Glycoprotein reductions in the adipocyte cytoplasmic membrane from obese Zucker rats

The adipocyte cytoplasmic membranes from lean and obese Zucker rats were analyzed. A reduction in the galactose-containing glycoproteins was demonstrated from adipocyte cytoplasmic membranes of obese rats. A compensatory increase was observed in several membrane proteins which did not contain carbohydrate. This reduction was observed in obese rats at 5 and 16 weeks old.     

Glucose-based spiro-isoxazolines: A new family of potent glycogen phosphorylase inhibitors

A series of glucopyranosylidene-spiro-isoxazolines was prepared through regio- and stereoselective [3+2]-cycloaddition between the methylene acetylated exo-glucal and aromatic nitrile oxides. The deprotected cycloadducts were evaluated as inhibitors of muscle glycogen phosphorylase b. The carbohydrate-based family of five inhibitors displays K_i values ranging from 0.63 to 92.5 μM. The X-ray structures of the enzyme–ligand complexes show that the inhibitors bind preferentially at the catalytic site of the enzyme retaining the less active T-state conformation. Docking calculations with GLIDE in extra-precision (XP) mode yielded excellent agreement with experiment, as judged by comparison of the predicted binding modes of the five ligands with the crystallographic conformations and the good correlation between the docking scores and the experimental free binding energies. Use of docking constraints on the well-defined positions of the glucopyranose moiety in the catalytic site and redocking of GLIDE-XP poses using electrostatic potential fit-determined ligand partial charges in quantum polarized ligand docking (QPLD) produced the best results in this regard.     

Courtship Behavior of Zaprionus indianus (Gupta) (Diptera: Drosophilidae) from Populations Colonizing South America

We describe for the first time the sexual behavior and the courtship song of males of the African fly Zaprionus indianus (Gupta), a recent invader of South America. The male courtship song is formed by monocyclic pulses and the courtship behavior is simple when compared to that of species of Drosophila. Two interpulse interval (IPI) distributions were observed: pre-mounting and mounting. No significant difference was observed between the pre-mounting IPIs of males that descended from three geographical populations from South America. We also observed the songs produced by females and the homosexual behavior exhibited by males. A sequence of bursts is produced by females as a refusal signal against males, while males emit a characteristic song that identifies sex genus, which differs from the courtship song. The short courtship and mating latencies recorded reveal vigorous males and receptive females, respectively.     

Organization and evolution of the alcohol dehydrogenase gene in Drosophila

The alcohol dehydrogenase (Adh) gene was isolated from Drosophila simulans and D. mauritiana, and the DNA sequence of a 4.6-kb region, containing the structural gene and flanking sequence, was determined for each. These sequences were compared with the Adh region of D. melanogaster to characterize changes that occur in the Drosophila genome during evolution and to identify conserved sequences of functional importance. Drosophila simulans and D. mauritiana Adh are organized in a manner similar to that of D. melanogaster Adh, including the presence of two promoters for the single Adh gene. This study identified conserved flanking elements that, in conjunction with other studies, suggest regions that may be involved in the control of Adh expression. Inter- and intraspecies comparisons revealed differences in the kinds of sequence changes that have accumulated. Sequence divergence in and around the Adh gene was used to assess inter- and intraspecies evolutionary relationships. Finally, there appears to be an unrelated structural gene located directly 3' of the Adh transcribed region.      

Influenza A viruses in American White Pelican (Pelecanus erythrorhynchos)

The role of many wild waterbird species in the ecology and epidemiology of avian influenza viruses (AIV) remains unclear. We report the first isolation of AIV from American White Pelicans (Pelecanus erythrorhynchos; Pelecaniformes) in North America. Two H13N9 AIVs were isolated from hatchling birds in breeding colonies in Minnesota, USA, during 2007 and 2008. Based on molecular sequencing of the hemagglutinin and neuraminidase genes, the 2008 virus was genetically related to AIVs previously isolated from gulls and shorebirds in North America. The 2007 isolate was most related to AIVs from Eurasian gulls and North American ducks, reflecting both global movement of these viruses and reassortment between viruses associated with duck and gull reservoirs.     

Detection of avian influenza viruses from shorebirds: evaluation of surveillance and testing approaches

Although influenza A viruses have been isolated from numerous shorebird species (Family: Scolopacidae) worldwide, our understanding of natural history of these viruses in this diverse group is incomplete. Gaining this information can be complicated by sampling difficulties related to live capture, the need for large sample sizes related to a potentially low prevalence of infection, and the need to maintain flexibility in diagnostic approaches related to varied capabilities and resources. To provide information relevant to improving sampling and testing of shorebirds for influenza A viruses, we retrospectively evaluated a combined data set from Delaware Bay, USA, collected from 2000 to 2009. Our results indicate that prevalence trends and subtype diversity can be effectively determined by either direct sampling of birds or indirect sampling of feces; however, the extent of detected subtype diversity is a function of the number of viruses recovered during that year. Even in cases where a large number of viruses are identified, an underestimate of true subtype diversity is likely. Influenza A virus isolation from Ruddy Turnstones can be enhanced by testing both cloacal and tracheal samples, and matrix real-time PCR can be used as an effective screening tool. Serologic testing to target species of interest also has application to shorebird surveillance. Overall, all of the sampling and diagnostic approaches have utility as applied to shorebird surveillance, but all are associated with inherent biases that need to be considered when comparing results from independent studies.     

Antagonistic effects of the SRp30c protein and cryptic 5' splice sites on the alternative splicing of the apoptotic regulator Bcl-x

Alternative 5' splice site selection allows Bcl-x to produce two isoforms with opposite effects on apoptosis. The pro-apoptotic Bcl-x(S) variant is up-regulated by ceramide and down-regulated by protein kinase C through specific cis-acting exonic elements, one of which is bound by SAP155. Splicing to the Bcl-x(S) 5' splice site is also enforced by heterogeneous nuclear ribonucleoprotein (hnRNP) F/H proteins and by Sam68 in cooperation with hnRNP A1. Here, we have characterized exon elements that influence splicing to the 5' splice site of the anti-apoptotic Bcl-x(L) isoform. Within a 86-nucleotide region (B3) located immediately upstream of the Bcl-x(L) donor site we have identified two elements (ML2 and AM2) that stimulate splicing to the Bcl-x(L) 5' splice site. SRp30c binds to these elements and can shift splicing to the 5' splice site of Bcl-x(L) in an ML2/AM2-dependent manner in vitro and in vivo. The B3 region also contains an element that represses the use of Bcl-x(L). This element is bound by U1 small nuclear ribonucleoprotein and contains two 5' splice sites that can be used when the Bcl-x(L) 5' splice site is mutated or the ML2/AM2 elements are deleted. Conversely, mutating the cryptic 5' splice sites stimulates splicing to the Bcl-x(L) site. Thus, SRp30c stimulates splicing to the downstream 5' splice site of Bcl-x(L), thereby attenuating the repressive effect of upstream U1 snRNP binding sites.     

A new technique for staining mast cells using ferroin

We describe here a new method for specific staining of mast cells using ferroin. Different hamster tissues were fixed in 4% formalin and processed for paraffin embedding. Sections were stained with hematoxylin followed by ferroin acidified with 2.5 N sulfuric acid to pH 4.0. Mast cells stained an intense orange color that contrasted markedly with bluish violet nuclei. High contrast was also observed when ferroin colored sections were counterstained with light green instead of hematoxylin. To evaluate the specificity of the stain, hamster cheek pouch sections were stained with toluidine blue, alcian blue-safranin O, and ferroin. Quantitative evaluation of mast cells stained with the three techniques showed no statistical difference. The simplicity and selectivity of this method is sufficient for image analysis of mast cells.