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Biomedical subjects

C Andreasen

Publications and source records attributed to C Andreasen.

7 recordsLinked to original sources

Trends in mercury in hair of Greenlandic polar bears (Ursus maritimus) during 1892-2001.

Mercury concentrations in hair from 397 Greenland polar bears (Ursusmaritimus) sampled between 1892 and 2001 were analyzed for temporal trends. In East Greenland the concentrations showed a significant (p < 0.0001, n = 27) increase of 3.1%/year in the period 1892-1973. In Northwest Greenland, a similar (p < 0.0001, n = 69) increase of 2.1%/year was found, which continued until 1991, when the most recent samples were obtained. In East Greenland, a significant (p = 0.009, n = 322) decrease of 0.8%/year was observed after 1973. Two Northwest Greenland samples from 1300 A.D. had a mean value of 0.52 mg/kg of dry weight, which can be considered as a baseline level. The Hg concentration during 1985-1991 from Northwest Greenland (mean value of 7.45 mg/kg of dry weight) was more than 14-fold higher than the assumed baseline level from 1300 A.D. from the same region (i.e., about 93% anthropogenic). Although a decrease was found in East Greenland after 1973, the concentration is still ca. 11-fold higher than the baseline level (i.e., about 90% anthropogenic).

Animals↗

Outbreak of leptospirosis associated with swimming.

Between July 7 and 18, 1991, five boys from a small town in rural Illinois experienced the onset of an acute febrile illness subsequently confirmed as leptospirosis by serologic tests. A cohort study found that swimming in a small swimming hole, Steel Tunnel Pond, was associated with disease (P < 0.01), the attack rate being 28%. Leptospira interrogans serovar grippotyphosa was isolated from urine cultures from two of the case patients and from a culture of Steel Tunnel Pond water. A high seroprevalence for grippotyphosa was found in animals near the pond. Drought conditions had been present in the month before the outbreak, creating an environment in the pond which probably facilitated transmission of the organism from area animals to humans. Although leptospirosis is infrequently reported in humans in the United States, it is endemic in animals and the potential for outbreaks exists, especially when environmental conditions are favorable.

Adolescent↗

Epidemiology of abnormal liver function tests in general practice in a defined population in Denmark.

It is common for general practitioners (GPs) to refer patients suspected of impaired liver function for laboratory tests (alkaline phosphatase, lactate dehydrogenase, bilirubin, prothrombin, aspartate aminotransferase). In a prospective multipractice study over a six-month period, including 30 GPs, 55 patients were recorded as having, for the first time, a high level of alkaline phosphatase (AP) as an isolated finding, 14 with an increase of aspartate aminotransferase (ASAT), eight with an increase of both AP and ASAT, three with an increase of ASAT, AP, and bilirubin, two with an isolated increase of lactate dehydrogenase (LDH), one with an increase of ASAT, AP, and bilirubin, combined with a low prothrombin (PP), and, finally, one patient with a low prothrombin in isolation. In most cases the tests were requested because of unspecific symptoms. The most common causes of abnormal test results were neoplasms, alcoholic liver disease, and heart failure. Thirty patients were referred to hospital for further investigations. During the same study period, 50 patients with known abnormal liver function tests were recorded, and the most common causes of these abnormalities were neoplasms, rheumatoid arthritis, and alcoholic liver disease.

Aged↗

A prospective multipractice study based on antecedent data. Reduced selection and behaviour bias.

A prospective multipractice study based on well-defined data collected by a number of general practitioners (GPs) over a period of time is often used in primary health care research. However, problems of research methodology such as selection bias are common in such studies when GPs either refuse to participate or interrupt their participation. A method is described whereby selection bias is avoided. In the present study, a medical laboratory made a daily record of all abnormal liver function tests requested by GPs over a period of six months. When mailing these results to the GPs, a questionnaire was enclosed in order to obtain a number of clinical data from them. Thirty of 31 possible GPs participated. During the study period, questionnaires concerning 134 patients were mailed, and 118 of these were returned without reminders. Following one reminder the response rate was 100%. Comparing the number of requested tests during the study period with the number requested during a control period before and after the study period (same six month periods of the year), no difference was seen in the pattern of requests. Thus, this method, unbiased with respect to both selection and request-behaviour, is recommended for similar studies.

Denmark↗