PubMed Health⌕ Search

Biomedical subjects

J Ladefoged

Publications and source records attributed to J Ladefoged.

At least 109 records · Page 6Linked to original sources
PubMed1978

Calcium-dependent aldosterone secretion in anephric and nonnephrectomized patients on regular hemodialysis.

The present study was undertaken to investigate the effect of a continuous calcium infusion on the plasma levels of aldosterone, renin activity, and cortisol in six anephric and four nonnephrectomized patients on regular hemodialysis. In both groups, a significant increase in whole blood ionized calcium (b-Ca2+) was demonstrated. A significant increase in plasma aldosterone (PAC) was noted in the nonnephrectomized patients, in whom the rise in PAC correlated with the increase in b-Ca2+. However, in the anephric patients only a smaller and insignificant increase in PAC was found. No significant changes were demonstrated in plasma cortisol or renin activity, nor in potassium or sodium concentrations in either group. It is concluded that ionized calcium influences the plasma levels of aldosterone in uremic patients on regular hemodialysis.

Adrenocorticotropic Hormone↗
PubMed1978

Cessation of bone loss in chronic renal failure by 1-alpha-hydroxyvitamin D3: a controlled trial.

The study was undertaken in patients with chronic renal failure (CRF patients) in order to evaluate 1) the degree and course of skeletal demineralisation and 2) the effect on the bone mineral content (BMC) of long-term treatment with 1alpha-hydroxyvitamin D3 (1alpha(OH)D3). BMC was measured on the radius by 241 Am-photonabsorptiometry and the results were corrected for age, sex and bone width. In a cross-sectional study BMC was measured in 191 normal subjects and in 88 renal patients. In a controlled longitudinal trial 22 CRF patients were treated for 25.6 months with 1alpha(OH)D3, while 22 CRF patients did not receive vitamin D supplements. In CRF patients an accelerated bone loss (approximately 3%/year) and a significantly reduced BMC (mean 87.2% of normal) was found. In the 1alpha(OH)D3 treated patients BMC increased on an average 0.9%/year. This was significantly different from the continued bone loss recorded in the non-treated control patients. The data indicate that 1) CRF patients develop reduced bone mass because of accelerated bone loss; 2) cessation of this bone loss may be achieved by long-term treatment with 1alpha(OH)D3.

Adult↗
PubMed1977

The maximal tubular reabsorption of phosphate in relation to serum parathyroid hormone.

The relation between the renal handling of phosphate and the serum concentration of immunoreactive parathyroid hormone (i-PTH) was investigated in 15 patients with a very wide range of i-PTH, glomerular filtration rate (GFR), maximal tubular reabsorption of phosphate (TmP) and TmP/GFR-ratio. The latter was used as an index of the renal handling of phosphate. Seven patients had well functioning kidney allografts (GFR 43.1-64.9 ml/min), while 8 had varying degrees of chronic nephropathy (GFR 2.3-26.7 ml/min). The TmP, i-PTH, 51Cr EDTA clearance, the extracellular volume and serum concentrations of calcium and standard bicarbonate were estimated. An inverse significant correlation was demonstrated between TmP/GFR and i-PTH (p less than 0.001), while none of the other investigated factors correlated thyroid hormone has a key role in the regulation of the tubular handling of phosphate in patients with impaired renal function.

Adult↗
PubMed1977

Plasma aldosterone during extracellular fluid volume expansion in patients on regular haemodialysis.

The influence of extracellular fluid volume expansion on the plasma aldosterone concentration (PAC) was investigated in five anephric and six non-nephrectomized patients on regular haemodialysis, and compared to a control group of four anephric and four non-nephrectomized patients. Plasma-renin activity, cortisol, Na+, and K+ were measured together with the PAC during the investigation. In anephric patients the PAC remained constant during the control period as well as during extracellular fluid volume expansion by infusion of 350 mmol of 20% mannitol. In the non-nephrectomized patients PAC diminished after mannitol infusion. The decline in PAC was correlated with the basal levels of PAC and the plasma renin activity. It is concluded that 5% extracellular fluid volume expansion has no direct influence on the regulation of PAC in patients without the renal renin-angiotensin system and that the regulation of PAC in anephric patients in the present investigation is probably mediated by changes in potassium and ACTH.

Adult↗
PubMed1976

Treatment of acute allograft rejection with high doses of corticosteroids.

Sixty-four rejection crises in 55 kidney transplant patients were treated with high doses of corticosteroids, either 1) prednisone, administered orally in doses ranging between 150 and 600mh/day;2)methylprednisolone, administered i.v. in doses of 0.5 to 1 g/day (total dose: 2 to 8 g); or 3) methylprednisone administered i.v. in the same dosage in combination with heparin 5000 U/day. Acute rejection was reversed successfully in 60% of the crises without any apparent difference between the three treatment groups. Nineteen patients died from steroid-related complications. A total methylprednisolone dosage exceeding 3 to 5 h apparently was not accompanied by a sufficiently improved therapeutic response to warrant the high risk of such treatment.

Acute Disease↗
PubMed1976

Renal handling of phosphate in relation to serum parathyroid hormone levels.

The relation between the renal handling of phosphate, expressed as the maximal tubular reabsorption of phosphate (TmP)/glomerular filtration rate (GFR) index, and the serum concentration of immunoreactive parathyroid hormone (i-PTH) has been ivestigated in 15 patients with a very wide range of GFR, TmP/GFR and i-PTH. Seven patients had well functioning kidney allografts, with GFR ranging from 43.1 to 64.9 ml/min, while eight had varying degrees of chronic nephropathy, with GFR ranging from 26.7 to 2.3 ml/min. The TmP, the i-PTH concentration, the 51Cr EDTA clearance, the extracellular volume and the serum concentrations of calcium and standard bicarbonate were estimated during conditions where tubular reabsorption of phosphate was maximal. An inverse significant correlation was demonstrated between TmP/GFR and i-PTH (p less than 0.001), while none of the other investigated factors correlated to the TmP/GFR index. It is therefore concluded that the parathyroid hormone has a key role in the regulation of the tubular handling of phosphate in patients with impaired renal function.

Adult↗
PubMed1976

1-Alpha-hydroxycholecalciferol-induced changes in the renal heandling of phosphate and the serum parathyroid hormone level.

The effect of 1-alpha-hydroxycholecalciferol (1alpha-OH-D3) on the renal handling of phosphate and the immunoreactive parathyroid hormone in serum (i-PTH) has been studied in 10 patients with a wide range of glomerular filtration rate (GFR), maximal tubular reabsorption of phosphate (TmP) and i-PTH. The patients were treated with 2 mug 1alpha-OH-D3 per day for approximately 80 days. Before and after this period of treatment, the TmP, i-PTH, 51Cr EDTA clearance, extracellular volume, standard bicarbonate, and serum calcium were measured in each patient. The TmP/GFR ratio was used as an index of the renal handling of phosphate. The index increased significantly (mean 26.5%, p less than 0.01) during the treatment, while i-PTH decreased significantly (mean 37.0%. p less than 0.01). An inverse significant correlation was demonstrated between TmP/GFR index and i-PTH both before (r = -0.87, p less than 0.001) and after (r = -0.79, p less than 0.01) the administration o alpha-OH-D3, while none of the other factors investigated were correlated to the index. It is concluded that 1alpha-OH-D3 increases the TmP/GFR index and reduces i-PTH in a parallel manner and it is therefore suggested that the 1alpha-OH-D3-induced changes in the renal handling of phosphate may be explained as being mediated solely via the suppression of i-PTH.

Administration, Oral↗
PubMed1976

1alpha-hydroxycholecalciferol. Long-term treatment of patients with uraemic osteodystrophy.

Three adolescents with uraemic osteodystrophy were treated for 7 months with daily oral doses of 1alpha-hydroxycholecalciferol (0.25-10.0 mug). All the patients were hypocalcaemic and had high serum levels of alkaline phosphatase before the treatment. A rapid rise in serum calcium and a slow, but pronounced decline in serum alkaline phosphatase concentration were observed during the period of treatment. 1alpha-Hydroxycholecalciferol induced hypercalcaemia in two situations. In both cases the hypercalcaemia was transient, serum calcium being normalized in a few days by withdrawal of the drug. Withdrawal of the drug also in other situations resulted in a fall in serum calcium concentration in a couple of days. This suggests that 1alpha-hydroxycholecalciferol should be given daily or every other day. The response did not subside during 7 months of treatment. On the contrary, the maintenance dose necessary to keep serum calcium constant was smaller than the initial dose necessary to normalize serum calcium. Bone mineral content, estimated by photon absorptiometry, rose. The rachitic bone lesions seen radiologically were significantly ameliorated during the treatment.

Adolescent↗
PubMed1976

Predictive value of renography and i.v. urography for the outcome of reconstructive surgery in patients with hydronephrosis.

Intravenous urography and isotope renography studies were made in 54 patients with hydronephrosis. Thirty six of these patients underwent reconstructive surgery and were also studied postoperatively. Both studies gave more or less consistent results - that is to say evaluations of renal function and drainage from each individual study were similar - but no individual parameter was of any specific significance in the selection of patients for therapy. Points were allocated to each parameter, and after summing these points for each individual patient, 3 groupings became apparent: a low count group - patients with pelvectasia but normal renal function:a middle count group - patients with certain hydronephrosis; and a high count group with severe hydronephrosis, and markedly impaired renal function. Post-operatively, renal function was unaltered or mildly reduced in group 1, and improved in groups 2 and 3, though the differences were not statistically significant. It was hoped that the studied would allow differentiation between patients of the low count group, but the conundrum remains - which of them can be categorized as normal variants, and which were in fact displaying early pathological signs of essentially progressive disease.

Adolescent↗