• Korean Journal of Veterinary Pathology
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• v.5 no.2
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• pp.49-56
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• 2001

Ocular lesions induced in 40 specific-pathogen-free Marek's disease (MD) resistant chicks by inoculation at 1 day of age with very virulent strain of Marek's disease virus (WV) were pathologically examined. Grossly,24/40 (60%) chicks had white gel-like materials in the vitreous body, whereas thickening and discoloration of iris (gray eye) were not observed. Microscopically, characteristic ocular MD lesions were observed in choroid (27/40), ciliary (30/40) and iris (23/40) in which small focal inflammatory to diffuse neoplastic Iymphoid cells were infiltrated. Five out of 40 MDV-inoculated birds revealed necrotizing Iymphomas in choroid. These lesions consisted of necrotic and degenerating Iymphoblasts accompanied by intranuclear inclusion body. There was retinal atrophy and necrosis with inclusion body detected in necrotic ganglion, inner or outer nuclear and infiltrated Iymphoblast cells. Conjunctiva showed lymphoid cell infiltration in 29/40 chicks inoculated with MDV, Vitreous body exhibited mild to severe exudation of eosinophilic proteinaceous material in 24/40 chicks. These lesions were associated with Iymphoid cell infutration, edema and fibrosis of choroid. Pecten (7/40) and optic nerve (13/40) were infiltrated usually mildly with Iymphoid cells. From these results, very virulent strain, Md/5 of MDV caused high incidence of ocular lesions in MD resistant chicks. In addition, Md/5 induced exudation of proteinaceous material into the vitreous body and fibrosis of choroid. Necrotizing ocular Iymphoma lesions in choroid is the first report in the MD literature.

• Korean Journal of Veterinary Service
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• v.25 no.1
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• pp.87-96
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• 2002

In this study, we wanted to determine if the respirotropic JMK strain of infectious bronchitis virus(IBV), which has a spike glycoprotein gene that is 99% similar to the nephropathogenic Gray strain of IBV, could adapt and cause lesions in the kidney following intracloacal passage in chickens. Two day old specific pathogen free(SPF) cchickens were infected with Gray and JMK strains by the intraocular and cloacal route. Several tissue samples were collected at various times. Viruses were recovered from more tissues and earlier in the infection from chickens infected cloacally than chickens infected intraocularly. Virus was isolated from the kidney of chickens infected with Gray by the intraocular route and JMK by the intracloacal route, but not from chicken given JMK the intraocular route. Histopathologically, interstitial nephritis was observed in Gray infected chickens. However, viral RNA or antigen were not detected in the kidney by in situ hybridization and immunohistochemistry. We further passaged the JMK strain ten times in two day old SPF chickens using cloacal inoculation. We examined the virus titer and histopathological change in the kidney at each passage level. The amount of virus recovered from the kidney was stable throughout this serial passage and the passaged virus did not caused renal damage. Further, virus could not be isolated from the kidney when chickens were infected with the passaged virus by the intraocular route. We conclude that the JMK strain has a strict upper respiratory tract tropism since cloacal passage did not produce nephrotropism or nephropathogenicity.

• Journal of Oriental Neuropsychiatry
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• v.21 no.3
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• pp.87-93
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• 2010

Objectives : The oriental medicine Jangwonhwan originally described in the Korean medical text, DonguiBogam(amnesia chapter). Recently, a modified formula of Jangwonhwan(LMK02-Jangwonhwan), was shown to reduce $\beta$-amyloid deposition in the brain of Tg-APPswe/PS1dE9 mouse model for Alzheimer's disease. This experiment aimed to investigate the acute oral toxicity of LMK02 in SD rats by up-and-down procedure determinations. Methods : Quality control of tablet form of LMK02 was established by estimating indicative components, Ginsenoside Rg3 of Red Ginseng and Decursin of Angelicagigas Nakai. The toxicity of LMK02 was investigated in 6 week old, specific pathogen free(SPF), Sprageu-Dawley rats. 3 female rats received 5,000 mg/10 ml/kg of test substance and their death rate, clinical sings, weight changes and autopsy findings had been observed for 2 weeks. Results : Any specific symptoms or death were resulted in this experiment. No significant changes in rats' weight. No significant differences in atopsy. Conclusions : The minimum lethal dose(MLD) of LMK02 for female Sprauge-Dawley rats were more than 5,000mg/kg in this experiment.

• Journal of Veterinary Science
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• v.23 no.3
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• pp.49.1-49.13
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• 2022

Background: Porcine circovirus type 2 (PCV2) and Mycoplasma hyopneumoniae (MHP) are economically significant pathogens in the pig industry. The use of combined vaccines against PCV2 and MHP is one of the most effective ways of protecting pigs from both diseases, and it has become a part of general management. Objectives: This study evaluated the efficacy of two new bivalent vaccines of PCV2 and MHP (Myco-X and Myco-XD) in SPF pigs. Myco-X and Myco-XD are a combined vaccine of MHP with PCV2b and PCV2d, respectively. Methods: Sixteen pigs were divided into four groups: Myco-X-vaccinated challenged, Myco-XD-vaccinated challenged, unvaccinated challenged, and unvaccinated unchallenged. Two milliliters of Myco-X were administered intramuscularly, and 0.5 mL of Myco-XD was injected intradermally at 3 wk of age. The pigs were challenged with virulent PCV2d via the intramuscular and intranasal route 4 wk post-vaccination. Results: All vaccinated pigs showed effective reduction of the clinical signs, the PCV2d load in the blood and nasal swab samples, as well as lung and lymphoid tissue lesions in the challenge test. Compared to unvaccinated challenged animals, the vaccinated challenged animals showed significantly higher (p < 0.05) levels of anti-PCV2 IgG, PCV2d-specific interferon-γ (IFN-γ), and anti-MHP IgG. Conclusions: Based on clinical, microbiological, serological, and pathological assessments, this study confirmed that both combined vaccines could protect pigs against PCV2 infection caused by PCV2d. On the other hand, further research on the efficacy evaluation of these new vaccines against the MHP challenge and PCV2d/MHP co-challenge is needed.

• Reproductive and Developmental Biology
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• v.34 no.1
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• pp.1-6
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• 2010

Mesenchymal stem cells (MSCs) have the multipotent capacity and this potential can be applied for obtaining valuable cell types which can use for cell therapy on various regenerative diseases. However, insufficient availability of cellular source is the major problem in cell therapy field using adult stem cell sources. Recently, human embryonic stem cells (hESCs) have been highlighted to overcome a limitation of adult cellular sources because they retain unlimited proliferation capacity and pluripotency. To use of hESCs in cell therapy, above all, animal pathogen free culture system and purification of a specific target cell population to avoid teratoma formation are required. In this study, we describe the differentiation of a mesenchymal stem cell-like cells population from feeder-free cultured hESCs(hESC-MSCs) using direct induction system. hESC-MSCs revealed characteristics similar to MSCs derived from bone marrow, and undifferentiated cell markers were extremely low in hESC-MSCs in RT-PCR, immunostaining and FACS analyses. Thus, this study proffer a basis of effective generation of specialized human mesenchymal stem cell types which can use for further clinical applications, from xenofree cultured hESCs using direct induction system.

• Korean Journal of Poultry Science
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• v.28 no.2
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• pp.99-106
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• 2001

Pathologic changes and distribution of viral antigen as determined by immunohistochemistry were compared among 4-wk-old specific-pathogen free (SPF) chickens inoculated intratracheally with velogenic vis-cerotropic Newcastle disease virus isolated in Korea. Although the pattern of organ involvement and severity of lesion was different among chickens infected with different velogenic viscerotropic Newcastle disease (VVND) viruses, the pathological types of lesion was similar among the chickens. Severe lymphocytic necrosis and depletion were main histologic lesions in the immune related organs such as thymus, Fabricius bursa and spleen. The frequency of IP positive staining was variable depends on the types of tissues but not types of the kinds of VVND viruses infected. Brain, Fabricius bursa, thymus, cecal tonsil and trachea were IP positive with fairly high frequency and spleen, lung, proventriculus, intestine, pancreas, liver, kidney, heart and Harderian gland were with relatively low frequency. These results suggest that histologic evaluation and viral antigen specific immunohistochemical staining methods to determine virus distribution will be useful for pathogenic study of velogenic viscerotropic Newcastle disease virus infection in chicken.

• Journal of Microbiology and Biotechnology
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• v.18 no.3
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• pp.585-590
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• 2008

Human tropic Porcine Endogenous Retroviruses (PERVs) are the major concern in zoonosis for xenotransplantation because PERVs cannot be eliminated by specific pathogen-free breeding. Recently, a PERV A/C recombinant with PERV-C bearing PERV-A gp70 showed a higher infectivity (approximately 500-fold) to human cells than PERV-A. Additionally, the chance of recombination between PERVs and HERVs is frequently stated as another risk of xenografting. Overcoming zoonotic barriers in xenotransplantation is more complicated by recombination. To achieve successful xenotransplantation, studies on the recombination in PERVs are important. Here, we cloned and sequenced proviral PERV env sequences from pig gDNAs to analyze natural recombination. The envelope is the most important element in retroviruses as a pivotal determinant of host tropisms. As a result, a total of 164 PERV envelope genes were cloned from pigs (four conventional pigs and two miniature pigs). Distribution analysis and recombination analysis of PERVs were performed. Among them, five A/B recombinant clones were identified. Based on our analysis, we determined the minimum natural recombination frequency among PERVs to be 3%. Although a functional recombinant envelope clone was not found, our data evidently show that the recombination event among PERVs may occur naturally in pigs with a rather high possibility.

• Journal of International Academy of Physical Therapy Research
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• v.1 no.1
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• pp.10-18
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• 2010

This study was performed to investigate the effects of Needle Electrode Electrical Stimulation(NEES) on ischemia-induced cerebrovascular accidents. After obstruction and reperfusion of arteries in white mice, the amounts of necrosis and inflammation related substances Bax, IL-6, Caspase-3, and COX-2 were measured in neurons of the fore-brain. The following results were obtained. This study used 21 male specific pathogen free(SPF) SD rats, 8 weeks of age and approximately 300g in weight. Each exposed artery was completely occluded with non-absorbent suture thread and kept in that state for 5 minutes. The sutures were then removed to allow reperfusion of blood. Test group is control group(common carotid artery occlusion models), a GI(underwent common carotid artery occlusion), and NEES(underwent NEES after artery occlusion). The GI and NEES groups were given 12, 24, or 48 hours of reperfusion before NEES. NEES device(PG6, ITO, Japan, 9V, current, 2Hz) was used to stimulate the bilateral acupoint ST36 of the SD rats for 30 minutes while they were sedated with 3% isoflurane. An immuno-histochemistry test was done on the forebrains of the GI induced rats. Both Bax and Caspase-3 immuno-reactive cells, related to apoptosis, were greater in the GI than the NEES group. Cox-2 and IL-6 immuno-reactive cells, related to inflammation, were greater in the GI and NEES groups than the control group. We can expect that applying NEES after ischemic CVA is effective for preventing brain cells from being destroyed. And we can conclude NEES should be applyed on early stage of ischemic CVA.

• Journal of Veterinary Clinics
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• v.18 no.1
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• pp.55-60
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• 2001

Immunohistochemical and Electron Microscopical Studies on the Initial Skin Lesions Induced Experimentally by Very Virulent Strain of Marek\`s Disease Virus in Chickens Marek\`s disease virus (MDV), which is an avian herpesvirus, causes malignant CD3+CD4+CD8-T cell lymphomas at many sites including visceral organs, muscles, peripheral nerves and skin. In the early skin lesions induced by MDV, corelationship between the translational activity of MDV early gene, pp38 and demonstration of MDV particles in the lymphoid cells are not well studied. Therefore, skin biopsies taken at weekly intervals for 2 weeks from the same specific-pathogen free chicknes inoculated with Md/5 MDV were examined immunohistochemically and electron microscopically. In the skin biopsies sampled at 1 week and 2 weeks post inoculation (PI), feather follicle epithelium (FFE) exhibited usually strong positive reaction for pp38, whereas only few lymphoblasts, which were infiltrated around FFE revealed positive reaction. Electron microscopically, small lymphocytes were detectable in the dermis and subcutaneous skin tissues sampled at 1 week PI. The number of small lymphocytes was increased and pleomorphic lymphoblasts, which were medium to large in size were scattered among the small lymphocytes at 2 weeks PI. Some of lymphoblasts revealed degenerative and necrotic changes. FFE contained a lot of MDV particles in the nucleus including mature and immature ones. Infrequently, immature virus particles were observed not only in the degenerative and necrotic lymphoblasts, but also rarely in the health lymphoblasts. From the present results, spontaneous MDV activation including translational activity of MDV pp38 gene and formation of MDV particles was occurred in the lymphoblasts of early MD skin lesions.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.141-150
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• 1991

A local isolate of chicken anemia agent (CAA), isolate 89-69. was tested for pathogenicity for chickens. When chickens from a specific pathogen free (SPF) flock were inoculated intramuscularly with the isolate at one day old, all the chickens showed severe anemia at 14 to 18 days post inoculation(DPI) and returned to normal at 25DPI, Some of the inoculated chickens (27∼33％) died between 13 to 17 DPI's with lesions of severe aplasia of bone marrow and thymic atrophy. In chickens kept in contact with inoculated chickens, some of the chickens had anemia at 25 and 28 DPI's. Virus could be reisolated from inoculated as well as in contact chickens till 21 DPI. Antibodies to CAA could be detected in all inoculated and in contact chickens when tested at 42 DPI by the indirect fluorescent antibody method. When chickens from a different SPF flock were inoculated at one day old, degrees of anemia, both in frequency of incidence and severity, were low These chickens were proved partly to have antibodies to CAA when tested for hatchmates. In a survey for antibodies to CAA in field chicken flocks, one out of 7 flocks(14％) aged 3 to 10weeks was antibody positive whereas 19 out of 20 flocks(95％) over 20 weeks of age were positive. Altogether 29 out of 39 flocks (74％) were antibody positive.