• Korean Journal of Veterinary Service
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• v.46 no.3
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• pp.193-202
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• 2023

Porcine epidemic diarrhea is an infectious intestinal disease caused by the porcine epidemic diarrhea virus (PEDV). Especially, when suckling piglets are infected, the mortality rate is close to 100%. PEDV is classified into G1 and G2 types based on genetic differences. The G2 type PEDV outbreak in the United States in 2013 was highly pathogenic and contagious, and it has spread worldwide and caused continuous economic losses. Most commercial vaccines used are G1 type vaccines, and existing vaccines do not fully protect piglets due to genetic differences. In this study, we evaluated the safety of the newly developed G2 type attenuated HSGP vaccine strain by inoculating it into piglets and testing whether the vaccine virus spreads to the non-vaccinated, negative pigs and whether the vaccine reverts to its virulence during serial passage experiments. Each experiment lasted for 7 days for each passage, and fecal viral titers, clinical symptoms, and weight gain were measured daily. After the experiment, necropsy was performed to measure intestinal virus titer and pathological evaluation. As a result of the first passage, no transmission of the vaccine virus to negative pigs co-housed with vaccinated pigs was observed. In addition, after four consecutive passage experiments, the clinical symptoms and small intestine lesions were gradually alleviated, and no virus was detected in the feces in the fourth passage experiment. Therefore, it was concluded that the vaccine was safe without virulence reversion in accordance with the guidelines of the current licensing authority. However, further studies are needed on the genetic changes and biological characteristics of the mutant virus that occur during successive passages of the attenuated vaccine since the replication and clinical symptoms of the virus increased until the third passage during successive passages of the vaccine virus. Based on this study, it was concluded that virulence reversion and safety evaluation of attenuated vaccines through serial passage in target animals can be useful to evaluate the safety of attenuated viruses.

• Biomolecules & Therapeutics
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• v.30 no.2
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• pp.126-136
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• 2022

Liver fibrosis is part of the wound healing process to help the liver recover from the injuries caused by various liver-damaging insults. However, liver fibrosis often progresses to life-threatening cirrhosis and hepatocellular carcinoma. To overcome the limitations of current in vivo liver fibrosis models for studying the pathophysiology of liver fibrosis and establishing effective treatment strategies, we developed a new mouse model of liver fibrosis using polyhexamethylene guanidine phosphate (PHMG-p), a humidifier sterilizer known to induce lung fibrosis in humans. Male C57/BL6 mice were intraperitoneally injected with PHMG-p (0.03% and 0.1%) twice a week for 5 weeks. Subsequently, liver tissues were examined histologically and RNA-sequencing was performed to evaluate the expression of key genes and pathways affected by PHMG-p. PHMG-p injection resulted in body weight loss of ~15% and worsening of physical condition. Necropsy revealed diffuse fibrotic lesions in the liver with no effect on the lungs. Histology, collagen staining, immunohistochemistry for smooth muscle actin and collagen, and polymerase chain reaction analysis of fibrotic genes revealed that PHMG-p induced liver fibrosis in the peri-central, peri-portal, and capsule regions. RNA-sequencing revealed that PHMG-p affected several pathways associated with human liver fibrosis, especially with upregulation of lumican and IRAK3, and downregulation of GSTp1 and GSTp2, which are closely involved in liver fibrosis pathogenesis. Collectively we demonstrated that the PHMG-p-induced liver fibrosis model can be employed to study human liver fibrosis.

• Korean Journal of Veterinary Service
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• v.46 no.2
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• pp.161-165
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• 2023

A 6-year-old female long-tailed goral (Naemorhedus caudatus, goral) was admitted to the Gangwon wildlife medical rescue center due to severe starvation and hypothermia. The goral displayed clinical signs of severe weight loss, dehydration, lethargy, regurgitation, hypothermia, and bloating, with blood tests showing a decrease in albumin, calcium, glucose, and sodium. Supportive care was given through heating, oxygen supply, and fluid therapy, but the goral's condition worsened, and the goral died three days after admission. Radiographic and computed tomography scans revealed the presence of an indigestible foreign body (IFB) in the rumen, which was confirmed during the necropsy. The cause of goral's death was identified as chronic rumen impaction caused by the IFB (a ball of string), with other pathological findings including bloating, the presence of serous ascites, and congestion of digestive organs. Blood biochemical changes, clinical signs, and veterinary medical imaging diagnosis can be helpful in diagnosing ruminal impaction. This case report can provide valuable information for the diagnosis and treatment of ruminal impaction caused by IFB in endangered gorals, which may include rumenotomy or other surgical procedures.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.2
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• pp.117-123
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• 2018

The purpose of this report is to describe the diagnosed case of a large colonic impaction in an adult donkey. An adult female donkey (Equus africanus asinus; 6-years-old) was admitted to the Equine Hospital of Jeju Race Park with signs of anorexia, which had started 1 day previously. Clinical examination revealed: weak gut sounds, dehydration, and severe abdominal distension, but normal respiratory and heart rates and no signs of pain. Transrectal palpation identified an impaction in the colon. The patient was treated with nasogastric siphonage, fluid therapy, and nonsteroidal anti-inflammatory drugs. Over the course of a day, her condition worsened; she started trembling, could not stand, and 2 hours later she died. Upon necropsy, a vast amount of ingesta was found in the large colon, particularly in the left ventral colon. The cecum and small colon were normal. Eleven days prior to presentation, the stable management and diet of the donkey had changed. We suspect that the change of feed, reduced water consumption, and lack of exercise precipitated the illness. However, the exact cause of the sudden death of the donkey requires further investigation.

• Journal of Veterinary Science
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• v.24 no.5
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• pp.54.1-54.13
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• 2023

Background: Porcine reproductive and respiratory syndrome virus (PRRSV) vaccines do not provide full cross-protection, mainly due to the virus genetic variability. Despite this, vaccines based on modified-live PRRSV (PRRSV-MLV) reduce the disease impact. Objectives: To assess the efficacy of two commercial vaccines-one based on PRRSV1 (PRRSV1-MLV) and another on PRRSV2 (PRRSV2-MLV)-against a Japanese PRRSV2 field strain. Methods: Two groups of three-week-old piglets were vaccinated (G1: PRRSV1-MLV; G2: PRRSV2-MLV) and two were kept as non-vaccinated (INF and CTRL). One month later, G1, G2, and INF were challenged with a PRRSV2 field strain. Results: After the challenge, clinical signs were only observed in INF. Moreover, the highest rectal temperatures and values for the area under the curve (AUC) were observed in INF. Regarding viral detection, both AUC and the proportion of positive samples in blood were higher in INF. In G1, viremic animals never reached 100%. At necropsy (21 d after the challenge), differences for titers among groups were only found in tonsils (G1 < G2 and INF). One animal (belonging to G1) was negative in all tissues. Regarding humoral responses, G1 and G2 seroconverted after vaccination, as detected in the corresponding enzyme-linked immunosorbent assay. Specific neutralizing antibodies (NA) against PRRSV1-MLV were already detected at 14 d after vaccination in G1, showing a significant booster after the challenge, while PRRSV2-MLV NA were detected in G2 at the end of the experiment. Conclusions: Despite genetic differences, PRRSV1-MLV has been demonstrated to confer partial protection against a Japanese PRRSV2 strain, at least as good as PRRSV2-MLV.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.59-59
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• 2021

Stachys sieboldii Miq. (SSM) and Acorus gramineus Soland. (AGS) have been used as traditional medicines for thousands of years in parts of Asia, including Korea, China, and Japan. Recent researches on SSM and AGS have documented a wide spectrum of therapeutic properties, including anti-inflammatory, anti-oxidative, neurodegenerative disease effects. However, the toxicity and safety of SSM and AGS, and their mixture (medicinal herber mixture, MHMIX) were not confirmed. Therefore, this study was performed to evaluate the acute toxicity and safety of SSM, AGS and MHMIX. SSM, AGS and MHMIX were orally administered at a dose of 5,000 mg/kg in ICR mice. Animals were monitored for the mortality and changes in the body weight, clinical signs and gross observation during the 14 days after dosing, upon necropsy. We also measured parameters of organ weight, clinical chemistry, and hematology. No dead and no clinical signs were found during the experiment period after administration of a single oral dose of SSM, AGS and MHMIX. There were no adverse effects on clinical signs, body weight, or organ weight and no gross pathological findings in any treatment group. Therefore, LD50 value of SSM, AGS and MHMIX may be over 5,000 mg/kg and it may have no side toxic effect to ICR mice. The results on the single-dose toxicity of SSM, AGS and MHMIX indicate that it is not possible to reach oral dose levels related to death or dose levels with any harmful side effects.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2021.04a
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• pp.65-66
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• 2021

Glycyrrhiza species (Licorice) are one of the most commonly used medicinal plants in Asian countries such as China, India and Korea. It has been traditionally used to treat many disease including cough, cold, asthma, fatigue, gastritis and respiratory tract infections. Glycyrrhiza new variety, Wongam (WG), have been developed by Korea Rural Development Administration and revealed several pharmacological effects. However, limited data are available on the potential adverse effects of the WG. Here, we evaluated the general toxicity of the WG extract through single oral dose toxicity study in Sprague-Dawley rats. After single oral dose administration, there was no mortality up to 5000 mg/kg during experiment period. In addition, there was no clinical signs including body weight change, gross findings and necropsy findings up to 5000 mg/kg during experiment period. To conclude, the no-observed-adverse-effect level (NOAEL) of WG was higher than 5000 mg/kg and no target organs were identified in male and female Sprague-Dawley rats.

• Herbal Formula Science
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• v.31 no.4
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• pp.327-339
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• 2023

Objectives : This study conducted a repeated dose 90-day oral toxicity test in order to up-cycling Schisandra fruit extract powder(SFEP) using discarded Schisandra chinensis by-products and evaluated the NOAEL of SFEP. Methods : SD-rats were orally administered SFEP at concentrations of 0, 62.5, 125, and 250 mg/kg once daily for 90 days. Body weights and clinical signs were observed during the administration period. After completion of the experiment, the experimental animals were autopsied to observe necropsy findings and organ weights changes, and hematological parameters and blood chemistry values were measured. Results : During the SFEP administration period, clinical signs such as salivation, wounds, and erosion were sporadically observed in 1 to 2 animals. In the SFEP 250 mg/kg administered group, weights of the liver and thyroid gland significantly increased compared to the control group, but no significant changes were observed in organ weights according to body weights. As a result of measuring hematological parameters and blood chemistry values, a decrease in RDW, T-BIL, and TBA, and an increase in TP, ALB, and Ca were observed due to SFEP administration. However, these changes following SFEP administration were accidental and not dose-dependent. Additionally, no correlation was found between gender and other parameters. Conclusions : Therefore, the NOAEL of SFEP was confirmed to be 250 mg/kg.

• Parasites, Hosts and Diseases
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• v.62 no.1
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• pp.131-138
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• 2024

Halicephalobus gingivalis is a free-living nematode that occasionally causes infections in horses. We report a rare case of limb fracture of horse caused by infection with H. gingivalis. An 8-year-old mare was referred to the Veterinary Hospital of the Federal University of Lavras with claudication grade 5 of the right hind limb, that had been started 3 months ago. The patient had aseptic arthritis in the tarsal joint and edema that extended to the quartile. The radiographic examination showed punctate osteolysis with exacerbation of bone trabeculation along the calcaneus, talus, proximal epiphysis of the third metatarsal and distal epiphysis of the tibia. Treatment for arthritis was initiated, and the animal showed a slight improvement in limb function. However, 21 days after hospitalization, due to a comminuted fracture of the tibia, it was euthanized. At necropsy, yellowish masses were found from the metatarsal to the tibia, and around the tarsal bones and joint. Similar masses were also found in the left kidney. Numerous nematodes compatible with H. gingivalis were identified. This is the first description of a pathological fracture caused by H. gingivalis infection in an equine limb.

• Parasites, Hosts and Diseases
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• v.28 no.3
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• pp.183-194
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• 1990

In an attempt to develop prophylactic and therapeutic measures of the intestinal giant-cystic disease caused by Thelohanellus kitauei in the Israel carp, Cyprinus carpio nodus, pathological observations were conducted upon the carps which were hatched in May 1988 and raised in a net cage fish farm at the Soyang lake, managed by Horim Fisheries for the period of 21 months with 1~2 months interval. After a gross inspection of the carps, necropsy was carried out periodically in order to clarify the pathological changes in various internal organs and muscular tissues. Also. the prevalence of the disease was checked during the period from 1988 to 1990. Gross inspections revealed that the infected carps showed some degree of fading in body and gill color, back-emaciation symptoms, reddish anus accompanying erosion and relaxation and pot-belly, as well as discharge of yellowish white mucoid material from the anus. However, most carps died eventually of intestinal obstruction. Other significant necropsy fadings included cyst formation of various size in the intestinal mucosa, ascites, anemic condition through internal organs and muscular tissues, hyperemia and dilation of intestines with decreased tension, thinness and fragility, and full contents of semi-fluid or yellowish white mucoid material in the intestinal canals. Based on the morphological characteristics of the spores found in the cysts, parasitic location in the intestines, macro- and microscopic findings of the lesions, the parasites were identised as Thelohanellus kitauei Egusa os Nakajima, 1981. Although monthly changes of water temperature were distinct, the extrusion rates of the polar filaments of the spores stayed constant throughout the year with an exception of a lower rate in July, The lesions initiated from mucosa and submucosa in early July became large swellings and then complete mature (orms following the peracute course. From late August the upper cysts were gradually opened and most of the spores were dispersed from anus into the surrounding water through December but only a few lasted until next April. The cysts were completely recovered until next September. Comparing the incidence and prevalence of the disease by year tremendous infection and death rates were checked in the first prevalent year, 1988, but the rates were significantly decreased in the second year, and showed an almost normal status in the third year, 1990. As the above summarized results showed, the disease entity might come to an end in three years after the first prevalent year, however, the spores must be strictly prevented because they could be infective in the water for one year.