Dietary vitamin A intake below the recommended daily intake during pregnancy and the risk of congenital diaphragmatic hernia in the offspring

BACKGROUND

Vitamin A has been related to the etiology of congenital diaphragmatic hernia (CDH). We performed a case‐control study to investigate whether maternal dietary vitamin A intake is related to CDH in the offspring.

METHODS

Thirty‐one pregnancies diagnosed with CDH and 46 control pregnancies were included during the study. After CDH diagnosis and inclusion of controls by risk set sampling, maternal vitamin A intake was investigated with a food frequency questionnaire. Serum retinol and retinol‐binding protein were determined. Univariable and multivariable logistic regression models were used to calculate risk estimates with adjustment for potential confounders.

RESULTS

We found no significant differences in the overall nutrient and vitamin A intake between case and control mothers. After stratification in body mass index (BMI) categories, case mothers with normal weight showed a lower energy adjusted vitamin A intake (685 vs. 843 μg retinol activity equivalents [RAEs] / day; p = 0.04) and a slightly lower serum retinol (1.58 vs. 1.67 μmol/L; p = 0.08) than control mothers. Vitamin A intake <800 μg retinol activity equivalents (recommended daily intake) in normal weight mothers was associated with a significantly increased CDH risk (odds ratio [OR], 7.2; 95% confidence interval [CI], 1.5–34.4; p = 0.01). Associations were not significantly different in underweight and overweight mothers.

CONCLUSIONS

In normal‐weight mothers, dietary vitamin A intake during pregnancy below the recommended daily intake is significantly associated with an increased risk of a child with CDH. This finding supports the retinoid hypothesis in human CDH, but warrants further investigation in larger study populations. Birth Defects Research (Part A), 2013. © 2013 Wiley Periodicals, Inc.     

Augmenting Endogenous Wnt Signaling Improves Skin Wound Healing

Wnt signaling is required for both the development and homeostasis of the skin, yet its contribution to skin wound repair remains controversial. By employing Axin2^LacZ/+ reporter mice we evaluated the spatial and temporal distribution patterns of Wnt responsive cells, and found that the pattern of Wnt responsiveness varies with the hair cycle, and correlates with wound healing potential. Using Axin2^LacZ/LacZ mice and an ear wound model, we demonstrate that amplified Wnt signaling leads to improved healing. Utilizing a biochemical approach that mimics the amplified Wnt response of Axin2^LacZ/LacZ mice, we show that topical application of liposomal Wnt3a to a non-healing wound enhances endogenous Wnt signaling, and results in better skin wound healing. Given the importance of Wnt signaling in the maintenance and repair of skin, liposomal Wnt3a may have widespread application in clinical practice.     

Quantitative-PCR assessment of Cryptosporidium parvum cell culture infection

A quantitative TaqMan PCR method was developed for assessing the Cryptosporidium parvum infection of in vitro cultivated human ileocecal adenocarcinoma (HCT-8) cell cultures. This method, termed cell culture quantitative sequence detection (CC-QSD), has numerous applications, several of which are presented. CC-QSD was used to investigate parasite infection in cell culture over time, the effects of oocyst treatment on infectivity and infectivity assessment of different C. parvum isolates. CC-QSD revealed that cell culture infection at 24 and 48 h postinoculation was approximately 20 and 60%, respectively, of the endpoint 72-h postinoculation infection. Evaluation of three different lots of C. parvum Iowa isolate oocysts revealed that the mean infection of 0.1 N HCl-treated oocysts was only 36% of the infection obtained with oocysts treated with acidified Hanks' balanced salt solution containing 1% trypsin. CC-QSD comparison of the C. parvum Iowa and TAMU isolates revealed significantly higher levels of infection for the TAMU isolate, which agrees with and supports previous human, animal, and cell culture studies. CC-QSD has the potential to aid in the optimization of Cryptosporidium cell culture methods and facilitate quantitative evaluation of cell culture infectivity experiments.     

A PCR-based molecular marker applicable for marker-assisted selection for anthracnose disease resistance in lupin breeding

Selection for anthracnose disease resistance is one of the major objectives in lupin breeding programs. The aim of this study was to develop a molecular marker linked to a gene conferring anthracnose resistance in narrow-leafed lupin (Lupinus angustifolius L.), which can be widely used for MAS in lupin breeding. A F(8)derived RIL population from a cross between cultivar Tanjil (resistant to anthracnose) and Unicrop (susceptible) was used for marker development. DNA fingerprinting was conducted on 12 representative plants by combining the AFLP method with primers designed based on conserved sequences of plant disease resistance genes. A co-dominant candidate marker was detected from a DNA fingerprint. The candidate marker was cloned, sequenced, and converted into a sequence-specific, simple PCR based marker. Linkage analysis based on a segregating population consisting of 184 RILs suggested that the marker, designated as AntjM2, is located 2.3 cM away from the R gene conferring anthracnose resistance in L. angustifolius. The marker has now being implemented for MAS in the Australian national lupin breeding program.     

Chemical genetics reveals a role for Mps1 kinase in kinetochore attachment during mitosis

Accurate chromosome segregation depends on proper assembly and function of the kinetochore and the mitotic spindle. In the budding yeast, Saccharomyces cerevisiae, the highly conserved protein kinase Mps1 has well-characterized roles in spindle pole body (SPB, yeast centrosome equivalent) duplication and the mitotic checkpoint. However, an additional role for Mps1 is suggested by phenotypes of MPS1 mutations that include genetic interactions with kinetochore mutations and meiotic chromosome segregation defects and also by the localization of Mps1 at the kinetochore, the latter being independent of checkpoint activation. We have developed a new MPS1 allele, mps1-as1, that renders the kinase specifically sensitive to a cell-permeable ATP analog inhibitor, allowing us to perform high-resolution execution point experiments that identify a novel role for Mps1 subsequent to SPB duplication. We demonstrate, by using both fixed- and live-cell fluoresence techniques, that cells lacking Mps1 function show severe defects in mitotic spindle formation, sister kinetochore positioning at metaphase, and chromosome segregation during anaphase. Taken together, our experiments are consistent with an important role for Mps1 at the kinetochore in mitotic spindle assembly and function.     

X-ray reflectivity studies of cPLA2{alpha}-C2 domains adsorbed onto Langmuir monolayers of SOPC

X-ray reflectivity is used to study the interaction of C2 domains of cytosolic phospholipase A(2) (cPLA(2)alpha-C2) with a Langmuir monolayer of 1-stearoyl-2-oleoyl-sn-glycero-3-phosphocholine (SOPC) supported on a buffered aqueous solution containing Ca(2+). The reflectivity is analyzed in terms of the known crystallographic structure of cPLA(2)alpha-C2 domains and a slab model representing the lipid layer to yield an electron density profile of the lipid layer and bound C2 domains. This new method of analysis determines the angular orientation and penetration depth of the cPLA(2)alpha-C2 domains bound to the SOPC monolayer, information not available from the standard slab model analysis of x-ray reflectivity. The best-fit orientation places the protein-bound Ca(2+) ions within 1 A of the lipid phosphate group (with an accuracy of +/-3 A). Hydrophobic residues of the calcium-binding loops CBL1 and CBL3 penetrate deepest into the lipid layer, with a 2 A penetration into the tailgroup region. X-ray measurements with and without the C2 domain indicate that there is a loss of electrons in the headgroup region of the lipid monolayer upon binding of the domains. We suggest that this is due to a loss of water molecules bound to the headgroup. Control experiments with a non-calcium buffer and with domain mutants confirm that the cPLA(2)alpha-C2 binding to the SOPC monolayer is Ca(2+)-dependent and that the hydrophobic residues in the calcium-binding loops are critical for membrane binding. These results indicate that an entropic component (due to water loss) as well as electrostatic and hydrophobic interactions contributes to the binding mechanism.     

Novel puroindoline and grain softness protein alleles in Aegilops species with the C, D, S, M and U genomes

DNA from six hexaploid, tetraploid and diploid species of Aegilops with the C, D, S, M and U genomes was amplified with specific PCR primers to identify sequences encoding puroindolines (Pins) a and b and grain softness protein (GSP), all of which are encoded by genes at the Ha (hardness) locus, with Ae. tauschii (DD) and bread wheat (T. aestivum) (AABBDD) cv Hiline being studied as controls. Seven new allelic forms of Pin a and Pin b were identified, including forms with mutations within or close to the tryptophan motif. In addition, five new forms of GSP were detected. In all species both genomic DNA from leaves and cDNA from developing grain were analysed. This revealed the presence of both silent genes (with premature stop codons) and multiple genes, with the latter being confirmed by Southern blot analysis. Freeze fracture analysis demonstrated that all except one accession (Ae. sharonensis) were soft textured. However, this difference cannot be accounted for by the sequences of the Pin alleles present in this line.