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Biomedical subjects

P Garnier

Publications and source records attributed to P Garnier.

At least 91 records · Page 5Linked to original sources
PubMed1985

Correlative studies between the presence of thyrotropin-releasing hormone (TRH) receptors and the in vitro stimulation of growth-hormone (GH) secretion in human GH-secreting adenomas.

Specific receptors for TRH were characterized on cellular membranes of 6 out of 13 somatotrophic adenomas obtained from acromegalic patients. These receptors had the same dissociation constant (Kd: 62 +/- 10 nM) as those found in human PRL-secreting adenomas, but their maximal number of binding sites (Bmax: 76 +/- 24 fmol/mg of protein) was six fold smaller. A good correlation was found between the presence of TRH receptors and the in vitro TRH-induced stimulation of GH secretion. The increase in GH release varied from 25 to 200%. It was thus concluded that these receptors are functional. However, why only some of the human somatotrophic adenomas possess TRH receptors and respond to TRH in vitro needs further investigations.

Adenoma↗
PubMed1985

Effects of gonadotrophin-induced elevation of serum testosterone upon somatomedin C levels and serum thymidine activity in children.

3H-thymidine uptake into lectin-activated human lymphocytes allows to measure a growth-stimulating activity of serum, the thymidine activity (TA), which is GH dependent in vivo and related to somatomedins (Sm). In this work, it is shown: that addition of human chorionic gonadotrophin (HCG) or testosterone in vitro does not increase the 3H-thymidine uptake into lymphocytes; that the gonadotrophin-induced elevation of testosterone in children is accompanied by a significant increase of TA and, at a lesser degree, of Sm C; that these two increases are significantly correlated, and that the age-related variation of TA and Sm C after HCG stimulation test are not parallel.

Adolescent↗
PubMed1985

Interaction between somatostatin and TRH on growth hormone secretion in perifused human growth hormone tumor cells.

The interaction between somatostatin (SRIF) and thyrotropin-releasing hormone (TRH) on growth hormone (GH) release has been studied on dispersed somatotrophic tumor cells obtained from 7 acromegalic patients. TRH increased GH secretion in 4 cases and SRIF decreased GH secretion in 5 cases. When TRH and SRIF were concomitantly perifused, SRIF, when active by itself, prevented and reversed the TRH-induced stimulation of GH release, while TRH never antagonized the inhibitory effect of SRIF. We conclude that, in these adenomatous cells, the physiological inhibitory factor (SRIF) overcomes the nonphysiological stimulatory factor (TRH) in the control of GH secretion.

Acromegaly↗
PubMed1984

Studies in constitutionally tall adolescents. II. Effects of bromocriptine on growth hormone secretion and adult height prediction.

After previous demonstration of paradoxical GH responses to TRH and oral glucose loading tests in some constitutionally tall adolescents, we studied the effects of a small dose of bromocriptine (5 mg/day) on GH secretion and adult height prediction. In 10 patients, each of whom had a substantial plasma GH increase after TRH injection, bromocriptine reduced or suppressed this abnormal response. In 4 of these patients who also had paradoxical GH increases after glucose loading, bromocriptine suppressed this abnormality in 2. Predicted adult height was reduced in 10 of the 12 patients after 6-12 months of treatment. This reduction resulted either from a decrease in growth velocity, an increase in skeletal maturation rate, or both. Since no side effects were noticed we suggest that bromocriptine may be a valuable alternative to sex steroid treatment to limit final height in excessively tall adolescents.

Adolescent↗
PubMed1984

[Racket-shaped tubal-uterine anastomosis. Technic and results].

Proximal tubal lesions that are discovered when a case of sterility is being worked out are polymorphic in nature and they are variable in extent. Fortunately it is rare that a proximal tubal lesion should involve the whole interstitial portion and the uterine os of the tube. This is why many surgeons have taken up the method of tubo-uterine implantation advocated by Palmer. Salat-Baroux and Cornier published a paper on microsurgical tubo-interine implantation in 1979. We since 1978 have been carrying out a technique of tubo-uterine anastomosis in raquette shape (mostly isthmo-uterine). This is described in detail in this article. The first results on 32 anastomose carried out in 23 patients who were operated on of whom 17 cases had pure cornual lesions and 6 cases bipolar lesions seem to be encouraging with a patency rate 6 months later of 69% and a rate of intra-uterine pregnancy of 23.2% (0.10-0.41) at 12-18 months and 31.1% (0.14-0.56) at 18-24 months (using an actuarial method). Up to now we have not had an extra-uterine pregnancy near the site of suture. Our technique seems to us to give a worthwhile alternative microsurgical method to implantation in interstitial lesions that are widespread and deep.

Actuarial Analysis↗
PubMed1984

[Should one operate on bifocal tubal lesions in 1984? Apropos of 54 cases].

We have analysed 54 cases where the patients had two lesions in the tubes and were treated with microsurgery. The results of histological examinations show that chronic salpingitis in the major lesion. Infection was the aetiological cause in 76% of the cases. The results of microsurgical treatment are poor with a low rate of intra-uterine pregnancy: [19.4% (0.08-0.42) at 24-30 months for pregnancies that were continuing and for abortions, 11.7% (0.04-0.33) at 24-30 months using actuarial techniques for estimating pregnancies that were continuing]. There was a high risk of extra-uterine pregnancy [35% (0.18-0.58) at 24-30 months]. These results make us wonder whether microsurgery or in vitro fertilisation should be the treatment of preference in these cases where the tubes are affected in two areas.

Actuarial Analysis↗
PubMed1983

Growth hormone response to thyrotropin-releasing hormone and oral glucose-loading tests in tall children and adolescents.

The effects of TRH and oral glucose loading on the release of GH were investigated in 10 children or adolescents with constitutional tall stature. Eight of these children had a family history of above average height. The mean (and SEM) baseline GH levels (3.12 +/- 2.0 ng/ml) were similar to those in control subjects. Somatomedin activity, measured by sulfate incorporation into chick embryo cartilage, was elevated. Oral glucose loading caused an early significant increase in plasma GH at 30 min in 2 of these subjects and a late rise at 180 min in 4 others. Intravenous injection of synthetic TRH (0.2 mg/m2) caused a marked increase in plasma GH (17 +/- 3.0 ng/ml) in 7 of the 10 patients; the peak of GH was observed within the first hour after the injection of TRH in 3 cases, while a later peak was observed in the second hour after injection in 4 others. Peak plasma PRL (47 +/- 3.8 ng/ml) and TSH (20 +/- 1.2 microU/ml) levels in response to TRH were normal. These results suggest a disorder of hypothalamo-pituitary regulation of GH secretion in certain children with apparently constitutional tall stature. Similar findings in a probably preacromegalic girl are reported.

Administration, Oral↗
PubMed1980

A possible relationship between serum transferrin, growth hormone secretion and height velocity in children.

Since transferrin (Tf) in vitro has a growth-promoting activity and is associated with NSILA properties, the aim of this work was to study in vivo the relationships between Tf, somatomedin activity (SM), growth hormone (GH) secretion, and height velocity in children. An iv infusion of ornithine hydrochloride was given to 23 controls; the induced rise of GH was accompanied by a simultaneous fall of SM (r = -0.711, P less than 0.001) and was preceded by a fall of Tf (r = -0.610, P less than 0.01). In 17 obese children SM was within the normal range, when Tf levels were higher and arginine-induced GH peaks lower than in the controls, and a negative correlation was found between Tf basal levels and GH peaks (r = -0.608, P less than 0.01). In 9 children with confirmed hypopituitarism the Tf levels were significantly lower than in the controls. In 14 children with confirmed or suspected hypopituitarism a single im injection of hGH (6 mg) failed to induce Tf variations over 24 h. In 39 of these children the height velocity was significantly correlated with Tf basal levels (r = 0.701, P less than 0.001). These data suggest that transferrin is involved in growth regulation, and that GH secretion is related to transferrin levels by a feed-back mechanism.

Adolescent↗
PubMed1980

[Transferrin, somatomedins and growth].

Plasma transferrin is significantly positively correlated to the growth velocity in normal children and children with various growth disorders. In hypopituitary dwarfs, both plasma transferrin and somatomedin are significantly lower than in controls. Acute variations of the plasma transferrin levels could be involved in the regulation of the GH secretion by a feedback mechanism. Yet, transferrin is neither a somatomedin or a somatomedin-binding protein, and the mechanisms relating growth to transferrin remain unknown.

Adolescent↗
PubMed1979

Biological apatite crystal disolution.

The dissolution curves of human acid-treated enamel powder are characterized by a rapid initial step followed, after 10 or 15 minutes, by a second stage, with release of very small amounts of calcium. Increase in pH and addition of fluoride ions tend to diminish, for short intervals, the amount of dissolved apatites. For higher pH values the decrease is noted over a longer time. Study of the relative ionic variation of human enamel powder from young and adult patients subjected to acid requires infra-red vibration band analyses. Special attention was given to the absorptions at 610 cm-1 (phosphate groups), 880 cm-1 (CO32- in OH- sites and HPO42-), 1410 cm-1 (CO32- in phosphate sites) and 1550 cm-1 (CO32- in OH- position). All results were related to vibration band at 610 cm-1. A preferential loss of carbonates in the two possible sites was always observed for 10 or 15 minutes, followed by a high release of phosphate. The increase of pH or small amounts of fluoride displaced the preferential carbonate loss to longer times. In the presence of higher fluoride levels a disappearance of the preferential loss of carbonates was noted. A continuous increase of HPO42- in the absence of fluoride occurred; however a straight line with a smaller shape was present, with fluoride addition.

Apatites↗