Biomedical subjects

F de Boisvilliers

Publications and source records attributed to F de Boisvilliers.

3 recordsLinked to original sources

PubMed1999

Hemorheology of growth hormone-deficient adults.

Growth hormone deficiency (GHD) in adults results in alterations of body composition and metabolism associated with a lowered insulin sensitivity and an increased cardiovascular risk. Since hemorheologic disturbances (putative factors of vascular risk) are found in the insulin-resistance syndrome, we investigated blood rheology in 9 adults GHDs (5 men, 4 women; age 37.9+/-4.7 years; body mass index 30.23+/-3.2 kg/m2) compared with 23 lean controls and 37 controls matched for sex, age and body mass index. While this sample of GHDs exhibits the typical metabolic picture of this syndrome (upper body overweight with a waist-to-hip ratio at 0.91+/-0.07; low HDL cholesterol at 1.07+/-0.09 mmol x l(-1); low insulin sensitivity with the minimal model technique at 3.3+/-1.29 min(-1)/(microU/ml) x 10(-4)) they have similar values of blood viscosity at either native or corrected hematocrit, similar hematocrit, similar red cell rigidity viscometric index, similar red cell aggregation parameters than overweight matched controls. There is only a nonsignificant tendency for plasma viscosity to be higher in GHDs: this tendency becomes significant when women are considered alone (GHDs: 1.44+/-0.04 mPa.s; controls: 1.31+/-0.04 mPa.s, p<0.05) while it is no longer found in men. This study suggests that GHDs exhibit the classical hemorheological disturbances of non-GHD individuals with the same degree of obesity. There is no evidence for a further impairment of blood rheology associated with the specific metabolic and endocrine pattern of GHDs that may be involved in their increased vascular risk.

Adult↗

PubMed1995

The natural protein kinase C alpha mutant is present in human thyroid neoplasms.

An altered protein expression of Ca(2+)-dependent protein kinase C (PKC) isoforms and a point mutation in the PKC alpha cDNA (position 908 of the nucleotide sequence, position 294 of the amino acid sequence, substitution of an aspartic acid by a glycine) have been previously described in a subpopulation of human pituitary tumors. In this work, we screened 16 thyroid tissue samples (four follicular adenomas, five colloid adenomas, three papillary carcinomas, one follicular carcinoma and three normal tissues adjacent to the tumors) for the presence of the PKC alpha point mutation and for PKC alpha, beta 1, beta 2, epsilon and delta protein expression. Screening for the presence of the PKC alpha mutant was performed by a subcloning technic. The polymerase chain reaction products were generated using reverse-transcribed cDNAs, subcloned and sequenced (10 clones were routinely sequenced). The PKC alpha point mutation at position 908 of the cDNA sequence was found in four out of the nine adenomas and in the follicular carcinoma. It was neither detected in the papillary carcinomas nor in the adjacent normal tissues (one was the adjacent normal tissue of the follicular carcinoma; in this sample, genomic DNA and cDNA were used to look for the presence of the mutant), demonstrating the somatic nature of this mutant. Western blot analysis of PKC isoforms showed that the expression of all isoforms was higher in the thyroid neoplasms as compared with their adjacent normal tissue (n = 3). It was also higher in the samples containing the PKC mutant (two follicular adenomas, two colloid adenomas and the follicular carcinoma) as compared with the tumors where it was not detected (three papillary carcinomas and five adenomas). Samples could be ordered according to their increasing PKC expression as follows: normal adjacent tissue < follicular adenomas without PKC alpha mutant < or = papillary carcinoma < follicular adenomas with PKC mutant < follicular carcinoma with PKC mutant. In conclusion, the discovery of the PKC alpha mutant in thyroid neoplasms demonstrates that this mutant is not particular to human pituitary tumors where it was originally detected. It is a somatic mutation and its presence is concomitant with high levels of all of the PKC isoforms analysed. The presence of the PKC mutant in thyroid neoplasms raises the question of its importance in thyroid tumorigenesis.

Adenocarcinoma, Follicular↗

PubMed1992

Thyroid hormone generalized resistance.

The syndromes of thyroid hormone resistance may affect overall or only some tissues. The generalized resistance is an inherited disease which involves a familial eumetabolic or hypometabolic goiter, increased free thyroid hormones with normal or elevated plasma TSH levels; children may present mental retardation, deafness, short stature and delayed bone age. The disease is frequently misdiagnosed. In vivo and in vitro tests may be used to assess the diagnosis. The defect of increment of sex hormone-binding globulin after administration of T3 may be useful in the demonstration of the disease. Therapy uses high T4 or T3 doses in hypometabolic patients. The generalized thyroid hormone resistance could be linked to abnormalities at the T3 receptor and c-erb A gene level, as a consequence of different point mutations or deletions involving the hormone-binding domain.

Drug Resistance↗