Search PubMed⌕ Search

Biomedical subjects

T Storm

Publications and source records attributed to T Storm.

At least 37 records · Page 2Linked to original sources
PubMed1992

Long-term suppression of secondary hyperparathyroidism by intravenous 1 alpha-hydroxyvitamin D3 in patients on chronic hemodialysis.

The effect of intravenous 1 alpha-hydroxyvitamin D3 [1 alpha(OH)D3] on circulating levels of intact parathyroid hormone (PTH 1-84) and COOH-terminal immunoreactive PTH(PTH 53-84) was examined in 13 patients on chronic hemodialysis. Thirteen patients were treated for 300 days (10 months), 9 patients for 520 days (14 months) and 6 patients for 720 days (2 years) with increasing doses of 1 alpha(OH)D3 intravenously under careful control of plasma Ca2+. Blood samples were obtained 1 week before start of treatment and then at every 2nd week. None of the patients had previously been treated with oral vitamin D metabolites. Intact PTH levels were maximally suppressed after 27-33 weeks of treatment by approximately 73%. At the end of the study periods, PTH 1-84 was still suppressed by 78 +/- 4.3% after 300 days, 78 +/- 8.8% after 520 days and 85 +/- 6.5% after 720 days. Plasma Ca2+ was kept within normal levels, but showed an initial increase from 1.14 +/- 0.03 to 1.27 +/- 0.15 mmol/l, and an adjustment of the doses of 1 alpha(OH)D3 was necessary. The present investigation demonstrated (1) that intravenous administration of the 1-hydroxylated vitamin D metabolite 1 alpha(OH)D3 induced a significant decrease in circulating levels of biologically active intact PTH, and (2) that it was possible to maintain the marked suppression of PTH secretion by intravenous treatment of 1 alpha (OH)D3 for up to 2 years. Hypercalcemia could be avoided by careful monitoring of plasma Ca2+ and adjustment of the doses of 1 alpha(OH)D3.

Adult↗
PubMed1991

Effect of a short course of 1,25-dihydroxyvitamin D3 on biochemical markers of bone remodeling in adult male volunteers.

To investigate the stimulatory effect of vitamin D on biochemical markers of bone remodeling, 15 normal men (aged 26-45 years, mean 33.2) were treated orally with 1,25-dihydroxyvitamin D3, 2 micrograms daily for 7 days, and followed for a total of 16 weeks. Serum concentrations of 1,25-dihydroxyvitamin D3 rose 43% during the first week (p less than 0.01), with no significant alteration in the level of 25-hydroxyvitamin D3. Serum level of immunoreactive parathyroid hormone (1-84) (iPTH) decreased markedly (p less than 0.02), and the maximal renal reabsorption capacity of phosphate (TmP/GFR) increased (p less than 0.05), both indicating the impact of the raised vitamin D level on target tissues. Serum phosphate and serum calcium increased during the treatment week (p less than 0.05), as did the fasting renal excretion of phosphate and calcium (p less than 0.01). However, a gradual fall in the excretion of hydroxyproline was seen in the observation period. The serum activity of acid phosphatase increased in the first weeks after vitamin D treatment, reaching significance at the end of week 2 (p less than 0.05). Acid phosphatase activity was still increased at the end of the observation period (p less than 0.02). These observations suggest a synchronization and recruitment of new bone resorptive cells. The immediate response to 1,25-dihydroxyvitamin D administration on the biochemical markers of formative bone cells was a marked increase in the serum level of osteocalcin (BGP), (p less than 0.002) with a gradually fall during the next weeks. A secondary increase, however, was observed in the last two months of the follow-up period.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1991

Bone disorder in men with chronic alcoholism: a reversible disease?

Disturbances in bone metabolism and histology have been recognized in chronic alcoholism. It has not been established whether they are reversible and the cause remains unclear. We studied various serum and urine variables (including serum PTH, calcium, D-vitamins, and osteocalcin concentrations), bone mineral content, and bone histomorphometrics in men who at present abused alcohol and compared the results to those from men who previously had abused alcohol but who had abstained from alcohol for at least 2 yr and from normal men. No significant differences were found in bone mineral content at the two measuring sites (distal forearm, lumbar spine) between drinkers, abstainers, and controls though a considerable proportion of both current drinkers and abstainers had subnormal values. Bone formation rate and turnover (expressed by the activation frequency) was significantly reduced in the current drinkers who also had lower serum PTH, 1,25-dihydroxycholecalciferol, and osteocalcin concentrations. Men who had abstained from alcohol consumption for at least 2 yr had results similar to those from normal men, suggesting that the disturbances in bone metabolism in men abusing alcohol are reversible. The decrease in bone turnover in the drinkers may be explained by the observed reduction in plasma PTH concentration or a direct toxic effect of ethanol on bone tissue leading to a deficient recruitment of osteogenic cells.

Alcoholism↗
PubMed1990

Effect of intermittent cyclical etidronate therapy on bone mass and fracture rate in women with postmenopausal osteoporosis.

Progressive bone loss in osteoporosis results from bone resorption in excess of bone formation. We conducted a double-blind study in 66 women with postmenopausal osteoporosis of therapy with etidronate, a diphosphonate compound that reduces bone resorption by inhibiting osteoclastic activity. The patients were randomly assigned in equal numbers to receive oral etidronate (400 mg per day) or placebo for 2 weeks, followed by a 13-week period in which no drugs were given. This sequence was repeated 10 times, for a total of 150 weeks. Daily oral supplementation with calcium and vitamin D was given throughout the study to both groups. Vertebral bone mineral content was measured by dual-photon absorptiometry; spinal radiographs were assessed to identify new vertebral fractures. Vertebral bone mineral content increased significantly (P less than 0.01) after 150 weeks of etidronate therapy (5.3 percent; 95 percent confidence interval, 2.0 to 8.6; n = 20) but decreased with placebo (-2.7 percent; 95 percent confidence interval, -7.3 to 1.9; n = 20). The difference between groups was 8.0 percentage points (P less than 0.01; 95 percent confidence interval, 2.4 to 13.6). The rates of fracture were significantly different for the period from week 60 to week 150 between the etidronate and placebo groups (6 vs. 54 fractures per 100 patient-years; P = 0.023). No adverse clinical, biochemical, or bone histomorphometric effects of treatment were observed. We conclude that at the end of nearly three years, etidronate therapy for postmenopausal osteoporosis results in significant increases in vertebral bone mineral content and, after approximately one year of treatment, a significant decrease in the rate of new vertebral fractures.

Administration, Oral↗
PubMed1989

Double-blind comparison of tiapamil and atenolol in patients with mild to moderate hypertension: a multicenter trial.

The efficacy and safety of tiapamil, a new calcium-channel blocker, was compared with the cardio-selective beta-blocker atenolol in a 16-week double-blind, multicenter trial with an initial 4-week placebo run-in period. Eighty-one outpatients with WHO stage I or II hypertension, 55 men and 26 women, entered the study. There was a total of nine drop-outs, six in the tiapamil group and three in the atenolol group. Five were due to side effects (four in the tiapamil group and one in the atenolol group). Sixty-one patients performed a graded exercise test sitting on a ergometer bicycle before and after completion of the therapy. Patients eligible for the study after the placebo period received either tiapamil 450 mg b.i.d. or atenolol 100 mg daily. Both drugs lowered systolic and diastolic blood pressure significantly. After 12 weeks of therapy, supine blood pressure in the tiapamil group fell from 167/104 mmHg to 154/91 mmHg (p less than 0.005), and in the atenolol group from 166/102 mmHg to 151/89 mmHg (p less than 0.005). A satisfactory reduction in diastolic blood pressure, defined as a reduction of more than 10 mmHg and/or values below or equal to 90 mmHg at the end of the study, was achieved in 29 of 35 patients in the tiapamil group and in 27 of 37 in the atenolol group. No changes in heart rate were observed in the tiapamil group, whereas there was a significant fall in heart rate in the atenolol group. The maximal exercise workload tolerated increased equally in both groups, from 135 to 147 watts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1989

Effect of intravenous 1-alpha-hydroxyvitamin D3 on secondary hyperparathyroidism in chronic uremic patients on maintenance hemodialysis.

The effect of intravenous 1 alpha(OH)D3 on circulating intact parathyroid hormone (PTH) and COOH-terminal immunoreactive PTH was examined in 21 patients on chronic hemodialysis. The patients were treated for 3 months with increasing doses of 1 alpha(OH)D3 under careful control of serum Ca2+. 1 alpha(OH)D3 was given intravenously at doses of up to 4 micrograms three times a week, and blood samples were obtained every week, including 1 week before treatment (basal control). No patients were treated with oral vitamin D metabolites. At the end of the study intact PTH levels were reduced by an average of 67 +/- 6%, and COOH-terminal immunoreactive PTH levels were reduced by 35 +/- 6%. Serum Ca2+ was kept within normal levels, but showed a slight increase from 1.17 to 1.30 mmol/l. An effect of calcium on PTH secretion could not be excluded, but an effect of 1 alpha(OH)D3, independent of serum Ca2+ was also found. This effect may be mediated by 1,25(OH)2D3, assuming a large capacity of the 25-hydroxylase in the liver to convert 1 alpha(OH)D3 to 1,25(OH)2D3. Also, the parathyroid glands may possess receptors for 1 alpha(OH)D3 with an effect similar to that established for the 1,25(OH)2D3 receptors. Thus, although the exact mechanisms of the action of 1 alpha(OH)D3 have not yet been completely clarified, it is concluded that intravenous administration of 1 alpha(OH)D3 may be of benefit in the treatment of secondary hyperparathyroidism of uremia.

Adolescent↗
PubMed1988

[Doxazocin].

Explore the source record for details and available documents.

Animals↗
PubMed1988

Serum vitamin D metabolites and nuclear uptake of (3H)-1,25-dihydroxyvitamin D3 in monocytes from patients with autosomal dominant osteopetrosis: a study of two radiological types.

The nuclear uptake of (3H)-1,25 dihydroxyvitamin D3 in freshly isolated human monocytes and the serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were investigated in 13 patients with autosomal dominant osteopetrosis and in sex- and age-matched controls. Seven patients had type I osteopetrosis characterized by diffuse, symmetrical osteosclerosis with pronounced sclerosis of the skull and increased thickness of the cranial vault. The other six patients had type II with "Rugger Jersey Spine" and "endobones" as characteristic findings. In type I osteopetrosis the serum 1,25-dihydroxyvitamin D was significantly reduced (p less than 0.05), whereas serum 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D receptor binding were normal. In type II osteopetrosis the serum vitamin D metabolites were normal, as was the maximal binding capacity (Bmax) of 1,25-dihydroxyvitamin D to the nuclear receptor. The dissociation constant (Kd), however, was significantly increased (p less than 0.01) indicating a modest resistance to 1,25-dihydroxyvitamin D. It is concluded that a general end-organ resistance to 1,25-dihydroxyvitamin D at the receptor level does not exist in type I osteopetrosis, but may contribute to some of the radiological and biochemical findings in type II.

Adult↗
PubMed1988

The effects of short-term, high-dose treatment with prednisone on the nuclear uptake of 1,25-dihydroxyvitamin D3 in monocytes from normal human subjects.

Animal and cell culture studies indicate glucocorticoid regulation of 1,25-dihydroxyvitamin D3 receptors and interference with cellular effects of vitamin D. These investigations prompted us to examine the effects of prednisone on the nuclear uptake of 1,25-dihydroxyvitamin D3 in freshly isolated human monocytes. Eighteen normal subjects were studied in a randomized, double-blind, placebo-controlled study. Analysis of receptor kinetics revealed that the maximal nuclear uptake (Bmax) of (3H)-1,25-dihydroxyvitamin D3 in monocytes decreased 40% (P less than .001) after prednisone treatment. In the group treated with prednisone (40 mg/d for 5 days) s-1,25-dihydroxyvitamin D increased 46% (P less than .01). S-25-Hydroxyvitamin D, S-phosphat, S-calcium, and S-iPTH remained unchanged. Osteoblastic production of the matrix protein, bone gla protein (BGP) is stimulated by 1,25-dihydroxyvitamin D3. However, despite increased serum levels of 1,25-dihydroxyvitamin D3, the prednisone-treated group revealed a 75% reduction in s-BGP. The present data indicate that corticosteroids decrease the nuclear uptake of 1,25-dihydroxyvitamin D3 in human monocytes. Further investigations are necessary, however, to elucidate the biologic mechanism for this observation and whether the mechanism is operative in other human tissues including bone.

Adult↗
PubMed1988

Atrial natriuretic peptide during exercise in patients with coronary heart disease before and after single dose atenolol and acebutolol.

Plasma atrial natriuretic peptide (ANP) was measured during dynamic exercise in 10 patients with coronary heart disease before and after single dose atenolol 50 mg and acebutolol 200 mg, respectively. Systolic blood pressure, heart rate and the rate-pressure product increased during exercise before and after beta-blockade, but levels were lower after beta-blockade. Plasma ANP levels at rest were unchanged after atenolol, but rose after acebutolol (p less than 0.01). During exercise plasma ANP increased significantly both before and after beta-blockade, but plasma ANP levels were higher after acebutolol at all workloads (p less than 0.05), whereas plasma ANP levels after atenolol were higher at 125 W exclusively (p less than 0.05). The augmented ANP levels during exercise after beta-blockade probably reflect catecholamine-stimulated ANP release, whereas the elevated plasma ANP levels after acebutolol at rest might be a beta-adrenoceptor-mediated ANP release due to the intrinsic sympathomimetic effect of acebutolol.

Acebutolol↗
PubMed1988

Changes in atrial natriuretic factor during preload reduction with nitroglycerin in patients with congestive heart failure.

Nine patients with congestive heart failure, New York Heart Association class II-III, were evaluated with right heart catheterization. Plasma atrial natriuretic factor (ANF) was determined in blood samples from the pulmonary artery simultaneously with recordings of right atrial, pulmonary arterial, pulmonary capillary wedge and systemic arterial pressures and heart rate during preload reduction with 0.5 mg nitroglycerin sublingually. Basal plasma ANF levels were higher in patients with congestive heart failure compared to normal controls, and correlated to right atrial, pulmonary arterial, and pulmonary capillary wedge pressures. After nitroglycerin all patients had reductions in right atrial, pulmonary arterial, and pulmonary capillary wedge pressures and a simultaneous decrease in plasma ANF concentrations, reaching lowest values after 10 min. Central pressures and plasma ANF rose to baseline values within 30 min. After nitroglycerin plasma ANF concentrations correlated to pulmonary arterial and pulmonary capillary wedge pressures, while changes in plasma ANF correlated to changes in right atrial and pulmonary arterial pressures. These results provide further evidence that ANF is released by a pressure-sensitive mechanism and demonstrates that ANF secretion in relation to central pressure variations is preserved in patients with congestive heart failure and that the response is rapid.

Adult↗
PubMed1988

Atrial natriuretic factor during exercise in patients with congestive heart failure.

In order to evaluate the potential relationship between atrial pressure development and release of atrial natriuretic factor (ANF), 33 patients with congestive heart failure were investigated with right-sided heart catheterization during supine graded bicycle exercise. Resting plasma ANF levels were higher in patients with heart failure as compared with normal controls, 75.1 +/- 45.6 pmol/l vs 12.3 +/- 6.2 pmol/l (mean +/- SD, N = 33 and N = 42, respectively) and correlated with right atrial, pulmonary arterial and pulmonary capillary wedge pressures. During exercise, central pressures rose steeply with a simultaneous increase in plasma ANF in all patients. Plasma ANF levels correlated with heart rate at a workload of 25 w, to pulmonary arterial and pulmonary capillary wedge pressure at 50 w, and to pulmonary capillary wedge pressure at 75 w. The increments in ANF levels between the different workloads during exercise did not correlate with the corresponding increments in pressure values. In congestive heart failure, the capability of ANF secretion in consequence to pressure stimuli is preserved, and left atrial pressure seems to be the major stimulus for ANF release during exercise.

Adult↗
PubMed1988

The effects of high-dose glucocorticoid administration on serum bone gamma carboxyglutamic acid-containing protein, serum alkaline phosphatase and vitamin D metabolites in normal subjects.

The effects of 40 mg of prednisone given daily for 5 days to normal individuals on serum levels of bone Gla-protein (BGP), alkaline phosphatase, calcium phosphate, 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D and immunoreactive parathyroid hormone (S-iPTH) and on renal excretions of calcium, phosphate and hydroxyproline were evaluated in a double-blind, placebo controlled study. In the prednisone group a 75% decrease (P less than 0.001) was found in serum BGP compared to a 6% decrease (P less than 0.05) in serum alkaline phosphatase. The renal hydroxyproline excretion remained unchanged. Serum calcium was unchanged while the fasting urinary calcium excretion showed a 2-fold increase (P less than 0.001). Serum 1,25-dihydroxyvitamin D increased (P less than 0.01) in spite of unchanged serum 25-hydroxyvitamin D, serum phosphate and parathyroid function (as judged by S-iPTH and the maximal tubular reabsorption capacity for phosphate (TmP/GFR]. The data suggest a direct inhibition of osteoblast number and/or function by short-term glucocorticoid administration with unchanged bone resorption leading to a negative bone mineral balance. The increase in serum 1,25-dihydroxyvitamin D is probably due to a direct stimulation by glucocorticoids of the renal 1 alpha-hydroxylase. The effects of the vitamin D metabolite, however seem to be blunted.

Adult↗
PubMed1987

Low serum levels of 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D in institutionalized old people: influence of solar exposure and vitamin D supplementation.

The vitamin D status was investigated in 94 geriatric patients in a Danish long-stay ward. The influence of mobility and thus possibility of outdoor activity was studied as well as the influence of regular vitamin D intake. Serum levels of 25-hydroxyvitamin D (25-OHD) were significantly reduced in all groups compared with age-matched controls. In 50% of the patients hypocalcaemia and elevated levels of alkaline phosphatase and immunoreactive parathyroid hormone (iPTH) were found in combination with severely reduced serum 25-OHD values (less than 5 ng/ml) indicating the presence of osteomalacia. Supplementation with 400 IU vitamin D daily in the winter months resulted in significantly higher 25-OHD levels and normocalcaemia while slightly elevated levels of alkaline phosphatase and iPTH persisted. The serum concentrations of 25-OHD were highest in the subjects who were not confined to bed. In these patients the biochemical parameters reflecting osteomalacia were normal. Low serum 1,25-dihydroxyvitamin D levels were found in the patients with low 25-OHD while 24,25-dihydroxyvitamin D levels were within the normal range in all groups and correlated with 25-OHD. Daily vitamin D supplementation appears to be indicated for geriatric patients, especially when bedridden, even in countries where the nutritional vitamin D intake is high.

Aged↗
PubMed1987

Changes in plasma atrial natriuretic peptide during exercise in healthy volunteers.

Graded exercise was performed in three healthy volunteers. Plasma levels of immunoreactive atrial natriuretic peptide (iANP) were determined at different workloads. Unchanged or slightly decreased plasma levels of iANP were observed during light exercise, whereas at medium to high workloads a considerable increase in plasma levels of iANP was found. Factors responsible for the increase in plasma levels of iANP might include elevated right atrial pressure and increased plasma levels of epinephrine and norepinephrine.

Adult↗
PubMed1987

Effect of beta 1-adrenoceptor blockade on plasma levels of atrial natriuretic peptide during exercise in normal man.

Increased plasma levels of atrial natriuretic peptide (ANP) during exercise have been reported. To investigate the role of tachycardia as a stimulus for release of ANP during exercise the following study was undertaken. Graded exercise was performed in six healthy volunteers before and after beta 1-adrenoceptor blockade. Plasma levels of ANP were determined at different workloads in both cases. At rest and at all workloads during exercise plasma levels of ANP were higher after beta 1-adrenoceptor blockade than without. Therefore, it is unlikely that tachycardia is a major stimulus for secretion of ANP during exercise. It is suggested that increased right atrial pressure and/or pulmonary arterial blood pressure and increased plasma levels of catecholamines are important secretory stimuli for ANP during exercise.

Adrenergic beta-Antagonists↗