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Biomedical subjects

P De Moor

Publications and source records attributed to P De Moor.

At least 19 recordsLinked to original sources
PubMed1988

More familial leukaemia in ALL patients with both unexplained high transcortin levels and an HLA antigen Cw3.

In a group of 74 adult ALL patients 25 had a transcortin level greater than or equal to 3 SD above the normal mean, 15 expressed an HLA-Cw3 antigen and 11 combined both characteristics. In this subgroup of 11 ALL patients, five had familial leukaemia, i.e. at least one relative with acute leukaemia or lymphoma. On the other hand, only three examples of familial leukaemia were found in a series of 59 ALL patients with one or none of these two characteristics (relative risk: 15.6; P less than 0.001).

Adult↗
PubMed1987

Evidence for an interaction of insulin and sex steroids in the regulation of vitamin D metabolism in the rat.

Vitamin D metabolites and vitamin D-binding protein (DBP) were measured in non-diabetic rats and in rats made diabetic with streptozotocin. The animals were studied in the intact state, after gonadectomy and during pregnancy. In male non-diabetic rats the serum concentrations of 1,25-dihydroxyvitamin D3 (1,25-(OH)2D3) and DBP decreased after orchidectomy and were restored by treatment with testosterone. In female non-diabetic rats, these parameters increased after ovariectomy. Increased 1,25-(OH)2D3 and decreased DBP concentrations were found during pregnancy in non-diabetic rats. After the induction of diabetes in intact rats of both sexes, the concentration of DBP decreased, but a significant decrease in the concentration of 1,25-(OH)2D3 was found in male animals only. After ovariectomy, however, 1,25-(OH)2D3 decreased also in female diabetic rats. Both orchidectomy and insulin deficiency depressed serum concentrations of 1,25-(OH)2D3 (-22 and -45% respectively) and DBP (-14 and -29% respectively), but the effects of insulin deficiency were greater than those of androgen withdrawal. Moreover, the testosterone concentration was twofold lower in intact male diabetic rats than in non-diabetic animals. Insulin, but not testosterone treatment, however, restored DBP and 1,25-(OH)2D3 concentrations in diabetic rats, and insulin was effective in intact as well as in gonadectomized animals. This study shows that insulin deficiency decreases the concentrations of DBP and 1,25-(OH)2D3 in the rat, and that these decreases are facilitated by androgens, but counteracted by oestrogens.

Animals↗
PubMed1986

Phylogenetic study of transcortin using monoclonal antibodies.

We produced monoclonal antibodies that recognise three distinct epitopes of human transcortin. These epitopes are present on transcortin of humans with normal and altered transcortin levels, as well as on a variant with lower affinity for cortisol. One epitope is present on transcortin of Old World Monkeys and apes, the others are only present on transcortin of apes. The epitopes are not present on transcortin of other species. These results indicate that human transcortin contains a highly evolved and a more conserved part.

Animals↗
PubMed1986

Pancreatic secretion in man with subclinical vitamin D deficiency.

The effects of subclinical vitamin D deficiency and vitamin D supplementation on oral glucose tolerance and secretion of pancreatic hormones were studied in 10 diphenylhydantoin-treated epileptic patients and 15 geriatric patients. Their mean serum concentrations of 25-hydroxyvitamin D3 and 1,25-dihydroxyvitamin D3 decreased markedly, but returned to normal within 2 weeks of oral supplementation with 25-hydroxyvitamin D3. The serum concentration of ionized calcium was within the normal range before treatment, and remained unchanged. Serum parathyroid hormone was increased during vitamin D deficiency, but decreased significantly (p less than 0.05) afterwards. In vitamin D-deficient epileptic and geriatric patients, the 2- and 3-h insulin levels after glucose ingestion were increased when compared with control values, and glucagon secretion was not suppressed by glucose. Oral glucose tolerance of both groups of patients did not change after 25-hydroxyvitamin D3 supplementation. Insulin secretion remained unchanged in geriatric patients, but was reduced to normal values in epileptic patients. Glucagon suppressibility by glucose was partly restored after vitamin D supplementation in epileptic patients but not in geriatric patients. In contrast to that observed in severely vitamin D-deficient rats or rabbits, correction of subclinical vitamin D deficiency failed to enhance insulin secretion or to improve glucose tolerance in man.

Age Factors↗
PubMed1986

Steroid-carrier proteins in patients with multiple myeloma.

Patients with multiple myeloma have transcortin levels lower than normal. This is due in essence to a subgroup of patients producing IGG heavy chains with lambda light chains. Patients producing IGG with predominantly kappa light chains have almost normal transcortin levels. On the other hand, the binding activity of the steroid binding beta globulin (SB beta G) of the kappa type of multiple myeloma is significantly higher than the steroid binding of the lambda type of multiple myeloma. The serum levels of vitamin D binding protein (DBP) fall in the normal range.

HLA Antigens↗
PubMed1986

Decreased free 1,25-dihydroxycholecalciferol index in patients with the nephrotic syndrome.

The serum concentrations of calcium, phosphorus, parathyroid hormone, vitamin D3 metabolites and their transport protein (DBP) were measured in 18 patients with the nephrotic syndrome (mean daily proteinuria 8.8 g). The glomerular filtration rate was normal in 13 patients while the remaining 5 had a mild degree of renal failure. The serum concentrations of total protein, albumin and DBP were significantly decreased in patients with the nephrotic syndrome. The serum calcium concentration was decreased but the calculated ionized calcium concentration remained normal. The serum concentrations of 25-hydroxycholecalciferol (5.3 +/- 3.1 micrograms/l) and 1,25-dihydroxycholecalciferol [1,25-(OH)2D3 (20 +/- 12 ng/l)] were significantly lower in patients with the nephrotic syndrome and normal glomerular filtration rates than in normal controls (14.4 +/- 4 micrograms/l and 42 +/- 13 ng/l, respectively). The free 1,25-(OH)2D3 index was also significantly below normal (0.9 +/- 0.4 vs. 1.8 +/- 0.4). Total and free 1,25-(OH)2D3 were still further reduced in patients with mild renal failure. The nephrotic syndrome thus results in mild vitamin D depletion with decreased free 1,25-(OH)2D3 concentrations but generally without secondary hyperparathyroidism.

Adolescent↗
PubMed1986

Transcortin and vitamin D-binding protein levels in mouse serum.

The influence of age, sex and strain on the serum concentration of transcortin (corticosteroid-binding globulin) and vitamin D-binding protein (DBP) in mice was investigated. The effect of age was studied in two strains, C57BL/6JPfd and BALB/cmHeAPfd. The concentration of transcortin and DBP increased with age. In young animals the concentration of each protein showed a significant strain difference, which disappeared in older mice for DBP, but not for transcortin. In 7-day-old animals, no sex difference was observed for either protein, but in older animals a clear sex difference was found for transcortin. Adult males tended to have somewhat higher levels of DBP than adult females, but this difference was significant only on day 70. The variation in transcortin and DBP levels was further investigated in a large number of mouse strains. The DBP concentration did not markedly vary among strains (5.98-9.65 mumol/l in males and 5.08-8.85 mumol/l in females). Transcortin, however, showed marked strain variations, ranging from 0.72 to 2.06 mumol/l in males and from 1.02 to 4.55 mumol/l in females and there was a significant correlation (r = 0.66, n = 26, P less than 0.001) between the mean transcortin levels in males and females of different strains. Interstrain variation was much higher than intrastrain variation or variation among related strains, suggesting that the transcortin concentration is largely controlled by genetically determined factors. There was a significant correlation (r = 0.82, n = 9, P less than 0.01) between the mean corticosterone and transcortin concentrations (measured at 21.00 h).(ABSTRACT TRUNCATED AT 250 WORDS)

Aging↗
PubMed1986

Vitamin D metabolites and their binding protein in adult diabetic patients.

Vitamin D metabolites and vitamin D-binding protein were measured in the serum of nonketotic Bantu and Caucasian insulin-requiring diabetic subjects from Zaire and Belgium, respectively. In Caucasian diabetics, whether untreated (N = 18) or insulin treated (N = 26), no abnormalities were found. The Bantu diabetics (N = 20) were more insulin-deficient and had a poorer glucose control than the Caucasians. They presented, compared with Bantu controls, a significant decrease in the serum concentrations of 25-hydroxyvitamin D3 (26 +/- 10 vs. 35 +/- 14 micrograms/L, P less than .01), 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] (38 +/- 15 vs. 58 +/- 17 ng/L, P less than .001), and vitamin D-binding protein (303 +/- 55 vs. 356 +/- 41 mg/L, P less than .001). The decreased concentrations of vitamin D metabolites in the adult Bantu diabetic patients may be partly explained by a concomitant decrease in the concentration of vitamin D-binding protein, possibly due to insulin deficiency. The ratio between the molar concentrations of 1,25-(OH)2D3 and vitamin D-binding protein, used as an index of the free hormonal level, was also decreased, in association with a decreased serum calcium level. In conclusion, no abnormalities in vitamin D metabolism were found in Caucasian insulin-dependent diabetics, whereas low serum 1,25(OH)2D3 concentrations and hypocalcemia were found in poorly controlled Bantu diabetic subjects.

Adult↗
PubMed1985

Transcortin modulates the effect of cortisol on mitogen-induced lymphocyte proliferation and immunoglobulin production.

In the present study we investigated whether transcortin modulates the in vitro effects of cortisol on the proliferation of human peripheral blood mononuclear cells (PBMC) stimulated by different mitogens and on mitogen-induced polyclonal immunoglobulin production. Physiological doses of cortisol (10-1000 nM) strongly inhibited the proliferation of PBMC stimulated by the monoclonal antibody OKT3 or by phytohemagglutinin. Addition of pure cortisol-free transcortin significantly reduced these inhibitory effects in a dose dependent manner. Transcortin (1 microM) caused a 3- to 4-fold reduction of the effects of 100 nM cortisol. Transcortin alone had no influence on the proliferation of stimulated PBMC. Polyclonal immunoglobulin production by PBMC stimulated with pokeweed mitogen was enhanced by physiological does of cortisol. A concentration of 100 nM cortisol caused an increase of immunoglobulin G and M production of 81 and 55% respectively. This effect was abolished by addition of 1 microM transcortin to the cultures, whereas transcortin alone had no effect. These results indicate that an evaluation of the effect of corticoids on lymphoid tissues should be based on the free cortisol level rather than on the total cortisol concentration.

Adult↗
PubMed1985

Transcortin and alpha 2u-globulin messenger RNA activities during turpentine-induced inflammation in the rat.

Previously we have shown that the serum concentration of transcortin and alpha 2u-globulin markedly decreases during turpentine-induced inflammation. In the present study transcortin and alpha 2u-globulin mRNA from healthy rats and from animals with inflammation was translated in a rabbit reticulocyte lysate system. Female rats had higher levels of translatable transcortin mRNA than male animals and the level of mRNA for transcortin and alpha 2u-globulin decreased rapidly during inflammation. These results indicate that the sex difference in the serum level of transcortin and the changes in serum transcortin and alpha 2u-globulin during inflammation are mainly determined by differences in the mRNAs in the liver.

Alpha-Globulins↗
PubMed1985

Changes in the distribution and composition of high-density lipoproteins in primary hypothyroidism.

The distribution and composition of high-density lipoprotein (HDL) subclasses were investigated in 14 women with severe hypothyroidism who were studied before and during treatment. The plasma concentrations of triglycerides, total cholesterol, HDL cholesterol, and of the apoproteins (apo) A-I, B, and E were increased in the hypothyroid state, while the apo A-II levels did not change significantly. After normalization of the thyroid function tests, the lipid and apoprotein levels were similar to those of normal individuals. Isopycnic ultracentrifugation in the density range 1.020 to 1.210 g/mL showed increases of both cholesterol and apo B in very-low-density lipoprotein (VLDL) and in low-density lipoprotein (LDL). The distribution of the HDL subclasses was modified in the hypothyroid subjects; both the less dense HDL fraction (d 1.063 to 1.100 g/mL; HDL2b), and the denser subclass (d 1.150 to 1.210 g/mL; HDL3b+3c) were increased, while the intermediate density subfraction (d 1.100 to 1.150 g/mL; HDL2a+3a) did not vary significantly. This redistribution of the HDL subfractions was associated with increased concentrations of cholesterol, phospholipid, and apo A-I in HDL2b, and of phospholipid and apo A-I in HDL3b+3c. Treatment of hypothyroidism decreased the concentrations of these fractions, and HDL2a+3a became the major HDL subclass in the euthyroid state. The particle sizes within HDL subfractions, measured by polyacrylamide gradient gel electrophoresis, were identical in the untreated and treated patients. The increased mass of protein and lipid within HDL2b and HDL3b+3c could therefore be attributed to an accumulation of identical-sized particles. The overall lipid and protein composition of the HDL lipoproteins was similar before and during treatment.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1985

1,25-Dihydroxyvitamin D and vitamin D-binding protein are both decreased in streptozotocin-diabetic rats.

Calcium and vitamin D metabolism were studied in streptozotocin-treated rats up to 10 days after the induction of diabetes. Proteinuria, hypercalciuria, and hyperphosphaturia appeared as early as 3 days after diabetes induction and were reversed by insulin. The serum proteins and fasting calcium concentrations were decreased in untreated diabetic rats. The concentration of serum vitamin D binding protein (DBP) was higher in male than in female control rats (mean +/- SD; 555 +/- 73 vs. 348 +/- 28 mg/liter, P less than 0.001). When sequentially measured in male untreated diabetic rats, DBP concentration steadily decreased. Compared with control values, DBP was reduced 19%, 28%, and 32% on days 3, 6, and 10, respectively, after induction of diabetes in male rats. In female animals, DBP was reduced 22% on day 10 of diabetes. DBP concentration was corrected by insulin treatment of diabetic rats and remained normal in streptozotocin-treated animals that did not develop diabetes. The serum concentration of 25-hydroxyvitamin D3 was similar in both sexes and was not affected by diabetes. Like DBP, the concentration of total 1,25-dihydroxyvitamin D3 [1,25-(OH)2D3] was higher in male than in female control rats (120 +/- 24 vs. 96 +/- 17 ng/liter, P less than 0.001), but 10 days after induction of diabetes this concentration decreased by 37% and 29% in male and female rats, respectively. The free 1,25-(OH)2D3 concentration, estimated from the molar 1,25-(OH)2D3/DBP ratio, was similar in both sexes and was not decreased by diabetes. We conclude that experimental diabetes in the rat induces a decrease in DBP concentration and a concomitant decrease in total but not in free 1,25-(OH)2D3 concentrations. This may indicate that diabetes decreases circulating 1,25-(OH)2D3 concentrations through alterations in DBP levels.

Animals↗