bluuebunny/crossref_metadata_2025 huggingface dataset:
OC8 The short‐term efficacy of osseointegrated implants in patients with non‐malignant oral mucosal disease: a case series
Authors: Hodgson TA , Lewis N , Darbar U , Welfare RD , Boulter A , Porter SR
Published: August 2006

Purpose  The spectrum of patients who may wish or warrant osseointegrated implants is increasing, despite few reports of the impact of non‐malignant oral mucosal disease upon implant placement. This report details the implant placement outcomes in three patients with pre‐existing oral mucosal disease.

Case reports  A: Four implants were placed in the lower anterior region of a 78‐year‐old female with longstanding mucous membrane pemphigoid (MMP) in 2004. The MMP had resulted in extensive cicatrisation of the upper and lower buccal and labial vestibules. One implant failed to osseointegrate, but was successfully replaced. There have been no other postplacement adverse events, despite the MMP remaining mildly active.

B: A 36‐years‐old male with orofacial granulomatosis characterised by recurrent lip swelling and gingival enlargement, had a single implant placed in the upper canine region in 2001. Although still in situ significant peri‐implant alveolar bone loss has occurred and has been stabilised by repeated debridement, local administration of topical minocycline and several courses of systemic metronidazole.

C: A 53‐years‐old female with oral manifestations of diffuse systemic sclerosis and fibrosing alveolitis had four lower anterior mandibular implants placed in 1995 to support an 8 unit bridge. One episode of peri‐implant inflammation was controlled with local debridement and topical chlorhexidine mouthrinse. The implants remain satisfactory 11 years postinsertion.

Conclusion  The short‐term failure of osseointegrated implant integration appears uncommon in patients with non‐malignant oral mucosal disease. There remains a need to establish appropriate case selection criteria and monitor outcomes.
OC9 Successful use of mycophenolate mofetil in combination with minocycline in a woman with severe predominantly oral mucous membrane pemphigoid: a case report
Authors: Salzano S , Arduino P , Zambruno G , Di Zenzo G , Baldovino S , Roccatello D , Conrotto D , Carrozzo M
Published: August 2006

Mucous membrane pemphigoid (MMP) is a group of rare, acquired, autoimmune sub epithelial blistering diseases. Diagnosis is based on clinical presentation, evidence of sub epithelial vesicles or bullae on routine histological analysis, and direct and indirect immunofluorescence studies. We present a case of widespread chronic severe oral erosions diagnosed as MMP thanks to positive ELISA anti‐BP180 NC16A. The patient was treated with topical and systemic corticosteroids, systemic azathioprine, topical cyclosporine and tacrolimus and different types of antibiotics between 2000 and 2004 with only limited and temporary disease control and severe side effects. The patient has been treated with mycophenolate mofetil (up to 2 g per day) and systemic minocycline (up to 200 mg per day) for the past 10 months, and there have been no relapses, with the complete healing of the oral ulcerations. Different studies have confirmed the essential role of autoantibodies against BP180 in the pathogenesis of MMP. Mycophenolate mofetil specifically inhibits activated lymphocytes and it has few effects on other rapidly dividing cells. Case reports and series of its use in immunobullous diseases suggest that MMF may have a role in the management of such diseases. Currently, treatment of MMP with mycophenolate mofetil and tetracyclines has not been described in the literature.
Materializing the Eighteenth Century: Dress History, Literature, and Interdisciplinary Study
Authors: Smith Chloe Wigston
Published: August 2006

Drawing on an interview with Linda Baumgarten, curator of clothing and textiles at Colonial Williamsburg, and recent interdisciplinary studies, this article considers how eighteenth‐century scholars use the history of dress in literary history and cultural studies. It explores how the study of material culture can illuminate and complicate literary history, but also how dress history comprises its own language and ideas.
James Kenney's Comedic Genius: Early Nineteenth‐century Character, Commerce, and the Arts in Raising the Wind, The World!, and Debtor and Creditor
Authors: Robinson Terry F.
Published: August 2006

Scholars have long perceived the early nineteenth century as an era of decline in the drama, a time when the literary and dramatic arts severed connections, and playwrighting for the Theatres Royal became subject wholly to popular sway. James Kenney's comedies reveal how such a view is symptomatic, in part, of the early nineteenth‐century clash between advocates for the arts and promoters of commerce. Through an exploration of character and identity formation within commercial society, Kenney interrogates the seeming opposition between the arts and commerce and exposes, instead, their interdependency. By juxtaposing romance narrative convention and the modern marketplace, he shows that the early nineteenth‐century stage was one of dynamism and growth, rather than failure and loss.
Apparent Survival Estimates for Five Species of Tropical Birds in an Endangered Forest Habitat in Western Ecuador1
Authors: Parker T. H. , Becker C. D. , Sandercock B. K. , Agreda A. E.
Published: August 2006

Estimates of annual survival are essential for addressing topics in evolutionary and conservation ecology. However, most demographic studies of land birds are based on north temperate species, and few robust estimates of survival based on mark–recapture statistics are available for continental South American birds. We used time‐since‐marking models to estimate apparent survival of adult birds from 7 yr of mist netting data in the Colonche Hills. This site is one of few remaining large tracts of premontane forest in southwestern Ecuador, and an area of high priority for avian conservation. Species with sufficient data for analysis included three hummingbirds (Adelomyia melanogenys, Heliodoxa jacula, Phaethornis baroni), a cotinga (Schiffornis turdinus), and a wren (Henicorhina leucophrys). Our parameter estimates had reduced precision because the number of recaptures was small. Probability of recapture was low in three species , and moderate in two others . Adelomyia and Phaethornis had moderate apparent survival (; probability that a bird neither died nor emigrated from our survey area in a given year). Adults of Adelomyia moved seasonally, and it is possible that permanent emigration from our survey area contributed to low estimates of apparent survival. The other three species had relatively high estimates of adult apparent survival ranging from in Heliodoxa and Schiffornis to a high of in Henicorhina.
Globalization and blood safety
Authors: Farrugia A.
Published: August 2006

Globalization may be viewed as the growing interdependence of countries worldwide through the increasing volume and variety of cross‐border transactions in goods and services, and also through the more rapid and widespread diffusion of technology. Globalization is not just an economic phenomenon, although it is frequently described as such, but includes commerce, disease and travel, and immigration, and as such it affects blood safety and supply in various ways. The relatively short travel times offered by modern aviation can result in the rapid spread of blood‐borne pathogens before measures to counteract transmission can be put in place; this would have happened with SARS if the basic life cycle of the SARS virus did not include an asymptomatic viraemia. This risk can be amplified by ecological factors which effect the spread of these pathogens once they are transferred to a naïve ecosystem, as happened with West Nile virus (WNV) in North America. The rationalization and contraction of the plasma products industry may be viewed as one aspect of globalization imposed by the remorseless inevitability of the market; the effect of this development on the safety and supply of products has yet to be seen, but the oversight and assurance of a shrinking number of players will present particular challenges. Similarly, the monopolization of technology, through patent enforcement which puts access beyond the reach of developing countries, can have an effect on blood safety. The challenges presented to blood safety by globalization are heightening the tensions between the traditional focus on the product safety – zero‐risk paradigm and the need to view the delivery of safe blood as an integrated process. As an illustration of this tension, donor deferral measures imposed by globalization‐induced risks such as vCJD and WNV have resulted in the loss of the safest and most committed portion of the blood donor population in many Western countries, leading to an increased risk to safety and supply. It is only through an appreciation of the basic needs of transfusion medicine, including the enunciation of appropriate principles to manage, rather than eliminate, risks, that the challenges imposed by globalization may be overcome.
South Africa: clinical experience with Hemopure
Authors: Levien L. J.
Published: August 2006

Bovine‐derived haemoglobin solution (HBOC‐201 – Hemopure®) was first registered for routine clinical use in South Africa for the treatment of adult surgical anaemia. This material was administered to a total of 80 patients as part of a clinical surveillance and educational program from April 2001 until October 2002, and thereafter to a further 256 patients as part of ongoing clinical education and surveillance. This paper reports the clinical details, method of administration, clinical outcome, and safety and efficacy data observed in this cohort of 336 patients. Hemopure was well‐tolerated by these patients, with a considerably lower SAE rate observed in this study than was reported in the HAEM 114 and 115 phase III clinical trials. Avoidance of blood was achieved in about 89% of patients, with blood administration limited to patients with large or rapid haemorrhage and those patients who failed to demonstrate recovery of their own red cell mass after Hemopure treatment due to the presence of underlying chronic disease states.

 As clinicians became more familiar with the product characteristics and unique physiology of haemoglobin solutions, an increasing tendency has been observed for clinicians to administer Hemopure for its tissue oxygenation effect rather than as a red cell substitute. The role of Hemopure as an enhancer of tissue oxygen delivery and its effect on wound healing, requires further properly controlled randomized prospective studies.
Transfusion‐related acute lung injury and transfusion‐associated circulatory overload
Authors: Popovsky M. A.
Published: August 2006

Pulmonary complications of transfusion were once believed to be infrequent and relatively unimportant in terms of morbidity. Transfusion‐related acute lung injury (TRALI) and transfusion‐associated circulatory overload (TACO) are now appreciated as being relatively common and clinically important. TRALI is one of the two most frequent causes of transfusion‐associated death and patients with TACO have longer hospitalizations and increased morbidity. Both entities are diagnosed primarily on clinical grounds but laboratory tests are available which can confirm or supplement the clinical impression. The high‐risk patient for TRALI has not been identified but in TACO, very young or older patients who are transfused too rapidly or with too much volume are the most vulnerable. The mechanism of TRALI is incompletely understood but antibodies in stored blood components certainly play an important role. In TACO, the problem is primarily a mechanical issue. Prompt recognition is the key to successful treatment for both entities.
Reproduction in an endemic bird of a semiarid island: a food‐mediated process
Authors: Illera Juan C. , Díaz Mario
Published: August 2006

We analyse the effects of rainfall, temperature, food availability and nest predation on the between‐year variation in reproduction of the Canary Islands stonechat Saxicola dacotiae, a bird species endemic of the semiarid island of Fuerteventura (Canary Islands, Spain). We monitored the reproductive performance and output of the species across its whole distribution area during three consecutive breeding periods, also measuring rainfall, temperature and food (arthropod) availability on the ground monthly. Rainfall varied from 27.3 mm in 2000–2001 (dry year) to 124.5 mm and 125.1 mm (average years), respectively, in the 2001–2002 and 2002–2003 breeding seasons. The onset of breeding closely matched variation in the onset of the autumn‐winter rains among years. Arthropod availability was strongly and positively related to rainfall one month before. Reproductive investment (number of clutches and clutch size) was correlated to arthropod availability both among years and among sites within years. Stonechat pairs bred once or did not breed at all in the dry year whereas they bred twice in the other two years. Clutch size was smaller in the dry year and larger in the second as compared with the first in the other two years. Reproductive investment largely determined reproductive output (number of fledglings) as there were no significant spatial or temporal variation in hatching success (90% on average) or nest predation (29% on average, mostly due to feral cats Felis catus). Within‐ and among years variability in temperature or predation did not match variability in the onset, length or reproductive investment and output recorded throughout the study years. These results suggest that variability in annual fecundity in the Canary Islands Stonechat was mainly driven by rainfall through a food‐mediated process.
Interaction between seed crypsis and habitat structure influence patch choice in a granivorous bird, the chaffinch Fringilla coelebs
Authors: Jones Katherine A. , Krebs John R. , Whittingham Mark J.
Published: August 2006

Food abundance is an important determinant in habitat and patch selection but food accessibility and detectability is less often considered. Foraging on more cryptic seeds may increase predation risk by increasing the length of head down periods. Habitat structure may interact with this as birds are less able to detect predators with their head lowered in riskier obstructed habitats. We investigated patch choice in chaffinches Fringilla coelebs foraging in obstructed and open habitats and artificially manipulated the search times of seeds by colouring them either yellow or black. One trial consisted of a choice between the conspicuous seed in the open patch, and the cryptic seed in the obstructed patch; in the second trial the treatments were reversed. Individuals were more willing to forage in the obstructed habitat when the yellow seeds were present (43% of pecks made in the obstructed patch) than when the black seeds were present (18% of pecks in the obstructed patch). Differences in search time are likely to explain this result: yellow seeds were located almost twice as fast (1.26±0.60 seconds) as black ones (2.36±0.88 seconds). This experiment shows that individual foraging decisions may be influenced not only by food abundance but by the properties of individual food items (in this case seed crypsis) and the structure of the habitat they are present in.
Daytime variation in T‐cell‐mediated immunity of Eurasian kestrelFalco tinnunculusnestlings
Authors: Martínez‐Padilla Jesús
Published: August 2006

Host‐parasite interactions are central in evolutionary and behavioural ecology. In the last few years, skin injections of the mitogen Phytohaemagglutinin (PHA) have become one of the most important and widely used in‐vivo assays of immune function in birds. However, there are no studies of the circadian variation suggesting that care should be taken interpreting results when using this technique. This 3‐year study assessed PHA responses as a function of daylight time in 310 Eurasian kestrelFalco tinnunculusnestlings at 24 days of age in Central Spain. I found that T‐cell‐mediated immunity was positively related to nestling mass and varied among years. Controlling for these variables, I also found that T‐cell‐mediated immunity decreased with the hour of sampling, and that this pattern was consistent between years. In addition, I found that at the end of the day only, T‐cell‐mediated immunity decreased with brood size. Parasites seem not to be behind this pattern, but I suggest that the cumulative effect of sibling competition during the day might explain the decrease of cellular immunity with the hour of sampling. Thus, I strongly recommend that future studies of cellular immunity should control for this potential source of variation when nestling self‐maintenance is evaluated by the PHA‐induced skin‐swelling response.
Design Improvements to a Biomass Stirling Engine Using Mathematical Analysis and 3D CFD Modeling
Authors: Mahkamov K.
Published: August 2006

A prototype of a biomass Stirling engine was developed and manufactured by an industrial company prior to the numerical investigations described in this paper. Dimensions and performance of the prototype had originally been estimated using the company’s own simplified “first-order” mathematical model of the engine’s working cycle. The manufactured engine was experimentally tested, and the results demonstrated that the power output from the machine was far less than expected. To understand what caused the engine’s low operational characteristics and to predict how to refine the design, more advanced numerical investigations of the working process of the engine were performed. This utilized a “second-order” type 5 control volumes model, together with three-dimensional computational fluid dynamics modeling. As an outcome of this study, several recommendations on to how alter the prototype’s design were forthcoming, which, in practice, allow significant improvements in the engine’s performance.
A New Approach to the Simulation of Thermal Systems
Authors: Sözbir Nedim
Published: August 2006

In this paper, thermal systems are simulated and analyzed with a new approach. Thermal system design equations can be obtained as a nonlinear algebraic equation system and then this nonlinear equation system is converted to a well-defined or non-well-defined linear equation system. The transformation of the nonlinear system equations to linear system equations is realized by using the first-order Taylor series expansion; after that, the linear system of equations of our thermal system is obtained. These linear equations are then solved by our new suggested approach. This new algorithm and conventional solution methods are applied for designing some thermal systems, such as the heat exchangers combination and the gas turbine plant using design calculations. Obtained conventional and new approach results for those samples of thermal systems are compared and interpreted.
Selection of Distributed Power-Generating Systems Based on Electric, Heating, and Cooling Loads
Authors: Kowalski Gregory J. , Zenouzi Mansour
Published: August 2006

A generalized thermodynamic model is developed to describe combined cooling, heating, and power generating systems. This model is based on reversible power generation and refrigeration devices with practical, irreversible heat exchanger processes. It provides information on a system’s performance and allows easy comparisons among different systems at different loading conditions. Using both the first and second laws as well as the carbon dioxide production rate allows one to make a first-order system assessment of its energy usage and environment impact. The consistency of the exergy destruction rate and the first law performance ensures that the thermodynamic system boundaries are correctly and completely defined. The importance of the total thermal load to the required power ratio (HLRP) as a scaling parameter is demonstrated. A number of trends for limited conditions can be delineated even though the reported results confirmed that generalized trends are not identifiable because of the systems’ complexities. The results demonstrate that the combined vapor compression∕absorption refrigeration has higher first law utilization factors and lower carbon dioxide production rate for systems with high refrigeration to total thermal load ratios for all HLRP values. Fuel cell systems outperform engine systems for large refrigeration load applications. An illustration of combining these results to an economic analysis is presented.
The Operational Mixture Limits in Engines Fueled With Alternative Gaseous Fuels
Authors: Bade Shrestha S. O. , Karim Ghazi A.
Published: August 2006

The operation of engines whether spark ignition or compression ignition on a wide range of alternative gaseous fuels when using lean mixtures can offer in principle distinct advantages. These include better economy, reduced emissions, and improved engine operational life. However, there are distinct operational mixture limits below which acceptable steady engine performance cannot be sustained. These mixture limits are usually described as the “lean operational limits,” or loosely as the ignition limits which are a function of various operational and design parameters for the engine and fuel used. Relatively simple approximate procedures are described for predicting the operational mixture limits for both spark ignition and dual fuel compression ignition engines when using a range of common gaseous fuels such as natural gas/methane, propane, hydrogen, and some of their mixtures. It is shown that good agreement between predicted and corresponding experimental values can be obtained for a range of operating conditions for both types of engines.
Genome of Invertebrate Iridescent Virus Type 3 (Mosquito Iridescent Virus)
Authors: Delhon Gustavo , Tulman Edan R. , Afonso Claudio L. , Lu Zhiqiang , Becnel James J. , Moser Bettina A. , Kutish Gerald F. , Rock Daniel L.
Published: August 2006

Iridoviruses (IVs) are classified into five genera:
Iridovirus
and
Chloriridovirus
, whose members infect invertebrates, and
Ranavirus
,
Lymphocystivirus
, and
Megalocytivirus
, whose members infect vertebrates. Until now,
Chloriridovirus
was the only IV genus for which a representative and complete genomic sequence was not available. Here, we report the genome sequence and comparative analysis of a field isolate of
Invertebrate iridescent virus type 3
(IIV-3), also known as mosquito iridescent virus, currently the sole member of the genus
Chloriridovirus
. Approximately 20% of the 190-kbp IIV-3 genome was repetitive DNA, with DNA repeats localized in 15 apparently noncoding regions. Of the 126 predicted IIV-3 genes, 27 had homologues in all currently sequenced IVs, suggesting a genetic core for the family
Iridoviridae
. Fifty-two IIV-3 genes, including those encoding DNA topoisomerase II, NAD-dependent DNA ligase, SF1 helicase, IAP, and BRO protein, are present in IIV-6 (
Chilo iridescent virus
, prototype species of the genus
Iridovirus
) but not in vertebrate IVs, likely reflecting distinct evolutionary histories for vertebrate and invertebrate IVs and potentially indicative of genes that function in aspects of virus-invertebrate host interactions. Thirty-three IIV-3 genes lack homologues in other IVs. Most of these encode proteins of unknown function but also encode IIV3-053L, a protein with similarity to DNA-dependent RNA polymerase subunit 7; IIV3-044L, a putative serine/threonine protein kinase; and IIV3-080R, a protein with similarity to poxvirus MutT-like proteins. The absence of genes present in other IVs, including IIV-6; the lack of obvious colinearity with any sequenced IV; the low levels of amino acid identity of predicted proteins to IV homologues; and phylogenetic analyses of conserved proteins indicate that IIV-3 is distantly related to other IV genera.
Phenotype-Based Identification of Host Genes Required for Replication of African Swine Fever Virus
Authors: Chang Annie C. Y. , Zsak Laszlo , Feng Yanan , Mosseri Ronen , Lu Quan , Kowalski Paul , Zsak Aniko , Burrage Thomas G. , Neilan John G. , Kutish Gerald F. , Lu Zhiqiang , Laegreid Will , Rock Daniel L. , Cohen Stanley N.
Published: August 2006

African swine fever virus (ASFV) produces a fatal acute hemorrhagic fever in domesticated pigs that potentially is a worldwide economic threat. Using an expressed sequence tag (EST) library-based antisense method of random gene inactivation and a phenotypic screen for limitation of ASFV replication in cultured human cells, we identified six host genes whose cellular functions are required by ASFV. These included three loci,
BAT3
(HLA-B-associated transcript 3),
C1qTNF
(C1q and tumor necrosis factor-related protein 6), and
TOM40
(translocase of outer mitochondrial membrane 40), for which antisense expression from a tetracycline-regulated promoter resulted in reversible inhibition of ASFV production by >99%. The effects of antisense transcription of the BAT3 EST and also of expression in the sense orientation of this EST, which encodes amino acid residues 450 to 518 of the mature BAT3 protein, were investigated more extensively. Sense expression of the BAT3 peptide, which appears to reversibly interfere with BAT3 function by a dominant negative mechanism, resulted in decreased synthesis of viral DNA and proteins early after ASFV infection, altered transcription of apoptosis-related genes as determined by cDNA microarray analysis, and increased cellular sensitivity to staurosporine-induced apoptosis. Antisense transcription of
BAT3
reduced ASFV production without affecting abundance of the virus macromolecules we assayed. Our results, which demonstrate the utility of EST-based functional screens for the detection of host genes exploited by pathogenic viruses, reveal a novel collection of cellular genes previously not known to be required for ASFV infection.
Characterization of a U
L
49-Null Mutant: VP22 of Herpes Simplex Virus Type 1 Facilitates Viral Spread in Cultured Cells and the Mouse Cornea
Authors: Duffy Carol , LaVail Jennifer H. , Tauscher Andrew N. , Wills Elizabeth G. , Blaho John A. , Baines Joel D.
Published: August 2006

Herpes simplex virus type 1 (HSV-1) virions, like those of all herpesviruses, contain a proteinaceous layer termed the tegument that lies between the nucleocapsid and viral envelope. The HSV-1 tegument is composed of at least 20 different viral proteins of various stoichiometries. VP22, the product of the U
L
49 gene, is one of the most abundant tegument proteins and is conserved among the alphaherpesviruses. Although a number of interesting biological properties have been attributed to VP22, its role in HSV-1 infection is not well understood. In the present study we have generated both a U
L
49-null virus and its genetic repair and characterized their growth in both cultured cells and the mouse cornea. While single-step growth analyses indicated that VP22 is dispensable for virus replication at high multiplicities of infection (MOIs), analyses of plaque morphology and intra- and extracellular multistep growth identified a role for VP22 in viral spread during HSV-1 infection at low MOIs. Specifically, VP22 was not required for either virion infectivity or cell-cell spread but was required for accumulation of extracellular virus to wild-type levels. We found that the absence of VP22 also affected virion composition. Intracellular virions generated by the U
L
49-null virus contained reduced amounts of ICP0 and glycoproteins E and D compared to those generated by the wild-type and U
L
49-repaired viruses. In addition, viral spread in the mouse cornea was significantly reduced upon infection with the U
L
49-null virus compared to infection with the wild-type and U
L
49-repaired viruses, identifying a role for VP22 in viral spread in vivo as well as in vitro.
The Spread of
Rice Dwarf Virus
among Cells of Its Insect Vector Exploits Virus-Induced Tubular Structures
Authors: Wei Taiyun , Kikuchi Akira , Moriyasu Yusuke , Suzuki Nobuhiro , Shimizu Takumi , Hagiwara Kyoji , Chen Hongyan , Takahashi Mami , Ichiki-Uehara Tamaki , Omura Toshihiro
Published: August 2006

Various cytopathological structures, known as inclusion bodies, are formed upon infection of cultured leafhopper cells by
Rice dwarf virus
, a member of the family
Reoviridae
. These structures include tubules of approximately 85 nm in diameter which are composed of the nonstructural viral protein Pns10 and contain viral particles. Such tubular structures were produced in heterologous non-host insect cells that expressed Pns10 of the virus. These tubules, when associated with actin-based filopodia, were able to protrude from the surface of cells and to penetrate neighboring cells. A binding assay in vitro revealed the specific binding of Pns10 to actin. Infection of clusters of cells was readily apparent 5 days after inoculation at a low multiplicity of infection with the virus, even in the presence of neutralizing antibodies. However, treatment of host cells with drugs that inhibited the elongation of actin filaments abolished the extension of Pns10 tubules from the surface of cells, with a significant simultaneous decrease in the extent of infection of neighboring cells. These results together revealed a previously undescribed aspect of the intercellular spread of
Rice dwarf virus
, wherein the virus exploits tubules composed of a nonstructural viral protein and actin-based filopodia to move into neighboring cells.
Tobacco Mosaic Virus
Movement Protein Functions as a Structural Microtubule-Associated Protein
Authors: Ashby Jamie , Boutant Emmanuel , Seemanpillai Mark , Sambade Adrian , Ritzenthaler Christophe , Heinlein Manfred
Published: August 2006

The cell-to-cell spread of
Tobacco mosaic virus
infection depends on virus-encoded movement protein (MP), which is believed to form a ribonucleoprotein complex with viral RNA (vRNA) and to participate in the intercellular spread of infectious particles through plasmodesmata. Previous studies in our laboratory have provided evidence that the vRNA movement process is correlated with the ability of the MP to interact with microtubules, although the exact role of this interaction during infection is not known. Here, we have used a variety of in vivo and in vitro assays to determine that the MP functions as a genuine microtubule-associated protein that binds microtubules directly and modulates microtubule stability. We demonstrate that, unlike MP in whole-cell extract, microtubule-associated MP is not ubiquitinated, which strongly argues against the hypothesis that microtubules target the MP for degradation. In addition, we found that MP interferes with kinesin motor activity in vitro, suggesting that microtubule-associated MP may interfere with kinesin-driven transport processes during infection.
Membrane-Bound Tomato Mosaic Virus Replication Proteins Participate in RNA Synthesis and Are Associated with Host Proteins in a Pattern Distinct from Those That Are Not Membrane Bound
Authors: Nishikiori Masaki , Dohi Koji , Mori Masashi , Meshi Tetsuo , Naito Satoshi , Ishikawa Masayuki
Published: August 2006

Extracts of vacuole-depleted, tomato mosaic virus (ToMV)-infected plant protoplasts contained an RNA-dependent RNA polymerase (RdRp) that utilized an endogenous template to synthesize ToMV-related positive-strand RNAs in a pattern similar to that observed in vivo. Despite the fact that only minor fractions of the ToMV 130- and 180-kDa replication proteins were associated with membranes, the RdRp activity was exclusively associated with membranes. A genome-sized, negative-strand RNA template was associated with membranes and was resistant to micrococcal nuclease unless treated with detergents. Non-membrane-bound replication proteins did not exhibit RdRp activity, even in the presence of ToMV RNA. While the non-membrane-bound replication proteins remained soluble after treatment with Triton X-100, the same treatment made the membrane-bound replication proteins in a form that precipitated upon low-speed centrifugation. On the other hand, the detergent lysophosphatidylcholine (LPC) efficiently solubilized the membrane-bound replication proteins. Upon LPC treatment, the endogenous template-dependent RdRp activity was reduced and exogenous ToMV RNA template-dependent RdRp activity appeared instead. This activity, as well as the viral 130-kDa protein and the host proteins Hsp70, eukaryotic translation elongation factor 1A (eEF1A), TOM1, and TOM2A copurified with FLAG-tagged viral 180-kDa protein from LPC-solubilized membranes. In contrast, Hsp70 and only small amounts of the 130-kDa protein and eEF1A copurified with FLAG-tagged non-membrane-bound 180-kDa protein. These results suggest that the viral replication proteins are associated with the intracellular membranes harboring TOM1 and TOM2A and that this association is important for RdRp activity. Self-association of the viral replication proteins and their association with other host proteins may also be important for RdRp activity.
Molecularly Cloned SHIV-1157ipd3N4: a Highly Replication- Competent, Mucosally Transmissible R5 Simian-Human Immunodeficiency Virus Encoding HIV Clade Cenv
Authors: Song R. J. , Chenine A.-L. , Rasmussen R. A. , Ruprecht C. R. , Mirshahidi S. , Grisson R. D. , Xu W. , Whitney J. B. , Goins L. M. , Ong H. , Li P.-L. , Shai-Kobiler E. , Wang T. , McCann C. M. , Zhang H. , Wood C. , Kankasa C. , Secor W. E. , McClure H. M. , Strobert E. , Else J. G. , Ruprecht R. M.
Published: August 2006

Human immunodeficiency virus type 1 (HIV-1) clade C causes >50% of all HIV infections worldwide, and an estimated 90% of all transmissions occur mucosally with R5 strains. A pathogenic R5 simian-human immunodeficiency virus (SHIV) encoding HIV clade Cenvis highly desirable to evaluate candidate AIDS vaccines in nonhuman primates. To this end, we generated SHIV-1157i, a molecular clone from a Zambian infant isolate that carries HIV clade Cenv. SHIV-1157i was adapted by serial passage in five monkeys, three of which developed peripheral CD4+T-cell depletion. After the first inoculated monkey developed AIDS at week 137 postinoculation, transfer of its infected blood to a naïve animal induced memory T-cell depletion and thrombocytopenia within 3 months in the recipient. In parallel, genomic DNA from the blood donor was amplified to generate the late proviral clone SHIV-1157ipd3. To increase the replicative capacity of SHIV-1157ipd3, an extra NF-κB binding site was engineered into its 3′ long terminal repeat, giving rise to SHIV-1157ipd3N4. This virus was exclusively R5 tropic and replicated more potently in rhesus peripheral blood mononuclear cells than SHIV-1157ipd3 in the presence of tumor necrosis factor alpha. Rhesus macaques of Indian and Chinese origin were next inoculated intrarectally with SHIV-1157ipd3N4; this virus replicated vigorously in both sets of monkeys. We conclude that SHIV-1157ipd3N4 is a highly replication-competent, mucosally transmissible R5 SHIV that represents a valuable tool to test candidate AIDS vaccines targeting HIV-1 clade C Env.
Analysis of Genetic Bottlenecks during Horizontal Transmission of
Cucumber Mosaic Virus
Authors: Ali Akhtar , Li Hongye , Schneider William L. , Sherman Diana J. , Gray Stewart , Smith Dawn , Roossinck Marilyn J.
Published: August 2006

Genetic bottlenecks may occur in virus populations when only a few individuals are transferred horizontally from one host to another, or when a viral population moves systemically from the infection site. Genetic bottlenecks during the systemic movement of an RNA plant virus population were reported previously (H. Li and M. J. Roossinck, J. Virol. 78:10582-10587, 2004). In this study we mechanically inoculated an artificial population consisting of 12 restriction enzyme marker mutants of
Cucumber mosaic virus
(CMV) onto young leaves of squash plants and used two aphid species,
Aphis gossypii
and
Myzus persicae
, to transmit the virus populations from infected source plants to healthy squash plants. Horizontal transmission by aphids constituted a significant bottleneck, as the population in the aphid-inoculated plants contained far fewer mutants than the original inoculum source. Additional experiments demonstrated that genetic variation in the artificial population of CMV is not reduced during the acquisition of the virus but is significantly reduced during the inoculation period.
Phylogenetic Analysis Reveals a Correlation between the Expansion of Very Virulent Infectious Bursal Disease Virus and Reassortment of Its Genome Segment B
Authors: Hon Chung-Chau , Lam Tsan-Yuk , Drummond Alexei , Rambaut Andrew , Lee Yiu-Fai , Yip Chi-Wai , Zeng Fanya , Lam Pui-Yi , Ng Patrick T. W. , Leung Frederick C. C.
Published: August 2006

Infectious bursal disease virus (IBDV) is a birnavirus causing immunosuppressive disease in chickens. Emergence of the very virulent form of IBDV (vvIBDV) in the late 1980s dramatically changed the epidemiology of the disease. In this study, we investigated the phylogenetic origins of its genome segments and estimated the time of emergence of their most recent common ancestors. Moreover, with recently developed coalescence techniques, we reconstructed the past population dynamics of vvIBDV and timed the onset of its expansion to the late 1980s. Our analysis suggests that genome segment A of vvIBDV emerged at least 20 years before its expansion, which argues against the hypothesis that mutation of genome segment A is the major contributing factor in the emergence and expansion of vvIBDV. Alternatively, the phylogeny of genome segment B suggests a possible reassortment event estimated to have taken place around the mid-1980s, which seems to coincide with its expansion within approximately 5 years. We therefore hypothesize that the reassortment of genome segment B initiated vvIBDV expansion in the late 1980s, possibly by enhancing the virulence of the virus synergistically with its existing genome segment A. This report reveals the possible mechanisms leading to the emergence and expansion of vvIBDV, which would certainly provide insights into the scope of surveillance and prevention efforts regarding the disease.
Immunoglobulin G Antibody-Mediated Enhancement of Measles Virus Infection Can Bypass the Protective Antiviral Immune Response
Authors: Iankov Ianko D. , Pandey Manoj , Harvey Mary , Griesmann Guy E. , Federspiel Mark J. , Russell Stephen J.
Published: August 2006

Antibodies to viral surface glycoproteins play a crucial role in immunity to measles by blocking both virus attachment and subsequent fusion with the host cell membrane. Here, we demonstrate that certain immunoglobulin G (IgG) antibodies can also enhance the entry of measles virus (MV) into monocytes and macrophages. Antibody-dependent enhancement of infectivity was observed in mouse and human macrophages using virions opsonized by a murine monoclonal antibody against the MV hemagglutinin (H) glycoprotein, polyclonal mouse anti-MV IgG, or diluted measles-immune human sera. Neither H-specific Fab fragments nor H-specific IgM could enhance MV entry in monocytes or macrophages, indicating involvement of a Fc γ receptor (FcγR)-mediated mechanism. Preincubation with an anti-fusion protein (anti-F) monoclonal antibody or a fusion-inhibitory peptide blocked infection, indicating that a functional F protein was required for viral internalization. Classical complement pathway activation did not promote infection through complement receptors and inhibited anti-H IgG-mediated enhancement. In vivo, antibody-enhanced infection allowed MV to overcome a highly protective systemic immune response in preimmunized IfnarKo-Ge46 transgenic mice. These data demonstrate a previously unidentified mechanism that may contribute to morbillivirus pathogenesis where H-specific IgG antibodies promote the spread of MV infection among FcγR-expressing host cells. The findings point to a new model for the pathogenesis of atypical MV infection observed after immunization with formalin-inactivated MV vaccine and underscore the importance of the anti-F response after vaccination.
Interaction between Vaccinia Virus Extracellular Virus Envelope A33 and B5 Glycoproteins
Authors: Perdiguero Beatriz , Blasco Rafael
Published: August 2006

The extracellular form of vaccinia virus acquires its outer envelope by wrapping with cytoplasmic membranes that contain at least seven virus-encoded proteins, of which four are glycoproteins. We searched for interactions between the vaccinia virus A33 glycoprotein and proteins A34, A36, B5, F12, and F13. First, when
myc
epitope-tagged A33 was expressed in combination with other envelope proteins, A33 colocalized with B5 and A36, suggesting that direct A33-B5 and A33-A36 interactions occur in the absence of infection. A recombinant vaccinia virus (vA33R
myc
) was constructed by introduction of the
myc
-tagged A33 version (A33
myc
) into A33-deficient vaccinia virus. A33
myc
partially restored plaque formation and colocalized with enveloped virions in infected cells. Coimmunoprecipitation experiments with extracts of vA33R
myc
-infected cells confirmed the existence of a physical association of A33 with A36 and B5. Of these, the A33-B5 interaction is a novel finding, whereas the interaction between A33 and A36 has been previously characterized. A collection of vaccinia viruses expressing mutated versions of the B5 protein was used to investigate the domain(s) of B5 required for interaction with A33. Both the cytoplasmic domain and most of the extracellular domain, but not the transmembrane domain, of the B5 protein were dispensable for binding to A33. Mutations in the extracellular portions of B5 and A33 that enhance extracellular virus release did not affect the interaction between the two. In contrast, substituting the B5 transmembrane domain with that of the vesicular stomatitis virus G glycoprotein prevented the association with A33. Immunofluorescence experiments on virus mutants indicated that B5 is required for efficient targeting of A33 into enveloped virions. These results point to the transmembrane domain of B5 as the major determinant of the A33-B5 interaction and demonstrate that protein-protein interactions are crucial in determining the composition of the virus envelope.
The Envelope G3L Protein Is Essential for Entry of Vaccinia Virus into Host Cells
Authors: Izmailyan Ruzan A. , Huang Cheng-Yen , Mohammad Shamim , Isaacs Stuart N. , Chang Wen
Published: August 2006

The vaccinia virus G3L/WR079 gene encodes a conserved protein with a predicted transmembrane domain. Our proteomic analyses of vaccinia virus revealed that G3L protein is incorporated into intracellular mature virus; however, the function of G3L protein in the vaccinia virus life cycle has not been investigated. In this study, a recombinant vaccinia virus, viG3L, expressing G3L protein under IPTG (isopropyl-β-
d
-thiogalactopyranoside) regulation was constructed. Under permissive conditions when G3L protein was expressed, the vaccinia virus life cycle proceeded normally, resulting in plaque formation in BSC40 cells. In contrast, under nonpermissive conditions when G3L protein expression was repressed, no plaques were formed, showing that G3L protein is essential for vaccinia virus growth in cell cultures. In infected cells when G3L protein was not expressed, the formation of intracellular mature virus (IMV) and cell-associated enveloped virus occurred normally, showing that G3L protein is not required for virion morphogenesis. IMV particles containing (G3L
+
) or lacking (G3L
−
) G3L protein were purified and were found to be indistinguishable on microscopic examination. Both G3L
+
and G3L
−
IMV bound to HeLa cells; however, G3L
−
IMV failed to enter the cells, showing that G3L protein is required for IMV penetration into cells. Finally, G3L protein was required for fusion of the infected cells under low-pH treatment. Thus, our results provide direct evidence that G3L is an essential component of the vaccinia virus fusion complex, in addition to the previously reported A28, H2, L5, A21, and A16 proteins.
Rolling-Circle Replication of an Animal Circovirus Genome in a Theta-Replicating Bacterial Plasmid in
Escherichia coli
Authors: Cheung Andrew K.
Published: August 2006

A bacterial plasmid containing 1.75 copies of double-stranded porcine circovirus (PCV) DNA in tandem (0.8 copy of PCV type 1 [PCV1], 0.95 copy of PCV2) with two origins of DNA replication (Ori) yielded three different DNA species when transformed into
Escherichia coli
: the input construct, a unit-length chimeric PCV1
Rep
/PCV2
Cap
genome with a composite Ori but lacking the plasmid vector, and a molecule consisting of the remaining 0.75 copy PCV1
Cap
/PCV2
Rep
genome with a different composite Ori together with the bacterial plasmid. Replication of the input construct was presumably via the theta replication mechanism utilizing the ColE
1
Ori, while characteristics of the other two DNA species, including a requirement of two PCV Oris and the virus-encoded replication initiator Rep protein, suggest they were generated via the rolling-circle copy-release mechanism. Interestingly, the PCV-encoded Rep′ protein essential for PCV DNA replication in mammalian cells was not required in bacteria. The fact that the Rep′ protein function(s) can be compensated by the bacterial replication machinery to support the PCV DNA replication process echoes previous suggestions that circular single-stranded DNA animal circoviruses, plant geminiviruses, and nanoviruses may have evolved from prokaryotic episomal replicons.
Purified Feline and Canine Transferrin Receptors Reveal Complex Interactions with the Capsids of Canine and Feline Parvoviruses That Correspond to Their Host Ranges
Authors: Palermo Laura M. , Hafenstein Susan L. , Parrish Colin R.
Published: August 2006

The cell infection processes and host ranges of canine parvovirus (CPV) and feline panleukopenia virus (FPV) are controlled by their capsid interactions with the transferrin receptors (TfR) on their host cells. Here, we expressed the ectodomains of wild-type and mutant TfR and tested those for binding to purified viral capsids and showed that different naturally variant strains of the viruses were associated with variant interactions with the receptors which likely reflect the optimization of the viral infection processes in the different hosts. While all viruses bound the feline TfR, reflecting their tissue culture host ranges, a naturally variant mutant of CPV (represented by the CPV type-2b strain) that became the dominant virus worldwide in 1979 showed significantly lower levels of binding to the feline TfR. The canine TfR ectodomain did not bind to a detectable level in the in vitro assays, but this appears to reflect the naturally low affinity of that interaction, as only low levels of binding were seen when the receptor was expressed on mammalian cells; however, that was sufficient to allow endocytosis and infection. The apical domain of the canine TfR controls the specific interaction with CPV capsids, as a canine TfR mutant altering a glycosylation site in that domain bound FPV, CPV-2, and CPV-2b capsids efficiently. Enzymatic removal of the N-linked glycans did not allow FPV binding to the canine TfR, suggesting that the protein sequence difference is itself important. The purified feline TfR inhibited FPV and CPV-2 binding and infection of feline cells but not CPV-2b, indicating that the receptor binding may be able to prevent the attachment to the same receptor on cells.