Enantiomers of nifurtimox do not exhibit stereoselective anti-Trypanosoma cruzi activity, toxicity, or pharmacokinetic properties

With the aim of improving the available drugs for the treatment of Chagas disease, individual enantiomers of nifurtimox were characterized. The results indicate that the enantiomers are equivalent in their in vitro activity against a panel of Trypanosoma cruzi strains; in vivo efficacy in a murine model of Chagas disease; in vitro toxicity and absorption, distribution, metabolism, and excretion characteristics; and in vivo pharmacokinetic properties. There is unlikely to be any therapeutic benefit of an individual nifurtimox enantiomer over the racemic mixture

Interlaboratory control among INCO-DEV MYCOTOX PROJECT LABORATORIES

The Work Package 1 “ Development and standardization of effective analytical tools for mycotoxin (aflatoxins B1, B2  G1, G2  ochratoxin A, zearalenone, fumonisin B1, B2  and tricothecenes) determination in wheat and maize”  aim to implement the interlaboratory control between the partners laboratories from Brazil, Uruguay, Chile and Argentina as part of the objectives of INCO-DEV MYCOTOX PROJECT 2003-2005  “The Development of a Food Quality Management System for the Control of Mycotoxins in cereal Production and Processing Chains in Latin America South Cone Countries”.  The ojectives of the interlaboratory control were: evaluate the performance of the laboratories and the main difficulties encountered in performing the analytical procedure for mycotoxins  determination in maize and wheat; contribute to the harmonization of analytical procedures of the partners laboratories and contribute to the laboratory’s proficiency in mycotoxin analysis.  Maize reference materials for aflatoxins and zearealenone were prepared and used to the implementation of the interlaboratory control.  In summary, the preparation of these samples involved: milling (<20 mesh), homogeneization, analysis to verify the homogeneity of the bulk material and packing (labelled vacuum “sachets” or plastic bottles) and mycotoxin analysis.  The homogeneity of the material was investigated by the analysis of variance – ANOVA- according to International Harmonized Protocol for the Proficiency testing of (Chemical)Analytical Laboratories as established by ISO 43-1 – Annex at 95% of confidence level by calculating an F-statistic ans Ss/ÿ (ÿ =15%). All batches of test material were stored under – 18ºC and protected from light prior to and after packaging.  Aflatoxins in the test materials were determinated by immunoaffinity with liquid chromatography (LC) with pos-column derivatization and thin layer chromatography (TLC).  Zearalenone in the test materials were determined by solid phase column (Romer 224TM) with LC.  Four homogeneus maize materials were prepared: blank for zearalenone, blank for aflatoxins and two naturally contaminated for aflatoxins.  These samples were used to validated analytical methods and as reference samples for proficiency test.  The participating laboratories received refrigerated parcel containing: coded maize samples and blank for spiking purpose, test material receipt form, additional instructions, results reporting sheets and analytical work questionnaire in 3 rounds.  The results were evaluated by using z-score function being calculated considering the best value representing the true measure of mycotoxin in the sample (as per evaluation in the homogeneity tests).  Additional FAPAS test material for mycotoxins were purchased in order to assess the laboratory performance and to validated the reference materials.  In case of “questionable” or “unsatisfactory” results, the Laboratory were advised to treate them as non conforming work, make the necessary modifications and adjustments in the methods, taking into account the method performance criteria (CEN).  The laboratories were strongly recommended to write a report containing the analysis of the causes and correctives actions proposed, giving special attention to: correct use of calibrated pipettes; chromatographic condition including the calibration curve and injected volume of extract and standard

Neonatal administration of citalopram delays somatic maturation in rats

We investigated the somatic maturation of neonate rats treated during the suckling period with citalopram, a selective serotonin reuptake inhibitor. Groups with 6 male neonates were randomly assigned to different treatments 24 h after birth. Each litter was suckled by one of the dams until the 21st postnatal day. Body weight, head axis and tail length were measured daily from the 1st to the 21st postnatal day. Time of ear unfolding, auditory conduit opening, incisor eruption, and eye opening was determined. Pups received 5 mg (Cit5), 10 mg (Cit10) or 20 mg/kg (Cit20) citalopram sc, or saline (0.9% NaCl, w/v, sc). Compared to saline, body weight was lower (24.04%, P < 0.01) for Cit10 from the 10th to the 21st day and for Cit20 from the 6th to the 21st day (38.19%, P < 0.01). Tail length was reduced in the Cit20 group (15.48%, P < 0.001) from the 8th to the 21st day. A reduction in mediolateral head axis (10.53%, P < 0.05) was observed from the 11th to the 21st day in Cit10 and from the 6th to the 21st day in Cit20 (13.16%, P < 0.001). A reduction in anteroposterior head axis was also observed in the Cit20 group (5.28%, P < 0.05) from the 13th to the 21stday. Conversely, this axis showed accelerated growth from the 12th to the 21stday in the Cit5 group (13.05%, P < 0.05). Auditory conduit opening was delayed in the Cit5 and Cit20 groups and incisor eruption was delayed in all citalopram groups. These findings show that citalopram injected during suckling to rats induces body alterations and suggest that the activity of the serotoninergic system participates in growth mechanisms

Eficiência da seleção para incremento do teor de óleo do pinhão-manso

O objetivo deste trabalho foi estimar os parâmetros genéticos de características de qualidade de grãos de pinhão-manso (Jatropha curcas) e quantificar o progresso genético da seleção. O teor de óleo dos grãos e os pesos de grãos, amêndoas e casca de 120 plantas, selecionadas ao acaso em plantio comercial, foram avaliados aos 36 e 48 meses de cultivo. O progresso genético foi quantificado por meio da avaliação dos ganhos diretos e da utilização de índices de seleção. O efeito da interação genótipos x medição foi significativo para todas as características avaliadas; portanto, há genótipos com comportamento diferenciado nas duas colheitas. Os parâmetros genéticos indicaram predominância da variação genotípica na expressão das características avaliadas, e observou-se tendência de manutenção da superioridade dos genótipos ao longo do tempo. O índice de seleção genótipo-ideótipo resultou em maior ganho total e promoveu alteração mais equilibrada na média das características. A seleção direta para peso de amêndoa resulta em ganhos totais semelhantes aos obtidos com a utilização dos índices de seleção