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R Bouillon

Publications and source records attributed to R Bouillon.

At least 361 records · Page 20Linked to original sources
PubMed1979

Radiogrammetry of the soft tissue at the index finger in acromegaly.

Measurements of the soft-tissue width and phalanx width at the index finger were made in 30 acromegalic patients and compared with values obtained in a large control population. The width of the phalanx, total finger width and soft-tissue thickness are significantly larger than expected and the soft-tissue index values are significantly lower than expected. An important overlap between normal and acromegalic values is found for the soft-tissue index and width of the proximal phalanx. The measurement which best discriminates acromegalics from normal is the total finger width. The soft-tissue thickness parameter is also very sensitive for the detection of acromegalic changes and has the advantage of not being sex and age dependent.

Acromegaly↗
PubMed1978

The heterogeneity of human Gc-globulin.

Gc-globulin or group-specific component, also known as the vitamin D-binding protein, was investigated by the combined use of electrofocusing and immunofixation. Serum of the Gc 2-2 type was found to contain a single protein band whereas serum of the Gc 1-1 type shows two bands with a lower isoelectric point. The Gc 1-2 type contains all three bands known as Gc-2 (pI 5.10), Gc-1Slow (pI 5.03), and Gc-1Fast (pI 4.95). Each apoprotein shows an anodal shift of about 0.07 pH unit after incubation with an excess of 25-hydroxycholecalciferol. After treatment with sialidase Gc-1Fast focuses in the position of Gc-1Slow, whereas the position of Gc-2 remains unchanged.

Alpha-Globulins↗
PubMed1978

Immunochemical measurement of the vitamin D-binding protein in rat serum.

The vitamin D-binding protein (DBP) was measured in rat serum using a single radial immunodiffusion technique. Normal serum levels at birth (74 +/- 11 mg/liter, mean +/- SD) were lower than during the last day of fetal life (130 +/- 14 mg/liter) and much lower than in adult rats. A marked sex difference in DBP occurred after puberty: male values (656 +/- 52 mg/liter) were significantly higher than female values (472 +/- 46 mg/liter). The sex difference could be abolished by either adult gonadectomy or transpharyngeal hypophysectomy. Implantation of a pituitary gland under the renal capsule in hypophysectomized male rats further decreased the DBP concentration, suggesting that PRL suppresses the DBP level. A similar decrease was also observed at the end of pregnancy and during lactation. Administration of androgens to either normal female or gonadectomized male rats increased their DBP concentration to the normal adult male level. The serum levels of total 25-hydroxyvitamin D did not fluctuate according to the concentration of DBP, indicating that the concentration of "free 25-hydroxyvitamin D" is not regulated at a constant level.

Age Factors↗
PubMed1978

Radioimmunoassay for parathyrin. Characterization of six different antigens and antisera.

We studied six different antisera to bovine or porcine parathyrin (parathyroid hormone, PTH), produced in rabbit, guinea pigs, sheep or goat, two of which are commercially available. The antisera were characterized with regard to species specificity, affinity and their ability to identify patients with primary hyperparathyroidism. In this heterologous radioimmunoassay system in which [125I]parathyrin is used as a tracer, some cross-reactivity of the antisera to the hormone or hormone fragments present in human serum was demonstrated. However, there is some overlap of serum immunoreactive parathyrin in patients with or without primary hyperparathyroidism. The results of this and other studies illustrate the necessity for a homologous radioimmunoassay for human parathyrin.

Animals↗
PubMed1977

25-hydroxy-vitamin-D in nephrotic syndrome.

Serum-25-hydroxy-vitamin-D (25-OHD) nephrotic syndrome (N.S.) without renal insufficiency (urinary protein excretion greater than 3-5 g/24 h/1-73 m2; glomerular filtration-rate greater than 80 ml/min/1-73 m2). Serum-25-OHD levels were low in patients with N.S. (mean 19 nmol/1, range 4-41 nmol/1), compared with a normal range of 25-200 nmol/1. Serum-concentrations of Gc-globulin--the binding protein for vitamin D and its metabolites (D.B.P.)--were significantly (P less than 0-001) lower in patients with N.S. (mean 340 mg/1, range 190-480 mg/1) than in non-proteinuric controls (mean 440 mg/1, range 376-510 mg/1, measured by radial immunodiffusion). In contrast to non-proteinuric urine, urine of all N.S. patients contained a large amount of 25-OHD-binding capacity; D.B.P. could be detected in all N.S. urines after concentration. Scatchard analysis of the urine demonstrated the presence of a low-affinity and a high-affinity binding protein (tentatively identified as albumin and D.B.P.). These results suggest an acquired deficiency of circulating 25-OHD in N.S. secondary to urinary loss of protein-bound 25-OHD. The biological relevance of the low 25-OHD levels is unknown. There was no clinical evidence of osteomalacia (X-ray, serum-alkaline-phosphatase); however, slightly elevated serum-parathyroid-hormone (P.T.H.) levels would be compatible with borderline vitamin-D depletion.

Adolescent↗
PubMed1977

Binding of 25-hydroxycholecalciferol in tissues.

Evidence is presented that the 5.8 S 25-hydroxycholecalciferol-binding protein found in the cytosols of all nucleated rat tissues is formed from two macromolecular substances: a heat-stable 4.1 S 25-hydroxycholecalciferol-binding protein which behaves identically with the serum 25-hydroxycholecalciferol-binding protein, and a cytosolic heat-labile protein which appears to sediment around 4 S and does not show binding properties for 25-hydroxycholecalciferol. The 5.8 S complex is formed in vitro by incubating cytosols with appropriate amounts of serum. The complex is dissociated by heating, leaving the serum 25-hydroxycholecalciferol-binding protein. Complex formation also occurred with serum 25-hydroxycholecalciferol-binding proteins from other species. The widespread occurrence of the 4 S cytosolic component raises the possibility that the high affinity binding proteins for 25-hydroxycholecalciferol observed in nucleated tissues are largely the result of plasma contamination.

Animals↗
PubMed1977

The measurement of the vitamin D-binding protein in human serum.

The concentration of the vitamin D-binding protein was measured in human serum by single radial immunodiffusion. Normal serum concentrations were slightly higher in normal women than in normal men. No race-related difference was found between white people from Belgium and black people from Zaire. Lower concentrations were found in cord serum and in patients with cirrhosis of the liver. Increased serum levels were observed during pregnancy or during the intake of estro-progestogens. The serum level of the vitamin D-binding protein was not altered in various diseases of calcium metabolism (primary osteoporosis, primary and secondary hyperparathyroidism, rickets, osteomalacia or vitamin D intoxication). No correlation was found between serum levels of 25-hydroxy vitamin D and those of its binding protein. From these data the following conclusions can be drawn: 1) The serum concentration of the vitamin D-binding protein (about 6.10(-6)M) largely exceeds the normal serum concentration of 25-hydroxy vitamin D (about 4.10(-8)M), so that this protein is normally for less than 1% saturated, 2) Normal serum levels of the vitamin D-binding protein were observed in several diseases of calcium metabolism, and 3) The free concentration of 25-hydroxyvitamin D is not regulated at a constant level.

Adult↗
PubMed1977

25-hydroxyvitamin D and its binding protein in maternal and cord serum.

Serum calcium, phosphorus, albumin, total protein, 25-hydroxyvitamin D (25OHD) and the vitamin D-binding protein (DBP) were measured in 30 cord sera and in 30 sera obtained simultaneously from their respective mothers. The maternal serum concentration of 25OHD (14.0 +/- 6.9 microgram/l, mean +/- SD) and of DBP (574 +/- 72 mg/l) were significantly higher than the respective cord serum concentration (8.0 +/- 4.4 microgram/l and 268 +/- 39 mg/l). The calculated concentration of "free 25OHD," however, was slightly but significantly higher in cord serum (0.44 +/- 0.24 ng/l) than in maternal serum (0.34 +/- 0.18 ng/l). Serum calcium and phoshporus were lower in maternal than in cord serum. A highly significant positive correlation was found between maternal and cord serum concentration of DBP (r = 0.59), total 25OHD (r = 0.79), "free 25OHD" (r = 0.86) and phosphorus (r = 0.73). These data indicate that the concentration of DBP is important for the evaluation of the placental transfer of 25OHD. Indeed, the concentration of "free 25OHD" is slightly higher in cord serum than in maternal serum, despite the maternal-to-fetal gradient of total 25OHD. The low fetal concentration of DBP is also unfavorable for the fetal storage of 25OHD during intrauterine life.

Calcium↗
PubMed1976

The transport of vitamin D in the serum of primates.

"Transcalciferin" (the serum transport protein for cholecalciferol and related substances) of two New World monkeys, Cebus apella and Cebus albifrons, was found to be immunologically identical with the transcalciferin of other monkeys and partially with that of man. In contrast with the alpha-globulin mobility of the transcalciferin of other primates, the transcalciferin of cebus monkey has the electrophoretic mobility of albumin. Most of the serum 25-hydroxycholecalciferol was precipitable with isolated monospecific anti-(human transcalciferin) gamma-globulins but not with anti-(human albumin) gamma-globulins. These results indicate that the transport of 25-hydroxycholecalciferol in the cebus monkey is not due to albumin itself but to transcalciferin with the electrophoretic mobility of albumin. Similar variants of transcalciferin also exist in man.

Animals↗
PubMed1976

The purification and characterisation of the human-serum binding protein for the 25-hydroxycholecalciferol (transcalciferin). Identity with group-specific component.

The binding protein for 25-hydroxyvitamin D3 has been isolated from human serum by monitoring the recovery of 3H-labeled 25-hydroxyvitamin D3. After a 500-fold purification a pure protein was obtained as judged from the constant specific activity (ratio of absorbance versus radioactivity) on agarose and DEAE-Sephadex chromatography and on the presence of a single band on both cellulose acetate and polyacrylamide gel electrophoresis. The molecular weight of the purified protein was measured by gel filtration on agarose (56000), Sephadex G-75 (58000) and dodecylsulfate-polyacrylamide gel electrophoresis (56000). On sucrose gradient ultracentrifugation a sedimentation coefficient of 4.1 S was found. The isoelectric point was 4.89 S on isoelectric focusing. The stability of the protein at 60 degrees C was enhanced by the presence of excess 25-hydroxyvitamin D3. On tandem crossed immunoelectrophoresis the purified binding protein was found to be identical to the one present in whole serum. The activity of the isolated protein was demonstrated by a Ka at 4 degrees C of 1.2 X 10(10) l-mol-1. A binding capacity of 0.8 binding site/molecule was measured on a Sephadex G-25 column. During immunological studies with this protein it became evident that the binding protein is identical with another serum protein known as group-specific component (Gc). In analogy to other serum binding proteins we propose to call this group-specific component/25-hydroxyvitamin-D3-binding protein transcalciferin.

Amino Acids↗
PubMed1976

Second antibody chemically linked to cellulose for the separation of bound and free hormone: an improvement over soluble second antibody in gonadotrophin radioimmunoassay.

Coupling the second antibody to a solid pase (DASP) was found to be a definite improvement over the classical technique of soluble second antibody (DA) separation of bound and free hormone in the radioimmunoassays of gonadotrophins in plasma or in serum. The duration (2.5 to 7.5 min) and the pH (10.5 to 12.5) of the cyanogen bromide activation of microcristalline cellulose did not affect the coupling capacity or the immunoreactivity of the second antibody, nor did it augment aspecific adsorption of free gonadotrophin on the cellulose matrix. Precision of duplicates was comparable for both methods but the accuracy and the detection limit of the solid phase system were higher due to a better separation of bound and free hormone, to the lower blank value and to the absence of aspecific interference of protein concentration. Cost was lower since much less second antibody was needed in the solid phase system than in the soluble system and since the experimental procedures were simplified by the absence of prozoning effect and the solid nature of the cellulose matrix.

Animals↗
PubMed1976

Hormonal and biochemical changes in patients successfully operated for primary hyperparathyroidism.

Six patients with primary hyperparathyroidism were studied during the first seven days after the operative removal of the parathyroid adenoma with special emphasis on biochemical and hormonal changes during the first 24 h. Serum parathyroid hormone (PTH) levels fell abruptly after the parathyroidectomy and normalized within 3 h. The half-life of the biologically inert c-terminal PTH-fragment (M.W. 7000-7500) was calculated to be about 180 min. No significant changes in serum calcitonin levels were found. The serum phosphorus levels, which were already low pre-operatively, decreased transiently but significantly during the first 90 min after the removal of the parathyroid adenoma. This fall in serum phosphorus preceded a slow decrease of the calcaemia. During the first post-operative week the calcaemia continued to decline, while serum phosphorus levels increased. The pre-operative cholesterol levels were low compared to age-paired normal Belgians. During the first post-operative week the cholesterolaemia decreased even more, whereas at long term follow-up a clearcut increase of the serum cholesterol levels has to be expected.

Adult↗
PubMed1976

Measurement of 25-hydroxyvitamin D3 in serum.

We describe a method for measuring 25-hydroxyvitamin D3 in serum. Extraction with dichloromethane/methanol (2/1 by vol), followed by chromatography on a column of Sephadex LH-20, resulted in an overall analytical recovery of 82% +/- 3.5% (SD). Diluted normal rat serum was used as binding protein because it contains a transport protein that has both a high affinity (Ka = 2 X 10(10) liter/mol) and a high capacity (3 X 10(-6) mol/liter) for 25-hydroxyvitamin D3. There is no advantage in using more complex binding proteins derived either from rachitic animals or from cytosol preparations. Concentrations of 25-hydroxyvitamin D3 (13.4 +/- 4 mug/liter) in the serum of apparently normal Belgian subjects are lower than those reported for North Americans, but resemble those reported for the United Kingdom.

Animals↗