Chronic heart failure selectively induces regional heterogeneity of insulin-responsive glucose transporters

Glucose uptake across the sarcolemma is regulated by a family of membrane proteins called glucose transporters (GLUTs), which includes GLUT4 (the major cardiac isoform) and GLUT12 (a novel, second insulin-sensitive isoform). Potential regional patterns in glucose transport across the cardiac chambers have not been examined; thus, we hypothesized that insulin-responsive GLUT4 and -12 protein and gene expression would be chamber specific in healthy subjects and during chronic heart failure (HF). Using a canine model of tachypacing-induced, progressive, chronic HF, total GLUT protein and messenger RNA in both ventricles and atria (free wall and appendage) were investigated by immunoblotting and real-time PCR. In controls, GLUT4, but not GLUT12, protein content was significantly higher in the atria compared with the ventricles, with the highest content in the right atrium (RA; P < 0.001). GLUT4 and GLUT12 mRNA levels were similar across the cardiac chambers. During chronic HF, GLUT4 and GLUT12 protein content was highest in the left ventricle (LV; by 2.5- and 4.2-fold, respectively, P < 0.01), with a concomitant increase in GLUT4 and GLUT12 mRNA (P < 0.001). GLUT4, but not GLUT12, protein content was decreased in RA during chronic HF (P = 0.001). In conclusion, GLUT4 protein was differentially expressed across the chambers in the healthy heart, and this regional pattern was reversed during HF. Our data suggest that LV was the primary site dependent on both GLUT4 and GLUT12 during chronic HF. In addition, the paradoxical decrease in GLUT4 content in RA may induce perturbations in atrial energy production during chronic HF.     

Airway sizes and proportions in children quantified by a video-bronchoscopic technique

Background

Detecting serum antibody against inhaled antigens is an important diagnostic adjunct for hypersensitivity pneumonitis (HP). We sought to validate a quantitative fluorimetric assay testing serum from bird fanciers.

Methods

Antibody activity was assessed in bird fanciers and control subjects using various avian antigens and serological methods, and the titer was compared with symptoms of HP.

Results

IgG antibody against pigeon serum antigens, quantified by fluorimetry, provided a good discriminator of disease. Levels below 10 mg/L were insignificant, and increasing titers were associated with disease. The assay was unaffected by total IgG, autoantibodies and antibody to dietary hen's egg antigens. Antigens from pigeon serum seem sufficient to recognize immune sensitivity to most common pet avian species. Decreasing antibody titers confirmed antigen avoidance.

Conclusion

Increasing antibody titer reflected the likelihood of HP, and decreasing titers confirmed antigen avoidance. Quantifying antibody was rapid and the increased sensitivity will improve the rate of false-negative reporting and obviate the need for invasive diagnostic procedures. Automated fluorimetry provides a method for the international standardization of HP serology thereby improving quality control and improving its suitability as a diagnostic adjunct.     

Enhancement of endothelial cell migration and in vitro tube formation by TAP20, a novel beta 5 integrin-modulating, PKC theta-dependent protein

Migration, proliferation, and tube formation of endothelial cells are regulated by a protein kinase C isoenzyme PKCtheta. A full-length cDNA encoding a novel 20-kD protein, whose expression was PKCtheta-dependent, was identified in endothelial cells, cloned, characterized, and designated as theta-associated protein (TAP) 20. Overexpression of TAP20 decreased cell adhesion and enhanced migration on vitronectin and tube formation in three-dimensional culture. An antiintegrin alphavbeta5 antibody prevented these TAP20 effects. Overexpression of TAP20 also decreased focal adhesion formation in alphavbeta3-deficient cells. The interaction between TAP20 and beta5 integrin cytoplasmic domain was demonstrated by protein coprecipitation and immunoblotting. Thus, the discovery of TAP20, which interacts with integrin beta5 and modulates cell adhesion, migration, and tube formation, further defines a possible pathway to angiogenesis dependent on PKCtheta.     

Alterations of the electrophoretic mobility distribution of rat mast cells after immunologic activation.

Changes in the electrophoretic mobility distributions of rat serosal mast cells after immunologic activation have been measured using the laser Doppler technique of electrophoretic light scattering. Rat serosal mast cells of 98% purity isolated by isopycnic and velocity gradient sedimentation had a highly negative electrophoretic mobility which was unaffected by incubation with normal rabbit serum or, at 4 degrees C or in the absence of Ca+2, with rabbit anti-rat E(ab')2 antiserum. Immunologic activation of the cells with this antiserum in the presence of Ca+2 at 37 degrees C resulted in a dose- and time-dependent increase in the electrophoretic mobility. Thus at a 1:25 dilution of anti-F(ab')2 the mean and mode electrophoretic mobilities of the mast cell population increased 25 and 21%, respectively. The width of the electrophoretic mobility distribution also increased with activation, indicating a heterogeneous response of the mast cells in the population. The increase in electrophoretic mobility after immunologic activation is not diminished by treatment of the cells with 1 M NaCl to solubilize adsorbed mast cell granule or heparin.     

N-alkylated cyclen cobalt(III) complexes of 1-(chloromethyl)-3-(5,6,7-trimethoxyindol-2-ylcarbonyl)-2,3-dihydro-1H-pyrrolo[3,2-f]quinolin-5-ol DNA alkylating agent as hypoxia-activated prodrugs

A series of cobalt complexes of the potent DNA minor groove alkylator 1-(chloromethyl)-3-(5,6,7-trimethoxyindol-2-ylcarbonyl)-2,3-dihydro-1H-pyrrolo[3,2-f]quinolin-5-ol (seco-6-azaCBI-TMI) were prepared from a series of N-substituted cyclen ligands. The final N-substituted complexes carried formal overall charges ranging from +2 to -2 and showed limited improvements in solubility. They showed similar stabilities to that of the complex with the unsubstituted cyclen ligand, and large but variable attenuation of the cytotoxicity of the free alkylator (2-30-fold), compared to 150-fold for the unsubstituted ligand. However, they had oxic/hypoxic ratios (2-22-fold) comparable to that of the unsubstituted cyclen complex (5).     

Influence of certain soil factors on chocolate spot of beans

In the summer of 1941 chocolate spot of beans was widespread in the South-Eastern Agricultural Province and caused much damage to the crop. Soil samples were collected from forty-nine affected fields on a variety of soil types, and the relation between the severity of attack by chocolate spot and the texture, pH, available potassium and available phosphorus determined. Severity of attack was classified into three grades: 'slight', in which only spotting of the foliage occurred; 'moderate', in which death of leaves and blossoms on the three or four lowest nodes occurred; and 'severe', in which there was generally a total loss of crop. No significant relation between severity of attack and soil texture, pH or available potassium was found. A highly significant relation was found to exist between the severity of attack and the amount of available phosphorus in the soil as determined by the method of soil analysis used in this Province. Damage by chocolate spot was generally slight on soils containing 'medium to medium high' or higher amounts of available phosphorus, and generally severe on soils containing low amounts of available phosphorus.     

Classification tree method for bacterial source tracking with antibiotic resistance analysis data

Various statistical classification methods, including discriminant analysis, logistic regression, and cluster analysis, have been used with antibiotic resistance analysis (ARA) data to construct models for bacterial source tracking (BST). We applied the statistical method known as classification trees to build a model for BST for the Anacostia Watershed in Maryland. Classification trees have more flexibility than other statistical classification approaches based on standard statistical methods to accommodate complex interactions among ARA variables. This article describes the use of classification trees for BST and includes discussion of its principal parameters and features. Anacostia Watershed ARA data are used to illustrate the application of classification trees, and we report the BST results for the watershed.     

Evidence of mTOR Activation by an AKT-Independent Mechanism Provides Support for the Combined Treatment of PTEN-Deficient Prostate Tumors with mTOR and AKT Inhibitors

Activation of the phosphoinositide 3-kinase pathway is commonly observed in human prostate cancer. Loss of function of phosphatase and tensin homolog (PTEN) is associated with the activation of AKT and mammalian target of rapamycin (mTOR) in many cancer cell lines as well as in other model systems. However, activation of mTOR is also dependent of kinases other than AKT. Here, we show that activation of mTOR is not dependent on AKT in a prostate-specific PTEN-deficient mouse model of prostate cancer. Pathway bifurcation of AKT and mTOR was noted in both mouse and human prostate tumors. We demonstrated for the first time that cotargeting mTOR and AKT with ridaforolimus/MK-8669 and M1K-2206, respectively, delivers additive antitumor effects in vivo when compared to single agents. Our preclinical data suggest that the combination of AKT and mTOR inhibitors might be more effective in treating prostate cancer patients than current treatment regimens or either treatment alone.