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J R Juttmann

Publications and source records attributed to J R Juttmann.

34 records · Page 2Linked to original sources
PubMed1983

Follow-up of long-term treatment of predialysis renal bone disease with 1-alpha-hydroxy-derivatives of vitamin D.

Patients with predialysis chronic renal failure and bone disease were treated with 1 alpha-hydroxy-derivatives of vitamin D. The observation period consisted of 22 patient years. All patients showed histological improvement of renal osteodystrophy after the initial 6 months of treatment. Bone resorption indices improved most strongly. There was also a considerable decrease of non-mineralized osteoid and no change in the total trabecular bone volume. Hypercalcemia occurred 24 times in 9 patients. Although in general the 1,25-(OH)2-vitamin D serum levels were increased at the time of hypercalcemia, as compared to the preceding non-hypercalcemic period, no elevation above the normal range occurred. In cases of hypercalcemia two different groups of patients, with suppressed and non-suppressed levels of iPTH respectively, could be distinguished. In both groups different significant correlations between serum 1,25-(OH)2-vitamin D and serum calcium levels were found. If serum iPTH was not suppressed hypercalcemia was more severe. It is concluded that the occurrence and severity of hypercalcemia in patients with chronic renal failure during treatment with 1 alpha-hydroxy-derivatives of vitamin D is related to the presence of parathyroid hormone.

Adult↗
PubMed1982

Short-term effect of prednisone on serum 1,25-dihydroxyvitamin D in normal individuals and in hyper- and hypoparathyroidism.

Oral administration of prednisone (30 mg/day for 9 days) to six normal individuals induced a significant rise in the concentration of serum 1,25-dihydroxyvitamin D [1,25-(OH)2D] within 2 days. In four patients with primary hyperparathyroidism a larger increase of 1,25-(OH)-2D was observed within 3 days. In these patients the 1,25-(OH)-2D concentration remained elevated during the whole period of prednisone administration (10 days) whereas in the control group it had returned to basal levels or below after 9 days of prednisone administration. This response appeared dependent upon parathyroid hormone (PTH) as we found no change in the (basally low) 1,25-(OH)2D concentrations in five patients with hypoparathyroidism during 3-4 days of prednisone administration (30 mg/day). In these patients vitamin D medication had been interrupted 3-5 days before the administration of prednisone, whereafter serum calcium was kept between 2.10 and 2.30 mmol/1 by means of calcium infusion. The response of 1,25-(OH)2D to prednisone is best explained by a stimulatory action of glucocorticoids upon PTH secretion or by the induction of increased PTH sensitivity.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

Seasonal fluctuations in serum concentrations of vitamin D metabolites in normal subjects.

Serum concentrations of 25-hydroxycholecalciferol (25-OHD), 24,25-dihydroxycholecalciferol (24,25-(OH)2D), and 1,25-dihydroxycholecalciferol (1,25-(OH)2D) were measured at monthly intervals throughout the year in eight normal subjects. 25-OHD was measured by competitive protein-binding assay after Sephadex LH 20 chromatography, 24,25-(OH)2D by competitive protein-binding assay after Sephadex LH 20 and high-pressure chromatography, and 1,25-(OH)2D by radioimmunoassay after the same separation procedure as for 24,25-(OH)2D. A seasonal variation, apparently dependent on exposure to ultraviolet light, was found for all three metabolites. A study in six other normal subjects showed that there was no diurnal rhythm in any of the metabolites. Oral administration of 2 microgram 1,25-(OH)2D caused a sharp rise in serum concentrations of 1,25-(OH)2D and no change in the concentrations of the two other metabolites, but by 12 hours the 1,25-(OH)2D concentration had returned to the basal value. The concentrations of all three metabolites studied vary according to the season. Thus to interpret these concentrations in any subject the normal range for the particular season must be referred to.

Adult↗
PubMed1981

Serum concentrations of metabolites of vitamin D in patients with chronic renal failure (CRF). Consequences for the treatment with 1-alpha-hydroxy-derivatives.

In forty-two patients with chronic renal failure (CRF), serum concentrations of 25-hydroxy-cholecalciferol (25-OHCC), 24,25-dihydroxy-cholecalciferol (24,25-OH2CC) and 1,25-dihydroxy-cholecalciferol (1,25-OH2CC) were measured before and during intermittent haemodialysis (IHD) and in a few cases also after renal transplantation. 25-OHCC and 24,25-OH2CC were measured by means of a competitive protein binding assay after Sephadex LH20 chromatography and 1,25-OH2CC by means of a radioimmunoassay after Sephadex LH20 and high pressure liquid chromatography (HPLC). In our patients serum values for 25-OHCC and 24,25-OH2CC showed a seasonal fluctuation as in normal individuals. The concentrations in the serum of 24,25-OH2CC and 1,25-OH2CC showed a positive correlation with renal function. With regard to 24,25-OH2CC this correlation was only found for the 24,25-OH2CC:25-OHCC ratio which was used to eliminate the seasonal fluctuation. For both dihydroxylated metabolites subnormal concentrations were found when the creatinine clearance was 40-50 ml/min and lower. It appears that the decrease of the plasma level of these metabolites of Vitamin D precedes (or is concomitant with) the changes in the serum values of calcium (Ca), phosphorus (P) and parathyroid hormone (PTH) and the diminution of the intestinal absorption of Ca. These findings indicate that patients with CRF should be treated at an early stage of the disease with 1 alpha-hydroxy-derivatives of Vitamin D in order to prevent the development of, or to induce the healing of, bone-lesions of renal osteodystrophy.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

Lack of response of 1,25-dihydroxycholecalciferol to exogenous parathyroid hormone in a patient with treated pseudohypoparathyroidism.

The response of serum 1,25-dihydroxycholecalciferol (1,25-OH2CC) concentration to the administration of parathyroid extract (PTE) was studied in a patient with pseudohypoparathyroidism (PHP) type 1, 3 days after withdrawal of dihydrotachysterol (DHT) treatment. The patient had had a normal serum calcium (Ca), phosphorus (P) and immunoreactive parathyroid hormone (iPTH) level on DHT for 6 years. After PTE administration no rise of the 1,25-OH2CC concentration and no response of urinary cAMP and P were seen.

Adult↗
PubMed1979

A longitudinal study of bone-mineral content and intestinal calcium absorption in patients with chronic renal failure.

In 14 nondialyzed patients with chronic renal failure (CRF) and at the start of treatment a glomerular filtration rate (GFR) of 14--47 ml/min changes in bone mineral mass (BMM), expressed in percentage of the initial value, showed a significant correlation with the mean GFR during an observation period of 16 +/- 2 mo. During a predialysis period of 6 mo BMM decreased to 97.8 +/- 3.2% of the original value in 9 patients, while after 6, 12, and 16 mo of dialysis treatment, BMM in the same patients fell to 94.5 +/- 3.0%, 92.0 +/- 3.2% and 91.8 +/- 4.6% of the initial value. As after the onset of regular hemodialysis the fractional intestinal absorption of 47Ca does not decrease but even increases in most patients, the importance of the level of intestinal calcium absorption for the development of dialysis bone disease may be questioned.

Adult↗
PubMed1978

Intestinal calcium absorption, serum phosphate, and parathyroid hormone in patients with chronic renal failure and osteodystrophy before and during hemodialysis.

In 34 patients with chronic renal failure (CRF), fractional 47calcium absorption (Fa47Ca) was measured by an external counting method. A significant correlation was found with impairment of renal function, as expressed by the creatinine clearance. There was also a significant correlation of Fa47Ca with the serum phosphate (SeP) level and of immunoreactive parathyroid hormone (iPTH) with renal function. When the relationship of both SeP and Fa47Ca with creatinine clearance was excluded, no partial correlation between SeP and Fa47Ca appeared to exist. A significant increase of Fa47Ca and serum Ca and a significant decrease of SeP and iPTH were found in 12 patients 2 to 15 months after they were put on intermittent hemodialysis. The possible influence of SeP on intestinal calcium absorption is discussed, and it is suggested that impairment of intestinal absorption of calcium is not a main factor in development of renal osteodystrophy.

Adolescent↗
PubMed1978

A comparative study of two methods of measurement of fractional calcium absorption: results in normal individuals and patients with various disturbances of calcium metabolism.

Two methods of measurement of fractional calcium absorption have been compared in the same individuals. There is a significant correlation between fractional 47Ca absorption as measured with a blood counting method and with an external counting method after intravenous and oral administration of 47Ca (P less than 0.001). Two varieties of the external counting method, namely with intervals of 2 h and 7 days between the i.v. and oral doses, have been compared. In a group of twenty-one patients with chronic renal failure (not on haemodialysis), 47Ca absorption as measured by external counting was significantly lower than in the control group (P less than 0.001). When put on a dialysis programme a group of six patients showed a significant increase of the fractional 47Ca absorption (P less than 0.01).

Absorption↗
PubMedDate not supplied

Comparison of two once-daily regimens with a regimen consisting of nelfinavir, didanosine, and stavudine in antiretroviral therapy-naïve adults: 48-week results from the Antiretroviral Regimen Evaluation Study (ARES).

BACKGROUND: To improve the dosing frequency and pill burden of antiretroviral therapy, we compared two once-daily dosed regimens to a twice-daily dosed regimen. METHOD: HIV-1-infected, antiretroviral drug-naïve adults were randomized to either twice-daily nelfinavir and stavudine and once-daily didanosine (regimen A) or simplified once-daily dosed antiretroviral regimens consisting of nevirapine, didanosine, and lamivudine (regimen B) or saquinavir, ritonavir, didanosine, and lamivudine (regimen C). RESULTS: At 48 weeks of therapy, the proportion of patients with a blood plasma HIV-1 RNA concentration (pVL) <50 copies/mL by intention-to treat analysis was 42.3%, 50.0%, and 56.5% for regimens A (n = 26), B (n = 22), and C (n = 23), respectively. The time to a pVL <50 copies/mL for the first time was significantly shorter in regimen C, and there was significantly more progression to CDC events in regimen B. These differences are possibly due to differences in baseline characteristics. Adverse events were lowest for regimen C; more signs associated with mitochondrial toxicity occurred in regimen A. Increase in CD4 count was comparable between arms. CONCLUSION: No statistically significant difference in efficacy was found between the two investigated once-daily dosed treatment regimens (B and C) and the reference (A). Regimen C possibly had a better virological response and less toxicity than regimens A and B.

Adult↗