Spatial Distribution of Helicobacter spp. in the Gastrointestinal Tract of Dogs

Background:  In dogs, the gastric Helicobacter spp. have been well studied, but there is little information regarding the other parts of the alimentary system. We sought to determine the spatial distribution of Helicobacter spp. in the gastrointestinal tract and the hepatobiliary system of dogs using culture-independent methods.
Materials and methods:  Samples of stomach, duodenum, ileum, cecum, colon, pancreas, liver, and bile from six dogs were evaluated for Helicobacter spp. by genus, gastric, and enterohepatic Helicobacter spp. Polymerase chain reaction, 16S rRNA gene sequence analysis, immunohistochemistry, and fluorescence in situ hybridization (FISH).
Results:  In the stomach, Helicobacter spp. DNA was detected in all six dogs, with H. bizzozeronii and H. felis identified by specific polymerase chain reaction. Helicobacter organisms were localized within the surface mucus, the lumen of gastric glands, and inside parietal cells. The small intestine harbored gastric and enterohepatic Helicobacter spp. DNA/antigen in low amounts. In the cecum and colon, Helicobacter spp. DNA, with highest similarity to H. bilis /flexispira taxon 8, H. cinaedi , and H. canis, was detected in all six dogs. Helicobacter organisms were localized at the mucosal surface and within the crypts. Gastric Helicobacter spp. DNA was detected occasionally in the large intestine, but no gastric Helicobacter spp. were present in clone libraries or detected by FISH.
Conclusions:  This study demonstrates that in addition to the stomach, the large intestine of dogs is also abundantly colonized by Helicobacter spp. Additional studies are necessary to investigate the association between enterohepatic Helicobacter spp. and presence of intestinal inflammatory or proliferative disorders in dogs.     

Whole-cell biocatalysis: Evaluation of new hydrophobic ionic liquids for efficient asymmetric reduction of prochiral ketones

A biphasic process design is often applied in whole-cell biocatalysis if substrate and product have low water solubility, are unstable in water or toxic for the biocatalyst. Some water immiscible ionic liquids (ILs) with adequate distribution coefficients have already been applied successfully as second liquid phase, which acts as a substrate reservoir and in situ extractant for the product. In this work, 12 new ILs were evaluated with respect to their applicability in biphasic asymmetric reductions of prochiral ketones in comparison to 9 already published ILs. The ILs under study are composed of seven different cations and three different anions. Recombinant Escherichia coli was used as whole-cell biocatalyst overexpressing the genes of a Lactobacillus brevis alcohol dehydrogenase (LB-ADH) and a Candida boidinii formate dehydrogenase (CB-FDH) for cofactor regeneration. Best results were achieved if ionic liquids with [PF6]- and [NTF]-anions were applied, whereas [FAP]-ILs showed minor qualification, e.g., the use of [HMPL][NTF] as second liquid phase for asymmetric synthesis of (R)-2-octanol resulted in a space–time-yield of 180 g L⁻¹ d⁻¹, a chemical yield of 95% and an enantiomeric excess of 99.7% in a simple batch process.     

Toddler formula supplemented with docosahexaenoic acid (DHA) improves DHA status and respiratory health in a randomized,double-blind,controlled trial of US children less than 3 years of age

Studies of docosahexaenoic acid (DHA) intake and status in US toddlers are lacking. One national survey found low DHA intakes. The objectives of this double-blind, randomized study were to (a) determine usual DHA intakes, (b) measure the effect of consuming formulas with DHA on red blood cell (RBC) and plasma DHA and (c) record adverse events in US children between 18 and 36 months of age. Children aged 18–36 months were provided 237-ml formula with 0, 43, or 130 mg DHA per day for 60 days. Blood was obtained at 0 and 60 days and 24-hour dietary recalls at 0, 30 and 60 days. Usual median daily DHA intake was 13.3 mg. RBC DHA increased in a dose-dependent manner with increasing DHA intake (p<0.05). Toddlers consuming the formula with 130 mg DHA per day have fewer adverse events (p=0.007) and a lower incidence of respiratory illness (p=0.024), compared to the formula without DHA. US toddlers have low DHA intake and status. Modest increases in DHA intake in toddlers might improve development, including respiratory health.     

Detection of a non-structural protein of M r 11 000 encoded by the virion DNA of maize streak virus

A polypeptide of approximately 11 000 daltons (11 kDa protein) encoded by an open reading frame (10.9 ORF) from the virion sense of maize streak virus (MSV) DNA has been detected among the products of in vitro translation reactions programmed with RNA from infected maize plants and also in total protein extracts from infected leaves. The 11 kDa protein has not been detected in virions and is therefore proposed to have a nonstructural role.Viral DNA with an additional in-frame translation stop codon in the 10.9 ORF was not infectious when transmitted to maize plants via Agrobacterium tumefaciens agroinfection, suggesting that the 10.9 ORF may be essential for virus function. Computer comparison data show that equivalent ORFs in wheat dwarf virus (WDV) and digitaria streak virus (DSV) have some sequences in common with the 10.9 ORF of MSV. Further-more, the absence of similar sequences in geminiviruses which infect dicotyledonous plants suggests that the 11 kDa protein and its putative homologs in WDV and DSV have a function necessary only for those geminiviruses which infect the Gramineae.The significance of the 11 kDa protein in relation to expression of the virion sense DNA of MSV is discussed.     

The Wnt signaling regulator R-spondin 3 promotes angioblast and vascular development

The vertebrate embryonic vasculature develops from angioblasts, which are specified from mesodermal precursors and develop in close association with blood cells. The signals that regulate embryonic vasculogenesis and angiogenesis are incompletely understood. Here, we show that R-spondin 3 (Rspo3), a member of a novel family of secreted proteins in vertebrates that activate Wnt/beta-catenin signaling, plays a key role in these processes. In Xenopus embryos, morpholino antisense knockdown of Rspo3 induces vascular defects because Rspo3 is essential for regulating the balance between angioblast and blood cell specification. In mice, targeted disruption of Rspo3 leads to embryonic lethality caused by vascular defects. Specifically in the placenta, remodeling of the vascular plexus is impaired. In human endothelial cells, R-spondin signaling promotes proliferation and sprouting angiogenesis in vitro, indicating that Rspo3 can regulate endothelial cells directly. We show that vascular endothelial growth factor is an immediate early response gene and a mediator of R-spondin signaling. The results identify Rspo3 as a novel, evolutionarily conserved angiogenic factor in embryogenesis.     

Cultured peritoneal mesothelial cells exhibit apical primary cilia

This study examined primary cilia on cultured human and rabbit peritoneal mesothelial cells (PMC) and investigated factors that influence ciliary expression. Primary cilia were examined with indirect immunocytochemistry, laser scanning confocal microscopy and scanning electron microscopy. Ciliary expression was evaluated in cultures with or without l-cysteine (0.25 mM) or exposure to Ca(2+)-free Krebs-Ringer solution supplemented with EGTA, 0.5 mM. This treatment disrupted cell monolayer integrity. Cilia were counted and normalized to total cell counts using NIH image. Primary cilia were identified on both human and rabbit PMC. Cells treated with l-cysteine expressed significantly more cilia compared with monolayers deprived of l-cysteine. Exposure to Ca(2+)-free Krebs-Ringer solution significantly reduced cilia (5.9+/-1.0%, n=7). Although ciliary expression could be augmented with l-cysteine, approximately 60% of human PMC and 84% of rabbit PMC did not exhibit cilia. Together, these data show that monolayers of PMC express apical cilia that can be augmented with l-cysteine, independently of increased cell density.