Publications (34)77.44 Total impact

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    ABSTRACT: We hypothesized that anorectics with or without bulimic features would differ on impulsivity and indices of central serotoninergic function (high impulsivity being correlated with reduced serotoninergic function). For all patients impulsivity rating scales and questionnaires detailing severity of eating disorder were assessed, and whole blood serotonin concentration (5-HT), free and total tryptophan (TT) concentrations, and large neutral amino acids (LNAA) were assayed. Nineteen patients with anorexia nervosa were included, 10 presented associated bulimic features and nine did not. Twelve healthy matched controls were also included. Our hypothesis was not verified. However, tryptophan concentration and the ratio of tryptophan concentration to LNAA allow us to separate controls from anorectics, whereas 5-HT concentration does not. Two significant and positive correlations were found: between impulsivity and anxiety in the total anorectic population, and between anxiety and serotonin in the impulsive group. All measured peripheral biologic indices except 5-HT concentration may be of interest in this pathology. Impulsivity and anxiety seem to be two personality components involved in anorexia nervosa. This study lead us to the necessity of redefining impulsivity in anorexia nervosa.
    No preview · Article · Mar 1998 · Biological Psychiatry
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    ABSTRACT: We report a hypertensive child with renal artery stenosis who exhibited increased urinary excretion of norepinephrine (NE) and normetanephrine (NMN), while vanillylmandelic acid (VMA) excretion was within the normal range. The NMN values prompted us to investigate the patient for pheochromocytoma; for this purpose, NE was determined by plasma catecholamine assays in venous samples obtained by catheterization. The moderately increased NE levels could not be localized to any particular sampling site. Arteriography demonstrated right renal artery abnormalities. Following right nephrectomy with preservation of the right adrenal gland, arterial blood pressure returned to normal. The cause of increased NMN excretion without a concomitant rise in VMA during hypertension is discussed.
    No preview · Article · Oct 1996 · Pediatric Nephrology
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    ABSTRACT: Neuroblastomas are malignant tumors derived embryonically from the neural crest. Biological diagnosis relies on assay of urinary excretion of homovanillic acid (HVA), vanillylmandelic acid (VMA), and dopamine (DA). Spontaneous regression of these neoplasms has been reported by numerous investigators. The authors report the case of a child with neuroblastoma that illustrates the relationship between catecholamine metabolites and tumor maturation. At 1 month of age, this infant presented an adrenal neuroblastoma with multiple metastases (stage IV); the initial histological diagnosis based on examination of cutaneous metastases was neuroblastoma. At the age of 6 months, after chemotherapy, the primary tumor was resected; hepatic metastases were discovered at laparotomy. The histological diagnosis for all lesions was highly differentiated, mature ganglioneuroma-like tissue. The main biochemical abnormality at the time of diagnosis was an elevation in normetanephrine (NMN). HVA was only slightly increased but rose progressively during chemotherapy; it dropped back to normal levels after the sixth course. This case illustrates the potential benefits of separate assays of urinary methylated catecholamine metabolites for biochemical diagnosis and therapeutic management of neuroblastoma in addition to assays of HVA, VMA, and DA. Case findings suggest existence of a transformation process with maturation of the tumor involving enzymatic regulation and expression of MAO.
    No preview · Article · Jan 1996 · Medical and Pediatric Oncology
  • M Candito · J Durant · V Gurle · P Chambon · P Dellamonica

    No preview · Article · Oct 1995 · AIDS
  • Mirande Candito · Ante M. Krstulovic · Pierre Chambon
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    ABSTRACT: 3,4-Dihydroxyphenylacetic acid (DOPAC) can be easily assayed by high-performance liquid chromatography (HPLC) with electrochemical detection at the same time as norepinephrine (NE), epinephrine (E), and dopamine (DA). The latter catecholamines are stable in perchloric acid extracts for over 6 h at 4 degrees C in the dark whereas DOPAC levels drop rapidly by more than 50% in 6 h at 4 degrees C in the dark. This study investigated the effects of reducing agents [ascorbic acid, dithiothreitol (DTT), reduced glutathione with or without a metal chelating agent (diethylenetriaminepentaacetic acid or ethylenediaminetetraacetic acid)] on DOPAC. Extracted with alumina using 0.65 mmol/1 DTT prior to HPLC and electrochemical detection, DOPAC remained stable in the perchloric acid extract for 2 h at 4 degrees C in the dark.
    No preview · Article · Aug 1995 · Journal of chromatography. B, Biomedical applications
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    ABSTRACT: alpha-Aminoadipic acid (alpha AA) is an intermediate in lysine metabolism. We report a new case with alpha AA excess in urine and plasma, without alpha-ketoadipic acid, in a full-term male child born to unrelated parents; he presented at 24h of life with seizures that failed to respond to phenobarbital, clonazepam, and Vigabatrin and death occurred on the 38th day of life. Brain imaging suggested antenatal haemorrhage. Small quantities of alpha AA were also detected in the blood and urine of both parents and a healthy brother, all three of whom exhibited the same defect in platelet aggregation as the deceased child. Both parents had decreased levels of plasma neopterin, a finding that might be related to the immunodeficiency described in other cases.
    No preview · Article · Feb 1995 · Journal of Inherited Metabolic Disease
  • M Candito · P Parvy · J Bardet · D Rabier · P Chambon · R Mariani · P Kamoun

    No preview · Article · Feb 1995 · Annales de biologie clinique
  • M Candito · T Nagatsu · P Chambon · M Chatel
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    ABSTRACT: Cerebrospinal fluid (CSF) samples from patients with a variety of neurological disorders were assayed to determine the concentrations of tetrahydrobiopterin (BH4), the active cofactor of hydroxylases. Dihydroneopterin (NH2) and neopterin (N), which are linked with BH4 synthesis and are inflammatory biochemical markers, were also measured simultaneously in a number of patients. 5-Hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA), the main products of serotonin and dopamine breakdown, were analyzed in parallel whenever possible. As BH4 and NH2 are difficult to analyze owing to their instability, CSF samples were collected under special conditions to preserve the reduced BH4 and NH2. Liquid chromatographic assays and detection of the various substances measured also required particular precautions. BH4 concentrations were elevated in patients with neurological disorders such as syphilis and lupus-like disease and especially in an AIDS patient with neurological complications with an increased N/BH4 ratio.
    No preview · Article · Aug 1994 · Journal of chromatography. B, Biomedical applications

  • No preview · Article · Feb 1994 · Journal of Inherited Metabolic Disease
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    ABSTRACT: High Homocyst(e)ine levels (H) have been recently recognized as a risk factor for atherosclerosis. Patients with Diabetes Mellitus (DM) are prone to atherosclerosis. Therefore, this study was designed to search for the effect of DM on H and their relationship. Forty-one Type 1 diabetic subjects (DS, age 34.8 +/- 12 yr, DM duration: 10.7 +/- 11.1 yr) were compared to 40 age-matched control subject (CS, age 34.2 +/- 9.1 yr). H (measured by ion-exchange chromatography, units: mumol/l) and several parameters (creatininemia; triglycerides; total, HDL, LDL cholesterol; Lp(a); HbA1c; vitamins B9 and B12) were determined after an overnight fast. H were significantly (p = 0.0001) lower in DS (6.8 +/- 2.2) than in CS (9.5 +/- 2.9). This difference was still apparent in male and female subgroups compared to matched CS (p = 0.003 for each). No correlation was found between H and: lipids, vitamins, renal or retinal status. But H seemed to increase with age, especially in women (p = 0.03; r = 0.32). While there is, at this time, no explanation for the lower H observed in DS, it appears that H cannot directly account for accelerated atherosclerosis in DM. Nevertheless, it remains to be established if high, or even normal, H could identify a subgroup of DS at higher risk of precocious and severe atherosclerosis.
    No preview · Article · Jan 1994 · Diabète & métabolisme
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    ABSTRACT: Cerebral serotonin is synthetized from its blood precursor: tryptophan (TRP), an essential amino acid (6). TRP has been extensively studied since serotonine has been reported to be involved in the pathogenesis of depression (9). In one hand, brain serotonin content depends on regulation by plasma large neutral amino acids (LNAA): leucine, isoleucine, valine, tyrosine and phenylalanine that compete with TRP to cross over the blood brain barrier (7, 13). In the other hand TRP is largely linked with albumin. So, we have studied plasma total TRP, free TRP and the ratio TRP on LNAA as potential cerebral serotonin index. The aim of this study is to observe the blood variations of the biological parameters in fasting and postprandial conditions in 8 depressed women, aged from 57 to 78 years, on a short protein controlled diet: 4 women had TRP poor then rich diet and the others 4 rich then poor. Alimentary proteins modulated diets and each patient was his own control: the results under modulated diet were compared with those under normal diet at the same time. More over, 2 psychotic patients aged 58 and 70 years have been studied at the same time, in each group. Biological datas were compared with clinical evolution.
    No preview · Article · Jan 1994 · L Encéphale
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    ABSTRACT: While blood norepinephrine and epinephrine levels are well established in adults, literature data concerning concentrations in young children are conflicting. This situation prompted us to assay plasma catecholamines in 86 healthy subjects aged two days to fifteen years using a sensitive high-performance liquid chromatography technique with electrochemical detection. Norepinephrine and epinephrine concentrations remained elevated up until 24 months of age, then dropped progressively to adult levels between 24 and 36 months, with fluctuations. These fluctuations, which reflect the sensitivity of children to environmental factors, prevented demonstration of any catecholaminergic secretory abnormality by blood assays in subjects under two years of age. Urinary assays, for which established values exist, are the only applicable procedure in such patients.
    No preview · Article · Sep 1993 · Journal of Chromatography A
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    ABSTRACT: A simple high-performance liquid chromatographic assay for serum neopterin with highly sensitive fluorimetric detection (limit 1 nM) is proposed. Comparison with results obtained by radioimmunoassay revealed a good correlation between the two techniques. The potential use of this method for the follow-up of liver transplant patients is discussed.
    No preview · Article · May 1993 · Journal of Chromatography A

  • No preview · Article · Feb 1993 · Journal of Inherited Metabolic Disease
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    ABSTRACT: 5-methoxypsoralen (5-MOP), a serotonin analogue, stimulates the secretion of melatonin, which plays an important role in circadian rhythm regulation. Melatonin production is essentially controlled by noradrenaline (NA). To investigate the effect of 5-MOP on the 24 hr NA rhythm, hourly plasma NA concentrations measured over 24 hr in 7 healthy young subjects who took 40 mg 5-MOP orally at 21:00 hr the evening before were compared with values obtained in drug-free subjects. All subjects were sleep-deprived and under conditions in which sympathetic nervous system activation was repeated every hour over 24 hr. In both series of patients, a significant difference was observed between mean morning values and mean night values, reflecting persistence of a circadian rhythm. In subjects given 5-MOP, a significant difference was also observed between mean afternoon values and mean night values. However, MANOVA analysis failed to find any difference between the two series of subjects. Acute administration of 5-MOP thus had no significant effect on the NA circadian rhythm under our study conditions.
    No preview · Article · Feb 1993 · Life Sciences
  • M Candito · F Askenazy · M Myquel · P Chambon · G Darcourt
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    ABSTRACT: Tryptophan (TRP) and tyrosine (TYR), respectively the circulating precursors of the central serotonergic (5-HT) and catecholamine systems, were measured in eight adolescents with impulsive behavior regardless of the exact type of disorder. The 6 week study period included weekly blood sampling and clinical evaluation. The ratios of TRP and TYR to large neutral amino acids (LNAA), which indicate the availability for the synthesis of neurotransmitters, were calculated. Comparison of results with eight hospitalized controls of the same age (12.5 to 18 years) revealed lower total TRP levels in four adolescent patients, a lower TRP/LNAA ratio in three adolescents, and a lower free TRP concentration in six adolescents with discretely enhanced albuminemia. A slight increase in TYR and the TYR/LNAA ratio was noted in nearly all of the adolescent patients. Despite the heterogeneity of individual biological results, the impulsive behavior subjects in this study seemed to present abnormalities in neurotransmitter precursors.
    No preview · Article · Feb 1993 · International Clinical Psychopharmacology
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    ABSTRACT: Under normal sleep-wake conditions, noradrenaline (NA) secretions in supine subjects exhibit a weak circadian variation with a peak that occurs around noon; the sleep span is characterized by reduced NA secretion. Some investigators have reported that the circadian NA rhythm is completely obliterated during sleep deprivation. In our laboratory, plasma NA was assayed every hour for 24 h in nine healthy men 20-23 years of age. All men were deprived of sleep and were required to eat and walk around every hour to prevent sleep. However, subjects remained supine for 20 min before blood samples were collected to eliminate the effect of activity. Persistence of a slight decrease in the night concentration in several subjects, despite sleep deprivation, suggests that NA secretion may be influenced by a biological clock whose activity becomes visible when the influence of posture is removed.
    No preview · Article · Jan 1993 · Chronobiology International
  • M Candito · S Bekri · P Monpoux · F Parisot · R Mariani · P Chambon
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    ABSTRACT: A five-year-old child presented with a large undifferentiated sarcoma in the right lung. Urinary catecholamines were assayed as tumor markers. A short-lived but significant rise in urinary norepinephrine and dopamine followed by rises in urinary levels of corresponding breakdown products were evidenced.
    No preview · Article · Jan 1993 · Pathologie Biologie
  • Mirande Candito · Bernard Krebs · Pierre Chambon

    No preview · Article · Jul 1992 · Clinica Chimica Acta
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    ABSTRACT: The authors investigated hourly total plasma tryptophan concentrations over a 24 hour period in 3 patients with bipolar depression during 2 types of treatment: a phase advance process and conventional antidepressant therapy. Both treatment modalities increased the 24 hour mean tryptophan levels and the amplitude of circadian tryptophan concentrations. By contrast, in a previous study, moderately decreased tryptophan levels and a blunted amplitude in the circadian rhythm were observed in these same patients in a depressive phase.
    No preview · Article · Feb 1992 · Life Sciences