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Biomedical subjects

E H Lehmann

Publications and source records attributed to E H Lehmann.

At least 19 recordsLinked to original sources
PubMed1996

[Conservative experimental groups in clinical comparative trials. Tables providing the minimum number of patients].

To calculate the minimum size of sample required for clinical trials it is first necessary to decide the expected difference between the groups, and then the acceptable risk of wrongly declaring a significant result (alpha) or wrongly declaring a non-significant result (beta). Once these three parameters are set, simple tables can show the necessary sample sizes. Such tables are presented for classical comparative studies, survival studies, and group sequential plans. Sequential plans often entail large savings in sample size compared with fixed group plans.

Biometry↗
PubMed1995

Dietary calcium, saturated fat, fiber and vitamin C as predictors of forearm cortical and trabecular bone mineral density in healthy children and adolescents.

Diet, weight-bearing physical activity (WPA) and daylight hours spent outdoors (DE) were related to bone mineral density in the distal (BMDd) and ultradistal (BMDud) forearm of 495 healthy children (8-11 years) and adolescents (11-17 years). BMD was assessed by single photon absorptiometry. Using multiple regression, BMDd was predicted by saturated fat and BMDud by fiber in children. In adolescents, BMDd was predicted by saturated fat and vitamin C, and BMDud by calcium and vitamin C. WPA and DE were not related to BMD. In conclusion, our results showed that current intake of calcium, saturated fat, fiber and vitamin C were positively associated with forearm BMD in children and adolescents. These associations depended on age and bone type. If our findings are verified, dietary recommendations, especially when aimed at young people, may have to be reconsidered.

Absorptiometry, Photon↗
PubMed1994

Assessment of coronary heart disease risk, II. A clinical multicentre study of general practitioners' risk assessment.

The objectives of the present study were: (i) to compare clinical assessment of coronary heart disease (CHD) risk with risk estimation faced with simulated, written case histories; (ii) to observe the risk assessment performed by general practitioners (GPs) in their clinical setting. Thirty-one GPs participating in a multicentre study were asked to invite 20 consecutive male patients aged 30-59 years to an opportunistic screening of CHD risk factors. They assessed the risk status of these patients and of 10 written case histories containing information about corresponding CHD risk factors. A composite 'infarction score' computed from epidemiologic data was used as a gold standard. Diagnostic performance in the clinical setting was compared with that in the simulated setting by Pearson's correlation. A weak, but statistically significant positive correlation was demonstrated when comparing correct estimation in the two settings. No correlation was found for over- and underestimation. Sensitivity was increased faced with clinical patients at the sacrifice of specificity compared to the simulated setting. The impact of a positive family history on clinical assessment parallels the epidemiological estimate. Due to lack of sensitivity, the other factors had a lower impact on risk estimation than an epidemiological estimate would presuppose. We advocate the application of a formal risk estimation to improve risk assessment accuracy. The synergistic effect of multiple risk factors should be emphasized in medical training to improve the clinical risk estimation.

Adult↗
PubMed1985

Oligodendroglioma: incidence and biological behavior in a defined population.

The cases of 208 patients with histologically confirmed oligodendrogliomas were studied. The incidence represents 4.2% of all primary brain tumors diagnosed in the Norwegian population over a 25-year period. All of these tumors were cerebral and the majority affected the frontal lobe. The patients' median age at diagnosis was 47 years, with a range from 3 to 76 years; 6% of the oligodendrogliomas occurred in children. The median duration of symptoms before diagnosis was 20.5 months (mean 43 months). Plain skull x-ray films showed calcified deposits in 28% of the tumors. At operation, most of the tumors were poorly defined, without cyst formation, hematoma necrosis, or calcification. The median duration of disease from onset of symptoms until death was 14 months in nine untreated cases. In surgically treated oligodendroglioma patients the median survival time from onset of symptoms was 74 months. The median postoperative survival time was 35 months (mean 52 months). Tumor calcification, as seen on plain skull x-ray films, was associated with a significantly longer survival period. The surgical findings of gross necrosis, gross hypervascularity, and soft tumor consistency were all related to a shorter total duration of disease. Grossly well demarcated lesions were associated with a significantly longer postoperative survival. The length of postoperative survival correlated with the preoperative clinical status. The cumulative proportion of patients surviving 5 years was 0.342. The patient's age and sex did not have a statistically significant influence on survival time. The extent of surgical excision only seemed to play a role when the neurosurgeon considered that he had removed the whole lesion: these patients had a median postoperative survival period 14 months longer than the other oligodendroglioma patients. The ABO blood group of the oligodendroglioma patient was of prognostic value. In particular, patients with blood group A had a distinctly poorer prognosis than patients with O or B blood. The survival data from this unselected series indicate that cerebral oligodendrogliomas have a less favorable prognosis than has generally been believed.

Adolescent↗
PubMed1985

Hearing acuity in professional divers.

Pure tone audiograms and relevant history were recorded in 164 professional divers aged 19 to 66 yr, mean 30.9. A close correlation exists between hearing impairment and increasing age, increasing diving experience, and acoustic trauma. A statistically significant elevation (P = 0.01) of the high-frequency hearing threshold is demonstrated in smokers as compared to those who had never smoked. The divers' hearing threshold was elevated in the high frequencies in all age groups as compared to ISO normality curves. It was, however, lower than that of a Norwegian standard population at a young age, but in their fourth decade of life, the divers' high frequency hearing was at the same level as that of the standard population. We conclude that professional diving may cause a more rapid deterioration of high-frequency hearing than seen in a standard population and that smoking may be an additional hazard to high-frequency hearing.

Adult↗
PubMed1984

Evaluation of dipsticks for the assessment of microhaematuria.

Three types of dipstick were evaluated for the detection of microhaematuria. One type showed no false positives with erythrocyte-free urine, and no false negatives with a urine erythrocyte concentration of 20 X 10(6)/l using 5-10 X 10(6)/l as limit. This pattern of readings was produced by all the observers, thus indicating that method variation was satisfactory. The two other types of dipstick were clearly less sensitive, and had less desirable characteristics.

Adult↗
PubMed1983

Heparin for infants and children with meningococcal septicemia. Results of a randomized therapeutic trial.

Heparin has been given intravenously, as part of a prospective study, to 11 of 26 infants and children with severe meningococcal septicemia. This therapy was started as early as possible following admission to hospital, and continued for two days. The age and sex distributions were roughly similar for the two treatment groups, but the prognostic signs on admission were somewhat less favourable for the group that did not receive heparin. Two boys who received heparin and two girls who did not, died. The clinical courses of the surviving patients in the two groups were also roughly similar, except that the tendency to cutaneous necroses was slightly more prominent in those who had not received heparin. We have thus no evidence that heparin has any great influence on the final outcome of meningococcal septicemia, even when given so early that shock had not developed.

Child↗
PubMed1978

The anamnestic effect in tuberculin skin testing: measurement and time relations. Experiments in BCG-vaccinated guinea pigs.

The repeat-test effect, an example of anamnestic effect in cellular immunity, was investigated in BCG-vaccinated guinea pigs, using 25 TU Mantoux tests to influence as well as assess skin reactivity to tuberculin. Two different methods of quantitating the effect were tried and found valuable. The effect could be regularly observed 12 weeks or more after BCG-vaccination, and with less regularly 6 to 9 weeks after BCG-vaccination. The effect was found whether the interval between the first (interim) test and the second (repeat) test was as short as 3 days or as long as 44 weeks.

Animals↗
PubMed1978

Tuberculosis infection and the repeat test. Effect in BCG-vaccinated guinea pigs.

Groups of BCG-vaccinated guinea pigs were infected with Mycobacterium tuberculosis and the course of tuberculin reactions before and after was studied. The infection led to reactions that were accelerated as if repeated tests had been given, but were larger than in such cases. Acceleration of reactions due to previous testing was present 1 week, but not 4 weeks after the start of the infection. Possibly, in cellular immunity in general, absence of the repeat test effect may be interpreted as a sign that specific antigen stimulation is taking place, and diagnostic tests could be constructed on this basis.

Animals↗
PubMed1977

Attempts to boost tuberculin skin reactions by serum or blood transfer in BCG-vaccinated guinea-pigs.

In persons with waning sensitivity to mycobacterial antigens, skin reactivity to tuberculin may be maintained or enhanced as a result of tuberculin testing. Similar phenomena have been observed in guinea-pigs. As tuberculin testing may lead to antibody formation, the "booster" effect might be due to circulating antibody. However, a series of nine pilot experiments including blood and serum transfer from boosted to unboosted BCG-vaccinated guinea-pigs gave no support to this hypothesis.

Animals↗
PubMed1976

The Tromsøo heart study. Methods and main results of the cross-sectional study.

The mortality from coronary heart disease (CHD) in Norway increased rapidly during 1951-70, the highest mortality rates as well as the most rapid increases being found in Northern Norway. Several surveys of CHD were then planned, one of them is reported here. All men, 20-49 years of age, living in the municipality of Tromsøo, Troms county, were called up for examination. In total, 6595 men, 74.4% of those invited, were examined. Cholesterol, triglyceride and Hb values, BP, body weight and height, the percentage of smokers, and cigarette consumption have been tabulated according to area, age, work schedule, health condition, physical activity and ethnic background. The results suggest that the relatively high mortality from CHD in Northern Norway is associated with high serum cholesterol concentrations as well as a relatively high prevalence of smoking. During the screening there were indications of changes in dietary habits in the municipality, presumably as a result of accompanying publicity.

Activity Cycles↗
PubMed1975

Course and outcome of pregnancy in women with pulmonary tuberculosis.

Medical registrations of births in Norway during 1967 and 1968 were utilized in a study of the course and outcome of pregnancy in 542 women with pulmonary tuberculosis. A comparison with 112,530 pregnancies in women reporting no disease was made. Tuberculous women were found to have an excess of pregnancy complications, miscarriage, and labour difficulties. Their live births, however, were comparable with respect to gestation period, birth weight, morbid conditions and mortality to those of women reporting no disease.

Birth Weight↗