• Clinical and Experimental Pediatrics
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• v.46 no.11
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• pp.1112-1117
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• 2003

Purpose : Recent advances in the methods of treating cancer in young patients have led to both an increased frequency of CNS complications as well as prolonged life expectancy. We intend to analyze the clinical aspects and laboratory findings of patients with CNS complications during and after treatment. Methods : We reviewed the medical records of 174 childhood cancer patients treated with chemotherapy admitted to the Dept. of Pediatrics, Keimyung University Dongsan Hospital, from January 1995 to November 2002. Among them, 15 cases with CNS complications were investigated in this study. Results : CNS abnormalities were found in 13 patients by CT or MRI during treatment such as leukoencephalopathy(n=7), mineralizing microangiopathy(n=4), brain infarction(n=3), intracranial hemorrhage(n=1), and hypoxic ischemic encephalopathy(n=1). It was found that two patients had two or more CNS abnormalities. Two patients who had no imaging abnormalities had convulsions, possibly after the addition of intrathecal methotrexate. The patients with intracranial hemorrhage and brain infarction had rapid and fatal clinical courses. The hypoxic ischemic encephalopathy following electrolyte imbalance completely recovered after correction of electrolyte. Conclusion : The CNS complications that occur during and after chemotherapy influence prognoses significantly, and remain neurologic sequelae. Therefore early diagnosis and prophylaxis for CNS complications and regular physical examination of patients who have recieved cancer therapy are strongly recommended.

• Clinical and Experimental Pediatrics
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• v.62 no.12
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• pp.444-449
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• 2019

Background: Sixty percent of infants with severe neonatal hypoxic-ischemic encephalopathy die, while most survivors have permanent disabilities. Treatment for neonatal hypoxic-ischemic encephalopathy is limited to therapeutic hypothermia, but it does not offer complete protection. Here, we investigated whether hypoxia-inducible factor (HIF) promotes cell survival and suggested neuroprotective strategies. Purpose: HIF-1α deficient mice have increased brain injury after neonatal hypoxia-ischemia (HI), and the role of HIF-2α in HI is not well characterized. Copper-zinc superoxide dismutase (SOD)1 overexpression is not beneficial in neonatal HI. The expression of HIF-1α and HIF-2α was measured in SOD1 overexpressing mice and compared to wild-type littermates to see if alteration in expression explains this lack of benefit. Methods: On postnatal day 9, C57Bl/6 mice were subjected to HI, and protein expression was measured by western blotting in the ipsilateral cortex of wild-type and SOD1 overexpressing mice to quantify HIF-1α and HIF-2α. Spectrin expression was also measured to characterize the mechanism of cell death. Results: HIF-1α protein expression did not significantly change after HI injury in the SOD1 overexpressing or wild-type mouse cortex. However, HIF-2α protein expression increased 30 minutes after HI injury in the wild-type and SOD1 overexpressing mouse cortex and decreased to baseline value at 24 hours after HI injury. Spectrin 145/150 expression did not significantly change after HI injury in the SOD1 overexpressing or wild-type mouse cortex. However, spectrin 120 expression increased in both wild-type and SOD1 overexpressing mouse at 4 hours after HI, which decreased by 24 hours, indicating a greater role of apoptotic cell death. Conclusion: HIF-1α and HIF-2α may promote cell survival in neonatal HI in a cell-specific and regional fashion. Our findings suggest that early HIF-2α upregulation precedes apoptotic cell death and limits necrotic cell death. However, the influence of SOD was not clarified; it remains an intriguing factor in neonatal HI.

• Clinical and Experimental Pediatrics
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• v.51 no.2
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• pp.170-180
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• 2008

Purpose : Some antibiotics were known to exert neuroprotective effects in the animal model of hypoxic-ischemic (H-I) brain injury, but the mechanism is still unclear. A recent study reported that geneticin (G418), an aminoglycoside antibiotic, increased survival of human breast cancer cells by suppressing apoptosis. We investigated the neuroprotective effects of systemically administrated geneticin via anti-apoptosis following the H-I brain injury Methods : Seven-day-old Sprague-Dawley rat pups were subjected to unilateral (left) common carotid artery occlusion followed by 2.5 hours of hypoxic exposure and the cortical cell culture of rat brain was done under a hypoxic incubator. Apoptosis was measured in the injured hemispheres 7 days after H-I insult and in the injured cells from hypoxic chamber using morphologic analysis by Terminal dUTP Nick-end Labeling(TUNEL) assay and immunohistochemistry for caspase-3, and cytologic analysis by western blot and real time PCR for bax, bcl-2, and caspase-3. Results : The gross appearance and hematoxylin and eosin stain revealed increased brain volume in the geneticin-treated animal model of perinatal H-I brain injury. The TUNEL assay revealed decreased apoptotic cells after administration of geneticin in the cell culture model of anoxia. Immunohistochemistry showed decreased caspase-3 expression in geneticin-treated cortical cell culture. Western blot and real-time PCR showed decreased caspase-3 expression and decreased ratio of Bax/Bcl-2 expression in geneticin-treated animal model. Conclusion : Geneticin appears to exert a neuroprotective effect against perinatal H-I brain injury at least via anti-apoptosis. However, more experiments are needed in order to demonstrate the usefulness of geneticin as a preventive and rescue treatment for H-I brain injuries of neonatal brain.

• BMB Reports
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• v.53 no.11
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• pp.600-604
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• 2020

Macrophages are re-educated and polarized in response to myocardial infarction (MI). The M2 anti-inflammatory phenotype is a known dominator of late stage MI. Mesenchymal stem cells (MSCs) represent a promising tool for cell therapy, particularly heart related diseases. In general, MSCs induce alteration of the macrophage subtype from M1 to M2, both in vitro and in vivo. We conjectured that hypoxic conditions can promote secretome productivity of MSCs. Hypoxia induces TGF-β1 expression, and TGF-β1 mediates M2 macrophage polarization for anti-inflammation and angiogenesis in infarcted areas. We hypothesized that macrophages undergo advanced M2 polarization after exposure to MSCs in hypoxia. Treatment of MSCs derived hypoxic conditioned medium (hypo-CM) promoted M2 phenotype and neovascularization through the TGF-β1/Smad3 pathway. In addition, hypo-CM derived from MSCs improved restoration of ischemic heart, such as attenuating cell apoptosis and fibrosis, and ameliorating microvessel density. Based on our results, we propose a new therapeutic method for effective MI treatment using regulation of macrophage polarization.

• Clinical and Experimental Pediatrics
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• v.60 no.6
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• pp.181-188
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• 2017

Purpose: Hypoxic-ischemic encephalopathy is a significant cause of neonatal morbidity and mortality. Erythropoietin (EPO) is emerging as a therapeutic candidate for neuroprotection. Therefore, this study was designed to determine the neuroprotective role of recombinant human EPO (rHuEPO) and the possible mechanisms by which mitogen-activated protein kinase (MAPK) signaling pathway including extracellular signal-regulated kinase (ERK1/2), JNK, and p38 MAPK is modulated in cultured cortical neuronal cells and astrocytes. Methods: Primary neuronal cells and astrocytes were prepared from cortices of ICR mouse embryos and divided into the normoxic, hypoxia (H), and hypoxia-pretreated with EPO (H+EPO) groups. The phosphorylation of MAPK pathway was quantified using western blot, and the apoptosis was assessed by caspase-3 measurement and terminal deoxynucleotidyl transferase dUTP nick end labeling assay. Results: All MAPK pathway signals were activated by hypoxia in the neuronal cells and astrocytes (P<0.05). In the neuronal cells, phosphorylation of ERK-1/-2 and apoptosis were significantly decreased in the H+EPO group at 15 hours after hypoxia (P<0.05). In the astrocytes, phosphorylation of ERK-1/-2, p38 MAPK, and apoptosis was reduced in the H+EPO group at 15 hours after hypoxia (P<0.05). Conclusion: Pretreatment with rHuEPO exerts neuroprotective effects against hypoxic injury reducing apoptosis by caspase-dependent mechanisms. Pathologic, persistent ERK activation after hypoxic injury may be attenuateed by pretreatment with EPO supporting that EPO may regulate apoptosis by affecting ERK pathways.

• Korean Journal of Veterinary Research
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• v.64 no.1
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• pp.2.1-2.8
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• 2024

This study was performed to assess the antiapoptotic effect of canine platelet-rich plasma (PRP) treated on the canine adipose-derived mesenchymal stem cells (cMSCs) under cold ischemic conditions. The effect of preventing apoptosis of cMSCs was evaluated in the apoptotic condition induced by cold ischemic injury in vitro. To determine the progression of apoptosis, the changes in cell nucleus were observed using 4',6-diamidino-2-phenylindole (DAPI) fluorescence staining. In addition, we examined the mitochondrial membrane potential (MMP) and caspase-3 activity. When the cold hypoxic injury was applied to cMSCs, the apoptotic change was observed by DAPI staining, mitochondrial staining for MMP, and caspase-3 assay. PRP significantly decreased the number of apoptotic cells. Nuclear shrinkage and fragmentation of apoptotic cells in control groups were observed by DAPI staining. The MMP was recovered by the treatment of PRP. In addition, when the luminescence intensity was measured for caspase-3 activity, the value was significantly higher in the PRP treated groups than the control groups. The results of this study showed that the PRP may have a beneficial effect on apoptosis induced by cold ischemic injury.

• Molecules and Cells
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• v.37 no.10
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• pp.734-741
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• 2014

Histone modifications on major transcription factor target genes are one of the major regulatory mechanisms controlling adipogenesis. Plant homeodomain finger 2 (PHF2) is a Jumonji domain-containing protein and is known to demethylate the histone H3K9, a repressive gene marker. To better understand the function of PHF2 in adipocyte differentiation, we constructed stable PHF2 knock-down cells by using the mouse pre-adipocyte cell line 3T3-L1. When induced with adipogenic media, PHF2 knock-down cells showed reduced lipid accumulation compared to control cells. Differential expression using a cDNA microarray revealed significant reduction of metabolic pathway genes in the PHF2 knock-down cell line after differentiation. The reduced expression of major transcription factors and adipokines was confirmed with reverse transcription- quantitative polymerase chain reaction and Western blotting. We further performed co-immunoprecipitation analysis of PHF2 with four major adipogenic transcription factors, and we found that CCATT/enhancer binding protein (C/EBP)${\alpha}$ and C/EBP${\delta}$ physically interact with PHF2. In addition, PHF2 binding to target gene promoters was confirmed with a chromatin immunoprecipitation experiment. Finally, histone H3K9 methylation markers on the PHF2-binding sequences were increased in PHF2 knock-down cells after differentiation. Together, these results demonstrate that PHF2 histone demethylase controls adipogenic gene expression during differentiation.

• The Journal of Korea Assosiation for Disability and Oral Health
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• v.8 no.1
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• pp.22-25
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• 2012

Hypoxic ischemic encephalopathy(HIE) is a condition that occurs when the entire brain is deprived of an adequate oxygen supply and associated in most cases with oxygen deprivation in the neonate due to birth asphyxia. Children with HIE develop problems such as cerebral palsy, mental retardation, learning difficulties, and other disabilities. We hereby report the case of treating a child patient with HIE whose chief complaint of severe lingual ulceration. A 12-month-old boy referred to our hospital to treat ulcers of ventral surface of tongue. He has been suffering from lingual ulceration due to persistent tongue thrusting. He has bitten his own tongue involuntary. The ulceration was apparently seemed to be not healed because of the constant irritation by lower incisors. So we designed tongue protector to prevent lingual ulcers. The appliance was proved to be effective to reduce tongue trauma by lower incisors and periodic follow-up is needed.

• 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.

• Clinical and Experimental Pediatrics
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• v.56 no.3
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• pp.139-142
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• 2013

X-linked recessive myotubular myopathy (XLMTM) is a severe congenital muscle disorder caused by mutations in the MTM1 gene and characterized by severe hypotonia and generalized muscle weakness in affected males. It is generally a fatal disorder during the neonatal period and early infancy. The diagnosis is based on typical histopathological findings on muscle biopsy, combined with suggestive clinical features. We experienced a case of a newborn who required intubation and ventilator care because of profound hypotonia and respiratory difficulty. The preliminary diagnosis at the time of request for retrieval was hypoxic ischemic encephalopathy, but the infant was clinically reevaluated for generalized weakness and muscle atrophy. Muscle biopsies showed variability in fiber size and centrally located nuclei in nearly all the fibers. We detected an MTM1 gene mutation of c.1261-1C>A in the intron 10 region, and diagnosed the neonate with myotubular myopathy. The same mutation was detected in his mother.