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Biomedical subjects

E S Hansen

Publications and source records attributed to E S Hansen.

At least 127 records · Page 7Linked to original sources
PubMed1987

Cerebral blood flow, cerebral metabolic rate of oxygen and relative CO2-reactivity during craniotomy for supratentorial cerebral tumours in halothane anaesthesia. A dose-response study.

Fourteen patients were studied during craniotomy for small supratentorial cerebral tumours. Cerebral blood flow (CBF) and cerebral metabolic rate of oxygen (CMRO2) were measured twice by a modification of the Kety-Schmidt technique using 133Xe intravenously. Anaesthesia was induced with thiopental 4-6 mg kg-1, fentanyl and pancuronium, and maintained with an inspiratory halothane concentration of 0.45% in nitrous oxide 67% at a moderate hypocapnic level. In one group of patients (n = 7) the inspiratory halothane concentration was maintained at 0.45% throughout anaesthesia. About 1 h after induction of anaesthesia CBF and CMRO2 averaged 35 +/- 2 ml 100 g-1 min-1 and 2.7 +/- 0.3 ml O2 100 g-1 min-1 (mean +/- s.c. mean), respectively. During repeat studies 1 h later CBF and CMRO2 did not change. In another group of patients (n = 7) an increase in halothane concentration from 0.45% to 0.90% was associated with a significant decrease in CMRO2 from 2.3 +/- 0.1 to 2.0 +/- 0.1 ml O2 100 g-1 min-1. The CO2-reactivity measured after the second flow measurement was preserved. It is concluded that halothane in this study induces a dose-dependent decrease in cerebral metabolism, an increase in CBF while CO2-reactivity is maintained.

Adolescent↗
PubMed1987

Tissue vitality in septic gonitis. 99mTc-DPD scintimetry in puppies.

After a single intraarticular injection of 10(9) Staphylococcus aureus in 12 puppies, septic arthritis developed in all the experimental knees after 48 hours. A considerable variability in scintigraphic appearance was observed. The juxtaarticular growth plates showed either unchanged or slightly decreased uptake except in 1 dog exhibiting a definite increase in tracer uptake. The epiphyseal uptake showed no consistent pattern. The intraarticular pressure of the arthritic joints increased significantly, but was not related to the tracer uptake pattern. We conclude that delayed joint scintigraphy as a single investigation in early septic arthritis does not provide diagnostic information and may be misleading.

Animals↗
PubMed1986

Parallel measurements of heat production and thermogenin content in brown fat cells during cold acclimation of rats.

The maximum thermogenic capacity of brown fat cells from control and cold acclimated rats was measured using a continuous-flow microcalorimetric system. The content of the 32.000 D, brown fat specific protein, thermogenin, was measured in the cells used for heat production measurements by competitive ELISA. The ratio between the maximal thermogenic capacity and the amount of thermogenin for control and cold acclimated rats was compared. It was found that the ratio between the two parameters decreased during cold acclimation due to a decrease in maximal thermogenic capacity and an increase in the amount of thermogenin, indicating regulation of heat production either at thermogenin or receptor level.

Acclimatization↗
PubMed1986

99mTc-DPD uptake in juvenile arthritis. Scintimetry and autoradiography of the knee in dogs.

Unilateral arthritis of the knee was induced in mongrel puppies by intraarticular injections of 1% Carragheenan. Bone metabolism was studied by a scintimetric technique on static 99mTc-diphosphonate bone scans every 2nd week during the induction of arthritis for 3 months and monthly in a postarthritic phase of another 3 months. Changes in uptake of radionuclide were present after 2 weeks. The induction phase was characterized by a decreased uptake in the calcification layer of the juxta-articular growth plates and a moderately increased epiphyseal uptake. The postarthritic phase was characterized by normalization of growth plate uptake and a marked increase in epiphyseal uptake. Using contact autoradiography, the epiphyseal uptake was seen mainly in a narrow subchondral and subsynovial bone layer, around bone cysts and osteophytes, whereas central epiphyseal bone was osteopenic with decreased uptake of tracer. The study suggests that the early scintigraphic appearance of juvenile non-suppurative arthritis may be an overall decrease in uptake of 99mTc-diphosphonate due to a depression of growth plate metabolism.

Animals↗
PubMed1985

Limitations in the use of the enzyme-linked immunosorbent assay (ELISA) for identification and quantification of thermogenin.

The use of immunological assays, ELISA and RIA, for the identification and quantification of thermogenin (the brown adipose tissue-specific, GDP-binding, 32 kDa uncoupling protein) raises doubts regarding the exclusive occurrence of thermogenin in brown adipose tissue. Weak reactions between mitochondria from rat liver, rat skeletal and heart muscle and hamster white adipose and thermogenin antibodies have been observed (Cannon et al., 1982; Lean et al., 1983; Hansen et al., 1984). In order to study whether these reactions were due to thermogenin in tissues other than brown adipose tissue (BAT) or due to non-specific binding of thermogenin antibodies, a protein from rat liver mitochondria and a protein from tubifex mitochondria were isolated by the same procedure as thermogenin. The 2 proteins had almost the same molecular weight as thermogenin and reacted with thermogenin antibodies in ELISA and dot-blotting, but did not bind GDP and had an amino acid composition different from that of thermogenin. It is concluded that the weak reactions seen between thermogenin antibodies and mitochondria from different tissues other than BAT are due to non-specific binding, and that antibody cross-reactivity alone is unsuitable for the identification of thermogenin.

Adipose Tissue↗
PubMed1984

Enzyme-linked immunosorbent assay (ELISA) studies of the interaction between mammalian and avian anti-thermogenin antibodies and brown-adipose-tissue mitochondria from different species.

Three different antibody preparations, rabbit anti-hamster and rabbit anti-rat thermogenin sera and chicken anti-rat thermogenin IgG, were tested for cross-reactivity towards isolated thermogenin and BAT mitochondria from different mammalian species using an ELISA-technique. It was found that the antibody preparations readily cross-reacted with different species, but that the affinity of the antibody preparations was greater towards the homologous species than the other species. The reactivity of an antibody preparation towards mitochondria from different tissues from the homologous species was also tested, and the exclusive occurrence of thermogenin in BAT could be confirmed.

Acclimatization↗
PubMed1984

Prediction of weights in humans after overfeeding using the Payne-Dugdale model.

Payne & Dugdale (1977) have proposed a model for predicting body weight in humans when the individual lean : fat tissue deposition ratio, energy intake +/- s.d. and energy expenditure +/- s.d. are known. The model was tested in 8 individuals, whose actual weights, energy intakes and expenditures (with their standard deviations) for a normal period, a semi-starvation period and an overfeeding period of 2 weeks were known or estimated. With the model, the lean : fat tissue deposition ratio for each person was calculated from the data of the semi-starvation period. From this ratio the model was able to predict a body weight equal to the one observed for the normal period. For the overeating period, the model predicted body weights which were considerably higher than the ones observed. Some explanations for this phenomenon are discussed.

Adipose Tissue↗
PubMed1983

Mortality from cancer and ischemic heart disease in Danish chimney sweeps: a five-year follow-up.

A mortality study of 713 male chimney sweeps in Denmark was performed. The observed number of deaths in 1970-1975 was compared with the expected number, calculated from cohort, period, and cause-specific death rates for employed Danish males. A total of 38 deaths was observed compared with the 18.3 deaths expected (p less than 0.01). Cancer accounted for 12 deaths versus 5.3 expected (p less than 0.05), ischemic heart disease for 12 deaths versus 5.4 expected (p less than 0.05), and residual causes for 14 deaths versus 7.6 expected (p less than 0.05). The excess mortality was exclusively due to cancer and ischemic heart disease among chimney sweeps in the older age group (45-74 years), whereas a high mortality due to other causes was observed among the younger sweeps (15-44 years). It is concluded that heavy inhalation exposure to products from the combustion of fossil fuel leads to an increased individual risk of cancer and ischemic heart disease and substantially reduces the time until occurrence of these diseases.

Adolescent↗
PubMed1982

Continuous flow microcalorimetric measurement of heat production in white adipose tissue from obese (ob/ob) mice and their lean littermates.

Heat production, free fatty acid and glycerol release from white adipose tissue fat pads from obese (ob/ob) mice and their lean littermates are determined. Heat production was significantly lower in obese mice compared to lean mice when expressed on wet weight basis but not when expressed on DNA basis. Noradrenaline significantly increased the heat production in fat pads from both groups of animals. However, the increase in heat production due to noradrenaline addition in fat pads from lean mice was significantly higher than in fat pads from obese mice. The release of free fatty acids and glycerol before incubation with noradrenaline was similar from fat pads from both groups of animals. Addition of noradrenaline to the fat pads increased the release of free fatty acids and glycerol in both groups of animals, but the increase was significantly larger from fat pads from lean mice. In the absence of noradrenaline the free fatty acid/glycerol ratio (mol/mol) in the effluent was 7.9:1 and 4.8:1 for lean mice and obese mice, respectively. In the presence of noradrenaline the ratio decreased to 3:1 for both groups of animals.

Adipose Tissue↗
PubMed1982

Cancer and non-cancer mortality of chimney sweeps in Copenhagen.

This is a cohort study of the mortality among chimney sweeps in Copenhagen, Denmark, during 1958-77. Nearly all the chimney sweeps started in the trade around the age of 15, and so this age gives the time of first exposure to the environmental conditions of the trade. The analysis applies a continuous time model with stratification by cause of death (cancer, non-cancer), time and age, where cumulative mortality rates are derived from current mortality tables. For each stratum of interest the observed/expected mortality ratio (O/E ratio) is calculated and a test performed, based on the normal distribution. The main result is a significantly higher cancer mortality for the 40-69 year age class compared with the population at large (O/E ratio = 3.9).

Adolescent↗
PubMed1982

Effects of excessive caloric intake and caloric restriction on body weight and energy expenditure at rest and light exercise.

The individual response to overeating and semistarvation on energy expenditure at rest and light work before and after a test meal was investigated. This response was related to the change in dry body weight, measured as weight (W) minus total body water (TBW). Experiments were performed on 9 non-obese subjects: (a) with a normal habitual energy intake; (b) (overfeeding) with an extra energy intake of 12 MJ per day for two weeks; and (c) (semistarving) with an energy intake of only 2.1 MJ per day for 2 weeks. Measurements of VO2, VCO2, W and TBW were obtained at the end of each of the three periods. It was found that the perturbation in energy intake from normal to 20-25 MJ per day increased the energy expenditure. The magnitude of this increase was highly individual and inversely related to the change in dry body weight. Energy expenditure, measured under the four standardized conditions, after 2 weeks of starvation was lower than that obtained after the preceding overeating period. This decrease was also roughly inversely related to the change in dry body weight. The results support the idea that part of the regulation of body energy content takes place by way of a change in the efficiency of energy utilization and that the response to a perturbed energy intake varies considerably between subjects.

Adult↗
PubMed1981

The prevalence of focal tubulo-interstitial lesions in various renal diseases.

The focal tubulo-interstitial lesions (FTIL) described in the present paper appear as short segments of tubules showing epithelial degeneration, necrosis and desquamation. The foci are surrounded by mononuclear cells, among which lymphocytes are most numerous. They infiltrate through the damaged tubular basement membranes and may thus be located between epithelial cells and in the tubular lumen. Older lesions show focal tubular atrophy with thickened basement membranes together with focal interstitial fibrosis and lymphocytic infiltrates. The overall prevalence of this type of lesion in a consecutive renal biopsy series was 36%. It was not detected in 24 biopsies from patients without renal disease. The frequency of FTIL was high in acute renal failure due to hemolysis, shock etc. or to the action of drugs, as well as in some types of glomerulonephritis (membranous, membrano-proliferative, SLE). Tubular immunoglobulins were not demonstrated in 38 biopsies with FTIL. The pathogenesis and possible consequence of the lesions are still unclear, but it is suggested that they may in some situations contribute to the nephron atrophy in chronic renal disease.

Atrophy↗
PubMed1979

Ulcer risk in a duodeno-gastric antireflux operation in dogs.

Duodenogastric reflux is a possible pathogenetic mechanism in some type I gastric ulcers. An antireflux operation is therefore a logical procedure but involves the risk of marginal ulceration. To examine this risk, the following study was performed: 18 dogs were divided into 3 groups of 6. One group had an antireflux operation performed (AR), one had AR plus parietal cell vagotomy (AR + PCV), and the third was a control group that was given daily injections of 40 mg repository histamine. All control dogs developed ulcers after 7-84 days, mean 37 days, of histamine. Three dogs in the AR group developed ulcers spontaneously 55-92 days postoperatively, whereas none of the AR + PCV group developed ulcers spontaneously 72-108 days postoperatively. After histamine injection two of the remaining three AR dogs developed ulcers after 3-4 days of stimulation, and three of the six AR + PCV dogs developed ulcers after 4-5 days of stimulation. It is concluded that the AR operation is heavily ulcer-prone and that PCV does not protect sufficiently against ulceration.

Animals↗