PubMed Health⌕ Search

Biomedical subjects

H E Refsum

Publications and source records attributed to H E Refsum.

At least 37 records · Page 2Linked to original sources
PubMed1989

Late sequelae of lung contusion.

Twenty-four patients with severe lung contusion and multiple rib fractures were studied at a mean 4.9 years (range 2-9 years) after injury. All patients had been in good health before the accident. After the accident 15 (63 per cent) patients had respiratory symptoms such as dyspnoea at rest or moderate exercise (4), pain (8), cough or increased expectoration (11) and frequent bronchopulmonary infections (5). Three patients had changed their job because of respiratory disturbance. The average vital capacity, forced expiratory volume in 1 s, maximal voluntary ventilation and CO transfer factor were reduced respectively to 87, 88, 82 and 83 per cent of predicted values (P less than 0.01), while total lung capacity, residual volume and helium mixing time showed no definite changes (P greater than 0.05). Arterial blood gases at rest and at maximum exercise showed slight changes only. Maximal working capacity and ECG, as well as the ventilatory cost of moderate exercise were normal, where as the CO2 recovery time after moderate exercise was slightly increased (P less than 0.05). Overall there was a tendency towards poorer function in patients treated with artificial ventilation. Chest radiographs were normal in 10 patients (42 per cent), and moderate changes were seen in 14 patients. Diaphragmatic movements were essentially normal in all patients. Severe injury to the chest causes frequent respiratory symptoms. However, objective tests were only moderately reduced when compared with normal values. There was no unequivocal association between the subjective symptoms and the pulmonary function.

Adult↗
PubMed1988

Postnatal anemia and thrombocytosis in suckling rabbits: influence of delayed weaning and iron supplies.

Two groups of suckling rabbits were studied from the 15th to the 40th day after birth, one group receiving mothers milk only, the other having the choice of iron-containing food pellets from the 20th day. In the milk-only group, the plasma iron concentration (P-Fe), blood hemoglobin concentration (B-Hb), red blood cell count (B-RBC), and mean corpuscular volume (MCV) declined continuously, whereas the hemoglobin mass of the blood (Hb-mass) remained unchanged, and the blood platelet count (B-PLTS), plasma platelet count (P-PLTS), and the estimated platelet release to the blood (PLT-release) showed a continuous rise. The milk-pellet group showed the same pattern until the 25th-30th day; thereafter, P-Fe, B-Hb, and Hb-mass rose markedly, whereas B-PLTS and PLT-release declined. At the time of weaning, both groups showed bimodal erythrocyte volume distribution curves. Thereafter, the milk-only group developed a pure microcytemia, whereas the milk-pellet group got normovolemic erythrocytes only. In conclusion, the erythropoiesis in suckling rabbits is characterized by a balanced recycling of an essentially constant amount of available iron, preventing rise of Hb-mass. The anemia thus reflects a failure of the Hb-mass to keep up with the growth-related rise in plasma volume. A close relationship exists between postnatal iron deficient microcytic anemia and thrombocytosis.

Anemia, Neonatal↗
PubMed1987

Haemodynamics during repeated exercise tests with special reference to the 'warm-up' phenomenon in patients with angina pectoris.

The haemodynamic effect of two successive supine exercise tests 20 min apart was examined in 12 patients with angina pectoris. All the patients had coronary artery disease verified by angiography and were accepted for coronary bypass surgery. They exercised 20-40 W and all of them had angina during the first exercise test. Half the patients did not experience angina during the second of the two exercise tests ('warm-up' responders). In these patients left ventricular filling pressure (LVFP) was reduced by 40% (P less than 0.01) in the second compared to the first exercise test. The non-responders showed no significant change in LVFP. The heart rate pressure product (RPP) and thus myocardial oxygen demand were unchanged in responders and non-responders. In another 10 patients with angina and coronary artery disease, also accepted for coronary bypass surgery, atropine (1.5-2.0 mg) was given intravenously. Ten minutes after administration of atropine, these patients followed exactly the same investigation programme including two successive supine exercise tests as in the group not given atropine. In the group given atropine, four 'warm-up' responders and six non-responders showed the same pattern of response in LVFP as in the group not given atropine. In the 'warm-up' responders a smaller increase in RPP was observed during the second exercise test compared to the first. The present study indicates that cholinergic mechanisms are probably not involved in the 'warm-up' phenomenon. Due to the difference in haemodynamic response, the 'warm-up' phenomenon has to be taken into account when evaluating results from haemodynamic studies of cardiovascular drugs.

Adult↗
PubMed1987

Haemoglobin O2 binding in newborn and adult rabbits.

The relationship between haemoglobin O2 saturation and 2,3-diphosphoglycerate concentration (2,3-DPG) in haemoglobin solutions equilibrated with 3.7% O2-5.7% CO2 were identical in newborn and adult rabbits over a wide range of 2,3-DPG (0.5-40.0 mumol g-1 Hb), and independent of the haemoglobin concentration (1-10 g dl-1). Also, the resistance of the haemoglobin to alkali denaturation and the spectrophotometric absorption spectra of carboxy and oxyhaemoglobin between 500 nm and 650 nm, as well as the isoelectric focusing pattern of the haemoglobin after early and late stabilization with CO, were the same in newborn and adult animals. Both demonstrated one dominant band, focusing at pH 7.17, and one less conspicuous at pH 7.40. The erythrocyte pH was higher in the newborn than in the adult animals. Isoelectric focusing of erythrocyte pyruvate kinase demonstrated two isoenzyme bands in the newborn animals, one dominant fraction at pH 5.85 and one minor fraction at pH 7.97, whereas only the pH 7.97 band was observed in the adult. It is concluded that the physical properties of the haemoglobin molecule itself are the same in newborn and adult rabbits, and that the postnatal decrease in haemoglobin O2 affinity is solely due to changes in the erythrocyte metabolism, leading to a marked rise in 2,3-DPG and a minor decline in erythrocyte pH. The rise in 2,3-DPG is caused by decrease of pyruvate kinase, probably due to proteolytic inactivation of the enzyme.

2,3-Diphosphoglycerate↗
PubMed1987

Regulation of erythropoiesis in suckling rabbits with and without postnatal anemia: partial suppression of production/release of erythropoiesis stimulating factor(s) by iron supplements.

The postnatal anemia in rabbits is accompanied by a marked rise in the plasma erythropoiesis stimulating factor(s) (ESF). The purpose of this study was to establish whether the increase in plasma ESF is only related to the anemia, or whether other mechanisms also are involved. Two matched groups of rabbits were studied from the 15th to the 36th day after birth. One group received iron parenterally and had no postnatal fall in hemoglobin concentration (Hb), the other developed the usual anemia. In both groups plasma ESF was undetectable on the 15th day, and also on the 22nd day, despite a marked fall in Hb in the untreated group and rise in the iron-treated group. Thereafter plasma ESF showed a slight, continuous rise in the nonanemic rabbits, in contrast to a marked, transient rise with maximum on the 29th day in the untreated group. On the 36th day there was no difference between the groups. In the iron-treated group the reticulocyte production rate remained unchanged, while the Hb mass rose continuously. In the untreated animals there was an initial decline in reticulocyte production rate, while Hb mass showed a slight increase. From the 29th day, however, reticulocyte production rate rose to the same level as in the iron-treated group and Hb mass rose markedly. In conclusion, the rise in plasma ESF during the postnatal anemia in rabbits is only in part related to the low Hb. Hypoxia-independent mechanisms, probably related to the growth and maturation per se also are involved. The lack of erythropoietic response to the rise in plasma ESF is due to lack of available iron.

Anemia↗
PubMed1986

Erythropoiesis-stimulating factor(s), erythropoiesis and erythrocyte 2,3-diphosphoglycerate in young rabbits with marked post-natal fall in haemoglobin.

The erythropoietic activity and erythrocyte 2,3-diphosphoglycerate (2,3-DPG) were studied during and after the nadir of the post-natal anaemia in normal, rapidly growing rabbits, from the 12th to the 35th day after birth. Whole blood haemoglobin (Hb) decreased from 9.3 g dl-1 on the 12th to 4.9 g dl-1 on the 25th day, while erythropoiesis-stimulating factor(s) (ESF) in plasma (determined by a cell culture assay) concomitantly rose from undetectable to high levels. In spite of marked rise in body weight, from 250 to 480 g, estimated haemoglobin mass (Hb mass) and reticulocyte mass production rate (Rt prod) remained essentially the same, about 1.8 g and 0.3 ml day-1. From the 25th to the 35th day, ESF decreased to a lower level, while Hb increased to 10.8 g dl-1 and Hb mass and Rt prod rose sharply, to 6.9 and 1.2 ml day-1. The 2,3-DPG rose markedly during the observation period, but showed a transient decline on the 29th day, simultaneously with the peak in reticulocyte counts (Rt) (24%) and release of young erythrocytes with low 2,3-DPG. The data indicate that the regions governing the erythropoietin production/release became increasingly sensitive to hypoxia during the observation period. The possibility also exists that the increase in ESF was due only in part to hypoxic stimulation. It could be related to the maturation of the animal in other ways, such as shift from extra-renal to renal erythropoietin production and the growth. The lack of response to increasing stimulation indicates that the erythropoiesis was restricted by the availability of iron and/or other factors necessary for erythrocyte and haemoglobin production.

2,3-Diphosphoglycerate↗
PubMed1985

Erythrocyte 2,3-diphosphoglycerate and erythropoietic activity in rabbits with severe bleeding anaemia superimposed in the early post-natal fall in haemoglobin.

Erythrocyte 2,3-diphosphoglycerate (2,3-DPG), whole blood haemoglobin (Hb), haematocrit (Hct), mean corpuscular haemoglobin concentration (MCHC) and reticulocyte percentage (Rt) were determined before and after bleeding in two groups of suckling chinchilla rabbits. One group was subjected to severe bleeding on the 12th, 15th, 18th and 21st day after birth and studied for 3 weeks, while the other was studied during the first 24 h after one severe bleeding on the 18th day. In the first group Hb and Hct fell to 2.7 g . dl-1 and 11.5%, respectively, on the 25th day. The fall was accompanied by a marked rise in Rt and decline in MCHC, reaching maximum and minimum on the 29th day, and a simultaneous, temporary decline in 2,3-DPG. In the other group the acute bleeding was accompanied by a marked fall in Hb and Hct, but no change in Rt and MCHC. 2,3-DPG was unchanged 8 h after the bleeding, but showed a rise during the following 16 h, definitely beyond the normal rise at this age. It is concluded that severe bleeding anaemia induces a rise in erythrocyte 2,3-DPG synthesis. However, the effect of the acute rise in 2,3-DPG is far from sufficient to maintain the O2 delivery capacity of the blood, and is completely offset by the influence of a subsequent change in the erythrocyte population towards younger cells with low 2,3-DPG.

2,3-Diphosphoglycerate↗
PubMed1985

Erythrocyte 2,3-diphosphoglycerate, PO2 50% and available O2 in rabbits with bleeding anaemia superimposed on the early post-natal fall in haemoglobin.

Erythrocyte 2,3-diphosphoglycerate (2,3-DPG), PO2 50%, whole blood haemoglobin (Hb), haematocrit (Hct) and available O2 were determined in two matched groups of suckling rabbits from the 17th to the 34th day after birth. One group was subjected to repeated bleeding, amounting to 1.0-1.5% of the body weight, on day 17, 19, 22 and 25, while the other served as control. The bleeding group had markedly lower Hb and Hct than the control group, which showed the ordinary post-natal fall in Hb. There were, however, no differences between 2,3-DPG and PO2 50% in the two groups. The changes were essentially the same as observed previously in animals in which the post-natal anaemia was avoided by iron-treatment. Thus, these and previously reported data show that the post-natal rise in 2,3-DPG and PO2 50% within wide limits is uninfluenced by marked variations in Hb, even severe bleeding anaemia, and support the assumption that the post-natal rise in 2,3-DPG and PO2 50% is dominated by processes related to the growth and maturation of the animals.

2,3-Diphosphoglycerate↗
PubMed1984

Erythrocyte 2,3-diphosphoglycerate, PO250%, and available oxygen in young rabbits with and without postnatal fall in hemoglobin.

We determined erythrocyte 2,3-diphosphoglycerate (2,3-DPG), PO250%, whole blood hemoglobin concentration, and available O2 from the 12th to the 30th d after birth in two matched groups of young rabbits. One group received iron parenterally on the 12th, 15th, and 18th d and the other received no iron supplement. In the untreated group there was a marked fall in hemoglobin concentration from the 12th to the 22nd d and thereafter a marked increase to the initial level on the 30th d whereas the iron-treated animals showed a marked rise in hemoglobin concentration from the 12th to the 22nd d, and a subsequent, slight decline from the 22nd to the 30th d. The average values of PO250% and 2,3-DPG, and the changes in PO250% and 2,3-DPG were virtually identical for both groups. During the first period (12-22 d) there was a marked rise in both 2,3-DPG and PO250% whereas in the second period (22-30 d) there was a somewhat smaller rise in 2,3-DPG and only a slight tendency toward a further rise in PO250%. In the untreated animals "available O2," reflecting the O2 delivery capacity of the blood, remained unchanged during the period of fall in hemoglobin concentration and showed a rise during the second period. In the iron-treated animals "available O2" rose markedly during the first period, with iron-treatment, and remained unchanged during the second period. We conclude that the marked postnatal rise in 2,3-DPG and PO250% in the rabbit seems to be independent of the changes in the hemoglobin concentration.

2,3-Diphosphoglycerate↗
PubMed1983

A critical evaluation of energy expenditure estimates based on individual O2 consumption/heart rate curves and average daily heart rate.

To test the applicability of indirect estimation of daily energy expenditure from average daily heart rate (HR) and individual O2-intake/heart rate (VO2/HR) regression lines in subjects with metabolic disorders, VO2/HR regression lines were determined on 2 consecutive days in 17 subjects (five healthy, five with obesity, five with untreated thyrotoxicosis, two with anorexia nervosa). Daily energy expenditure was calculated by means of the average 24 h HR. Generally, there was a high correlation coefficient for the relationship between VO2 and HR, but the slopes and intercepts varied considerably from day to day, leading to poor agreement between duplicate estimates of energy expenditures, and not infrequently to physiologically meaningless values. Further studies, comprising determination of the VO2/HR regression lines in three different body positions on 7 different days in one experienced test subject showed great variability of the VO2/HR regression lines, both in the same position and in different positions. The applied procedure seems unsuitable for metabolic studies in individual patients who engage in ordinary daily activities with low energy expenditure.

Adolescent↗
PubMed1983

Paranoiac psychoses: a follow-up.

74 patients with paranoiac psychoses were followed up. Paranoiac psychoses are characterized by affect-laden delusions, resemble the paranoias of Kraepelin, but have a better prognosis. 18 cases appeared to show a chronic course of illness, but only 1 case needed prolonged hospitalization in a mental hospital. Paranoiac psychoses are considered benign insofar as they have a nonschizophrenic long-term outcome. They resemble schizophrenic psychoses because the familial loading of psychoses is predominantly schizophrenic. To a great extent, the clinical picture revealed typical schizophrenic symptoms at the onset of the illness, so that at discharge from hospital there were often doubts as to whether psychoses should be classified as schizophrenias.

Aged↗
PubMed1982

Erythrocyte 2,3-DPG, PO2 50% and available O2 during the early post-natal fall in hemoglobin in rabbits.

Erythrocyte 2,3-DPG, PO2 50%, whole blood hemoglobin and available O2, and fixed acid Bohr effect were studied during the first 10 days after birth in rapidly growing suckling rabbits. The post-natal fall in hemoglobin concentration was accompanied by a marked rise in erythrocyte 2,3-DPG and a gradual increase in PO2 50%. The rise in PO2 50% was sufficient to keep the available O2 of the blood unchanged throughout the observation period. The observations show that a 2,3-DPG mediated rise in PO2 50% very effectively contributes to maintenance of adequate tissue oxygenation during the post-natal fall in hemoglobin. The rise in 2,3-DPG and and PO2 50% may be due to the ordinary hypoxia-induced shift to the right of the hemoglobin O2 dissociation curve, as observed under other circumstances when blood hemoglobin is rapidly reduced, but the very marked rise in 2,3-DPG and the very low delta PO2 50%/delta 2,3-DPG ratio suggest that the rise may as well be due to hypoxia independent, pre-programmed processes. The fixed acid Bohr effect was essentially the same in newborn and adult rabbits, and was uninfluenced by large variations in 2,3-DPG.

2,3-Diphosphoglycerate↗
PubMed1981

Changes in 2,3-Diphosphoglycerate (2,3-DPG) after exercise.

Previous studies of the influence of physical exercise on erythrocyte 2,3-DPG have shown conflicting results, including that exercise induces increase, decrease or no changes in 2,3-DPG. Assuming that the interplay between the factors governing 2,3-DPG metabolism may change considerably during the early phase of recovery after exercise, the level of erythrocyte 2,3-DPG was examined over a prolonged period of time after heavy exercise in five healthy men, on 3 separate days, the duration of exercise being 6 min, 6 min + 6 min with 1 h of rest between, and 60 min, respectively. The short exercise periods were accompanied by a substantial lactate acidosis, whereas the 60 min work was essentially aerobic. With the 6 min work, the erythrocyte 2,3-DPG was unchanged or slightly reduced immediately after and 15 min after the end of exercise, then rose to a new level, 8% above the initial level, 30 min after the exercise (P less than 0.001). With the 6 + 6 min work, the pattern of change followed both bouts of exercise, resulting in a two-step increase of 2,3-DPG, to a new level 12% above its initial value (P less than 0.001). With the 60 min work, 2,3-DPG was increased after a new level, 10% above initial value, 45 min after the exercise (P less than 0.001). With all three types of exercise 2,3-DPG remained unchanged during the following 4 h. Thus, heavy exercise is followed by a definite, slowly developing increase in erythrocyte 2,3-DPG, reaching a new level 30-45 min after exercise.

2,3-Diphosphoglycerate↗
PubMed1980

Reactive depression: a follow-up.

93 cases of reactive depression have been followed up in order to investigate the long-term course of illness. By independent classification of reactive and endogenous depressions the authors agreed on diagnosis for 94%. Ten subgroups of reactive depressions are illustrated by case histories. It is of practical importance to establish the clinical diagnosis of reactive depression because these states are different from endogenous depressions with regard to pathogenesis, prognosis and treatment.

Adjustment Disorders↗
PubMed1980

Excretion of casts and uromucoid in urine after prolonged heavy exercise.

Excretion of uromucoid, albumin and casts in urine were determined in twenty well-trained men, ten aged 20-30 years, and ten aged 50-60 years, before, during and after a 70 km cross country ski race. During the race there was only a slight increase in uromucoid excretion, but a marked increase in the excretion of casts and albumin. The older subjects had a tendency to lower urine output during the race compared to the younger group. Reduction of urine output below ca. 25 ml/h was accompanied by a conspicuous increase in urine cast and albumin concentrations, with only a slight increase in uromucoid concentration, and even a reduction in uromucoid excretion. No significant relationship was found between cast excretion and uromucoid concentration. Thus the gross cylindruria observed during longstanding exercise must be ascribed to other urinary factors facilitating the formation of casts.

Adult↗
PubMed1980

High density lipoprotein cholesterol, total cholesterol and triglycerides in serum after a single exposure to prolonged heavy exercise.

Serum high density lipoprotein (HDL) cholesterol, total serum cholesterol and triglycerides were determined in twenty men before, immediately after, and 1, 2 and 4 days after a 70 km cross-country ski race. HDL cholesterol increased by 12% of the pre-race level immediately after the race, rose further to 17% above the initial level on the following day, and was still elevated 4 days after the race. LDL + VLDL cholesterol, however, showed a tendency to decrease immediately after the race and was reduced by 17% and 11% of the pre-race level on the following 2 days. Triglycerides were reduced by 30% of the initial level immediately after the race, were still low on the following day, but were restored to normal 2 days after the race. It is concluded that a single exposure to prolonged heavy exercise induces changes in the HDL metabolism, showing that the physical exercise per se plays an important role for the increased HDL level seen in well-trained athletes.

Adult↗
PubMed1979

Haemolysis in athletes due to hereditary spherocytosis.

Three athletes, one cross-country skier and two middle distance runners, experiencing poor response to intensified training and decline in performance during prolonged periods of frequent competitions, associated with a tendency to develop anaemia, were found to have spherocytosis, and increased osmotic fragility of the red blood cells. All had family members with the same blood abnormality, but without symptoms. The observations suggest that the frequency of hereditary spherocytosis is higher than indicated by overtly affected cases and that mild cases are easily overlooked. Hereditary spherocytosis should be looked for in athletes with a tendency to decline in blood haemoglobin concentration during periods of intensive training and competition.

Adult↗