[Calcinosis universalis with hyperphosphataemia--successful treatment with phosphorus deprivation]

Seven year old boy with calcinosis universalis associated with high serum phosphorus was reported. Over one year's treatment with aluminum hydroxide up to 18 grams per day have reduced calcified mass remarkably, while serum phosphorus levels were remaining still above the normal range. Concomitant use of probenecid seemed to be effective in reducing serum phosphorus levels as well as decreasing the calcified mass. Pathogenetic mechanisms of soft tissue calcification in calcinosis universalis is not clear, but in this case hyperphosphataemia is considered to be one important factor accelerating soft tissue calcification. Although hyperphosphataemia associated with tumoral calcinosis has been frequently observed, no report is yet available on calcinosis universalis associated with hyperphosphataemia. This case might represent one unique type of calcinosis.

Biological characteristics for assessing low phosphorus intake in growing swine

A total of 195 swine from 18 to 35 kg were used to evaluate various biological responses of growing swine fed low P diets at different Ca:P ratios. Three replicates of a randomized complete-block design in a 3 X 3 factorial arrangement of treatments were used. Total dietary P levels of .12, .31 and .50% were fed in 1:1, 1.5:1 or 3:1 Ca:P ratios. Diets were formulated using corn starch, dextrin and soy protein concentrate, with monosodium phosphate and limestone used to supply appropriate dietary treatment levels of Ca and P. Gain and feed performance were generally influenced by both Ca:P ratio and dietary P level. Serum inorganic P decreased linearly as Ca:P ratio widened and increased linearly as dietary P increased. Serum Ca concentrations responded inversely to serum inorganic P in response to both Ca:P ratio and dietary P level. Serum alkaline phosphatase was not affected by Ca:P ratio, but declined quadratically with increasing dietary P level. Bone bending moment was influenced by both dietary P level and Ca:P ratio. Bone component weights (ash, organic matrix), percentage bone ash and net accretion of bone ash and organic component weights were not influenced by Ca:P ratio but increased linearly as dietary P level increased. These results suggest that bone component weights, net ash accretion and percentage bone ash were more sensitive criteria than bone bending moment or serum alkaline phosphatase, which in turn were more sensitive than serum inorganic P, Ca, Mg and growth performance characteristics in response to dietary P level.

Sequential changes in red cell glycolytic enzymes and intermediates and possible control mechanisms in the first two months of postnatal life in lambs

The sequential changes in several glycolytic enzymes, glucose-6-phosphate dehydrogenase, glycolytic intermediates, and adenosine triphosphate, as well as intracellular pH and plasma inorganic phosphorus were followed simultaneously in eight lambs from birth to 2 months of age. The activities of all glycolytic enzymes and glucose-6-phosphate dehydrogenase were elevated at birth. The 2,3-diphosphoglycerate concentration increased markedly postnatally and was associated with a simultaneous increase in the concentrations of red cell glucose-6-phosphate and total triose phosphate and a decrease in intracellular pH. Inorganic phosphorus also increased and correlated with the 2,3-diphosphoglycerate concentration in the first 10 days of postnatal life. The content of red cell 3-phosphoglycerate, 2-phosphoglycerate, phosphoenolpyruvate, and ATP increased slightly. These results suggested increased glycolytic flux through the diphosphoglycerate mutase reaction which resulted in net synthesis of 2,3-diphosphoglycerate. The red cell total triose phosphate peaked and fell initially, followed by glucose-6-phosphate and 2,3-diphosphoglycerate suggesting inhibition of phosphofructokinase activity and a decrease in glycolysis secondary to decreased red cell intracellular pH. After 10 days of postnatal life all glycolytic intermediates fell simultaneously, which correlated with a decrease in activity of the glycolytic enzymes.

Phosphorus labeling of proteins and phospholipids in intact platelets in response to pH 5.3

Previous studies had shown that when gel-filtered or washed human platelets were incubated at pH 5.3, the cells secreted their granule-stored materials suggesting that low pH can act as a platelet activator. We determined here whether the effects of low pH on platelet protein phosphorylation and on platelet lipid metabolism were consistent with this view. When washed human platelets were incubated for 20 min at pH 5.3 and electrophoresed on SDS-PAGE, there was a great increase in 32P-label in the 20,000 and 47,000 dalton protein bands. There was also an increase in the labeling of phosphatidic acid and a small decrease in phosphatidyl inositol. When the platelets were returned to pH 7.6, the 32P labeling of the 20,000 and 47,000 dalton bands was greatly reduced, and that of phosphatidic acid reduced to the control value, while the labeling of phosphatidyl inositol was increased above control. Incubation at pH 5.3 for 60 min gave the same pattern, but return to pH 7.6 resulted in only partial reversal of labeling of the two protein bands and little decrease in the label associated with phosphatidic acid, but the radioactivity in phosphatidyl inositol was greatly increased. The changes in the 32P-labeling of phospholipids and proteins after incubation of platelets at pH 5.3 may reflect an increase in cytoplasmic Ca++ resulting from leakage of Ca++ from intracellular storage sites, a process which becomes irreversible after longer time exposure to the low pH.(ABSTRACT TRUNCATED AT 250 WORDS)

Serum levels of 1,25-dihydroxyvitamin D in children receiving parenteral nutrition with reduced aluminum content

Both adults and children receiving total parenteral nutrition (TPN) have been found to have low serum levels of 1,25(OH)2-vitamin D [1,25(OH)2D]. Many of these were subsequently found to have inadvertently received large quantities of aluminum in the TPN solution. Since aluminum administration to dogs is associated with a fall in serum 1,25(OH)2D levels, the present study was designed to prospectively follow serum levels of this sterol while patients received a TPN solution low in aluminum. Nine children received a TPN solution comparable to that previously administered to children who demonstrated low serum levels of 1,25(OH)2D, except for a moderately reduced phosphorus and markedly reduced aluminum content. Serum was obtained during the first and fourth weeks of TPN treatment and analyzed for 1,25(OH)2D, 25-hydroxyvitamin D [25(OH)D], immunoreactive parathyroid hormone (iPTH), calcium, and phosphorus. Results revealed normal or high serum levels of 1,25(OH)2D and normal levels of iPTH, calcium, phosphorus, and 25(OH)D. Thus, low aluminum-containing TPN does not produce a fall in serum 1,25(OH)2D, providing evidence that aluminum may have been a factor in causing the reduced serum 1,25(OH)2D in those children previously receiving TPN.

Regulation of bone mineral loss during lactation

The effects of varying dietary calcium and phosphorus content, vitamin D deficiency, oophorectomy, adrenalectomy, and simultaneous pregnancy on bone mineral loss during lactation were examined in rats. Unless otherwise stated, the diet contained 0.47% calcium and 0.3% phosphorus and the rats were given 26 nmol of vitamin D3. Femur ash weights were determined after 21 days of lactation and on age-matched nonlactating rats. Decreasing dietary calcium to 0.02% caused an increased loss of bone mineral, whereas increasing dietary calcium to 1.4% increased plasma calcium levels to 12 mg/100 ml but did not diminish the bone mineral loss observed during lactation. Varying dietary phosphorus did not have a major effect on bone mineral loss during lactation. In vitamin D-deficient rats, bone mineral loss during lactation was independent of dietary calcium levels and slightly greater than the loss observed in vitamin D-replete rats fed the normal calcium diet. Oophorectomy and adrenalectomy did not produce changes in femur ash weights of nonlactating rats or reduce bone mineral loss during lactation. Rats mated during their postpartum estrus and thus simultaneously pregnant and lactating, lost the same amount of bone mineral as caused by lactation alone.

The negative correlation between prolactin and ionic calcium in cord blood of full term infants

Total serum calcium (Ca), ionic calcium (Ca++), phosphorus, magnesium, total protein, immunoreactive parathyroid hormone (iPTH), calcitonin (iCT) and prolactin (iPRL) were measured in 30 paired samples of cord and maternal blood obtained at term delivery. In the cord blood, the concentrations of Ca, Ca++, phosphorus, magnesium, albumin, iCT and iPRL were all higher, and the concentrations of total protein and iPTH lower than in the maternal blood. The calcium binding capacity of albumin assessed with the equation (Ca-Ca++)/albumin, was similar at a given concentration of Ca in both the maternal and fetal circulations. There was a significant positive correlation between cord Ca++ and maternal Ca or Ca++, and a significant negative correlation between Ca++ and iPRL in cord blood. These data suggest that there is an active system transporting calcium from mother to fetus through the placenta, and PRL is the only one of the three hormones which was correlated with ionic calcium values in the fetus. The negative relationship between Ca++ and iPRL in the cord blood suggests an inhibitory effect of the relative hypercalcemia on PRL secretion in the fetus.

Osmotic fragility of erythrocytes, cell deformability and secondary hyperparathyroidism in uremic patients on maintenance hemodialysis

The possible relationship between erythrocyte (RBC) function and secondary hyperparathyroidism (HPT) was examined in 35 uremic patients on maintenance hemodialysis. Mechanical tests (i.e., osmotic fragility and deformability) were used to assess RBC function. Secondary HPT was evaluated by means of serum biochemistry (parathyroid hormone, calcium, phosphorus, and alkaline phosphatase) and radiographic examinations (X-ray films of the hand skeleton). Sixteen sex and age-matched normal volunteers acted as controls. This study shows that the mechanical properties of RBC were indeed markedly altered in hemodialysis patients when compared with controls. No significant correlations between either the osmotic fragility or the deformability of RBC and the hematochemical changes associated with secondary HPT were found. No differences in RBC function tests were found as far as the activity (alkaline phosphatase) or the severity (X-ray findings) of secondary HPT are concerned. Effective treatment of secondary HPT by either pharmacological means (1,25-dihydroxycholecalciferol) or surgical removal was not associated with consequent improvement in RBC function. These findings clearly speak against secondary HPT as a major cause of RBC dysfunction in uremic patients on maintenance hemodialysis.

[Metabolic and renal changes in lymphoproliferative syndromes of childhood]

Authors report five patients with lymphoproliferative diseases who suffered from metabolic and renal disorders hyperuricemia, hyperphosforemia, hyperkaliemia, hypocalcemia and azotemia) during initial phase of chemotherapy. They comment on measures to prevent these disorders and the need of hemodialysis in some cases.

Coexistence of hypocalciuric hypercalcaemia and interstitial lung disease in a family: a cross-sectional study

In a prospective investigation, a large kindred (twenty-one subjects) with unexplained association of familial hypocalciuric hypercalcaemia and idiopathic interstitial lung disease was studied. Serum calcium was increased in fifteen patients (the youngest being 7 years old) and was associated with hypo- or normocalciuria. The abnormalities were not age-dependent. The serum concentrations of parathyroid hormone, 25-hydroxyvitamin D3, 1,25-dihydroxyvitamin D3 and calcitonin were normal. In twelve patients the diffusing capacity (DLCO) and/or DLCO per unit lung volume was less than 75% predicted. This was often accompanied by a vital capacity of less than 80% predicted, and increased Tiffeneau index, and a reticulo-micronodular pattern with high diaphragm on chest X-ray. The decrease in DLCO was more pronounced in older non-smoking as well as smoking subjects (P less than 0.02) suggesting a progressing interstitial disease with age. The fibrosing alveolitis, which had been confirmed by open lung biopsy in three subjects, could not be attributed to sarcoidosis, collagen-vascular disease, or exogenous causes. The disturbances in the calcium homeostasis and in the diffusing capacity of the lung coexisted in seven of the twenty-one patients. Apparently, both abnormalities were inherited following an autosomal-dominant pattern but with a different penetration in each person, and seemed not be causally related to each other.

Effects of insulin on altered mineral and vitamin D metabolism in streptozotocin-induced diabetes

In order to ascertain whether or not abnormal mineral and vitamin D metabolism in diabetes can be reversed by insulin therapy, plasma calcium, ionized calcium, phosphorus, parathyroid hormone (PTH) and vitamin D metabolites were measured in control, streptozotocin (STZ) diabetic and insulin-treated diabetic rats. Blood glucose levels in diabetic rats treated with insulin decreased to normal. The low plasma calcium and ionized calcium levels in diabetic rats were found to be normal in insulin-treated diabetic rats. An elevated PTH level was observed in the diabetic group, but it was at normal levels in the insulin-treated diabetic group. Plasma 25-hydroxyvitamin D (25(OH)D) and 24,25-dihydroxyvitamin D (24,25(OH)2D) in the diabetic group were decreased compared to those in control rats, but these were also fully restored to control levels by insulin therapy. However, plasma 1,25-dihydroxyvitamin D (1,25(OH)2D) levels in the untreated diabetic group tended to be lower than in controls, and the values in insulin-treated rats were significantly decreased compared to the control group. The ratio of 1,25(OH)2D to 25(OH)D in diabetic rats was higher than in controls, but it was decreased after insulin therapy and was significantly lower than in the control group. It is suggested, therefore, that the negative calcium balance and decreased 25(OH)D and 24,25(OH)2D levels are derived from the metabolic derangement due to the insulin deficiency. Furthermore, insulin seems to suppress the conversion of 25(OH)D to 1,25(OH)2D in experimental diabetes in vivo.

Pharmacokinetics and biologic effects of calcitriol in normal humans

The dose response and pharmacokinetics of orally administered calcitriol were investigated in normal humans. In one protocol, six volunteers received calcitriol 0.25 micrograms twice a day, 0.5 micrograms daily, and 0.5 micrograms twice a day, in successive weeks. Peak plasma levels of 1,25(OH)2D occurred 4 to 8 hours after ingestion of a single dose of 0.5 micrograms, with a return to baseline within 24 hours. The 8:00 AM calcitriol plasma levels were raised only when the drug was given twice daily. Urinary calcium excretion (UCa) was significantly increased from 199 +/- 19 mg/24 hr during the control period to similar levels of 302 +/- 26 mg/24 hr after 0.25 microgram twice a day and 284 +/- 31 mg/24 hr after 0.50 microgram daily. With 0.50 microgram twice a day, UCa was 417 +/- 36 mg/24 hr, a value greater than after the lower doses (p less than 0.05). In another protocol, fourteen volunteers received calcitriol 0.25 microgram, 0.5 microgram, and 1.0 microgram twice a day each for 14 days with intervening control periods of 2 weeks. A dose-related response in urinary calcium/creatinine excretion occurred. Thus, UCa (milligrams calcium per milligram creatinine) increased with calcitriol from 0.13 +/- 0.014 mg to 0.15 +/- 0.018 mg with 0.25 microgram twice a day, from 0.13 +/- 0.010 mg to 0.22 +/- 0.022 mg with 0.5 microgram twice a day, and from 0.12 +/- 0.012 mg to 0.23 +/- 0.012 mg with 1 microgram twice a day (p less than 0.05 with 0.25 microgram, p less than 0.01 with 0.5 and 1 microgram twice a day).(ABSTRACT TRUNCATED AT 250 WORDS)

Marked suppression of secondary hyperparathyroidism by intravenous administration of 1,25-dihydroxy-cholecalciferol in uremic patients

Current evidence suggests that administration of 1,25(OH)2D3 to patients with chronic renal insufficiency results in suppression of secondary hyperparathyroidism only if hypercalcemia occurs. However, since the parathyroid glands possess specific receptors for 1,25(OH)2D3 and a calcium binding protein, there is considerable interest in a possible direct effect of 1,25(OH)2D3 on parathyroid hormone (PTH) secretion independent of changes in serum calcium. Recent findings indicate substantial degradation of 1,25(OH)2D3 in the intestine, therefore, it is possible that while oral administration of the vitamin D metabolite increases intestinal calcium absorption, the delivery of 1,25(OH)2D3 to peripheral target organs may be limited. We therefore compared the effects of orally or intravenously administered 1,25(OH)2D3 on the plasma levels of 1,25(OH)2D3 and the effects of these two modes of treatment on PTH secretion. Whereas oral administration of 1,25(OH)2D3 in doses adequate to maintain serum calcium at the upper limits of normal did not alter PTH levels, a marked suppression (70.1 +/- 3.2%) of PTH levels was seen in all 20 patients given intravenous 1,25(OH)2D3. Temporal studies suggested a 20.1 +/- 5.2% decrease in PTH without a significant change in serum calcium with intravenous 1,25(OH)2D3. In five patients the serum calcium was increased by the oral administration of calcium carbonate, the decrement in serum i-PTH was only 25 +/- 6.65% when compared with 73.5 +/- 5.08% (P less than 0.001) obtained by the administration of intravenous 1,25(OH)2D3. Thus, a similar serum calcium achieved by intravenous 1,25(OH)2D3 rather than calcium carbonate has a greater suppressive effect in the release of PTH. These studies indicate that 1,25(OH)2D3 administered intravenously rather than orally may result in a greater delivery of the vitamin D metabolite to peripheral target tissues other than the intestine and allow a greater expression of biological effects of 1,25(OH)2D3 in peripheral tissues. The use of intravenous 1,25(OH)2D3 thus provides a simple and extremely effective way to suppress secondary hyperparathyroidism in dialysis patients.

Vitamin D replacement therapy and renal function. Calcitriol v dihydrotachysterol

We treated 24 patients who had chronic renal insufficiency and renal osteodystrophy with either calcitriol (1,25-dihydroxyvitamin D3) or dihydrotachysterol. Renal function was evaluated before and during treatment to determine if these vitamin D analogues caused an accelerated rate of renal function deterioration. An accelerated rate of increase in the serum creatinine level was found in three of 12 patients in each treatment group after therapy was started, but the mean rate of increase during treatment did not differ significantly from the rate during the pretreatment control period in either group. The occurrence of hypercalcemia or an excessive serum calcium x phosphorus-product did not correlate with the rate of change in renal function during treatment with either drug. We concluded that children receiving calcitriol are not at greater risk for an accelerated rate of renal function deterioration than are children treated with dihydrotachysterol. Furthermore, neither vitamin D analogue could be directly implicated as a cause of an accelerated rate of renal function deterioration when episodes of hypercalcemia were transient and occurred infrequently.

Histogenesis of hyperosteoidosis in 1,25(OH)2D3-treated rats fed high levels of dietary calcium

The purpose of this investigation was to determine by sequential quantitative morphometry the histogenesis of metaphyseal changes induced in rats fed high levels of dietary calcium and treated with pharmacologic doses of 1,25(OH)2D3. Young adult female rats were placed on a diet containing 2.5% calcium and 0.3% phosphorus and administered either ethanol or 135 ng (5 units) 1,25(OH)2D3 in ethanol IP daily for 10 days. Rats were terminated at Days 1, 2, 3, 4, 6, 8, and 10. At Day 1 the proximal tibias from rats treated with 1,25(OH)2D3 had a dramatic increase in osteoclasts/mm total trabecular surface perimeter compared with placebo-treated rats. Osteoclast numbers decreased in 1,25(OH)2D3-treated rats to the levels in placebo-treated rats by Days 3 and 4 and decreased significantly below placebo-treated levels at Days 6, 8, and 10. Active resorbing surface was significantly increased at Days 1 and 2 and decreased at Days 8 and 10 in 1,25(OH)2D3-treated rats compared with placebo-treated rats. From Day 4 through Day 10 in 1,25(OH)2D3-treated rats, there was a progressive increase in osteoblasts/mm total trabecular surface perimeter, osteoid surface, active osteoid surface, and metaphyseal osteoid. Metaphyseal osteoid increased markedly at Days 8 and 10 in 1,25(OH)2D3-treated rats and caused a significant increase in the amount of osseous tissue in the metaphysis. Metaphyseal mineralized bone, however, was not consistently affected by 1,25(OH)2D3 treatment. Serum calcium and phosphorus were elevated in 1,25(OH)2D3-treated rats at more time periods. In rats fed high levels of dietary calcium, repeated supraphysiologic doses of 1,25(OH)2D3 result in a net increase in metaphyseal osseous tissue, predominantly osteoid.(ABSTRACT TRUNCATED AT 250 WORDS)

Platelet X-ray microanalysis in patients with chronic renal failure

The platelet element content was determined by semiquantitative X-ray microanalysis in 6 patients with chronic renal failure. The patients showed a different degree of thrombocytopathy expressed by impaired adhesiveness, epinephrine-induced aggregation and platelet factor 3 availability. The microanalysis indicated significantly increased quantities of phosphorus and copper in patients' platelets. Sodium and zinc showed a decrease in about half of the patients, whereas iron was significantly increased in at least 50% of the patients. Magnesium and potassium did not show any difference from the control. The results of sulfur, chlorine and calcium did not reveal a consistent pattern.

Roentgenographic manifestations of maxillomandibular renal osteodystrophy

We examined 30 male chronic hemodialysis patients and 18 male controls without known bone or renal disease to determine the utility of maxillomandibular, non-dominant hand, shoulder and pelvis films in the evaluation of renal osteodystrophy. We used panoramic periapical radiographs to examine the maxilla and mandible and sensitive rapid processing films for the hand, shoulder and pelvis. Films were evaluated by experienced personnel without knowledge of the patients. There were significant differences between patients and controls in creatinine, urea nitrogen, total protein, albumin, alkaline phosphatase and phosphorus. Twenty-three patients had abnormal hand radiographs and 22 patients had abnormal jaw radiographs (p less than 0.05 vs. controls). Four patients had changes in the hands, but not in the jaw; 4 had opposite findings. Changes in the jaw tended to be more severe than in the hands in those with involvement of both. We concluded that dental and hand radiography are good screening techniques for evaluating bone disease. They may be useful in evaluating treatment for renal osteodystrophy.

Management of bone disease in the dialysis patient

Bone disease arises in dialysis patients from either secondary hyperparathyroidism or aluminum accumulation. Certain clinical features and biochemical characteristics may help distinguish these disorders, although a bone biopsy is required for a definitive diagnosis. Hyperparathyroidism is managed by correcting serum phosphorus (dietary phosphate restriction plus phosphate binding agents), raising serum calcium (appropriate dialysate Ca, oral Ca supplements, and vitamin D sterols), and by the direct effect of vitamin D on the parathyroid glands. When these fail, parathyroidectomy is necessary. Aluminum-related bone disease is prevented by eliminating aluminum from dialysate and minimizing the intake of aluminum-containing gels. Preexisting aluminum intoxication can be treated with repeated infusions of desferrioxamine.

[Plasma 25-OH D deficiency in Maghrebian children more than 10 years of age immigrated to France]

From 1984 Feb 1st to April 30, 63 blood samples were collected from children more than 10 years old in the pediatric unit of CHR de St-Etienne, and analysed for 25 OH D, calcium, phosphate, magnesium and alkaline phosphatase serum concentrations. Mean 25 OH D is lower (22,6 nmol/1) in 26 migrant children (24 from Maghreb and 2 from Turkey) than in 37 European children (mean = 48,6 nmol/1; p less than 0,001). Serum concentration is under 10 nmol/1 in 3 of the 37 Europeans (8%), versus 13 of the 26 Maghrebians (50%). Mean alkaline phosphatase and phosphate are significantly higher in the 36 boys than in the 27 girls. A significative positive correlation is found between alkaline phosphatase and phosphate (r = 0,535; p less than 0,01). There is no relation between age, month of assessment, sex, height, weight, place of late holidays and any of the measured serum values.