The incidence and distribution of risk factors in non-pregnant women diagnosed with deep vein thrombosis is not well known and was the target of the present study. The medical records of 102 non-pregnant women aged 15-44 hospitalized with deep vein thrombosis at two major Norwegian hospitals were examined retrospectively. The overall incidence of first event of deep vein thrombosis remained fairly constant over the 10-year study period and was estimated at 10.5 per 100,000 women-years. The incidence increased with age and was found twice as high for women 35-44 years of age when compared with the 15-34 age group. Forty-three (42%) of the patients had no identifiable risk factors. Surgery or trauma was found in 37 (36%) of the patients, eight (8%) had a diagnosis of associated cancer, and five (5%) were drug addicts. Five of eight patients registered with immobilization had immobilizing chronic neurological diseases. Thirty-nine (38%) of the patients used oral contraceptives at the time of diagnosis, and 14 of the 39 users of oral contraceptives were identified with medical risk factors. Over the 10-year study period there was no change in the incidence of venous thromboembolism and the risk profile among cases remained constant.
Sexual selection can be affected by the competition for limited breeding resources and/or the competition for limited mates. Although there is ample evidence for each type of competition by itself, little is known about their relative importance and interaction. To address these questions, we established 48 experimental breeding populations of the two-spotted goby (Gobiusculus flavescens), a substrate-breeding fish with paternal care. In three experimental treatments, males were limited in the access to either nest sites or mates or were provided with both nests and mates in excess. We quantified male competition behaviour (agonistic and courtship), the opportunity for selection and selection on male body size. Limited access to nests and mates produced similar opportunities for selection, but only limited access to mates increased male competitive behaviours and caused positive selection on male body size. Selection on body size in the mate-limited treatment was due both to larger males being more likely to take up nests and to larger males being more likely to mate once they had a nest. These findings demonstrate that resource and mate limitation can differ in their effects on sexual selection. The results also reveal that resource and mating competition can be highly inter-related and not always separated in time, implying that methods to disentangle the two processes must be chosen with care. Future research should consider experimental and analytical approaches similar to those of the present study in attempts to elucidate the interaction of resource and mating competition in animals.
This study focuses on the incidence and risk profile among young women with a diagnosis of pulmonary embolism over the 10-year period 1988-97. A total of 66 non-pregnant women aged 15-44, treated for the first event of pulmonary embolism, were identified by discharge diagnosis at two main Norwegian hospitals (The Regional Hospital of Trondheim and Ullevål Hospital, Oslo). The estimated overall incidence of pulmonary embolism was 6.8 per 100,000 women-years. The crude incidence decreased from 7.5 per 100,000 women-years in 1988-90 to 4.1 per 100,000 women-years in 1996-97 (p
This article reports on a retrospective study in two major Norwegian hospitals of spontaneous reporting to the Adverse Drug Reaction Committee of the Norwegian Medicines Control Agency of adverse reactions from the use of oral contraceptives (OCs) among patients with a diagnosis of venous thromboembolism. In these two hospitals, 168 women between 15 and 44 were diagnosed with a first event of venous thromboembolism during the ten-year period up to the end og 1997; 69 of them were OC users at the time of diagnosis. Three medical records (4%) kept at the hospital contained information on a report of adverse drug reaction to the Norwegian Medicines Control Agency. The Agency's database of all spontaneous reports on adverse drug reactions contains 112 reports of venous thromboembolism in the context of OC use. These reports came from all over Norway during the ten-year period of our study; four of the reports came from the study hospitals. We conclude that venous thromboembolism during the use of OCs was underreported by more than 90%. This corresponds to estimates of underreporting of other adverse drug reactions from the use of various compounds, in Norway as well as in other countries.
Genetic parentage analyses reveal considerable diversity in alternative reproductive behaviours (e.g. sneaking) in many taxa. However, little is known about whether these behaviours vary seasonally and between populations. Here, we investigate seasonal variation in male reproductive behaviours in a population of two-spotted gobies (Gobiusculus flavescens) in Norway. Male two-spotted gobies guard nests, attract females and care for fertilized eggs. We collected clutches and nest-guarding males early and late in the breeding season in artificial nests and used microsatellite markers to reconstruct parentage from a subset of offspring from each nest. We hypothesized that mating, reproductive success and sneaking should be more prevalent early in the breeding season when competition for mates among males is predicted to be higher. However, parentage analyses revealed similar values of mating, reproductive success and high frequencies of successful sneaking early (30% of nests) and late (27% of nests) in the season. We also found that multiple females with eggs in the same nest were fertilized by one or more sneaker males, indicating that some males in this population engage in a satellite strategy. We contrast our results to previous work that demonstrates low levels of cuckoldry in a population in Sweden. Our results demonstrate marked stability in both the genetic mating system and male alternative reproductive tactics over the breeding season. However, sneaking rates may vary geographically within a species, likely due to local selection influencing ecological factors encountered at different locations.