bluuebunny/crossref_metadata_2025 huggingface dataset:
OPTIMAL MONETARY POLICY AND ASSET PRICE MISALIGNMENTS
Authors: Kontonikas Alexandros , Montagnoli Alberto
Published: October 2006

This paper analyses the relationship between monetary policy and asset prices in the context of optimal policy rules. The transmission mechanism is represented by a linearized rational expectations model augmented for the effect of asset prices on aggregate demand. Stabilization objectives are represented by a discounted quadratic loss function penalizing inflation and output gap volatility. Asset prices are allowed to deviate from their intrinsic value due to momentum trading. We find that in the presence of wealth effects and inefficient markets, asset price misalignments from their fundamentals should be included in the optimal interest rate reaction function.
Integrativeness: untenable for world Englishes learners?
Authors: COETZEE‐VAN ROOY SUSAN
Published: October 2006

ABSTRACT:  Kachru (1988) and Sridhar and Sridhar (1992) argue that the spread of English as a world language increases the types of context in which English is learnt today. The sociolinguistic realities of world Englishes learners today challenge the validity of some second‐language acquisition theories. One of the theoretical limitations of existing second‐language acquisition theories is the dependence upon the notion of integrativeness to explain success in second‐language acquisition. In this paper, the notion of integrativeness is problematized from an empirical and theoretical perspective. The main findings are: (1) second‐language acquisition theories that rely on any assumption of integrativeness should not be applied uncritically to sociolinguistic contexts where learners are acquiring a variety of world English today; (2) it seems that the concentric circle description of the sociolinguistic realities of world Englishes speakers needs to be adjusted.
A different paradigm for expert systems: an introduction to logic programming and related knowledge representation issues
Authors: Jones James D.
Published: October 2006

Abstract: Current expert system technology is 30 years old. Expert system shells find their origins in the work of early expert systems, most notably MYCIN which was developed at Stanford in the mid‐1970s. Even Prolog programmers are settling for less robust reasoning power. The logic programming community (from which both expert systems and Prolog arose) has made notable advances since those times. These advances are lacking from current expert system technology. The advances include a well‐developed theory of multiple forms of negation, an understanding of open domains and the closed world assumption, default reasoning with exceptions, reasoning with respect to time (i.e. a solution to the frame problem, and introspection with regard to previous beliefs), reasoning about actions, introspection, and maintaining multiple views of the world simultaneously.

The contribution of this paper is to discuss these developments in a singular, integrated, practical, digestible manner. Some of these ideas exist in a variety of papers spread across decades. They also exist in the minds of a very small community of researchers. Some of these ideas are unpublished. The presentation in this paper is from a different point of view, and intended to be more comprehensive and pedagogical. The presentation is also intended to be accessible to a much wider audience. Both the synthesis and the simplicity of this presentation are absent from the literature.
Microbiological quality of ice creams commercialized in some cities in the state of Rio de Janeiro, Brazil
Authors: DE FARIAS FABRÍCIO F , DA SILVA WALACE R , BOTELHO ANA CAROLINA N , DA HORA IRACEMA M DE C , KRONENBERGER GIOVAN , DA CRUZ ADRIANO G
Published: October 2006

The microbiological quality of 60 ice cream samples of three commercial brands (A, B and C) of various flavours, commercialized in some towns in the State of Rio de Janeiro, Brazil, was evaluated. Total bacteria count (TCB), coliforms at 35°C (CT), coliforms at 44°C (CF) and presence of Staphylococcus aureus were performed on all samples. TCB ranged from 2.0 × 102to 6.9 × 105 cfu/mL, CT from < 3–≥ 2400 MPN/mL, CF from < 3–1100 MPN/mL and S. aureus from < 10–1.4 × 106 cfu/mL. The level of bacterial contamination found in this study reflects the unhygienic conditions prevalent in manufacturing and storage of ice creams. Actions are thus necessary by the Brazilian regulatory agencies to require the ice cream processing plants to adopt quality guarantee systems, such as good manufacturing practices and hazard analysis and critical control points system.
The 160-Kilobase Genome of the Bacterial Endosymbiont
Carsonella
Authors: Nakabachi Atsushi , Yamashita Atsushi , Toh Hidehiro , Ishikawa Hajime , Dunbar Helen E. , Moran Nancy A. , Hattori Masahira
Published: October 2006

Previous studies have suggested that the minimal cellular genome could be as small as 400 kilobases. Here, we report the complete genome sequence of the psyllid symbiont Carsonella ruddii, which consists of a circular chromosome of 159,662 base pairs, averaging 16.5% GC content. It is by far the smallest and most AT-rich bacterial genome yet characterized. The genome has a high coding density (97%) with many overlapping genes and reduced gene length. Genes for translation and amino acid biosynthesis are relatively well represented, but numerous genes considered essential for life are missing, suggesting that Carsonella may have achieved organelle-like status.
Putative
cis
-Acting Stem-Loops in the 5′ Untranslated Region of the Severe Acute Respiratory Syndrome Coronavirus Can Substitute for Their Mouse Hepatitis Virus Counterparts
Authors: Kang Hyojeung , Feng Min , Schroeder Megan E. , Giedroc David P. , Leibowitz Julian L.
Published: October 2006

Consensus covariation-based secondary structural models for the 5′ 140 nucleotides of the 5′ untranslated regions (5′UTRs) from mouse hepatitis virus (MHV) and severe acute respiratory syndrome coronavirus (SCoV) were developed and predicted three major helical stem-loop structures, designated stem-loop 1 (SL1), SL2, and SL4. The SCoV 5′UTR was predicted to contain a fourth stem-loop, named SL3, in which the leader transcriptional regulatory sequence (TRS) is folded into a hairpin loop. cDNAs corresponding to MHV/SCoV chimeric genomes were constructed by replacing the complete MHV 5′UTR with the corresponding SCoV sequence and by separately replacing MHV 5′UTR putative SL1, putative SL2, TRS, and putative SL4 with the corresponding SCoV sequences. Chimeric genomes were transcribed in vitro, and viruses were recovered after electroporation into permissive cells. Genomes in which the MHV 5′UTR SL1, SL2, and SL4 were individually replaced by their SCoV counterparts were viable. Chimeras containing the complete SCoV 5′UTR or the predicted SCoV SL3 were not viable. A chimera containing the SCoV 5′UTR in which the SCoV TRS was replaced with the MHV TRS was also not viable. The chimera containing the entire SCoV 5′UTR failed to direct the synthesis of any virus-specific RNA. Replacing the SCoV TRS with the MHV TRS in the MHV/5′UTR SCoV chimera permitted the synthesis of minus-sense genome-sized RNA but did not support the production of positive- or minus-sense subgenomic RNA7. A similar phenotype was obtained with the MHV/SCoV SL3 chimera. These results suggest a role for the TRS in the replication of minus-sense genomic RNA in addition to its known function in subgenomic RNA synthesis.
Macrophage Transcriptional Responses following In Vitro Infection with a Highly Virulent African Swine Fever Virus Isolate
Authors: Zhang Fuquan , Hopwood Paul , Abrams Charles C. , Downing Alison , Murray Frazer , Talbot Richard , Archibald Alan , Lowden Stewart , Dixon Linda K.
Published: October 2006

We used a porcine microarray containing 2,880 cDNAs to investigate the response of macrophages to infection by a virulent African swine fever virus (ASFV) isolate, Malawi LIL20/1. One hundred twenty-five targets were found to be significantly altered at either or both 4 h and 16 h postinfection compared with targets after mock infection. These targets were assigned into three groups according to their temporal expression profiles. Eighty-six targets showed increased expression levels at 4 h postinfection but returned to expression levels similar to those in mock-infected cells at 16 h postinfection. These encoded several proinflammatory cytokines and chemokines, surface proteins, and proteins involved in cell signaling and trafficking pathways. Thirty-four targets showed increased expression levels at 16 h postinfection compared to levels at 4 h postinfection and in mock-infected cells. One host gene showed increased expression levels at both 4 and 16 h postinfection compared to levels in mock-infected cells. The microarray results were validated for 12 selected genes by quantitative real-time PCR. Levels of protein expression and secretion were measured for two proinflammatory cytokines, interleukin 1β and tumor necrosis factor alpha, during a time course of infection with either the virulent Malawi LIL20/1 isolate or the OUR T88/3 nonpathogenic isolate. The results revealed differences between these two ASFV isolates in the amounts of these cytokines secreted from infected cells.
Regulation of Inducible Nitric Oxide Synthase Expression by Viral A238L-Mediated Inhibition of p65/RelA Acetylation and p300 Transactivation
Authors: Granja Aitor G. , Sabina Prado , Salas María L. , Fresno Manuel , Revilla Yolanda
Published: October 2006

Uncontrolled generation of nitric oxide (NO) by inducible nitric-oxide synthase (iNOS) can cause damage to host cells and inflammation, two undesirable events for virus spreading. African swine fever virus (ASFV) infection regulates iNOS-induced gene expression through the synthesis of the A238L virus protein. We here explored the role of A238L, an NF-κB and NFAT inhibitor, in the regulation of iNOS transcription in macrophages. NO production and iNOS mRNA and protein levels as well as iNOS promoter activity after lipopolysaccharide (LPS)-gamma interferon (IFN-γ) treatment were down-regulated both during ASFV infection and in Raw 264.7 cells stably expressing the viral protein. Overexpression of p300, but not of a histone acetyltransferase (HAT) defective mutant, reverted the A238L-mediated inhibition of both basal and LPS-IFN-γ-induced iNOS promoter activity. Following stimulation with LPS-IFN-γ, p65 and p300 interaction was abolished in Raw-A238L cells. Expression of A238L also inhibited p65/relA and p300 binding to the distal NF-κB sequence of the iNOS promoter together with p65 acetylation. Finally, A238L abrogated p300 transactivation mediated by a GAL4-p300 construction. These results provide evidence for an unique viral mechanism involved in transcriptional regulation of iNOS gene expression.
ORF3 Protein of Hepatitis E Virus Is Not Required for Replication, Virion Assembly, or Infection of Hepatoma Cells In Vitro
Authors: Emerson Suzanne U. , Nguyen Hanh , Torian Udana , Purcell Robert H.
Published: October 2006

A subclone of Huh-7 cells that could be relatively efficiently transfected and infected with hepatitis E virus was identified. Following transfection, infectious virus was produced but remained predominantly cell associated. Intracellular virus, recovered by lysis of transfected cells, infected naïve cells. This in vitro-produced virus appeared to be antigenically identical to virus isolated from clinical samples. Lysates from cells transfected with mutant viral genomes unable to synthesize ORF3 protein contained infectious virions that were similar in number, thermostability, and sedimentation characteristics to those in lysates transfected with wild-type viral genomes. Therefore, in contrast to its requirement in vivo, ORF3 protein is not required for infection of Huh-7 cells or production of infectious virus in vitro.
Rotavirus Anti-VP6 Secretory Immunoglobulin A Contributes to Protection via Intracellular Neutralization but Not via Immune Exclusion
Authors: Corthésy Blaise , Benureau Yann , Perrier Clémentine , Fourgeux Cynthia , Parez Nathalie , Greenberg Harry , Schwartz-Cornil Isabelle
Published: October 2006

Immunoglobulin A (IgA) monoclonal antibodies (MAbs) directed at the conserved inner core protein VP6 of rotavirus, such as the IgA7D9 MAb, provide protective immunity in adult and suckling mice when delivered systemically. While these antibodies do not have traditional in vitro neutralizing activity, they could mediate their antiviral activity either by interfering with the viral replication cycle along the IgA secretory pathway or by acting at mucosal surfaces as secretory IgA and excluding virus from target enterocytes. We sought to determine the critical step at which antirotaviral activity was initiated by the IgA7D9 MAb. The IgA7D9 MAb appeared to directly interact with purified triple-layer viral particles, as shown by immunoprecipitation and immunoblotting. However, protection was not conferred by passively feeding mice with the secretory IgA7D9 MAb. This indicates that the secretory IgA7D9 MAb does not confer protection by supplying immune exclusion activity in vivo. We next evaluated the capacity of polymeric IgA7D9 MAb to neutralize rotavirus intracellularly during transcytosis. We found that when polymeric IgA7D9 MAb was applied to the basolateral pole of polarized Caco-2 intestinal cells, it significantly reduced viral replication and prevented the loss of barrier function induced by apical exposure of the cell monolayer to rotavirus, supporting the conclusion that the antibody carries out its antiviral activity intracellularly. These findings identify a mechanism whereby the well-conserved immunodominant VP6 protein can function as a target for heterotypic antibodies and protective immunity.
Identification of APOBEC3DE as Another Antiretroviral Factor from the Human APOBEC Family
Authors: Dang Ying , Wang Xiaojun , Esselman Walter J. , Zheng Yong-Hui
Published: October 2006

A tandem arrayed gene cluster encoding seven cytidine deaminase genes is present on human chromosome 22. These are APOBEC3A, APOBEC3B, APOBEC3C, APOBEC3DE, APOBEC3F, APOBEC3G, and APOBEC3H. Three of them, APOBEC3G, APOBEC3F, and APOBEC3B, block replication of human immunodeficiency virus type 1 (HIV-1) and many other retroviruses. In addition, APOBEC3A and APOBEC3C block intracellular retrotransposons and simian immunodeficiency virus (SIV), respectively. In opposition to APOBEC genes, HIV-1 and SIV contain a virion infectivity factor (Vif) that targets APOBEC3F and APOBEC3G for polyubiquitylation and proteasomal degradation. Herein, we studied the antiretroviral activities of the human APOBEC3DE and APOBEC3H. We found that only APOBEC3DE had antiretroviral activity for HIV-1 or SIV and that Vif suppressed this antiviral activity. APOBEC3DE was encapsidated and capable of deaminating cytosines to uracils on viral minus-strand DNA, resulting in disruption of the viral life cycle. Other than GG-to-AG and AG-to-AA mutations, it had a novel target site specificity, resulting in introduction of GC-to-AC mutations on viral plus-strand DNA. Such mutations have been detected previously in HIV-1 clinical isolates. In addition, APOBEC3DE was expressed much more extensively than APOBEC3F in various human tissues and it formed heteromultimers with APOBEC3F or APOBEC3G in the cell. From these studies, we concluded that APOBEC3DE is a new contributor to the intracellular defense network, resulting in suppression of retroviral invasion.
Identifying Epitopes Responsible for Neutralizing Antibody and DC-SIGN Binding on the Spike Glycoprotein of the Severe Acute Respiratory Syndrome Coronavirus
Authors: Shih Yi-Ping , Chen Chia-Yen , Liu Shih-Jen , Chen Kuan-Hsuan , Lee Yuan-Ming , Chao Yu-Chan , Chen Yi-Ming Arthur
Published: October 2006

The severe acute respiratory syndrome-associated coronavirus (SARS-CoV) uses dendritic cell-specific ICAM-3 grabbing nonintegrin (DC-SIGN) to facilitate cell entry via cellular receptor-angiotensin-converting enzyme 2. For this project, we used recombinant baculoviruses expressing different lengths of SARS-CoV spike (S) protein in a capture assay to deduce the minimal DC-SIGN binding region. Our results identified the region location between amino acid (aa) residues 324 to 386 of the S protein. We then generated nine monoclonal antibodies (MAbs) against the S protein to map the DC-SIGN-binding domain using capture assays with pseudotyped viruses and observed that MAb SIa5 significantly blocked S protein-DC-SIGN interaction. An enhancement assay using the HKU39849 SARS-CoV strain and human immature dendritic cells confirmed our observation. Data from a pepscan analysis and M13 phage peptide display library system mapped the reactive MAb SIa5 epitope to aa residues 363 to 368 of the S protein. Results from a capture assay testing three pseudotyped viruses with mutated N-linked glycosylation sites of the S protein indicate that only two pseudotyped viruses (N330Q and N357Q, both of which lost glycosylation sites near the SIa5 epitope) had diminished DC-SIGN-binding capacity. We also noted that MAb SIb4 exerted a neutralizing effect against HKU39849; its reactive epitope was mapped to aa residues 435 to 439 of the S protein. We offer the data to facilitate the development of therapeutic agents and preventive vaccines against SARS-CoV infection.
Human Papillomavirus Genotype 31 Does Not Express Detectable MicroRNA Levels during Latent or Productive Virus Replication
Authors: Cai Xuezhong , Li Gu , Laimins Laimonis A. , Cullen Bryan R.
Published: October 2006

It has recently become clear that several pathogenic DNA viruses express virally encoded microRNAs in infected cells. In particular, numerous microRNAs have been identified in a range of human and animal herpesviruses, and individual microRNAs have also been identified in members of the polyoma- and adenovirus families. Although their functions remain largely unknown, it seems likely that these viral microRNAs play an important role in viral replication in vivo. Here we present an analysis of the microRNAs expressed in human cells during the latent and productive phases of the human papillomavirus genotype 31 (HPV31) replication cycle. Although over 500 cellular microRNAs were cloned and identified, not a single HPV31-specific microRNA was obtained. We therefore concluded that HPV31, and possibly human papillomaviruses in general, does not express viral microRNAs.
Proteomic Analysis of the Major Envelope and Nucleocapsid Proteins of White Spot Syndrome Virus
Authors: Xie Xixian , Xu Limei , Yang Feng
Published: October 2006

White spot syndrome virus (WSSV) virions were purified from the tissues of infected
Procambarus clarkii
(crayfish) isolates. Pure WSSV preparations were subjected to Triton X-100 treatment to separate into the envelope and nucleocapsid fractions, which were subsequently separated by 12% sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The major envelope and nucleocapsid proteins were identified by either matrix-assisted laser desorption ionization-time of flight mass spectrometry or defined antibody. A total of 30 structural proteins of WSSV were identified in this study; 22 of these were detected in the envelope fraction, 7 in the nucleocapsid fraction, and 1 in both the envelope and the nucleocapsid fractions. With the aid of specific antibodies, the localizations of eight proteins were further studied. The analysis of posttranslational modifications revealed that none of the WSSV structural proteins was glycosylated and that VP28 and VP19 were threonine phosphorylated. In addition, far-Western and coimmunoprecipitation experiments showed that VP28 interacted with both VP26 and VP24. In summary, the data obtained in this study should provide an important reference for future molecular studies of WSSV morphogenesis.
VOCCs and TREK-1 ion channel expression in human tenocytes
Authors: Magra Merzesh , Hughes Steven , El Haj Alicia J. , Maffulli Nicola
Published: October 2006

Mechanosensitive and voltage-gated ion channels are known to perform important roles in mechanotransduction in a number of connective tissues, including bone and muscle. It is hypothesized that voltage-gated and mechanosensitive ion channels also may play a key role in some or all initial responses of human tenocytes to mechanical stimulation. However, to date there has been no direct investigation of ion channel expression by human tenocytes. Human tenocytes were cultured from patellar tendon samples harvested from five patients undergoing routine total knee replacement surgery (mean age: 66 yr; range: 63–73 yr). RT-PCR, Western blotting, and whole cell electrophysiological studies were performed to investigate the expression of different classes of ion channels within tenocytes. Human tenocytes expressed mRNA and protein encoding voltage-operated calcium channel (VOCC) subunits (Ca α1A, Ca α1C, Ca α1D, Ca α2δ1) and the mechanosensitive tandem pore domain potassium channel (2PK+) TREK-1. They exhibit whole cell currents consistent with the functional expression of these channels. In addition, other ionic currents were detected within tenocytes consistent with the expression of a diverse array of other ion channels. VOCCs and TREK channels have been implicated in mechanotransduction signaling pathways in numerous connective tissue cell types. These mechanisms may be present in human tenocytes. In addition, human tenocytes may express other channel currents. Ion channels may represent potential targets for the pharmacological management of chronic tendinopathies.
Circulating levels of cytochromecafter resuscitation from cardiac arrest: a marker of mitochondrial injury and predictor of survival
Authors: Radhakrishnan Jeejabai , Wang Sufen , Ayoub Iyad M. , Kolarova Julieta D. , Levine Rita F. , Gazmuri Raúl J.
Published: October 2006

Ca2+overload and reactive oxygen species can injure mitochondria during ischemia and reperfusion. We hypothesized that mitochondrial injury occurs during cardiac resuscitation, causing release of cytochrome c to the cytosol and bloodstream while activating apoptotic pathways. Plasma cytochrome c was measured using reverse-phase HPLC and Western immunoblotting in rats subjected to 4 or 8 min of untreated ventricular fibrillation and 8 min of closed-chest resuscitation followed by 240 min of postresuscitation hemodynamic observation. A sham group served as control. Plasma cytochrome c rose progressively to levels 10-fold higher than in sham rats 240 min after resuscitation ( P < 0.01), despite reversal of whole body ischemia (decreases in arterial lactate). Cytochrome c levels were inversely correlated with left ventricular stroke work ( r = −0.40, P = 0.02). Western immunoblotting of left ventricular tissue demonstrated increased levels of 17-kDa cleaved caspase-3 fragments in the cytosol. Plasma cytochrome c was then serially measured in 12 resuscitated rats until the rat died or cytochrome c returned to baseline. In three survivors, cytochrome c rose slightly to ≤2 μg/ml and returned to baseline within 96 h. In nine nonsurvivors, cytochrome c rose progressively to significantly higher maximal levels [4.6 (SD 2.0) vs. 1.6 (SD 0.3) μg/ml, P = 0.029] and at faster rates [0.7 (SD 0.5) vs. 0.1 (SD 0.1) μg·ml−1·h−1, P = 0.046] than in survivors. Plasma cytochrome c may represent a novel in vivo marker of mitochondrial injury after resuscitation from cardiac arrest that relates inversely with survival outcome.
Adenoviral expression of 15-lipoxygenase-1 in rabbit aortic endothelium: role in arachidonic acid-induced relaxation
Authors: Aggarwal Nitin T. , Holmes Blythe B. , Cui Lijie , Viita Helena , Yla-Herttuala Seppo , Campbell William B.
Published: October 2006

Endothelium-dependent vasorelaxation of the rabbit aorta is mediated by either nitric oxide (NO) or arachidonic acid (AA) metabolites from cyclooxygenase (COX) and 15-lipoxygenase (15-LO) pathways. 15-LO-1 metabolites of AA, 11,12,15-trihydroxyeicosatrienoic acid (THETA), and 15-hydroxy-11,12-epoxyeicosatrienoic acid (HEETA) cause concentration-dependent relaxation. We tested the hypothesis that in the 15-LO pathway of AA metabolism, 15-LO-1 is sufficient and is the rate-limiting step in inducing relaxations in rabbit aorta. Aorta and rabbit aortic endothelial cells were treated with adenoviruses containing human 15-LO-1 cDNA (Ad-15-LO-1) or β-galactosidase (Ad-β-Gal). Ad-15-LO-1-transduction increased the expression of a 75-kDa protein corresponding to 15-LO-1, detected by immunoblotting with an anti-human15-LO-1 antibody, and increased the production of HEETA and THETA from [14C]AA. Immunohistochemical studies on Ad-15-LO-1-transduced rabbit aorta showed the presence of 15-LO-1 in endothelial cells. Ad-15-LO-1-treated aortic rings showed enhanced relaxation to AA (max 31.7 ± 3.2%) compared with Ad-β-Gal-treated (max 12.7 ± 3.2%) or control nontreated rings (max 13.1 ± 1.6%) ( P < 0.01). The relaxations in Ad-15-LO-1-treated aorta were blocked by the 15-LO inhibitor cinnamyl-3,4-dihydroxy-a-cyanocinnamate. Overexpression of 15-LO-1 in the rabbit aortic endothelium is sufficient to increase the production of the vasodilatory HEETA and THETA and enhance the relaxations to AA. This confirms the role of HEETA and THETA as endothelium-derived relaxing factors.
Peroxynitrite diminishes myogenic tone in cerebral arteries: role of nitrotyrosine and F-actin
Authors: Maneen Matthew J. , Cipolla Marilyn J.
Published: October 2006

This study investigated the effect of peroxynitrite (OONO−)-induced nitrosylation of filamentous (F)-actin on myogenic tone in isolated and pressurized posterior cerebral arteries (PCAs). Immunohistochemical staining was used to determine 3-nitrotyrosine (NT) and F-actin content in vascular smooth muscle after exposure to 10−7 M or 10−4 M OONO− for 5 or 60 min in isolated third-order PCAs ( n = 37) from male Wistar rats pressurized to 75 mmHg in an arteriograph chamber, quantified with confocal microscopy. Additionally, the role of K+ channels in OONO−-induced dilation was investigated with 3 μM glibenclamide or 10 mM tetraethylammonium chloride before OONO− exposure. OONO− (10−4 M) induced a 40% dilation of tone ( P < 0.05) while diminishing F-actin content by half ( P < 0.05) and causing a 60-fold increase in NT ( P < 0.05) in the vascular smooth muscle of PCAs. Additionally, F-actin was inversely correlated with both diameter and NT content ( P < 0.05) and was significantly colocalized in the vascular smooth muscle with NT (overlap coefficient = 0.8). The dilation to ONOO− was independent of K+ channel activity and thiol oxidation as glibenclamide, tetraethylammonium chloride, and dithiothreitol had no effect on OONO−-induced dilation or F-actin or NT content in PCAs. Because NT was colocalized with F-actin, we hypothesize that OONO− induces nitrosylation of F-actin in vascular smooth muscle leading to depolymerization and the subsequent loss of myogenic tone, which may promote vascular damage during oxidative stress such as in ischemia and reperfusion injury.
Kv1.5 is a major component underlying the A-type potassium current in retinal arteriolar smooth muscle
Authors: McGahon Mary K. , Dawicki Jennine M. , Arora Aruna , Simpson D. A. , Gardiner T. A. , Stitt A. W. , Scholfield C. Norman , McGeown J. Graham , Curtis Tim M.
Published: October 2006

Little is known about the molecular characteristics of the voltage-activated K+(Kv) channels that underlie the A-type K+current in vascular smooth muscle cells of the systemic circulation. We investigated the molecular identity of the A-type K+current in retinal arteriolar myocytes using patch-clamp techniques, RT-PCR, immunohistochemistry, and neutralizing antibody studies. The A-type K+current was resistant to the actions of specific inhibitors for Kv3 and Kv4 channels but was blocked by the Kv1 antagonist correolide. No effects were observed with pharmacological agents against Kv1.1/2/3/6 and 7 channels, but the current was partially blocked by riluzole, a Kv1.4 and Kv1.5 inhibitor. The current was not altered by the removal of extracellular K+but was abolished by flecainide, indicative of Kv1.5 rather than Kv1.4 channels. Transcripts encoding Kv1.5 and not Kv1.4 were identified in freshly isolated retinal arterioles. Immunofluorescence labeling confirmed a lack of Kv1.4 expression and revealed Kv1.5 to be localized to the plasma membrane of the arteriolar smooth muscle cells. Anti-Kv1.5 antibody applied intracellularly inhibited the A-type K+current, whereas anti-Kv1.4 antibody had no effect. Co-expression of Kv1.5 with Kvβ1 or Kvβ3 accessory subunits is known to transform Kv1.5 currents from delayed rectifers into A-type currents. Kvβ1 mRNA expression was detected in retinal arterioles, but Kvβ3 was not observed. Kvβ1 immunofluorescence was detected on the plasma membrane of retinal arteriolar myocytes. The findings of this study suggest that Kv1.5, most likely co-assembled with Kvβ1 subunits, comprises a major component underlying the A-type K+current in retinal arteriolar smooth muscle cells.
Complementary Postsynaptic Activity Patterns Elicited in Olfactory Bulb by Stimulation of Mitral/Tufted and Centrifugal Fiber Inputs to Granule Cells
Authors: Laaris Nora , Puche Adam , Ennis Matthew
Published: October 2006

Main olfactory bulb (MOB) granule cells receive spatially segregated glutamatergic synaptic inputs from the dendrites of mitral/tufted cells as well as from the axons of centrifugal fibers (CFFs) originating in olfactory cortical areas. Dendrodendritic synapses from mitral/tufted cells occur on granule cell distal dendrites in the external plexiform layer (EPL), whereas CFFs preferentially target the somata/proximal dendrites of granule cells in the granule cell layer (GCL). In the present study, tract tracing, and recordings of field potentials and voltage-sensitive dye optical signals were used to map activity patterns elicited by activation of these two inputs to granule cells in mouse olfactory bulb slices. Stimulation of the lateral olfactory tract (LOT) produced a negative field potential in the EPL and a positivity in the GCL. CFF stimulation produced field potentials of opposite polarity in the EPL and GCL to those elicited by LOT. LOT-evoked optical signals appeared in the EPL and spread subsequently to deeper layers, whereas CFF-evoked responses appeared in the GCL and then spread superficially. Evoked responses were reduced by N-methyl-d-aspartate (NMDA) receptor antagonists and completely suppressed by AMPA receptor antagonists. Reduction of extracellular Mg2+enhanced the strength and spatiotemporal extent of the evoked responses. These and additional findings indicate that LOT- and CFF-evoked field potentials and optical signals reflect postsynaptic activity in granule cells, with moderate NMDA and dominant AMPA receptor components. Taken together, these results demonstrate that LOT and CFF stimulation in MOB slices selectively activate glutamatergic inputs to the distal dendrites versus somata/proximal dendrites of granule cells.
Hepatitis C Virus Core Protein: An Update on Its Molecular Biology, Cellular Functions and Clinical Implications
Authors: Irshad M. , Dhar Indranil
Published: October 2006

The present review article is an update on various features of hepatitis C virus (HCV) core protein including its molecular biology, role in HCV replication, involvement in HCV pathogenesis, etiological role in hepatocellular carcinogenesis, significance in diagnosis and vaccination against HCV infection. Core protein is a structural protein of HCV virus and has only recently been characterized. It was found to play a major role in HCV-induced viral hepatitis. Although published information shows a lot about the clinical significance of HCV core protein, several studies are still needed to demonstrate its exact significance in viral biology and underlying HCV pathogenesis.
Pre-Operative Endovascular Embolization of a Cerebellar Haemangioblastoma
Authors: Abo-Al Hassan A. , Ismail M. , Panda S.M.
Published: October 2006

Objective: To present an interesting case of pre-operative embolization of a cerebellar haemangioblastoma. Clinical Presentation and Intervention: A 36-year-old male presented with gradual, progressive headache and a positive family history of von Hippel-Lindau syndrome. MRI of the brain revealed a right cerebellar solid mass and cerebral angiography demonstrated its extensive hypervascular nature. The mass was embolized with polyvinyl alcohol prior to surgical resection, which resulted in improvement of the patient’s symptoms. Conclusion: Pre-operative embolization of a haemangioblastoma is a useful procedure that can potentially decrease the morbidity and mortality of its surgical resection.
Tutorial in Biostatistics: Analyzing Associations between Total Plasma Homocysteine and B Vitamins Using Optimal Categorization and Segmented Regression
Authors: Bang Heejung , Mazumdar Madhu , Spence David
Published: October 2006

Data analysts consider standard regression models (e.g., generalized linear model) or nonparametric smoothing techniques (e.g., loess or splines) when examining the association between two variables. Before this step, a quantile-based summarization is typically used for exploring the exposure-response relationship. Unfortunately, these exploratory approaches may not be optimal or efficient for guiding the formal analysis in many biological and nutritional data settings. We suggest a recently developed method for selection of cutpoints as a tool of data summary and segmented regression as a modeling approach in the analysis of plasma total homocysteine and related vitamins. These methods are often complementary in discovering the underlying complex pattern of association.
In Search for New Antipsoriatic Agents: NAD+ Topical Composition
Authors: Wozniacka A. , Szajerski P. , Adamus J. , Gebicki J. , Sysa-Jedrzejowska A.
Published: October 2006

The aim of the study was to examine the effectiveness of the oxidized form of nicotinamide adenine dinucleotide (NAD+), adenosine precursor, in 37 patients suffering from psoriasis. As NAD+ is known to be relatively unstable, the second goal was to establish the proper conditions for the satisfactory stability of topical NAD+ composition. In each patient, two matching plaques were selected for the study. Topical treatment with 1 or 0.3% NAD+ in Vaseline ointment administered twice daily was compared with overnight therapy with 0.1% anthralin applied for 12 h and placebo. The enzymatic method was applied to determine the stability of NAD+ in Vaseline ointment. After a 4-week application, the reduction in erythema, infiltration and desquamation caused by 1 or 0.3% topical NAD+ composition was similar to the reduction caused by 0.1% anthralin. It was demonstrated that NAD+ underwent a considerable decomposition at room temperature, while it was sufficiently stable at 5°C; thus, for a longer use the agent should be stored at fridge temperature. NAD+ therapy combines good efficacy, cosmetic acceptability and convenient twice-daily application.
Influence of Applied Quantity of Sunscreen Products on the Sun Protection Factor – A Multicenter Study Organized by the DGK Task Force Sun Protection
Authors: Bimczok R. , Gers-Barlag H. , Mundt C. , Klette E. , Bielfeldt S. , Rudolph T. , Pflücker F. , Heinrich U. , Tronnier H. , Johncock W. , Klebon B. , Westenfelder H. , Flöβer-Müller H. , Jenni K. , Kockott D. , Lademann J. , Herzog B. , Rohr M.
Published: October 2006

It is often debated that the protection against solar-induced erythema under real conditions is dependent upon the amount of sunscreen applied. It is believed that when too little is applied a lower sun protection than indicated on the label will result. The aim of this study was to quantify this effect. In this multicenter study, the influence of three different amounts (0.5, 1.0, 2.0 mg/cm2) of three commercial sunscreen products in three reliable test centers was investigated according to the test protocol of The International Sun Protection Factor Test Method. The main result was a linear dependence of the SPF on the quantity applied. Taking into consideration the volunteer-specific variations, an exponential dependence of confidence interval of the in vivo SPF and amount applied was found. The highest amount applied (2.0 mg/cm2) was linked to the lowest confidence intervals. Thus, from the point of view of producing reliable and reproducible in vivo results under laboratory conditions, the recommendation of this multicenter study is an application quantity of 2.0 mg/cm2.
Relieving Isolation, Avoiding Vices: The Social Purposes of Participation in A Salvadoran Literacy Program
Authors: Prins Esther
Published: October 2006

This article uses ethnographic research to examine how women and men in rural El Salvador used literacy classes to accomplish their own social purposes. Employing a sociocultural, feminist framework, the author argues that men and women valued classes as an opportunity for social interaction. Moreover, the classes were a gendered social space that helped women to relieve isolation and men to spend their time purposefully and “avoid vices” like drinking. These needs were rooted in gender relations (an inequitable gender division of labor, the restriction of female mobility, the sanctioning of drinking as masculine behavior) and socioeconomic conditions (unemployment, postwar social fragmentation). Attending classes allowed learners to construct identities that challenged dominant conceptions of gender. The article proposes that serving the human longing for affiliation is a legitimate, essential role of adult education. It concludes by suggesting ways to analyze and support social interaction in adult and literacy education.
Bridging the Divide
Authors: Grose Christian R.
Published: October 2006

Are minority press outlets more likely to provide coverage of minority legislators than white legislators? Does this coverage translate across racial and ethnic lines? This article assesses whether minority members of the 107th Congress (2001–02) are covered by minority media sources more than white legislators. The author examines the frequency of media coverage of Latino,African-American, and Asian-American legislators in the Latino press, the African-American press, and the Asian-American press.The author argues and finds that minority elected officials are more likely to receive coverage in newspapers geared specifically to minority communities. Minority legislators are more likely to be covered by minority media, and these results are robust across minority media.The author also finds that minority media are more likely to give coverage to legislators from other minority groups as well. African-American and Latino legislators receive more coverage from Latino media outlets than other legislators,while the same results are found for African-American media outlets. Asian-American media outlets are more likely to cover both Asian-American and African-American legislators.
Minority Candidates, Media Framing, and Racial Cues in the 2004 Election
Authors: Caliendo Stephen M. , McIlwain Charlton D.
Published: October 2006

Rooted in political communication models of framing and priming and a rather unique theory of appeals to racial authenticity, the authors examine minority candidates in both majority-minority and majority-white districts during the 2004 election cycle.They explore and analyze potential framing and priming effects based on variations of candidates’ media coverage in a number of campaign scenarios. Results suggest that racial references are commonplace in biracial election contests (and are more likely to occur there than in all-white contests). Furthermore, newspaper coverage of biracial and all-black elections is more likely to contain a racial frame than stories about all-white races. The authors conclude with a discussion of the normative implications of these findings, as well as suggestions for further examination and testing.
Comparative Cultural Salience: Measures Using Free-List Data
Authors: Thompson Eric C. , Juan Zhang
Published: October 2006

In this article, we discuss procedures for comparing the cultural salience of semantic domains and their constitutive signifiers between groups of respondents based on free list data. These methods allow us to assess the relative similarity and difference of the cognitive salience of elements within a domain across groups of respondents. We argue that cultural salience is an important but often overlooked variable in the structure of semantic domains. Comparing cultural salience provides one grounds for claims of cultural difference (or lack thereof) between different socially defined groups (e.g., national, ethnic, gender, academic). We use data collected on the cultural salience of countries in a project on perceptions of Southeast Asia as an example of the methods described.
Integrative missing value estimation for microarray data
Authors: Hu Jianjun , Li Haifeng , Waterman Michael S , Zhou Xianghong Jasmine
Published: October 2006

Background

Missing value estimation is an important preprocessing step in microarray analysis. Although several methods have been developed to solve this problem, their performance is unsatisfactory for datasets with high rates of missing data, high measurement noise, or limited numbers of samples. In fact, more than 80% of the time-series datasets in Stanford Microarray Database contain less than eight samples.

Results

We present the integrative Missing Value Estimation method (iMISS) by incorporating information from multiple reference microarray datasets to improve missing value estimation. For each gene with missing data, we derive a consistent neighbor-gene list by taking reference data sets into consideration. To determine whether the given reference data sets are sufficiently informative for integration, we use a submatrix imputation approach. Our experiments showed that iMISS can significantly and consistently improve the accuracy of the state-of-the-art Local Least Square (LLS) imputation algorithm by up to 15% improvement in our benchmark tests.

Conclusion

We demonstrated that the order-statistics-based integrative imputation algorithms can achieve significant improvements over the state-of-the-art missing value estimation approaches such as LLS and is especially good for imputing microarray datasets with a limited number of samples, high rates of missing data, or very noisy measurements. With the rapid accumulation of microarray datasets, the performance of our approach can be further improved by incorporating larger and more appropriate reference datasets.
Genepi: a blackboard framework for genome annotation
Authors: Descorps-Declère Stéphane , Ziébelin Danielle , Rechenmann François , Viari Alain
Published: October 2006

Background

Genome annotation can be viewed as an incremental, cooperative, data-driven, knowledge-based process that involves multiple methods to predict gene locations and structures. This process might have to be executed more than once and might be subjected to several revisions as the biological (new data) or methodological (new methods) knowledge evolves. In this context, although a lot of annotation platforms already exist, there is still a strong need for computer systems which take in charge, not only the primary annotation, but also the update and advance of the associated knowledge. In this paper, we propose to adopt a blackboard architecture for designing such a system

Results

We have implemented a blackboard framework (called Genepi) for developing automatic annotation systems. The system is not bound to any specific annotation strategy. Instead, the user will specify a blackboard structure in a configuration file and the system will instantiate and run this particular annotation strategy. The characteristics of this framework are presented and discussed. Specific adaptations to the classical blackboard architecture have been required, such as the description of the activation patterns of the knowledge sources by using an extended set of Allen's temporal relations. Although the system is robust enough to be used on real-size applications, it is of primary use to bioinformatics researchers who want to experiment with blackboard architectures.

Conclusion

In the context of genome annotation, blackboards have several interesting features related to the way methodological and biological knowledge can be updated. They can readily handle the cooperative (several methods are implied) and opportunistic (the flow of execution depends on the state of our knowledge) aspects of the annotation process.
Methotrexate-induced renal oxidative stress in rats: the role of a novel antioxidant caffeic acid phenethyl ester
Authors: Öktem Faruk , Yilmaz H Ramazan , Ozguner Fehmi , Olgar Seref , Ayata Ali , Uzar Ertugrul , Uz Efkan
Published: October 2006

The exact mechanisms of methotrexate-induced renal toxicity have not yet been determined. However, several hypotheses have been put forward, including oxidative stress. The aim of this study was to investigate the role of caffeic acid phenethyl ester (Caffeic Ester), a novel antioxidant, on methotrexate-induced renal oxidative stress in rats. Nineteen adult male rats were equally divided into three experimental groups as follows: control group, methotrexate-treated group, and methotrexate-/Caffeic Ester-treated group. A single dose of methotrexate (20 mg/kg) was administered intraperitoneally (ip). Caffeic Ester (10 mmol/kg) was administered ip, once daily for seven days. Malondialdehyde (MDA) levels (an index of lipid peroxidation) were used as a marker of oxidative stress-induced renal injury. Similarly, the activities of superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) were determined to evaluate the changes of antioxidant status in renal tissue. Methotrexate administration to control rats increased MDA levels (PB < 0.0001), but decreased SOD, CAT and GSH-Px activities in renal tissue (PB < 0.0001). Caffeic Ester-/methotrexate treatment caused a significant decrease in MDA levels (PB < 0.001), and caused an increase in SOD, CAT and GSH-Px activities when compared with methotrexate treatment alone (PB < 0.001, < 0.05, < 0.0001, respectively). In conclusion, methotrexate leads to a reduction in antioxidant enzymatic defense capacity and causes lipid peroxidation in renal tissue. Similarly, Caffeic Ester exhibits protective effects on methotrexate-induced renal oxidative impairment in rats.
Development of a rat pilocarpine model of seizure/status epilepticus that mimics chemical warfare nerve agent exposure
Authors: Tetz Lauren M , Rezk Peter E , Ratcliffe Ruthie H , Gordon Richard K , Steele Keith E , Nambiar Madhusoodana P
Published: October 2006

We developed a rat pilocarpine seizure/status epilepticus (SE) model, which closely resembles 1.6-2.0/LD50 soman exposure, to analyse the molecular mechanism of neuronal damage and to screen effective neuroprotectants against cholinergic agonist and chemical warfare nerve agent (CWNA) exposure. Rats implanted with radiotelemetry probes capable of recording electroencephalogram (EEG), electrocardiogram (ECG), temperature, and physical activity were treated with lithium chloride (5 mEq/kg, im), followed 24 h later by (ip) doses of pilocarpine hydrochloride. Based on radiotelemetry analysis, a dose of 240 mg/kg (ip) pilocarpine generated seizure/SE analogous to 1.6-2.0/LD50 of soman. The model was refined by reducing the peripheral convulsions without affecting the central nervous system (CNS) by administering methylscopolamine bromide (1 mg/kg, ip), an anti-cholinergic that does not cross the blood brain barrier. However, when methylscopolamine bromide was administered, a higher dose of pilocarpine (320 mg/kg, ip) was required to generate the equivalent seizure/SE. Histopathology data indicated that pilocarpine induces significant damage to the hippocampal region of the brain, with similar neuropathology to that of 1.6-2.0/LD50 soman exposure. There was a reduction in body temperature after the administration of pilocarpine, as observed in organophosphate (OP) nerve agents exposure. The heart-rate of pilocarpine-treated animals increased compared to the normal range. The pilocarpine seizure/SE model was also reproducible in the absence of lithium chloride. These results support that pilocarpine seizure/SE model is useful in studying the molecular mechanisms of neuropathology and screening neuroprotectants following cholinergic agonist and CWNA exposure.