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Biomedical subjects

B Lund

Publications and source records attributed to B Lund.

At least 19 recordsLinked to original sources

Myopathy in bone loss of ageing: improvement by treatment with 1 alpha-hydroxycholecalciferol and calcium.

1. Eleven patients with the bone loss of ageing were treated with the vitamin D analogue 1 alpha-hydroxycholecalciferol and calcium for 3--6 months. 2. Muscle biopsies were taken from the vastus lateralis before and after the treatment and the activity of several enzymes was measured. Succinate dehydrogenase and total phosphorylase activities, which are a measure of the oxidative capacity, were low and increased significantly with the treatment. The lactate dehydrogenase activity, which can be taken as a measure of the anaerobic metabolism, was normal and did not change with treatment. The phosphagen stores, ATP and creatine phosphate were low and increased to normal with treatment. 3. Histochemical classification of the fibre composition revealed that the treatment induced an increase in the relative number of fast-twitch a (FTa or type II A) fibres accompanied by a reduction of the fast-twitch b (FTb or type II B) fibres. The cross-sectional area of the FTa fibres also increased with the treatment. 4. The present findings indicate that treatment with the active vitamin D analogue, 1 alpha-hydroxycholecalciferol, and calcium improves the myopathy associated with the bone loss of ageing.

Aged

Impairment of vitamin D and bone metabolism in patients with bypass operation for obesity.

Thirty-four patients were studied 2--6 years after jejunoileal bypass for morbid obesity. The serum concentration of 25-hydroxyvitamin D (25-OHD) were reduced and related to the frequency fo stools and to the weight reduction. Fifteen patients were not able to normalize serum 25-OHD following a long-term regular vitamin D intake. The serum immunoreactive parathyroid hormone concentration (iPTH) and the alkaline phosphatase levels were elevated in this group, indicating a secondary hyperparathyroidism. The mean bone mineral content of the forearm was reduced 3--6 years after the operation, most severely in those with elevated serum iPTH. The desired weight reduction by jejunoileal shunt was obtained at the expense of a severely disturbed vitamin D metabolism. We suggest, that all patients with an intestinal bypass for obesity should receive regular vitamin D supplement, and serum 25-OHD should be measured in order to monitor the effect of therapy.

Adult

Fractional intestinal calcium absorption in epileptics on anticonvulsant therapy. Short-term effect of 1,25-dihydroxycholecalciferol and 25-hydroxycholecalciferol.

Fractional intestinal 47Ca calcium absorption (alpha) in 12 epileptic outpatients receiving chronic high-dose anticonvulsant therapy was reduced (p less than 0.05) compared to 12 matched normal controls. Six of the epileptics were treated orally with 0.5 microgram of 1,25-dihydroxycholecalciferol (1,25-DHCC) per day and six with 10 microgram of 25-hydroxycholecalciferol (25-HCC) per day for 10 days. The alpha was determined before and after treatment and compared with the effect of 0.5 microgram of 1,25-DHCC per day given for 10 days to 6 controls. An increase of the same order in alpha was found in all groups (p less than 0.05). No changes were observed in the serum levels of calcium, phosphorus, alkaline phosphatase or iPTH during treatment. Urinary calcium excretion was low in the epileptic patients and rose during treatment. The investigation demonstrates that the sensitivity of the intestine to 1,25-DHCC is normal in epileptic patients on anticonvulsant therapy and that 1,25-DHCC and 25-HCC in the given doses had an equal effect on the reduced intestinal calcium absorption.

Administration, Oral

Reduced vibratory perception and corneal sensitivity and metabolic disturbances following intestinal bypass surgery.

Decreased corneal sensitivity and vibratory perception suggesting a diagnosis of polyneuropathy were demonstrated in some of 26 patients who had undergone intestinal bypass surgery. Psychological tests revealed signs of disturbance of the autonomic nervous system. A deficiency of 25-hydroxyvitamin D was demonstrated, clearly related to the frequency of stools and to the weight loss. This deficiency might play a role in the pathogenesis of the polyneuropathy.

Adolescent

Acromegaly and vitamin D metabolism: effect of bromocriptine treatment.

Fifteen acromegalic subjects were found to have elevated plasma levels of both 1,25(OH)2-vitamin D, 65 +/- 23 (SD) pg/ml [normal 33 + 15 pg/ml (SD)] and 24,25(OH)2-vitamin D, 6.8 +/- 1.6 (SD) ng/ml [normal 3.4 + 1.2 ng/ml (SD)]. Treatment with bromocriptine for 6 months reduced the plasma 1,25(OH)2-vitamin D3 level to 40 +/- 13 (SD) pg/ml, p less than 0.01 and the 24,25(OH)2-vitamin D level to 5.4 +/- 1.7 (SD) ng/ml, p less than 0.05.

Acromegaly

Measurement of circulating 1,25-dihydroxyvitamin D in man. Changes in serum concentrations during treatment with 1 alpha-hydroxycholecalciferol.

A sensitive assay is described for measurement of circulating 1,25-dihydroxyvitamin D (1,25-(OH)2D) using rachitic chick intestinal cytosol binding protein. The metabolite was extracted from serum by diethyl ether and chromotographed on a Sephadex LH-20 column followed by high-pressure liquid chromatography. The concentration of 1,25-(OH)2D was then measured by a competitive protein-binding assay. The binding capacity of the protein was unchanged for 4 months. The inter- and intra-assay variations were both 11%. The standard curve was useful at serum concentrations ranging from 14 to 395 pmol/l (6 to 165 pg/ml). The normal mean concentration was 79.6 +/- 36.8 pmol/l (33.1 +/- 15.3 pg/ml). The serum 1,25-(OH)2D was studied in elderly subjects following administration of 1 alpha-hydroxycholecalciferol (1 alpha-OHD3) at different doses. Large variations occurred indicating individual rates of metabolism of 1,25-(OH)2D.

Administration, Oral

Plasma 1,25-dihydroxyvitamin D levels in pregnancy and lactation.

Plasma concentrations of 1,25-dihydroxyvitamin D (1,25--(OH)2D), serum prolactin and serum parathyroid hormone (PTH) were followed during pregnancy and lactation in 16 women. High 1,25--(OH)2D was demonstrated in human pregnancy and lactation. A causative relationship between 1,25--(OH)2D and prolactin is discussed and a possible explanation of the mechanism of the augmented calcium absorption in human pregnancy and lactation is suggested.

Calcium

Measurement of 25-hydroxyvitamin D in serum and its relation to sunshine, age and vitamin D intake in the Danish population.

A competitive protein-binding assay for 25-hydroxyvitamin D (25-OHD) based upon a specific binding protein in the cytosol from rachitic rat kidneys is described. A diethyl ether extraction followed by separation by freezing was used. The extracts were chromatographed on short silicic acid columns, which separated 25-hydroxycholecalciferol from cholecalciferol, 24,25-dihydroxycholecalciferol, and 1,25-dihydroxycholecalciferol. A small aliquot of the 25-OHD fraction was used in the assay and free and bound vitamin were separated by dextran coated charcoal. The lower detection limit was 0.8 ng/ml (2.0 nmol/l). The levels of 25-OHD were measured in 596 healthy subjects and a seasonal variation was demonstrated. This variation, however, was only found in those without regular vitamin D intake, whereas the level of 25-OHD remained constant throughout the year in subjects with regular vitamin D supplement. The levels of 25-OHD were lower in the elderly subjects compared to younger ones, but seasonal variation was observed in both groups. In the summer months there was a significant correlation between age and the 25-OHD level. The mean levels of 25-OHD in Denmark are within the range of means found in the United States and Sweden but are higher than those reported from England, Belgium and France. This indicates a relatively high vitamin D intake in the Danish population and a low risk of nutritional vitamin D deficiency.

Adolescent

Vitamin D and ischaemic heart disease.

Vitamin D has been proposed as a risk factor of ischaemic heart disease. In 12 patients with acute myocardial infarction the major circulating vitamin D metabolite, 25-hydroxy-cholecalciferol (25-HCC), did not show any fluctuations during the first 4 days after onset of symptoms. The serum 25-HCC level was then measured in 128 patients consecutively admitted because of chest pain, 53 of whom had myocardial infarction and 75 had angina pectoris. The values found did not differ from those measured in 409 normal persons. The seasonal variations of serum 25-HCC were less pronounced in heart patients than in normals, probably due to less sun exposure in the summer months. The levels of serum 25-HCC did not correlate with the concentrations of serum cholesterol, glycerides, calcium or magnesium. Low serum calcium and magnesium were observed in all patients. Serum calcium was further reduced in the course of acute myocardial infarctions while serum parathyroid hormone rose significantly. We conclude that patients with ischaemic heart disease are not ingesting or producing in their skin elevated amount of vitamin D.

Alkaline Phosphatase

Effect of a low protein diet on in vitro protein synthesis in thymus, spleen, and bone marrow in young adult rats.

Young adult rats (body weight 90 g) were given a low protein (3% casein) diet for 6 days. Under these conditions, thymus and spleen organ wet weights and DNA content decreased as compared with control rats given a high protein (20% casein) diet. The in vitro incorporation of amino acids into protein was followed using leucine as the radioactive precursor. Ribosomes of tissues from the dietary rats were incubated together with soluble enzymes from liver of rats fed a stock diet, and cofactors. Ribosomal capacity for leucine incorporation into protein diminished in thymus by 33% per mg ribosomal RNA, 77% per total ribosomal RNA, and 43% per mg DNA. In spleen the corresponding reductions were 29%, 81%, and 31%; in bone marrow the decrease was 29% per mg ribosomal RNA, 56% per total ribosomal RNA, and 19% per mg DNA. A reduction in physiological activity is thus evident in these tissues soon after protein restriction.

Amino Acids

Fresh autotransfusion in major surgery.

The purpose of this study was to investigate whether 600-800 ml of fresh autologous blood, withdrawn just before anesthesia and retransfused at the end of the operation, would reduce early postoperative anemia. Thirty-nine patients undergoing abdominal hysterectomy were autotransfused, while 44, submitted to the same operation, served as controls. Appropriate amounts of lactated Ringer solution were infused during phlebotomy and operation. The cardiovascular system remained stable and diuresis high. Postoperative complications were few and did not prolong hospitalization. The mean peroperative blood loss per patient was 680 ml. Fresh autotransfusion did not improve early postoperative anemia.

Anemia

Neonatal hypocalcaemia associated with maternal hyperparathyroidism. New pathogenetic observations.

A 32-day-old male infant had hypocalcaemic convulsions associated with asymptomatic maternal hyperparathyroidism. Very low total and ionised serum calcium, increased serum phosphate, and normal serum parathyroid hormone (PTH) and 25-hydroxycholecalciferol (25-OHD3) concentrations were found at admission. After treatment with calcium and vitamin D, serum PTH and 25-OHD3 concentrations increased markedly before serum calcium levels returned to normal perhaps indicating an inability to convert 25-OHD3 to the metabolically active 1,25-dihyroxyvitamin D3 during the hyperphosphataemic state. Treatment with 1,25-dihdroxyvitamin D3 or its analogues is recommended.

Calcium

Evaluation of fracture healing in man by serial 99mTcSn-pyrophosphate scintimetry.

Serial 99mTc-pyrophosphate (99mTcPP) uptake measurements were performed, during the healing period, in 12 patients with fracture of the distal end of the radius without displacement. A peak value in uptake ratio was seen within 4 weeks in all patients. For clinical reasons the patients were divided into a normal healing and a slow healing group. 99mTcPP uptake at 6 weeks after the fracture was significantly higher in the slow healing group. Quantitation of the healing process in forearm fractures is possible using 99mTcPP and a gamma camera, and concentrating on small selected areas of interest.

Adult