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Biomedical subjects

J Tourniaire

Publications and source records attributed to J Tourniaire.

At least 37 records · Page 2Linked to original sources
PubMed1992

Decreased hypoglycemic effect of insulin at night in insulin-dependent diabetes mellitus and healthy subjects.

Diurnal variations in insulin-induced hypoglycemia and in plasma counterregulatory hormone concentrations were explored in eight insulin-dependent diabetic and six healthy subjects during a 100-min iv insulin infusion performed at 0300 h and 1500 h. In healthy subjects, plasma glucose concentrations (mean +/- SD) fell by 35 +/- 2% during the daytime test and by 26.5 +/- 2% during the nocturnal test (P less than 0.01). Plasma cortisol, GH, and epinephrine concentrations increased more during the daytime than during the nocturnal test. In contrast, plasma glucagon concentrations rose more during the nocturnal tests. In insulin-dependent diabetes mellitus patients, insulin infusion had to be interrupted in three subjects because plasma glucose fell below 1.9 mmol/L 80 min after the beginning of the test. In the other five patients plasma glucose fell by 34 +/- 5% during the daytime test while no significant decrease in plasma glucose was observed in any of the eight patients during the nighttime test. Counterregulatory hormone concentrations were consistent with the results of plasma glucose, with no change during the nocturnal test and significant increases in cortisol, GH, and epinephrine during the daytime test. These results show that insulin sensitivity is decreased at night in comparison to midafternoon in healthy subjects and that in insulin-dependent diabetes mellitus patients this phenomenon is exaggerated, even in patients with defective counterregulation to hypoglycemia.

Adult↗
PubMed1991

[Gonadotropic pituitary adenoma and pregnancy. Value of bromocriptine].

The authors report a case of pituitary adenoma with positive immunospecific staining for beta-FSH and serum alpha subunit. The tumour was revealed by an amenorrhoea-galactorrhoea syndrome with hyperprolactinaemia and without increase in serum gonadotrophin values. Pregnancy occurred during bromocriptine treatment which made it possible to control an hemianopsia developed in the fourth month of gestation. The adenoma was successfully removed a few months later.

Adenoma↗
PubMed1991

Pathophysiology of sex hormone binding globulin (SHBG): relation to insulin.

In humans, the plasma level of sex hormone binding globulin (SHBG) is regulated by several hormones. We have now accumulated evidence that SHBG is also intimately related to nutritional state. However, we do not yet know what specific signal, if any, may be the regulator of SHBG. There is a strong and negative correlation between fasting insulin level and SHBG in obese as in hyperandrogenic women. Under such circumstances, a high fasting insulin level, normal glycemia and a low SHBG level suggest insulin resistance in terms of glucose disposal but not in terms of SHBG inhibition. This is a rather complex situation. It is too early to judge the importance of IGF-I in the regulation of SHBG. But it may turn out that IGF-I is the main regulator of SHBG and that, by interaction with the IGF-I receptors, insulin carries on its inhibitory activity on SHBG.

Adipose Tissue↗
PubMed1991

Somatotropic adenomas without acromegaly.

Seventeen somatotropic adenomas removed from patients without acromegaly were studied. Thirteen of them presented as a prolactinoma with amenorrhea and/or galactorrhea and elevated serum PRL levels. According to basal serum GH levels, the patients were divided into two groups, namely Group I: GH slightly elevated (n = 4) and group II: GH less than or equal to 5 micrograms/l (n = 13). The tumoral GH secretion was proved by immunocytochemistry in all cases and by intratumoral RIA, in vitro study and/or in situ hybridization in five of them. Pathological, clinical and biochemical relationships suggested two anatomoclinical aspects. In group I, the tumors were small, well-differentiated somatotropic adenomas with clinically silent GH hypersecretion. It is probably an early stage of the disease. In group II, the tumors were large with normal GH serum levels. They were poorly differentiated and secreted very low amounts of GH. In nine of them, PRL and/or PRL mRNA expression were also detected. These tumors do not secrete enough GH to increase serum levels and cause acromegaly. The somatotropic adenomas without acromegaly correspond to two anatomoclinical aspects of the disease.

Acromegaly↗
PubMed1991

Glucocorticoid receptors in lymphocytes in anorexia nervosa.

OBJECTIVE: The aim was to explore the down-regulation of the glucocorticoid receptors during hypercortisolaemia in anorexia nervosa. DESIGN: Urine and plasma samples were obtained for cortisol determination and blood lymphocytes were isolated for receptor binding studies. PATIENTS: Sixteen anorexic patients, aged 16-27 years, with a mean +/- SEM body mass index of 14.2 +/- 2.0 (ranging from 11.1 to 17.4), and 15 normal women were studied. Six patients were reinvestigated after a significant weight gain. MEASUREMENTS: The binding capacity and affinity of the glucocorticoid receptors were measured with dexamethasone as ligand on lymphocytes. RESULTS: In patients, both total and free plasma cortisol concentrations were higher than in the normal women, as was their urinary free cortisol; the number of glucocorticoid receptors per cell (Ro) and the binding affinity (Kd) for dexamethasone were, however, not significantly different (Ro: 7687 +/- 1750 vs 7347 +/- 1285 sites/cell; Kd: 7.7 +/- 2.4 vs 7.4 +/- 1.7 nM at 24 degrees C). After weight gain (14 +/- 2 to 16 +/- 2 kg/m2), receptor numbers were 8421 +/- 2126 (pre) and 9011 +/- 500 (post) sites/cell, which are not significantly different (P greater than 0.2); the Kd was unchanged (9.3 +/- 2.6 vs 9.2 +/- 2.4 nM). CONCLUSIONS Hypercortisolaemia does not down-regulate the lymphocyte glucocorticoid receptors in anorexia nervosa and a post-receptor defect might be involved in peripheral tissue resistance to the effects of glucocorticoid hormones in undernutrition.

Adolescent↗
PubMed1991

[Inverse relationship between body mass index and fasting insulinemia with testosterone-binding protein in hirsutism].

To identify the factor(s) involved in the decreased of sex steroid binding-protein (SBP) in hirsute women, we have investigated which parameters were in correlation with SBP in a population of 90 hirsute women. We found no significant correlation of SBP binding capacity with the plasma concentrations of the main androgens. Conversely, SBP was in inverse and significant correlation with body mass index and with the fasting insulin plasma level. These findings confirm that nutritional status must be considered in the physiopathology of hyperandrogenism in women. The control of overweight may be a goal for treating hirsutism in some patients.

Androgen-Binding Protein↗
PubMed1991

[Ehlers-Danlos syndrome and pregnancy. Apropos of a case].

Ehlers-Danlos Syndrome is a hereditary dysplasia of connective tissue with an abnormality in collagen synthesis. The syndrome consists of increased elasticity and fragility of the skin, increased laxity of the ligaments of the joints and fragility of the blood vessels. It is rarely associated with pregnancy but when it is several problems arise which are demonstrated in our case. Our patient had a type III syndrome (hypermobility of the joints) or a type IV syndrome (echymoses, Sack-Barabas Syndrome). In the literature the following are reported: premature rupture of the membranes with premature delivery, tears, perineal haematomas and type IV ruptures of the great vessels of the uterus. The best way of delivering and anaesthetising the patient are discussed. The prognosis depends above all on the type of the disease (25% of mothers die in type IV disease). Strict rest and Pfannestiel lower segment Caesarean section operation under general anaesthetic allowed us to achieve a favorable outcome for the mother and for her child.

Adult↗
PubMed1990

[Treatment of hirsutism with spironolactone and progestagen combination].

The antiandrogenic activity of spironolactone was used for treating hirsutism in 76 women, 29 of whom also had acne. Midcycle vaginal bleeding was observed in 21 patients under spironolactone 75 mg per day. This side-effect disappeared after a progestagen administered 10 days each month was added to the treatment. With this combination, spironolactone was well tolerated and effective in treating acne within the first months of administration, but in 61 percent of the patients at least 6 months were required to improve hirsutism.

Acne Vulgaris↗
PubMed1990

[Microalbuminuria and diabetic nephropathy. Detection and correlation with other degenerative complications].

The prevalence of microalbuminuria and persistent proteinuria was studied in a population of 801 diabetic patients (535 with type II and 266 with type I diabetes). Urinary albumin excretion rate (AER) was measured on morning samples by laser nephelometry. Normoalbuminuria, as defined, in the absence of contaminated urine, by an albumin: creatinine (A/C) ratio below 2, was found in 551 patients, microalbuminuria (NC greater than or equal to 2 with AER below 200 mg/l) in 190 patients and persistent proteinuria (AER greater than or equal to 200 mg/l) in 60 patients. Microalbuminuria was present in 48 (18 p. 100) IDDM patients and 142 NIDDM patients. In IDDM patients, AER increased with the duration of the disease with no apparent influence of age at the onset. The prevalence of hypertension was 25 p. 100 and 61 p. 100 in IDDM patients with microalbuminuria and macroproteinuria respectively versus 10 p. 100 in patients with normoalbuminuria. This prevalence increased in NIDDM patients from 39.3 p. 100 with normoalbuminuria to 40.8 p. 100 and 76.2 p. 100 with microalbuminuria or macroproteinuria respectively. Proliferative retinopathy in type I and type II patients with normal AER was 7.4 p. 100 and 1.2 p. 100 respectively increasing to 15.2 p. 100 and 8.9 p. 100 with microalbuminuria and 27.8 p. 100 and 23.1 p. 100 with macroproteinuria. The prevalence of coronary disease increased from 4 to 10.4 p. 100 in patients with type I diabetes and microalbuminuria. The prevalence of cardiac failure increased from 1.5 to 2.1 p. 100 in type I diabetics and from 3.2 to 7.8 p. 100 in type II diabetics in the presence of microalbuminuria. Patients with microalbuminuria had increased levels of glycosylated hemoglobin A 1C but statistical difference was only obtained for patients with type II diabetes. Routine analysis of AER in diabetics allows early detection of diabetic nephropathy and emphasizes the need for tight metabolic and blood pressure control. Hypertension can be detrimental to nephropathy but might also initiate renal lesions in NIDDM patients.

Adult↗
PubMed1990

[C-peptide assays of the urine and plasma at baseline and under stimulation with glucagon in healthy subjects and diabetics].

Urinary (CPU) and plasma C peptide values at baseline (CP0) and under stimulation with glucagon were determined in healthy subjects (n = 17) and in insulin-dependent (IDD, n = 45) and non insulin-dependent (NIDD, n = 32) diabetics. A significant difference in the parameters of insulin secretion (x? SD) was found on the one hand between the IDD group (CPU = 5.58 +/- 5.58 nmol/24 h; CP = 0.14 +/- 0.08 nmol/l; maximum C peptide value after stimulation (CPmax) = 0.33 +/- 0.31 nmol/l; C peptide delta (delta CP) = 0.14 +/- 0.14 nmol/l; area under the curve (A) = 5.00 +/- 4.84) and the NIDD group (CPU = 15.47 +/- 8.22 nmol/24 h; CP = 0.64 +/- 0.28 nmol/l; CPmax = 1.14 +/- 0.44 nmol/l; delta CP = 0.50 +/- 0.31 nmol/l; A = 17.5 +/- 5.86) and on the other hand between the IDD group and the control group (CPU = 18.20 +/- 8.40 nmol/24 h; CP = 0.41 +/- 0.11 nmol/l; CPmax = 1.00 +/- 0.31 nmol/l; delta CP = 0.69 +/- 0.20 nmol/l; A = 17.10 +/- 4.45). As regards the NIDD group, only the fasting C peptide and delta C peptide values were significantly different from those found in the control group. The significance of each parameter of insulin secretion was also studied. There was a correlation between the values of C peptidaemia before and after stimulation with glucagon. However, the correlation between plasma C peptide and urinary C peptide values was mediocre, probably because of the numerous variability factors which intervene in the urinary excretion of C peptide.

Adult↗
PubMed1990

Rapid escape of cortisol from suppression in response to i.v. dexamethasone in anorexia nervosa.

The suppressive effect of dexamethasone (Dex) on plasma cortisol and beta-lipotrophin (beta LPH) was investigated in patients with anorexia nervosa. Dex was given either orally, 1 mg at 2400 h, with blood sampling at 0800 h on the days before and after Dex, or by i.v. infusion starting at 1100 h (1 mg/h) for 4 h with sampling at 0800, 1100, 1500, 2000 and 2400 h and at 0800 h the following day. The plasma cortisol and beta LPH levels during oral or i.v. Dex administration were compared between patients and normally menstruating women of normal weight. The results showed that Dex administration depressed cortisol significantly (P less than 0.0001) during oral or i.v. infusion in most patients, without, however, suppressing it entirely as is the case in normal women. Moreover, during i.v. Dex infusion, the concentrations of cortisol escaped suppression and were higher than in normal women (less than 50 nmol/l) by 0800 h on the day following infusion. In the patients who were reinvestigated after re-feeding and weight gain (n = 9), a normal suppression of cortisol in response to i.v. Dex infusion was observed in only five cases and a slight failure to suppress, although concentrations were lower than before refeeding, was still evident in four. We concluded that, in anorexia nervosa, cortisol concentration rapidly escapes suppression by Dex administration, and that this escape is not related to the degree of starvation.

Administration, Oral↗
PubMed1990

Measuring vibration sensations with graduated tuning fork. Simple and reliable means to detect diabetic patients at risk of neuropathic foot ulceration.

To find a simple and reliable means to measure vibration sensations, 189 diabetic patients and 88 control subjects were tested at different sites with a graduated tuning fork. Within-test variation at big toes reached 8.4% in diabetic patients vs. 2.2% in control subjects. Mean contralateral variation was 7.5% in diabetic patients vs. 2.5% in control subjects. Tuning-fork sensations were inversely correlated with duration of diabetes, whereas no correlation was found with HBA1c levels or the severity of retinopathy. Ninety-nine (52%) patients had vibratory sensation at big toes of less than 99th percentile of normal values for age. In addition, 51% of the patients with clinical symptoms at extremities (n = 67), 70% of the patients without tendon reflexes (n = 50), and 75% of the patients with abnormal nerve conduction velocities (n = 60) also had low vibration sensations. All patients with lower-limb injuries (n = 7) had values at big toes of less than 2. Altogether, the graduated tuning fork represents a simple and reliable alternative to quantitate vibration sensations. Long-term follow-up of asymptomatic patients will indicate whether these abnormalities reflect underlying neuropathy. Patients with abnormal values at screening will necessitate additional investigations and special foot-care education programs.

Adolescent↗