• Journal of Veterinary Science
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• 제19권6호
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• pp.750-758
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• 2018

Influenza virus infection is a zoonosis that has great socioeconomic effects worldwide. Influenza infection induces respiratory symptoms, while the influenza virus can infect brain and leave central nervous system sequelae. As children are more vulnerable to infection, they are at risk of long-term neurological effects once their brains are infected. We previously demonstrated that functional changes in hippocampal neurons were observed in mice recovered from neonatal influenza infection. In this study, we investigated changes in myelination properties that could affect neural dysfunction. Mice were infected with the influenza virus on postnatal day 5. Tissues were harvested from recovered mice 21-days post-infection. The expression levels for myelin basic protein (MBP) were determined, and immunohistochemical staining and transmission electron microscopy were performed. Real-time polymerase chain reaction and Western blot analyses showed that mRNA and protein expressions increased in the hippocampus and cerebellum of recovered mice. Increased MBP-staining signal was observed in the recovered mouse brain. By calculating the relative thickness of myelin sheath in relation to nerve fiber diameter (G-ratio) from electron photomicrographs, an increased G-ratio was observed in both the hippocampus and cerebellum of recovered mice. Influenza infection in oligodendrocyte-enriched primary brain cell cultures showed that proinflammatory cytokines may induce MBP upregulation. These results suggested that increased MBP expression could be a compensatory change related to hypomyelination, which may underlie neural dysfunction in recovered mice. In summary, the present results demonstrate that influenza infection during the neonatal period affects myelination and further induces functional changes in influenza-recovered mouse brain.

• 한국동물위생학회지
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• 제36권2호
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• pp.67-71
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• 2013

Neonatal infection caused by Cronobacter species can result in serious illnesses such as bacteremia, septicemia, meningitis, and death in at-risk infants who are orally fed contaminated reconstituted powdered infant formulas. The objective of this study was to compare the virulence among three Cronobacter species strains by using an animal model for human neonatal Cronobacter species infections. We acquired timed-pregnant ICR mice and all owed them to give birth naturally. On postnatal day 3, each pup was administered orally a total dose of $1{\times}10^7$ CFU Cronobacter species strain 3439, CDC 1123-79, and 3231. Mice were observed twice daily for morbidity and mortality. At postnatal day 10, the remaining pups were euthanized, and brain, liver, and cecum were excised and analyzed for the presence of Cronobacter species. Cronobacter species were isolated from cecum and other tissues in inoculated mice. In the tissues of Cronobacter species infected mice, meningitis and gliosis were detected in the brain. In this study, we identified the virulence among Cronobacter species strains by using a neonatal mice model which was a very effective animal model for human neonatal Cronobacter species infections.

• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.63-63
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• 2003

In an effort to uncover the spermatogenic impairment by the polychlorinated biphenyls (PCBs), the expression of tight junctions (TJs) genes important for the formation of the blood testis barrier (BTB) were examined following the 3,3',4,4',5-pentachloro biphenyl (PCB126) treatment in cultured neonatal testis in mice. At 4 days (D4) after 10 and 100 nM PCB126 treatment the expression of claudin-11 was significantly increased when compared with vehicle control. In contrast no difference in occludin and claudin-1 expression was found among the experimental group. On D8, 100 nM PCB126 significantly increased the expression of claudin-11 but not occludin and claudin-1. 1 uM PCB126 treatment significantly decreased expressions of occludin and ciaudin -1, suggesting the general toxic effect on the Sertoli cell. Because PCB126 does not alter the proliferative activity of spermatogenic cells and Sertoli cells in neonatal testis, it is likely that increase in the expression of claudin-11 by low dose of PCB126 may attribute to the alteration of the Sertoli cells differentiation in testis. It also emphasized that PCB126 might have differentially affected the transcription of TJ genes in Sertoli cells. In conclusion, this result suggests that the structure of TJ may be targeted by PCB126 in neonatal testis in mice and that co-PCB is potentially harmful to spermatogenesis by alteration of the development of BTB.

• International Journal of Oral Biology
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• 제32권1호
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• pp.13-22
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• 2007

The stem cell research is emerging as a cutting edge topic for a new treatment for many chronic diseases. Recently, dental stem cell would be possible for regeneration of tooth itself as well as periodontal tissue. However, the study of the cell characterization is scarce. Therefore, we performed the genetic profiling and the characterization of mouse fetus/neonate derived dental tissue and cell to find the identification during dental development. We separated dental arch from mandibles of 14.5 d fetal mice and neonate 0 d under the stereoscope, and isolated dental cells primarily from the tissues. Then, we examined morphology and the gene expression profiles of the primary cells and dental tissues from fetus/neonate and adult with RT-PCR. Primary dental cells showed heterogeneous but the majority was shown as fibroblast-like morphology. The change of population doubling time levels (PDLs) showed that the primary dental cells have growth potential and could be expanded under our culture conditions without reduction of growth rate. Immunocytochemical and flow cytometric analyses were performed to characterize the primary dental cell populations from both of fetus (E14.5) and neonate. Alpha smooth muscle actin (${\alpha}-SMA$), vimentin, and von Willebrand factor showed strong expression, but desmin positive cells were not detected in the primary dental cells. Most of the markers were not uniformly expressed, but found in subsets of cells, indicating that the primary dental cell population is heterogeneous, and characteristics of the populations were changed during culture period. And mesenchymal stem cell markers were highly expressed. Gene expression profile showed Wnt family and its related signaling molecules, growth factors, transcription factors and tooth specific molecules were expressed both fetal and neonatal tissue. The tooth specific genes (enamelin, amelogenin, and DSPP) only expressed in neonate and adult stage. These expression patterns appeared same as primary fetal and neonatal cells. In this study we isolated primary cells from whole mandible of fetal and neonatal mice. And we investigated the characteristics of the primary cells and the profile of gene expressions, which are involved in epithelial-mesenchymal interactions during tooth development. Taken together, the primary dental cells in early passages or fetal and neonatal mandibles could be useful stem cell resources.

• Animal cells and systems
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• 제3권3호
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• pp.319-329
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• 1999

Onset of female puberty follows a series of prepubertal cellular and molecular events including changes of synaptic plasticity, synthetic and releasing activity and gene expression. Dramatic increase of gonadal steroid level is one of the most prominent changes before the onset of puberty. Based on the importance of steroid feedback upon the hypothalamus, we adopted an estrogen sterilized rat (ESR) model where 100 ng of 17$\eta$-estradiol were administered into neonatal pubs for 7 days after birth. To identify genes involved in the onset of female puberty, we applied PCR differential display using RNA samples derived from ESR and control rat hypothalami. About 100 out of more than 1000 RNA species examined displayed differential expression patterns between a 60-day old control rat and ESR. Sequence analysis of differentially amplified PCR products showed homology with genes such as mouse kinesin superfamily-associated protein 3 (KAP3) and several cDNAs previously described by others in mouse and human tissues. Several gene products such as 2-1 and 8-1 corresponded to novel DNA sequences. We analyzed mRNA levels of KAP3, 2-1 and 8-1 genes in the hypothalami derived from neonatal, 6-, 28-, 31-, and 40-day old rats. Northern blot analysis showed that mRNAs of KAP3, 2-1 and 8-1 genes were markedly increased before the initiation of puberty. Neonatal treatment of estrogen clearly inhibited prepubertal increases in KAP3, 2-1 and 8-1 mRNA levels. Therefore, these genes may play important roles in the initiation of hypothalamic puberty. In addition, intracerebroventricular (icv) injection of antisense KAP3 oligodeoxynucleotide (ODN) clearly delayed puberty initiation determined by vaginal opening, which further confirmed that KAP3 plays an important role in the regulation of puberty initiation.

• 동의생리병리학회지
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• 제17권2호
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• pp.447-450
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• 2003

To clerify the cytotoxicity of reactive oxygen species in cultured hippocampal neurons of neonatal mouse, toxic effect was measured by MTT assay after cultured cells were incubated for 3 hours in the media containing 1～40 μM concentrations of H₂O₂. In addition, the protective effect of vitamin E was determined in these cultrures. Cell viability was significantly decreased in a dose-dependent manner after exposure of 10 μM H₂O₂ to cultured mouse hippocampal neurons for 5 hours. In the protective effect of vitamin E, vitamin E prevented the H₂O₂-induced cytotoxicity in these cultures. From these results, it suggests that H₂O₂ has toxic effect in cultured mouse hippocampal neurons and vitamin E has protective effect on the cytotoxicity induced by H₂O₂.

• 치위생과학회지
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• 제20권2호
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• pp.74-81
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• 2020

Background: In the early stages of development, teeth and lingual papillae are induced and developed through special and complex epithelial-mesenchymal interactions. Tooth completion indicates the beginning of the weaning phase, and accordingly, many oral tissues and organs are completed, and it is thought that their developmental completion times are related to each other. The purpose of this study was to clarify the embryonic and neonatal development of the filiform papillae and mandibular molar tooth, and discuss the developmental relationship between these organs by comparing the developmental completion times. Methods: Embryos at embryonic day 15 (EM15), 17 (EM17), and 21 (EM21) and mice at neonatal day 1 (NE1), 5 (NE5), 10 (NE10), and 21 (NE21) were used for experimentation. Tissues dissected from embryos and mice were fixed, and processed for histological analysis. Sections from the tissues were stained with hematoxylin and eosin for observation under a light microscope. Results: Based on the histological analysis results, the developmental process of the lingual epithelium covering the dorsal surface of the tongue was classified into three stages: initiation, morphogenesis, and functional. The development of the filiform papillae begins at EM17; undergoes rapid morphological changes in epithelial cells at EM21, PN1 and PN5, and reaches the functional stage at PN10, which is the sucking phase. Tooth development begins at EM13 or 15 and is completed at NE21 through prenatal and postnatal development. Conclusion: The development of the filiform papillae was initiated late and completed quickly through embryonic and neonatal development in comparison with the mandibular molar tooth. The filiform papillae are considered to play an important role in sucking rather than mastication as it is completed in the sucking phase.

• 동의생리병리학회지
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• 제17권2호
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• pp.457-460
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• 2003

It has been suggested that oxidative stress of reactive oxygen species(ROS) may play an important role in the pathogenesis of neurological disorder. The aim of this study was to elucidate the oxidative stress of glucose oxidase(GO) in the cultured mouse spinal motor neurons and the preventing effect of Benincasae Semen(BS) on ROS-induced neurotoxicity. Cytotoxic effect of GO and protective effect of BS were performed by MTT assay. 30mU/ml GO decreased cell viability in dose-and time-dependent mannner, and BS diminished GO-induced neurotoxicity in these cultures. From above the results, ROS such as GO has toxic effect, and herb extract of BS is very effective against GO-induced neurotoxicity in cultured spinal motor neurons of neonatal mouse.

• 대한한방소아과학회지
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• 제35권4호
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• pp.96-111
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• 2021

Objectives The purpose of this study is to look for pathological mechanism of disease development caused by Taedok, by studying whether stress and diet in pregnant ICR mice affect the intestinal flora and IgA (Immunoglobulin A) concentration. Methods The mice were divided into 4 groups (n=5 per group) based on the concept of Taedok: the control group (G1), stress group (G2), capsaicin diet group (G3), high fat diet group (G4). We collected and analyzed intestinal flora from maternal feces and cecal flora from neonatal mice by group. Then, IgA concentration in the maternal feces and sIgA (secretory Immunoglobulin A) concentration in the cecal contents of newborn mice were analyzed. In addition, serum corticosterone was analyzed before and after stress application. Results Changes in maternal intestinal flora and neonatal mice cecal flora by stress and diet were observed. There were no significant changes in the IgA concentration in maternal feces and the sIgA concentration in the cecal contents of neonatal mice. No significant changes compared to the control group were observed between groups before and after applying stress. However, when comparing within one subject, a significant increase was confirmed after stress application in the stress group (G2). Conclusions Based on the results, we observed stress and diet in pregnant mice affect the intestinal flora of maternal and neonatal. We were able to interpret the pathological mechanism of Taedok based on the principle of interaction between mother and newborn intestinal flora.

• Journal of Nutrition and Health
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• 제33권7호
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• pp.739-744
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• 2000

The purpose of this study was to elucidate protective effect of Fructus Schsandrae(FS) water extract against xanthine oxidase/hypoxanthine(XO/HX)-induced cardiotoxicity in myocardial cells this experiment was performed. Cardiotoxicity of XO/HX was examined by MTT(MTT [3-(4,5-dimethylthiazol-2-yl)-2.5,-diphenyl tetrazolium bromide) assay. XO/HX induced the decrease of cell viability. Also XO/HX induced the increase of LDH activity and the decrease of beating rate on cultured myocardial cells in a dose-dependent manner. To investigate cardioprotective effect of FS water extract cultures were preincubated with FS water extract for 3 hours. Cultures were then exposed to XO/HX for 72 hours. FS water extract have an efficacy in decreaasing LDH activity and increasing heart beating rate on cultured myocardial cells damaged by XO/HX. From the results it is suggested that XO/HX may show toxic effect in cultured myocardial cells derived from neonatal mouse and FS water extract is effective in the prevention of XO/HX-induced cardiotoxicity.