Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| development of an internal control for the detection of the african swine fever virus by pcr. | for the detection of african swine fever virus (asfv) by polymerase chain reaction (pcr) in clinical samples, an internal control was constructed to identify false negative results in each reaction. the internal control was designed in such a way that the same primer pair was used to amplify the internal control and the target dna which were differentiated by size. the lower detection limit was reached at about 30 internal control dna copies and about 50 genomic asfv dna copies. the use of the i ... | 2002 | 12144776 |
| structure-based combinatorial protein engineering (scope). | presented here is the development a semi-rational protein engineering approach that uses information from protein structure coupled with established dna manipulation techniques to design and create multiple crossover libraries from non-homologous genes. the utility of structure-based combinatorial protein engineering (scope) was demonstrated by its application to two distantly related members of the x-family of dna polymerases: rat dna polymerase beta (pol beta) and african swine fever virus dna ... | 2002 | 12206782 |
| the african swine fever virus protein j4r binds to the alpha chain of nascent polypeptide-associated complex. | the african swine fever virus (asfv) j4r protein is expressed late during the virus replication cycle and is present in both the nucleus and the cytoplasm of infected cells. by using the yeast two-hybrid system, direct binding, and coprecipitation from cells, we showed that the j4r protein binds to the alpha chain of nascent polypeptide-associated complex (alpha nac). confocal microscopy indicated that a proportion of j4r and alpha nac interact in areas close to the plasma membrane, as well as t ... | 2002 | 12208975 |
| changes in macrophages in spleen and lymph nodes during acute african swine fever: expression of cytokines. | to gain further insight into the pathogenesis of african swine fever (asf), the cytokine expression by macrophages in spleen and lymph nodes were examined. twenty-one piglets were inoculated with the highly virulent isolate spain-70 of asf virus and killed in groups at 1-7 post-inoculation days (pid). an increase in the immunohistochemical detection of proinflammatory monokines in spleen and renal and gastrohepatic lymph nodes is reported, along with an increase in the serum levels of tnf-alpha ... | 2002 | 12406651 |
| african swine fever virus polyproteins pp220 and pp62 assemble into the core shell. | african swine fever virus (asfv), a complex enveloped dna virus, expresses two polyprotein precursors, pp220 and pp62, which after proteolytic processing give rise to several major components of the virus particle. we have analyzed the structural role of polyprotein pp62, the precursor form of mature products p35 and p15, in virus morphogenesis. densitometric analysis of one- and two-dimensional gels of purified virions showed that proteins p35 and p15, as well as the pp220-derived products, are ... | 2002 | 12438573 |
| novel swine virulence determinant in the left variable region of the african swine fever virus genome. | previously we have shown that the african swine fever virus (asfv) nl gene deletion mutant e70deltanl is attenuated in pigs. our recent observations that nl gene deletion mutants of two additional pathogenic asfv isolates, malawi lil-20/1 and pr4, remained highly virulent in swine (100% mortality) suggested that these isolates encoded an additional virulence determinant(s) that was absent from e70. to map this putative virulence determinant, in vivo marker rescue experiments were performed by in ... | 2002 | 11884534 |
| african swine fever virus iap-like protein induces the activation of nuclear factor kappa b. | african swine fever virus (asfv) encodes a homologue of the inhibitor of apoptosis (iap) that promotes cell survival by controlling the activity of caspase-3. here we show that asfv iap is also able to activate the transcription factor nf-kappab. thus, transient transfection of the viral iap increases the activity of an nf-kappab reporter gene in a dose-responsive manner in jurkat cells. similarly, stably transfected cells expressing asfv iap have elevated basal levels of c-rel, an nf-kappab-dep ... | 2002 | 11907233 |
| regulation of apoptosis in african swine fever virus-infected macrophages. | a number of viruses have evolved antiapoptotic mechanisms to promote infected-cell survival, either to ensure efficient productive viral replication or to promote long-term survival of virus-infected cells. recent studies identified critical african swine fever virus genes involved in the complex regulation of asfv-host interactions. here we review the present knowledge of the recently identified asfv genes with special attention to those which affect viral virulence, host range, and pathogenesi ... | 2002 | 12805900 |
| repression of african swine fever virus polyprotein pp220-encoding gene leads to the assembly of icosahedral core-less particles. | african swine fever virus (asfv) polyprotein pp220, encoded by the cp2475l gene, is an n-myristoylated precursor polypeptide that, after proteolytic processing, gives rise to the major structural proteins p150, p37, p34, and p14. these proteins localize at the core shell, a matrix-like virus domain placed between the dna-containing nucleoid and the inner envelope. in this study, we have examined the role of polyprotein pp220 in virus morphogenesis by means of an asfv recombinant, v220i, containi ... | 2002 | 11861832 |
| the g5r (d250) gene of african swine fever virus encodes a nudix hydrolase that preferentially degrades diphosphoinositol polyphosphates. | the african swine fever virus (asfv) g5r gene encodes a protein containing a nudix hydrolase motif which in terms of sequence appears most closely related to the mammalian diadenosine tetraphosphate (ap4a) hydrolases. however, purified recombinant g5r protein (g5rp) showed a much wider range of nucleotide substrate specificity compared to eukaryotic ap4a hydrolases, having highest activity with gtp, followed by adenosine 5'-pentaphosphate (p5a) and dgtp. diadenosine and diguanosine nucleotides w ... | 2002 | 11773415 |
| detection of porcine teschoviruses and enteroviruses by lightcycler real-time pcr. | porcine picornaviruses comprising at least 23 serotypes grouped into six species were described as causative agents of neurological disorders, reproductive failure, and aphthae-like dermal lesions of swine. other viruses such as classical swine fever virus (csfv), african swine fever virus, pseudorabies virus (prv), vesicular stomatitis virus, vesicular exanthema virus, porcine respiratory and reproductive syndrome virus, and porcine parvovirus (ppv) may cause diseases with similar clinical symp ... | 2003 | 14500127 |
| high-pressure freezing in the study of animal pathogens. | high-pressure freezing is applicable to both morphological and immunocytochemical studies. we are investigating the morphogenesis of foot-and-mouth disease virus and african swine fever virus by the use of high-pressure freezing of infected cells. foot-and-mouth disease virus particles are not detected in sections of conventionally immersion-fixed infected cells, but when the cells are prepared by high-pressure freezing, newly formed virions are readily seen throughout the cell. we report two me ... | 2003 | 14516363 |
| evaluation of the antiviral and antimicrobial activities of triterpenes isolated from euphorbia segetalis. | a phytochemical reinvestigation of the whole plant of euphorbia segetalis yielded five tetracyclic triterpenes: 3beta-hydroxy-cycloart-25-en-24-one (1), cycloart-25-ene-3beta,24-diol (2), cycloart-23-ene-3beta,25-diol (3), lanosta-7,9(11),24-trien-3beta-ol (4) and lanosta-7,9(11),24(31)-trien-3beta-ol (5). beta-acetoxy-cycloart-25-en-24-one (1a) and glutinol (6), lupenone (7), dammaranodienol (9), cycloartenol acetate (10), 24-methylenecycloartanol acetate (11) and beta-sitosterol (12), isolated ... | 2003 | 14526920 |
| evidence for the evolution of ascoviruses from iridoviruses. | ascoviruses (family ascoviridae) are large, enveloped, double-stranded (ds)dna viruses that attack lepidopteran larvae and pupae, and are unusual in that they are transmitted by parasitic wasps during oviposition. previous comparisons of dna polymerase sequences from vertebrate and invertebrate viruses suggested that ascoviruses are closely related to iridoviruses. this relationship was unexpected because these viruses differ markedly in virion symmetry, genome configuration and cellular patholo ... | 2003 | 14573805 |
| expression at mrna level of cytokines and a238l gene in porcine blood-derived macrophages infected in vitro with african swine fever virus (asfv) isolates of different virulence. | porcine macrophage cultures were infected with two asfv isolates of variable virulence and mrna levels of several relevant macrophage-derived cytokines were quantified by real time pcr. at six hours post infection, a clear enhancement of mrna expression of tnfalpha, il6, il12 and il15 was observed in macrophages infected with the low virulent asfv/nh/p68 (nhv) when compared to those infected with the highly virulent asfv/l60 (l60). the sequence of the a238l gene homologue to the cellular ikappab ... | 2003 | 14579171 |
| expression of porcine cd163 on monocytes/macrophages correlates with permissiveness to african swine fever infection. | monocytes-macrophages, the target cells of african swine fever virus (asfv) are highly heterogeneous in phenotype and function. in this study, we have investigated the correlation between the phenotype of specific populations of porcine macrophages and their permissiveness to asfv infection. bone marrow cells and fresh blood monocytes were less susceptible to in vitro infection by asfv than more mature cells, such as alveolar macrophages. facs analyses of monocytes using a panel of mabs specific ... | 2003 | 14648288 |
| highly sensitive pcr assay for routine diagnosis of african swine fever virus in clinical samples. | this work provides a novel, highly sensitive, hot start pcr method for rapid and specific detection of african swine fever virus (asfv) that can be used as a routine diagnostic test for asfv in surveillance, control, and eradication programs. a confirmatory test of the specificity of this method based on restriction endonuclease analysis was also developed. | 2003 | 12958285 |
| development of a taqman pcr assay with internal amplification control for the detection of african swine fever virus. | a closed-tube polymerase chain reaction (pcr) was developed to allow the rapid detection of african swine fever virus (asfv) dna. this assay targets the vp72 gene of asfv and uses the 5'-nuclease assay (taqman) system to detect pcr amplicons, avoiding tube opening and potential cross-contamination of post-pcr products. an artificial mimic was engineered with the taqman probe site replaced by a larger irrelevant dna fragment allowing discrimination from asfv by using two-colour taqman probe repor ... | 2003 | 12445938 |
| membrane association facilitates the correct processing of pp220 during production of the major matrix proteins of african swine fever virus. | the african swine fever (asf) virus polyprotein pp220 is processed at gly-gly-x sites by a virally encoded sumo-like protease to produce matrix proteins p150, p37, p34, and p14. four gly-gly-x sites are used to produce the matrix proteins, but the polyprotein contains an additional 15 sites potentially recognized by the protease. this study shows that cleavage occurs at many, if not all, gly-gly-x sites, and at steady state, p150 and p34 are minor products of processing. significantly, only the ... | 2003 | 12525602 |
| dna polymerase x of african swine fever virus: insertion fidelity on gapped dna substrates and ap lyase activity support a role in base excision repair of viral dna. | dna polymerase x (pol x) from african swine fever virus (asfv) is the smallest naturally ocurring dna-directed dna polymerase (174 amino acid residues) described so far. previous biochemical analysis has shown that asfv pol x is a highly distributive, monomeric enzyme, lacking a proofreading 3'-5' exonuclease. also, asfv pol x binds intermediates of the single-nucleotide base excision repair (ber) process, and is able to efficiently repair single-nucleotide gapped dna. in this work, we perform a ... | 2003 | 12595253 |
| polyprotein processing protease of african swine fever virus: purification and biochemical characterization. | the purified recombinant african swine fever virus polyprotein processing protease cleaves the two gg-x sites in polyprotein pp62 with the same efficiency. cleavage at the site that is first recognized in vivo is not a requisite for cleavage at the second site, suggesting the existence of mechanisms that control the ordered processing of the polyprotein during infection. | 2003 | 12634404 |
| genotyping field strains of african swine fever virus by partial p72 gene characterisation. | a pcr-based sequencing method was developed which permits detection and characterization of african swine fever virus (asfv) variants within 5 and 48 h, respectively, of receipt of a clinical specimen. amplification of a 478 bp fragment corresponding to the c-terminal end of the p72 gene, confirms virus presence with genetic characterization being achieved by nucleotide sequence determination and phylogenetic analysis. the method was applied to 55 viruses including those representative of the ma ... | 2003 | 12664294 |
| african swine fever virus proteinase is essential for core maturation and infectivity. | african swine fever virus (asfv) encodes two polyprotein precursors named pp220 and pp62 that are sequentially processed during viral infection, giving rise to six major structural proteins. these reside at the core shell, a matrix domain located between the endoplasmic reticulum-derived inner envelope and the dna-containing nucleoid. proteolytic processing of the polyprotein precursors is catalyzed by the viral proteinase ps273r, a cysteine proteinase that shares sequence similarity with the su ... | 2003 | 12719549 |
| cutaneous lesions in experimental acute and subacute african swine fever: an immunohistopathological and ultrastructural study. | histopathological, immunohistochemical and ultrastructural cutaneous changes are described in acute and subacute forms of experimental african swine fever (asf). fourteen 3-month-old large white cross pigs were infected intramuscularly with the dominican republic 78 (dr78) asf virus isolate and euthanized in pairs on alternatives days (3 to 17) post-inoculation (dpi). three pigs were found dead at 8, 10 and 13 dpi, respectively. antibodies against viral antigen vp73, human fibrinogen, glycoprote ... | 2003 | 12756955 |
| african swine fever and classical swine fever: a review of the pathogenesis. | this paper describes major pathogenetic mechanisms of african and classical swine fever virus infections. the interactions between both viruses and the monocyte-macrophage-system result in the release of mediator molecules, which are important for the further progression of the diseases. the causes of the thrombocytopenia and the mechanisms of the haemorrhages, which are characteristic in both infections, are described. apoptotic cell death is regarded as the predominant cause of lymphopenia in ... | 2003 | 12756959 |
| [ubiquitin-proteasome pathway and virus infection]. | ubiquitin is highly conserved 76 amino acid protein found in all eukaryotic organisms and ubiquitin-proteasome pathway (upp) plays a very important role in regulated non-lysosomal atp dependent protein degradation. this pathway participates in or regulates numerous cellular processes, such as selective protein degradation, cell cycle progression, apoptosis, signal transduction, transcriptional regulation, receptor control by endocytosis, immune response and the processing of antigens. neverthele ... | 2004 | 15969100 |
| codon-optimized cloning, expression and characertization of the c-terminal region of human apoptotic protein gadd34 in escherichia coli. | the human gadd34 (growth arrest and dna damage-inducible 34) is the product of an apoptosis- and dna-damage-inducible gene. the c-terminus domain of gadd34 is highly homologous to hsv-1 gamma-1 34.5, hsv-2 and the african swine fever virus virulence-associated factor nl-s. among these viral proteins, hsv-1 gamma 34.5 protein is known to prevent apoptosis of viral-infected cells. because of the difficulty in expressing gadd34 protein or any of its fragments, including the c-terminus (amino acids ... | 2004 | 14657671 |
| apoptosis of thymocytes in experimental african swine fever virus infection. | this paper report on the lesions occurred in the thymus in experimental acute african swine fever (asf). twenty-one pigs were inoculated with the highly virulent asf virus (asfv) isolate spain-70. animals were slaughtered from 1 to 7 days post infection (dpi). three animals with similar features were used as controls. thymus samples were fixed in 10% buffered formalin solution for histological and immunohistochemical study and in 2.5% glutaraldehyde for ultrastructural examination. for immunohis ... | 2004 | 14702174 |
| the cd2v protein of african swine fever virus interacts with the actin-binding adaptor protein sh3p7. | the predicted extracellular domain of the cd2v protein of african swine fever virus (asfv) shares significant similarity to that of the cd2 protein in t cells but has a unique cytoplasmic domain of unknown function. here we have shown that cd2v is expressed as a glycoprotein of approximately 105 kda in asfv-infected cells. in the absence of an extracellular ligand, the majority of cd2v appears to localize to perinuclear membrane compartments. furthermore, we have shown using the yeast two-hybrid ... | 2004 | 14718626 |
| african swine fever virus multigene family 360 and 530 genes affect host interferon response. | african swine fever virus (asfv) multigene family 360 and 530 (mgf360/530) genes affect viral growth in macrophage cell cultures and virulence in pigs (l. zsak, z. lu, t. g. burrage, j. g. neilan, g. f. kutish, d. m. moore, and d. l. rock, j. virol. 75:3066-3076, 2001). the mechanism by which these novel genes affect virus-host interactions is unknown. to define mgf360/530 gene function, we compared macrophage transcriptional responses following infection with parental asfv (pr4) and an mgf360/5 ... | 2004 | 14747550 |
| african swine fever virus multigene family 360 genes affect virus replication and generalization of infection in ornithodoros porcinus ticks. | recently, we reported that african swine fever virus (asfv) multigene family (mgf) 360 and 530 genes are significant swine macrophage host range determinants that function by promoting infected-cell survival. to examine the function of these genes in asfv's arthropod host, ornithodoros porcinus porcinus, an mgf360/530 gene deletion mutant (pr4delta35) was constructed from an asfv isolate of tick origin, pr4. pr4delta35 exhibited a significant growth defect in ticks. the deletion of six mgf360 an ... | 2004 | 14963141 |
| neutralizing antibodies to african swine fever virus proteins p30, p54, and p72 are not sufficient for antibody-mediated protection. | although antibody-mediated immune mechanisms have been shown to be important in immunity to asf, it remains unclear what role virus neutralizing antibodies play in the protective response. virus neutralizing epitopes have been identified on three viral proteins, p30, p54, and p72. to evaluate the role(s) of these proteins in protective immunity, pigs were immunized with baculovirus-expressed p30, p54, p72, and p22 from the pathogenic african swine fever virus (asfv) isolate pr4. asfv specific ne ... | 2004 | 14980493 |
| the subcellular distribution of multigene family 110 proteins of african swine fever virus is determined by differences in c-terminal kdel endoplasmic reticulum retention motifs. | african swine fever virus (asfv) is a large double-stranded dna virus that replicates in discrete areas in the cytosol of infected cells called viral factories. recent studies have shown that assembling virions acquire their internal envelopes through enwrapment by membranes derived from the endoplasmic reticulum (er). however, the mechanisms that underlie the formation of viral factories and progenitor viral membranes are as yet unclear. analysis of the published genome of the virus revealed a ... | 2004 | 15016891 |
| exceptionally diverse morphotypes and genomes of crenarchaeal hyperthermophilic viruses. | the remarkable diversity of the morphologies of viruses found in terrestrial hydrothermal environments with temperatures >80 degrees c is unprecedented for aquatic ecosystems. the best-studied viruses from these habitats have been assigned to novel viral families: fuselloviridae, lipothrixviridae and rudiviridae. they all have double-stranded dna genomes and infect hyperthermophilic crenarchaea of the orders sulfolobales and thermoproteales. representatives of the different viral families share ... | 2004 | 15046572 |
| african swine fever virus structural protein p54 is essential for the recruitment of envelope precursors to assembly sites. | the assembly of african swine fever virus (asfv) at the cytoplasmic virus factories commences with the formation of precursor membranous structures, which are thought to be collapsed cisternal domains recruited from the surrounding endoplasmic reticulum (er). this report analyzes the role in virus morphogenesis of the structural protein p54, a 25-kda polypeptide encoded by the e183l gene that contains a putative transmembrane domain and localizes at the er-derived envelope precursors. we show th ... | 2004 | 15047843 |
| switching on and off the cell death cascade: african swine fever virus apoptosis regulation. | 2004 | 15171607 | |
| modulation of p53 cellular function and cell death by african swine fever virus. | modulation of the activity of tumor suppressor p53 is a key event in the replication of many viruses. we have studied the function of p53 in african swine fever virus (asfv) infection by determining the expression and activity of this transcription factor in infected cells. p53 levels are increased at early times of infection and are maintained throughout the infectious cycle. the protein is transcriptionally active, stabilized by phosphorylation, and localized in the nucleus. p53 induces the ex ... | 2004 | 15194793 |
| african swine fever virus proteins involved in evading host defence systems. | african swine fever virus (asfv) can cause an acutely fatal haemorrhagic fever in domestic pigs although in its natural hosts, warthogs, bushpigs and the soft tick vector, ornithodoros moubata, asfv causes inapparent persistent infections. the virus is a large, cytoplasmic, double-stranded dna virus which has a tropism for macrophages. as it is the only member of the asfarviridae family, asfv encodes many novel genes not encoded by other virus families. the ability of the virus to persist in its ... | 2004 | 15207450 |
| identification of cellular proteins modified in response to african swine fever virus infection by proteomics. | changes in gene expression are produced in cells as a consequence of virus infections. in the present work, we used proteomic technology to globally examine african swine fever virus (asfv)-infected vero cells searching for infection-associated proteins in order to determine target proteins for pathogenesis studies. we studied the alterations in cellular protein profile after asfv infection by two-dimensional electrophoresis, identifying the modified cellular proteins by matrix-assisted laser de ... | 2004 | 15221765 |
| the african swine fever virus dynein-binding protein p54 induces infected cell apoptosis. | a specific interaction of asfv p54 protein with 8 kda light chain cytoplasmic dynein (dlc8) has been previously characterized and this interaction is critical during virus internalization and transport to factory sites. during early phases of infection, the virus induces the initiation of apoptosis triggering activation of caspase-9 and -3. to analyze the role of the structural protein p54 in apoptosis, transient expression experiments of p54 in vero cells were carried out which resulted in effe ... | 2004 | 15225638 |
| transport of african swine fever virus from assembly sites to the plasma membrane is dependent on microtubules and conventional kinesin. | african swine fever virus (asfv) is a large dna virus that assembles in perinuclear viral factories located close to the microtubule organizing center. in this study, we have investigated the mechanism by which asfv reaches the cell surface from the site of assembly. immunofluorescence microscopy revealed that at 16 h postinfection, mature virions were aligned along microtubules. furthermore, virus movement to the cell periphery was inhibited when microtubules were depolymerized by nocodazole. i ... | 2004 | 15254171 |
| the c-type lectin homologue gene (ep153r) of african swine fever virus inhibits apoptosis both in virus infection and in heterologous expression. | the open reading frame ep153r of african swine fever virus (asfv) encodes a nonessential protein that has been involved in the hemadsorption process induced in virus-infected cells. by the use of a virus deletion mutant lacking the ep153r gene, we have detected, in several virus-sensitive cells, increased levels of caspase-3 and cell death as compared with those obtained after infection with the parental ba71v strain. both transient and stable expression of the ep153r gene in vero or cos cells r ... | 2004 | 15262504 |
| characterization of pathogenic and non-pathogenic african swine fever virus isolates from ornithodoros erraticus inhabiting pig premises in portugal. | ten african swine fever virus isolates from the soft tick ornithodoros erraticus collected on three farms in the province of alentejo in portugal were characterized by their ability to cause haemadsorption (had) of red blood cells to infected pig macrophages, using restriction enzyme site mapping of the virus genomes and by experimental infection of pigs. six virus isolates induced haemadsorption and four were non-haemadsorbing (non-had) in pig macrophage cell cultures. the restriction enzyme si ... | 2004 | 15269356 |
| risks to farm animals from pathogens in composted catering waste containing meat. | uncooked meat may contain animal pathogens, including bovine spongiform encephalopathy, foot-and-mouth disease virus, african swine fever virus and classical swine fever virus, and to prevent outbreaks of these diseases in farm animals, the disposal of meat from catering waste is controlled under the animal by-products regulations. this paper estimates the risks to farm animals of grazing land on to which compost, produced by the composting of catering waste containing meat, has been applied. th ... | 2004 | 15311800 |
| two african swine fever virus proteins derived from a common precursor exhibit different nucleocytoplasmic transport activities. | african swine fever virus (asfv), a large icosahedral deoxyvirus, is the causative agent of an economically relevant hemorrhagic disease that affects domestic pigs. the major purpose of the present study was to investigate the nuclear transport activities of the asfv p37 and p14 proteins, which result from the proteolytic processing of a common precursor. experiments were performed by using yeast-based nucleocytoplasmic transport assays and by analysis of the subcellular localization of differen ... | 2004 | 15331706 |
| african swine fever virus inhibits induction of the stress-induced proapoptotic transcription factor chop/gadd153. | stress signaling from mitochondria and the endoplasmic reticulum (er) leads to the induction of the proapoptotic transcription factor chop/gadd153. many viruses use the er as a site of replication and/or envelopment, and this activity can lead to the activation of er stress and apoptosis. african swine fever virus (asfv) is assembled on the cytoplasmic face of the er and ultimately enveloped by er membrane cisternae. the virus also recruits mitochondria to sites of viral replication and induces ... | 2004 | 15367650 |
| a highly sensitive and specific gel-based multiplex rt-pcr assay for the simultaneous and differential diagnosis of african swine fever and classical swine fever in clinical samples. | the development and standardisation of a novel, highly sensitive and specific one-step hot start multiplex rt-pcr assay is presented for the simultaneous and differential diagnosis of african swine fever (asf) and classical swine fever (csf). the method uses two primer sets, each one specific for the corresponding virus, amplifying dna fragments different in length, allowing a gel-based differential detection of the pcr products. universal detection of asf and csf virus strains was achieved thro ... | 2004 | 15369658 |
| the viral protein a238l inhibits cyclooxygenase-2 expression through a nuclear factor of activated t cell-dependent transactivation pathway. | cyclooxygenase-2 is transiently induced upon cell activation or viral infections, resulting in inflammation and modulation of the immune response. here we report that a238l, an african swine fever virus protein, efficiently inhibits cyclooxygenase-2 gene expression in jurkat t cells and in virus-infected vero cells. transfection of jurkat cells stably expressing a238l with cyclooxygenase-2 promoter-luciferase constructs containing 5'-terminal deletions or mutations in distal or proximal nuclear ... | 2004 | 15471864 |
| co-circulation of two genetically distinct viruses in an outbreak of african swine fever in mozambique: no evidence for individual co-infection. | in 1998, domestic pigs originating from villages within a 40 km radius of ulongwe in the northern tete province of mozambique were held in a quarantine facility for a 3-month period prior to their importation into south africa. eight of a total of 25 pigs died within the first 3 weeks of quarantine of what appeared clinically and on post mortem examination to be african swine fever (asf). organs were collected and preserved in formol-glycerosaline and the presence of asf virus in these specimens ... | 2004 | 15504588 |
| an investigation into natural resistance to african swine fever in domestic pigs from an endemic area in southern africa. | a population of domestic pigs in northern mozambique with increased resistance to the pathogenic effects of african swine fever (asf) virus was identified by the high prevalence of circulating antibodies to asf virus. an attempt was made to establish whether the resistance in this population was heritable. some of these pigs were acquired and transported to a quarantine facility and allowed to breed naturally. offspring of the resistant pigs were transferred to a high security facility where the ... | 2004 | 15861893 |
| tick-borne viruses. | at least 38 viral species are transmitted by ticks. virus-tick-vertebrate host relationships are highly specific and less than 10% of all tick species (argasidae and ixodidae) are known to play a role as vectors of arboviruses. however, a few tick species transmit several (e.g. ixodes ricinus, amblyomma variegatum) or many (i. uriae) tick-borne viruses. tick-borne viruses are found in six different virus families (asfarviridae, reoviridae, rhabdoviridae, orthomyxoviridae, bunyaviridae, flaviviri ... | 2004 | 15938513 |
| adaptation of an invader assay for the detection of african swine fever virus dna. | a closed tube isothermal invader assay (third wave technologies inc., madison, wisconsin, usa) was adapted for the detection of african swine fever virus (asfv) dna. several asfv invader assays were designed successfully and tested on a real-time pcr instrument (icycler, biorad). the assay exhibiting the lowest signal/noise ratio (vp73 asfv invader assay) was analysed further using serial 10-fold dilutions of lisbon 60 asfv viral genome. the assay sensitivity was determined to be in the order of ... | 2004 | 15664044 |
| african swine fever virus infection disrupts centrosome assembly and function. | african swine fever virus (asfv) is a large, enveloped dna virus that assembles in perinuclear sites located close to the centrosome. it is reported here that the microtubule network becomes disorganized soon after the onset of viral dna replication and formation of assembly sites. asfv infection resulted in loss of gamma-tubulin and pericentrin at the centrosome; this was due to protein relocalization, but not degradation. asfv infection also inhibited the ability of the centrosome to nucleate ... | 2005 | 15722518 |
| an error-prone viral dna ligase. | our recent demonstration that dna polymerase x (pol x), the dna repair polymerase encoded by the african swine fever virus (asfv), is extremely error prone during single-nucleotide gap filling led us to hypothesize that it might contribute to genetic variability in asfv. for the infidelity of pol x to be relevant, however, the dna ligase working downstream of it would need to be capable of sealing nicks containing 3'-oh mismatches. we therefore examined the nick ligation capabilities of the asfv ... | 2005 | 15938630 |
| viruses in boar semen: detection and clinical as well as epidemiological consequences regarding disease transmission by artificial insemination. | many viruses have been reported to be present in boar semen, particularly during the viremic phase of the diseases. some of them, such foot-and-mouth disease virus, porcine reproductive and respiratory syndrome virus, swine vesicular disease virus, porcine parvovirus, picornaviruses, adenoviruses, enteroviruses, japanese encephalitis virus, pseudorabies virus, african swine fever virus and reoviruses are of particular importance and accurate monitoring prior to and during the presence of boars i ... | 2005 | 15626416 |
| preclinical diagnosis of african swine fever in contact-exposed swine by a real-time pcr assay. | a fluorogenic probe hydrolysis (taqman) pcr assay for african swine fever virus (asfv) was developed and evaluated in experimentally infected swine. this sensitive and specific one-step single-tube assay, which can be performed in 2 h or less, detected viral dna in tonsil scraping samples 2 to 4 days prior to onset of clinical disease. thus, the assay would have application for preclinical diagnosis of african swine fever and surveillance and/or emergency management of a disease outbreak. | 2005 | 15634958 |
| molecular epidemiology of african swine fever in east africa. | african swine fever (asf) a lethal, viral hemorrhagic disease of domestic pigs, first reported from east africa in 1921, is still widespread in this region. in order to assess field heterogeneity at the regional level, nucleotide sequences corresponding to the c-terminal end of the p72 gene were determined for 77 asf viruses of diverse temporal and species origin occurring in eight east african countries. the number of sites completely conserved across all east african sequences characterized in ... | 2005 | 16052280 |
| in vivo depletion of cd8+ t lymphocytes abrogates protective immunity to african swine fever virus. | to understand the mechanisms involved in protective immunity to african swine fever virus (asfv) infection, the observation that infection with the avirulent portuguese asfv isolate our/t88/3 protects outbred pigs from challenge with the virulent portuguese asfv isolate our/t88/1 was exploited. it was demonstrated that pigs exposed to our/t88/3 and then depleted of cd8+ lymphocytes were no longer fully protected from our/t88/1 challenge. this indicated that cd8+ lymphocytes play an important rol ... | 2005 | 16099902 |
| vimentin rearrangement during african swine fever virus infection involves retrograde transport along microtubules and phosphorylation of vimentin by calcium calmodulin kinase ii. | african swine fever virus (asfv) infection leads to rearrangement of vimentin into a cage surrounding virus factories. vimentin rearrangement in cells generally involves phosphorylation of n-terminal domains of vimentin by cellular kinases to facilitate disassembly and transport of vimentin filaments on microtubules. here, we demonstrate that the first stage in vimentin rearrangement during asfv infection involves a microtubule-dependent concentration of vimentin into an "aster" within virus ass ... | 2005 | 16140754 |
| intra- and inter-genotypic size variation in the central variable region of the 9rl open reading frame of diverse african swine fever viruses. | african swine fever (asf) viruses are characterised by numerous p72 genotypes, but by low levels of intra-genotypic variation, particularly in domestic pig associated genotypes. as it is precisely these viral lineages that are involved in outbreaks of the disease it is imperative that alternative, more informative gene regions be identified which are suitable for intra-genotypic resolution of relationships. to this end, the central variable region (cvr) of the 9rl open reading frame of diverse a ... | 2005 | 16175341 |
| indirect sandwich elisa for antigen detection of african swine fever virus: comparison of polyclonal and monoclonal antibodies. | two indirect, sandwich elisas are described for use in african swine fever (asf) diagnosis. one assay uses polyclonal serum raised in rabbits and guinea pigs against the cytoplasmic soluble asf virus protein and the second, a combination of monoclonal antibody raised against the vp73 protein and rabbit polyclonal serum. both assays have been shown to detect antigen of representative field strains of phylogenetically distinct groupings of asf virus but the elisa, which utilises polyclonal antiser ... | 2006 | 16182385 |
| in silico studies of the african swine fever virus dna polymerase x support an induced-fit mechanism. | the african swine fever virus dna polymerase x (pol x), a member of the x family of dna polymerases, is thought to be involved in base excision repair. kinetics data indicate that pol x catalyzes dna polymerization with low fidelity, suggesting a role in viral mutagenesis. though pol x lacks the fingers domain that binds the dna in other members of the x family, it binds dna tightly. to help interpret details of this interaction, molecular dynamics simulations of free pol x at different salt con ... | 2006 | 16214865 |
| development of a nested pcr and its internal control for the detection of african swine fever virus (asfv) in ornithodoros erraticus. | a nested pcr assay, with an internal control, was developed to detect african swine fever virus (asfv) dna in ornithodoros erraticus. the assay revealed a better analytical sensitivity than virus isolation and the oie pcr protocol. all ticks collected from the field, which were positive by virus isolation, were also positive by pcr. viral dna was detected in a further 19 out of 60 ticks from which no virus was isolated. our results show that this assay is reliable and can easily be used to scree ... | 2006 | 16328146 |
| dna polymerase x from african swine fever virus: quantitative analysis of the enzyme-ssdna interactions and the functional structure of the complex. | interactions of polymerase x from african swine fever virus with single-stranded dna (ssdna) have been studied, using quantitative fluorescence titration and analytical ultracentrifugation techniques. experiments were performed with a fluorescent etheno-derivative of ssdna oligomers. studies of unmodified ssdna oligomers were carried out using the competition titration method. the total site-size of the pol x-ssdna complex is 16(+/-1) nucleotide residues. the large total ssdna-binding site has a ... | 2006 | 16337650 |
| the viral protein a238l inhibits tnf-alpha expression through a cbp/p300 transcriptional coactivators pathway. | african swine fever virus (asfv) is able to inhibit tnf-alpha-induced gene expression through the synthesis of a238l protein. this was shown by the use of deletion mutants lacking the a238l gene from the vero cell-adapted ba71v asfv strain and from the virulent isolate e70. to further analyze the molecular mechanism by which the viral gene controls tnf-alpha, we have used jurkat cells stably transfected with the viral gene to identify the tnf-alpha regulatory elements involved in the induction o ... | 2006 | 16365438 |
| nuclear export of african swine fever virus p37 protein occurs through two distinct pathways and is mediated by three independent signals. | nucleocytoplasmic shuttling activity of the african swine fever virus p37 protein, a major structural protein of this highly complex virus, has been recently reported. the systematic characterization of the nuclear export ability of this protein constituted the major purpose of the present study. we report that both the n- and c-terminal regions of p37 protein are actively exported from the nucleus to the cytoplasm of yeast and mammalian cells. moreover, experiments using leptomycin b and small ... | 2006 | 16415017 |
| visualization of the african swine fever virus infection in living cells by incorporation into the virus particle of green fluorescent protein-p54 membrane protein chimera. | many stages of african swine fever virus infection have not yet been studied in detail. to track the behavior of african swine fever virus (asfv) in the infected cells in real time, we produced an infectious recombinant asfv (b54gfp-2) that expresses and incorporates into the virus particle a chimera of the p54 envelope protein fused to the enhanced green fluorescent protein (egfp). the incorporation of the fusion protein into the virus particle was confirmed immunologically and it was determine ... | 2006 | 16490226 |
| contributions of an endonuclease iv homologue to dna repair in the african swine fever virus. | we recently demonstrated that african swine fever virus dna polymerase x (pol x) is extremely error-prone during single-nucleotide gap-filling and that the downstream asfv dna ligase seals 3' mismatched nicks with high efficiency. to further assess the credence of our hypothesis that these proteins may promote viral diversification by functioning within the context of an aberrant dna repair pathway, herein we characterize the third protein expected to function in this system, a putative ap endon ... | 2006 | 16503634 |
| antigenic properties and diagnostic potential of african swine fever virus protein pp62 expressed in insect cells. | african swine fever (asf) is an infectious and economically important disease of domestic pigs. the absence of vaccine renders the diagnostic test the only tool that can be used for the control of new outbreaks of the disease. at present, the enzyme-linked immunosorbent assay (elisa) test is the most useful method for large-scale asf serological studies, although false positives have been detected, mainly on poorly preserved sera. in order to improve the current diagnostic test available for asf ... | 2006 | 16517882 |
| african swine fever virus pb119l protein is a flavin adenine dinucleotide-linked sulfhydryl oxidase. | protein pb119l of african swine fever virus belongs to the erv1p/alrp family of sulfhydryl oxidases and has been described as a late nonstructural protein required for correct virus assembly. to further our knowledge of the function of protein pb119l during the virus life cycle, we have investigated whether this protein possesses sulfhydryl oxidase activity, using a purified recombinant protein. we show that the purified protein contains bound flavin adenine dinucleotide and is capable of cataly ... | 2006 | 16537584 |
| african swine fever virus protein pe296r is a dna repair apurinic/apyrimidinic endonuclease required for virus growth in swine macrophages. | we show here that the african swine fever virus (asfv) protein pe296r, predicted to be a class ii apurinic/apyrimidinic (ap) endonuclease, possesses endonucleolytic activity specific for ap sites. biochemical characterization of the purified recombinant enzyme indicated that the k(m) and catalytic efficiency values for the endonucleolytic reaction are in the range of those reported for escherichia coli endonuclease iv (endo iv) and human ape1. in addition to endonuclease activity, the asfv enzym ... | 2006 | 16641276 |
| kinetics of african swine fever virus infection in ornithodoros erraticus ticks. | the kinetics of african swine fever virus (asfv) infection in ornithodoros erraticus ticks were investigated in specimens collected in the field at different times following an outbreak of the disease in portugal in 1999 and in ticks infected experimentally with a virus isolated from a tick collected during this outbreak. in ticks collected from the field, initial screening for asfv was carried out by pcr, followed by attempts to isolate the virus in macrophage cultures. considering total number ... | 2006 | 16760388 |
| molecular epidemiology of african swine fever virus studied by analysis of four variable genome regions. | variable regions of the african swine fever virus genome, which contain arrays of tandem repeats, were compared in the genomes of isolates obtained over a 40-year period. comparison of the size of products generated by polymerase chain reaction (pcr) from four different genome regions, within the b602l and kp86r genes and intergenic regions j286l and btsj, placed 43 closely related isolated from europe, the caribbean, west and central africa into 17 different virus sub-groups. sequence analysis ... | 2006 | 16817033 |
| molecular diagnosis and epidemiology of african swine fever outbreaks in tanzania. | 2006 | 16838208 | |
| african swine fever virus induces filopodia-like projections at the plasma membrane. | when exiting the cell vaccinia virus induces actin polymerization and formation of a characteristic actin tail on the cytosolic face of the plasma membrane, directly beneath the extracellular particle. the actin tail acts to propel the virus away from the cell surface to enhance its cell-to-cell spread. we now demonstrate that african swine fever virus (asfv), a member of the asfarviridae family, also stimulates the polymerization of actin at the cell surface. intracellular asfv particles projec ... | 2006 | 16869831 |
| phenotype-based identification of host genes required for replication of african swine fever virus. | 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 fac ... | 2006 | 16912318 |
| optimization and validation of recombinant serological tests for african swine fever diagnosis based on detection of the p30 protein produced in trichoplusia ni larvae. | we describe the validation of an enzyme-linked immunosorbent assay (elisa) and confirmatory immunoblotting assays based on a recombinant p30 protein (p30r) produced in insect larvae using a baculovirus vector. such validation included the following: (i) the scaling up and standardization of p30r production and the associated immunoassays, (ii) a broad immunological analysis using a large number of samples (a total of 672) from spain and different african locations, and (iii) the detection of the ... | 2006 | 16954235 |
| african swine fever virus causes microtubule-dependent dispersal of the trans-golgi network and slows delivery of membrane protein to the plasma membrane. | viral interference with secretory cargo is a common mechanism for pathogen immune evasion. selective down regulation of critical immune system molecules such as major histocompatibility complex (mhc) proteins enables pathogens to mask themselves from their host. african swine fever virus (asfv) disrupts the trans-golgi network (tgn) by altering the localization of tgn46, an organelle marker for the distal secretory pathway. reorganization of membrane transport components may provide a mechanism ... | 2006 | 16956944 |
| generation of filamentous instead of icosahedral particles by repression of african swine fever virus structural protein pb438l. | the mechanisms involved in the construction of the icosahedral capsid of the african swine fever virus (asfv) particle are not well understood at present. capsid formation requires protein p72, the major capsid component, but other viral proteins are likely to play also a role in this process. we have examined the function of the asfv structural protein pb438l, encoded by gene b438l, in virus morphogenesis. we show that protein pb438l associates with membranes during the infection, behaving as a ... | 2006 | 17005638 |
| the african swine fever virus nonstructural protein pb602l is required for formation of the icosahedral capsid of the virus particle. | african swine fever virus (asfv) protein pb602l has been described as a molecular chaperone for the correct folding of the major capsid protein p72. we have studied the function of protein pb602l during the viral assembly process by using a recombinant asfv, vb602li, which inducibly expresses the gene coding for this protein. we show that protein pb602l is a late nonstructural protein, which, in contrast with protein p72, is excluded from the viral factory. repression of protein pb602l synthesis ... | 2006 | 17035321 |
| regulation of inducible nitric oxide synthase expression by viral a238l-mediated inhibition of p65/rela acetylation and p300 transactivation. | uncontrolled generation of nitric oxide (no) by inducible nitric-oxide synthase (inos) can cause damage to host cells and inflammation, two undesirable events for virus spreading. african swine fever virus (asfv) infection regulates inos-induced gene expression through the synthesis of the a238l virus protein. we here explored the role of a238l, an nf-kappab and nfat inhibitor, in the regulation of inos transcription in macrophages. no production and inos mrna and protein levels as well as inos ... | 2006 | 17041221 |
| macrophage transcriptional responses following in vitro infection with a highly virulent african swine fever virus isolate. | we used a porcine microarray containing 2,880 cdnas to investigate the response of macrophages to infection by a virulent african swine fever virus (asfv) isolate, malawi lil20/1. one hundred twenty-five targets were found to be significantly altered at either or both 4 h and 16 h postinfection compared with targets after mock infection. these targets were assigned into three groups according to their temporal expression profiles. eighty-six targets showed increased expression levels at 4 h post ... | 2006 | 17041222 |
| asfv dna polymerse x is extremely error-prone under diverse assay conditions and within multiple dna sequence contexts. | we previously demonstrated that the dna repair system encoded by the african swine fever virus (asfv) is both extremely error-prone during the single-nucleotide gap-filling step (catalyzed by asfv dna polymerase x) and extremely error-tolerant during the nick-sealing step (catalyzed by asfv dna ligase). on the basis of these findings we have suggested that at least some of the diversity known to exist among asfv isolates may be a consequence of mutagenic dna repair, wherein damaged nucleotides a ... | 2006 | 17144676 |
| reduced redox potential of the cytosol is important for african swine fever virus capsid assembly and maturation. | assembly of african swine fever virus (asfv) involves the transfer of the major capsid protein, p73, from the cytosol onto the cytoplasmic face of endoplasmic reticulum-derived membranes. during this process, the folding of p73 is dependent upon transient association with a specific viral chaperone, cap80. the cell cytoplasm maintains high concentrations of reduced glutathione, leading to a reducing environment. here, the effects of redox environment on the assembly of asfv have been studied. di ... | 2007 | 17170439 |
| genetic characterisation of african swine fever viruses from outbreaks in southern africa (1973-1999). | african swine fever (asf) is a highly lethal and economically significant disease of domestic pigs in the southern african sub-region, where outbreaks regularly occur. there is anecdotal evidence suggesting that trans-boundary movement of infected animals may have played a role in precipitating widespread outbreaks in the past, however, since the 1970s outbreaks have generally been more localised, particularly in those countries where control of animal movement is strictly regulated. the origin ... | 2007 | 17174485 |
| molecular beacon real-time pcr detection of swine viruses. | rapid and reliable detection of viral pathogens is critical for the management of the diseases threatening the economic competitiveness of the swine farming industry worldwide. molecular beacon assays are one type of real-time polymerase chain reaction (pcr) technology capable of fast, specific, sensitive, and reliable viral detection. in this paper, the development of molecular beacon assays as novel tools for the rapid detection of aujeszky's disease virus, african swine fever virus, porcine c ... | 2007 | 17196673 |
| the myd116 african swine fever virus homologue interacts with the catalytic subunit of protein phosphatase 1 and activates its phosphatase activity. | the dp71l protein of african swine fever virus (asfv) shares sequence similarity with the herpes simplex virus icp34.5 protein over a c-terminal domain. we showed that the catalytic subunit of protein phosphatase 1 (pp1) interacts specifically with the asfv dp71l protein in a yeast two-hybrid screen. the chimeric full-length dp71l protein, from asfv strain badajoz 71 (ba71v), fused to glutathione s-transferase (dp71l-gst) was expressed in escherichia coli and shown to bind specifically to the pp ... | 2007 | 17215279 |
| detection of african swine fever virus genomic dna in a nigerian red river hog (potamochoerus porcus). | 2007 | 17220525 | |
| african swine fever virus a238l inhibitor of nf-kappab and of calcineurin phosphatase is imported actively into the nucleus and exported by a crm1-mediated pathway. | this study examined nuclear and cytoplasmic shuttling of the african swine fever virus (asfv) a238l protein, which is an inhibitor of nf-kappab and of calcineurin phosphatase. the results showed that the protein was present in both the nucleus and the cytoplasm in asfv-infected cells and that the higher molecular mass 32 kda form of the a238l protein was the predominant nuclear form, which accumulated later in infection. in contrast, both the 28 and 32 kda forms of the a238l protein were present ... | 2007 | 17251557 |
| an immunohistochemical study of the tonsils in pigs with acute african swine fever virus infection. | an immunohistochemical study of the tonsils was carried out to gain further insight in the pathogenesis of acute african swine fever (asf). twenty-one pigs were inoculated by intramuscular route with a highly virulent isolate of asf virus and painlessly killed at 1-7dpi. viral antigen was highly distributed in the tonsil from 3 to 4dpi and an increase in the number of monocyte-macrophages was very evident at the same days post inoculation. this phenomenon was observed together with an increase o ... | 2007 | 17258254 |
| use of damaged dna and dntp substrates by the error-prone dna polymerase x from african swine fever virus. | the structural specificity that translesion dna polymerases often show for a particular class of lesions suggests that the predominant criterion of selection during their evolution has been the capacity for lesion tolerance and that the error-proneness they display when copying undamaged templates may simply be a byproduct of this adaptation. regardless of selection criteria/evolutionary history, at present both of these properties coexist in these enzymes, and both properties confer a fitness a ... | 2007 | 17335287 |
| a unified kinetic mechanism applicable to multiple dna polymerases. | after extensive studies spanning over half a century, there is little consensus on the kinetic mechanism of dna polymerases. using stopped-flow fluorescence assays for mammalian dna polymerase beta (pol beta), we have previously identified a fast fluorescence transition corresponding to conformational closing, and a slow fluorescence transition matching the rate of single-nucleotide incorporation. here, by varying ph and buffer viscosity, we have decoupled the rate of single-nucleotide incorpora ... | 2007 | 17419590 |
| african swine fever virus p37 structural protein is localized in nuclear foci containing the viral dna at early post-infection times. | the replication of african swine fever virus dna is initiated inside the nucleus of host cells, being followed by a longer cytoplasmic replication stage. in face of previous results demonstrating the nucleo-cytoplasmic shuttling activity of asfv p37 structural protein when considered isolated from the virus infection, we performed a systematic analysis of the subcellular localization of p37 protein in asfv-infected cells, aiming at identifying the role of the nuclear transport mediated by this p ... | 2007 | 17580096 |
| serum concentrations of c-reactive protein, serum amyloid a, and haptoglobin in pigs inoculated with african swine fever or classical swine fever viruses. | to determine serum concentrations of the selected acute-phase proteins (apps) haptoglobin, serum amyloid a (saa), and c-reactive protein (crp) in pigs experimentally inoculated with classical swine fever (csf) and african swine fever (asf) viruses. | 2007 | 17605613 |
| intra-genotypic resolution of african swine fever viruses from an east african domestic pig cycle: a combined p72-cvr approach. | two of the 22 presently recognised african swine fever (asf) virus p72 genotypes are genetically homogeneous and are associated with domestic pig cycles. of these, genotype viii comprises just two p72 variants, designated 'a' and 'b' in this study, and is confined to four east african countries where it has caused numerous outbreaks between 1961 and 2001. in order to resolve relationships within this homogeneous genotype, the central variable region (cvr) of the 9rl open reading frame of 38 viru ... | 2007 | 17674176 |
| systematic analysis of longitudinal serological responses of pigs infected experimentally with african swine fever virus. | the protective immune response to african swine fever virus (asfv) includes both cellular and serological components. in this study, the role of antibodies in the pathogenicity and diagnosis of african swine fever (asf) was explored. accordingly, total and ig isotype antibody responses against the 12 viral proteins previously demonstrated to be the main targets of serological immunity were evaluated in longitudinally collected sera from pigs infected experimentally with the non-pathogenic asfv/n ... | 2007 | 17698651 |
| long-term storage at tropical temperature of dried-blood filter papers for detection and genotyping of rna and dna viruses by direct pcr. | in tropical countries the diagnosis of viral infections of humans or animals is often hampered by the lack of suitable clinical material and the necessity to maintain a cold chain for sample preservation up to the laboratory. this study describes the use of filter papers for rapid sample collection, and the molecular detection and genotyping of viruses when stored over long periods at elevated temperatures. infected blood was collected on filter papers, dried and stored at different temperatures ... | 2007 | 17714797 |
| interactions of the dna polymerase x of african swine fever virus with double-stranded dna. functional structure of the complex. | interactions of the polymerase x of african swine fever virus with the double-stranded dna (dsdna) have been studied with fluorescent dsdna oligomers, using quantitative fluorescence titrations, analytical ultracentrifugation, and fluorescence energy transfer techniques. studies with unmodified dsdnas were performed, using competition titration method. asv pol x binds the dsdna with a site-size of n=10(+/-2) base-pairs, which is significantly shorter than the total site-size of 16(+/-2) nucleoti ... | 2007 | 17765921 |
| african swine fever in mozambique: review, risk factors and considerations for control. | african swine fever (asf) is the most important disease that constrains pig production in mozambique. until 1994 it was apparently restricted to the central and northern provinces, but since 1994 outbreaks have been experienced throughout the country. asf causes severe economic losses both in the small commercial sector and among the large numbers of small-scale producers in the family sector in rural and peri-urban areas. the history of asf in mozambique since its first confirmation in 1960 is ... | 2007 | 17883201 |
| interactions of the dna polymerase x from african swine fever virus with gapped dna substrates. quantitative analysis of functional structures of the formed complexes. | energetics and specificity of interactions between the african swine fever virus polymerase x and gapped dna substrates have been studied, using the quantitative fluorescence titration technique. stoichiometries of pol x complexes, with the dna substrates, are higher than suggested by nmr studies. this can be understood in the context of the functionally heterogeneous organization of the total dna-binding site of pol x, which is composed of two dna-binding subsites. the enzyme forms two differen ... | 2007 | 17941646 |