Antioxidant mechanisms of polyphenolic caffeic acid oligomers, constituents of Salvia officinalis

Caffeic acid, rosmarinic acid and oligomers of caffeic acid with multiple catechol groups are all constituents of Salvia officinalis. Their antioxidant potential was investigated with regard to their radical scavenging activity and the stability and structure of the intermediate radicals. Pulse-radiolytic studies revealed very high rate constants with hydroxyl radicals. Evidence from kinetic modeling calculations suggested an unusual complex behavior due to the presence of both O4- and O3-semiquinones and formation and decay of a hydroxyl radical adduct at the vinyl side chain. The radical structures observed by EPR spectroscopy after autoxidation in slightly alkaline solutions were only partially identified due to their instability and generally represented dissociated O4-semiquinones. Hybrid density-functional calculations of the potential radical structures showed distinct differences between the resonance stabilization of the O4- and O3-semiquinones of caffeic and dihydrocaffeic acids, reflected also in the considerably faster decay of the O3-semiquinone observed by pulse radiolysis. No evidence was found for dimerization reactions via Cbeta radicals typical for lignin biosynthesis.     

Recognition and treatment of bladder outlet obstruction after sling surgery

At the University of Pittsburgh School of Medicine, our experience with urethrolysis over the past several years offered a unique opportunity to assess outcomes after delayed time to urethrolysis. We observed a highly suggestive association between prolonged time to urethrolysis and a greater likelihood of persistent bladder dysfunction. If this observation is corroborated by other studies, it would be prudent to lower our threshold of clinical suspicion to detect bladder outlet obstruction. Videourodynamics testing can be invaluable for making the distinction between outlet obstruction versus de novo urge incontinence. Here, we briefly review the literature on urethrolysis and present the urethrolysis technique utilized at our institution. The article concludes with several challenging and controversial clinical judgment questions asked ofDr Leng by Dr Chancellor.     

Old drugs as lead compounds for a new disease? Binding analysis of SARS coronavirus main proteinase with HIV, psychotic and parasite drugs

The SARS-associated coronavirus (SARS-CoV) main proteinase is a key enzyme in viral polyprotein processing. To allow structure-based design of drugs directed at SARS-CoV main proteinase, we predicted its binding pockets and affinities with existing HIV, psychotic and parasite drugs (lopinavir, ritonavir, niclosamide and promazine), which show signs of inhibiting the replication of SARS-CoV. Our results suggest that these drugs and another two HIV inhibitors (PNU and UC2) could be used as templates for designing SARS-CoV proteinase inhibitors.     

Analysis of part of the<Emphasis Type="Italic">Trichophyton rubrum</Emphasis> ESTs

Trichophyton rubrum (T. rubrum) is the most common of the superficial fungi. In an effort to better understand the genetic and biochemical makeup ofT. rubrum, we generated cDNA libraries from 3 growth stages and used these to isolate 4002 unique expressed sequence tags (ESTs). Sequence comparisons with the Genbank database allowed 1226 of the ESTs to be assigned putative functions or matched with homologs from other organisms. Of the remaining ESTs, 989 were only weakly similar to known sequences and 1787 had no identifiable functions, suggesting that they represent novel genes. We further analyzed the presence of several important genes involved in the growth, metabolism, signal transduction, pathogenesis and drug resistance inT. rubrum. This information was used to newly elucidate important metabolic pathways inT. rubrum. Taken together, our results should form the molecular basis for continued research on the physiological processes and pathogenic mechanisms ofT. rubrum, and may lead to a better understanding of fungal drug resistance and identification of new drug targets.     

A unique set of 11,008 onion expressed sequence tags reveals expressed sequence and genomic differences between the monocot orders Asparagales and Poales

Enormous genomic resources have been developed for plants in the monocot order Poales; however, it is not clear how representative the Poales are for the monocots as a whole. The Asparagales are a monophyletic order sister to the lineage carrying the Poales and possess economically important plants such as asparagus, garlic, and onion. To assess the genomic differences between the Asparagales and Poales, we generated 11,008 unique ESTs from a normalized cDNA library of onion. Sequence analyses of these ESTs revealed microsatellite markers, single nucleotide polymorphisms, and homologs of transposable elements. Mean nucleotide similarity between rice and the Asparagales was 78% across coding regions. Expressed sequence and genomic comparisons revealed strong differences between the Asparagales and Poales for codon usage and mean GC content, GC distribution, and relative GC content at each codon position, indicating that genomic characteristics are not uniform across the monocots. The Asparagales were more similar to eudicots than to the Poales for these genomic characteristics.     

BPGAP1 interacts with cortactin and facilitates its translocation to cell periphery for enhanced cell migration

Rho GTPases control cell dynamics during growth and development. They are activated by guanine nucleotide exchange factors and inactivated by GTPase-activating proteins (GAPs). Many GAPs exist with various protein modules, the functions of which largely remain unknown. We recently cloned and identified BPGAP1 as a novel RhoGAP that coordinately regulates pseudopodia and cell migration via the interplay of its BNIP-2 and Cdc42GAP homology, RhoGAP, and the proline-rich domains. To further elucidate the molecular mechanism underlying cell dynamics control by BPGAP1, we used protein precipitations and matrix-assisted laser desorption/ionization mass spectrometry and identified cortactin, a cortical actin binding protein as a novel partner of BPGAP1 both in vitro and in vivo. Progressive deletion studies confirmed that cortactin interacted directly and constitutively with the proline-rich motif 182-PPPRPPLP-189 of BPGAP1 via its Src homology 3 domain. Together, they colocalized to periphery and enhanced cell migration. Furthermore, substitution of prolines at 184 and 186 with alanines abolished their interaction. Consequently, this BPGAP1 mutant failed to facilitate translocation of cortactin to the periphery, and no enhanced cell migration was observed. These results provide the first evidence that a RhoGAP functionally interacts with cortactin and represents a novel determinant in the regulation of cell dynamics.     

CD4+CD25+ regulatory T cells suppress differentiation and functions of Th1 and Th2 cells,Leishmania major infection,and colitis in mice

Regulatory T cells play a major role in modulating the immune response. However, most information on these cells centers on autoimmunity, and there is also considerable controversy on the functional characteristics of these cells. Here we provide direct in vitro and in vivo evidence that CD4+CD25+ regulatory T cells inhibit the differentiation and functions of both Th1 and Th2 cells. Importantly, CD4+CD25+ T cells suppressed the disease development of Leishmania major infection in SCID mice reconstituted with naive CD4+CD25- T cells. Furthermore, CD4+CD25+ T cells inhibited the development of colitis induced by both Th1 and Th2 cells in SCID mice. Our results therefore document that CD4+CD25+ regulatory T cells suppress both Th1 and Th2 cells and that these regulatory T cells have a profound therapeutic potential against diseases induced by both Th1 and Th2 cells in vivo.     

Chinese phlebotomine sandflies of subgenus Adlerius nitzulescu, 1931 (Diptera: Psychodidae) and the identity of Phlebotomus sichuanensis Leng & Yin, 1983. Part I--Taxonomical study and geographical distribution

Four species of Adlerius phlebotomine sandflies have been recorded in China, namely: P. chinensis Newstead, 1916 (Pc), P. fengi Leng & Zhang, 1994; P. longiductus Parrot, 1928 and P. sichuanensis Leng & Yin, 1983 (Ps). Adlerius phlebotomies are the main vectors of visceral leishmaniasis (VL) in China; three of them are acknowledged as VL vectors and P. fengi is considered a potential VL vector for southwestern mountainous region. Different opinion has been raised to the validity of identity of Ps by some investigators from Shanghai and Shanxi who consider Ps to be a large type of Pc instead of an isolate species. The center of controversy is whether Ps is an isolate taxon or a large type of Pc. The present authors have carried out a series of comparative studies for these two flies on: 1 quantitative and qualitative morphological characters of four Chinese Adlerius phlebotomies; and 2. differences in geographical distribution. All specimens of Pc and Ps used in the present study are collected where their holotypes-paratypes were produced--West Mountain, West Suburb, Beijing and Lixian County, Sichuan Province. The results have forcefully proved that Ps is an isolate species instead of a so-called large type Pc according to the concept of species. The clarification of their taxonomical identities is meaningful because both of them are VL vectors in different epidemic areas in China; especially Ps is an important VL vector in high mountainous regions of southwestern China and some extend to the Loess Plateau of northwestern China, where VL still exists and it is also the first Phlebotomine sandfly discovered in Tibet, the locality being near Assam in India (Leng et al. 1990).     

RESOURCERER: a database for annotating and linking microarray resources within and across species

Microarray expression analysis is providing unprecedented data on gene expression in humans and mammalian model systems. Although such studies provide a tremendous resource for understanding human disease states, one of the significant challenges is cross-referencing the data derived from different species, across diverse expression analysis platforms, in order to properly derive inferences regarding gene expression and disease state. To address this problem, we have developed RESOURCERER, a microarray-resource annotation and cross-reference database built using the analysis of expressed sequence tags (ESTs) and gene sequences provided by the TIGR Gene Index (TGI) and TIGR Orthologous Gene Alignment (TOGA) databases [now called Eukaryotic Gene Orthologs (EGO)].