Publications by authors named "Michel Lhermitte"

Aims: In response to acute ethanol consumption, tryptophan 2,3-dioxygenase (TDO) induces the kynurenine pathway (KP) through a glucocorticoid-mediated mechanism, which could lead to a dramatic accumulation of neurotoxic metabolites in association with serotonin depletion. As a result, interindividual variability in ethanol-induced behavioural disorders, such as black-outs and violent impulsive behaviours (BOVIBs) following binge drinking, could be partly explained by genetic polymorphisms affecting the KP. The aim of this study was to identify polymorphisms on the promoter of the TDO2 gene that could affect expression and/or activity of TDO through glucocorticoid induction.

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Tryptophan catabolism, which is mediated by the enzymes indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO), produces kynurenine. Kynurenine itself is converted by downstream enzymes into secondary catabolites. We evaluated the serum levels of primary and secondary tryptophan catabolites in a cohort of patients with myelodysplastic syndromes (MDS).

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The CYP4A subfamily is known to ω-hydroxylate the endogenous arachidonic acid into 20-hydroxyeicosatetranoic acid, which has renovascular and tubular functions. The aim of this work was to report a comprehensive investigation of the CYP4A11 and CYP4A22 genetic polymorphisms in a French population. Using PCR-SSCP and sequencing strategies, a total of 26 sequence variations were identified comprising 3 missense mutations for CYP4A11 (Ser404Phe, Phe434Ser and Arg505His) and 7 missense mutations for CYP4A22 (Arg126Trp, Gly130Ser, Asn152Tyr, Val185Phe, Cys231Arg, Leu428Pro and Leu509Phe).

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In clinical and forensic toxicology, general unknown screening is used to detect and identify exogenous compounds. In this study, we aimed to develop a fast (15 min) comprehensive screening method for 500 toxicologically relevant analytes based on ultra-performance liquid chromatography (UPLC) coupled with a quadrupole mass spectrometer (MS) system operated in full scan mode. Data were acquired using both positive and negative electrospray ionization by scanning across the range m/z 80-650.

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Rationale: In rats, prenatal restraint stress (PRS) induces persistent behavioral and neurobiological alterations leading to a greater consumption of psychostimulants during adulthood. However, little is known about alcohol vulnerability in this animal model.

Objectives: We examined in adolescent and adult male Sprague Dawley rats the long-lasting impact of PRS exposure on alcohol consumption.

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Susceptibility to lung diseases, such as lung cancer and chronic obstructive pulmonary disease, is largely influenced by the metabolic capacity of lung tissues. This capacity is partly determined by the expression profile of the cytochromes P450 (CYPs), a superfamily of enzymes that have relevant catalytic properties toward exogenous and endogenous compounds. Using quantitative real-time RT-PCR, we conducted a comprehensive analysis of the expression profile of the 57 human CYP genes in non-tumoral (bronchial mucosa and pulmonary parenchyma) and tumoral lung tissues of 18 patients with non-small cell lung cancer.

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Aims: We examined (1) the association of SLC6A4 genotypes and alcohol dependence (AD) in a sample of alcoholics; (2) the validity of lifetime occurrence of blacked-out violent impulsive behaviour (BOVIB) during binge drinking bouts as a criterion for subtyping AD patients and (3) a mechanistic hypothesis for BOVIB involving tryptophan-2,3-dioxygenase (TDO) activity.

Methods: Three common polymorphisms of the SLC6A4 gene (5-HTTLPR, A/G SNP of LPR region and VNTR in intron 2) were genotyped. An oral tryptophan (Trp) load (OTL) was administered to a sample of patients seeking help for AD.

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Background: Although it is generally believed that chronic ethanol consumption impairs learning and memory, results obtained in experimental animals are not univocal, and there are conditions in which ethanol paradoxically improves cognitive functions. In the present work, we investigated the effects of prenatal stress and of chronic ethanol exposure during adulthood on spatial memory in rats.

Methods: Rats were subjected to a prenatal stress delivered as 3 daily 45-minute sections of restraint stress to the mothers during the last 10 days of pregnancy (PRS rats).

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The enzyme indoleamine 2,3-dioxygenase (IDO) converts tryptophan to kynurenine, blocking T-cell activation and inducing immunosuppression. In patients with acute myeloid leukemia (AML), the serum kynurenine/tryptophan ratio (Kyn/Trp) was raised, suggesting a higher IDO activity than in healthy people. Patients with higher Kyn/Trp ratios showed lower survival.

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The determination and quantification of glyphosate in serum using (1)H NMR spectroscopy is reported. This method permitted serum samples to be analysed without derivatization or any other sample pre-treatment, using 3-trimethylsilyl 2,2',3,3'-tetradeuteropropionic acid (TSP-d(4)) as a qualitative and quantitative standard. Characterization of the herbicide N-(phosphonomethyl)glycine was performed by analysing chemical shifts and coupling constant patterns.

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Prenatal restraint stress (PRS) in rats is associated with hippocampal dysfunctions and several behavioural and endocrine disorders related to this brain area. Recently, we have reported that the PRS modifies the hypothalamic-pituitary-adrenal (HPA) response to an ethanol challenge in adolescent animals. Since hippocampus is particularly sensitive to the deleterious effects of ethanol during adolescence, we investigated in this study the combined effects of PRS and ethanol administration on the oxidative status in the hippocampus of 28-day-old male rats.

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A rapid and sensitive method using LC-MS/MS triple stage quadrupole for the determination of traces of amphetamine (AP), methamphetamine (MA), 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxymethamphetamine (MDMA, "ecstasy"), 3,4-methylenedioxyethamphetamine (MDEA), and N-methyl-1-(3,4-methylenedioxyphenyl)-2-butanamine (MBDB) in hair, blood and urine has been developed and validated. Chromatography was carried out on an Uptisphere ODB C(18) 5 microm, 2.1 mm x 150 mm column (Interchim, France) with a gradient of acetonitrile and formate 2 mM pH 3.

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A previous study conducted in 1995 showed that psychoactive drug use by workers was higher in safety/security workstations than in the rest of the labour force. In order to verify this finding, we conducted a new study in 2003-2004 in the Nord-Pas-de-Calais region, restricted to truck drivers. The aim of this study was to allow harmonizing the professional practice of the occupational physicians, proposing drug prevention and drug testing policies, validating the analytical methods and the guidelines in case of positive testing results.

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The CYP2F1 is a human cytochrome P450 that is selectively expressed in lung tissue and involved in the metabolism of various pneumotoxicants with potential carcinogenic effects. In the present study, we report the first systematic investigation of the genetic polymorphism of this enzyme. We analyzed the nucleotidic sequence of the CYP2F1 gene in DNA samples from 90 French Caucasians consisting in 44 patients with lung cancer and 46 control individuals, using single-strand conformation polymorphism analysis of PCR products (PCR-SSCP).

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We tested the ability of simvastatin, atorvastatin, fenofibrate and bezafibrate (two synthetic peroxisome proliferator-activated receptor-alpha (PPAR-alpha) agonists) to prevent dopaminergic cell death in the 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mouse model of Parkinson's disease. Tyrosine hydroxylase (TH) immunochemistry was performed 8 days after acute MPTP intoxication. When orally administered for the week prior to intoxication and a week thereafter, fenofibrate prevented the MPTP-induced dopaminergic cell loss in the substantia nigra pars compacta (SNpc) and attenuated the loss of tyrosine hydroxylase immunoreactivity in the striatum.

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An expeditious route to the two major metabolites of Zolpidem-and readily applicable to the synthesis of the drug-was established via a cyclization reaction between a 2-aminopyridine and a suitable alpha-bromoacetophenone. The structures of the target compounds were confirmed from a 2D (1)H-(15)N NMR correlation. Their mass spectra contribute to a reliable toxicological identification of the drug in the case of drug-facilitated crimes.

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Background: CYP26A1, together with CYP26B1 and CYP26C1, are key enzymes of all-trans retinoic acid (RA) inactivation and their specific and restricted expression in developing embryos participate in the fine tuning RA levels. As RA is a critical regulator of gene expression during embryonic development, the imbalance between the synthesis and degradation of RA during embryogenesis could contribute to malformations and developmental defects.

Methods: A PCR-single strand conformation polymorphism (PCR-SSCP) strategy was developed to screen for CYP26A1 sequence variations that could affect the enzyme expression and/or activity and applied to DNA samples from 80 unrelated Caucasians, comprising 40 French healthy volunteers and 40 Italian patients with spina bifida.

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The period of adolescence and environmental factors, such as stress, are important in determining ethanol vulnerability in both humans and rats. Ethanol is a powerful activator of the hypothalamic-pituitary-adrenal (HPA) axis but attenuated responses of the HPA axis to ethanol have been described in populations with a high risk of ethanol abuse. In rats, prenatal stress leads to prolonged stress-induced corticosterone secretion and increases the vulnerability to drugs of abuse, such as amphetamine and nicotine in adulthood and 3,4-methylenedioxymethamphetamine in adolescent rats.

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Interindividual variability in drug responses can complicate patient management. This variability is partly due to genetic factors that affect pharmacokinetic and pharmacodynamic behavior Pharmacogenetics is a discipline focusing on the molecular mechanisms underlying drug responses. Its overriding goal is to optimize drug treatments, in terms of both their efficacy and their safety.

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The purpose of this work is to characterize chemical compounds added to an ingested soda by (1)H nuclear magnetic resonance ((1)H NMR) spectroscopy and by gas chromatography-mass spectrometry in the electron impact mode. A second point was to highlight possible metabolic disturbances by considering urinary profile. Without any pretreatment, dimethylphtalate, 2-butanone, and 2,2,4-trimethylpentanediol diisobutyrate were found in the adulterated soda.

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The cytochrome P450 3A5 (CYP3A5) has been shown to be highly involved in the metabolism of many therapeutic agents. To date, several polymorphisms affecting the CYP3A5 gene have been identified but few studies have shown a complete description of the variability of the CYP3A5 in the French population. Therefore, the extent of CYP3A5 genetic polymorphism was investigated in a French population of 114 patients.

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Cytochrome P450 2D6 (CYP2D6) is an important human drug-metabolizing enzyme that exhibits a marked genetic polymorphism. Numerous CYP2D6 alleles have been characterized at a functional level, although the consequences for expression and/or catalytic activity of a substantial number of rare variants remain to be investigated. One such allele, CYP2D6*31, is characterized by mutations encoding three amino acid substitutions: Arg296Cys, Arg440His and Ser486Thr.

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The human cytochrome CYP4F12 has been shown to be metabolically active toward inflammatory mediators and exogenous compounds such as antihistaminic drugs. We recently identified a genetic polymorphism within the promoter region, associated with a decreased level of enzyme expression. In the present study, we report the further identification of single nucleotide polymorphisms in the coding sequence of the CYP4F12 gene.

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