<p>Studies were performed on methodological issues on vitamin A intake, status and improvement in three Asian countries, to improve the dietary approach recommended by FAO/WHO to alleviate vitamin A deficiency in low-income countries.</p><p>The reliability of the practical 24-hour dietary recall method to assess individual intake of vitamin A during pregnancy was investigated in Central Java, Indonesia. The usual mean intake of vitamin A can be reliably measured, but data on attenuation of simple regression coefficients suggest that it is difficult to establish associations between vitamin A intake and some health outcome. The majority of women was below the recommended daily intake of vitamin A in all three trimesters and strategies to improve vitamin A intake in all women are thus needed.</p><p>The applicability of the simplified "Helen Keller International Food Frequency Method" to assess community risk of vitamin A deficiency in South Asia, even though it excludes breastmilk and animal milk, was tested in rural Bangladesh and rural India. Breast milk was found to be an important source of vitamin A even in the second and third years of life in rural areas of Bangladesh. Similarly, animal milk is likely to be an important source of vitamin A among preschoolers in certain areas of India. The method should be revalidated to make it a useful tool even in settings where breastmilk and animal milk are common in the diets of preschool children.</p><p>Whether it is possible to improve vitamin A status with dark green leafy vegetables in children free of <i>Ascaris lumbricoides</i> was investigated in northern Bangladesh. A substantial increase in serum β-carotene was seen after supplementary feeding of these vegetables for 6 weeks. The impact on serum retinol concentrations was less substantial.</p>

Studies were performed on methodological issues on vitamin A intake, status and improvement in three Asian countries, to improve the dietary approach recommended by FAO/WHO to alleviate vitamin A deficiency in low-income countries. The reliability of the practical 24-hour dietary recall method to assess individual intake of vitamin A during pregnancy was investigated in Central Java, Indonesia. The usual mean intake of vitamin A can be reliably measured, but data on attenuation of simple regression coefficients suggest that it is difficult to establish associations between vitamin A intake and some health outcome. The majority of women was below the recommended daily intake of vitamin A in all three trimesters and strategies to improve vitamin A intake in all women are thus needed. The applicability of the simplified "Helen Keller International Food Frequency Method" to assess community risk of vitamin A deficiency in South Asia, even though it excludes breastmilk and animal milk, was tested in rural Bangladesh and rural India. Breast milk was found to be an important source of vitamin A even in the second and third years of life in rural areas of Bangladesh. Similarly, animal milk is likely to be an important source of vitamin A among preschoolers in certain areas of India. The method should be revalidated to make it a useful tool even in settings where breastmilk and animal milk are common in the diets of preschool children. Whether it is possible to improve vitamin A status with dark green leafy vegetables in children free of Ascaris lumbricoides was investigated in northern Bangladesh. A substantial increase in serum β-carotene was seen after supplementary feeding of these vegetables for 6 weeks. The impact on serum retinol concentrations was less substantial.

Introduction : La Vitamine A (rétinol, ROL) et son métabolite l’acide rétinoïque (AR) sont essentielles pour l’embryogénèse. L’excès comme l’insuffisance d’AR sont nocives. L’AR est régularisé dans l’embryon par des gènes spécifiques (ALDH, CRABP, CYP). Hypothèse : Les grandes variations d’AR dans le plasma des adultes normaux, nous ont orienté à mesurer les rétinoïdes (ROL et RA) dans le sang de cordon ombilical, pour évaluer des corrélations avec des polymorphismes des gènes impliquées dans le métabolisme de l’AR et le développement rénal-(RALDH2, CRABP2, CYP26A1; B1). Vérifier pour des corrélations entre ces rétinoïdes et/ou avec la taille de reins à la naissance. Méthodes : Extraction du ROL et RA du sang de cordon ombilical de 145 enfants et analyse par HPLC. Le volume des reins a été mesuré par ultrasonographie et l’ADN génomique leucocytaire extrait (FlexiGene DNA-Kit). 10 échantillons d’ADN ont été exclus (qualité). Les htSNP : ALDH1A2, CRABP2, CYP26A1;B1 du génome humain (HapMap) ont été séquencés et génotypés (Sequenom iPlex PCR).Des testes bio-statistiques des fréquences génotypiques et alléliques ont été effectués (Single-Locus, χ2, Kruskal-Wallis, Allelic-Exact).Des corrélations (ROL, RA, SNPs, V-reins) ont été analysés (Kendall-tau /Oakes). Résultats : La Δ RA (0.07-550.27 nmol/l) non corrélé avec la Δ ROL (51.39-3892.70 nmol/l). Il n’y a pas d’association ROL ou RA avec les volumes des reins ou avec les SNPs/ CYP21A1;B1. Corrélations trouvées : 1. (p=0.035), polymorphisme génétique ALDH1A2-SNP (rs12591551:A/C) hétérozygote/CA, (25enfants, 19%) avec moyennes d’AR (62.21nmol/l). 2. (p=0.013), polymorphisme CRABP2-SNP (rs12724719:A/G) homozygote/AA (4 enfants, 3%) avec hautes valeurs moyennes d’AR (141,3 nmol/l). Discussion-Conclusion : Les grandes ΔRA suggèrent une variabilité génique individuelle du métabolisme de ROL. Les génotypes (CA)-ALDH1A2/ SNP (rs12591551:A/C) et (AA) -CRABP2/SNP (rs12724719:A/G) sont associés à des valeurs moyennes hautes d’AR, pouvant protéger l’embryogénèse lors d’une hypovitaminose A maternelle. / Introduction: Vitamin A (retinol, ROL) modulate the embryogenesis thorough RA, its metabolite. Excess or deficiency being pathologic, the RA is tight regulated in the embryo thorough specific genes (ALDH, CRABP, CYP, etc.) important for Vitamin A metabolism. Hypothesis: High RA variations in healthy adults plasma, oriented to ROL, RA evaluation in human cord blood, in regard of possible correlations with polymorphisms of genes involved in RA metabolism and kidney development (RALDH2, CRABP2, CYP26A1,B1). Correlations between ROL and RA and/or with birth kidney size might also occur. Methods: Cord blood ROL and RA were extracted and HPLC analysed, from 145 Montreal healthy newborns. Kidney volumes already measured by ultrasonography. Genomic leucocytary DNA extraction was performed with FlexiGene DNA-Kit. 10 samples excluded (DNA quality). htSNP choices: ALDH1A2, CRABP2, CYP26A1;B1 were made on HapMap human genome. Sequencing, genotyping (Sequenom iPlex PCR) was made for these genes eventual SNPs. Biostatistics tests for genotype and allelic frequencies (Single-Locus, χ2, Kruskal-Wallis, Allelic-Exact) and Kendall-tau /Oakes analysis for eventual ROL, RA, SNPs, V-reins correlations, were performed. Results: No correlation found between Δ RA (0.07-550.27 nmol/L) and Δ ROL (51.39-3892.70 nmol/L). No association ROL or RA with kidney volumes nor with SNPs/ CYP21A1;B1. Found correlations: 1. (p=0.035), polymorphism ALDH1A2-SNP (rs12591551:A/C) heterozygous/CA, (25babies, 19%) with RA (mean ~62.21nmol/L). 2. (p=0.013), polymorphism CRABP2-SNP (rs12724719: A/G) homozygous/AA (4babies, 3%) with RA (mean~141, 3 nmol/L). Discussion/Conclusion: Big Δ RA not correlated with Δ ROL suggests individual genetic variance on RA metabolism. Genotypes (CA)-ALDH1A2/SNP (rs12591551:A/C) and (AA)-CRABP2/SNP (rs12724719: A/G) are associated with high cord blood RA mean and may be embryogenesis protective in a maternal hypovitaminosis-A, environment.

En un intento de optimizar el sistema de fecundación in vitro en la especie porcina se estudió la influencia de distintas condiciones de maduración y de cocultivo de los gametos. Se evaluó la reducción del tiempo de coincubación de los gametos a 10 min observándose un claro efecto del ratio espermatozoides:ovocito. El estudio de las necesidades de los espermatozoides en términos de aditivos del medio de fecundación y tiempo de coincubación reveló variaciones entre verracos. La utilización de un tiempo de coincubación tan corto como 2 min fue suficiente para obtener unas tasas de penetración y monospermia similares a las alcanzadas por los sistemas de FIV tradicionales. El sistema de FIV en pajuela con 10 min de coincubación aumentó la penetración monoespérmica y mejoró la calidad de los blastocistos. La adición de 5 nM de 9- cis ácido retinoico al medio de maduración aumentó significativamente la formación de blastocistos. / The present study was conducted in an attempt to optimize porcine in vitro fertilization system. For this purpose, the influence of maturation and gamete coculture conditions were studied. The coincubation time may be reduced to 10 min to increase the efficiency of fertilization depending on the sperm:oocytes ratio. The needs of boar spermatozoa for IVF, in terms of additives to IVF medium and coincubation times vary among boars. The use of coincubation time as brief as 2 min is long enough to obtain good fertilization rates similar to those achieved from current long term exposure times in IVF. A straw IVF system in combination with a 10 min coincubation increased monospermic penetration and the quality of blastocysts compared with the microdrop-IVF system. The addition of 5 nM of 9- cis retinoic acid in the IVM medium increased blastocyst formation rate, suggesting that RA may play an important role during IVM.

RÉSUMÉ: Introduction : La Vitamine A (rétinol, ROL) et son métabolite l’acide rétinoïque (AR) sont essentielles pour l’embryogénèse. L’excès comme l’insuffisance d’AR sont nocives. L’AR est régularisé dans l’embryon par des gènes spécifiques (ALDH, CRABP, CYP). Hypothèse : Les grandes variations d’AR dans le plasma des adultes normaux, nous ont orienté à mesurer les rétinoïdes (ROL et RA) dans le sang de cordon ombilical, pour évaluer des corrélations avec des polymorphismes des gènes impliquées dans le métabolisme de l’AR et le développement rénal-(RALDH2, CRABP2, CYP26A1; B1). Vérifier pour des corrélations entre ces rétinoïdes et/ou avec la taille de reins à la naissance. Méthodes : Extraction du ROL et RA du sang de cordon ombilical de 145 enfants et analyse par HPLC. Le volume des reins a été mesuré par ultrasonographie et l’ADN génomique leucocytaire extrait (FlexiGene DNA-Kit). 10 échantillons d’ADN ont été exclus (qualité). Les htSNP : ALDH1A2, CRABP2, CYP26A1;B1 du génome humain (HapMap) ont été séquencés et génotypés (Sequenom iPlex PCR).Des testes bio-statistiques des fréquences génotypiques et alléliques ont été effectués (Single-Locus, χ2, Kruskal-Wallis, Allelic-Exact).Des corrélations (ROL, RA, SNPs, V-reins) ont été analysés (Kendall-tau /Oakes). Résultats : La Δ RA (0.07-550.27 nmol/l) non corrélé avec la Δ ROL (51.39-3892.70 nmol/l). Il n’y a pas d’association ROL ou RA avec les volumes des reins ou avec les SNPs/ CYP21A1;B1. Corrélations trouvées : 1. (p=0.035), polymorphisme génétique ALDH1A2-SNP (rs12591551:A/C) hétérozygote/CA, (25enfants, 19%) avec moyennes d’AR (62.21nmol/l). 2. (p=0.013), polymorphisme CRABP2-SNP (rs12724719:A/G) homozygote/AA (4 enfants, 3%) avec hautes valeurs moyennes d’AR (141,3 nmol/l). Discussion-Conclusion : Les grandes ΔRA suggèrent une variabilité génique individuelle du métabolisme de ROL. Les génotypes (CA)-ALDH1A2/ SNP (rs12591551:A/C) et (AA) -CRABP2/SNP (rs12724719:A/G) sont associés à des valeurs moyennes hautes d’AR, pouvant protéger l’embryogénèse lors d’une hypovitaminose A maternelle. Mots clé: sang de cordon ombilical, ROL-rétinol, AR-acide rétinoïque, HPLC, SNP- polymorphisme, ALDH1A2, CRABP2, CYP26A1,développement rénal,embryogénèse. / ABSTRACT Introduction: Vitamin A (retinol, ROL) modulate the embryogenesis thorough RA, its metabolite. Excess or deficiency being pathologic, the RA is tight regulated in the embryo thorough specific genes (ALDH, CRABP, CYP, etc.) important for Vitamin A metabolism. Hypothesis: High RA variations in healthy adults plasma, oriented to ROL, RA evaluation in human cord blood, in regard of possible correlations with polymorphisms of genes involved in RA metabolism and kidney development (RALDH2, CRABP2, CYP26A1,B1). Correlations between ROL and RA and/or with birth kidney size might also occur. Methods: Cord blood ROL and RA were extracted and HPLC analysed, from 145 Montreal healthy newborns. Kidney volumes already measured by ultrasonography. Genomic leucocytary DNA extraction was performed with FlexiGene DNA-Kit. 10 samples excluded (DNA quality). htSNP choices: ALDH1A2, CRABP2, CYP26A1;B1 were made on HapMap human genome. Sequencing, genotyping (Sequenom iPlex PCR) was made for these genes eventual SNPs. Biostatistics tests for genotype and allelic frequencies (Single-Locus, χ2, Kruskal-Wallis, Allelic-Exact) and Kendall-tau /Oakes analysis for eventual ROL, RA, SNPs, V-reins correlations, were performed. Results: No correlation found between Δ RA (0.07-550.27 nmol/L) and Δ ROL (51.39-3892.70 nmol/L). No association ROL or RA with kidney volumes nor with SNPs/ CYP21A1;B1. Found correlations: 1. (p=0.035), polymorphism ALDH1A2-SNP (rs12591551:A/C) heterozygous/CA, (25babies, 19%) with RA (mean ~62.21nmol/L). 2. (p=0.013), polymorphism CRABP2-SNP (rs12724719: A/G) homozygous/AA (4babies, 3%) with RA (mean~141, 3 nmol/L). Discussion/Conclusion: Big Δ RA not correlated with Δ ROL suggests individual genetic variance on RA metabolism. Genotypes (CA)-ALDH1A2/SNP (rs12591551:A/C) and (AA)-CRABP2/SNP (rs12724719: A/G) are associated with high cord blood RA mean and may be embryogenesis protective in a maternal hypovitaminosis-A, environment. Key words: umbilical cord blood, ROL-retinol, AR-retinoic acid, HPLC, SNP- polymorphism, ALDH1A2, CRABP2, CYP26A1,kidney development,embryogenesis. / Note d'excellence 10%: « Le Jury, à l'unanimité, juge ce mémoire excellent et le classe parmi les 10% des mémoires de la discipline » - selon le Rapport définitif du jury d'éxamen d'un mémoire de maîtrise.