Divergent effects of cyanate on amino acid and phosphate uptake by liver and hepatoma.

The uptake of alpha-aminoiso[3H]butyric acid and 32Pi was observed to be inhibited by sodium cyanate in transplanted hepatomas but was increased in the livers of the tumor bearing rats. Incorporation of 32Pi into macromolecules in hepatomas was also inhibited by cyanate. Treatment with this drug did not influence circulating concentrations of isotope-labeled materials. There were relatively small effects on uptake of 36Cl- in cyanate-treated rats and the action was not tissue specific. The data were compatible with an inhibitory effect of cyanate on active transport in hepatomas which was not seen under the same conditions in host liver.     

The use of microwave oven for the rapid hydrolysis of bile acid methyl esters.

An efficient and convenient procedure for the hydrolysis of bile acid methyl esters is described. This is achieved by the addition of aqueous lithium hydroxide in methanol/dioxane/tetrahydrofuran (or dimethylformamide) in the microwave oven. Under these conditions the formates as well as the acetate derivatives prepared under microwave irradiation conditions were also hydrolyzed, and the desired bile acids were isolated in 86-94% yield. All these reactions were completed in the microwave oven within 45-60 s.     

C26-analogs of naturally occurring bile alcohols-II. Preparation of 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,23-tetrols (23R and 23S) and 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,26-tetrols (25R and 25S) by a hydroboration procedure

A convenient procedure for the synthesis of 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,23-tetrol (23R and 23S) and 24-nor-5 beta-cholestane-3 alpha,7 alpha,12alpha,26-tetrol (25R and 25S) starting from 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,25-tetrol was developed. Dehydration of 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha, 25-tetrol with glacial acetic acid and acetic anhydride yielded a mixture of 24-nor-5 beta-cholest-23-ene-3 alpha,7 alpha,12 alpha-triol and the corresponding delta 25 compound. Hydroboration and oxidation of the mixture of unsaturated nor-triols resulted in the formation of 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,23-tetrols (23R and 23S) and 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,26-tetrols (25R and 25S). In addition, smaller amounts of 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha,22 xi-tetrol and 24-nor-5 beta-cholestane-3 alpha,7 alpha,12 alpha-triol were also obtained. The C26 bile alcohols epimeric at C-23 and C-25 were resolved by analytical and preparative TLC and characterized by gas-liquid chromatography and mass spectrometry. Provisional assignment of the configurations of the C-23 and C-25 hydroxyl groups were made on the basis of molecular rotation differences. These C26 alcohols will be used to test the stereospecificity of the hepatic enzymes that promote oxidation of the cholesterol side chain.     

Increasing reproducibility,robustness, and generalizability of biomarker selection from meta-analysis using Bayesian methodology

A major limitation of gene expression biomarker studies is that they are not reproducible as they simply do not generalize to larger, real-world, heterogeneous populations. Frequentist multi-cohort gene expression meta-analysis has been frequently used as a solution to this problem to identify biomarkers that are truly differentially expressed. However, the frequentist meta-analysis framework has its limitations–it needs at least 4–5 datasets with hundreds of samples, is prone to confounding from outliers and relies on multiple-hypothesis corrected p-values. To address these shortcomings, we have created a Bayesian meta-analysis framework for the analysis of gene expression data. Using real-world data from three different diseases, we show that the Bayesian method is more robust to outliers, creates more informative estimates of between-study heterogeneity, reduces the number of false positive and false negative biomarkers and selects more generalizable biomarkers with less data. We have compared the Bayesian framework to a previously published frequentist framework and have developed a publicly available R package for use.     

Murine macrophage inflammatory cytokine production and immune activation in response to Vibrio parahaemolyticus infection

Vibrio parahaemolyticus is the most common cause of bacterial, seafood‐related illness in the USA. Currently, there is a dearth of published reports regarding immunity to infection with this pathogen. Here, production of both pro‐ and anti‐inflammatory cytokines by V. parahaemolyticus‐infected RAW 264.7 murine macrophages was studied. It was determined that this infection results in increased concentrations of IL‐1α, IL‐6, TNF‐α and IL‐10. Additionally, decreases in cell surface TLR2 and TLR4 and increases in T‐cell co‐stimulatory molecules CD40 and CD86 were discovered. The data presented here begin to identify the immune variables required to eliminate V. parahaemolyticus from infected host tissues.     

Characterization and physical mapping of ribosomal RNA gene families in Plantago

• Background and Aims The organization of rRNA genes incultivated Plantago ovata Forsk. and several of its wild allieswas analysed to gain insight into the phylogenetic relationshipsof these species in the genus which includes some 200 species. • Methods Specific primers were designed to amplify theinternal transcribed spacer (ITS1 and ITS2) regions from sevenPlantago species and the resulting fragments were cloned andsequenced. Similarly, using specific primers, the 5S rRNA genesfrom these species were amplified and subsequently cloned. Fluorescencein-situ hybridization (FISH) was used for physical mapping of5S and 45S ribosomal RNA genes. • Results The ITS1 region is 19–29 bp longer thanthe ITS2 in different Plantago species. The 5S rRNA gene-repeatingunit varies in length from 289 to 581 bp. Coding regions arehighly conserved across species, but the non-transcribed spacers(NTS) do not match any database sequences. The clone from thecultivated species P. ovata was used for physical mapping ofthese genes by FISH. Four species have one FISH site while threehave two FISH sites. In P. lanceolata and P. rhodosperma, the5S and 45S (18S-5·8S-25S) sites are coupled. • Conclusions Characterization of 5S and 45S rRNA geneshas indicated a possible origin of P. ovata, the only cultivatedspecies of the genus and also the only species with x = 4, froma species belonging to subgenus Psyllium. Based on the studiesreported here, P. ovata is closest to P. arenaria, althoughon the basis of other data the two species have been placedin different subgenera. FISH mapping can be used as an efficienttool to help determine phylogenetic relationships in the genusPlantago and show the interrelationship between P. lanceolataand P. lagopus.