• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.140-145
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• 2017

The goal of this study was to investigate risk factors associated with porcine reproductive and respiratory syndrome (PRRS) in pig farms in the Republic of Korea using logistic regression and a multilevel model. A cross-sectional study was applied to 305 pig farms with a questionnaire-based interview by veterinarians between March 2014 and February 2015. The questionnaire comprised eight categories: proximity to neighbors, disinfection, visitors, vehicles, insecticides, wild animals, gilts, and feeding. In total, 61 questions in eight categories related to pig farm biosecurity were investigated. Farms were classified as PRRS stable or unstable based on the results of an antibody test and PCR. For univariate analysis, keeping production records with computers (OR = 0.283, 95% CI = 0.056 - 1.425), accredited farm with no use of antibiotics (OR = 0.412, 95% CI = 0.134 - 1.269), reviewing health record of semen prior to purchasing (OR = 0.492, 95% CI = 0.152 - 1.589), complete isolation of runt pigs (OR = 0.264, 95% CI = 0.084 - 0.829), compulsory registering for visitors (OR = 0.424, 95% CI = 0.111 - 1.612), keeping records of insecticide history (OR = 0.406, 95% CI = 0.089 - 1.846), routine on-farm monitoring by veterinarians (OR = 0.314, 95% CI = 0.069 - 1.423), and use of on-farm checklist for biosecurity monitoring (OR = 0.313, 95% CI = 0.063 - 1.553) were found to decrease the probability of PRRS infection. Multivariate and multilevel analysis revealed only two factors, complete isolation of runt pigs (OR = 0.165, 95% CI = 0.045 - 0.602 and OR = 0.208, 95% CI = 0.055 - 0.782) and compulsory registering for visitors (OR = 0.106, 95% CI = 0.017 - 0.655 and OR = 0.119, 95% CI = 0.017 - 0.809) were found to decrease the probability of PRRS infection. The intracluster correlation coefficient of a province for multilevel model was 0.05. The results of this study might facilitate biosecurity measures for individual farms to reduce the probability of PRRS infection.

• Korean Journal of Veterinary Service
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• v.45 no.1
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• pp.31-38
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• 2022

Swine influenza (SI) is an important respiratory disease in pigs and epidemic worldwide, which is caused by influenza A virus (IAV) belonging to the family of Orthomyxoviridae. As seen again in the 2009 swine-origin influenza A H1N1 pandemic, pigs are known to be susceptible to swine, avian, and human IAVs, and can serve as a 'mixing vessel' for the generation of novel IAV variants. To this end, the emergence of swine influenza viruses must be kept under close surveillance. Herein, we report the isolation and phylogenetic study of a swine IAV, A/swine/Korea/21810/2021 (sw21810, H3N2 subtype). BLASTN sequence analysis of 8 gene segments of the isolated virus revealed a high degree of nucleotide similarity (94.76 to 100%) to porcine strains circulating in Korea and the United States. Out of 8 genome segments, the HA gene was closely related to that of isolates from cluster I. Additionally, the NA gene of the isolate belonged to a Korean Swine H1N1 origin, and the PB2, PB1, NP and NS genes of the isolate were grouped into that of the Triple reassortant swine H3N2 origin virus. The PA and M genes of the isolate belonged to 2009 Pandemic H1N1 lineage. Human infection with mutants was most common through contact with infected pigs. Our results suggest the need for periodic close monitoring of this novel swine H3N2 influenza virus from a public health perspective.

• The Journal of the Korean bone and joint tumor society
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• v.1 no.1
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• pp.7-16
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• 1995

In countries where confucianism is popular, it is extremely hard to get fresh cadaver bone for allograft. Therefore in Korea, the reimplantation of resected autoclaved autogenous bone segments has been increasingly performed for limb reconstruction of extremities with malignancies. To preserve the bone morphogenetic protein and mechanical strength of heated bone, many studies have reported that pasteurization of bone is far better than autoclaving over $100^{\circ}C$. Based on this assumption, replacement with a pasteurized autogenous bone graft after resection of a malignant bone tumor was deemed feasible for reconstruction. However, little is known about how high a temperature and how much time for pasteurization is needed to make tumors completely necrotic and to maintain the mechanical strength of bone. Consequantly, experimental studies were carried out to test heat conductivity of human bone and torsional strength of porcine tibia after pasteurization. First, two pairs of human proximal tibia and distal femur were used. We used T-type thermocoples to check core temperature of the bone and a computerized data acquisition system to record results. Without reaming of the medullary cavity, in a $60^{\circ}C$-thermostatic saline tub, it took 32 minutes and 50 seconds to raise the core temperature of human proximal tibia from $20^{\circ}C$ to $58^{\circ}C$, and 30 minutes for distal femur. In a $80^{\circ}C$ saline tub, it took 12 minutes and 50 seconds for proximal tibia, and 11 minutes and 10 seconds for distal femur. In contrast, using porcine tibia whose cortical thickness is similar to that of human tibia, after reaming of the medullary canal, it took less than 3 minutes and 30 seconds in a $60^{\circ}C$ saline tub, less than 1 minute and 45 seconds in a $70^{\circ}C$ tub, and less than 1 minute in a $80^{\circ}C$ tub to elevate core temperature from $20^{\circ}C$ to $58^{\circ}C$. Second, based on data of the heat conductivity test, we compared the torsional strength before and after pasteurization. Twenty matched pairs of porcine tibia were used, The left one was used as a non-heated control group and the right one as a pasteurized experimental group. Wighout reaming of the medullary cavity, there was no statistical difference in torsional strength between the pasteurization of the $60^{\circ}C$-35minute and of $80^{\circ}C$-15minute. With reaming, we also found no statistical difference among pasteurization of $60^{\circ}C$-15 minute, of $70^{\circ}C$-15 minute, and of $80^{\circ}C$-15 minute groups. In conclusion, reaming of the medullary canal is very helpful in saving pasteurization time. And, in a $60^{\circ}C$ saline tub, no significant weakness in torsional strength occurs with pasteurization of the bone for up to 35 minutes. Also no significant weakness in torsional strength occurs with an exposure of 15 minutes to the $80^{\circ}C$ saline tub.

• Journal of Periodontal and Implant Science
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• v.40 no.5
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• pp.232-238
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• 2010

Purpose: To prolong the degradation time of collagen membranes, various cross-linking techniques have been developed. For cross-linking, chemicals such as formaldehyde and glutaraldehyde are added to collagen membranes, but these chemicals could adversely affect surrounding tissues. The aim of this study is to evaluate the ability of porous non-chemical cross-linking porcine-derived collagen nanofibrous membrane to enhance bone and associated tissue regeneration in one-wall intrabony defects in beagle dogs. Methods: The second and third mandibular premolars and the first molars of 2 adult beagles were extracted bilaterally and the extraction sites were allowed to heal for 10 weeks. One-wall intrabony defects were prepared bilaterally on the mesial and distal side of the fourth mandibular premolars. Among eight defects, four defects were not covered with membrane as controls and the other four defects were covered with membrane as the experimental group. The animals were sacrificed 10 weeks after surgery. Results: Wound healing was generally uneventful. For all parameters evaluating bone regeneration, the experimental group showed significantly superior results compared to the control. In new bone height (NBh), the experimental group exhibited a greater mean value than the control ($3.04{\pm}0.23\;mm/1.57{\pm}0.59$, P=0.003). Also, in new bone area (NBa) and new bone volume (NBv), the experimental group showed superior results compared to the control (NBa, $34.48{\pm}10.21%$ vs. $5.09{\pm}5.76%$, P=0.014; and NBv, $28.04{\pm}12.96$ vs. $1.55{\pm}0.57$, P=0.041). On the other hand, for parameters evaluating periodontal tissue regeneration, including junctional epithelium migration and new cementum height, there were no statistically significant differences between two groups. Conclusions: Within the limitations of this study, this collagen membrane enhanced bone regeneration at one-wall intrabony defects. On the other hand, no influence of this membrane on periodontal tissue regeneration could be ascertained in this study.

• Journal of Periodontal and Implant Science
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• v.48 no.2
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• pp.84-91
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• 2018

Purpose: The purpose of this study was to visualize and identify peri-implant bone defects in optical coherence tomography (OCT) images and to obtain quantitative measurements of the defect depth. Methods: Dehiscence defects were intentionally formed in porcine mandibles and implants were simultaneously placed without flap elevation. Only the threads of the fixture could be seen at the bone defect site in the OCT images, so the depth of the peri-implant bone defect could be measured through the length of the visible threads. To analyze the reliability of the OCT measurements, the flaps were elevated and the depth of the dehiscence defects was measured with a digital caliper. Results: The average defect depth measured by a digital caliper was $4.88{\pm}1.28mm$, and the corresponding OCT measurement was $5.11{\pm}1.33mm$. Very thin bone areas that were sufficiently transparent in the coronal portion were penetrated by the optical beam in OCT imaging and regarded as bone loss. The intraclass correlation coefficient between the 2 methods was high, with a 95% confidence interval (CI) close to 1. In the Bland-Altman analysis, most measured values were within the threshold of the 95% CI, suggesting close agreement of the OCT measurements with the caliper measurements. Conclusions: OCT images can be used to visualize the peri-implant bone level and to identify bone defects. The potential of quantitative non-invasive measurements of the amount of bone loss was also confirmed.

• Asian-Australasian Journal of Animal Sciences
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• v.29 no.3
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• pp.321-326
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• 2016

The porcine major histocompatibility complex (MHC) is called swine leukocyte antigen (SLA), which controls immune responses and transplantation reactions. The SLA is mapped on pig chromosome 7 (SSC7) near the centromere. In this study, 3 class I (SLA-1, SLA-3, and SLA-2) and 3 class II (DRB1, DQB1, and DQA) genes were used for investigation of SLA haplotypes in Yucatan miniature pigs in Korea. This pig breed is a well-known model organism for biomedical research worldwide. The current study indicated that Korean Yucatan pig population had 3 Class I haplotypes (Lr-4.0, Lr-6.0, and Lr-25.0) and 3 class II haplotypes (Lr-0.5, Lr-0.7, and Lr-0.25). The combinations of SLA class I and II haplotype together, 2 homozygous (Lr-4.5/4.5 and Lr-6.7/6.7) and 3 heterozygous (Lr-4.5/6.7, Lr-4.5/25.25, and Lr-6.7/25.25) haplotypes were identified, including previously unidentified new heterozygous haplotypes (Lr-4.5/4.7). In addition, a new SLA allele typing method using Agilent 2100 bioanalyzer was developed that permitted more rapid identification of SLA haplotypes. These results will facilitate the breeding of SLA homozygous Yucatan pigs and will expedite the possible use of these pigs for the biomedical research, especially xenotransplantation research.

• Journal of Microbiology and Biotechnology
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• v.6 no.1
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• pp.7-11
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• 1996

MR-387Al (ARPA-Val-Pro) and A2 (AHPA-Val-Hyp) were prepared as aminopeptidase N inhibitors through the synthesis of peptide MR-387A and B analogues which contained 3-amino-2-hydroxy-4-phenyl butanoic acid (ARPA) as a zinc-chelating moiety. They are competitive inhibitors of aminopeptidase N with inhibition constants(Ki) of 4.1 $\times 10^{-7}\;and 1.1 \times 10^{-6}$ M, respectively. MR-387Al also strongly inhibited aminopeptidase B of human myelogenous leukemia K-562 cell with $IC_50$ of 0.35 $\mu$ M. Inhibitions of aminopeptidase N activity by ARPA-bearing inhibitors of various peptide chain lengths also have been studied. $IC_ 50$ values of AHPA-Val (bestatin), ARPA-Val-Pro (MR-387Al) and ARPA-Val-Pro-Leu (MR-387C) compared against porcine kidney aminopeptidase N were 20.1, 0.60 and 0.08 $\mu$ M, respectively. These results support that a multiple interaction between the $S_1\to S'_3$ sites of aminopeptidase N and the $P_1\to P'_3$ of the inhibitor plays a crucial role in stabilizing strongly the enzyme-inhibitor complex.

• Imaging Science in Dentistry
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• v.44 no.2
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• pp.143-148
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• 2014

Purpose: This study evaluated the efficacy of alveolar ridge preservation methods with and without primary wound closure and the relationship between histometric and micro-computed tomographic (CT) data. Materials and Methods: Porcine hydroxyapatite with polytetrafluoroethylene membrane was implanted into a canine extraction socket. The density of the total mineralized tissue, remaining hydroxyapatite, and new bone was analyzed by histometry and micro-CT. The statistical association between these methods was evaluated. Results: Histometry and micro-CT showed that the group which underwent alveolar preservation without primary wound closure had significantly higher new bone density than the group with primary wound closure (P<0.05). However, there was no significant association between the data from histometry and micro-CT analysis. Conclusion: These results suggest that alveolar ridge preservation without primary wound closure enhanced new bone formation more effectively than that with primary wound closure. Further investigation is needed with respect to the comparison of histometry and micro-CT analysis.

• Journal of Veterinary Clinics
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• v.34 no.2
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• pp.126-131
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• 2017

This study investigated the incidence rate of umbilical hernia (UH) in pig farms and examined the effect of using them as breeding pigs on reproductive traits. The occurrence of UH ranged from 0.1% to 3.0% in pig farms investigated. UH pigs were found in almost all farms except for a single farm in Jeju Island. Spontaneously occurring UH pigs were selected and used for cross breeding tests. UH-related crosses and their progeny showed significant (P < 0.05) differences in gestation period, the numbers of piglets born and alive, and body weights at birth and $21^{st}$ day comparing to those of the control population. UH-related crosses showed longer gestation period, reduced numbers of piglets, and lighter body weights than those from the control population. Interestingly, reduced number of piglets was about one fourth, suggesting that UH inheritance might play a critical role as a lethal gene during embryogenesis. In addition, UH incidence rate in UH-related crosses was significantly (P < 0.05) higher than that in the control except for UH-cross3. However, in the progeny of control cross, a pig also had UH appearance, indicating that porcine UH might be inherited in recessive inheritance mode. Taken together, the results of this study indicate that UH is one of recessively inherited genetic defect that occurs at ordinary times in pig farms, suggesting that the use of UH animals as sire and/or dam may lead to economic losses due to increased gestation period, reduced numbers of piglets born and alive, and lower growth rates after birth of pigs.

• Journal of Animal Reproduction and Biotechnology
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• v.36 no.2
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• pp.69-75
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• 2021

Cryopreservation is a widely-used efficient means of long-term sperm preservation. However, unlike other types of semen, cryopreserved boar semen has reduced fertility and the efforts continue to optimize post-thawing sperm recovery. In this study, we evaluated the effects of various washing solutions (Hulsen solution, lab-made DPBS and commercial DPBS) on post-thawing porcine sperm kinematics (CASA system), viability (SYBR-14/PI) and acrosome integrity (PSA/FITC). We also examined the effect of washing-centrifugation on frozen-thawed semen kinematics. The results indicate that type of washing solution and post-thawing centrifugation alters parameters linked to sperm quality (total motility, progressive motility, viability and acrosome integrity). Significantly higher (p < 0.05) motility and progressive motility were obtained when cryopreserved semen was processed with Hulsen solution. The post-thaw percentage of live and intact acrosomal sperm was significantly higher in group 1 (Hulsen solution) as compared to other groups. Following thawing-centrifugation, the results showed significantly higher motility and progressive motility in group 1 than other groups. However, the latter two DPBS groups did not differ statistically. Taken together, Frozen-thawed spermatozoa motility, acrosome integrity and viability can be affected by the type of washing solution used. Moreover, centrifugation of frozen-thawed semen has an unfavorable effect on total motility and progressive motility.