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Biomedical subjects

G Heynen

Publications and source records attributed to G Heynen.

At least 73 records · Page 4Linked to original sources
PubMed1978

Biological activity of endogenous and exogenous calcitonin in patients with osteitis fibrosa and chronic renal failure.

Successful treatment of osteitis fibrosa with 1alpha-hydroxycholecalciferol (1alpha-OHD3) in 9 patients with end-stage chronic renal failure was associated with a significant increase in plasma levels of immunoreactive calcitonin (iCT) independently of changes in plasma calcium, and a decrease in levels of parathyroid hormone (iPTH). In 9 further patients whose plasma alkaline phosphatase activity failed to suppress with 1alpha-OHD3, changes in iPTH were associated with proportionate changes in iCT. This suggests that a rise in endogenous calcitonin (CT) secretion contributes to the success of treatment with 1alpha-OHD3. In 13 further patients, injections of salmon CT induced a fall in plasma calcium and phosphate which was proportional to the prevailing level of plasma alkaline phosphatase. These data provide further evidence that bone resorption can be effectively inhibited when CT levels are raised either by exogenous CT or its endogenous stimulation.

Alkaline Phosphatase↗
PubMed1977

Changes in histologic and biochemical indexes of bone turnover after bilateral nephrectomy in patients on hemodialysis. Evidence for a possible role of endogenous calcitonin.

We studied the effects of bilateral nephrectomy on bone metabolism in 27 patients on maintenance hemodialysis. After nephrectomy plasma alkaline phosphatase fell rapidly in 10 patients whose preoperative plasma levels had been higher than normal. This fall was associated with a transient decrease in osteoblast counts of iliac-bone biopsies. A fall in plasma phosphate and a rise in plasma immunoreactive calcitonin also occurred, but calcium and immunoreactive parathyroid hormone levels did not change. Alkaline phosphatase levels remained unchanged in a control group of 17 patients on dialysis who had undergone an operation other than nephrectomy. In 26 nonsurgical patients on dialysis, immunoreactive calcitonin was inversely related to osteoblast counts. Rises in immunoreactive calcitonin may be partly responsible for the transient decreases in bone turnover after bilateral nephrectomy. Low levels of endogenous calcitonin may allow an increase in bone turnover in chronic renal failure.

Adolescent↗
PubMed1977

Plasma calcitonin in Paget's disease of bone.

1. Plasma levels of immunoreactive calcitonin were measured in 22 patients with untreated Paget's disease of bone and in 22 control subjects matched for age and sex. 2. No significant differences in plasma calcitonin were found between patients and control subjects, and hormone levels did not correlate significantly with activity of plasma alkaline phosphatase. 3. These results suggest that Paget's disease of bone is not due to deficient of endogenous calcitonin.

Aged↗
PubMed1977

Correlation of clinical, biochemical and skeletal responses to 1alpha-hydroxyvitamin D3 in renal bone disease.

Thirty-five patients with bone disease and chronic renal failure (twenty-four on maintenance haemodialysis) were treated for 7--39 months with 1alpha-hydroxyvitamin D3, 2--2.5 microgram daily by mouth. Symptoms (bone pain and muscle weakness) and radiographic appearances improved and plasma alkaline phosphatase returned to normal in the majority of patients (87, 76 and 75% respectively). In contrast, histological appearances in bone improved in only 46% twenty-three patients from whom paired biopsies were available, and this change was not greatly different from that seen in a comparable group of untreated patients. Significant correlations were noted in individual patients between the changes in symptoms, X-rays, plasma alkaline phosphatase and immunoreactive parathyroid hormone and these, in turn, were related to histological changes in bone, although these latter changes were often small. It is concluded that 1alpha-hydroxyvitamin D3 is a useful new drug in the treatment of renal bone disease, but that the evaluation of the response depends critically on the method of assessment used.

Adolescent↗
PubMed1977

Factors influencing the response to 1alpha-hydroxyvitamin D3 in patients with renal bone disease.

Twenty-three patients with bone disease and chronic renal failure were treated for periods of 4--28 months with 1alpha-hydroxyvitamin D3 (1alpha-OHD3). Improvements in bone histology were consistently seen in patients with features both of osteitis fibrosa and osteomalacia but were not invariably observed in patients with osteitis fibrosa or osteomalacia alone (37 and 50% improved respectively). Several factors influencing the outcome of treatment were assessed on the basis of histological responses in bone. A low level of plasma calcium before treatment, rather than the dose of 1alpha-OHD3 tolerated, was the major detectable factor which favourably affected the histological outcome. Other factors examined, including initial plasma concentrations of phosphate, immunoreactive parathyroid hormone and alkaline phosphatase, and treatment with haemodialysis or dietary supplements of calcium did not apparently influence the response.

Alkaline Phosphatase↗
PubMed1977

Measurement of whole body calcium in chronic renal failure: effects of 1alpha-hydroxyvitamin D3 and parathyroidectomy.

In vivo neutron activation analysis was used to measure changes in whole body calcium in patients with chronic renal failure. Eight patients, not treated by haemodialysis, showed losses of calcium in contrast to increases noted in twenty-one patients treated by haemodialysis. Changes in whole body calcium were independent of pre-existing renal bone disease. Treatment of bone disease by total parathyroidectomy (six patients) or 1alpha-hydroxyvitamin D3 (eleven patients) resulted in large increases in total body calcium. In patients given 1alpha-hydroxyvitamin D3, changes in total body calcium correlated with histological and radiological indices of response but variable changes in forearm bone mineral content were observed. Neutron activation analysis provides a convenient method for measuring skeletal mass and may also be useful in the assessment of response to 1alpha-hydroxyvitamin D3 of patients with osteitis fibrosa and osteomalacia.

Adult↗
PubMed1977

Renal osteodystrophy in nondialysed adolescents. Long-term treatment with 1alpha-hydroxycholecalciferol.

The effects of small oral doses (1-2 microgram/day) of 1alpha-hydroxycholecalciferol, given for 1 to 2 years, have been examined in four nondialysed adolescents with chronic renal failure and bone disease. Treatment increased calcium retention and plasma calcium, and decreased plasma levels of alkaline phosphatase, hydroxyproline, and immunoreactive parathyroid hormone. X-ray abnormalities of bone regressed, and 2 patients underwent successful surgical correction of knock-knees; bone histology in these 2 was normal at the time of operation. 2 patients developed hypercalcaemia which promptly reversed when 1alpha-hydroxycholecalciferol was withdrawn. In one patient treatment was initially successful, but later there was biochemical, radiographic, and histological evidence of relapse. Long-term treatment of such patients with 1alpha-hydroxycholecalciferol may be effective and facilitate the surgical correction of deformities, but this is not invariable. Toxic effects are similar to those of vitamin D itself, but are more readily reversible.

Adolescent↗