• Korean Journal of Veterinary Service
• /
• v.39 no.4
• /
• pp.211-219
• /
• 2016

For determining the prevalence of major enteric pathogens, clinical examination and etiological diagnosis were carried out on 75 Korean pig farms. Enteric disease-suspected signs were observed in 90.7% of the farms and the incidence and severity were higher in younger age groups of the pigs. Five of seven pathogens were detected in 375 fecal samples collected from the 75 farms, and the farm-level prevalence of porcine rotavirus group A (PoRVA), pathogenic Escherichia (E.) coli, Lawsonia (L.) intracelluraris, Salmonella spp., and Brachyspira (B.) hyodysenteriae was 54.7%, 54.7%, 16.0%, 10.7% and 2.7%, respectively. PoRVA was extensively infected in suckling and weaning pig groups. The prevalence of pathogenic E. coli was highest in suckling period, and after the period, it exhibited a tendency to decrease. Salmonella spp. and L. intracelluraris were detected in all feeding groups of pigs in a ratio of 1.3~6.7%. B. hyodysenteriae was detected in 1.3~2.7% of growing and fattening pig groups but not detected in suckling and weaning pig groups. At least one or more pathogens were detected in 30.1% of 375 fecal samples. Among these, 25.0% or 5.1% of cases were single or mixed infection. Enteric disease signs of the pigs were significantly co-related with the detection of PoRVA, pathogenic E. coli or Salmonella spp. (P<0.01) but not with L. intracelluraris or B. hyodysenteriae (P>0.05). Conclusively, it will be expected that these data obtained in this study are very useful for subsequent studies and prevention strategies for swine enteric disease in Korean pig farms.

• Parasites, Hosts and Diseases
• /
• v.25 no.1
• /
• pp.1-6
• /
• 1987

This study was to observe the changes of blastogenic responses of splenic Iymphocytes to T-cell mitogens, N. fcwleri Iysate and concanaualin A, and serum antibody titer during the course of experimental PAM in mice. Naegleria fcwleri, strain 0359, was cultured in the CGVS medium axenically and inoculated intranasally with $7{\times}10^4$ trophozoites for the development of experimental PAM in mice. The amoebae were subjected to ultrasonication and centrifuged at 20,000g for 60 minutes, and filtered through $0.2{\mu\textrm{m}}$ filter membrane. The supernatant, N. fcwleri Iysate, was used as T-cell mitogen, and antigen for ELISA. The serum antibody was examined by ELISA using peroxidase conjugate. Two hundred ${\mi}l$ of $10^6$ splenocytes in RPMI 1640 containing 0% fetal calf serum were added to each well of a microtiter plate. To each well was added T-cell mitogens, $100{\mu}g/ml$ of N. fowleri Iysate or $4{\mu}g/ml$ of con. A, and the plates were incubated for 42 hours at $37^{\circ}C$ in 5% $CO_2$ incubator. Cultures were pulsed with of $methyl-(^3H)-thymidine$ 6 hour before harvesting. The mean blastogenic response of the splenocytes to N. fewleri Iysate was reduced, whereas that to con. A was also reduced up to on day 11 after infection. Both of these results were statistically significant compared with those of uninfected control group. The serum antibody titers were increased gradually up to day 15. The results indicated that there was an impairment of the blastogenic response of splenocytes to N. fowleri Iysate during the acute course of experimental PAM in mice.

• Parasites, Hosts and Diseases
• /
• v.32 no.3
• /
• pp.185-194
• /
• 1994

The present study was undertaken to assess the role of cytokines in the activation of peritoneal macrophages from Toxoplasma-infected mice. Peritoneal macrophages from Toxoplasma-infected mice (10 cysts of Beverley strain/mouse) were harvested 8 weeks after infection, and incubated with the mitogen-induced lymphokine, recombinant mouse $interferon-{\gamma}(IFN-{\gamma})$, recombinant mouse tumor necrosis $factor-{\alpha}{\;}(TNF-{\alpha})$ alone or in combination with 4$IFN-{\gamma}(IFN-{\gamma}/TNF-{\alpha})$ for 24hr at 37^{\circ}C$, 5% $CO_2$. Macrophage activation was measured by the amount of $H_20_2{\;}and{\;}N0_2^{-}$ production, and antiToxoplasma activities of macrophages. $IFN-{\gamma}{\;}or{\;}IFN-{\gamma}/TNF-{\alpha}-treated$ macrophages from Toxoplasma-infected mice revealed significantly higher $H_20_2$ production than resident macrophages from Toxoplasma-infected mice. The production of $N0_2^{-}{\;}by{\;}TNF-{\alpha}-,{\;}IFN-{\gamma}-{\;}or{\;}IFN-{\gamma}/TNF-{\alpha}-treated$ macrophages from Toxoplasma-infected mice were significantly higher than that by resident macrophages, whereas lymphokine-treated group produced similar amount as that produced by resident macrophages. Anti-Toxoplasma activities of cytokinetreated macrophages from Toxoplasma-infected mice were Significantly higher than those of resident macrophages. $IFN-{\gamma}-treated$ macrophages were significantly increased production of $H_20_2{\;}and{\;}N0_2^{-}$, and anti-Toxoplasma activities of macrophages between normal and Toxoplasma-infected mice, whereas the other cytokine-treated groups were not significant differences between them. These data suggested that IFN-{\gamma}was the only one of cytokines capable of significantly activating the peritoneal macrophages from Toxoplasmainfected mice.

• Polymer(Korea)
• /
• v.34 no.4
• /
• pp.363-368
• /
• 2010

Adequate acidic environment in wound healing prevents the inflammation of virus, increases the cell activity, promotes cell proliferation and regular rearrangement of fibroblast, and results in matured epithelialization. In this study, we prepared dressing materials consisting of pectin and carboxymethylcellulose (CMC) with varied ratios. These dressing materials showed different pH values according to the composition ratio. The effect of acidity of pectin/CMC dressing materials on wound healing rates, degree of epithelialization, collagen deposition, and so on, in 3 types of wound models (fresh surgical wounds, $3^{rd}$ degree burn wounds, and infection wounds) were investigated by animal tests. From the results of wound contraction, wound healing, and epithelialization, it can be deduced that dressing material having pectin/CMC ratio of 16/19 (pH 4.67) is most effective among the 3 types of wound models.

• Journal of Veterinary Science
• /
• v.22 no.6
• /
• pp.41.1-41.14
• /
• 2021

Background: Our previously prepared ceftiofur (CEF) hydrochloride oily suspension shows potential wide applications for controlling swine Streptococcus suis infections, while the irrational dose has not been formulated. Objectives: The rational dose regimens of CEF oily suspension against S. suis were systematically studied using a pharmacokinetic-pharmacodynamic model method. Methods: The healthy and infected pigs were intramuscularly administered CEF hydrochloride oily suspension at a single dose of 5 mg/kg, and then the plasma and pulmonary epithelial lining fluid (PELF) were collected at different times. The minimum inhibitory concentration (MIC), minimal bactericidal concentration, mutant prevention concentration (MPC), post-antibiotic effect (PAE), and time-killing curves were determined. Subsequently, the area under the curve by the MIC (AUC_0-24h/MIC) values of desfuroylceftiofur (DFC) in the PELF was obtained by integrating in vivo pharmacokinetic data of the infected pigs and ex vivo pharmacodynamic data using the sigmoid E_max (Hill) equation. The dose was calculated based on the AUC_0-24h/MIC values for bacteriostatic action, bactericidal action, and bacterial elimination. Results: The peak concentration, the area under the concentration-time curve, and the time to peak for PELF's DFC were 24.76 ± 0.92 ㎍/mL, 811.99 ± 54.70 ㎍·h/mL, and 8.00 h in healthy pigs, and 33.04 ± 0.99 ㎍/mL, 735.85 ± 26.20 ㎍·h/mL, and 8.00 h in infected pigs, respectively. The MIC of PELF's DFC against S. suis strain was 0.25 ㎍/mL. There was strong concentration-dependent activity as determined by MPC, PAE, and the time-killing curves. The AUC_0-24h/MIC values of PELF's DFC for bacteriostatic activity, bactericidal activity, and virtual eradication of bacteria were 6.54 h, 9.69 h, and 11.49 h, respectively. Thus, a dosage regimen of 1.94 mg/kg every 72 h could be sufficient to reach bactericidal activity. Conclusions: A rational dosage regimen was recommended, and it could assist in increasing the treatment effectiveness of CEF hydrochloride oily suspension against S. Suis infections.

• Korean Journal of Psychosomatic Medicine
• /
• v.30 no.2
• /
• pp.145-154
• /
• 2022

Objectives : This study intends to assess the associations among perceived stigma at the time of infection, coping strategies adopted 12 months later and depressive and posttraumatic symptoms 24 months later in Middle Eastern Respiratory Syndrome (MERS) survivors. Methods : A nationwide cohort study was conducted on 63 survivors of 2015 MERS outbreak. Demographic data, illness severity of MERS, depression and posttraumatic stress symptoms, coping strategies and MERS-related stigma were collected 12 and 24 months after the MERS outbreak, respectively. Results : Higher levels of perceived stigma at the time of outbreak were associated with higher levels of dysfunctional coping strategies after 12 months (p=0.003) and more severe depressive (p=0.058) and posttraumatic stress symptoms (p=0.011) after 24 months. Moreover, higher levels of dysfunctional coping strategies after 12 months were significantly associated with more severe depressive (p=0.002) and posttraumatic stress symptoms (p<0.001) after 24 months. Conclusions : Social stigma against people who have contracted an emerging infectious disease can leave a negative impact on the mental health of the survivors in the long term. In case of novel pandemics in the future, prompt rectification of stigma and promotion of adaptive coping strategies in survivors are needed.

• Journal of Veterinary Science
• /
• v.21 no.5
• /
• pp.80.1-80.13
• /
• 2020

Background: In suckling piglets, transmissible gastroenteritis virus (TGEV) causes lethal diarrhea accompanied by high infection and mortality rates, leading to considerable economic losses. This study explored methods of preventing or inhibiting their production. Bovine antimicrobial peptide-13 (APB-13) has antibacterial, antiviral, and immune functions. Objectives: This study analyzed the efficacy of APB-13 against TGEV through in vivo and in vitro experiments. Methods: The effects of APB-13 toxicity and virus inhibition rate on swine testicular (ST) cells were detected using 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyl tetrazolium bromide (MTT). The impact of APB-13 on virus replication was examined through the 50% tissue culture infective dose (TCID₅₀). The mRNA and protein levels were investigated by real-time quantitative polymerase chain reaction and western blot (WB). Tissue sections were used to detect intestinal morphological development. Results: The safe and effective concentration range of APB-13 on ST cells ranged from 0 to 62.5 ㎍/mL, and the highest viral inhibitory rate of APB-13 was 74.1%. The log₁₀TCID₅₀ of 62.5 ㎍/mL APB-13 was 3.63 lower than that of the virus control. The mRNA and protein expression at 62.5 ㎍/mL APB-13 was significantly lower than that of the virus control at 24 hpi. Piglets in the APB-13 group showed significantly lower viral shedding than that in the virus control group, and the pathological tissue sections of the jejunum morphology revealed significant differences between the groups. Conclusions: APB-13 exhibited good antiviral effects on TGEV in vivo and in vitro.

• Journal of Animal Science and Technology
• /
• v.64 no.1
• /
• pp.166-182
• /
• 2022

Deer antler velvet is widely used in traditional medicine for its anti-aging, antioxidant, and immunity-enhancing effects. However, few studies have reported on the discovery of probiotic strains for deer antler fermentation to increase functional ingredient absorption. This study evaluated the ability of probiotic lactic acid bacteria to enhance the concentrations of bioactive molecules (e.g., sialic acid and gamma-aminobutyric acid [GABA]) in extracts of deer antler velvet. Seventeen strains of Lactobacillus spp. that were isolated from kimchi and infant feces, including L. sakei, L. rhamnosus, L. brevis, and L. plantarum, and those that improved the life span of Caenorhabditis elegans were selected for evaluation. Of the 17 strains, 2 (L. rhamnosus LFR20-004 and L. sakei LFR20-007) were selected based on data showing that these strains increased both the sialic acid and GABA contents of deer antler extract after fermentation for 2 d and significantly improved the life span of C. elegans. Co-fermentation with both strains further increased the concentrations of sialic acid, GABA, and metabolites such as short-chain fatty acids and amino acids. We evaluated the biological effects of the fermented antler velvet (FAV) on the antibacterial immune response in C. elegans by assessing worm survival after pathogen infection. The survival of the C. elegans conditioned with FAV for 24h was significantly higher compared with that of the control worm group fed only normal feed (non-pathogenic E. coli OP50) exposed to E. coli O157:H7, Salmonella typhi, and Listeria monocytogenes. To evaluate the protective effects of FAV on immune response, cyclophosphamide (Cy), an immune-suppressing agent was treated to in vitro and in vivo. We found that FAV significantly restored viability of mice splenocytes and immune promoting-related cytokines (interleukin [IL]-6, IL-10, inducible nitric oxide synthase [iNOS], interferon [IFN]-γ, and tumor necrosis factor [TNF]-α) were activated compared to non-fermented deer antlers. This finding indicated the protective effect of FAV against Cy-induced cell death and immunosuppressed mice. Taken together, our study suggests that immune-promoting antler velvet can be produced through fermentation using L. rhamnosus LFR20-004 and L. sakei LFR20-007.

• Pediatric Infection and Vaccine
• /
• v.28 no.3
• /
• pp.173-180
• /
• 2021

After initial reports of multisystem inflammatory syndrome in children (MIS-C) in April 2020 in Europe, this disease has been known to occur in children with recent history of coronavirus disease 2019 (COVID-19) and most cases have been reported in Europe and the Unites States of America. We report a case of a 14-year-old girl who was diagnosed with MIS-C with acute myocarditis and successfully treated with intravenous immunoglobulin (IVIG), methylprednisolone, and anakinra. At initial presentation, she had persistent high fever, generalized rash, generalized swelling, abdominal pain, and low blood pressure. She showed a remarkably elevated level of inflammation and cardiac enzyme markers and had a previous history of COVID-19 5 weeks before the initial presentation. After extensive work up, other infectious and non-infectious causes were excluded. She was diagnosed with MIS-C and initially treated with IVIG and high-dose methylprednisolone; however, despite treatment, her heart function deteriorated and coronary artery dilatation progressed. Therefore, anakinra, an interleukin-1 receptor antagonist, was administered on hospital day 6, after which her cardiac function exhibited improvement. She was discharged on hospital day 19 without any symptoms, and follow-up echocardiography after 1 month revealed fully recovered heart function with normal coronary arteries.

• Journal of Life Science
• /
• v.33 no.8
• /
• pp.612-622
• /
• 2023

T-cell deficiency may occur in various clinical conditions including congenital defects, cell/organ transplantation, HIV infection and aging. In this regard, the development of artificial thymus has recently been attracting much attention. To achieve this aim, the development of techniques for 3D culture of thymic stromal cells is necessary because thymocytes grown only in a 3D thymic microenvironment can be differentiated fully to become mature, immunocompetent T cells; the same cannot be achieved for thymocytes grown in 2D. This study aimed to develop a nanotechnology-based 3D culture technique using polymeric scaffolds for thymic epithelial cells (TECs), the main component of thymic stromal cells. Scanning electron microscopic observation revealed that the pores of both PCL and PCL/PLGA scaffolds were filled with TECs. Interestingly, TECs grown in 3D on polydopamine-coated scaffolds exhibited enhanced cell attachment and proliferation compared to those grown on non-coated scaffolds. In addition, the gene expression of thymopoietic factors was upregulated in TECs cultured in 3D on polydopamine-coated scaffolds compared to those cultured in 2D. Taken together, the results of the present study demonstrate an efficient 3D culture model for TECs using polymeric scaffolds and provide new insights into a novel platform technology that can be applied to develop functional, biocompatible scaffolds for the 3D culture of thymocytes. This will eventually shed light on techniques for the in vitro development of T cells as well as the synthesis of artificial thymus.