bluuebunny/crossref_metadata_2025_split huggingface dataset:
pH-Induced Activation of Arenavirus Membrane Fusion Is Antagonized by Small-Molecule Inhibitors
Authors: York Joanne , Dai Dongcheng , Amberg Sean M. , Nunberg Jack H. 
Published: September 2008

ABSTRACT
The arenavirus envelope glycoprotein (GPC) mediates viral entry through pH-induced membrane fusion in the endosome. This crucial process in the viral life cycle can be specifically inhibited in the New World arenaviruses by the small-molecule compound ST-294. Here, we show that ST-294 interferes with GPC-mediated membrane fusion by targeting the interaction of the G2 fusion subunit with the stable signal peptide (SSP). We demonstrate that amino acid substitutions at lysine-33 of the Junín virus SSP confer resistance to ST-294 and engender de novo sensitivity to ST-161, a chemically distinct inhibitor of the Old World Lassa fever virus. These compounds, as well as a broadly active inhibitor, ST-193, likely share a molecular target at the SSP-G2 interface. We also show that both ST-294 and ST-193 inhibit pH-induced dissociation of the G1 receptor-binding subunit from GPC, a process concomitant with fusion activation. Interestingly, the inhibitory activity of these molecules can in some cases be overcome by further lowering the pH used for activation. Our results suggest that these small molecules act to stabilize the prefusion GPC complex against acidic pH. The pH-sensitive interaction between SSP and G2 in GPC represents a robust molecular target for the development of antiviral compounds for the treatment of arenavirus hemorrhagic fevers.
Antiretroviral Therapy prior to Acute Viral Replication Preserves CD4 T Cells in the Periphery but Not in Rectal Mucosa during Acute Simian Immunodeficiency Virus Infection
Authors: Kader Muhamuda , Hassan Wail M. , Eberly Matthew , Piatak Michael , Lifson Jeffrey D. , Roederer Mario , Mattapallil Joseph J. 
Published: September 2008

ABSTRACT
The rectal mucosa is a major site for human immunodeficiency virus entry and CD4 T-cell depletion. The early and near-total loss of these cells from the rectal mucosa severely compromises the ability of the mucosal immune system to control various opportunistic infections. Protecting these cells from infection and destruction can delay disease progression, leading to a better long-term outcome. Here we show that effective suppression of viral infection in memory CD4 T cells from the rectal mucosa and peripheral blood to a very low level with antiretroviral therapy (ART) initiated prior to the peak of infection is associated with opposite outcomes in these tissues. A near-total loss of CD4 T cells in the rectal mucosa contrasted with preservation of most memory CD4 T cells in peripheral blood during the course of treatment. Interestingly, ART significantly reduced viral infection in memory CD4 T cells from both rectal mucosa and peripheral blood. Although early ART was of limited value in protecting the CD4 T cells in the rectal mucosa, the significant preservation of peripheral CD4 T cells could contribute to maintaining immune competence, leading to a better long-term outcome.
Influenza B Virus NS1-Truncated Mutants: Live-Attenuated Vaccine Approach
Authors: Hai Rong , Martínez-Sobrido Luis , Fraser Kathryn A. , Ayllon Juan , García-Sastre Adolfo , Palese Peter 
Published: September 2008

ABSTRACT

Type B influenza viruses can cause substantial morbidity and mortality in the population, and vaccination remains by far the best means of protection against infections with these viruses. Here, we report the construction of mutant influenza B viruses for potential use as improved live-virus vaccine candidates. Employing reverse genetics, we altered the NS1 gene, which encodes a type I interferon (IFN) antagonist. The resulting NS1 mutant viruses induced IFN and, as a consequence, were found to be attenuated in vitro and in vivo. The absence of pathogenicity of the NS1 mutants in both BALB/c and C57BL/6 PKR
−/−
mice was confirmed. We also provide evidence that influenza B virus NS1 mutants induce a self-adjuvanted immune response and confer effective protection against challenge with both homologous and heterologous B virus strains in mice.
Hepatitis C Virus Core Protein Augments Androgen Receptor-Mediated Signaling
Authors: Kanda Tatsuo , Steele Robert , Ray Ranjit , Ray Ratna B. 
Published: September 2008

ABSTRACT
Hepatitis C virus (HCV) infection is frequently associated with the development of hepatocellular carcinoma (HCC), which is one of the male-dominant diseases. Androgen signaling in liver may be related to carcinogenesis. In this study, we investigated whether HCV proteins cross talk with the androgen receptor (AR) signaling pathway for promotion of carcinogenesis. We have demonstrated that HCV core protein alone or in context with other HCV proteins enhances AR-mediated transcriptional activity and further augments in the presence of androgen. Subsequent study suggested that HCV core protein activates STAT3, which in turn enhances AR-mediated transcription. This activity was blocked by a pharmacological inhibitor of the Jak/Stat signaling pathway, AG490. Vascular endothelial growth factor (VEGF) is a target gene of AR in liver and plays an important role in angiogenesis. Therefore, we examined whether HCV infection modulates VEGF expression in hepatocytes. Our results demonstrated that HCV enhances VEGF expression and facilitates tube formation in human coronary microvascular endothelial cells in the presence of AR. Together, our results suggest that HCV core protein acts as a positive regulator in AR signaling, providing further insight into oncogenic potential in the development of HCC in HCV-infected individuals.
Efficient Subgroup C Avian Sarcoma and Leukosis Virus Receptor Activity Requires the IgV Domain of the Tvc Receptor and Proper Display on the Cell Membrane
Authors: Munguia Audelia , Federspiel Mark J. 
Published: September 2008

ABSTRACT
We recently identified and cloned the receptor for subgroup C avian sarcoma and leukosis viruses [ASLV(C)], i.e., Tvc, a protein most closely related to mammalian butyrophilins, which are members of the immunoglobulin protein family. The extracellular domain of Tvc contains two immunoglobulin-like domains, IgV and IgC, which presumably each contain a disulfide bond important for native function of the protein. In this study, we have begun to identify the functional determinants of Tvc responsible for ASLV(C) receptor activity. We found that the IgV domain of the Tvc receptor is responsible for interacting with the glycoprotein of ASLV(C). Additional experiments demonstrated that a domain was necessary as a spacer between the IgV domain and the membrane-spanning domain for efficient Tvc receptor activity, most likely to orient the IgV domain a proper distance from the cell membrane. The effects on ASLV(C) glycoprotein binding and infection efficiency were also studied by site-directed mutagenesis of the cysteine residues of Tvc as well as conserved amino acid residues of the IgV Tvc domain compared to other IgV domains. In this initial analysis of Tvc determinants important for interacting with ASLV(C) glycoproteins, at least two aromatic amino acid residues in the IgV domain of Tvc, Trp-48 and Tyr-105, were identified as critical for efficient ASLV(C) infection. Interestingly, one or more aromatic amino acid residues have been identified as critical determinants in the other ASLV(A-E) receptors for a proper interaction with ASLV glycoproteins. This suggests that the ASLV glycoproteins may share a common mechanism of receptor interaction with an aromatic residue(s) on the receptor critical for triggering conformational changes in SU that initiate the fusion process required for efficient virus infection.
Molecular and Transmission Characteristics of Primary-Passaged Ovine Scrapie Isolates in Conventional and Ovine PrP Transgenic Mice
Authors: Thackray Alana M. , Hopkins Lee , Spiropoulos John , Bujdoso Raymond 
Published: September 2008

ABSTRACT

A more complete assessment of ovine prion strain diversity will be achieved by complementing biological strain typing in conventional and ovine PrP transgenic mice with a biochemical analysis of the resultant PrPSc. This will provide a correlation between ovine prion strain phenotype and the molecular nature of different PrP conformers associated with particular prion strains. Here, we have compared the molecular and transmission characteristics of ovine ARQ/ARQ and VRQ/VRQ scrapie isolates following primary passage in
tg338
(VRQ) and
tg59
(ARQ) ovine PrP transgenic mice and the conventional mouse lines C57BL/6 (
Prnp

a

), RIII (
Prnp

a

), and VM (
Prnp

b

). Our data show that these different genotypes of scrapie isolates display similar incubation periods of >350 days in conventional and
tg59
mice. Facilitated transmission of sheep scrapie isolates occurred in
tg338
mice, with incubation times reduced to 64 days for VRQ/VRQ inocula and to ≤210 days for ARQ/ARQ samples. Distinct genotype-specific lesion profiles were seen in the brains of conventional and
tg59
mice with prion disease, which was accompanied by the accumulation of more conformationally stable PrPSc, following inoculation with ARQ/ARQ compared to VRQ/VRQ scrapie isolates. In contrast, the lesion profiles, quantities, and stability of PrPSc induced by the same inocula in
tg338
mice were more similar than in the other mouse lines. Our data show that primary transmission of different genotypes of ovine prions is associated with the formation of different conformers of PrPSc with distinct molecular properties and provide the basis of a molecular approach to identify the true diversity of ovine prion strains.
Novel Characteristics of the Function and Induction of Murine p56 Family Proteins
Authors: Fensterl Volker , White Christine L. , Yamashita Michifumi , Sen Ganes C. 
Published: September 2008

ABSTRACTThe interferon-stimulated gene 56 (ISG56) family is induced strongly in response to virus infection, interferons (IFNs) and double-stranded RNA (dsRNA). In the mouse, this family comprises three members, ISG56, ISG54, and ISG49, which are clustered on chromosome 19 and encode the corresponding proteins p56, p54, and p49. Here, we report differential properties of these proteins and their distinct induction patterns in different cell types. All three murine proteins bound to the c-subunit of the translation initiation factor eIF3, but unlike the other members, p49 did not inhibit protein synthesis. Using a newly raised antibody, we demonstrated that both in vitro and in vivo, p49 expression was strongly induced by IFN, dsRNA, and Sendai virus. However, in kidney mesangial cells, as opposed to podocytes, encephalomyocarditis virus, vesicular stomatitis virus, or extracellular dsRNA did not induce any of the p56 family proteins, although they were robustly expressed after Sendai virus infection or dsRNA transfection. Furthermore, protein-specific differences in the regulation of p56 family members became evident in various leukocyte types: all three proteins were induced by IFN in T cells, but in B cells p56 and ISG56 mRNA could not be detected. Similarly, p56 was selectively uninducible in plasmacytoid dendritic cells, whereas in myeloid dendritic cells, all three family members were expressed. These results revealed novel cell type-, inducer-, and gene-specific regulation of the ISG56 family of genes.
Cross-Species Virus Transmission and the Emergence of New Epidemic Diseases
Authors: Parrish Colin R. , Holmes Edward C. , Morens David M. , Park Eun-Chung , Burke Donald S. , Calisher Charles H. , Laughlin Catherine A. , Saif Linda J. , Daszak Peter 
Published: September 2008

SUMMARYHost range is a viral property reflecting natural hosts that are infected either as part of a principal transmission cycle or, less commonly, as “spillover” infections into alternative hosts. Rarely, viruses gain the ability to spread efficiently within a new host that was not previously exposed or susceptible. These transfers involve either increased exposure or the acquisition of variations that allow them to overcome barriers to infection of the new hosts. In these cases, devastating outbreaks can result. Steps involved in transfers of viruses to new hosts include contact between the virus and the host, infection of an initial individual leading to amplification and an outbreak, and the generation within the original or new host of viral variants that have the ability to spread efficiently between individuals in populations of the new host. Here we review what is known about host switching leading to viral emergence from known examples, considering the evolutionary mechanisms, virus-host interactions, host range barriers to infection, and processes that allow efficient host-to-host transmission in the new host population.
An uncommon H3/Ser10 phosphorylation pattern inCestrum strigilatum(Solanaceae), a species with B chromosomes
Authors: Fernandes Thiago , Yuyama Priscila Mary , Moraes Ana Paula , Vanzela André Luís Laforga 
Published: September 2008

Cestrum strigilatum (Solanaceae) is a South American shrub with B chromosomes. Bs show a univalent behavior when a single B is present, have non-Mendelian segregation, and are poor in genes and rich in repetitive DNA. In this study, the histone H3 at serine 10 (H3/Ser10) phosphorylation pattern was investigated during mitosis and meiosis of C. strigilatum collected from the wild and was compared in A and B chromosomes. The results revealed that H3/Ser10 phosphorylation of A chromosomes occurred only in the pericentromeric region in both mitosis and meiosis, whereas in the B univalent, phosphorylation appeared in almost the whole extent of the chromosome, except in the terminal portion of the long arm. In meiosis II, the phosphorylation of A chromosomes was similar to that in the first division of meiosis, but the Bs did not show H3/Ser10 phosphorylation. Our results suggest that phosphorylation at the pericentromeric region may be associated with chromosome motility during cell divisions and with the cohesion of B chromatids in a univalent structure in meiosis I.
Genetic recombination in Sorghum bicolor × S. macrospermum interspecific hybrids
Authors: Kuhlman Les C. , Burson Byron L. , Klein Patricia E. , Klein Robert R. , Stelly David M. , Price H. James , Rooney William L. 
Published: September 2008

Sorghum has been improved by public and private breeding programs utilizing germplasm mostly from within the species Sorghum bicolor . Until recently, cross-incompatibilities have prevented hybridization of S. bicolor with most other species within the genus Sorghum . Utilizing germplasm homozygous for the iap allele, hybrids were readily produced between S. bicolor (2n = 20; AAB1B1) and S. macrospermum (2n = 40; WWXXYYZZ). These hybrids were intermediate to the parents in chromosome number (2n = 30) and overall morphology. Meiosis in both parents was regular; S. bicolor had 10 bivalents per pollen mother cell (PMC) and S. macrospermum had an average of 19.96 bivalents per PMC. Six hybrids were studied cytologically and meiosis was irregular, with the chromosomes associating primarily as univalents and bivalents. There was an average of 3.54 bivalents per PMC, with a range of 0–8 bivalents, most of which were rods (98%). Using FISH (fluorescent in situ hybridization), moderate levels (2.6 II per PMC) of allosyndetic recombination were observed. Genomic relationships were sufficient to assign S. macrospermum the genomic formula AAB1B1YYZZ (Y and Z remain unknown). Allosyndetic recombination in the interspecific hybrids indicates that introgression through genetic recombination should be possible if viable backcrosses can be recovered.
Development and testing of a low sludge discharge membrane bioreactor for greywater reclamation
Authors: Young Stephanie , Xu Aotian 
Published: September 2008

A low sludge discharge membrane bioreactor (LSDMBR) for greywater reclamation was developed and tested in this study. LSDMBR was designed by combining an aerobic activated sludge process with an immersed membrane filtration process. LSDMBR offers the following advantages over conventional activated sludge processes. Firstly, LSDMBR has a high biomass concentration attributed to membrane filtration of the effluent and low sludge wasting, which results in reduced disposal costs. Secondly, LSDMBR provides for a favorable environment for nitrifying bacteria and the promotion of their growth. Finally, LSDMBR provides for higher treatment efficiencies and produces higher-quality effluent for reuse over conventional processes. It was found from laboratory testing that the contaminant removal efficiencies achieved by LSDMBR within 2.5 h of hydraulic retention time (HRT) were as follows: 95% removal of anionic surfactants and 90% removal of 5-day biochemical oxygen demand (BOD5), respectively. It was also found that the effluent ammonia and total Kjeldahl nitrogen (TKN) concentrations were reduced to less than 1 mg/L and 6 mg/L, respectively. Results of the study suggested that LSDMBR is a small-scale and self-sustaining greywater reclamation system that requires low installation space and low sludge discharge.
Use of dairy sludge for the removal of some basic dyes
Authors: Sumanjit  , Walia Tejinder Pal Singh 
Published: September 2008

Dairy sludge, which is produced as a result of the activated sludge process, used in the dairy processing industries for treating their effluents, is a low cost, locally available and relatively new adsorbent. It is being investigated for its capacity to remove some of the basic dyes such as aniline blue, crystal violet, malachite green, methylene blue, rhodamine-B, and safranine from aqueous solutions. The effects of various experimental parameters;; initial pH, dye concentration, sorbent dosage, ion strength, and contact time, were examined and optimal experimental conditions were decided. At initial basic pH of 10, all six of the dyes studied could be removed effectively and in a very short period of time of just 35 min. The isothermal data for adsorption followed the Freundlich and Langmuir models. The adsorption results in this study indicated that all the dyes studied in this work can be easily removed by the application of dairy sludge.
Field-scale treatment of landfill gas with a passive methane oxidizing biofilter
Authors: Philopoulos Andrew , Felske Christian , McCartney Daryl 
Published: September 2008

Municipal solid waste landfills are a major contributor to global methane emissions, a potent greenhouse gas. A treatment alternative was evaluated by installing three biogenic methane oxidizing biofilters into the landfill cover at the Leduc and District Regional Landfill (Alberta). Mature yard-waste compost was used as the biofilter medium. The results, collected over a period of 10 months, showed that two sites performed well as low surface emissions (<15 g CH4 m–2 d–1) were observed on 6 of 8 monitoring events. These two sites also demonstrated sufficient temperature (>20 °C) and moisture (>0.25 L L–1) levels to support a high level of biogenic activity, the former despite cold winter temperatures (<0 °C). The third site showed low calculated methane influent flows (<5 g CH4 m–2 d–1) and therefore observations of performance were limited.
Investigation on the use of nitrified wastewater for the steady-state operation of a biotrickling filter for the removal of hydrogen sulphide in biogas
Authors: Soreanu Gabriela , Béland Michel , Falletta Patricia , Edmonson Kara , Seto Peter 
Published: September 2008

A biological process for the removal of hydrogen sulphide (H2S) in digester biogas was investigated using nitrified municipal wastewater as a nutrient solution under anoxic conditions. Biogas was continuously fed into a 0.012 m3 biotrickling filter at an H2S loading rate of approximately 1.50 g/d, counter-current to the nutrient solution. A zero-order macro-kinetic process was established on the basis of the degradation and formation rates for N and S species. The process performance was dependent on the presence of nitrate at low concentrations (in the order of 20 mg N-NO3–/L) found to be sufficient to maintain maximum H2S removal efficiency (>99%) under steady-state conditions where nitrate degradation rate was constant. The developed process has the potential to be adopted as an attractive alternative for biogas cleaning and, in some cases, with simultaneous wastewater denitrification. The information contained within this paper may be used as a basis for further research and (or) in the design of a scaled-up process.
Removal of Cr(VI) from wastewater using activated tamarind seeds as an adsorbent
Authors: Babu B.V. , Gupta Suresh 
Published: September 2008

In the present study, an adsorbent was prepared from tamarind seeds and batch studies were conducted for Cr(VI) removal from aqueous solutions. Tamarind seeds were activated by heat treatment and with concentrated sulfuric acid (98% w/w). The parameters investigated include initial pH, contact time, initial Cr(VI) concentration, and adsorbent dosage. The adsorption of Cr(VI) was found to be maximum at low values of initial pH in the range of 1–3. The adsorption process of Cr(VI) was tested with Langmuir and Freundlich isotherm models. Application of the Langmuir isotherm to the systems yielded maximum adsorption capacity of 29.08 mg g–1. The adsorption process followed second order kinetics and the corresponding rate constant was found to be 0.0026 g mg–1 min–1.
Candida albicans-secreted lipase induces injury and steatosis in immune and parenchymal cells
Authors: Paraje María Gabriela , Correa Silvia Graciela , Renna María Sol , Theumer Martín , Sotomayor Claudia Elena 
Published: September 2008

Virulence depends on opposing reactions between host and pathogen and is intrinsically linked to the host immune status. Virulence factors rely upon microbial attributes that mediate cell damage. While the activity of several Candida albicans hydrolytic enzymes is well characterized, the biological role of lipases is uncertain. In this report, we identified, isolated, and characterized a C. albicans 70 kDa lipase that exhibited maximal activity at physiological pH and temperature. We evaluated the ability of C. albicans lipase to interact with two types of mammalian host cells: macrophages, as crucial immune effector cells involved in fungal control, and hepatocytes, as examples of parenchymal cells compromised during fungal dissemination. Herein, we demonstrate for the first time that an extracellular lipase released by C. albicans directly induced cytotoxicity and promoted the deposition of lipid droplets in the cytoplasm of macrophages and hepatocytes
Revival of saprotrophic and mycorrhizal basidiomycete cultures after 20 years in cold storage in sterile water
Authors: Richter Dana L. 
Published: September 2008

Vegetatively colonized agar cores of 69 basidiomycete fungus isolates (48 species in 30 genera and 17 families) were stored at 5 °C in tubes of sterile distilled water without manipulation for 20 years. These were represented by 34 isolates of saprotrophic fungi (29 species in 19 genera) and 35 isolates of mycorrhizal fungi (19 species in 11 genera). Viability was evaluated based on revived growth on agar media at room temperature. Fifty-seven of the 69 isolates (82.6%) grew vigorously when revived after storage for 20 years; of the 34 saprotrophic fungus isolates, 30 revived (88.2%); of the 35 mycorrhizal fungus isolates, 27 revived (77.1%). Thirteen isolates of Laccaria were all viable after 20 years, indicating cold storage in sterile water to be a good method for maintaining this important genus of mycorrhizal fungi. In general, however, mycorrhizal fungus species demonstrated lower viability than saprotrophic fungi.