Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| porcine endogenous retroviruses perv-a and perv-b infect neither mouse cells in vitro nor scid mice in vivo. | porcine endogenous retroviruses (pervs) pose a risk for xenotransplantations using pig materials as they are present in the genome of all pigs and are able to infect human cells in vitro. until recently, transmission of pervs in vivo was only described in severe combined immunodeficient (scid) and nude mice inoculated with perv-producing cells. however, in this series of experiments microchimerism could not be excluded. to overcome this problem, the risk of perv infection was addressed in a simi ... | 2005 | 15812191 |
| lack of cross-species transmission of porcine endogenous retrovirus in pig-to-baboon xenotransplantation with sustained depletion of anti-alphagal antibodies. | nonhuman primates are potential permissive animals for studying the risk of in vivo infection with porcine endogenous retrovirus (perv). anti-alphagal natural antibodies are considered one of the barriers for preventing perv infection, and it has been postulated that reduction of these antibodies could increase the risk of this infection. the aim of this study was to investigate the role of gas 914, which depletes anti-alphagal antibodies, in the potential in vivo transfer of perv after pig-to-b ... | 2005 | 15818319 |
| neutralising antibodies against the transmembrane protein of feline leukaemia virus (felv). | neutralising antibodies specific for feline leukaemia virus (felv) were induced by immunisation with recombinant felv transmembrane envelope protein p15e. epitope mapping revealed two epitopes located in similar regions to those previously identified for the porcine endogenous retrovirus (perv). one of the epitopes has partial homology and both are located in regions corresponding to epitopes recognised by neutralising antibodies in patients infected with hiv-1. | 2005 | 15837241 |
| characterization of a hollow fiber bioartificial liver device. | a three-compartment bioartificial liver (bal) has been developed for potential treatment of fulminant hepatic failure. it has been shown previously that viability and liver-specific functions were maintained in laboratory-scale bioreactors of such design. in this study, the performance of hepatocytes in a clinical-scale bioartificial liver was verified by sustained specific production rates of albumin and urea, along with oxygen consumption rates for up to 56 h and liver-specific gene expression ... | 2005 | 15854219 |
| [construction and evaluation of the property of decellular porcine aortic valve]. | to construct decellular porcine aortic valve (pav) and to observe the existence of porcine endogenous retrovirus (perv) and valve scaffold structure before and after implantation. | 2005 | 15854509 |
| prevention of perv infections in pig to human xenotransplantation by the rna interference silences gene. | the possibility of preventing the transmission of porcine endogenous retrovirus (perv) to human cells using short interfering rnas (sirna) was investigated. the sirna for the p30 of perv gag region was cloned into psuper, the polymerase-iii h1-rna gene promoter. a green fluorescence protein (gfp) was also cloned into psuper to establish psxgh. pig endothelial cells (pec) were transduced with the lacz gene by pseudotype infection, and infected with perv subtype b, resulting in the formation of pe ... | 2005 | 15858174 |
| analysis of pig-to-human porcine endogenous retrovirus transmission in a triple-species kidney xenotransplantation model. | clinical pig-to-human xenotransplantation might be associated with the risk of transmission of xenozoonoses, especially porcine endogenous retroviruses (pervs). we have established a pig-to-humanised-cynomolgus monkey xenotransplantation model allowing the analysis of potential perv-transmission from normal or transgenic porcine organs to human vascular tissue. pig-to-human kidney xenotransplantation was performed in cynomolgus monkeys. an interposition graft constructed from a human saphena vei ... | 2005 | 15864489 |
| cell-binding properties of the envelope proteins of porcine endogenous retroviruses. | to examine the binding properties of the envelope glycoproteins of porcine endogenous retrovirus subgroups a and b (perv-a and perv-b), we produced two forms of soluble envelope proteins, termed env-st and env-su, using a baculovirus expression system. env-st and env-su encompass one-third of the n-terminal and the entire surface unit (su) of the envelope protein, respectively. using these proteins, binding assays were performed in various mammalian cell lines. the binding properties of the env- ... | 2005 | 15876545 |
| no evidence of in vitro and in vivo porcine endogenous retrovirus infection after plasmapheresis through the amc-bioartificial liver. | currently a number of bioartificial livers (bal) based on porcine liver cells have been developed as a treatment to bridge acute liver failure patients to orthotopic liver transplantation or liver regeneration. these xenotransplantation related treatments hold the risk of infection of treated patients by porcine endogenous retrovirus (perv) released from the porcine cells, as in vitro infection experiments and transplantations in immunocompromised mice have shown that perv is able to infect huma ... | 2005 | 15943777 |
| porcine endogenous retrovirus encodes xenoantigens involved in porcine cellular xenograft rejection by mice. | identification of the antigens that stimulate transplant rejection can help develop graft-specific antirejection strategies. the xenoantigens recognized during rejection of porcine cellular xenografts have not been clearly defined, but it has been assumed that major histocompatibility complex (mhc) xenoantigens are involved. | 2005 | 15973168 |
| pseudotyping of porcine endogenous retrovirus by xenotropic murine leukemia virus in a pig islet xenotransplantation model. | the potential of porcine endogenous retrovirus (perv) as a human pathogen, particularly as a public health risk, is a major concern for xenotransplantation. in vitroperv transmission to human cells is well established. evidence from human/pig hematopoietic chimeras in immunodeficient mice suggests perv transmission from pig to human cells in vivo. however, recently yang et al. demonstrated in such a model that perv-c, a nonhuman-tropic class, could be transmitted via pseudotyping by xenotropic m ... | 2005 | 15996230 |
| [preliminary study on human embryonic kidney cell line hek-293 after porcine endogenous retrovirus infection]. | to assess the infectivity of porcine endogenous retrovirus (perv) via in vitro infection of human embryonic kidney cell line hek-293. | 2005 | 16091176 |
| prevalence of porcine endogenous retrovirus in chinese pig breeds and in patients treated with a porcine liver cell-based bioreactor. | to determine the prevalence of porcine endogenous retrovirus (perv) in various pig breeds raised in china including chinese experimental mini-pigs by perv-reverse transcriptase (perv-rt enzyme). moreover, the potential for infection of perv was investigated in patients treated with a bioreactor based on porcine liver cells (n = 3). | 2005 | 16094718 |
| the ethics debate in relation to xenotransplantation. | xenotransplantation is the transplantation of organs and cells from one species to another: it has enormous potential to increase the supply of organs and tissues to alleviate human disease. recent scientific progress has eliminated the obstacle of hyperacute rejection, which is the massive destruction of the transplanted organ within 24 h. despite this progress and the tremendous clinical potential, a number of ethical issues require careful consideration. these issues involve the human recipie ... | 2005 | 16110900 |
| xenotransplantation of porcine neonatal islets of langerhans and sertoli cells: a 4-year study. | porcine islets of langerhans for xenotransplantation into humans have been proposed as a solution to the shortage of human donors. rejection is one of the main constraints. this study presents the results of a clinical trial using a novel method for transplanting and immunoprotecting porcine islets in type 1 diabetic patients. | 2005 | 16131605 |
| an69 hollow fiber membrane will reduce but not abolish the risk of transmission of porcine endogenous retroviruses. | as the risk of porcine endogenous retrovirus (perv) infection is a major obstacle to the xenotransplantation of porcine tissue, we investigated whether an an69 hollow fibre membrane, used for islets of langerhans transplantation, could prevent the transfer of pervs and thus reduce the risk of perv infection. pk15 cells were used as a perv source. a specific and highly sensitive rcr was used for detection of a perv provirus dna (gag region) and a porcine mtdna. human u293 cells were incubated in ... | 2005 | 28849982 |
| porcine endogenous retrovirus transmission characteristics of galactose alpha1-3 galactose-deficient pig cells. | galactose alpha1-3 galactose (gal) trisaccharides are present on the surface of wild-type pig cells, as well as on viruses particles produced from such cells. the recognition of gal sugars by natural anti-gal antibodies (nab) in human and old world primate serum can cause the lysis of the particles via complement-dependent mechanisms and has therefore been proposed as an important antiviral mechanism. recently, pigs have been generated that possess disrupted galactosyl-transferase (ggta1) genes. ... | 2004 | 15140978 |
| reduced sensitivity to human serum inactivation of enveloped viruses produced by pig cells transgenic for human cd55 or deficient for the galactosyl-alpha(1-3) galactosyl epitope. | complement activation mediated by the major xenogeneic epitope in the pig, galactosyl-alpha(1-3) galactosyl sugar structure (alpha-gal), and human natural antibodies could cause hyperacute rejection (har) in pig-to-human xenotransplantation. the same reaction on viruses bearing alpha-gal may serve as a barrier to zoonotic infection. expressing human complement regulatory proteins or knocking out alpha-gal epitopes in pig in order to overcome har may therefore pose an increased risk in xenotransp ... | 2004 | 15140979 |
| establishing the reactivity of monoclonal antibodies against porcine endogenous retrovirus envelope protein. | xenotransplantation of pig organs may be associated with a risk of transmission of microorganisms. porcine endogenous retroviruses (perv) are of particular concern since in vitro experiments have demonstrated that human cells are susceptible to such microorganisms. to monitor the transmission of perv, highly sensitive and specific immunoassays must be developed for clinical surveillance. this report describes the production, preliminary characterization and application of a monoclonal antibody ( ... | 2004 | 15192273 |
| xenografts are an achievable breakthrough. | the objective of this communication is to show that pig-to-human organ transplantation could be feasible through genetic engineering. by introducing into donor pigs several different tolerance promoting genetic modifications there can be a synergistic effect to produce extended tolerance for xenografted organs in human recipients. nuclear-transfer cloning allows production of pigs with knockout mutations in the galactose-alpha-1,3-galactosyl transferase gene, in principle eliminating hyperacute ... | 2004 | 15193356 |
| porcine endogenous retroviral nucleic acid in peripheral tissues is associated with migration of porcine cells post islet transplant. | porcine islets represent an alternative source of insulin-producing tissue, however, porcine endogenous retrovirus (perv) remains a concern. in this study, scid mice were transplanted with nonencapsulated (non-ec), microencapsulated (ec) or macroencapsulated (in a theracyte trade mark device) neonatal porcine islets (npis), and peripheral tissues were screened for presence of viral dna and mrna. to understand the role of an intact immune system in perv incidence, mice with established npi grafts ... | 2004 | 15196061 |
| no transmission of porcine endogenous retrovirus after transplantation of adult porcine islets into diabetic nude mice and immunosuppressed rats. | the aim of this study was to investigate whether transmission of porcine endogenous retrovirus (perv) occurs in a model of diabetes reversal by the xenotransplantation of adult porcine islets (apis) into immunoincompetent diabetic rodents. | 2004 | 15196128 |
| porcine cell microchimerism but lack of productive porcine endogenous retrovirus (perv) infection in naive and humanized scid-beige mice treated with porcine peripheral blood mononuclear cells. | pigs are considered a suitable source of cells and organs for xenotransplantation. all known strains of pigs contain porcine endogenous retrovirus (perv) and perv released by porcine cells may infect human cells in vitro and severe-combined immunodeficient (scid) mice in vivo. humanized scid (hu-scid) mice develop immune response to porcine antigens. here we investigated perv transmission in humanized scid-beige mice using porcine peripheral blood mononuclear cells (pbmc) as the donor tissue (an ... | 2004 | 15203124 |
| human immune responses to porcine endogenous retrovirus-derived peptides presented naturally in the context of porcine and human major histocompatibility complex class i molecules: implications in xenotransplantation of porcine organs. | porcine endogenous retroviruses (perv) have been shown to infect human cells, raising concerns regarding safety of xenotransplantation. in patients exposed to porcine tissues, no perv infection has been observed. this study was designed to develop human cd8+ cytotoxic t lymphocytes (ctl) against perv-derived peptides presented in the context of human leukocyte antigen (hla) or swine leukocyte antigen (sla) class i molecules and to define dominant epitopes contributed by perv. | 2004 | 15239626 |
| porcine endogenous retroviruses infect cells lacking cognate receptors by an alternative pathway: implications for retrovirus evolution and xenotransplantation. | a phq motif near the amino termini of gammaretroviral envelope glycoprotein surface (su) subunits is important for infectivity but not for incorporation into virions or binding to cognate receptors. the h residue of this motif is most critical, with all substitutions we tested being inactive. interestingly, porcine endogenous retroviruses (pervs) of all three host-range groups, a, b, and c, lack full phq motifs, but most members have an h residue at position 10. h10a perv mutants are noninfectio ... | 2004 | 15280495 |
| identification of a neutralizing epitope in the betae-betaf loop of vp1 of equine rhinitis a virus, defined by a neutralization-resistant variant. | equine rhinitis a virus strain 393/76 (erav.393/76) was passaged in the presence of post-infection erav.393/76 equine polyclonal antiserum (epa). viruses with increased resistance to neutralization by epa were obtained after 15 passages. compared with the parent virus, five plaque-purified, neutralization-resistant mutant viruses, in addition to the non-plaque-purified viruses that were examined, had a glu-->lys change at position 658, which is located in the predicted betae-betaf (ef) loop of v ... | 2004 | 15302948 |
| xenotransplantation: infectious risk revisited. | xenotransplantation is a possible solution for the shortage of tissues for human transplantation. multiple hurdles exist to clinical xenotransplantation, including immunologic barriers, metabolic differences between pigs--the source species most commonly considered--and humans, and ethical concerns. since clinical trials were first proposed almost 10 years ago, the degree of risk for infection transmitted from the xenograft donor to the recipient has been extensively investigated. a number of po ... | 2004 | 15307825 |
| mouse retrovirus mediates porcine endogenous retrovirus transmission into human cells in long-term human-porcine chimeric mice. | porcine endogenous retrovirus (perv) is a potential pathogen in clinical xenotransplantation; transmission of perv in vivo has been suggested in murine xenotransplantation models. we analyzed the transmission of perv to human cells in vivo using a model in which immunodeficient nod/scid transgenic mice were transplanted with porcine and human lymphohematopoietic tissues. our results demonstrate, we believe for the first time, that human and pig cells can coexist long-term (up to 25 weeks) withou ... | 2004 | 15343388 |
| phylogenetic relationship of porcine endogenous retrovirus (perv) in chinese pigs with some type c retroviruses. | pcr amplification of proviral dna extracted from peripheral blood lymphocytes of three chinese pigs (banna minipig inbreed (bmi), wu-zhi-shan pig (wzsp) and neijiang pig (njp)), using primers corresponding to highly conserved regions of reverse transcriptase (rt) of pol gene and nucleocapsid sequence of gag gene. pcr products were then extracted and cloned into pgem-t vector. phylogenetic analysis of the nucleotide sequences of perv-bmi, perv-wzsp and perv-wzsp revealed that they were of retrovi ... | 2004 | 15351490 |
| [studies on the infectivity by porcine endogenous retrovirus with porcine skin fibroblast in vitro and in vivo]. | to understand the infectivity by porcine endogenous retrovirus with porcine skin fibroblast cell in vitro and in vivo, porcine skin fibroblast cell established by our laboratory were co-cultured with neo/hek293 cell for the infection of perv in vitro, and were subcutaneously transplantated to scid (severe combined immuno-deficiency) mice for the infection of perv in vivo, laying the foundation for valuation of biologic safety of xenotransplantation. the event of neo/hek293 cells infected by perv ... | 2004 | 15481536 |
| screening and analysis of porcine endogenous retrovirus in chinese banna minipig inbred line. | pigs have been the most likely animal as the source of cells, tissues, and organs for xenotransplantation. but the use of pigs in xenotransplantation is associated with the risk of porcine endogenous retrovirus (perv) transmission. previous studies have identified that the proviruses are integrated into the genome of normal pigs and that virus particles released from the porcine cells can infect human cells in vitro. as a unique inbred pig, banna minipig inbred (bmi) has a huge potential value f ... | 2004 | 15561290 |
| phylogenetic analysis of porcine endogenous retrovirus variation in three chinese pigs. | pcr amplification was performed on genomic dna extracted from peripheral blood lymphocytes of three species of chinese pigs (banna minipig inbreed [bmi], wu-zhi-shan pig [wzsp], and nei jiang pig [njp]), using primers corresponding to the highly conserved regions of polymerase (pol) gene. extracted pcr products were then cloned in a pgem-t vector. phylogenetic analysis of the nucleotide sequences of bmi-perv, njjp-perv, and wzsp-perv revealed them to be a novel category of perv. in comparison to ... | 2004 | 15561294 |
| determinants of high titer in recombinant porcine endogenous retroviruses. | porcine endogenous retroviruses (pervs) pose a potential stumbling block for therapeutic xenotransplantation, with the greatest threat coming from viruses generated by recombination between members of the perv subgroup a (perv-a) and perv-c families (perv-a/c recombinants). perv-a and perv-b have been shown to infect human cells in culture, albeit with low titers. perv-c has a more restricted host range and cannot infect human cells. a recombinant perv-a/c virus (perv-a14/220) contains the perv- ... | 2004 | 15564495 |
| evidence and consequence of porcine endogenous retrovirus recombination. | the genetic nature and biological effects of recombination between porcine endogenous retroviruses (perv) were studied. an infectious molecular clone was generated from a high-titer, human-tropic perv isolate, perv-a 14/220 (b. a. oldmixon, et al. j. virol. 76:3045-3048, 2002; t. a. ericsson et al. proc. natl. acad. sci. usa 100:6759-6764, 2003). to analyze this sequence and 15 available full-length perv nucleotide sequences, we developed a sequence comparison program, loha(tm) to calculate loca ... | 2004 | 15564496 |
| the screening and identification of endogenous retrovirus free cemps. | the provirus dna sequence of porcine endogenous retrovirus (perv) distributed in the pig genome is the major obstacle that restricts the swine as the organ donors in xenotransplantation, and the copy number of perv varies greatly among different breeds and individuals. in the experiment, 67 healthy, female chinese experimental mini-pigs (cemps) aged at 3-6 months were selected from the animal husbandry station of china agricultural university, the copy number of perv and types of envelope protei ... | 2004 | 15620113 |
| [analysis of presence and difference of sequence of porcine endogenous retrovirus in dna genomes from peripheral blood white cells of pig and mrna in tissues from mini-pigs]. | the aim is to investigate biological features of porcine endogenous retrovirus (perv) of pigs in china and to provide basic parameters for evaluation of biological safety of xenotransplantation from pig to human. in this study, basic biologic features of perv of dna of peripheral blood white cells of 12 species of domestic pigs in china were examined by polymerase chain reaction; analysis of difference of perv gene sequence was investigated by sliver-stained single stranded conformational polymo ... | 2004 | 15636362 |
| limited infection without evidence of replication by porcine endogenous retrovirus in guinea pigs. | porcine endogenous retrovirus (perv) may potentially be transmitted through porcine xenotransplantation products administered to humans. this study examined the feasibility of using guinea pigs as a model to characterize the in vivo infectivity of perv. to enhance the susceptibility of guinea pigs to retroviral infection or genomic integration, moderate physiological or immunological changes were induced prior to exposing the animals to perv. quantitative perv-specific pcr performed on all teste ... | 2004 | 14718614 |
| identification of exogenous forms of human-tropic porcine endogenous retrovirus in miniature swine. | the replication of porcine endogenous retrovirus subgroup a (perv-a) and perv-b in certain human cell lines indicates that perv may pose an infectious risk in clinical xenotransplantation. we have previously reported that human-tropic pervs isolated from infected human cells following cocultivation with miniature swine peripheral blood mononuclear cells (pbmc) are recombinants of perv-a with perv-c. here, we report that these recombinants are exogenous viruses in miniature swine; i.e., they are ... | 2004 | 14963150 |
| guided tissue regeneration: porcine matrix does not transmit perv. | for cardiovascular tissue engineering, acellularized scaffolds of porcine matrices have been successfully used. however, the possibility of porcine endogenous retrovirus (perv) transmission remains debatable. in this study, we investigated whether acellularized porcine vascular scaffolds cause cross-species transmission of perv in a xenogenic model. | 2004 | 15020135 |
| prevalence of porcine endogenous retrovirus in domestic pigs in japan and its potential infection in dogs xenotransplanted with porcine pancreatic islet cells. | the prevalence of porcine endogenous retrovirus (perv) proviral dna among various pig breeds raised in japan was investigated by polymerase chain reaction (pcr). moreover, potential infection of perv was investigated by pcr and reverse transcriptase-polymerase chain reaction (rt-pcr) in experimentally induced diabetic dogs (n=5) implanted with the diffusion chamber type bio-artificial endocrine pancreas (bio-aep) containing porcine pancreatic endocrine (pe) cells. no immunosuppressant was used a ... | 2004 | 15031539 |
| genotyping of porcine endogenous retroviruses from a family of miniature swine. | the identification of animals in an inbred miniature swine herd that consistently fail to produce replication- competent humantropic porcine endogenous retrovirus (perv) has prompted studies on the biology of perv in transmitter and nontransmitter animals. we analyzed perv rna transcript profiles in a family of inbred miniature swine (sla(d/d) haplotype) in which individual members differed in their capacity to generate humantropic and ecotropic (i.e., pigtropic) virus. we identified unique haei ... | 2004 | 14671113 |
| hybrid bioartificial liver: establishing a reversibly immortalized human hepatocyte line and developing a bioartificial liver for practical use. | recently, much attention has been attracted by a novel therapy for liver failure using a hybrid bioartificial liver (bal) support device that incorporates living liver cells. researchers in various fields have considered the following cells for potential use in bals: human embryonic stem (es) cells; somatic stem cells; differentiated tissue cells; and cells derived from tissues of different animal species, particularly from the pig. with their pluripotency, human es cells are extremely useful, a ... | 2003 | 14691665 |
| sensitivity to human serum of gammaretroviruses produced from pig endothelial cells transduced with glycosyltransferase genes. | reduction of pig cell-surface alpha-galactosyl (gal) epitope, galalpha1, 3galbeta1, 4glcnac-r, by the introduction of glycosyltransferase genes is effective in suppressing hyperacute rejection (har) in pig-to-human xenotransplantation. the transmission of porcine endogenous retroviruses (pervs) has been recognized as a potential risk factor associated with xenotransplantation. in this study, effects of the introduction of glycosyltransferase genes to pig cells on the sensitivity of gammaretrovir ... | 2003 | 14708522 |
| [the quantity analysis of reverse transcriptase in porcine endogenous retrovirus expressed in banna minipig inbred]. | quantitative rt(reverse transcriptase) assay was established to detect the reverse transcriptase in plasma of thirty-four chinese banna minipig inbred in this work. the protocol was given in the rt kit (roche), using hiv-1 as the positive control of the kit and supernatant of pk-15 as the perv positive control respectively. the results show that positive reverse transcriptase reaction can be detected in the plasma of the pigs, but the levels are much lower than that of hiv-1 and lower than that ... | 2003 | 14716853 |
| sequence analysis of porcine endogenous retrovirus long terminal repeats and identification of transcriptional regulatory regions. | porcine cells express endogenous retroviruses, some of which are infectious for human cells. to better understand the replication of these porcine endogenous retroviruses (pervs) in cells of different types and animal species, we have performed studies of the long terminal repeat (ltr) region of known gammaretroviral isolates of perv. nucleotide sequence determination of the ltrs of perv-nih, perv-c, perv-a, and perv-b revealed that the perv-a and perv-b ltrs are identical, whereas the perv-nih ... | 2003 | 12477819 |
| differences in release and determination of subtype of porcine endogenous retroviruses produced by stimulated normal pig blood cells. | porcine endogenous retroviruses (pervs) are of particular concern with xenotransplantations using pig cells, tissues or organs as they are present in the genome of all pig strains and are able to infect human cells in vitro. however, it remains unclear whether perv particles will be produced in vivo and whether they may infect xenotransplant recipients. since normal pig peripheral blood mononuclear cells (pbmcs) may be transmitted together with the transplanted organ, the production of pervs by ... | 2003 | 12566695 |
| a primary screening of porcine endogenous retrovirus in some chinese pigs. | 2003 | 12591523 | |
| porcine endogenous retroviruses (pervs) and xenotransplantation: screening for transmission in several clinical trials and in experimental models using non-human primates. | xenotransplantation may develop into a medical technology able to save or improve the quality of life. porcine endogenous retroviruses (pervs), because they are integrated in the genome of all pig strains, because they are produced by normal pig cells, and because they can infect human cell in vitro, are considered to be the main microbiological risk if pig cells, tissues or organs are to be transplanted. indeed, serial passaging of perv on human cells, simulating the situation during xenotransp ... | 2003 | 15114938 |
| expression and characterization of a recombinant novel reverse transcriptase of a porcine endogenous retrovirus. | the study of porcine endogenous retroviruses (pervs) becomes increasingly important due to the potential use of pig cells, tissues, and organs as a source for xenogenic cell therapy and xenotransplantation into humans. consequently, we have constructed a plasmid that induces in bacteria the synthesis of a soluble and highly active reverse transcriptase (rt) of perv-b. the purified perv rt was studied biochemically in comparison with the rt of murine leukemia virus (mlv), because of the high-sequ ... | 2003 | 12667803 |
| neutralizing antibodies against conserved domains of p15e of porcine endogenous retroviruses: basis for a vaccine for xenotransplantation? | porcine xenotransplants may offer a potential solution to the problem posed by the limited supply of allotransplants. however, xenotransplantation may be associated with the risk of transmission of microorganisms, in particular of porcine endogenous retroviruses (pervs) that are an integral part of the porcine genome and able to infect human cells in vitro. possible strategies to prevent virus transmission include the development of perv knockout animals or of effective vaccines. when antisera p ... | 2003 | 12667808 |
| ultra-sensitive and specific detection of porcine endogenous retrovirus (perv) using a sequence-capture real-time pcr approach. | use of porcine xenografts presents as a possible solution to the current shortage of human allografts limiting transplantation procedures. while no definitive observation of in vivo porcine endogenous retrovirus (perv) transmission in humans has been reported, the in vitro ability of perv to infect human cells and the observation of perv transmission to immunodeficient mice suggest a need for ultra-sensitive techniques to monitor porcine xenograft recipients and contacts for possible perv transm ... | 2003 | 12711065 |
| identification of receptors for pig endogenous retrovirus. | xenotransplantation of porcine tissues has the potential to treat a wide variety of major health problems including organ failure and diabetes. balanced against the potential benefits of xenotransplantation, however, is the risk of human infection with a porcine microorganism. in particular, the transmission of porcine endogenous retrovirus (perv) is a major concern [chapman, l. e. & bloom, e. t. (2001) j. am. med. assoc. 285, 2304-2306]. here we report the identification of two, sequence-relate ... | 2003 | 12740431 |
| detection of porcine endogenous retrovirus in cultures of freshly isolated porcine bone marrow cells. | pigs are under consideration as possible sources of organs for xenotransplantation in humans. the induction of hematopoietic microchimerism through xenotransplantation of source animal hematopoietic cells has been suggested as a means to induce tolerance in potential recipients. because all porcine cells contain genetic information for porcine endogenous retrovirus (perv), coculture techniques, reverse transcriptase (rt) and reverse transcriptase-polymerase chain reaction assays were used to det ... | 2003 | 12795682 |
| inactivation of porcine endogenous retrovirus by human serum as a function of complement activated through the classical pathway. | background: the clinical use of organs and cells of pig donors as a source of tissue for xenotransplantation and extracorporeal therapies has been problematic due to the risk for zoonotic infection of porcine endogenous retroviruses (perv). methods: the effect of human serum on perv was evaluated using an infectivity assay and virolysis assay. cell-free perv infection to human 293 cells was determined by the presence of proviruses 5 days post-infection by a highly sensitive nested pcr, and the l ... | 2003 | 12809937 |
| xenoreactive anti-galalpha(1,3)gal antibodies prevent porcine endogenous retrovirus infection of human in vivo. | the discovery of porcine endogenous retroviruses (perv) has raised concerns regarding the safety of pig to human xenotransplantation. in this study, we examined perv infection of human cells in vivo. furthermore, we examined the effect of human xenoreactive natural antibody on in vivo perv infection. human peripheral blood leukocyte reconstituted severe combined immunodeficiency mice were transplanted with porcine aortic endothelial cells (paec). perv gene expression was readily detected in huma ... | 2003 | 12826373 |
| characterization of two porcine endogenous retrovirus integration loci and variability in pigs. | the pig (sus scrofa) is a potential organ donor for man but porcine endogenous retroviruses (pervs) represent an important concern for patients, and identification or engineering of perv-free pigs suitable for xenotransplantation is a major undertaking. consequently, studies of variability in pigs for the presence of pervs at specific loci are a prerequisite. we identified genomic flanking sequences of two pervs cloned in bacterial artificial chromosomes, a replication-competent perv-a at locus ... | 2003 | 12827326 |
| detection of porcine endogenous retrovirus (perv) using highly specific antisera against gag and env. | porcine endogenous retroviruses (perv) are considered an obstacle to the safe use of cells, tissues, and organs from pigs in the course of xenotransplantation. thus, the detection of viral proteins and of a potential perv infection is of major interest. recently, we have published the generation of a highly specific antiserum directed against the nucleocapsid (p10) of perv (xenotransplantation 7 (2000), 221). here we present new peptide-antisera specific to the capsid protein (p30) and the surfa ... | 2003 | 12832219 |
| packaging of human endogenous retrovirus sequences is undetectable in porcine endogenous retrovirus particles produced from human cells. | the chronic shortage of human donor organs and tissues for allotransplantation could be relieved if clinical xenotransplantation were to become a viable clinical therapy. balanced against the benefits of xenotransplantation are the possible consequences of zoonotic infections, and in particular, infection by porcine endogenous retrovirus (perv). an often-proclaimed risk of perv infection is the possible recombination of perv with human endogenous retroviruses (herv). to address this issue, we ex ... | 2003 | 12919738 |
| xenotransplantation and pig endogenous retroviruses. | xenotransplantation, in particular transplantation of pig cells, tissues and organs into human patients, may alleviate the current shortage of suitable allografts available for human transplantation. this overview addresses the physiological, immunological and virological factors considered with regard to xenotransplantation. among the issues reviewed are the merits of using pigs as xenograft source species, the compatibility of pig and human organ physiology and the immunological hindrances wit ... | 2003 | 12931341 |
| [analysis of subtype of porcine endogenous retrovirus in two species of chinese pigs]. | to analyze the subtype of porcine endogenous retrovirus (perv) in two species of chinese pigs-wu zhishan pig and banna minipig inbred; the total number of pigs being eighty six. | 2003 | 12947687 |
| porcine endogenous retroviruses: no infection in patients treated with a bioreactor based on porcine liver cells. | acute liver failure (alf) remains a disease with high mortality. bioartificial liver support systems, which combine living cells of the liver in an extracorporeal circuit, have been successfully used in first clinical trials. the shortage of human organs to be used for bioreactors and the lack of safe and effective human liver cell lines have resulted in pigs becoming an important hepatic cell source. however, using these cells may be associated with the risk of transmission of porcine endogenou ... | 2003 | 12957184 |
| in vivo model for cross-species porcine endogenous retrovirus transmission using tissue engineered pulmonary arteries. | acellularised porcine scaffolds have been successfully used for cardiovascular tissue engineering. however, there is concern about the possibility of porcine endogenous retrovirus (perv) transmission. in this study we developed an in vivo model for cross-species perv transmission. | 2003 | 12965305 |
| genetic alterations of the long terminal repeat of an ecotropic porcine endogenous retrovirus during passage in human cells. | human-tropic porcine endogenous retroviruses (perv) such as perv-a and perv-b can infect human cells and are therefore a potential risk to recipients of xenotransplants. a similar risk is posed by recombinant viruses containing the receptor-binding site of perv-a and large parts of the genome of the ecotropic perv-c including its long terminal repeat (ltr). we describe here the unique organization of the perv-c ltr and its changes during serial passage of recombinant virus in human cells. an inc ... | 2003 | 14517066 |
| acellularized porcine heart valve scaffolds for heart valve tissue engineering and the risk of cross-species transmission of porcine endogenous retrovirus. | acellularized porcine heart valve scaffolds have been successfully used for heart valve tissue engineering, creating living functioning heart valve tissue. however, there is concern about the possibility of porcine endogenous retrovirus transmission. in this study we investigated whether acellularized porcine heart valve scaffold causes cross-species transmission of porcine endogenous retrovirus in a sheep model. | 2003 | 14566238 |
| bridging a patient with acute liver failure to liver transplantation by the amc-bioartificial liver. | recently a phase i clinical trial has been started in italy to bridge patients with acute liver failure (alf) to orthotopic liver transplantation (olt) by the amc-bioartificial liver (amc-bal). the amc-bal is charged with 10 x 10(9) viable primary porcine hepatocytes isolated from a specified pathogen-free (spf) pig. here we report a patient with alf due to acute hbv infection. this patient was treated for 35 h by two amc-bal treatments and was bridged to olt. there was improvement of biochemica ... | 2003 | 14579924 |
| intracellularly expressed single-domain antibody against p15 matrix protein prevents the production of porcine retroviruses. | the presence of porcine endogenous retroviruses presents a potential risk of transmission of infectious diseases (xenozoonosis) if tissues and organs from genetically modified pigs are to be used in xenotransplantation. here, we report that intracellular expression of a llama single-domain antibody against p15, the matrix domain protein of the porcine endogenous retrovirus gag polyprotein, blocks retrovirus production, providing the possibility of eliminating the risk of infection in xenotranspl ... | 2003 | 14581550 |
| relative age of proviral porcine endogenous retrovirus sequences in sus scrofa based on the molecular clock hypothesis. | porcine endogenous retroviruses (perv) are discussed as putative infectious agents in xenotransplantation. perv classes a, b, and c harbor different envelope proteins. two different types of long terminal repeat (ltr) structures exist, of which both are present only in perv-a. one type of ltr contains a distinct repeat structure in u3, while the other is repeatless, conferring a lower level of transcriptional activity. since the different ltr structures are distributed unequally among the provir ... | 2003 | 14581574 |
| some morphological, growth, and genomic properties of human cells chronically infected with porcine endogenous retrovirus (perv). | a major concern in using porcine organs for transplantation is the potential of transmission of porcine endogenous retrovirus (perv). to investigate the long-term effects of perv infection on human cells, human embryonic kidney cell line hek-293 infected with perv pk-15 was maintained for up to 72 passages and samples were harvested at intervals for use in morphological, growth, and genomic analyses. morphology, dna content/cell, and doubling time of uninfected and infected cells were similar. r ... | 2003 | 14608403 |
| human cd59 incorporation into porcine endogenous retrovirus particles: implications for the use of transgenic pigs for xenotransplantation. | transgenic pigs have been engineered to express human cd59 (hcd59) in order to suppress hyperacute rejection of xenotransplants in human recipients. in this study, porcine endogenous retrovirus (perv) was produced in a porcine cell line expressing hcd59 in order to examine the effect of this complement control protein on perv neutralization by human sera. hcd59 was found to be incorporated into perv particles produced from engineered st-iowa cells. perv incorporation of hcd59 resulted in a drama ... | 2002 | 11799196 |
| porcine endogenous retrovirus transmission characteristics of an inbred herd of miniature swine. | here we report the identification of inbred miniature swine that failed to produce human-tropic replication-competent porcine endogenous retroviruses (htrc pervs), using in vitro coculture assays. when htrc pervs were isolated from transmitting animals, all were recombinant viruses, with the receptor-binding domain of perv-a combining with perv-c-related sequences. | 2002 | 11861871 |
| clinical and laboratory evaluation of the safety of a bioartificial liver assist device for potential transmission of porcine endogenous retrovirus. | the potential risk of transmission of porcine endogenous retroviruses (perv) from xenogeneic donors into humans has been widely debated. because we were involved in a phase i/ii clinical trial using a bioartificial liver support system (blss), we proceeded to evaluate the biosafety of this device. | 2002 | 11884940 |
| productive infection of a mink cell line with porcine endogenous retroviruses (pervs) but lack of transmission to minks in vivo. | porcine endogenous retroviruses (pervs) are considered a special risk for xenotransplantation because they are an integral part of the porcine genome and are able to infect cells of numerous species including humans in vitro. among these cells, the mink lung epithelial cell line mv1lu could be productively infected with perv. provirus integration was detected by pcr, expression of viral proteins was shown by immunostaining and reverse transcriptase was detected in cell supernatants. perv produce ... | 2002 | 11890525 |
| development and perspectives of bioartificial liver support. | bioartificial liver support systems containing adsorbent devices, xenogeneic whole liver perfusion, and hybrid bioartificial liver are anticipated to be effective for the treatment of severe hepatic failure. at present, whole liver perfusion and the hybrid bioartificial liver are two mainstreams in the field of the bioartificial liver, but it is still unclear whether either of them has significant beneficial effects in hepatic failure patients. we developed a new system of xenogeneic direct hemo ... | 2002 | 11941991 |
| molecular and enzymatic characterization of the porcine endogenous retrovirus protease. | the protease of the porcine endogenous retrovirus (perv) subtypes a/b and c was recombinantly expressed in escherichia coli as proteolytically active enzyme and characterized. the perv gag precursor was also recombinantly produced and used as the substrate in an in vitro enzyme assay in parallel with synthetic nonapeptide substrates designed according to cleavage site sequences identified in the perv gag precursor. the proteases of all perv subtypes consist of 127 amino acid residues with an m(r ... | 2002 | 12097607 |
| microchimerism and transmission of porcine endogenous retrovirus from a pig cell line or specific pathogen-free pig islets to mouse tissues and human cells during xenografts in nude mice. | pig islets could transmit porcine endogenous retroviruses (perv) to diabetic patients. our previous work showed that pig islets expressed low levels of perv mrna and were not likely to transmit perv to human cells in vitro. the real risk of infection during pig tissue xenografts can only be evaluated by in vivo experiments. | 2002 | 12107737 |
| virus safety in xenotransplantation: first exploratory in vivo studies in small laboratory animals and non-human primates. | for xenotransplantation, the transplantation of animal cells, tissues and organs into human recipients, to date, pigs are favored as potential donors. beside ethical, immunological, physiological and technical problems, the microbiological safety of the xenograft has to be guaranteed. it will be possible to eliminate all of the known porcine microorgansims in the nearby future by vaccinating or specified pathogen-free breeding. thus, the main risk will come from the porcine endogenous retrovirus ... | 2002 | 12180842 |
| pcr-based cloning and immunocytological titration of infectious porcine endogenous retrovirus subgroup a and b. | two pig endogenous retroviruses (perv), perv-a and -b, productively infect human cells and are therefore considered to constitute a potential risk in pig-to-human xenotransplantation. a pcr-based cloning technique to isolate infectious perv proviruses was established. overlapping 3' half and 5' halves of perv proviral genomes were amplified using dna extracted from human 293 cells infected with perv-a or -b. these clones were fused at a unique restriction site in the overlapping region and teste ... | 2002 | 12185278 |
| development of a real time quantitative pcr assay for detection of porcine endogenous retrovirus. | real time pcr technology was applied to the development of assays for detection and quantitation of porcine endogenous retrovirus (perv) rna and dna sequences in tissues and cells of human or animal origin. a plasmid construct encoding the perv-pol gene or the in vitro transcribed rna derived from the plasmid (crna) serves as a standard template for amplification of a 178 bp fragment. this study showed that the detection of this target sequence was linear over a range from 20 copies to 2 million ... | 2002 | 12367734 |
| porcine endogenous retrovirus--advances, issues and solutions. | 2002 | 12371932 | |
| porcine endogenous retrovirus infects but does not replicate in nonhuman primate primary cells and cell lines. | porcine endogenous retroviruses (perv) can infect human cell lines in vitro; hence, there is a presumed risk of viral exposure to a recipient when pig cells are transplanted into humans (xenotransplantation). nonhuman primates (nhp) are considered a potential permissive animal model to study the risk of in vivo infection of perv after xenotransplantation. we set out to determine whether perv can infect and replicate in nhp primary cells or established cell lines from african green monkey, rhesus ... | 2002 | 12388691 |
| characterization of porcine endogenous retrovirus gamma pro-pol nucleotide sequences. | endogenous retroviral sequences in the pig genome (perv) represent a potential infectious risk in xenotransplantation. all known infectious perv have been asssigned to the perv gamma1 family, consisting of the subfamilies a, b, and c. the aim of the study was the concise examination of perv gamma by the analysis of the retroviral pro-pol sequences. the analysis of 52 pro-pol clones amplified in this study revealed eight perv gamma families. in addition to four already-described families (gamma1, ... | 2002 | 12388734 |
| case-control study on the association of porcine circovirus type 2 and other swine viral pathogens with postweaning multisystemic wasting syndrome. | a field-based case-control study was conducted to assess the strength of association of porcine circovirus type 2 (pcv2) and some major swine viruses with postweaning multisystemic wasting syndrome (pmws). cases were defined as individual pigs with a clinical history of progressive weight loss and histopathological lesions characteristic of pmws. controls were pigs without clinical signs and histopathological lesions typical of pmws. a total of 31 cases and 56 controls was identified from diagno ... | 2002 | 12423025 |
| transcriptional regulation of porcine endogenous retroviruses released from porcine and infected human cells by heterotrimeric protein complex nf-y and impact of immunosuppressive drugs. | recent studies revealed a significant promoter activity of porcine endogenous retrovirus (perv) long terminal repeats (ltrs) in different human and mammalian cell lines, which is mediated by a 39-bp repeat located in the u3 region in different numbers, representing an enhancer (g. scheef, n. fischer, u. krach, and r. r. tönjes, j. virol. 75:6933-6940, 2001). a statistical transcription factor analysis revealed putative binding sites for the ccaat-binding transcription factor nf-y inside the 39-b ... | 2002 | 12438581 |
| bioartificial liver support anno 2001. | despite maximal intensive care, mortality of acute fulminant hepatic failure is high: 60%-75% in several studies. in addition patients with chronic liver insufficiency suffer from a bad quality of life: all patients suffer from fatigue; symptoms of hepatic encephalopathy, jaundice, and itching are often present. analogous to artificial kidney treatment in patients with renal failure, an artificial liver assist device is needed not only to bridge patients with fulminant hepatic failure to liver t ... | 2002 | 12602524 |
| susceptibility of recombinant porcine endogenous retrovirus reverse transcriptase to nucleoside and non-nucleoside inhibitors. | transplantation of organs, tissues or cells from pigs to humans could be a potential solution to the shortage of human organs for transplantation. porcine endogenous retroviruses (pervs) remain a major safety concern for porcine xenotransplantation. thus, finding drugs that could be used as virological prophylaxis (or therapy) against perv replication would be desirable. one of the most effective ways to block retroviral multiplication is to inhibit the enzyme reverse transcriptase (rt) which ca ... | 2002 | 12568344 |
| susceptibility of the porcine endogenous retrovirus to reverse transcriptase and protease inhibitors. | porcine xenografts may offer a solution to the shortage of human donor allografts. however, all pigs contain the porcine endogenous retrovirus (perv), raising concerns regarding the transmission of perv and the possible development of disease in xenotransplant recipients. we evaluated 11 antiretroviral drugs licensed for human immunodeficiency virus type 1 (hiv-1) therapy for their activities against perv to assess their potential for clinical use. fifty and 90% inhibitory concentrations (ic(50) ... | 2001 | 11134319 |
| evidence of porcine endogenous retroviruses in porcine factor viii and evaluation of transmission to recipients with hemophilia. | since 1984, unheated porcine clotting factor viii (hyate:c) has been used to treat severe bleeding episodes in persons with hemophilia who have antibodies to human clotting factor. we document the presence of porcine endogenous retrovirus (perv) in plasma samples of pigs and in clinical lots of hyate:c. both gag and pol perv rna sequences were detected by reverse-transcriptase (rt) polymerase chain reaction in 13 of 13 lots of hyate:c tested. among 10 of these lots, rt activity also was detected ... | 2001 | 11170992 |
| the number of a u3 repeat box acting as an enhancer in long terminal repeats of polytropic replication-competent porcine endogenous retroviruses dynamically fluctuates during serial virus passages in human cells. | the organization and transcriptional regulation of porcine endogenous retrovirus (perv) long terminal repeats (ltrs) are unknown. we have studied the activity of ltrs from replication-competent molecular clones by performing luciferase reporter assays. the ltrs differ in the presence and number of 39-bp repeats located in u3 that confer strong promoter activity in human, simian, canine, feline, and porcine cell lines, whereas for ltrs devoid of the repeats, the promoter strength was significantl ... | 2001 | 11435573 |
| the porcine endogenous retrovirus long terminal repeat contains a single nucleotide polymorphism that confers distinct differences in estrogen receptor binding affinity between perv a and perv b/c subtypes. | porcine endogenous retroviruses (perv) have been shown to have zoonotic potential, both in vitro and in vivo. once integrated into the host cell genome activation of the proviral genes is ultimately dependent upon transactivation of the long terminal repeat (ltr). currently there is no direct evidence of host cell transcription factors interacting with perv ltrs. using comparative genomics we discovered a potentially functional single nucleotide polymorphism (snp) within the u5 region downstream ... | 2001 | 11448161 |
| identification of a novel type c porcine endogenous retrovirus: evidence that copy number of endogenous retroviruses increases during host inbreeding. | different classes of porcine endogenous retroviruses (pervs), which have the potential to infect humans during xenotransplantation, have been isolated from the pig genome. because vertebrate genomes may contain numerous endogenous retrovirus sequences, the pig genome was examined for additional endogenous retroviruses, resulting in the isolation of a novel, complete endogenous retrovirus genome, designated perv-e. the gag, pol and env genes of perv-e are closely related to those of human endogen ... | 2001 | 11457988 |
| characterization of a porcine lung epithelial cell line suitable for influenza virus studies. | we established a porcine lung epithelial cell line designated st. jude porcine lung cells (sjpl) and demonstrated that all tested influenza a and b viruses replicated in this cell line. the infectivity titers of most viruses in sjpl cells were comparable to or better than those in mdck cells. the propagation of influenza viruses from clinical samples in sjpl cells did not lead to antigenic changes in the hemagglutinin molecule. the numbers of both sia2-3gal and sia2-6gal receptors on sjpl cells ... | 2001 | 11533214 |
| mapping full-length porcine endogenous retroviruses in a large white pig. | xenotransplantation may bridge the widening gap between the shortage of donor organs and the increasing number of patients waiting for transplantation. however, a major safety issue is the potential cross-species transmission of porcine endogenous retroviruses (perv). this problem could be resolved if it is possible to produce pigs that do not contain replication-competent copies of this virus. in order to determine the feasibility of this, we have determined the number of potentially replicatio ... | 2001 | 11711616 |
| porcine endogenous retroviruses (pervs): generation of specific antibodies, development of an immunoperoxidase assay (ipa) and inhibition by azt. | xenotransplantation may be associated with the risk of transmission of microorganisms. in particular, the porcine endogenous retroviruses (perv) have raised concerns as in vitro experiments show susceptibility of human cells for perv infection. however, it remains unclear whether pervs are able to infect transplant recipients in vivo and whether they are pathogenic. it is therefore essential that the risks are evaluated and for this purpose specific and sensitive screening methods for pervs have ... | 2001 | 11737857 |
| in vivo analysis of porcine endogenous retrovirus expression in transgenic pigs. | xenotransplantation offers a potential solution to the shortage of donor organs for allotransplantation. in vitro studies that demonstrate the transmission of porcine endogenous retroviruses (perv) from porcine cells to human cells and cell lines have raised concerns regarding the potential transmission of perv to both xenograft recipients and their contacts (1-4). while no evidence of infection has been detected in any patients who have been treated with a variety of different porcine tissues ( ... | 2001 | 11773903 |
| identification of novel porcine endogenous betaretrovirus sequences in miniature swine. | pcr amplification of genomic dna from miniature swine peripheral blood lymphocytes, using primers corresponding to highly conserved regions of the polymerase (pol) gene, allowed the identification of two novel porcine endogenous retrovirus (perv) sequences, pmsn-1 and pmsn-4. phylogenetic analyses of the nucleotide sequences of pmsn-1 and pmsn-4 revealed them to be most closely related to betaretroviruses. the identification of pervs belonging to the betaretrovirus genus shows that endogenous re ... | 2001 | 11222699 |
| multiple groups of novel retroviral genomes in pigs and related species. | in view of the concern over potential infection hazards in the use of porcine tissues and organs for xenotransplantation to humans, we investigated the diversity of porcine endogenous retrovirus (perv) genomes in the dna of domestic pigs and related species. in addition to the three known envelope subgroups of infectious gamma retroviruses (perv-a, -b, and -c), classed together here as perv group gamma 1, four novel groups of gamma retrovirus (gamma 2 to gamma 5) and four novel groups of beta re ... | 2001 | 11222700 |
| monitoring xenotransplant recipients for infection by perv. | concerns have been raised over the possibility of transmission of porcine endogenous retrovirus (perv) to porcine xenograft recipients. | 2001 | 11239511 |
| porcine endogenous retroviruses: in vitro host range and attempts to establish small animal models. | using transgenic pigs as the source of cells or organs for xenotransplantation is associated with the risk of porcine endogenous retrovirus (perv) transmission. multiple proviruses are integrated into the genome of all pigs, and virus particles, some of which are able to infect human cells, are released from normal pig cells. in order to evaluate the potential risk posed by the transmission of pervs, in vitro infection studies were performed as a basis for small animal as well as non-human prima ... | 2001 | 11257189 |
| analysis of potential porcine endogenous retrovirus (perv) transmission in a whole-organ xenotransplantation model without interfering microchimerism. | the question whether porcine xenografts can lead to porcine endogenous retrovirus (perv) infection of recipients is critical for the evaluation of the safety of pig-to-man xenotransplantation. unfortunately, polymerase chain reaction (pcr)-based analysis of potential perv infections in nonhuman-primate whole-organ xenotransplantation models is hampered by false positive results due to chimeric porcine cells. to avoid the inherent analytical problem of xenomicrochimerism, we developed a non-life- ... | 2001 | 11263553 |
| altered infectivity of porcine endogenous retrovirus by "protective" avian antibodies: implications for pig-to-human xenotransplantation. | 2001 | 11267019 |