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Biomedical subjects

P Rødbro

Publications and source records attributed to P Rødbro.

At least 55 records · Page 3Linked to original sources
PubMed1984

Impairment of vitamin D metabolism and bone mineral content after intestinal bypass for obesity. A longitudinal study.

Ten obese subjects who had undergone intestinal bypass operation (end-to-side jejunoileostomy) were studied longitudinally with respect to vitamin D and other indices of calcium metabolism. Investigations were carried out before operation (t0) and after 6 months (t1), 12 months (t2), and a mean of 54 months (range, 49-58 months) (t3) postoperatively. Serum 25-hydroxyvitamin D (25OHD) was subnormal at t0 but after operation values declined gradually to an extremely low level at t3, possibly because of a loss through malabsorption. Serum 24,25-dihydroxyvitamin D remained normal at t1 and t2 but fell to about half the normal level at t3, probably owing to lack of its precursor, 25OHD. In contrast, serum 1,25-dihydroxyvitamin D (1,25(OH)2D) remained normal throughout the study, indicating a marked stimulation of kidney 1 alpha-hydroxylase activity. Serum calcium fell rapidly to a constant subnormal level, and it is concluded that the serum calcium malabsorption is due to factors other than impaired 1,25(OH)2D activity. Bone mineral content (BMC) was unchanged between t0 and t2, but thereafter (between t2 and t3) the mean BMC fell rapidly to about 90% of preoperative value, possibly due to a defective bone mineralization in the late postoperative period. The findings indicate a high risk of bone disease developing after intestinal bypass operation. Substitution with calcium and vitamin D should be given to these patients, but the optimal vitamin D metabolite (or combination of metabolites) for such treatment is still unknown.

24,25-Dihydroxyvitamin D 3↗
PubMed1983

Anaphylactic reaction to orthoiodohippurate.

A case of an anaphylactic reaction following administration of 125I- and 131I-o-iodohippurate in a 32-year-old woman is reported. The patient had a renography performed because of hematuria. She was known to react to an intravenous pyelography previously performed with an anaphylactic shock. The importance of reporting all adverse reactions to radiopharmaceuticals for central registration is stressed.

Adult↗
PubMed1983

Does postmenopausal bone loss respond to estrogen replacement therapy independent of bone loss rate?

Bone loss in postmenopausal women can be treated by hormonal substitution therapy. We investigated whether rapid bone losers (as opposed to nonrapid losers) respond sufficiently to estrogen treatment. A sample of 88 early postmenopausal women was followed up for a 2-year observation period in which bone mineral content (BMC) was followed up every 3 months. From these data, 20 women were classified as rapid losers (bone loss greater than 3% per year) and 68 women as nonrapid losers. The women were allocated to treatment with estradiol in 4, 2, and 1 mg doses daily and followed up for 1 year. The mean response on BMC was dose-dependent, ranging from +1.6% per year with the 4 mg dose to -0.2% per year with the 1 mg dose. In none of the groups was there any difference in response between rapid and nonrapid losers. It is concluded that the BMC loss during observation in some participants (rapid losers) is considerable and that these participants respond in the same manner as nonrapid losers.

Aged↗
PubMed1983

Vitamin D and bone mineral content after intestinal bypass operation for obesity.

Twenty-three obese subjects who had undergone intestinal bypass operation (end-to-side jejunostomy) were studied with respect to vitamin D and other indices of calcium metabolism. Group 1 (11 patients) was examined before and one year after operation. Group 2 (12 patients, bypass operated two to seven years earlier was investigated twice with an interval of one year. The two groups were comparable. Bone mineral content and alkaline phosphatases were unchanged during the study in both groups. Bone phosphorus/hydroxyproline ratio was high postoperatively indicating a high degree of bone mineralisation. Serum calcium declined rapidly in group 1 to a constant level, which was maintained in group 2. The serum levels of iPTH and 1,25(OH)2D did not change within each group, but combining the two groups demonstrated an increase/decrease in iPTH/1,25(OH)2D over the years. The findings suggest that factors other than 1,25(OH)2D and iPTH are involved in calcium metabolism in such patients. The findings do not justify routine administration to such patients of high potency vitamin D derivatives, f.ex. 1 alpha-OH-D3.

25-Hydroxyvitamin D 2↗
PubMed1983

Pathophysiology behind anticonvulsant osteomalacia.

Anticonvulsant drug-induced disorders in mineral and bone metabolism are discussed. 'Anticonvulsant osteomalacia' includes hypocalcaemia, elevated serum alkaline phosphatase, decreased serum 25-hydroxycholecalciferol (25 OHD3), radiological and histological signs of osteomalacia and a lower bone mineral content (BMC) than normal. The pathophysiological mechanism behind anticonvulsant osteomalacia is thought be an induction of the microsomal enzyme system in the liver, leading to a disturbance in the metabolism of vitamin D and a resulting vitamin D deficiency. It has been shown that treatment with vitamin D2 increase BMC whereas serum calcium was unchanged. Treatment with vitamin D3 or 25 OHD3 increases serum calcium whereas BMC was unchanged. These findings suggest that vitamin D2 and D3 are metabolized differently in anticonvulsant treated patients. With the present knowledge, preventive treatment of this relative mild pathological condition is not generally indicated.

Alkaline Phosphatase↗
PubMed1983

Bone mineral content in patients on prolonged maintenance hemodialysis: a three year follow-up study.

Bone mineral content (BMC) was measured annually over a three year period in 31 consecutive patients on maintenance hemodialysis (HD). No patient had received treatment with vitamin D derivatives, anticonvulsants or corticosteroids, nephrectomy or a renal transplant. Initial median BMC value in per cent of sex and age matched normal mean was significantly decreased to 91.0% (P less than 0.01), indicating bone mineral loss in chronic renal failure prior to HD. During HD a highly significant fall in mean BMC (in per cent of initial value) continued to 95.1%, 92,7% and 90.8% after 1, 2 and 3 years, respectively, with no influence of age, sex or initial BMC value. The interindividual variation in BMC changes, however, was considerable: the BMC loss over 3 years exceeded 10% in 13 (42%) patients ("rapid losers") while 12 (39%) patients had a BMC loss below 5%, or no loss at all. The "rapid loser" group had significantly higher serum levels of parathyroid hormone and alkaline phosphatases and, moreover, developed a lower serum phosphate and calciumXphosphorus product than the other group of patients ("slow losers"). The mean BMC loss over 3 years of HD was pronounced and significant (P less than 0.02) in patients with chronic pyelonephritis (9.8%) and polycystic kidney disease (14.2%), but much smaller, and not significant, in patients with chronic glomerulonephritis (4.8%). It is concluded that a selection of patients with a high degree of bone mineral loss during HD is not possible by means of sex, age, initial BMC, biochemical parameters, or diagnosis (2 patients with chronic glomerulonephritis appeared to be "rapid losers"). For that purpose a high-precision BMC method is mandatory.

Adult↗
PubMed1982

Variable interpretation of liver scintigraphy in malignancy as an aid in clinical decision-making.

Despite technical progress in liver radioisotope scintigraphy, the overall accuracy in detecting metastases has not improved. It has been suggested that a fixed scintigram interpretation in reply to changing clinical problems is partly responsible. An evaluation of the possibilities of improving the clinical value of the test by using six cutoff levels in the scintigraphic interpretation is presented. The test population is a prospectively planned consecutive series of 185 patients strongly suspected of having gastric or colo-rectal malignancies. The incidence of liver metastases was 15%. The relationship between the predictive value of a positive test and the false negative ratio at different incidences of metastases is demonstrated graphically. To improve the clinical value of liver scintigraphy, a close cooperation between clinicians and physicians in nuclear medicine to define the clinical problem and the appropriate scintigraphic cutoff level is necessary.

Colonic Neoplasms↗
PubMed1982

Corticosteroid-induced osteopenia and vitamin D metabolism. Effect of vitamin D2, calcium phosphate and sodium fluoride administration.

Thirty-one patients scheduled for long-term (24 weeks) treatment with prednisone in comparatively high doses were randomly allocated to two further treatment groups. Group A received prednisone plus 'triple-treatment' (vitamin D2 45000 iu twice weekly, sodium fluoride 50 mg and calcium phosphate 4.5 g daily), group B received only prednisone. The study was undertaken in order to evaluate the effect of prednisone- and triple-treatment upon bone mineral content (BMC) and vitamin D metabolism. The groups were comparable with regard to age, sex and prednisone dose. BMC fell rapidly and similarly in both groups, demonstrating that the triple-treatment has no preventive effect on corticosteroid induced osteopenia. Serum concentrations of 25OHD2, 25OHD3 and 1,25(OH)2D were unchanged in group B (without triple-treatment), whereas in group A 25OHD2 increased enormously, 25OHD3 was suppressed possibly by substrate competition for hydroxylation in the liver and 1,25(OH)2D was halved. The suppression of 1,25(OH)2D may be an effect of raised 25OHD2 alone, or in combination with corticosteroid excess.

Alkaline Phosphatase↗
PubMed1982

Assessment of ileal function by abdominal counting of the retention of a gamma emitting bile acid analogue.

In eight patients without gastrointestinal complaints and 30 patients with various gastrointestinal disorders ileal bile acid conservation was assessed by oral administration of 75Se 23-selena-25-homocholic acid (SeHCAT) followed by abdominal gamma counting (SeHCAT-test). The results of the test correlated fairly well with the clinical features and with the [1-14C]-cholylglycine breath test including faecal 14C measurements (breath test). Of the two bile acid absorption tests the new is perhaps the more sensitive and is the one most easily performed.

Adult↗
PubMed1981

Bone mineral content before and after intestinal bypass operation in obese patients.

With the aim of investigating bone mineral loss after intestinal bypass operation, bone mineral content (BMC) was measured by two-dimensional scanning photon absorptiometry on the distal part of the forearm in 23 consecutive patients who had undergone intestinal bypass operation for obesity. Eleven patients (group 1) were investigated before and 12 months after operation, and 12 (group 2), who had been operated on 2-7 years earlier, were investigated two times at an interval of 12 months. No patient received therapeutic calcium or vitamin D supply. The predominant biochemical findings postoperatively were decreased serum values of calcium, magnesium, albumin, and total protein; there was no change in inorganic phosphate or alkaline phosphatase. Mean BMC was normal in both groups postoperatively as well as in group 1 before operation; there was no significant change in mean BMC during 12 months of observation. However, in BMC measurements on extremely obese subjects, a correction for the excessive fat layer on the forearm was necessary because of different attenuation properties of fat and soft tissues. Neglect of this problem will give a systematic underestimation of BMC, and may lead to false conclusions in cross-sectional as well as longitudinal studies.

Adult↗
PubMed1981

Is 1,25-dihydroxy-cholecalciferol harmful to renal function in patients with chronic renal failure?

Seventeen undialysed adult patients with chronic renal failure took part in a controlled study of the effects of 1,25(OH)2D3 and D3. After a 6-month observation period the patients were allocated at random to two groups for 6 months of treatment with either 1,25(OH)2D3 (mean dose 0.5 microgram daily) or D3 (dose 100 microgram daily). Treatment was then discontinued and the patients were studied for a further 6 months. Serum iPTH was decreased in both groups but most markedly in the 1,25(OH)2D3 group in which the iPTH values became normal. Serum creatinine increased during treatment in both groups. In the group receiving 1,25(OH)2D3 this was coupled to an increase in serum calcium within the normal range. Our data demonstrate that 1,25(OH)2D3 treatment in patients with chronic renal failure leads to a further reduction in renal function, which may be partially reversible. Physicians should therefore be reluctant to give vitamin D analogues to patients with chronic renal failure unless they have severe symptomatic renal osteodystrophy.

Adult↗
PubMed1981

A possible direct effect of 24,25-dihydroxycholecalciferol on the parathyroid gland in patients with chronic renal failure.

Seventeen undialysed adult patients with chronic renal failure took part in a controlled study of the effects of 1,25(OH)2D3 and D3. After a 6-month observation period the patients were allocated at random to two groups for 6 months of treatment with either 1,25(OH)2D3 (mean dose 0.5 microgram daily) or D3 (dose 100 microgram daily). The treatment was then discontinued and the patients were studied for a further 3 months. In the 1,25(OH)2D3 group the mean serum concentration of 1,25(OH)2D rose significantly during treatment, whereas serum concentratins of 25OHD and 24,25(OH)2D remained unchanged. In the D3 group there was a highly significant increase in serum concentrations of 25OHD and 24,25(OH)2D, whereas serum 1,25(OH)2D remained unchanged. There was a significant fall in serum iPTH in both treatment groups. This fall was unrelated to serum calcium in the D3 group unlike the findings in the 1,25(OH)2D3 group. The data support previous experimental evidence that serum iPTH can be suppressed by 24,25(OH)2D3 and suggest that this analogue may be of clinical importance in the treatment of chronic renal failure without inducing hypercalcaemia.

24,25-Dihydroxyvitamin D 3↗
PubMed1981

Effect of 1,25-dihydroxy-vitamin D3 in itself or combined with hormone treatment in preventing postmenopausal osteoporosis.

Eighty-four normal women, 2.5--5 years after their natural menopause, participated in a controlled double-blind trial. The effect of various therapeutic regimens on postmenopausal bone mineral loss was measured by photonabsorptiometric determination of the bone mineral content of both forearms. The women were randomized into four treatment groups: 1,25-dihydroxycholecalciferol (1,25(OH)2D3) alone in a daily dose of 0.25 micrograms, oestrogens/gestagen alone or combined with 1,25(OH)2D3, and placebo. The groups treated with oestrogens/gestagen (without and with 1,25(OH)2D3) showed a similar increase in bone mineral content of about 1% during one year of treatment. In contrast, both the placebo group and the 1,25(OH)2D3 group demonstrated a decrease of 1.9% and 2.1%, respectively, within the same period of time. While 1,25(OH)2D3 did not alter the rate of bone loss, it caused the characteristic and pronounced increase in urinary calcium excretion (15%). It is concluded that 1,25 (OH)2D3 neither serves as an alternative nor as an additive to gonadal hormones in the prevention of postmenopausal osteoporosis.

Bone and Bones↗
PubMed1981

Elevated glomerular filtration rate in early diabetes may be explained by increased sodium reabsorption secondary to an impairment in renal tubular handling of phosphate.

Glomerular filtration rate, the renal threshold concentration for phosphate and the tubular reabsorption rates of glucose, phosphate and sodium were determined in the fasting state of 26 diabetic children without clinical signs of microangiography and in 28 healthy school children. The renal threshold concentration for phosphate was significantly decreased in the juvenile diabetics (p less thn 0.001) and was negatively correlated to the rate of glucose (r = 0.59, p less than 0.01). The tubular sodium reabsorption was markedly increased as compared to the healthy children (p less than 0.001) and for all children the threshold concentration for phosphate was negatively correlated to the tubular sodium reabsorption (p less than 0.001). In the diabetic children the tubular sodium reabsorption was closely correlated to the absolute phosphate reabsorption (p less than 0.001) and to GFR (p less than 0.0001). Therefore, in spite of the defective renal threshold for phosphate induced by the increased glucose reabsorption, the absolute phosphate reabsorption became normalized in the juvenile diabetics by an increase in sodium reabsorption and thus by an increase in GFR.

Blood Glucose↗
PubMed1981

Mineral metabolism in chronic renal failure with special reference to serum concentrations of 1.25(OH)2D and 24.25(OH)2D.

This study examines the interrelationship between serum levels of substances important in mineral metabolism including the 3 vitamin D metabolites 25OHD, 24.25(OH)2D and 1.25(OH)2D and static and dynamic histomorphometric measurements of bone remodelling in iliac crest biopsies in 17 patients with chronic renal failure. No correlation was found between the serum values of any of the vitamin D metabolites and the histomorphometric values. However, significant inverse correlations were found between serum calcium and both the osteoid surface extent (P less than 0.05) and osteoid volume (P less than 0.05) in trabecular bone. Serum immunoreactive parathyroid hormone (iPTH) was positively related to trabecular osteoclastic bone resorption. The serum level of 1.25(OH)2D was inversely related to endogenous creatinine clearance (P less than 0.01). These results support the hypothesis that the serum calcium concentration is more important than the serum concentration of vitamin D metabolites for bone remodelling in chronic renal failure.

Bone and Bones↗
PubMed1980

Pubertal growth as reflected by simultaneous changes in bone mineral content and serum alkaline phosphatase.

Bone mineral content and total serum alkaline phosphatase were measured simultaneously in 230 normal children and adolescents aged 7-20 years. The bone mineral content showed almost no variation from the age of 7 to 13 in boys a,d 7 to 11 in girls. Thereafter a sharp increase was seen in both sexes with a highly significant sex difference between the mean values. Bone mineral content showed a fairly high correlation with age, height, weight, and surface area in boys. Before the time of the growth spurt, however, these variables were poorly correlated or not correlated at all. Concentrations of total serum alkaline phosphatase increased up to the age of 14 in boys and 11 in girls. Thereafter a rapid fall was seen in both sexes, the mean levels being significantly higher in boys. The fall approximated adult levels in boys by the age of 20 and in girls by 18. A significant negative correlation between bone mineral content and serum alkaline phosphatase was seen both in boys (r=0.71, p less than 0.001) and in girls (r=0.79, p less than 0.001).

Adolescent↗