Na Mi Lee
Chung-Ang University
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Featured researches published by Na Mi Lee.
American Journal of Perinatology Reports | 2012
Ki Yeong Chung; Na Mi Lee; Eung Sang Choi; Byoung Hoon Yoo; Gwang Jun Kim; Seong Jae Cha; Gi Hyeon Kim; Mi Kyung Kim
Tailgut cysts are congenital lesions found in the presacral space. These have been mainly identified in adults and are rare in children, especially neonates. Here, we present the case of a neonate with a presacral cystic mass detected by prenatal ultrasonography that was diagnosed as a tailgut cyst after postnatal surgical removal. When a presacral cyst is encountered, tailgut cyst should be considered in the differential diagnosis.
Korean Journal of Pediatrics | 2013
Kyung Ah Seo; Sehhyun Kim; Na Mi Lee; Soo Ahn Chae
Purpose This study evaluated the extent of damage due to hypothermia in the mature and immature brain. Methods Hippocampal tissue cultures at 7 and 14 days in vitro (DIV) were used to represent the immature and mature brain, respectively. The cultures were exposed at 25℃ for 0, 10, 30, and 60 minutes (n=30 in each subgroup). Propidium iodide fluorescent images were captured 24 and 48 hours after hypothermic injury. Damaged areas of the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis. Results At 7 DIV, the tissues exposed to cold injury for 60 minutes showed increased damage in CA1 (P<0.001) and CA3 (P=0.005) compared to the control group at 48 hours. Increased damage to DG was observed at 24 (P=0.008) and 48 hours (P=0.011). The 14 DIV tissues did not demonstrate any significant differences compared with the control group, except for the tissues exposed for 30 minutes in which DG showed less damage at 48 hours than the control group (P=0.048). In tissues at 7 DIV, CA1 (P=0.040) and DG (P=0.013) showed differences in the duration of cold exposure. Conclusion The immature brain is more vulnerable to hypothermic injury than the mature brain.
Pediatric Neurology | 2012
In Ae Yoon; Na Mi Lee; Byoung Hoon Yoo; Byong Sop Lee; Han-Wook Yoo
Nonketotic hyperglycinemia, also known as glycine encephalopathy, is an autosomal recessive disorder of an inborn error of the glycine metabolism, caused by deficiency in the mitochondrial glycine cleavage enzyme. The majority of cases are caused by mutations in P-protein, one of the four components of the glycine cleavage enzyme, glycine decarboxylase. We describe a male neonate with hypotonia, hiccups, and persistent apnea, but without seizures. The patients glycine level in cerebrospinal fluid and plasma was 328.3 nmol/mL (reference value, 2.2-14.2 nmol/mL) and 1439 nmol/mL (reference value, 232-740 nmol/mL), respectively. The cerebrospinal fluid/plasma ratio of 0.228 represented an increase (normal range, <0.04). Two novel heterozygous missense mutations (c.1130C>T (p.A377V) and c.2081_2088del (p.A694DfsX11) in exons 8 and 18) in the glycine decarboxylase gene confirmed the diagnosis of nonketotic hyperglycinemia.
Brain Research | 2017
Na Mi Lee; Soo Ahn Chae; Hong Jun Lee
Neonatal hypoxic-ischemic brain injuries cause serious neurological sequelae, yet there is currently no effective treatment for them. We hypothesized that neurotrophic factors released into the medium by stem cells could supply hypoxia-damaged organotypic hippocampal slice cultures with regenerative abilities. We prepared organotypic slice cultures of the hippocampus of 7-day-old Sprague-Dawley rats based on the modified Stoppini method; slices were cultured for 14days in vitro using either Gahwilers medium (G-medium) or stem cell-conditioned medium (S-medium) as culture medium. At day 14 in vitro, hippocampal slice cultures were exposed to 95% N2 and 5% CO2 for 3h to induce hypoxic damage, the extent of which was then measured using propidium iodide fluorescence and immunohistochemistry images. We performed dot blotting to estimate neurotrophic/growth factor levels in the G- and S-media. Organotypic hippocampal slices cultured using S-medium after hypoxic injury were significantly less damaged than those cultured using G-medium. GLUT1, NGF, GDNF, VEGF, GCSF, and IGF2 levels were higher in S-medium than in G-medium, whereas FGF1, HIF, and MCP3 levels were not significantly different between media. In conclusion, we found that stem cell-conditioned medium had a neuroprotective effect against hypoxic injury, and that, of the various neurotrophic factors in S-medium, NGF, GDNF, and VEGF can contribute to neuroprotection.
Pediatric Gastroenterology, Hepatology & Nutrition | 2013
Kyung Ah Seo; Na Mi Lee; Gwang Jun Kim; Sin Weon Yun; Soo Ahn Chae; In Seok Lim; Eung Sang Choi; Byoung Hoon Yoo
Congenital chloride diarrhea (CLD) is a rare inherited autosomal recessive disorder. Mutations of the solute carrier family 26 member 3 gene cause profuse, chloride ion rich diarrhea, which results in hypochloremia, hyponatremia and metabolic alkalosis with dehydration. If a fetal ultrasound shows bowel dilatation suggestive of bowel obstruction, or if a neonate shows persistent diarrhea and metabolic alkalosis, CLD should be considered in the differential diagnosis. The severity of CLD varies, but early detection and early therapy can prevent complications including growth failure. We report a case of dizygotic twins affected by CLD who had been born to non-consanguineous parents. Both of them showed growth failure, but one of the twins experienced worse clinical course. He showed developmental delay, along with dehydration and severe electrolyte imbalance. He was diagnosed with CLD first at 6-month age, and then the other one was also diagnosed with CLD.
Korean Journal of Pediatrics | 2015
Seh Hyun Kim; Woo Soon Lee; Na Mi Lee; Soo Ahn Chae; Sin Weon Yun
Purpose The aim of this study was to investigate the potential effects of mild hypoxia in the mature and immature brain. Methods We prepared organotypic slice cultures of the hippocampus and used hippocampal tissue cultures at 7 and 14 days in vitro (DIV) to represent the immature and mature brain, respectively. Tissue cultures were exposed to 10% oxygen for 60 minutes. Twenty-four hours after this hypoxic insult, propidium iodide fluorescence images were obtained, and the damaged areas in the cornu ammonis 1 (CA1), CA3, and dentate gyrus (DG) were measured using image analysis. Results In the 7-DIV group compared to control tissue, hypoxia-exposed tissue showed decreased damage in two regions (CA1: 5.59%±2.99% vs. 4.80%±1.37%, P=0.900; DG: 33.88%±12.53% vs. 15.98%±2.37%, P=0.166), but this decrease was not statistically significant. In the 14-DIV group, hypoxia-exposed tissue showed decreased damage compared to control tissues; this decrease was not significant in the CA3 (24.51%±6.05% vs. 18.31%±3.28%, P=0.373) or DG (15.72%±3.47% vs. 9.91%±2.11%, P=0.134), but was significant in the CA1 (50.91%±5.90% vs. 32.30%±3.34%, P=0.004). Conclusion Although only CA1 tissues cultured for 14 DIV showed significantly less damage after exposure to hypoxia, the other tissues examined in this study showed a tendency towards less damage after hypoxic exposure. Therefore, mild hypoxia might play a protective role in the brain.
World Journal of Gastroenterology | 2009
Na Mi Lee; Sin Weon Yun; Soo Ahn Chae; Byoung Hoon Yoo; Seong Jae Cha; Byung Kook Kwak
Neonatal medicine | 2013
Ki Yeong Chung; Na Mi Lee; Sin Weon Yun; Soo Ahn Chae; In Seok Lim; Eung Sang Choi; Byoung Hoon Yoo
Perinatology | 2018
Jeong Min Lee; Hoon Bum Shin; Young Bae Choi; Na Mi Lee; Dae Yong Yi; Sin Weon Yun; Soo Ahn Chae; In Seok Lim
Neonatal medicine | 2018
Hoon Bum Shin; Na Li Yu; Na Mi Lee; Dae Yong Yi; Sin Weon Yun; Soo Ahn Chae; In Seok Lim