PubMed Health⌕ Search

Biomedical subjects

F Glorieux

Publications and source records attributed to F Glorieux.

17 recordsLinked to original sources

Effects of locally applied transforming growth factor-beta1 on distraction osteogenesis in a rabbit limb-lengthening model.

In this study we tested the effect of locally applied transforming growth factor-beta1 (TGF-beta1) on distraction osteogenesis in rabbits. A total of 61 rabbits were studied. Seven days after tibial osteotomy, distraction was started at a rate of 0.25 mm/12 h for 3 weeks. Starting with distraction, TGF-beta1 was applied in four different dosages (0, 10, 20, and 40 ng/day) at the site of osteotomy through a catheter connected to a subcutaneously implanted miniosmotic pump. Rabbits were killed at the end of the distraction period or 3 weeks later, and histological, densitometric, and biomechanical parameters were assessed. TGF-beta1 treatment had no detectable effect on bone mineral density or histologically determined bone volume in the distraction gap but it increased the amount of fibrous tissue in the callus region. Load to failure in uniaxial tension tended to be lower in TGF-beta1-treated animals. In conclusion, TGF-beta1 treatment during distraction osteogenesis did not have a beneficial effect in this model.

Absorptiometry, Photon↗

Interpretation of bone mineral density values in pediatric Crohn's disease.

Patients with Crohn's disease (CD) often have low bone mineral density (BMD) for their chronological age (CA). However, pediatric cases frequently have growth failure and delayed bone age (BA) and height age (HA). Do they really have the amount of osteoporosis as measured by BMD and calculated for their CA? The aim was to compare z-scores for BMD in relation to CA and z-scores corrected for BA or height age in pediatric patients. A group of 43 pediatric patients (mean age, 12 years; 14 girls, 29 boys) with CD in remission, prospectively had BMD (measured by dual energy x-ray absorptiometry) and BA. Abnormally low z-score for BMD (below 2 standard deviation [SD] for CA was found in 19 patients (44%). Among these, 9 patients (21% overall) had a BA of more than 2 SD lower than their CA and 12 had height age at least 2 years below CA. When the BMD z-score in these patients was corrected for their BA and height age, 6 of 9 and 8 of 12 patients had a normal BMD. In conclusion, when corrected for BA or CA delay, BMD was abnormal in 26 to 30% rather than 44% of cases. Correct assessment of BMD in Crohn's disease patients with bone age delay requires interpretation in terms of BA or HA, rather than CA.

Absorptiometry, Photon↗

A prospective trial of phosphate and 1,25-dihydroxyvitamin D3 therapy in symptomatic adults with X-linked hypophosphatemic rickets.

Current treatment of X-linked hypophosphatemia (XLH) employs the combined administration of oral phosphate and 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3]. Although this drug regimen significantly improves the clinical course of the disease in children, the value of medical treatment in symptomatic adults with XLH has not been established. We, therefore, investigated the clinical, biochemical, and histological responses to phosphate and 1,25-(OH)2D3 in 16 symptomatic adult patients with XLH followed for a mean of 4.2 yr. Eighty-seven percent of the patients had an improvement in bone or joint pain with therapy. There was a significant increase in mean serum phosphate (from 0.61 +/- 0.03 to 0.77 +/- 0.03 mmol/L) and urinary calcium excretion (from 2.45 +/- 0.38 to 4.39 +/- 0.44 mmol/day) with treatment. Pretreatment bone biopsies demonstrated findings characteristic of osteomalacia, including abnormally increased osteoid volume and decreased mineral apposition rates. Treatment was accompanied by a significant decrease in osteoid thickness as well as a reduction in mean osteoid volume. However, therapy did not completely normalize these parameters. Disease severity, as assessed by histomorphometric parameters, did not correlate with any pretreatment serum or urinary biochemical measurement, but did seem to correlate with symptom score. Although most patients tolerated therapy without difficulty, 1 patient developed tertiary hyperparathyroidism during treatment and renal insufficiency that progressed despite cessation of therapy. This study provides evidence that therapy with oral phosphate and 1,25-(OH)2D3 in symptomatic adults with XLH can result in significant clinical and histomorphometric improvement.

Adolescent↗

Vitamin D metabolism in rats with adjuvant-induced arthritis.

Adjuvant-induced arthritis in rats shares many of the features of humans with rheumatoid arthritis, including the development of osteopenia in areas distal to erosive joint disease. We established adjuvant arthritis in male and female Sherman strain rats and then studied external calcium balances and vitamin D metabolism during the period of acute active clinical, serologic, and pathologic arthritis and osteopenia and in the preclinical period. While ingesting a calcium-sufficient vitamin D-replete diet (0.6% calcium, 0.65% phosphorus, and 2.2 IU D3 per g food), female rats with arthritis demonstrated reduced calcium balance (arthritic, 36 +/- 8 versus control, 169 +/- 13 mg per 6 days, p less than 0.02) because of inefficient gastrointestinal absorption of calcium (arthritic 9.7% versus control 37%). This was associated with calcitriol deficiency (arthritic 52 +/- 7 versus control 70 +/- 10 pg/ml) and reduced osteocalcin levels. Male rats with arthritis demonstrated an inability to raise serum calcitriol levels to the same degree as control rats (200 +/- 30 versus 440 +/- 70, respectively) while ingesting a calcium-deficient diet (0.002% calcium, 0.34% phosphorus, and 2.2 IU D3 per g food) and also had reduced balance (59 +/- 7 versus 85 +/- 10 mg per 6 days, respectively) due in part to decreased efficiency of absorption (55 versus 67%). No abnormalities in calcium balance or in serum calcitriol levels on the sufficient diet were present in the preclinical period. Physiologic calcitriol replacement to arthritic female rats increased osteoid available for mineralization and increased mineral apposition rates.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Human neonatal hypocalcemia.

Hypocalcemia is commonly observed in the neonatal period and is usually transient from a few days to a few weeks. On only rare occasions is neonatal hypocalcemia permanent and secondary to congenital hypoparathyroidism caused by either isolated absence of parathyroid glands or in association with other malformations. Most cases of neonatal hypocalcemia fall into one of two clinical categories. Namely early neonatal hypocalcemia occurs in 24-48 h of life and it is usually observed in premature infants or infants of diabetic mothers. Late neonatal hypocalcemia is observed at the end of the first week of life. In addition of these two major categories, neonatal hypocalcemia may occur in association with hypomagnesemia.

Female↗

Bridging markers defining the map position of X linked hypophosphataemic rickets.

Hypophosphataemic rickets is commonly an X linked dominant hereditary disorder associated with a renal tubular defect in phosphate transport and bone deformities. The gene causing this disorder has been mapped to Xp22.31----p21.3 by using cloned human X chromosome sequences identifying restriction fragment length polymorphisms (RFLPs) in linkage studies of affected families. The hypophosphataemic rickets gene locus (HPDR) was previously mapped distal to the X linked polymorphic locus DXS41 (99.6) but its position in relation to the distal loci DXS43 (D2) and DXS85 (782) was not established. In order to obtain a precise mapping of the disease locus in relation to these genetic loci, additional affected families informative for these X linked markers have been investigated. The combined results from the two studies have established linkage with the loci DXS41 (99.6) and DXS43 (D2); peak lod score for DXS41 (99.6) = 7.35, theta = 0.09, and peak lod score for DXS43 (D2) = 4.77, theta = 0.16. Multilocus linkage analysis mapped the hypophosphataemic rickets gene distal to the DXS41 (99.6) locus and proximal to the DXS43 (D2) locus, thereby revealing two bridging genetic markers for the disease.

Chromosome Mapping↗

Mapping of human X-linked hypophosphataemic rickets by multilocus linkage analysis.

Eleven families with X-linked dominant hypophosphataemic rickets (HPDR) have been typed for a series of X chromosome markers. Linkage with probe 99.6 (DXS41) was demonstrated with a peak lod score of 4.82 at 10% recombination. Multilocus linkage analysis showed that HPDR maps distal to 99.6; this probe has previously been located at Xp22.31-p21.3 by in situ hybridisation. In the mouse hypophosphataemia (Hyp) maps to the distal part of the X chromosome; our location in man is consistent with a scheme which relates the mouse and human X chromosomes by two rearrangements. No marker has yet been found which shows no recombination with HPDR.

Animals↗

[Metabolism of minerals and vitamin D in the pregnant woman and the fetus].

The mineral metabolism in the fetus and pregnant woman is described with reference to data from the medical literature and personal studies. As soon as the twenty-eighth week of gestation, a concentration gradient is established between mother and fetus for calcium, phosphorus and magnesium, with higher levels in the fetus. The vitamin D content of the fetus is dependent on that of the mother; in France, where food is not supplemented, vitamin D deficiency is common in mothers and neonates, especially during the winter and spring and in areas where sunlight is scarce. Vitamin D supplementation is therefore required during the last trimester of gestation.

Animals↗

Hypocalcemia in infants of diabetic mothers. Studies in circulating calciotropic hormone concentrations.

Twenty-two infants of diabetic mothers (IDM) were studied and were divided into two groups: a first group of 14 IDM did not receive vitamin D3 and was studied at birth and at 2, 24, 48 and 120 hours; a second group was given daily dosage of 60 microgram of vitamin D3 from 3 hours to 120 hours and was studied at 2 hours and 120 hours. In the first group, serum calcium levels decreased markedly during the first 24 hours of life (mean +/- SD: 1.77 +/- 0.3 mmol/l, p less than 0.01) and remained low at 5 days. Serum phosphorus levels remained normal but serum magnesium levels decreased significantly at 24 hours (mean +/- SD: 0.64 +/- 0.108 mmol/l, p less than 0.01) and returned to normal at 5 days. Serum immunoreactive parathormone levels increased consistently to high levels at 24 hours and remained elevated at 120 hours (p less than 0.001). Serum immunoreactive calcitonin levels increased at 24 hours (p less than 0.001) and decreased at 120 hours to low or undetectable values in all infants. In group II, serum 25O-HD levels and 1.25 OH2 D levels increased significantly (p less than 0.001) respectively to 27.2 +/- 2.7 ng/ml and 114 +/- 20 pg/ml at 5 days. The results of this study show hypocalcemia to be a common event in IDM during the first days of life and furthermore hypophosphatemia, hypoparathyroidism, hypomagnesemia or defect of vitamin D metabolism would not seem to be the main etiological factors.

Calcifediol↗

Comparative activity of arylsulphatases A and B on two synthetic substrates.

Rat liver and human skin fibroblasts arylsulphatase A and B activities on both 4-methylumbelliferyl sulphate and 4-nitrocatechol sulphate were compared. The intracellular distribution of activity differed markedly when 4-methylumbelliferyl sulphate was used from that observed with 4-nitrocatechol sulphate. No discrimination between control and metachromatic leucodystrophy or mucopolysaccharidosis (type VI) could be achieved when 4-methylumbelliferyl sulphate was used as substrate. These results contrast sharply with those obtained with 4-nitrocatechol sulphate and cast doubt on the validity of 4-methylumbelliferyl sulphate as substrate for the determination of arylsulphatase A and B activities.

Animals↗

Loss of a parathyroid hormone-sensitive component of phosphate transport in X-linked hypophosphatemia.

Mutant hemizygotes with X-linked hypophosphatemia lack a parathyroid hormone-sensitive component of inorganic phosphate transport in kidney; female heterozygotes retain a variable proportion of this type of transport. The residual mechanism for reabsorption in affected males allows inorganic phosphate efflux from the kidney to urine so that net "secretion" is sometimes observed; the latter is directly proportional to the serum concentration of inorganic phosphate. Calcium acts on the kidney tubule to enhance net reabsorption by this component of inorganic phosphate transport.

Adolescent↗

Serum parathyroid hormone in X-linked hypophosphatemia.

Serum immunoreactive parathyroid hormone(IPTH) is normal in patients with X-linked hypophosphatemic rickets who are not treated with phosphate salts. Phosphate raises IPTH in these patients. Endogenous IPTH does not influence the existing defect in tubular reabsorption of phosphate in male patients.

Calcium↗