• Korean Journal of Agricultural Science
• /
• v.36 no.2
• /
• pp.159-165
• /
• 2009

This study was conducted to identify the PERV (Porcine Endogenous Retrovirus) integration sites and their characterizations using the porcine genomic sequence information. Total 114 Mb (4.2%) sequence of the 2.7 Gb pig genome was investigated for the PERV sequences. As the results, 8 PERV sequences were identified and their genomic structures were deduced from the BLAST searches against previously known PERV genes. Seven PERVs have internal deletions in the protein coding region and they will not be functional. The other one also has internal deletions in the gag and env genes, indicating this PERV is also defective. Even though we could not identify the functional PERVs in this study, the results presented here can be used for the fundamental research materials for controlling PERV infections in relation to xenotransplantation using porcine organs and tissues.

• Molecules and Cells
• /
• v.27 no.1
• /
• pp.119-123
• /
• 2009

Porcine endogenous retroviruses (PERVs) gamma1 in the pig genome have the potential to act as harmful factors in xenotransplantation (pig-to-human). Long terminal repeats (LTRs) are known to be strong promoter elements that could control the transcription activity of PERV elements and the adjacent functional genes. To investigate the transcribed PERV gamma1 LTR elements in pig tissues, bioinformatic and experimental approaches were conducted. Using RT-PCR amplification and sequencing approaches, 69 different transcribed LTR elements were identified. And 69 LTR elements could be divided into six groups (15 subgroups) by internal variation including tandem repeated sequences, insertion and deletion (INDEL). Remarkably, all internal variations were indentified in U3 region of LTR elements. Taken together, the identification and characterization of various PERV LTR transcripts allow us to extend our knowledge of PERV and its transcriptional study.

• Asian-Australasian Journal of Animal Sciences
• /
• v.21 no.11
• /
• pp.1572-1575
• /
• 2008

The xenotransplantation of pig organs and cells can be related with a risk of transmission of infectious diseases to human. Previous findings indicate that the regulatory region of PERV for retroviral transcription, replication and integration into the cellular DNA is located on the 5' Long Terminal Repeat (LTR). The objective of this study is the investigation of methylation and deletion status of the PERV 5' LTR region which can be used for regulating PERV expression. We compared the sequences of genomic DNA and bisulfite-treated genomic DNA from PK-15 cells expressing PERV to observe the methylation status of the 5' LTR. Our results showed that the CpG sites of U3 were methylated and methylation was inconsistent in the R and U5 regions. Also, variable numbers of 18 bp repeats and 21 bp repeats were detected on 5' LTR by sequencing analysis. The consistent U3 methylation might be indicative of host suppression of expression of the retroviruses.

• Journal of Chest Surgery
• /
• v.42 no.2
• /
• pp.165-174
• /
• 2009

Background: With the advances of cardiac surgery, the demand for an artificial prosthesis has increased, and this has led to the development and utilization of diverse alternative materials. We conducted this research to improve an artificial prosthesis by examining the changes of the physical qualities, the pressure related tensile strength, the change in elasticity and the thermostability of a xenograft valve (porcine) and pericardium (bovine, porcine) based on the type of fixation liquid we used. Material and Method: The xenograft valves and pericardium were assigned into three groups: the untreated group, the fixed with glutaraldehyde (GA) group and the glutaraldehyde with GA+solvent such as ethanol etc. group. The surgeons carried out each group's physical activities. Each group's uniaxial tension and elasticity was measured and compared. Thermostability testing was conducted and compared between the bovine and porcine pericardium fixed with GA group and the GA+solvent group. Result: On the physical activity test in the surgeon's hand, no significant difference between the groups was sensed on palpation. For suture and tension, the GA+solvent group was slightly firmer than the low GA concentration group. In general, the circumferential uniaxial tension and elasticity of the porcine aortic and pulmonary valves were better in the fixed groups than that in the untreated group. There was no significant difference between the GA and GA+solvent groups (p>0.05). Bovine and porcine pericardium also showed no significant difference between the GA group and the GA+solvent group (p>0.05). When comparing between the groups for each experiment, the elasticity tended to be stronger in most of the higher GA concentration group (porcine pulmonary valve, porcine pericardium). On the thermostability testing of the bovine and porcine pericardium, the GA group and the G+solvent group both had a sudden shrinking point at $80^{\circ}C$ that showed no difference (bovine pericardium: p=0.057, porcine pericardium: p=0.227). Conclusion: When fixing xenograft prosthetic devices with GA, adding a solvent did not cause a loss in pressure-tension, tension-elasticity and thermostability. In addition, more functional solvents or cleansers should be developed for developing better xenografts.

• Journal of Chest Surgery
• /
• v.39 no.2 s.259
• /
• pp.99-105
• /
• 2006

Background: Interrupted aortic arch is a rare congenital heart anomaly which still shows high surgical mortality. In this study, we investigated the causes of and the risk factors for mortality to improve the surgical outcomes for this difficult disease entity. Material and Method: From 1984 to 2004, 42 patients diagnosed as IAA were reviewed retrospectively. Age, body weight at operation, preoperative diagnosis, preoperative PGE1 requirement, type of interrupted aortic arch, degree of left ventricular outflow stenosis, CPB time, and ACC time were the possible risk factors for mortality. Result: There were .14 hospital deaths. Preoperative use of PGE1, need for circulartory assist and aortic cross clamp time proved to be positive risk factors for mortality on univariate analysis. Preoperative left ventricular outflow stenosis was considered a risk factor for mortality but it did not show statistical significance (p-value=0.61). Causes of death included hypoxia due to pulmonary banding, left ventricular outtract stenosis, infection, mitral valve regurgitation, long cardiopulmonary bypass time and failure of coronary transfer failure in TGA patients. Conclusion: In this study, we demonstrated that surgical mortality is still high due to the risk factors including preoperative status and long operative time. However preoperative subaortic dimension was not related statistically to operative death statistically. Adequate preoperative management and short operation time are mandatory for better survival outcome.

• Journal of Chest Surgery
• /
• v.38 no.8 s.253
• /
• pp.538-544
• /
• 2005

Background: Pulmonary artery banding (PAB) is an initial palliative procedure for a diverse group of patients with congenital cardiac anomalies and unrestricted pulmonary blood flow. We proved the usefulness of PAB through retrospective investigation of the surgical indication and risk analysis retrospectively. Material and Method: One hundred and fifty four consecutive patients (99 males and 55 females) who underwent PAB between January 1986 and December 2003 were included. We analysed the risk factors for early mortality and actuarial survival rate. Mean age was $2.5\pm12.8\;(0.2\sim92.7)$ months and mean weight was $4.5\pm2.7\;(0.9\sim18.0)\;kg$. Preoperative diagnosis included functional single ventricle $(88,\;57.1\%)$, double outlet right ventricle $(22,\;14.2\%)$, transposition of the great arteries $(26,\;16.8\%)$, and atrioventricular septal defect $(11,\;7.1\%)$. Coarctation of the aorta or interrupted aortic arch $(32,\;20.7\%)$, subaortic stenosis $(13,\;8.4\%)$ and total anomalous pulmonary venous connection $(13,\;8.4\%)$ were associated. Result: The overall early mortality was $22.1\%\;(34\;of\;154)$, The recent series from 1996 include patients with lower age $(3.8\pm15.9\;vs.\;1.5\pm12.7,\;p=0.04)$ and lower body weight $(4.8\pm3.1\;vs.\;4.0\pm2.7,\;p=0.02)$. The early mortality was lower in the recent group $(17.5\%;\;16/75)$ than the earlier group $(28.5\%;\;18/45)$. Aortic arch anomaly (p=0.004), subaortic stenosis (p=0.004), operation for subaortic stenosis (p=0.007), and cardiopulmonary bypass (p=0.007) were proven to be risk factors for early death in univariate analysis, while time of surgery (<1996) (p=0.026) was the only significant risk factor in multivariate analysis. The mean time interval from PAB to the second-stage operation was $12.8\pm10.9$ months. Among 96 patients who survived PAB, 40 patients completed Fontan operation, 21 patients underwent bidirectional cavopulmonary shunt, and 35 patients underwent biventricular repair including 25 arterial switch operations. Median follow-up was $40.1\pm48.9$ months. Overall survival rates at 1 year, 5 years and 10 years were $81.2\%\;65.0\%,\;and\;63.5\%$ respectively. Conclusion: Although it improved in recent series, early mortality was still high despite the advances in perioperative management. As for conventional indications, early primary repair may be more beneficial. However, PA banding still has a role in the initial palliative step in selective groups.

• Journal of Animal Science and Technology
• /
• v.49 no.3
• /
• pp.405-414
• /
• 2007

Pigs have been considered as an ideal source of donor organs because of their plentiful supply and their numerous anatomical and physiological similarities to the human in xenotransplantation. However, for the public health risks associated with the potential for porcine endogenous retrovirus(PERV) infection through xenograft from pig to human, the investigation of methods for elimination and/or control of PERV has been required. In this study we developed the detection and classification methods for PERV based on PCR using specific primers. PERV-A and PERV-B were found in all pigs including Berkshire, Duroc, Landrace, Yorkshire, miniature pig, and Korean native black pig from Jeju by PCR with type-specific primers for PERV. However, PERV-C was detected only from Duroc, miniature pig, and Korean native black pig from Jeju. PERV-A and PERV-B could be distinguished by PCR-RFLP with BamHI. These methods for PERV will be useful in rapid screening of safe organ for xenograft, furthermore, helpful in monitoring of PERV during and after xenotransplantation.

• Journal of Animal Science and Technology
• /
• v.46 no.3
• /
• pp.307-314
• /
• 2004

Xenotransplantation of porcine organs has the potential to overcome the severe. shortage of human tissues and organs available for human transplantation. The swine represents an ideal source of such organs because of their plentiful supply and their numerous anatomical and physiological similarities to the human. However, this procedure also carries with a number of safety issues relating to the zoonotic infections. Porcine endogenous retrovinJses(PERVs), \Wich are germ line transmitted and persist without symptoms in the pigs, are most concerning zoonotic viroses. In order to analyze the prevalence of PERV in domestic pigs, four kinds of pigs'(Landrace, Berkshire, Yorkshire, and Duroc) genomic DNA were isolated from their hair follicles. PCR analysis was carried out for detection of PERVs using subgroup A/B/C and E pol sequence primers. All pigs (20 heads) tested had high copy number of PERVs within genomes. Subgroup A/B/C and E pol gene sequences from 20 isolates were determined by direct sequencing. Sequence analysis showed pol sequences are highly conserved among intra- and inter-subspecies(99.l and 98.8%, respectively). As a first report of PERV prevalence in Korea pigs, our data would be the basic concepts of PERV transmission study in xenotransplantation.

• Reproductive and Developmental Biology
• /
• v.39 no.3
• /
• pp.59-67
• /
• 2015

Galactose-${\alpha}1,3$-galactose (${\alpha}1,3$-Gal) epitope is synthesized at a high concentration on the surface of pig cells by ${\alpha}1,3$-galactosyltransferase gene (GGTA1). The ${\alpha}1,3$-Gal is responsible for hyperacute rejection in pig-to-human xenotransplantation. The generation of transgenic pigs as organ donors for humans is necessary to eliminate the GGTA1 gene that synthesize $Gal{\alpha}$(1,3)Gal. To prevent hyperacute graft rejection in pig-to-human xenotransplantation, previously, we developed ${\alpha}1,3$-galactosyltransferase gene-knock-out somatic cell by homologous recombination. In this study, we established cell lines of ${\alpha}1,3$-GT knock-out expressing hDAF and hHT gene from minipig fibroblasts to apply somatic cell nuclear transfer. The hDAF and hHT mRNA were expressed in the knock-in somatic cells and ${\alpha}1,3$-GT mRNA was suppressed. However, the knock-in somatic cells were increased resistance to human serum-mediated cytolysis.

• Journal of Animal Science and Technology
• /
• v.47 no.2
• /
• pp.177-186
• /
• 2005

Xenotransplantation may help to overcome the critical shortage of human tissues and organs for human transplantation, Swine represents an ideal source of such organs owing to their anatomical and physiological similarities to human besides their plentiful supply, However, the use of organs across the species barrier may be associated with the risk of transmission of pathogens, specially porcine endogenous retroviruses (PERVs).• Although most of these potential pathogens could be eliminated by pathogen-free breeding, PERVs are not eliminated by this treatment. PERVs are integrated into the genome of all pigs and produced by normal pig cells and infect human cells. They belong to gamma retroviruses and are of three classes viruses: A, B and C. In the present study, PCR based cloning was performed with chromosomal DNA extracted from pigs from domestic pigs in Korea. Amplified PCR fragments of about 1.5 Kb, covering the partial env gene, were cloned into pCR2.l-TOPO vectors and sequenced. A total of 91 env clones were obtained from domestic pigs, Berkshire, Duroc, Landrace and Yorkshire in Korea. Phylogenetic analysis of these genes revealed the presence of only PERV class A and B in the proportion of 58 % and 42 %, respectively. Among these, 28 clones had the correct open reading frame: 18 clones in class A and 10 clones in class B. Since both these PERV classes are polytropic and have the capacity to infect human cells, our data suggest that proviral PERVs have the potential to generate infectious viruses during or after xenotransplantation in human.