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Biomedical subjects

P Fossati

Publications and source records attributed to P Fossati.

At least 55 records · Page 3Linked to original sources
PubMed1989

Experience of a six-month treatment with sandostatin at increasing doses in acromegaly.

The French Sandostatin/Acromegaly Study Group performed a multicentric, prospective, open-label trial of incremental doses with the aim of obtaining the best antisecretory effect. Forty-two patients (24 women, 18 men) aged 22-71 years were involved, either after unsuccessful surgery and/or radiotherapy (30 patients), or as primary treatment (12 patients). Doses were increased from 3 x 100 to 3 x 500 micrograms/day, according to the results of hormonal investigations (GH profiles and Sm-C) performed each month and for each dose, and tolerability. Four patients dropped out because of major digestive troubles. Recurrent pain at the injection site and minor gastrointestinal disorders were noted in some patients. Asymptomatic gallstones appeared in 4 patients. Carbohydrate tolerance and insulin secretion (determined by diurnal plasma glucose and insulin profiles) were not significantly altered by the various SMS doses. Clinical improvement was determined by the scoring of the symptoms. Mean plasma GH concentrations were significantly reduced for each SMS dose, compared to pretreatment values. Fifteen patients obtained 75% of GH values less than or equal to 2 micrograms/l. In 9 patients the highest dose failed to bring GH below 10 micrograms/l. Sm-C normalized in 17/31 patients. After 6 months of treatment a tumor reduction of 20-50% was found in 7 patients and greater than 50% in 5 patients. We conclude that (1) the tolerability of SMS is compatible with long-term treatments; (2) clinical improvement and biological criteria of efficacy are obtained in 3/4 acromegalic patients treated by SMS, and that (3) some patients are resistant to SMS and the increase in the dose does not improve the result.

Acromegaly↗
PubMed1989

Adrenocorticotropin and cortisol responses to ovine corticotropin-releasing factor in alcohol dependence disorder. Preliminary report.

A 100-micrograms bolus of synthetic ovine corticotropin-releasing factor was administered intravenously to 10 nondepressed inpatients suffering from an alcohol dependence disorder. The test was performed during withdrawal and after 4 weeks of abstinence. During withdrawal, the plasma cortisol responses of alcoholic patients and 7 control subjects were similar, except for an earlier decrease of cortisol in the former group. However, after 4 weeks of abstinence, the cortisol response was significantly lower in alcoholic patients than in controls. These abnormalities observed during discontinuance of alcohol consumption may reflect adaptive mechanisms of the hypothalamic-pituitary-adrenal activity which may be previously altered by chronic alcohol intoxication.

Adrenal Cortex↗
PubMed1989

Enzymatic assay of magnesium through glucokinase activation.

We describe an improved enzymatic method for assaying magnesium in serum, plasma, or urine. Magnesium participates as an Mg.ATP complex in a reaction catalyzed by glucokinase (EC 2.7.1.2) coupled to an NADP+-dependent glucose-6-phosphate dehydrogenase (EC 1.1.1.49) reaction. The increase of absorbance at 340 nm, due to the NADPH produced, is proportional to the amount of the activated glucokinase, which in turn is related to the concentration of magnesium in the sample. The method is characterized by a zero-order reaction kinetics, affording a simple and rapid assay with good sensitivity and linearity (up to 2.06 mmol/L) and by working solutions that are stable (refrigerated) for one month. The method is reliable, produces test results that compare closely with those of the atomic absorption spectrophotometry (r greater than or equal to 0.99), is suitable for routine work, and lends itself to automation.

Drug Stability↗
PubMed1989

One-step protocol for assays of total and direct bilirubin with stable combined reagents.

We describe an improved colorimetric method for assays of total and direct bilirubin in serum. Bilirubin reacts with diazotized sulfanilic acid in an acidic medium to form a blue azopigment. Total bilirubin is assayed in the presence of reaction accelerators (caffeine, urea, and citric acid), direct bilirubin in their absence. The azo compound so formed is read at the same wavelength (570 nm) in both assays. A sample blank is run in parallel. Standard curves are linear for total and direct bilirubin concentrations up to 513.0 and 256.5 mumol/L, respectively. The method is characterized by (a) use of the same protocol for both assays, i.e., a one-step procedure with short reaction time (5 min at room temperature), and (b) use of a single working solution, which, refrigerated, is stable for one month. The method is reliable, yields results that compare closely with those of the classical Jendrassik--Gróf method, is suitable for routine use, and lends itself to automation.

Bilirubin↗
PubMed1988

Screening heterozygotes for 21-hydroxylase deficiency among hirsute women: lack of utility of the adrenocorticotropin hormone test.

Heterozygosity for 21-hydroxylase deficiency (21-OHD) was investigated in 174 adult hirsute women by using the sum of the incremental responses of serum 17 alpha-hydroxyprogesterone (17 alpha-OHP) and progesterone (P) (delta 17 alpha-OHP + P), 60 minutes after a 0.25 mg intravenous (IV) bolus of synthetic adrenocorticotropic hormone (ACTH). The distribution of 17 alpha-OHP + P in hirsute women was bimodal, allowing two subgroups to be distinguished. In one subgroup including 137 patients, the mode was similar to controls and all values were lower than 3 ng/ml. Thirty-seven (21%) patients constituted another subgroup with values higher than 3 ng/ml and could a priori have been considered as heterozygotes for 21-OHD. However, human leukocyte antigen genotyping provided no conclusive evidence that this subgroup included exclusively heterozygotes for the 21-OHD.

17-alpha-Hydroxyprogesterone↗
PubMed1988

Recovery of ovulatory menstrual cycles under hydrocortisone in two amenorrheic women with isolated corticotropin deficiency.

Two amenorrheic women presenting clinical signs of adrenal insufficiency were shown to have isolated corticotropin deficiency (ICD). LH and FSH were normally responsive to GnRH. The occurrence of this disease during the postpartum and the presence of autoantibodies against corticotropic cells in one case may indicate that ICD was a sequela of an autoimmune hypophysitis. The presence of amenorrhea, while the gonadotroph was not damaged, and the reappearance of ovulatory menstrual cycles under the sole effect of hydrocortisone replacement therapy suggest that cortisol deficiency may by itself alter the gonadal function.

Adrenal Insufficiency↗
PubMed1988

Enzymatic colorimetric method for the determination of inorganic phosphorus in serum and urine.

The performance of an enzymatic colorimetric method for the determination of inorganic phosphorus in serum and urine is described. Phosphate ions react with inosine in the presence of purine nucleoside phosphorylase to form hypoxanthine; this is oxidized by xanthine oxidase to uric acid with production of hydrogen peroxide. The latter is determined with the aid of the chromogen system peroxidase/4-aminophenazone/N-ethyl-N-(3-methylphenyl)-N'-acetylethyl enediamine , the coloured product being measured at 555 nm. This series of reactions is completed in 5 min at 37 degrees C. The test is linear up to 240 mg/l. Analytical recovery in serum averaged 101.2 +/- 1.2% and in urine 101.9 +/- 3.2%. Within-run and between-run precision studies in serum and urine samples gave CVs less than or equal to 4.54% (at 22.0 mg/l). Results obtained by this method agree (r = greater than or equal to 0.983) with the molybdate UV and molybdenum blue methods. Interference by endogenous substances, including organic phosphate, was negligible.

Colorimetry↗
PubMed1988

[Selective control of different hypophysial secretions by long-lasting pharmacodynamic agents. Analogs of somatostatin and LHRH and long-lasting bromocriptine].

The biological activity of the natural somatostatin can be quantitatively and qualitatively altered by the substitution and/or the exclusion of some of its amino-acids. The most used synthetic analog, SMS 201-995, has a potent inhibiting effect on GH secretion, but is less effective on insulin and glucagon secretions. It is mainly used in Endocrinology for the treatment of acromegaly. It is also useful for inhibiting the inappropriate TSH secretion from a thyrotroph adenoma. The LH-RH agonists ast essentially by desensitizing the gonadotroph from the endogenous LH-RH. By sub-cutaneous, intra-muscular or nasal route, they allow to inhibit the gonadal functions in some hormone-dependent cancers and in true precocious puberty. More recently, they have been tested for the treatment of gonadotropic adenomas, where they may have sometimes a paradoxical effect. In combination with exogenous gonadotropins, they enhance the control of ovulation and are new valuable tools for IVF programs. Clinical studies with the LH-RH antagonists are just beginning. The long-acting bromocriptine affords a new alternative to the oral treatment of hyperprolactinaemia. Its suppressive effects lasts at least 35 days in normal subjects and 21 days in patients with macroprolactinomas.

Bromocriptine↗
PubMed1987

Evidence for an increased glycation of IgG in diabetic patients.

The levels of non-enzymatically glycated total plasma proteins, albumin and IgG were determined in diabetic and non-diabetic patients using affinity chromatography on boronate-agarose gels. A significant increase in both glycated albumin and IgG, and in total glycated plasma proteins was demonstrated. A good correlation between glycated albumin and glycated hemoglobin was observed, while the correlation between glycated IgG and glycated albumin (or hemoglobin) was lower. This was found probably related to wide variations of glycated IgG for diabetics patients who have high glycated hemoglobin levels. These variations were inversely correlated with total serum IgG. Determination of fructosamine or 5-hydroxymethylfurfural content of IgG showed a significant increase in diabetics. Glycated IgG was found to contain approximately one mole of glucose. The main site of glycation was determined to be present in the Fab (more precisely the Fd) part of the IgG molecule.

Blood Glucose↗
PubMed1987

[Mechanisms of diabetic impotence. 25 cases].

Twenty-five impotent diatetics were investigated by means of nocturnal penile tumescence monitoring, hormone determinations, penile blood pressure measurement, artificial erection test and dynamic cavernosography, bulbocavernous reflex latency time measurement and cortical evoked responses from pudendal nerves. Sexological treatment was then attempted for a better evaluation of the psychogenic element. Penile blood pressure was also measured in 15 non-impotent diabetics and was found to be abnormal as often as in impotent diabetics. The results as a whole demonstrated that impotence was predominantly psychogenic in 9 cases, predominantly organic in 12 cases and mixed psychogenic and organic in 4 cases. Diabetic impotence is often due to several causative factors, as was the case in 12 of our patients. The factors most frequently responsible were psychological (present in 13 cases), neurological (present in 12 cases) and vascular factors (arterial abnormalities in 7 cases, "venous leakage" in 4 cases). Endocrine abnormalities were observed in only 2 cases.

Diabetes Complications↗
PubMed1987

Insulin and HDL-cholesterol metabolism.

Insulin is essential to the physiological regulation of high density lipoprotein (HDL) cholesterol metabolism. It acts directly at the hepatic level by favouring HDL2 to HDL3 conversion (by its action on hepatic lipase). In the peripheral circulation, it induces HDL2 formation by allowing triglyceride-rich lipoprotein catabolism by lipoprotein lipase (LPL) and free cholesterol esterification by lecithin acyl cholesterol transferase (LCAT). In the case of insulin deficiency or peripheral insulin resistance, there is a reduction of HDL cholesterol related to HDL2 decrease, partly due to LPL deficiency. In the case of endogenous hyperinsulinism, there is an intrahepatic disturbance of HDL metabolism partly related to excessive synthesis of VLDL-TG and leading to the decrease of HDL2/HDL3 and enhanced formation of HDL2 TG. When hepatic hyperinsulinism is associated with peripheral insulin resistance, HDL cholesterol decrease is the consequence of both intrahepatic action of insulin and diminution of its peripheric action. Optimized insulin therapy can normalize HDL cholesterol in case of true insulin deficiency. When there is preservation of insulin secretion, HDL cholesterol remains lower than controls. Insulinopenia as well as hyperinsulinism can favour atherogenic lipoprotein disturbances.

Child↗
PubMed1986

A double blind controlled study of the hormonal and clinical effects of bromocriptine in the polycystic ovary syndrome.

Previous studies on the efficacy of bromocriptine for the treatment of patients with the polycystic ovary syndrome failed to include control groups. This study, therefore, was undertaken to determine the clinical and endocrine effects of bromocriptine and a placebo (given in a random double blind fashion) in 55 patients with PCOS. The plasma levels of estrone, estradiol, testosterone, androstenedione, dehydroepiandrosterone, dehydroepiandrosterone sulfate, 17-hydroxyprogesterone, and serum PRL and gonadotropins (LH and FSH) were measured before treatment. In addition the serum PRL response to TRH and the serum LH and FSH response to GnRH were determined. The effects of acute administration of bromocriptine (2 X 2.5 mg at 12-h intervals) on serum gonadotropins and their response to GnRH were studied to explore the possibility that this test might predict the response to chronic bromocriptine treatment. Bromocriptine then was given at an initial dose of 1.25 mg twice daily. If no clinical improvement occurred 2.5 mg were given twice daily for at least 6 months. Hormonal measurements and dynamic tests were repeated after 3 and 6 months of therapy. The endocrine profile of the two groups was not different before treatment. The clinical results were not better in the treatment group than in the placebo-treated patients: therapy was successful (restoration of ovulatory cycles of less than 35 days duration) in 12 of 28 patients taking bromocriptine vs. 8 of 27 taking placebo. Slight improvement (1 or 2 ovulations) occurred in 3 of 28 vs. 3 of 27, and failure (no clinical change) in 13 of 28 taking bromocriptine vs. 16 of 27 taking placebo, respectively. Serum PRL fell significantly in the bromocriptine group, and there was a significant fall in the serum LH response to GnRH in both groups. No hormonal measurement or response predicted the clinical response to treatment. The only significant effect of chronic bromocriptine therapy (5 mg/day) in patients with the polycystic ovary syndrome was to lower the serum PRL concentration.

Adolescent↗
PubMed1986

Clinical and biological phenotypes in late-onset 21-hydroxylase deficiency.

We analyzed data from 20 patients with late-onset 21-hydroxylase deficiency (LOHD). Three clinical phenotypes could be distinguished among the 18 women. Seven (39%) presented with clinical features suggesting polycystic ovarian disease (PCOD). However, despite androgen levels similar to those of patients with typical PCOD, high serum LH to FSH ratios were not consistently found. Seven other women (39%) presented with isolated hirsutism, suggesting idiopathic hirsutism. The remaining 4 women (22%) had no manifestations of androgen excess and were considered to have the cryptic form of LOHD. Serum 17-hydroxyprogesterone (17-OHP) and androgen levels were similar in the 3 phenotypes, suggesting that the clinical expression of LOHD in women is modulated by individual factors, such as androgen sensitivity. The 2 men were detected by family study and were clinically normal. Since clinical diagnosis of LOHD is impossible, we concentrated on hormonal data with the aim of providing guidelines for the biological diagnosis of LOHD. Assay of basal serum 17-OHD at 0800 h in both sexes and in the early follicular phase in women was sufficient to establish the diagnosis of LOHD in most patients. If doubtful results are obtained, i.e. serum 17-OHP levels between 2 and 5 ng/ml, an ACTH test must be performed. Post-ACTH serum 17-OHP levels exceeding 10 ng/ml confirm the diagnosis of LOHD. Such results should avoid confusion with heterozygotes for 21-hydroxylase deficiency, whose frequency is high within the general population and may be even higher in patients with idiopathic hirsutism or PCOD.

17-alpha-Hydroxyprogesterone↗