6 research outputs found
New 8-nitroquinolinone derivative displaying submicromolar in vitro activities against both Trypanosoma brucei and cruzi
International audienceAn antikinetoplastid pharmacomodulation study was conducted at position 6 of the 8-nitroquinolin-2(1H)-one pharmacophore. Fifteen new derivatives were synthesized and evaluated in vitro against L. infantum, T. brucei brucei, and T. cruzi, in parallel with a cytotoxicity assay on the human HepG2 cell line. A potent and selective 6-bromo-substituted antitrypanosomal derivative 12 was revealed, presenting EC50 values of 12 and 500 nM on T. b. brucei trypomastigotes and T. cruzi amastigotes respectively, in comparison with four reference drugs (30 nM †EC50 †13 ÎŒM). Moreover, compound 12 was not genotoxic in the comet assay and showed high in vitro microsomal stability (half life >40 min) as well as favorable pharmacokinetic behavior in the mouse after oral administration. Finally, molecule 12 (E° = â0.37 V/NHE) was shown to be bioactivated by type 1 nitroreductases, in both Leishmania and Trypanosoma, and appears to be a good candidate to search for novel antitrypanosomal lead compounds
First determination of the incidence of the unique TOR1A gene mutation, c.907delGAG, in a Mediterranean population.
The c.907delGAG mutation in the TOR1A gene (also named DYT1) is the most common cause of early-onset primary dystonia. The mutation frequency and prevalence have so far been only estimated from rare clinical epidemiological reports in some populations. The purpose of this study was to investigate the incidence at birth of the c.907delGAG mutation in a French-representative mixed population of newborn from South-Eastern France. We applied an automated high-throughput genotyping method to dried blood spot samples from 12,000 newborns registered in H?ult between 2004 and 2005. Only one allele was found to carry the mutation, which allows to determine its incidence at birth as 1/12,000 per year in this area. (c) 2007 Movement Disorder Society
PrĂ©vention du carcinome rĂ©nal : lâapproche nutrigĂ©nĂ©tique
La frĂ©quence du cancer du rein (RCC), 3 % des cancers humains, augmente dans les pays industrialisĂ©s, laissant supposer lâintervention de facteurs toxiques (xĂ©nobiotiques et/ou alimentation, trichlorĂ©thylĂšne, tabagisme et obĂ©sitĂ©). Le RCC survient le plus souvent sous forme sporadique mais est Ă©galement retrouvĂ© dans un contexte familial : la maladie de von Hippel-Lindau (VHL). Lâexistence, dâune part, dâune grande hĂ©tĂ©rogĂ©nĂ©itĂ© intra- et inter-familiale dans le contexte du VHL et, dâautre part, la susceptibilitĂ© variable Ă des carcinogĂšnes chimiques dans les formes sporadiques, laisse supposer, en outre, la participation de gĂšnes modificateurs conditionnels. Afin dâidentifier des sous-groupes dâindividus particuliĂšrement exposĂ©s ou, au contraire, protĂ©gĂ©s du fait de certains gĂ©notypes, nous avons collectĂ© une sĂ©rie de 460 tumeurs et de patients appartenant Ă 79 familles VHL et dĂ©veloppĂ© un outil informatique, lâ« universal mutation database » (UMD) pour les mutations du gĂšne VHL, permettant de rechercher des corrĂ©lations. Les mutations du gĂšne VHL Ă lâorigine Ă la fois des RCC sporadiques et de la maladie de VHL sont de nature diffĂ©rente : 1) dans les tumeurs sporadiques, 83 % des mutations du gĂšne VHL sont des mutations aboutissant Ă un dĂ©calage du cadre de lecture (dĂ©lĂ©tion, insertion, non-sens = « frameshift »). Les 17 % restant comprennent des transversions (3/4) et des transitions (1/4). Cette proportion Ă©levĂ©e de transversions suggĂšre fortement lâimplication de substances carcinogĂšnes (fumĂ©e de tabac) dont lâimpact est largement conditionnĂ© par la variabilitĂ© gĂ©nĂ©tique de lâactivitĂ© des enzymes de biotransformation ; 2) pour les formes familiales, les mutations de type faux sens prĂ©dominent dans 65 % des cas. Cette diffĂ©rence permet de dĂ©finir un facteur pronostique de dĂ©velopper un RCC pour les patients VHL en fonction de la nature de la mutation germinale dont ils sont porteurs. Afin de repĂ©rer les gĂ©notypes confĂ©rant un risque Ă©levĂ© en prĂ©sence de substances potentiellement carcinogĂšnes, nous avons Ă©tabli le gĂ©notype des patients pour 8 gĂšnes (une cinquantaine de gĂ©notypes) impliquĂ©s dans le mĂ©tabolisme des xĂ©nobiotiques. Cette Ă©tude fait apparaĂźtre une relation significative entre le dĂ©veloppement dâun RCC et des combinaisons dâallĂšles comprenant : CYPIA1 ("variant"), NAT2 et NAT1 (acĂ©tyleurs lents) et GSTM1 (allĂšle nul). DâĂ©ventuelles associations entre les gĂ©notypes "Ă risque" et le profil des mutations somatiques observĂ©es chez les patients, mais aussi Ă diffĂ©rents stades tumoraux, pourraient aider Ă 1) prĂ©ciser la nature de certains profils de mutagenĂšse en relation avec lâactivitĂ© ou la dĂ©ficience de telle ou telle enzyme du mĂ©tabolisme des xĂ©nobiotiques et sous lâeffet de tel ou tel carcinogĂšne ; 2) montrer que, dans le contexte du VHL, certaines combinaisons dâallĂšles de ces diffĂ©rents gĂšnes confĂšrent un risque particulier de dĂ©velopper certains types de tumeur. Ainsi, suivre "Ă la trace" des substances potentiellement carcinogĂšnes, Ă la fois par lâempreinte laissĂ©e au niveau de lâADN, ainsi quâĂ travers les allĂšles conditionnellement dĂ©lĂ©tĂšres de gĂšnes participant Ă leur dĂ©toxication, devrait permettre une meilleur prĂ©vention grĂące Ă une alimentation personnalisĂ©e pour les individus prĂ©sentant ces gĂ©notypes
Is the early-onset torsion dystonia (EOTD) linked to TOR1A gene as frequent as expected in France?
International audienceEarly onset torsion dystonia are rare movement disorders. Molecular defect is known for only a subgroup, consisting of a unique and recurrent mutation in the TOR1A gene. We undertook a nationwide census of French TOR1A-mutation carriers and the assessment of clinical associated signs. Overall, 53 index cases and 104 relatives were studied and haplotypes linked to the mutation constructed. The previously reported Ashkenazi-Jewish haplotype was found in 11 families with the remainder carrying distinct haplotypes suggesting independent mutation events. This study demonstrates the scarcity of this disease in France with estimated disease frequency of 0.13:100,000 and mutation frequency of 0.17:100,000