism is low but estimates of the incidence are probably procedure dependent.

Denmark↗
PubMed1998

The Danish Medical Birth Registry.

BACKGROUND: The Danish Medical Birth Registry (MBR) was established in 1968 and has been computerized since 1973. The primary purpose of the registration is to monitor the health of the newborns and of the quality of the antenatal and delivery care services, but the registry is increasingly being used in research. Major changes in registration have taken place in 1978 and 1991. The paper describes the content and usage of the MBR over time and suggests research topics for the future. RESULTS: A broad scope of studies illustrates how the MBR has been used, either as single data source, linked with data from other registries or with data from interviews or self-completed questionnaires. Validations have shown variations in the quality of data, depending on source, and have underlined the need for constant quality control. Any access to data at the individual level is subjected to special provisions laid down by the Data Surveillance Authority and also requires a permission from the National Board of Health. CONCLUSIONS: The time from conception to early childhood is an important period concerning future health for the individual. The Danish Medical Birth Registry is a valuable tool in this respect, which has not yet been used to its full potential in research or monitoring. Experience indicates that the quality of the registry depends upon having a close link to the staff responsible for delivery services and thus having the necessary specialised skills and interest.

Data Interpretation, Statistical↗
PubMed1997

Change in social status and risk of low birth weight in Denmark: population based cohort study.

OBJECTIVE: To estimate the risk of having a low birthweight infant associated with changes in social, environmental, and genetic factors. DESIGN: Population based, historical cohort study using the Danish medical birth registry and Statistic Denmark's fertility database. SUBJECTS: All women who had a low birthweight infant (< 2500 g) (index birth) and a subsequent liveborn infant (outcome birth) in Denmark between 1980 and 1992 (exposed cohort, n = 11,069) and a random sample of the population who gave birth to an infant weighing > or = 2500 g and to a subsequent liveborn infant (unexposed cohort, n = 10,211). MAIN OUTCOME MEASURES: Risk of having a low birthweight infant in the outcome birth as a function of changes in male partner, area of residence, type of job, and social status between the two births. RESULTS: Women in the exposed cohort showed a high risk (18.5%) of having a subsequent low birthweight infant while women in the unexposed cohort had a risk of 2.8%. After adjustment for initial social status, a decline in social status increased the absolute risk of having a low birthweight infant by about 5% in both cohorts, though this was significant only in the unexposed cohort. Change of male partner did not modify the risk of low birth weight in either cohort. CONCLUSION: Having had a low birthweight infant and a decline in social status are strong risk factors for having a low birthweight infant subsequently.

Adult↗
PubMed1997

[Sensible drinking limits].

A large number of prospective population studies from many countries have described a J- or U-shaped relation between alcohol intake and mortality. Both heavy drinkers and abstainers are at a higher risk of dying from all causes than individuals with light to moderate alcohol intake. This makes information to the public about sensible drinking limits more complex than, eg, that concerning smoking. The present paper aims at identifying upper thresholds for harmless alcohol intake. The review is mainly based on epidemiological evidence concerning somatic morbidity and mortality. It is concluded that the present Danish recommendations--14 drinks per week for women and 21 drinks per week for men--should be maintained. It is emphasized that these limits apply to adults who are at no risk of dependency and that they do not apply to pregnant women. Information about a potentially beneficial effect of a moderate alcohol intake should be reserved for individuals already at risk of coronary events.

Adult↗
PubMed1997

Birth weight and cognitive function in young adult life: historical cohort study.

OBJECTIVE: To examine the relation between birth weight and cognitive function in young adult life. DESIGN: Retrospective cohort study based on birth registry data and cognitive function measured during evaluation for military service. SUBJECTS: 4300 Danish conscripts born between 1973 and 1975. MAIN OUTCOME MEASURES: Mean score in the Boerge Prien test of cognitive function; score is the number of correct answers to 78 questions and correlates with full scale intelligence quotient (IQ). RESULTS: Mean score in the Boerge Prien test increased from 39.9 at a birth weight of < or = 2500 g to 44.6 at a birth weight of 4200 g even after adjustment for gestational age and length at birth, maternal age and parity, and other variables. Above a birth weight of 4200 g the test score decreased slightly. CONCLUSION: Birth weight is associated with cognitive performance in young adult life. Interference with fetal growth may influence adult cognitive performance.

Adolescent↗
PubMed1997

[Randomized population study of screening for intestinal cancer with Hemoccult-II].

The aim of the randomised study was to compare mortality rates from colorectal cancer (CRC) in persons screened with faecal occult-blood tests every two years during a 10-year period with those of unscreened similar controls. Thirty thousand nine hundred and sixty-seven persons aged 45-75 years in 1985 were allocated to screening and another 30,966 to a control group. Only participants who completed the first round with Hemoccult-II were invited for further screening. Participants with positive tests were offered colonoscopy. The primary endpoint was death from CRC. Sixty-seven percent completed the first screening round, and of these more than 90% accepted repeated screenings. During the 10 year study, 481 persons in the screening group had a diagnosis of CRC, compared with 483 unscreened controls. CRC mortality was significantly lower in the screening group (205 deaths) than in controls (249 deaths) (mortality ratio 0.82 [95% conf. lim. 0.68-0.99], p = 0.03). Our findings indicate that biennial screening by faecal occult-blood tests can reduce CRC mortality.

Adenoma↗
PubMed1997

[Smoking reduces the biological capacity of conception. Results from a European multicenter study. The European Study Group on Infertility and Subfecundity].

The aim of the study was to examine the impact on subfecundity of male and female smoking at the start of a couple's waiting time to a planned pregnancy. Two types of designs were applied: a population based sample of women aged 25-44 years of age and a consecutive sample of pregnant women. Both studies were conducted within well-defined geographical regions in a number of European countries and data were collected by personal interviews in the population-based sample and by interview or self-administered questionnaires in the pregnancy study. A total of 10,665 couples participated in the study. Data on possible risk factors for infertility and subfecundity were collected at the start of the pregnancy planning, and fecundity was estimated by using time from the beginning of unprotected intercourse to a pregnancy, which survived at least 20 gestational weeks. Only couples who planned a pregnancy were included in the analyses. The results showed remarkably coherent associations between female smoking and subfecundity in each individual country and in all countries put together. In the population sample the odds ratio for subfecundity in the first pregnancy was 1.7 (95% c.l. 1.3-2.1 at the upper level of tobacco consumption) and during the most recent waiting time to pregnancy the odds ratio was 1.6 (95% c.l. 1.3-2.1). Results based on the pregnancy sample were similar with an odds ratio of 1.7 (95% c.l. 1.3-2.3). No significant association was found between male smoking and the couple's fecundity.

Adult↗
PubMed1997

Randomised trial of effect of vitamin A supplementation on antibody response to measles vaccine in Guinea-Bissau, west Africa.

BACKGROUND: WHO has recommended vitamin A supplementation for children aged 6 months or older in developing countries at the same time as immunisation. One study has reported significantly lower seroconversion ratios among children who have received vitamin A supplements with measles vaccine at age 6 months. The aim of our study was to assess the effect of vitamin A supplementation on antibody response to measles vaccination at age 9 months, which is the more common age for immunisation in developing countries. METHODS: In an urban community in Guinea-Bissau, we did a randomised, double-blind, placebo-controlled study of the effect of simultaneous vaccination and vitamin A supplementation in 462 children who received either a two-dose schedule of measles vaccine at the ages of 6 months and 9 months (150 infants) or one dose of measles vaccine at age 9 months (312 infants). Children were followed up to the age of 18 months and a blood sample was then collected to assess the antibody response. FINDINGS: 397 (86%) of the children took part in the follow-up (52 [11%] had moved and 13 [3%] had died). Among children who received a two-dose vaccine schedule, seroconversion was 98%. There was no difference in seroconversion or geometric mean titre (GMT) for children receiving vitamin A compared with children receiving no supplement. Among children receiving only one dose of measles vaccine at age 9 months, seroconversion was 95%. The GMT was significantly higher in children receiving vitamin A than in those receiving no supplement (3704 vs 2439 mIU; GMT ratio 1.52 [1.22-1.88]). The effect on plasma antibody concentration in the blood was stronger for boys (3902 vs 1916 mIU; GMT ratio 2.04 [1.53-2.72]) than for girls (3502 vs 3017 mIU; GMT ratio 1.16 [0.85-1.58]) who had received vitamin A with measles vaccine. In a multivariate analysis of variance adjusted for sex, vitamin A supplementation was associated with higher antibody titres (p < 0.001). There was a significant interaction between vitamin A supplementation and sex (p = 0.02). INTERPRETATION: There is no indication that simultaneous administration of measles vaccine and vitamin A supplements has a negative effect on measles immunity. Among the children who had received two doses of measles vaccine at the ages of 6 months and 9 months, supplements of vitamin A had no significant effect. Among children only receiving one dose of measles vaccine at age 9 months, 100,000 IU vitamin A increased antibody concentrations, especially for boys.

Antibodies, Viral↗
PubMed1997

An enhancer with cell-type dependent activity is located between the myeloid and epithelial aminopeptidase N (CD 13) promoters.

The 5' flanking region of the gene encoding the small intestinal brush-border peptidase aminopeptidase N (APN) was screened for the presence of enhancer regions. A 300 bp region with enhancer activity was identified 2.7 kb upstream of the transcriptional start site which is used in epithelial cells. The enhancer stimulated transcription from a heterologous promoter (the simian virus 40 early promoter) in a position- and orientation-independent manner. The activity of the enhancer is cell-type dependent and it is active in liver (HepG2), intestinal (Caco-2) and myeloid (K562) cells. As the epithelial APN promoter is active in the first two cell-types and the myeloid APN promoter in the last, the results may suggest that the enhancer, through a cooperation with either of the promoters, is important for the tissue-specific expression of APN. A detailed analysis of the enhancer led to the identification of four functionally important regions that are protected against DNase I digestion by Caco-2 nuclear extract. Sequence analysis suggests that two of the regions may interact with members of the Ets transcription factor family (Ets is a transformation-specific protein first discovered in the E26 avian erythroblastosis virus), one region with a CCAAT enhancer-binding protein and one region with Sp1, a transcriptional activator first described as a factor binding to the simian virus 40 early promoter.

Base Sequence↗
PubMed1997

Nicotine patches in smoking cessation: a randomized trial among over-the-counter customers in Denmark.

The authors examined the effect of 24-hour nicotine patches in smoking cessation among over-the-counter customers in Denmark, based on a randomized double-blind placebo-controlled trial. Participants were consecutive customers to whom nicotine patches were offered as the only treatment. Forty-two pharmacies in the areas of Aarhus and Copenhagen in Denmark participated in the trial, and 522 customers who smoked 10 or more cigarettes per day were randomized to either nicotine patches or placebo from January to March 1994. Customers with chronic diseases and pregnant or breastfeeding women were excluded from the trial. Twenty-four-hour patches were offered free of charge during a 3-month period. Those smoking 20 or more cigarettes per day started on a dose of 21-mg/day patches. Customers who smoked less started on patches of 14 mg/day; and for all of the participants, the dose was gradually reduced to 7-mg/day patches during the study period. Smoking behavior and compliance were recorded by means of self-administered questionnaires and telephone interviews. Smoking status was recorded in intervals of 4 weeks, which was fixed to be a treatment period, and 26 weeks after inclusion. There was a significant increase in smoking cessation rates after 8 weeks of follow-up but only among smokers who started on 21-mg/day patches. There was a marked placebo effect at each time of contact during the trial, especially in those smoking fewer than 20 cigarettes per day. Although the noncompliance rate was high overall due to discontinuation in the use of patches by relapsed smokers, noncompliance among successful quitters was low. More side effects were seen in the nicotine group than in the placebo group, but none of the reported side effects were serious. It appears that regular healthy smokers who were customers of nonprescribed nicotine patches and who received 21-mg/day nicotine patches benefited from the active treatment (44.1% stopped smoking after 4 weeks), but almost as many stopped smoking in the placebo group (37.3% after 4 weeks). No significant differences in smoking cessation rates were seen among smokers who started with the low-dose nicotine or placebo patches.

Administration, Cutaneous↗