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Biomedical subjects

B Nielsen

Publications and source records attributed to B Nielsen.

At least 325 records · Page 18Linked to original sources
PubMed1979

A gastroscopic and pharmacological study of the disintegration time and absorption of pivampicillin capsules and tablets.

1 An in vitro investigation showed that pivampicillin tablets disintegrated more rapidly than pivampicillin capsules. This result was demonstrated and confirmed by gastroscopy in a cross-over study in healthy volunteers. 2 There were no differences in serum levels of ampicillin obtained with the two preparations, but compared with non-gastroscoped volunteers, there was delay of 0.5--1.5 h in the appearance of peak serum ampicillin concentrations after gastroscopy. 3 Half of the volunteers receiving pivampicillin capsules developed hyperaemia, interstitial bleeding or erosions of the gastric mucous membrane. No such reactions were seen after pivampicillin tablets. 4 In one volunteer, a pivampicillin capsule was trapped in a not previously noticed hiatus hernia and local changes and pain occurred.

Adult↗
PubMed1979

The effect of water temperature on the hormonal response to prolonged swimming.

The relationship between thermoreception, hormonal secretion and muscular activity was studied. 6 men swam 60 min in 21, 27 and 33 degrees C water at a speed requiring 68% of VO2 max (determined in 27 degrees C water). Rectal temperature increased in 33 degrees C (1.3 +/- 0.2 degrees C, mean and S.E.) and 27 degrees C (0.7+/- 0.1 degrees C) expts. but decreased in 21 degrees C expts. (0.8 +/- 0.3 degrees C). Changes in esophageal and muscle temperatures parallelled changes in rectal temperature. Plasma noradrenaline was higher in 33 degrees C than in 27 degrees C expts. and growth hormone, cortisol and glucagon concentrations increased in 27 degrees C and 33 degrees C expts. only. Insulin concentrations were uniformly depressed during swimming at the different water temperatures. In 21 degrees C expts. noradrenaline and adrenaline concentrations were higher than in 27 degrees C expts. VO2, carbohydrate combustion and peak lactate were slightly lower in 33 degrees C expts. Plasma glucose decreased slightly and FFA and glycerol concentrations increased identically in all expts. Heart rate increased continuously during swimming in 27 degrees C and 33 degrees C expts., but not in 21 degrees C expts. In conclusion the rise in body temperatures normally observed during exercise enhances the exercise induced increases in the plasma concentrations of noradrenaline, cortisol, growth hormone and glucagon. Decreased body temperatures may elicit catecholamine secretion as a direct consequence of thermoreception. Shivering may account for previously observed decreases in insulin secretion during cold stress but not for increases in cortisol and growth hormone.

Adult↗
PubMed1978

Rapid fluid extraction with the Gambro Ultradiffuser.

Four patients were given fourteen treatments with the Gambro Ultradiffuser. One hour of ultrafiltration without dialysate and with negative pressure on the dialysate side was followed by four hours of dialysis with negligible transmembrane pressure (TMP). Mean fluid removal was 2678 ml per ultrafiltration period and the mean ultrafiltration rate was 37 ml/min. During the dialysis period, TMP was about +30 mmHg giving an ultrafiltration rate of 4 ml/min. Pulse rate was unchanged. Hematocrit increased 3%, plasma protein increased 21% and plasma albumin increased 25%. Plasma values of potassium, sodium, urea, creatinine and osmolality were unchanged. One patient experienced a reversible hearing loss during two ultrafiltration periods and two patients had severe, yet reversible, cardiac arrhythmias. One patient had hypertension during the ultrafiltration period. Rapid extraction of fluid up to 49 ml/min was possible. The mean mean arterial pressure was unchanged thought it exhibited great variation and three patients developed side effects.

Adult↗
PubMed1978

Bacteriological contamination of dialyzers. Clinical, bacteriological and scanning electron-microscopic evaluation of different dialysate mixing systems.

Membranes from Gambro Lundia Nova dialyzers were investigated for presence of bacteria after hemodialysis with centrally and peripherally mixed dialysate. Centrally mixed dialysate was found contaminated with Pseudomonas aeruginosa, and bacterial cultures as well as electron scanning micrographs showed the presence of these bacteria on the dialysate side as well as on the blood side of membranes from dialyzers perfused with this dialysate during hemodialysis. No bacteria were found on membranes used with peripherally mixed dialysate, in which very few bacteria were found. Despite this the frequency of febrile episodes in patients submitted to hemodialysis with the two different dialysate mixing systems showed no significant difference in our material.

Bacteria↗
PubMed1976

Metabolic reactions to changes in core and skin temperature in man.

The metabolic cold response, i.e. the increase in oxygen consumption above that for the given activity in a neutral environment, was measured in 7 subjects during cooling, resting or swimming in cold water (14, 16, 18, 20degrees C) and during rewarming in air (Ta 20, 30, 40degrees C), bicycling or resting. Esophageal temperatures varied between 38 and 34degrees C. Mean skin temperature was considered as equal to water temperature during cooling, and ranged between 25-35degrees C during rewarming in the different environments. Both central and peripheral cold stimulation induced metabolic cold responses. The skin temperature was the dominating factor in determining the response, especially in transient states. During rewarding a rising skin temperature suppressed the effects of even very low core temperatures.

Adult↗
PubMed1976

Temperature regulation during exercise in water and air.

Four healthy subjects were studied during exercise in water, using a swimming flume, and in air, on a stationary bicycle ergometer at mean skin temperatures of 30 and 33 degrees C, respectively. Measurements included rectal (Tre), esophageal (Tes), and mean skin (Ts) temperatures, metabolic energy liberation (M) and total heat production (H), maximal aerobic power output (Vo2 max), cardiac frequency and calculated peripheral tissue heat conductance (K). The results showed that for a given M and Ts, Tes and Tre were about 0.4 degree C lower and the K values were consistently higher in swimming than in bicycling. The intersubject variability in Tes and Tre was reduced by considering relative (expressed as %VO2max) rather than absolute work load, but the differences in the body temperatures between the two types of exercise remained. It was concluded that during exercise in water where the capacity for heat dissipation is increased, the body core temperature (Tc) is maintained at a lower level due to the higher forced convective and conductive heat transfer from the skin in water. This reduces the heat storage at the beginning of exercise compared with conditions in air. The lower Tc-Ts gradient for a given H in swimming, which results in higher K values implies a greater skin circulation than during cycling in air.

Adult↗
PubMed1976

Rehabilitation of Danish dialysis and transplant patients.

An evaluation of the extent of rehabilitation of 512 Danish dialysis and transplant patients, based on a questionnarie, has been carried out. All transplanted patients and dialysis patients and dialysis patients with only slightly limited working capacity before treatment experienced an improvement, whereas disabled dialysis patients did not experience major changes. Sixty per cent of the patients receive disablement pension and the allotment of pension early in the course of treatment is suspected to be one of the main reasons for the low degree of vocational rehabilitation.

Absenteeism↗