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Biomedical subjects

E Ernst

Publications and source records attributed to E Ernst.

At least 847 records · Page 47Linked to original sources
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A follow-up study of environmental and biologic determinants of fertility among 430 Danish first-pregnancy planners: design and methods.

This paper presents design and methods of a follow-up study of fecundability (defined as the probability of conception during one menstrual cycle) in first-pregnancy planners. We recruited 430 couples by postal letter among 52,255 members of four trade unions. Couples without earlier reproductive experience were enrolled when they discontinued contraception and were followed in six complete menstrual cycles or until a pregnancy was recognized. Data included daily recordings of coitus and menstrual bleeding. Blood, semen, and urine specimens were collected to assess endocrine profile, semen quality, occult embryonal loss, and occupational exposures. Information was obtained about 1661 menstrual cycles (94% of expected). The proportion of couples obtaining a clinical pregnancy during 6 months of follow-up was 65%, and the average probability to obtain a pregnancy across all cycles was 16% (95% CI 14-18%). Among all conceptions the proportion of early embryonal loss was 17% (95% CI 12-22%). This study demonstrates the feasibility of a prospective study of fertility and that the established study base can provide useful information on environmental risk to subfertility.

Adult↗
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A follow-up study of male exposure to welding and time to pregnancy.

The aim of this study was to estimate whether male welding has an impact on couple fecundability (the probability of conceiving in a menstrual cycle). A sample of Danish couples without previous reproductive experience was recruited nationwide by postal letters to members of the union of metal workers and three other trade unions. Among 430 included couples, 201 males were metal workers and 130 were welders. The couples were followed for a maximum of six menstrual cycles from termination of birth control until a clinical pregnancy was detected. Compared with nonwelding metal workers the fecundability odds ratio (OR) of male exposure to welding was 0.86 (95% confidence interval [CI] 0.58-1.28). An interaction between male smoking and welding was found; within smokers the OR for welding was 0.40 (95% CI 0.17-0.95) and within nonsmokers it was 1.22 (95% CI 0.74-1.99). Previous welding exposure was negatively related to fecundability among smokers (OR 0.84 per year with mild steel welding, OR 0.76 per year with stainless steel welding). No significant results were found when comparing with an external group of nonmetal workers. Decreased fecundability among smoking welders attributable to both current and previous welding exposure is possible, but these findings were the results of subanalyses that were not part of the a priori hypothesis.

Adult↗
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Semen quality and sex hormones with reference to metal welding.

Welding may involve hazards to the male reproductive system, but previous studies of semen quality have produced inconsistent results. We studied the effects of welding on markers of semen quality in a Danish nationwide sample of 430 first-time pregnancy planners without earlier reproductive experience. Couples were recruited among members of the union of metal workers and three other trade unions and were followed from termination of birth control until pregnancy for a maximum of six menstrual cycles. The males provided semen samples in each cycle. Median sperm density for welders was 56 x 10(6)/mL (52.5 x 10(6)/mL and 50.0 x 10(6)/mL in two reference groups). No statistically significant differences attributable to welding were found in proportions of morphologically normal sperm, sperm motility assessed by computer-aided sperm analysis, or sex hormones (testosterone, follicle-stimulating hormone, and luteinizing hormone). These negative findings may not apply to populations with high-level exposure to welding fume or to welders exposed to other putative hazards, e.g., heat.

Adult↗
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Caffeine intake and fecundability: a follow-up study among 430 Danish couples planning their first pregnancy.

Fecundability has been defined as the ability to achieve a recognized pregnancy. Several studies on caffeine and fecundability have been conducted but have been inconclusive. This may be explained partly by lack of stratification by smoking. Furthermore, few researchers have tried to separate the effect of caffeine from different sources (coffee, tea, cola, and chocolate). Clearly, the relationship between caffeine and fecundability needs further research, given the high prevalence of caffeine intake among women of childbearing age. We examined the independent and combined effects of smoking and caffeine intake from different sources on the probability of conception. From 1992 to 1995, a total of 430 couples were recruited after a nationwide mailing of a personal letter to 52,255 trade union members who were 20 to 35 years old, lived with a partner, and had no previous reproductive experience. At enrollment and in six cycles of follow-up, both partners filled out a questionnaire on different factors including smoking habits and their intake of coffee, tea, chocolate, cola beverages, and chocolate bars. In all, 1596 cycles and 423 couples were included in the analyses. The cycle-specific association between caffeine intake and fecundability was analyzed in a logistic regression model with the outcome at each cycle (pregnant or not pregnant) in a Cox discrete model calculating the fecundability odds-ratio (FR). Compared to nonsmoking women with caffeine intake less than 300 mg/d, nonsmoking women who consumed 300 to 700 mg/d caffeine had a FR of 0.88 [95% confidence interval (CI) 0.60-1.31], whereas women with a higher caffeine intake had a FR = 0.63 (95% CI 0.25-1.60) after adjusting for female body mass index and alcohol intake, diseases of the female reproductive organs, semen quality, and duration of menstrual cycle. No dose-response relationship was found among smokers. Among males, the same decline in point estimates of the FR was present. Smoking women whose only source of caffeine was coffee (>300 mg/d) had a reduced fecundability odds-ratio (FR = 0.34; 95% CI 0.12-0.98). An interaction between caffeine and smoking is biologically plausible, and the lack of effect among smokers may be due to faster metabolism of caffeine. Our findings suggest that especially nonsmoking women who wish to achieve a pregnancy might benefit from a reduced caffeine intake.

Adult↗
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PC-assisted three-dimensional description of organs containing tubular structures, applied on the epididymis of the rat.

A concept for three-dimensional computer-assisted reconstruction of tubular organs, e.g. the epididymis, is described. Histologic serial sections without artificial landmarks from the epididymis of the Wistar rat were aligned. Virtual images through the aligned sections served as a control of the alignment process and can reveal new information about the structure of the organ under investigation. The method can be used for improving the anatomical description of the epididymis, i.e. how the ductus epididymidis is coiled along this organ. Other tubular tissues and organs can be investigated and analysed with this PC-assisted method, e.g. testis and kidney.

Algorithms↗
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Changes in blood volume during dialysis are dependent upon the rate and amount of ultrafiltrate.

Actual circulating blood volume during dialysis therapy can be monitored by continuous hemoglobinometry. Using this method in 15 stable, clinically nonoverhydrated dialysis patients, blood volume was recorded applying different modes of ultrafiltration: constant ultrafiltration (less than 500 ml/hr); high initial (greater than 1,500-2,000 ml/hr), subsequently decreasing ultrafiltration; and intermittently high (greater than 1,500 ml/hr) ultrafiltration. Mean amount of ultrafiltrate in all patients was 3,400 ml. Mean decrease in blood volume by 20% was generally tolerated without a decrease in blood pressure. Irrespective of the different modes of ultrafiltration, a decrease in blood volume was dependent only on the amount of ultrafiltered fluid. A constant, low ultrafiltration rate was not superior to a high ultrafiltration rate. In stable dialysis patients, decrease in blood volume is dependent only on the amount of ultrafiltrate. Up to a 20% decrease in blood volume, fluid can be removed from the patient even at a rate of 2,000 ml/hr.

Blood Flow Velocity↗
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Manual therapies for pain control: chiropractic and massage.

OBJECTIVES: To evaluate the effectiveness of chiropractic and massage therapy for the reduction of any type of pain. METHODS: Systematic reviews of chiropractic and massage as a means of pain control were located and evaluated. RESULTS: Six systematic reviews were found, 4 of chiropractic and 2 of massage therapy. Promising evidence emerged from some of these reviews but neither for chiropractic nor for massage was there fully convincing evidence for effectiveness in controlling musculoskeletal or other pain. DISCUSSION: The notion that chiropractic or massage are effective interventions for pain control has not been demonstrated convincingly through rigorous clinical trials.

Back Pain↗
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n-3 fatty acids and leukocyte chemotaxis. Effects in hyperlipidemia and dose-response studies in healthy men.

Dietary supplementation with n-3 polyunsaturated fatty acids (n-3 PUFAs) has been shown to inhibit neutrophil and monocyte chemotaxis in healthy subjects and, with respect to neutrophils, also in various patient groups. We studied the effect of dietary supplementation with n-3 PUFAs on monocyte and neutrophil chemotaxis in patients with hyperlipidemia. Chemotaxis was investigated with the under-agarose assay, using autologous serum and N-formyl-methionyl-leucyl-phenylalanine as chemoattractants. The patients were examined before and after 6 weeks of supplementation with 6 g n-3 PUFAs daily. Monocyte chemotaxis was reduced after n-3 PUFA supplementation in type IIa patients but was unaffected in patients with type IV hyperlipidemia. Furthermore, monocyte chemotaxis was increased in untreated type IIa patients compared with normocholesterolemic controls. We also studied the dose-response effects of n-3 PUFAs on monocyte and neutrophil chemotaxis in healthy men given 1.3, 4, and 9 g n-3 PUFAs daily for 6-week periods. Monocyte and neutrophil chemotaxis was reduced after n-3 PUFA supplements in a dose-dependent fashion, with the majority of the effect observed after the low dose. These results lend support to the notion of an antiatherosclerotic effect of n-3 PUFAs and may provide an explanation for the hitherto-unexplained effect of low doses of n-3 PUFAs in coronary heart disease.

Chemotaxis, Leukocyte↗
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Blood rheology in healthy cigarette smokers. Results from the MONICA project, Augsburg.

To investigate the relationship between cardiovascular risk factors and the fluidity of blood, a random sample of the population consisting of 4022 persons ages 25 to 64 years was investigated for plasma viscosity, hemoglobin, and total serum protein. A total of 567 healthy nonsmokers and 287 healthy smokers were identified and compared. Plasma viscosity was found to be elevated in male smokers; this was related to both the degree and the duration of cigarette abuse. Plasma viscosity proved to be age-dependent in smokers, but did not change with age in nonsmokers. Total serum protein decreased with age in nonsmokers, while it did not change in smokers. Hemoglobin increased only in female smokers. These findings suggest that blood fluidity is jeopardized in smokers. In men the hemorheological deficit is mostly due to a rise of plasma viscosity, which, in turn, may be caused by an elevation of plasma fibrinogen levels. In women it is predominantly due to an increase in hemoglobin. These alterations in hemorheological variables may be a marker for increased cardiovascular risk in smokers and could reduce blood flow and hinder microcirculatory function.

Adult↗
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Leukocyte rheology in recent stroke.

Eighteen patients with recent ischemic stroke were compared with an equal number of matched controls. Standardized suspensions of red cells as well as of red and white cells were filtered in a new filtration apparatus capable of discriminating between cell deformability and filter occlusion. Results show that red cell deformability, although slightly lower than in controls, is not significantly altered in stroke patients. Filter occlusion, however, was significantly higher in patients when red and white cell suspensions were filtered, but not when red cell suspensions were used, suggesting that white cell filterability is impaired after stroke, which could be due to decreased deformability and/or increased adhesiveness of leukocytes. Slowed white cell passage may also occur in the living microcirculation and may present an obstacle to nutritive flow in exchange vessels, possibly contributing to local ischemia and tissue necrosis after stroke.

Aged↗
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'If it helps my patient...' Perspectives on complementary medicine.

The argument 'if it helps my patient, I don't need science to prove that it works' is rife in complementary medicine. This article is an attempt to examine it from the perspective of the provider of complementary medicine, the clinical scientist and the politician. It is concluded that the dichotomy between experience and science is a regrettable misunderstanding. The revised argument should be 'if it helps my patient, I want research undertaken to find out whether more people could benefit from it'.

Attitude of Health Personnel↗
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[Subatomic biology: electronic biology, biosemiconductivity].

The author gives a critical and hystorical review of the existing in biology theories which on the molecular and electronic levels explain a number of mechanisms of vital phenomena such as excitation, muscle contraction etc. The author discusses in the hystorical aspect the problem of formation of electronic and biological semi-conductivity (as the author names it) called to explain the vital mechanisms. He shows is which way this theory can explain the process of excitation.

Biophysical Phenomena↗