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Biomedical subjects

A Gottschau

Publications and source records attributed to A Gottschau.

48 records · Page 3Linked to original sources
PubMed1993

No change in incidence and prevalence of HIV among intravenous drug users in Copenhagen from 1985 to 1990.

During the years 1984 to 1990, 1,029 intravenous drug users (IVDU), equalling approximately one-third of the estimated total IVDU population in the study area, attended the outpatient venereal disease clinic of Copenhagen for an HIV antibody test. Neglecting samples on HIV-positive persons after the first positive test, 665 IVDU were only tested once, whereas 364 IVDU had 613 tests performed after their first HIV antibody negative result. HIV prevalences calculated for each year showed that the prevalence of 20% in 1985 was significantly higher than those of the following years, varying between 9% and 12% without any statistical differences between these years or evidence of an increase or a decrease. HIV incidence was calculated from the results of the 364 IVDU with an initially negative HIV test, from whom 613 subsequent test results were available and of which 20 showed HIV antibodies. The total risk period was 837 years, and the overall incidence 2.4 per 100 person years without any difference between male and female IVDU, but with a tendency of a decreasing incidence with increasing age. The incidence rates per 100 person years were 2.82 in 1984-1987 and 2.38 in 1988-1990, which is not significantly different. A seroconversion rate of 2.42 (1.51-3.65) per 100 IVDU per year was calculated. With an estimated IVDU population of 3,000 persons in Copenhagen, the yearly number of new HIV infected IVDU can then be estimated to 72 persons (45-110), a figure that is 100% higher than that known from the anonymous national HIV reporting system.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

Identification of immunodominant antigens during infection with Mycobacterium tuberculosis.

T lymphocytes isolated from mice infected with Mycobacterium tuberculosis response vigorously to proteins secreted by the bacilli and these antigens may be of importance in the generation of protective immunity against the disease. In this study, short-term culture filtrate (ST-CF), which constitutes a complex mixture of secreted proteins, was fractionated by a modified preparative SDS-PAGE technique. The ability of each fraction to be recognized by T cells isolated from infected mice was evaluated by quantifying proliferation and IFN-gamma production in cell cultures. Two molecular mass regions 4-11 and 26-35 kDa were found to possess marked stimulatory properties. Four potent single antigens were mapped within the stimulatory regions. These purified antigens stimulated T cells isolated from mice at the height of a tuberculous infection to produce large amounts of IFN-gamma. Two of these stimulatory antigens belonged to the antigen 85 complex.

Analysis of Variance↗
PubMed1992

Detection of mycobacteria from blood and bone marrow: a decade of experience.

This study reports our experience with methods used at our department from 1981 through 1990 for detection of mycobacteria in blood and bone marrow specimens. Direct inoculation on Lowenstein Jensen media was replaced by Isolator lysis-centrifugation followed by inoculation on conventional solid media, and the Bactec 12B and Bactec 13A systems. A total of 3033 specimens were analyzed. A total of 137 mycobacterial isolates were obtained from 42 patients, all HIV-positive except one. Mycobacteremia caused by M. avium-intracellulare (83%), M. tuberculosis, M. scrofulaceum and M. kansasii was found. Of 680 blood specimens tested by the last three methods, 7.6% were found to be positive by at least one method and revealed recovery rates of 6.8% for the Isolator-solid media system, 3.4% for the Isolator-12B system and 6.9% for the 13A system (all isolates MOTT). Mean detection times for 21 cultures found positive by all three methods were 23.6, 23.3 and 17.7 days for the Isolator-solid media, Isolator-12B and 13A systems, respectively, with a significantly shorter detection time for the 13A system. Low degree (less than 1 cfu/ml) mycobacteremia (MOTT) caused delay in the Isolator-solid media and the 13A systems and no detection in the Isolator-12B system. Antituberculous therapy significantly prolonged the detection times for MOTT in the 13A system in contrast to the other systems.

Bacteremia↗
PubMed1992

Exchangeability in multivariate Markov chain models.

Time-homogeneous Markov chain models with state space [0, 1]k are useful in analysis of binary follow-up data on k individuals that interact. The number of parameters increases exponentially with k so more restrictive models are imperative for statistical inference. The hypothesis that the matrix of transition probabilities is invariant under permutation of individuals is discussed. It is shown that if individuals are exchangeable, then the process counting the number of individuals occupying a given state is a Markov chain. This reduction of data is sufficient if either at most a single individual may change state between two consecutive time points or if a state is absorbing. Similar results are obtained for exchangeability within two subgroups. Inference in the multivariate process reduces to a univariate problem if individuals are independent given the group's previous response. It is shown how conditional independence could be tested assuming exchangeability. The different hypotheses re examined in an analysis of the occurrence of bacteria in milk samples of Danish dairy cattle.

Animals↗
PubMed1992

Lack of evidence of vertical transmission of human immunodeficiency virus type 2 in a sample of the general population in Bissau.

Twenty-nine human immunodeficiency virus type 2 (HIV-2) seropositive women identified in a cross-sectional study in Bissau in 1987 participated in a follow-up study in 1988, where each was matched for age and marital status with two HIV-2 seronegative women. Detailed information about all pregnancies was obtained. The HIV-2 seropositive women and their controls had similar mean numbers of pregnancies, live children, children who died, and abortions. The HIV-2 seropositive women did not have a greater risk of having had an abortion or a child who died than did the HIV-2 seronegative women. No difference in survival was seen between children born to HIV-2 seropositive and HIV-2 seronegative women. The H/S-ratios and CD4 numbers were lower in the seropositive group, but none had values lower than 0.4 and 0.4 x 10(9)/L, respectively. Seven prospectively observed children born to HIV-2 seropositive mothers showed no sign of infection. The lack of evidence of transmission of HIV-2 from mother to child is suggested to be due to the absence of marked immunodeficiency in this random sample of the general population.

Adult↗
PubMed1991

Evolution of Staphylococcus aureus resistance to erythromycin in Denmark, 1959 to 1988: comparison with erythromycin-susceptible strains.

Between 1959 and 1988, all Staphylococcus aureus strains (15 168 patients) isolated from blood in Denmark have been collected, investigated and stored, and clinical data has been obtained. Erythromycin resistance was found in 4.9% of these strains. The frequency of erythromycin resistance peaked at 25% in 1966, due to the spread in hospitals of multiresistant strains of the 83A complex. When these strains dominated, an increased mortality rate was seen in patients infected with erythromycin-resistant S. aureus. In contrast to most countries, erythromycin resistance in S. aureus declined to less than 5% in 1971, continued to fall to 1.3% in 1983, and has increased slowly to 2.4% in 1988. The decline was only due to a decrease of multiresistant strains. Erythromycin-resistant strains isolated in recent years are predominantly resistant only to penicillin and erythromycin and belong to many different phage type patterns. In Denmark, inducible resistance has occurred at a stable high frequency of approximately 90% of the erythromycin-resistant strains during the last 30 years. Erythromycin-resistant strains isolated today, however, have higher minimum inhibitory concentrations, and are rarely resistant to spectinomycin, in contrast to the strains isolated in the first half of the observation period.

Denmark↗
PubMed1991

Evolution of Staphylococcus aureus resistance to erythromycin in Denmark, 1959 to 1988: correlations between characteristics of erythromycin-resistant bacteraemia strains.

In an attempt to characterize erythromycin-resistant Staphylococcus aureus we present the intricate relationships between the following factors: phage type, period of isolation, antibiogram, minimum inhibitory concentration (MIC) to erythromycin, inducible or constitutive resistance, spectinomycin susceptibility, hospital- or community-acquired infection, and mortality rate. We studied 718 cases of bacteraemia with erythromycin-resistant S. aureus, occurring between 1959 and 1988. Central factors were phage type pattern, period of isolation, and antibiogram. Between 1959 and 1973 the majority of the erythromycin-resistant strains were multiresistant and belonged to the 83A complex and the related group III. They were mainly inducibly resistant, spectinomycin resistant, and had intermediate MICs (1-4 mg l-1) to erythromycin. The majority of these strains came from hospital-acquired infections and still exist today, although in decreased numbers. By contrast, erythromycin-resistant S. aureus isolated in recent years are usually co-resistant only to penicillin and more rarely also to tetracycline. These strains have inducible resistance, are spectinomycin susceptible, and have a high erythromycin MIC. They are isolated both from hospital- and community-acquired infections. Strains with constitutive resistance to macrolides occurred at a stable low level (13%) during the whole observation period and always had high MICs to erythromycin. The mortality rate among patients with S. aureus bacteraemia due to an erythromycin-resistant strain was only associated with the year of infection and decreased from 61% in the first 15-year period to 40% in the subsequent 15 years.

Bacteriophage Typing↗
PubMed1991

Clinical and parasitological studies on malaria in Liberian adults living under intense malaria transmission.

Occurrence of fevers and chills, headaches and body and joint pains, and body temperature and malaria parasitaemias were recorded monthly for a year for 121 Liberian adults. There was no apparent correlation between any of the symptoms and the presence or density of blood parasites; it was therefore not possible to define a case of clinical malaria in the study population, which was probably highly immune to infection. Only a few people with patent blood infections had elevated blood temperatures and these were below 37.5 degrees C. Malaria prevalence and levels of parasitaemia declined with age and indicated that immunity continues to develop well into adult age. The data did not support the view that adults experience symptoms at lower parasitaemias than children. Pregnant and non-pregnant women had similar levels of symptoms, but high levels of parasitaemia were found more frequently in the pregnant group.

Adult↗
PubMed1990

Changing remuneration systems: effects on activity in general practice.

OBJECTIVE: To investigate the effects on general practitioners' activities of a change in their remuneration from a capitation based system to a mixed fee per item and capitation based system. DESIGN: Follow up study with data collected from contact sheets completed by general practitioners in one period before (March 1987) a change in their remuneration system and two periods after (March 1988, November 1988), with a control group of general practitioners with a mixed fee per item and capitation based system throughout. SETTING: General practices in Copenhagen city (index group) and Copenhagen county (control group). SUBJECTS: 265 General practitioners in Copenhagen city, of whom 100 were selected randomly from the 130 who agreed to participate (10 exclusions) and 326 general practitioners in Copenhagen county. MAIN OUTCOME MEASURES: Number of consultations (face to face and by telephone) and renewals of prescriptions, diagnostic and curative services, and specialist and hospital referrals per 1000 enlisted patients in one week. RESULTS: Of the 75 general practitioners who completed all three sheets, four were excluded for incomplete data. Total contact rates per 1000 patients listed rose significantly compared with the rates before the change index in the city (100.0 before the change v 111.7 (95% confidence interval 106.4 to 117.4 after the change) and over the same time in the control group (100.0 v 106.0), but within a year these rates fell (to 104.2(99.1 to 109.6) and 104.0 respectively). There was an increase in consultations by telephone initially but not thereafter. Rates of examinations and treatments that attracted specific additional remuneration after the change rose significantly compared with those before (diagnostic services, 138.1 (118.7 to 160.5) and 159.5 (137.8 to 184.7) and curative services 194.6 (152.2 to 248.9) and 194.8(152.3 to 249.2) for second and third data collections respectively) and with the control group (diagnostic services 105.3, 107.6 and curative services 106.0, 115.0) whereas referral rates to secondary care fell (specialist referrals 90.1 (80.7 to 100.6) and 77.0 (68.6 to 86.4) and hospital referrals 87.4 (71.1 to 107.5) and 68.4 (54.7 to 85.4] in doctors in the city. CONCLUSIONS: Introducing a partial fee for service system seemed to stimulate the provision of services by general practitioners, resulting in reduced referral rates. The concept of a "target income" which doctors aim at, rather than maximising their income seemed to play a part in adjustment to changing the system of remuneration.

Capitation Fee↗
PubMed1990

The effect of a control program for enzootic bovine leukosis. Changes in herd prevalence in Denmark, 1969-1978.

As part of the Danish control program for enzootic bovine leukosis, three hematologic screenings of all cattle herds in Denmark were performed in the period 1969-1978. Herds with multiple cases of persistent lymphocytosis and/or leukotic tumors were classified as "leukosis herds." During nationwide blood testing, 369 leukosis herds were discovered, and an additional 77 herds were found due to follow-up of tumor cases or special testing in connection with movements of cattle in 1969-1978. In the present study, the prevalence of leukosis herds in the three screening rounds is related to geographic area and herd size. By means of a statistical log-linear model, the authors show that prevalence increased proportionally with herd size. The observed number of leukosis herds per 10,000 herds tested declined during the screening program from 105 to 38 in east Denmark and from 12 to 4 in west Denmark.

Animals↗
PubMedDate not supplied

Persistent and acute diarrhoea as the leading causes of child mortality in urban Guinea Bissau.

An investigation of child mortality in a semi-urban community, Bandim II, in the capital of Guinea Bissau was carried out from April 1987 to March 1990. 153 deaths were recorded among 1426 live-born children who were followed for 2753 child-years. The under-five mortality risk was 215 per 1000 children (95% confidence interval [CI] 176-264), infant mortality 94 per 1000 (95% CI 73-115), and perinatal mortality 52 per 1000 (95% CI 41-63). By prospective registration of morbidity, post-mortem interviews, and examination of available hospital records, a presumptive cause of death was established in 86% of the deaths. Persistent and acute diarrhoea were the most frequent causes of death, accounting for 43 and 31 deaths per 1000 children, respectively. Fever deaths (possibly malaria), neonatal deaths, acute respiratory infections, and measles were other frequent causes. The access to health services was relatively easy: 75% of the children who died had attended for treatment at a hospital or a health centre. It is important to find ways of preventing and managing persistent diarrhoea, the major cause of death, and to improve the control of acute diarrhoea by a targeted approach.

Acute Disease↗