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Biomedical subjects

F Melsen

Publications and source records attributed to F Melsen.

At least 163 records · Page 9Linked to original sources
PubMed1977

Bone disease, hypophosphatemia and hyperparathyroidism after renal transplantation.

UNLABELLED: Long-term survivors after renal transplantation (RT) show: 1) decreased s-phosphorus 2) increased s-PTH 3) no correlation between s-PTH and s-phosphorus 4) increased amount of non-mineralized bone (osteomalacia), inversely correlated to s-phosphorus 5) decreased amount of trabecular bone (osteopenia) in RT patients with aseptic necorsis of bone. CONCLUSION: aseptic necrosis of bone after RT is mainly due to osteoid-induced osteopenia, perhaps aggravated by hypophosphatemic osteomalacia.

Adolescent↗
PubMed1977

Morphometric and dynamic studies of bone changes in hyperthyroidism.

Bone biopsies were performed after tetracycline double-labelling by transfixing the right iliac crest in forty hyperthyroid patients. The bone changes in cortical and trabecular bone were determined by simple measurement and point counting on decalcified and undecalcified stained sections. A slight decrease in the amount of cancellous bone was found. The mean cortical width was normal. The amount of osteoid and the length of the osteoid seams were increased, whereas the mean width of osteoid seams was decreased. The cortical osteoclastic activity and porosity were markedly increased. The trabecular osteoclasic activity was moderately increased and the mean size of periosteocytic lacunae was slightly increased. The calcification rate in cancellous bone was increased as were the active calcification surfaces (tetracycline-labelled). The osteoclastic activity in cortical bone was positively correlated to the free thyroxine index and to the urinary calcium and phosphorus excretion. The findings indicate that the bone changes in hyperthyroidism are specific and that thyroid hormone(s) stimulates both bone formation and resorption followed by increased porosity in cortical bone and by mobilization of bone mineral.

Adolescent↗
PubMed1977

Effect of long-term vitamin D2 treatment on bone morphometry and biochemical values in anticonvulsant osteomalacia.

Quantitative morphometric analyses of iliac crest biopsies from 20 epileptic patients receiving chronic anticonvulsant therapy have been performed before and after 4-8 months of vitamin D2 treatment with 9 000 U per day. Biochemical quantities, including serum 25-hydroxycholecalciferol (25-HCC) and serum parathyroid hormone (iPTH), were measured. The anticonvulsant osteomalacia found in the initial bone biopsies was characterized by an increased amount of ummineralized bone, an increased bone resorption and, contrary to vitamin D deficiency, an increased bone mineralization and bone formation. Bone resorption and bone formation were probably equally increased since the amount of cancellous bone was normal. Except for a slight increase in osteoidcovered surfaces and osteoclastic resorption surfaces, the bone changes were normalized after vitamin D2 treatment, leading to a mean serum level of 25-HCC 2.4 times above normal. Serum iPTH was normal before and unchanged during D2 therapy. The urinary calcium excretion remained decreased. The investigation characterizes anticonvulsant osteomalacia as a specific bone disease different from that of vitamin D deects of vitamin D metabolites on receptor cells.

Adult↗
PubMed1977

Aseptic necrosis of bone following renal transplantation. Clinical and biochemical aspects and bone morphometry.

Aseptic necrosis of bone has developed 5--48 months (mean 23) after renal transplantation in 22 (11%) of 195 patients with graft function for more than 6 months. The bone lesions were mainly localized to weight-bearing cancellous bone areas, most often the femoral heads. The mean duration of hemodialysis was significantly longer in recipients with aspetic necrosis than in those without. The serum concentration of phosphate was reduced and the serum concentration of parathyroid hormone increased in both groups of recipients. Quantitative histological examination of iliac crest biopsies showed a pronounced reduction of spongy bone (osteopenia) in recipients with aseptic necrosis compared with both normals and recipients without aseptic necrosis. Both patient groups showed similar changes in bone remodelling, indicating decreased bone formation. These findings suggest that osteopenia is an important contributory factor in the development of aseptic necrosis of bone after transplantation. The osteopenia may be a consequence of both the uremic bone disease before transplantation and the immunosuppressive treatment after transplantation.

Adolescent↗
PubMed1977

Bone histomorphometry in patients with chronic renal failure: effect of 1alpha-hydroxyvitamin D3.

Morphometric and dynamic studies of iliac crest bone biopsies were carried out in twelve patients with chronic renal failure (six on chronic haemodialysis and six with renal insufficiency) before and after 6 months of 1alpha-hydroxyvitamin D3 treatment. Pre-treatment biopsies showed signs of osteomalacia and hyperparathyroidism. Biopsies taken during treatment showed changes towards normality, indicating a beneficial effect of 1alpha-hydroxyvitamin D3.

Adult↗
PubMed1977

Effect of 1alpha-hydroxyvitamin D3 on parathyroid function in patients with chronic renal failure.

The effect of 1alpha-hydroxyvitamin D3 (1alpha-OHD3) on parathyroid function was studied in sixteen patients (ten on haemodialysis, six with chronic renal insufficiency) during treatment for 6--8 months. During treatment, a decrease in serum parathyroid hormone (s-PTH) and an increase in serum calcium were seen. An inverse linear correlation was found between serum calcium and logarithmic values of s-PTH in fifteen of sixteen patients, but the slopes of the regression lines varied considerably. This indicates that the suppression of parathyroid function seen during treatment with 1alpha-OHD3 is mediated by a rise in the serum concentration of calcium. For normalization of s-PTH, the serum concentration of calcium had to be above normal range in several patients, indicating a defect in calcium-mediated regulation of the secretion of parathyroid hormone. This abnormality was seen especially in long-term haemodialysed patients.

Adolescent↗
PubMed1977

Treatment of senile osteoporosis with 1alpha-hydroxyvitamin D3.

About 30% of patients with clinical osteoporosis had histological signs of osteomalacia, in spite of normal serum 25-hydroxyvitamin D3 (25-OHD3). The excess osteoid disappeared during treatment with 1alpha-hydroxyvitamin D3 (1alpha-OHD3). These patients might have reduced ability to convert 25-OHD3 to 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3). The intestinal calcium absorption increased during treatment with 1alpha-OHD3, but this was accompanied by a rise in urinary calcium excretion. Photon absorptiometry of the forearm indicated increased bone mineral content during treatment with a daily dose of 2 microgram 1alpha-OHD3 and a supplement of 1 g of calcium. This therapeutic combination, however, caused frequent episodes of hypercalcaemia, so further studies are necessary to evaluate an appropriate dose of 1alpha-OHD3 with or without a calcium supplement.

Aged↗
PubMed1977

The interrelationships between serum 25-hydroxycholecalciferol, serum parathyroid hormone and bone changes in anticonvulsant osteomalacia.

Serum 25-hydroxycholecalciferol (25-HCC) and serum parathyroid hormone (iPTH) were measured in 59 randomly selected adult epileptic outpatients receiving chronic anticonvulsant therapy. Quantitative morphometric analysis of iliac crest biopsies was performed. A mild degree of osteomalacia was found which was inversely correlated to dietary vitamin D intake. Serum 25-HCC was reduced in the epileptic patients compared to a control group, although dietary intake of vitamin D was higher than the mean daily intake in the Danish population. Serum 25-HCC was positively correlated to dietary vitamin D intake, but not correlated to the severity of bone changes, indicating that other factors than circulating 25-HCC are responsible for the development of anticonvulsant osteomalacia. Serum 25-HCG was inversely correlated to serum iPTH in patients with a low dietary calcium intake. The mean value of serum iPTH was not increased, and there was no correlation between serum iPTH and bone morphometry.

Adolescent↗
PubMed1977

Bone changes in hyperthyroidism: interrelationships between bone morphometry, thyroid function and calcium-phosphorus metabolism.

Iliac-crest biopsies were obtained from 40 untreated hyperthyroid patients after double-labelling with tetracycline. Histomorphometric analyses were performed on undecalcified and decalcified bone sections. The morphometric and chemical data were compared with those in normal control groups and the results of the morphometric analyses were related to thyroid function and to chemical quantities of calcium-phosphorus metabolism. The bone turn-over was increased in the hyperthyroid patients with an increase both in bone resorption and bone formation. Serum alkaline phosphphatase was increased and positively correlated to the amount of osteoid and to the extent of tetracycline-labelled surfaces. The osteoclastic resorption was positively and the bone formation inversely correlated to thyroid activity. This might explain the reduced amount of trabecular bone found in hyperthyroidism. The most striking feature was, however, a pronounced increase in osteoclastic activity in cortical bone followed by increased porosity. The osteoclastic resorption in cortical bone was positively correlated to serum concentrations and urinary excretions of calcium and phosphorus. This indicates that increased cortical osteoclastic resorption is mainly responsible for bone mineral mobilisation in hyperthyroidism.

Adolescent↗
PubMed1977

Osteonecrosis following renal allotransplantation. A quantitative histological study of iliac bone.

Morphometric and dynamic studies of bone obtained by biopsy from a standard locality on the iliac crest were carried out in 10 patients with and 7 patients without radiological signs of osteonecrosis. All the patients had normally functioning kidney transplants. The results obtained in the two groups were compared and both groups were compared with a series of noraml subjects where the age and sex distribution was the same. In the group of patients with osteonecrosis, the reduction in the amount of cancellous bone was found to be highly significant as compared with that in normal subjects and with that in the other group of patients. Apart from the reduction in bone, changes in all patients were characterized by an increased amount of osteoid and a low rate of mineralization, determined by double labelling with tetracycline. As there were no changes in the width of osteoid seams indicating osteomalacia, it is suggested that these patients suffered from a severe corticosteroid osteopenia.

Adult↗
PubMed1977

Bone lesions following renal transplantation. Bone mineral density and amount of trabecular bone.

24 renal transplanted patients who developed post-transplant bone complications (aseptic necrosis of bone of spontaneous fractures) were studied and compared with a control material of age- and sexmatched renal transplanted (RT) patients. The bone mineral concentration in the forearm, histomorphometric measurements of iliac crest biopsies, and the parathyroid function were investigated. A significant reduction in the bone mineral concentration was found in the group of RT patients with bone complications compared to RT patients without. The amount of cancellous bone in the bone biopsies was reduced in patients with aseptic necrosis of bone. No significant differences in the biochemical values were found.

Adult↗
PubMed1976

Anticonvulsant osteomalacia determined by quantitative analysis of bone changes. Population study and possible risk factors.

Material has been obtained by biopsy from the right iliac crest of 60 adult epileptic out-patients receiving chronic anticonvulsant therapy with diphenylhydantoin (DPH), either in single-drug or combined-drug regime, and of 16 controls with the same distribution by sex and age. Four (7%) of the epileptics were hypocalcemic and 25 (42%) had elevated serum alkaline phosphatase values. A quantitative analysis of the morphological bone changes was performed on decalcified and undecalcified bone, using integrating filters and the point count principle. An increased amount of unmineralized bone was found in 32 (53%) of the epileptics. The trabecular osteoclastic resorption surfaces and the mean volume of periosteocytic lacunae were increased in 36 (69%) and 45 (75%) patients, respectively. The calcification rate was decreased in relation to what is referred to elsewhere as normal. The bone changes suggest a mineralization defect analogous to osetomalacia with secondary hyperparathyroidism. An increased osteoid volume or thickness and decreased calcification rate were correlated to low dietary vitamin D intake, low exposure to sunlight, high hepatic clearance rate of DPH, combined-drug treatment and the male sex. These parameters should be considered risk factors of anticonvulsant osteomalacia.

Adolescent↗
PubMed1976

The relation between densitometric and quantitative histological analysis of bone specimens from the iliac crest.

Roentgendensitometric measurements were correlated with quantitative histological analysis of cortical and cancellous bone from a standard anatomical site on the iliac crest. The point-count method was used to quantitate spongy bone in 8 mu thick sections. Measurements of the thickness of the cortices were made with a micrometric eyepiece. The reproducibility of the method for the roentgendensitometric analysis was found to be about 1 per cent of the mean for all variables. The correlation between roentgendensitometric and histological analysis was found to be low (r=0.44) and could be ascribed mainly to variation in the thickness of the cortices which again was only slightly correlated with the percentage of spongy bone (r=0.39). Both the determination of the amount of bone mineral and of bone by quantitative histometric analysis are required for diagnosis of skeletal system disorders.

Absorptiometry, Photon↗