• IMMUNE NETWORK
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• v.14 no.6
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• pp.277-288
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• 2014

T cells are central players in the regulation of adaptive immunity and immune tolerance. In the periphery, T cell differentiation for maturation and effector function is regulated by a number of factors. Various factors such as antigens, co-stimulation signals, and cytokines regulate T cell differentiation into functionally specialized effector and regulatory T cells. Other factors such as nutrients, micronutrients, nuclear hormones and microbial products provide important environmental cues for T cell differentiation. A mounting body of evidence indicates that the microbial metabolites short-chain fatty acids (SCFAs) have profound effects on T cells and directly and indirectly regulate their differentiation. We review the current status of our understanding of SCFA functions in regulation of peripheral T cell activity and discuss their impact on tissue inflammation.

• Journal of Korean Neurosurgical Society
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• v.61 no.3
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• pp.302-311
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• 2018

Atypical teratoid rhabdoid tumours (ATRTs) are the most common malignant central nervous system tumours in children ${\leq}1year$ of age and represent approximately 1-2% of all pediatric brain tumours. ATRT is a primarily monogenic disease characterized by the bi-allelic loss of the SMARCB1 gene, which encodes the hSNF5 subunit of the SWI/SNF chromatin remodeling complex. Though conventional dose chemotherapy is not effective in most ATRT patients, high dose chemotherapy with autologous stem cell transplant, radiotherapy and/or intrathecal chemotherapy all show significant potential to improve patient survival. Recent epigenetic and transcriptional studies highlight three subgroups of ATRT, each with distinct clinical and molecular characteristics with corresponding therapeutic sensitivities, including epigenetic targeting, and inhibition of tyrosine kinases or growth/lineage specific pathways.

• IMMUNE NETWORK
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• v.7 no.4
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• pp.167-172
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• 2007

Various cell types that express regulatory function may influence the pathogenesis of most and perhaps all infections. Some regulatory cells are present at the time of infection whereas others are induced or activated in response to infection. The actual mechanisms by which different types of infections signal regulatory cell responses remain poorly understood. However a most likely mechanism is the creation of a microenvironment that permits the conversion of conventional T cells into cells with the same antigen specificity that have regulatory function. Some possible means by which this can occur are discussed. The relationship between regulatory cells and infections is complex especially with chronic situations. The outcome can either be of benefit to the host or damage the disease control process or in rare instances appears to be a component of a finely balanced relationship between the host and the infecting agent. Manipulating the regulatory cell responses to achieve a favorable outcome of infection remains an unfulfilled objective of therapeutic immunology.

• Proceedings of the Korean Society of Life Science Conference
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• 2007.10a
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• pp.23.1-23.1
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• 2007

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• Parasites, Hosts and Diseases
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• v.54 no.1
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• pp.15-20
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• 2016

Toxoplasmosis is an important zoonotic disease that can cause abortion in humans and animals. The aim of this study was isolation and subsequent genotyping of Toxoplasma gondii isolates in ovine aborted fetuses. During 2012-2013, 39 ovine aborted fetuses were collected from sheep flocks in Khorasan Razavi Province, Iran. The brain samples were screened for detection of the parasite DNA by nested PCR. The positive brain samples were bioassayed in Webster Swiss mice. The serum samples of mice were examined for T. gondii antibodies by IFAT at 6 weeks post inoculation, and T. gondii cysts were searched in brain tissue samples of seropositive mice. The positive samples were genotyped by using a PCR-RLFP method. Subsequently, GRA6 sequences of isolates were analyzed using a phylogenetic method. The results revealed that T. gondii DNA was detected in 54% (20/37, 95% CI 38.4-69.0%) brain samples of ovine aborted fetuses. In bioassay of mice, only 2 samples were virulent and the mice were killed at 30 days post inoculation, while the others were non-virulent to mice. The size of cysts ranged $7-22{\mu}m$. Complete genotyping data for GRA6 locus were observed in 5 of the 20 samples. PCR-RLFP results and phylogenetic analysis revealed that all of the isolated samples were closely related to type I. For the first time, we could genotype and report T. gondii isolates from ovine aborted fetuses in Khorasan Razavi Province, Iran. The results indicate that the T. gondii isolates are genetically related to type I, although most of them were non-virulent for mice.

• Journal of Korean Neurosurgical Society
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• v.50 no.6
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• pp.481-485
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• 2011

Objective : The purpose of this study is to investigate serial changes of hypoxia-inducible factor $1{\alpha}$ (HIF-$1{\alpha}$), as a key regulator of hypoxic ischemia, and apoptosis of hippocampus induced by bilateral carotid arteries occlusion (BCAO) in rats. Methods : Adult male Wistar rats were subjected to the permanent BCAO. The time points studied were 1, 2, 4, 8, and 12 weeks after occlusions, with n=6 animals subjected to BCAO, and n=2 to sham operation at each time point, and brains were fixed by intracardiac perfusion fixation with 4% neutral-buffered praraformaldehyde for brain section preparation. Immunohistochemistry (IHC), western blot and terminal uridine deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay were performed to evaluate HIF-$1{\alpha}$ expression and apoptosis. Results : In IHC and western blot, HIF-$1{\alpha}$ levels were found to reach the peak at the 2nd week in the hippocampus, while apoptotic neurons, in TUNEL assay, were maximal at the 4th week in the hippocampus, especially in the cornu ammonis 1 (CA1) region. HIF-$1{\alpha}$ levels and apoptosis were found to fluctuate during the time course. Conclusion : This study showed that BCAO induces acute ischemic responses for about 4 weeks then chronic ischemia in the hippocampus. These in vivo data are the first to show the temporal sequence of apoptosis and HIF-$1{\alpha}$ expression.

• Parasites, Hosts and Diseases
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• v.49 no.3
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• pp.213-219
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• 2011

This experiment was conducted to assess the changing patterns and relative values of acute phase proteins and inflammatory cytokines in experimental caprine coccidiosis. Eighteen newborn kids were allocated to 3 equal groups. Two groups, A and B, were inoculated with a single dose of $1{\times}10^3$ and$1{\times}10^5$sporulated oocysts of Eimeria arloingi, respectively. The third group, C, received distilled water as the control. Blood samples were collected from the jugular vein of each kid in both groups before inoculation and at days 7, 14, 21, 28, 35, and 42 post-inoculation (PI), and the levels of haptoglobin (Hp), serum amyloid A (SAA), TNF-${\alpha}$, and IFN-${\gamma}$ were measured. For histopathological examinations, 2 kids were selected from each group, euthanized, and necropsied on day 42 PI. Mean Hp concentrations in groups A and B (0.34 and 0.68 g/L) at day 7 PI were 3.2 and 6.3 times higher than the levels before inoculation. The mean SAA concentrations in groups A and B (25.6 and 83.5 ${\mu}g$/ml) at day 7 PI were 4.2 and 13.7 times higher than the levels before inoculation. The magnitude and duration of the Hp and SAA responses correlated well with the inoculation doses and the severity of the clinical signs and diarrhea in kids. These results were consistent with the histopathological features, which showed advanced widespread lesions in group B. In both groups, significant correlations were observed for TNF-${\alpha}$ and IFN-${\gamma}$ with SAA and Hp, respectively. In conclusion, Hp and SAA can be useful non-specific diagnostic indicators in caprine coccidiosis.

• Korean Journal of Veterinary Research
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• v.38 no.4
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• pp.909-917
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• 1998

Six different sequences types(A through E and H) and a subtype(Bl) of the small subunit ribosomal RNA(SSUrRNA) gene were found in bovine Theileria isolates from different areas of Korea and Japan. The sequences were aligned and three hypervariable regions were observed in the nucleotide position ranges 212~231, 261~270 and 632~690. Five of the Theileria isolates yielded sequence type A; these were the field isolates KCB, KCN, and KCJ, and the laboratory stock KLS, all from Korea, and a single isolate from Japan (JHS). This sequence type is identical to the SSUrRNA gene sequence listed for Theileria buffeli (GenBank Accession No. Z15106) from Marula, Kenya. The Korean field isolate KKB yielded only a single sequence type (B), but multiple sequence types were found in some isolates. For example, KCB and JHS isolates yielded both types A and B ; isolate KKW showed types B and H; isolate KCN showed types A, C, and D ; and isolate KCJ showed types A, B, E, and a subtype B1. Finding of the multiple sequences SSUrRNA gene sequences suggests that bovine Theileria isolates from both Korea and Japan may consist of mixed populations.

• Proceedings of the Korean Society of Veterinary Clinics Conference
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• 2009.04a
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• pp.228-228
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• 2009

• Toxicological Research
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• v.17
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• pp.263-270
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• 2001

The carcinogenic potential of steviol, a metabolite of/ stevioside (a compound that is used as a sweetener for food and drink), was examined in hamsters of both sexes. Groups of 55 male and 55 female hamsters were given diets containing steviol at 0, 100 and 500 mg/kg diet for 22 months in males and 18 months in females. After 6, 12 and 22 months in males and 18 months in females. hamsters from each group were sacrificed for hematological and biochemical tests. Growth food utilization and consumption, general appearance and mortality were similar in treated and control groups. The mean life span of hamsters given steviol was not significantly different from that of the controls. No treatment-related changes were observed in hematological, urinary and biochemical values at any stage of the study. There was no significantly altered development of neoplastic or non-neoplastic lesions attributable to steviol treatment in any organ or tissue. The highest level oj steviol in the diet which still causes no effects in hamsters was 500 mg/kg diet, under the experimental conditions used.