bluuebunny/crossref_metadata_2025 huggingface dataset:
Histone deacetylase inhibitors reduce VEGF production and induce growth suppression and apoptosis in human mantle cell lymphoma
Authors: Heider Ulrike , Kaiser Martin , Sterz Jan , Zavrski Ivana , Jakob Christian , Fleissner Claudia , Eucker Jan , Possinger Kurt , Sezer Orhan
Published: October 2005

Abstract:  Objectives: Mantle cell lymphoma (MCL) is an incurable disease with an aggressive course and novel treatment strategies are urgently needed. The purpose of this study was to evaluate the effects of histone deacetylase (HDAC) inhibitors, a new group of antiproliferative agents, on human MCL cells. Methods: Three MCL cell lines (JeKo‐1, Hbl‐2 and Granta‐519) were exposed to different concentrations of the HDAC inhibitors sodium butyrate (NaB) and suberoylanilide hydroxamic acid (SAHA) for 8–72 h. Their effects on cell viability, apoptosis induction and cell cycle proliferation were studied. Moreover, the influence of SAHA on the expression of cyclin D1, the cell cycle regulators p21 and p27 and the production of vascular endothelial growth factor (VEGF) were analyzed. Results: The HDAC inhibitors induced accumulation of acetylated histones in MCL cells. MTT assays and Annexin‐V staining showed that they potently inhibited viability in a dose‐dependent manner and induced apoptosis in all cell lines tested. Cell cycle analysis indicated that their exposure to SAHA or NaB decreased the proportion of cells in S phase and increased the proportion of cells in the G0/G1 and/or G2/M phases. Incubation with the two HDAC inhibitors resulted in downregulation of cyclin D1. SAHA lead to an upregulation of p21 in all cell lines and an upregulation of p27 in JeKo‐1 and Granta‐519 cells, while expression of p27 in Hbl‐2 was not altered. In addition, SAHA inhibited the production of the angiogenic cytokine VEGF. Treatment with NaB increased the expression of p21 in JeKo‐1 and Hbl‐2 cells, while in Granta 519 cells no effect was noted. The expression of p27 remained constant in all three cell lines after exposure to NaB. Conclusion: Based on these findings, we provide evidence that HDAC inhibitors have antiproliferative effects in MCL and may represent a promising therapeutic approach.
Assessment of the effect of endurance training on left ventricular relaxation with magnetic resonance imaging
Authors: Kivistö S. , Perhonen M. , Holmström M. , Lauerma K.
Published: October 2005

The purpose of the study was to assess the effect of endurance training on the early diastolic global and regional left ventricular (LV) relaxation with three magnetic resonance imaging (MRI) techniques.

Fourteen subjects were examined with MRI before and after 3‐month endurance training. Global early diastolic LV myocardial relaxation was assessed with mitral flow velocity mapping and regional LV early myocardial relaxation with myocardial tagging. LV end‐diastolic and end‐systolic volumes and mass were assessed with cine Magnetic resonance imaging (MRI).

Mitral flow velocity mapping analysis revealed that the time to peak early filling shortened after training (before 112±32 ms, after 97±21, P<0.05), indicating more rapid global early myocardial relaxation. LV mass increased (97±19 g, 105±18, P<0.01) and end‐systolic volume decreased (47±11 mL, 42±13, P<0.05). According to myocardial tagging analysis early myocardial relaxation in the septum and in the LV lateral wall increased (P<0.05). Regional tagging analysis showed enhanced myocardial relaxation in the basal septum (P<0.05).

Global and regional LV early diastolic relaxation improved and physiological LV hypertrophy was found after the exercise training period for 3 months in healthy sedentary subjects.
SEMIQUANTITATIVE EVALUATION OF PROTEIN RESIDUES IN FOODS USING THE FLASH RAPID CLEANING VALIDATION METHOD†
Authors: OLDS DAVID A. , FUNG DANIEL Y.C. , SHANKLIN CAROL W.
Published: October 2005

Cross‐contamination of food contact surfaces in retail foodservice establishments may result in outbreaks of foodborne illness. Traditional microbiological sampling collection methods that use swab tests or agar surface tests to monitor cross‐contamination can be time‐ and cost‐prohibitive to restaurant operators. The purpose of this study was to develop an identification protocol for residual proteins on foodservice contact surfaces using rapid chemical detection methods. The FLASH Rapid Cleaning Validation device (BioControl Systems, Bellevue, WA) was used to detect residual protein traces (exposed for 0, 2, 4, 6 and 8 h) of six different food samples (ground beef, ground turkey, ground pork, catfish, shredded cheddar cheese and shredded vegetables) on plastic cutting boards. Catalase testing was performed concurrently with FLASH validation to add further estimation of potential biological activities. Results showed that meat, cheese and vegetable samples were positive for the FLASH test and could provide semiquantification using a red–green–blue color chart. In addition, catalase testing provided more selective identification of food samples. This study demonstrates the time savings and cost‐effectiveness of using rapid methods of monitoring food safety standards in a foodservice operation.
DETECTION OF LISTERIA SP. IN MEAT AND MEAT PRODUCTS USING TECRA LISTERIA VISUAL IMMUNOASSAY AND BIOCONTROL VISUAL IMMUNOPRECIPITATE ASSAY FOR LISTERIA IMMUNOASSAYS AND A CULTURAL PROCEDURE
Authors: ARAGON‐ALEGRO LINA CASALE , WITTMANN ROBERTA MARIA , PADOVANI CARLOS ROBERTO , LANDGRAF MARIZA , DE MELO FRANCO BERNADETTE DORA GOMBOSSY , DESTRO MARIA TERESA
Published: October 2005

The routine methods for detecting Listeria sp. in foods are time consuming and involve using selective enrichments and plating on agars. In this study, the presence of Listeria sp. in 120 meat and meat product samples was investigated by two rapid immunoassays (TECRA Listeria Visual Immunoassay [VIA] and BioControl Visual Immunoprecipitate Assay [VIP] for Listeria) and a cultural procedure. The cultural method of detecting Listeria sp. followed Canada's Health Protection Branch Method, and the rapid tests followed the manufacturers' instructions. The agreement between the cultural and the rapid tests was established at a confidence limit of 95%. Seventy‐nine samples (65.8%) were Listeria sp. positive in at least one of the three tests. There was no statistically significant difference between the cultural procedure and any of the rapid immunoassays. The agreement rates between the VIA and the cultural method and between the VIP and the cultural method were 87 and 84%, respectively. Both tests – the VIA and VIP – proved to be rapid, efficient and easy to perform.
DETECTION OF SALMONELLA SPP., ESCHERICHIA COLI O157, LISTERIA MONOCYTOGENES AND CAMPYLOBACTER SPP. IN CHICKEN SAMPLES BY MULTIPLEX POLYMERASE CHAIN REACTION AND HYBRIDIZATION USING THE GENEGEN MAJOR FOOD PATHOGENS DETECTION KIT
Authors: VOLLENHOFER‐SCHRUMPF SABINE , BURESCH RONALD , UNGER GABRIELE , STAHL NICOLE , FRÄNZL GERT , SCHINKINGER MANFRED
Published: October 2005

We have applied an innovative commercial test system (the GeneGen Major Food Pathogens [MFP] Detection Kit) to detect four of the more important pathogenic microorganisms in food, Salmonella spp., Escherichia coli O157, Listeria monocytogenes and Campylobacter spp. by using multiplex polymerase chain reaction (PCR) combined with a shortened, simplified hybridization protocol on test strips. Testing 129 strains representing 23 different genera yielded no false‐positive or false‐negative results, and the limit of detection was 100 genome copies of each organism per multiplex PCR using purified genomic DNA. The kit was used for both analyses of chicken samples artificially contaminated with different numbers of the pathogens and of naturally contaminated samples. The results were compared with those obtained with standard microbiological techniques. Both methods yielded the same results in spiking experiments, detecting 1–10 cfu/25 g of the respective pathogen added. It was possible to verify the presence of all four pathogens simultaneously in one assay. The GeneGen MFP Detection Kit saves at least 2–4 days compared with standard methods. The protocol is easy to perform, and there is no need for any additional costly and sophisticated equipment, except for a thermocycler, because hybridization is carried out at ambient temperature and the results can be evaluated with the unaided eye. This enables the assay to be performed in relatively modestly equipped laboratories for both DNA‐based screening of food samples and/or confirmation of suspect colonies.
COURT OVERSIGHT AND CONVICTION UNDER MANDATORY AND NONMANDATORY DOMESTIC VIOLENCE CASE FILING POLICIES*
Authors: PETERSON RICHARD R. , DIXON JO
Published: October 2005

Research Summary:

This study examines the relative impact of mandatory and nonmandatory DV case filing policies on court oversight and conviction for misdemeanor DV cases. The prevalence and duration of court oversight are greater under a mandatory DV filing policy, whereas conviction is more likely under a nonmandatory DV filing policy. These differences remain even after controlling for legal, case processing, and defendant characteristics.

Policy Implications:

This article discusses the advantages and disadvantages of mandatory and nonmandatory DV case filing policies. Filing policies are linked to the relative priorities prosecutors place on the dual goals of court oversight and conviction.
Modeling Formation Damage by Asphaltene Deposition During Primary Oil Recovery
Authors: Wang Shaojun , Civan Faruk
Published: October 2005

Asphaltene precipitation and deposition during primary oil recovery and resulting reservoir formation damage are described by a phenomenological mathematical model. This model is applied using experimental data from laboratory core flow tests. The effect of asphaltene deposition on porosity, permeability, and the productivity of vertical wells in asphaltenic-oil reservoirs are investigated by simulation.
Model-Assisted Analysis of Simultaneous Paraffin and Asphaltene Deposition in Laboratory Core Tests
Authors: Wang Shaojun , Civan Faruk
Published: October 2005

A model for analysis and interpretation of the simultaneous deposition of paraffin and asphaltene in laboratory core tests is presented. This model incorporates the mass balance equations for the oil, gas, paraffin, and asphaltene pseudocomponents; the paraffin and asphaltene solubility and deposition models; the energy and momentum balance equations; and the porosity and permeability reduction models. This model is numerically solved and validated with two sets of laboratory experimental data. It is demonstrated that the present model satisfactorily represents the simultaneous deposition of paraffin and asphaltene and the resultant damage caused on the porosity and permeability of porous media. The model is used for determination of the various process parameters with the help of the experimental data obtained by laboratory core tests.
Use of Multiphase Meters in Process Control for Oil Field Well Testing: Performance Enhancement Through GVF Control
Authors: Marrelli Jack D. , Mohan Ram S. , Wang Shoubo , Gomez Luis , Shoham Ovadia
Published: October 2005

First oil production from a deep-water oil field is to be achieved by the installation of an initial development system (IDS). Well testing is required for field development and reservoir management. The well testing system requires high-accuracy oil and water rates to provide the data needed for decision analysis in ongoing drilling programs. The well testing system must also be integrated with other platform operations, such as well cleanup after drilling. We introduce here, the concept of a multiphase meter in series with conventional separation technology for improved process control. This feedback control loop configuration is simulated in MATLAB and shown to extend the capabilities of both technologies. The principle of gas volume fraction control in two-phase separator liquid lines is shown to be supplementary to conventional level control systems for performance enhancement of oil field well testing. Concepts demonstrated here can also be easily applied as retrofits to existing separation facilities, which show accuracy or upset problems.
Structural Behavior of a Solid Tubular Under Large Radial Plastic Expansion
Authors: Seibi A. C. , Al-Hiddabi S. , Pervez T.
Published: October 2005

The theory of metal forming has been used to study the mechanical response of a solid tubular under radial plastic expansion. A mathematical model of an expanded thin walled tube under compression has been developed in this paper. The study showed that as the friction coefficient and mandrel angle increase the drawing force and induced stresses increase. However, the final tube thickness and length were found to decrease with an increase in both parameters.
Study of a Small-Scale Fuel Cell Cogeneration System with Methanol Steam Reforming Considering Partial Load and Load Fluctuation
Authors: Obara S. , Kudo K.
Published: October 2005

Performance analysis and cost estimation are carried out for a cogeneration system consisting of a solid high-polymer-film-type fuel cell with a methanol reformer applied to individual houses. For the operation of the fuel cell under a partial load, a unique point of this system is the shifting of the driving point by the electric heater. Considering the annual energy cost for an average house in Sapporo, Japan, the energy cost of this system is shown to be 1.42 times that of conventional systems in which a cogeneration system is not installed.
Performance Analysis of a Low-Power Tangential Flow Turbine With Rotary Channel
Authors: Barbarelli Silvio , Florio Gaetano , Scornaienchi Nino Michele
Published: October 2005

A tangential flow prototype turbine with a rotating channel containing five optimized deflectors is presented. This atypical turbine configuration may be useful for application in the low ns high ds region of the Balje chart, where conventional turbines offer very poor performances. A 70kW maximum brake power, pressured-air test rig has been used for the analysis of operating characteristics, such as pressure, temperature, flow rate, and brake power. An electronic data acquisition system for automated measurement management was employed. An experimental campaign was carried out to identify the distribution of the pressure in the rotary ducts of the turbine. The results indicate the presence of a pressure gradient in the immediate vicinity of the inlet jet that is strongly attenuated when the ducts are not directly in contact with the jet.
Degradation Assessment and Fault Modes Classification Using Logistic Regression
Authors: Yan Jihong , Lee Jay
Published: October 2005

Real-time health monitoring of industrial components and systems that can detect, classify and predict impending faults is critical to reducing operating and maintenance cost. This paper presents a logistic regression based prognostic method for on-line performance degradation assessment and failure modes classification. System condition is evaluated by processing the information gathered from controllers or sensors mounted at different points in the system, and maintenance is performed only when the failure∕malfunction prognosis indicates instead of periodic maintenance inspections. The wavelet packet decomposition technique is used to extract features from non-stationary signals (such as current, vibrations), wavelet package energies are used as features and Fisher’s criteria is used to select critical features. Selected features are input into logistic regression (LR) models to assess machine performance and identify possible failure modes. The maximum likelihood method is used to determine parameters of LR models. The effectiveness and feasibility of this methodology have been illustrated by applying the method to a real elevator door system.
Optimization of Surface Grinding Operations Using Particle Swarm Optimization Technique
Authors: Asokan P. , Baskar N. , Babu K. , Prabhaharan G. , Saravanan R.
Published: October 2005

The development of comprehensive grinding process models and computer-aided manufacturing provides a basis for realizing grinding parameter optimization. The variables affecting the economics of machining operations are numerous and include machine tool capacity, required workpiece geometry, cutting conditions such as speed, feed, and depth of cut, and many others. Approximate determination of the cutting conditions not only increases the production cost, but also diminishes the product quality. In this paper a new evolutionary computation technique, particle swarm optimization, is developed to optimize the grinding process parameters such as wheel speed, workpiece speed, depth of dressing, and lead of dressing, simultaneously subjected to a comprehensive set of process constraints, with an objective of minimizing the production cost and maximizing the production rate per workpiece, besides obtaining the finest possible surface finish. Optimal values of the machining conditions obtained by particle swarm optimization are compared with the results of genetic algorithm and quadratic programming techniques.
An Experimental Study on Mechanics of Wax Removal in Pipeline
Authors: Wang Qian , Sarica Cem , Chen Tom X.
Published: October 2005

Pigging has been recognized as the most cost-effective method for preventing flow restriction by wax deposits in subsea flowlines. However, the pigging mechanics for wax removal in pipelines is still very poorly understood. A unique test facility was designed and constructed for experimental studies on the mechanics of wax removal in pipelines. The test facility consisted of a test section, a support structure, an apparatus to pull the pig through the test pipe, and a computer-based data acquisition system. The test section was 6.4m(21ft) long and was made from 0.0762m(3in.) inner diameter schedule-40 steel pipe. The mixture of commercial wax and mineral oil was cast inside the test section at different wax thickness and oil contents. A series of experiments was performed to investigate the wax removal mechanics with three different types of conventional pigs, i.e., cup, disc, and foam pigs. The experiments showed that a typical wax removal process using a pig followed four distinct phases, namely, wax breaking, plug formation, accumulation, and production phases. Wax accumulation can be very significant and is expected to be the dominating factor for the force required for moving a pig in long pipelines. As wax thickness and hardness increases, the required force to move the pig increases. The shape and material of the pig have a profound effect on the wax removal performance. While the disc pig provides the most efficient wax removal, the force requirement is excessive, especially for thicker and harder wax deposits. The wax removal performance of a cup pig is very similar to that of a disc pig. However, the cup pig can withstand higher load without mechanical damages than the disc pig. The foam pig offers the poorest wax removal performance.
Progress in Modeling of Protein Structures and Interactions
Authors: Schueler-Furman Ora , Wang Chu , Bradley Phil , Misura Kira , Baker David
Published: October 2005

The prediction of the structures and interactions of biological macromolecules at the atomic level and the design of new structures and interactions are critical tests of our understanding of the interatomic interactions that underlie molecular biology. Equally important, the capability to accurately predict and design macromolecular structures and interactions would streamline the interpretation of genome sequence information and allow the creation of macromolecules with new and useful functions. This review summarizes recent progress in modeling that suggests that we are entering an era in which high-resolution prediction and design will make increasingly important contributions to biology and medicine.
NPY/AgRP Neurons Are Essential for Feeding in Adult Mice but Can Be Ablated in Neonates
Authors: Luquet Serge , Perez Francisco A. , Hnasko Thomas S. , Palmiter Richard D.
Published: October 2005

Hypothalamic neurons that express neuropeptide Y (NPY) and agouti-related protein (AgRP) are thought to be critical regulators of feeding behavior and body weight. To determine whether NPY/AgRP neurons are essential in mice, we targeted the human diphtheria toxin receptor to the
Agrp
locus, which allows temporally controlled ablation of NPY/AgRP neurons to occur after an injection of diphtheria toxin. Neonatal ablation of NPY/AgRP neurons had minimal effects on feeding, whereas their ablation in adults caused rapid starvation. These results suggest that network-based compensatory mechanisms can develop after the ablation of NPY/AgRP neurons in neonates but do not readily occur when these neurons become essential in adults.
Quantum Coherence in an Optical Modulator
Authors: Carter S. G. , Birkedal V. , Wang C. S. , Coldren L. A. , Maslov A. V. , Citrin D. S. , Sherwin M. S.
Published: October 2005

Semiconductor quantum well electroabsorption modulators are widely used to modulate near-infrared (NIR) radiation at frequencies below 0.1 terahertz (THz). Here, the NIR absorption of undoped quantum wells was modulated by strong electric fields with frequencies between 1.5 and 3.9 THz. The THz field coupled two excited states (excitons) of the quantum wells, as manifested by a new THz frequency- and power-dependent NIR absorption line. Nonperturbative theory and experiment indicate that the THz field generated a coherent quantum superposition of an absorbing and a nonabsorbing exciton. This quantum coherence may yield new applications for quantum well modulators in optical communications.
Dating the Growth of Oceanic Crust at a Slow-Spreading Ridge
Authors: Schwartz Joshua J. , John Barbara E. , Cheadle Michael J. , Miranda Elena A. , Grimes Craig B. , Wooden Joseph L. , Dick Henry J. B.
Published: October 2005

Nineteen uranium-lead zircon ages of lower crustal gabbros from Atlantis Bank, Southwest Indian Ridge, constrain the growth and construction of oceanic crust at this slow-spreading midocean ridge. Approximately 75% of the gabbros accreted within error of the predicted seafloor magnetic age, whereas ∼25% are significantly older. These anomalously old samples suggest either spatially varying stochastic intrusion at the ridge axis or, more likely, crystallization of older gabbros at depths of ∼5 to 18 kilometers below the base of crust in the cold, axial lithosphere, which were uplifted and intruded by shallow-level magmas during the creation of Atlantis Bank.
The V-Antigen of
Yersinia
Forms a Distinct Structure at the Tip of Injectisome Needles
Authors: Mueller Catherine A. , Broz Petr , Müller Shirley A. , Ringler Philippe , Erne-Brand Françoise , Sorg Isabel , Kuhn Marina , Engel Andreas , Cornelis Guy R.
Published: October 2005

Many pathogenic bacteria use injectisomes to deliver effector proteins into host cells through type III secretion. Injectisomes consist of a basal body embedded in the bacterial membranes and a needle. In
Yersinia
, translocation of effectors requires the YopB and YopD proteins, which form a pore in the target cell membrane, and the LcrV protein, which assists the assembly of the pore. Here we report that LcrV forms a distinct structure at the tip of the needle, the tip complex. This unique localization of LcrV may explain its crucial role in the translocation process and its efficacy as the main protective antigen against plague.
Golgi Duplication in
Trypanosoma brucei
Requires Centrin2
Authors: He Cynthia Y. , Pypaert Marc , Warren Graham
Published: October 2005

Centrins are highly conserved components of the centrosome, which in the parasitic protozoan
T. brucei
comprises the basal body and nucleates the flagellum used for locomotion. Here, we found TbCentrin2 in an additional bi-lobed structure near to the Golgi apparatus. One lobe was associated with the old Golgi, and the other became associated with the newly forming Golgi as the cell grew. Depletion of TbCentrin1 inhibited duplication of the basal body, whereas depletion of TbCentrin2 also inhibited duplication of the Golgi. Thus, a Centrin2-containing structure distinct from the basal body appears to mark the site for new Golgi assembly.
Expression and Mutational Analysis of
Autographa californica
Nucleopolyhedrovirus HCF-1: Functional Requirements for Cysteine Residues
Authors: Wilson Joyce A. , Forney Scott D. , Ricci Alessondra M. , Allen Emily G. , Hefferon Kathleen L. , Miller Lois K.
Published: October 2005

The host cell-specific factor 1 gene (
hcf-1
) of the baculovirus
Autographa californica
multiple nucleopolyhedrovirus is required for efficient virus growth in TN368 cells but is dispensable for virus replication in SF21 cells. However, the mechanism of action of
hcf-1
is unknown. To begin to understand its function in virus replication we have investigated the expression and localization pattern of HCF-1 in infected cells. Analysis of virus-infected TN368 cells showed that
hcf-1
is expressed at an early time in the virus life cycle, between 2 and 12 h postinfection, and localized the protein to punctate nuclear foci. Through coprecipitation experiments we have confirmed that HCF-1 self-associates into dimers or higher-order structures. We also found that overexpression of HCF-1 repressed expression from the
hcf-1
promoter in transient reporter assays. Mutagenesis of cysteine residues within a putative RING finger domain in the amino acid sequence of HCF-1 abolished self-association activity and suggests that the RING domain may be involved in this protein-protein interaction. A different but overlapping set of cysteine residues were required for efficient gene repression activity. Functional analysis of HCF-1 mutants showed that the cysteine amino acids required for both self-association and gene repression activities of HCF-1 were also required for efficient late-gene expression and occlusion body formation in TN368 cells. Mutational analysis also identified essential charged and hydrophobic amino acids located between two of the essential cysteine residues. We propose that HCF-1 is a RING finger-containing protein whose activity requires HCF-1 self-association and gene repression activity.
NS1 Protein Secretion during the Acute Phase of West Nile Virus Infection
Authors: Macdonald Joanne , Tonry Jessica , Hall Roy A. , Williams Brent , Palacios Gustavo , Ashok Mundrigi S. , Jabado Omar , Clark David , Tesh Robert B. , Briese Thomas , Lipkin W. Ian
Published: October 2005

The West Nile virus (WNV) nonstructural protein NS1 is a protein of unknown function that is found within, associated with, and secreted from infected cells. We systematically investigated the kinetics of NS1 secretion in vitro and in vivo to determine the potential use of this protein as a diagnostic marker and to analyze NS1 secretion in relation to the infection cycle. A sensitive antigen capture enzyme-linked immunosorbent assay (ELISA) for detection of WNV NS1 (polyclonal-ACE) was developed, as well as a capture ELISA for the specific detection of NS1 multimers (4G4-ACE). The 4G4-ACE detected native NS1 antigens at high sensitivity, whereas the polyclonal-ACE had a higher specificity for recombinant forms of the protein. Applying these assays we found that only a small fraction of intracellular NS1 is secreted and that secretion of NS1 in tissue culture is delayed compared to the release of virus particles. In experimentally infected hamsters, NS1 was detected in the serum between days 3 and 8 postinfection, peaking on day 5, the day prior to the onset of clinical disease; immunoglobulin M (IgM) antibodies were detected at low levels on day 5 postinfection. Although real-time PCR gave the earliest indication of infection (day 1), the diagnostic performance of the 4G4-ACE was comparable to that of real-time PCR during the time period when NS1 was secreted. Moreover, the 4G4-ACE was found to be superior in performance to both the IgM and plaque assays during this time period, suggesting that NS1 is a viable early diagnostic marker of WNV infection.
A Live Attenuated Vaccine for Lassa Fever Made by Reassortment of Lassa and Mopeia Viruses
Authors: Lukashevich Igor S. , Patterson Jean , Carrion Ricardo , Moshkoff Dmitry , Ticer Anysha , Zapata Juan , Brasky Kathleen , Geiger Robert , Hubbard Gene B. , Bryant Joseph , Salvato Maria S.
Published: October 2005

Lassa virus (LASV) and Mopeia virus (MOPV) are closely related Old World arenaviruses that can exchange genomic segments (reassort) during coinfection. Clone ML29, selected from a library of MOPV/LASV (MOP/LAS) reassortants, encodes the major antigens (nucleocapsid and glycoprotein) of LASV and the RNA polymerase and zinc-binding protein of MOPV. Replication of ML29 was attenuated in guinea pigs and nonhuman primates. In murine adoptive-transfer experiments, as little as 150 PFU of ML29 induced protective cell-mediated immunity. All strain 13 guinea pigs vaccinated with clone ML29 survived at least 70 days after LASV challenge without either disease signs or histological lesions. Rhesus macaques inoculated with clone ML29 developed primary virus-specific T cells capable of secreting gamma interferon in response to homologous MOP/LAS and heterologous MOPV and lymphocytic choriomeningitis virus. Detailed examination of two rhesus macaques infected with this MOPV/LAS reassortant revealed no histological lesions or disease signs. Thus, ML29 is a promising attenuated vaccine candidate for Lassa fever.
Overexpression of the M2-2 Protein of Respiratory Syncytial Virus Inhibits Viral Replication
Authors: Cheng Xing , Park HyunJung , Zhou Helen , Jin Hong
Published: October 2005

The M2-2 protein of respiratory syncytial virus (RSV) is involved in regulation of viral RNA transcription and replication. Encoded by the next-to-last gene of RSV, the M2-2 open reading frame (ORF) overlaps with the upstream M2-1 ORF, suggesting that the production of the M2-2 protein might be tightly regulated during virus replication. To evaluate the effect of M2-2 overexpression on RSV replication, the M2-2 gene was separated from M2-1 by leaving it at the position prior to the M2-1 or moving it to the promoter proximal position as an independent transcriptional unit in the RSV A2 genome. Although recombinant viruses bearing the shuffled M2-2 gene were recovered and expressed higher levels of M2-2, most of these viruses grew poorly in HEp-2 cells. Sequence analysis revealed that various mutations (substitution, insertion, and deletion) occurred in the M2-2 gene, resulting in reduced M2-2 activity as measured by the RSV minigenome system. Further examination of the M2-2 sequence and its function showed that either one of the first two AUG codons located at the 5′ end of M2-2 could be used to produce a functional M2-2 protein and that deletion of the first six amino acids from its N terminus or four amino acids from its C terminus greatly reduced its function. The effect of M2-2 protein on RSV replication was also studied by examining RSV replication in cells transiently expressing M2-2. The M2-2 protein expressed at a high level completely inhibited RSV replication. These results strongly suggested that the level of the M2-2 protein produced in the infected cells is critical to RSV replication.
Sexual Transmission of Single Human Immunodeficiency Virus Type 1 Virions Encoding Highly Polymorphic Multisite Cytotoxic T-Lymphocyte Escape Variants
Authors: Milicic Anita , Edwards Charles T. T. , Hué Stéphane , Fox Julie , Brown Helen , Pillay Tilly , Drijfhout Jan W. , Weber Jonathan N. , Holmes Edward C. , Fidler Sarah J. , Zhang Hua-Tang , Phillips Rodney E.
Published: October 2005

Antigenic variation inherent in human immunodeficiency virus type 1 (HIV-1) virions that successfully instigate new infections transferred by sex has not been well defined. Yet this is the viral “challenge” which any vaccine-induced immunity must deal with. Closely timed comparisons of the virus circulating in the “donor” and that which initiates new infection are difficult to carry out rigorously, as suitable samples are very hard to get in the face of ethical hurdles. Here we investigate HIV-1 variation in four homosexual couples where we sampled blood from both parties within several weeks of the estimated transmission event. We analyzed variation within highly immunogenic HIV-1 internal proteins encoding epitopes recognized by cytotoxic Tlymphocytes (CTLs). These responses are believed to be crucial as a means of containing viral replication. In the donors we detected virions capable of evading host CTL recognition at several linked epitopes of distinct HLA class I restriction. When a donor transmitted escape variants to a recipient with whom he had HLA class I molecules in common, the recipient's CTL response to those epitopes was prevented, thus impeding adequate viral control. In addition, we show that even when HLA class I alleles are disparate in the transmitting couple, a single polymorphism can abolish CTL recognition of an overlapping epitope of distinct restriction and so confer immune escape properties to the recipient's seroconversion virus. In donors who are themselves controlling an early, acute infection, the precise timing of onward transmission is a crucial determinant of the viral variants available to compose the inoculum.
Epstein-Barr Virus Lytic Infection Is Required for Efficient Production of the Angiogenesis Factor Vascular Endothelial Growth Factor in Lymphoblastoid Cell Lines
Authors: Hong Gregory K. , Kumar Pawan , Wang Ling , Damania Blossom , Gulley Margaret L. , Delecluse Henri-Jacques , Polverini Peter J. , Kenney Shannon C.
Published: October 2005

Although Epstein-Barr virus (EBV)-associated malignancies are primarily composed of cells with one of the latent forms of EBV infection, a small subset of tumor cells containing the lytic form of infection is often observed. Whether the rare lytically infected tumor cells contribute to the growth of the latently infected tumor cells is unclear. Here we have investigated whether the lytically infected subset of early-passage lymphoblastoid cell lines (LCLs) could potentially contribute to tumor growth through the production of angiogenesis factors. We demonstrate that supernatants from early-passage LCLs infected with BZLF1-deleted virus (Z-KO LCLs) are highly impaired in promoting endothelial cell tube formation in vitro compared to wild-type (WT) LCL supernatants. Furthermore, expression of the BZLF1 gene product intransin Z-KO LCLs restored angiogenic capacity. The supernatants of Z-KO LCLs, as well as supernatants from LCLs derived with a BRLF1-deleted virus (R-KO LCLs), contained much less vascular endothelial growth factor (VEGF) in comparison to WT LCLs. BZLF1 gene expression in Z-KO LCLs restored the VEGF level in the supernatant. However, the cellular level of VEGF mRNA was similar in Z-KO, R-KO, and WT LCLs, suggesting that lytic infection may enhance VEGF translation or secretion. Interestingly, a portion of the vasculature in LCL tumors in SCID mice was derived from the human LCLs. These results suggest that lytically infected cells may contribute to the growth of EBV-associated malignancies by enhancing angiogenesis. In addition, as VEGF is a pleiotropic factor with effects other than angiogenesis, lytically induced VEGF secretion may potentially contribute to viral pathogenesis.
Adenovirus Exploits the Cellular Aggresome Response To Accelerate Inactivation of the MRN Complex
Authors: Liu Yue , Shevchenko Anna , Shevchenko Andrej , Berk Arnold J.
Published: October 2005

Results reported here indicate that adenovirus 5 exploits the cellular aggresome response to accelerate inactivation of MRE11-RAD50-NBS1 (MRN) complexes that otherwise inhibit viral DNA replication and packaging. Aggresomes are cytoplasmic inclusion bodies, observed in many degenerative diseases, that are formed from aggregated proteins by dynein-dependent retrograde transport on microtubules to the microtubule organizing center. Viral E1B-55K protein forms aggresomes that sequester p53 and MRN in transformed cells and in cells transfected with an E1B-55K expression vector. During adenovirus infection, the viral protein E4orf3 associates with MRN in promyelocytic leukemia protein nuclear bodies before MRN is bound by E1B-55K. Either E4orf3 or E4orf6 is required in addition to E1B-55K for E1B-55K aggresome formation and MRE11 export to aggresomes in adenovirus-infected cells. Aggresome formation contributes to the protection of viral DNA from MRN activity by sequestering MRN in the cytoplasm and greatly accelerating its degradation by proteosomes following its ubiquitination by the E1B-55K/E4orf6/elongin BC/Cullin5/Rbx1 ubiquitin ligase. Our results show that aggresomes significantly accelerate protein degradation by the ubiquitin-proteosome system. The observation that a normal cellular protein is inactivated when sequestered into an aggresome through association with an aggresome-inducing protein has implications for the potential cytotoxicity of aggresome-like inclusion bodies in degenerative diseases.
The P Domain of Norovirus Capsid Protein Forms a Subviral Particle That Binds to Histo-Blood Group Antigen Receptors
Authors: Tan Ming , Jiang Xi
Published: October 2005

Norovirus is the most important cause of nonbacterial acute gastroenteritis. We have shown previously that the isolated P domain containing the hinge forms a dimer and binds to histo-blood group antigen (HBGA) receptors with a low affinity (M. Tan, R. S. Hegde, and X. Jiang, J. Virol.78:6233-6242, 2004). Here, we reported that the P domain of VA387 without the hinge forms a small particle with a significantly increased receptor binding affinity. An end-linked oligopeptide containing one or more cysteines promoted P-particle formation by forming intermolecular disulfide bridges. The binding sensitivity of the P particle to HBGAs was enhanced >700-fold compared to the P dimer, which was comparable to that of virus-like particles. The binding specificity of the P particle was further confirmed by strong binding to the Caco-2 cells, a human colon carcinoma cell line. This binding enhancement was observed in the P particles of both norovirus GI and GII strains. The P particle is estimated to contain 12 P dimers, in which the P2 subdomain builds up the outer layer, while the P1 subdomain forms the internal core. Taken together, our data indicate that the P domain is involved not only in dimerization but also in polymerization of the protein during the capsid assembling. The enhanced receptor binding of the P particle reflects the intrinsic feature of the viral capsid. The easy production of the P particle and its strong binding to HBGAs suggest that the P particle is useful in studying pathogenesis and morphogenesis of norovirus and candidates for antiviral or vaccine development.
Induction of Cell Cycle Arrest by Human T-Cell Lymphotropic Virus Type 1 Tax in Hematopoietic Progenitor (CD34+) Cells: Modulation of p21cip1/waf1and p27kip1Expression
Authors: Tripp Adam , Banerjee Prabal , Sieburg Michelle , Planelles Vicente , Li Fengzhi , Feuer Gerold
Published: October 2005

Human T-cell lymphotropic virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia, an aggressive CD4+malignancy. Although HTLV-2 is highly homologous to HTLV-1, infection with HTLV-2 has not been associated with lymphoproliferative disorders. Lentivirus-mediated transduction of CD34+cells with HTLV-1 Tax (Tax1) induced G0/G1cell cycle arrest and resulted in the concomitant suppression of multilineage hematopoiesis in vitro. Tax1 induced transcriptional upregulation of the cdk inhibitors p21cip1/waf1(p21) and p27kip1(p27), and marked suppression of hematopoiesis in immature (CD34+/CD38−) hematopoietic progenitor cells in comparison to CD34+/CD38+cells. HTLV-1 infection of CD34+cells also induced p21 and p27 expression. Tax1 also protected CD34+cells from serum withdrawal-mediated apoptosis. In contrast, HTLV-2 Tax (Tax2) did not detectably alter p21 or p27 gene expression, failed to induce cell cycle arrest, failed to suppress hematopoiesis in CD34+cells, and did not protect cells from programmed cell death. A Tax2/Tax1 chimera encoding the C-terminal 53 amino acids of Tax1 fused to Tax2 (Tax221) displayed a phenotype in CD34+cells similar to that of Tax1, suggesting that unique domains encoded within the C terminus of Tax1 may account for the phenotypes displayed in human hematopoietic progenitor cells. These remarkable differences in the activities of Tax1 and Tax2 in CD34+hematopoietic progenitor cells may underlie the sharp differences observed in the pathogenesis resulting from infection with HTLV-1 and HTLV-2.
Laser-Capture Microdissection: Refining Estimates of the Quantity and Distribution of Latent Herpes Simplex Virus 1 and Varicella-Zoster Virus DNA in Human Trigeminal Ganglia at the Single-Cell Level
Authors: Wang Kening , Lau Tsz Y. , Morales Melissa , Mont Erik K. , Straus Stephen E.
Published: October 2005

There remains uncertainty and some controversy about the percentages and types of cells in human sensory nerve ganglia that harbor latent herpes simplex virus 1 (HSV-1) and varicella-zoster virus (VZV) DNA. We developed and validated laser-capture microdissection and real-time PCR (LCM/PCR) assays for the presence and copy numbers of HSV-1 gG and VZV gene 62 sequences in single cells recovered from sections of human trigeminal ganglia (TG) obtained at autopsy. Among 970 individual sensory neurons from five subjects, 2.0 to 10.5% were positive for HSV-1 DNA, with a median of 11.3 copies/positive cell, compared with 0.2 to 1.5% of neurons found to be positive by in situ hybridization (ISH) for HSV-1 latency-associated transcripts (LAT), the classical surrogate marker for HSV latency. This indicates a more pervasive latent HSV-1 infection of human TG neurons than originally thought. Combined ISH/LCM/PCR assays revealed that the majority of the latently infected neurons do not accumulate LAT to detectable levels. We detected VZV DNA in 1.0 to 6.9% of individual neurons from 10 subjects. Of the total 1,722 neurons tested, 4.1% were VZV DNA positive, with a median of 6.9 viral genomes/positive cell. After removal by LCM of all visible neurons on a slide, all surrounding nonneuronal cells were harvested and assayed: 21 copies of HSV-1 DNA were detected in ∼5,200 nonneuronal cells, while nine VZV genomes were detected in ∼14,200 nonneuronal cells. These data indicate that both HSV-1 and VZV DNAs persist in human TG primarily, if not exclusively, in a moderate percentage of neuronal cells.
Interferon-Induced Alterations in the Pattern of Parainfluenza Virus 5 Transcription and Protein Synthesis and the Induction of Virus Inclusion Bodies
Authors: Carlos T. S. , Fearns R. , Randall R. E.
Published: October 2005

Although parainfluenza virus 5 (simian virus 5 [SV5]) circumvents the interferon (IFN) response by blocking IFN signaling and by reducing the amount of IFN released by infected cells, its ability to circumvent the IFN response is not absolute. The effects of IFN on SV5 infection were examined in Vero cells, which do not produce but can respond to IFN, using a strain of SV5 (CPI−) which does not block IFN signaling. Thus, by infecting Vero cells with CPI− and subsequently treating the cells with exogenous IFN, it was possible to observe the effects that IFN had on SV5 infection in the absence of virus countermeasures. IFN rapidly (within 6 h) induced alterations in the relative levels of virus mRNA and protein synthesis and caused a redistribution of virus proteins within infected cells that led to the enhanced formation of virus cytoplasmic inclusion bodies. IFN induced a steeper gradient of mRNA transcription from the 3′ to the 5′ end of the genome and the production of virus mRNAs with longer poly(A) tails, suggesting that the processivity of the virus polymerase was altered in cells in an IFN-induced antiviral state. Additional evidence is presented which suggests that these findings also apply to the replication of strains of SV5, parainfluenza virus type 2, and mumps virus that block IFN signaling when they infect cells that are already in an IFN-induced antiviral state.
Acquisition of Macrophage Tropism during the Pathogenesis of Feline Infectious Peritonitis Is Determined by Mutations in the Feline Coronavirus Spike Protein
Authors: Rottier Peter J. M. , Nakamura Kazuya , Schellen Pepijn , Volders Haukeline , Haijema Bert Jan
Published: October 2005

In feline coronavirus (FCoV) pathogenesis, the ability to infect macrophages is an essential virulence factor. Whereas the low-virulence feline enteric coronavirus (FECV) isolates primarily replicate in the epithelial cells of the enteric tract, highly virulent feline infectious peritonitis virus (FIPV) isolates have acquired the ability to replicate efficiently in macrophages, which allows rapid dissemination of the virulent virus throughout the body. FIPV 79-1146 and FECV 79-1683 are two genetically closely related representatives of the two pathotypes. Whereas FECV 79-1683 causes at the most a mild enteritis in young kittens, FIPV 79-1146 almost invariably induces a lethal peritonitis. The virulence phenotypes correlate with the abilities of these viruses to infect and replicate in macrophages, a feature of FIPV 79-1146 but not of FECV 79-1683. To identify the genetic determinants of the FIPV 79-1146 macrophage tropism, we exchanged regions of its genome with the corresponding parts of FECV 79-1683, after which the ability of the FIPV/FECV hybrid viruses to infect macrophages was tested. Thus, we established that the FIPV spike protein is the determinant for efficient macrophage infection. Interestingly, this property mapped to the C-terminal domain of the protein, implying that the difference in infection efficiency between the two viruses is not determined at the level of receptor usage, which we confirmed by showing that infection by both viruses was equally blocked by antibodies directed against the feline aminopeptidase N receptor. The implications of these findings are discussed.
Alpha/Beta Interferons Regulate Murine Gammaherpesvirus Latent Gene Expression and Reactivation from Latency
Authors: Barton Erik S. , Lutzke Mary L. , Rochford Rosemary , Virgin Herbert W.
Published: October 2005

Alpha/beta interferon (IFN-α/β) protects the host from virus infection by inhibition of lytic virus replication in infected cells and modulation of the antiviral cell-mediated immune response. To determine whether IFN-α/β also modulates the virus-host interaction during latent virus infection, we infected mice lacking the IFN-α/β receptor (IFN-α/βR−/−) and wild-type (wt; 129S2/SvPas) mice with murine gammaherpesvirus 68 (γHV68), a lymphotropic gamma-2-herpesvirus that establishes latent infection in B cells, macrophages, and dendritic cells. IFN-α/βR−/−mice cleared low-dose intranasal γHV68 infection with wt kinetics and harbored essentially wt frequencies of latently infected cells in both peritoneum and spleen by 28 days postinfection. However, latent virus in peritoneal cells and splenocytes from IFN-α/βR−/−mice reactivated ex vivo with >40-fold- and 5-fold-enhanced efficiency, respectively, compared to wt cells. Depletion of IFN-α/β from wt mice during viral latency also significantly increased viral reactivation, demonstrating an antiviral function of IFN-α/β during latency. Viral reactivation efficiency was temporally regulated in both wt and IFN-α/βR−/−mice. The mechanism of IFN-α/βR action was distinct from that of IFN-γR, since IFN-α/βR−/−mice did not display persistent virus replication in vivo. Analysis of viral latent gene expression in vivo demonstrated specific upregulation of the latency-associated gene M2, which is required for efficient reactivation from latency, in IFN-α/βR−/−splenocytes. These data demonstrate that an IFN-α/β-induced pathway regulates γHV68 gene expression patterns during latent viral infection in vivo and that IFN-α/β plays a critical role in inhibiting viral reactivation during latency.