• Journal of Microbiology
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• v.34 no.2
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• pp.131-136
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• 1996

In order to known the extend of contribution to the degradation of organic materials and nutrient recycling by sulfate-reducing bacteria (SRB) and methane-producing bacteria (MPB) in sediment, the distribution and activity of these two groups of microorganisms were studied montly in 1994 at two sites, one littoral (Sanggulri) and the other profunndal (DAM), in Lake Soyang. In the seasonal distribution of two microorganisms, SRB were 1.07 $\times$ 10$^{3}$-2.42 $\times$ 10$^{5}$ cells/g-dry weight at Sanggulri, 2.40 $\times$ 10$^{5}$ -1.29 $\times$ 10$^{6}$ at Dam and MPB were 0.52 $\times$ 10$^{3}$ cells/g-dry weight at Sangguri and 1.44 $\times$ 10$^{3}$-6.89 $\times$ 10$^{3}$ at Dam. In these results, the density of SRB in Lake Soyang is much higher than other lakes. These high values might be due to higher sulfate concentration, 0.69-4.05 mM, than normal freshwater, 0.01-1.2 mM. And a good correlation of SRB and chlorophyll a concentration implied that the important environmental factor on distribution of SRB might be the concentration of available organic matter. In a comparison of sulfate-reducing rate and methane producing rate in 1995, the activity of SRB for the degradation of organic matter was higher than MPB by factor of 359. Conclusively SRB superior to MPB in the distribution and activity are more important annearobic bacteria in Lake Soyang sediments.

• Journal of Environmental Health Sciences
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• v.45 no.6
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• pp.613-621
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• 2019

Objectives: This study was performed to examine the relationship between health behaviors, living environment, and asthma in adolescents in Korea. Methods: Information on adolescents' characteristics, including demographic factors, health behaviors, and doctor's diagnosis of asthma was obtained from the Korean Youth Risk Behavior Web-based Survey (2015). In total, 68,043 middle and high school students participated. Environmental characteristics, including city park area and outdoor PM₁₀ concentrations in 2015 were obtained from the Korean Statistical Information Service. The adolescents' and environmental characteristics were merged by local information. Multiple logistic regression models were used to investigate the risk factors affecting asthma in adolescents. Results: The prevalence of asthma in adolescents in 2015 was 8.8%. In the multiple logistic regression analysis, adolescents who were male, attended middle school, suffered obesity, experienced tobacco smoking, had physical activity levels of 2 to 4 days, had higher stress levels, and lived in areas with outdoor PM₁₀ concentrations more than 47 ㎍/㎥ were more likely to have asthma, while adolescents who had middle levels of family economic status were less likely to do so. Conclusions: The fact that PM₁₀ concentration can affect asthma is an important point in this study. Risk factors identified in this study could be used as basic data for the prevention and management of asthma in Korea.

• Journal of Preventive Medicine and Public Health
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• v.49 no.6
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• pp.349-366
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• 2016

Objectives: We conducted a systematic review and meta-analysis to summarize current evidence regarding the association of parity and duration of breastfeeding with the risk of epithelial ovarian cancer (EOC). Methods: A systematic search of relevant studies published by December 31, 2015 was performed in PubMed and EMBASE. A random-effect model was used to obtain the summary relative risks (RRs) and 95% confidence intervals (CIs). Results: Thirty-two studies had parity categories of 1, 2, and ${\geq}3$. The summary RRs for EOC were 0.72 (95% CI, 0.65 to 0.79), 0.57 (95% CI, 0.49 to 0.65), and 0.46 (95% CI, 0.41 to 0.52), respectively. Small to moderate heterogeneity was observed for one birth (p<0.01; Q = 59.46; $I^2=47.9%$). Fifteen studies had breastfeeding categories of <6 months, 6-12 months, and >13 months. The summary RRs were 0.79 (95% CI, 0.72 to 0.87), 0.72 (95% CI, 0.64 to 0.81), and 0.67 (95% CI, 0.56 to 0.79), respectively. Only small heterogeneity was observed for <6 months of breastfeeding (p = 0.17; Q = 18.79, $I^2=25.5%$). Compared to nulliparous women with no history of breastfeeding, the joint effects of two births and <6 months of breastfeeding resulted in a 0.5-fold reduced risk for EOC. Conclusions: The first birth and breastfeeding for <6 months were associated with significant reductions in EOC risk.

• Journal of Preventive Medicine and Public Health
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• v.47 no.1
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• pp.36-46
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• 2014

Objectives: To evaluate the association between fracture risk and levothyroxine use in elderly women with hypothyroidism, according to previous osteoporosis history. Methods: We conducted a cohort study from the Korean Health Insurance Review and Assessment Service claims database from January 2005 to June 2006. The study population comprised women aged ${\geq}65$ years who had been diagnosed with hypothyroidism and prescribed levothyroxine monotherapy. We excluded patients who met any of the following criteria: previous fracture history, hyperthyroidism, thyroid cancer, or pituitary disorder; low levothyroxine adherence; or a follow-up period <90 days. We categorized the daily levothyroxine doses into 4 groups: ${\leq}50{\mu}g/d$, 51 to $100{\mu}g/d$, 101 to $150{\mu}g/d$, and > $150{\mu}g/d$. The hazard ratios (HRs) and 95% confidence intervals (CIs) were estimated with the Cox proportional hazard model, and subgroup analyses were performed according to the osteoporosis history and osteoporosis-specific drug prescription status. Results: Among 11 155 cohort participants, 35.6% had previous histories of osteoporosis. The adjusted HR of fracture for the > $150{\mu}g/d$ group, compared with the 51 to $100{\mu}g/d$ group, was 1.56 (95% CI, 1.03 to 2.37) in osteoporosis subgroup. In the highly probable osteoporosis subgroup, restricted to patients who were concurrently prescribed osteoporosis-specific drugs, the adjusted HR of fracture for the > $150{\mu}g/d$ group, compared with the 51 to 100 ${\mu}g/d$ group, was 1.93 (95% CI, 1.14 to 3.26). Conclusions: While further studies are needed, physicians should be concerned about potential levothyroxine overtreatment in elderly osteoporosis patients.

• Parasites, Hosts and Diseases
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• v.41 no.1
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• pp.69-73
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• 2003

Lymphatic filariasis due to Brugia malayi infection was endemic in several areas of South Korea. The infection was controlled, or disappeared, in most areas, with the exception of the remote southwestern islands of Jeonranam-do, including the Heugsan Islands. To discover its current situation, a small-scale survey was performed on the Heugsan islands in September 2000. A total of 378 people, 151 male and 227 female, living in 8 villages (6 on Daeheugsan-do, 1 on Daejang-do, and 1 on Yeongsan-do) were subjected to a night blood survey for microfilaremia, and physical examination for elephantiasis on the extremities. There were 6 (1.6%) microfilaria positive cases, all in females aged 57-72 years, and from only two villages of the Daeheugsan-do area. There were 4 patients with lower leg elephantiasis, but they showed no microfilaremia. The results show that a low-grade endemicity of filariasis remains on the Daeheugsan-do.

• BMB Reports
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• v.56 no.9
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• pp.482-487
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• 2023

Hematopoiesis is regulated by crosstalk between long-term repopulating hematopoietic stem cells (LT-HSCs) and supporting niche cells in the bone marrow (BM). Here, we describe the role of KAI1, which is mainly expressed on LT-HSCs and rarely on other hematopoietic stem-progenitor cells (HSPCs), in niche-mediated LT-HSC maintenance. KAI1 activates TGF-β1/Smad3 signal in LT-HSCs, leading to the induction of CDK inhibitors and inhibition of the cell cycle. The KAI1-binding partner DARC is expressed on macrophages and stabilizes KAI1 on LT-HSCs, promoting their quiescence. Conversely, when DARC+ BM macrophages were absent, the level of surface KAI1 on LT-HSCs decreases, leading to cell-cycle entry, proliferation, and differentiation. Thus, KAI1 acts as a functional surface marker of LT-HSCs that regulates dormancy through interaction with DARC-expressing macrophages in the BM stem cell niche. Recently, we showed very special and rare macrophages expressing α-SMA+ COX2+ & DARC+ induce not only dormancy of LT-HSC through interaction of KAI1-DARC but also protect HSCs by down-regulating ROS through COX2 signaling. In the near future, the strategy to combine KAI1-positive LT-HSCs and α-SMA/Cox2/DARC triple-positive macrophages will improve the efficacy of stem cell transplantation after the ablative chemo-therapy for hematological disorders including leukemia.

• Journal of Urban Science
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• v.9 no.1
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• pp.17-31
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• 2020

This study aims to analyze the relations among greenbelt, urban land surface temperature empirically in order to assess the environmental effects of the greenbelt in the Seoul metropolitan area, objectively. For this purpose, this study conducts an empirical analysis of impacts of greenbelt on urban land surface temperature using a multiple-regression model. The main data employed in the analysis include real-time air pollution data, Landsat 8-OLI Landsat imagery data, KLIS data and Jip-gye-gu data. The major findings are summarized as follows. NDVI has a negative (-) correlation with the land surface temperature, and the urban temperature is high in areas with poor vegetation. The land surface temperature is low in residential or commercial areas, while the temperature is high in industrial areas. The temperature is low in green fields, open spaces, and river areas. it is found that the urban land surface temperature is low in the greenbelt zone. In the greenbelt zone, there is an effect that reduces the land surface temperature by 1% on average, as compared to that at the center of the Seoul metropolitan area. Especially, the center of the Seoul metropolitan area, in a range from 0.6% to 1.9% of the average temperature, the temperature gets lower up to approximately 3km from the greenbelt boundary.

• The Plant Pathology Journal
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• v.26 no.1
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• pp.8-16
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• 2010

The phytopathogenic fungus Magnaporthe oryzae is a major limiting factor in rice production. To understand the genetic basis of M. oryzae pathogenic development, we previously analyzed a library of T-DNA insertional mutants of M. oryzae, and identified ATMT0879A1 as one of the pathogenicity-defective mutants. Molecular analyses and database searches revealed that a single TDNA insertion in ATMT0879A1 resulted in functional interference with an annotated gene, MGG00056, which encodes a short-chain dehydrogenase/reductase (SDR). The mutant and annotated gene were designated as $MoSDR1^{T-DNA}$ and MoSDR1, respectively. Like other SDR family members, MoSDR1 possesses both a cofactor-binding motif and a catalytic site. The expression pattern of MoSDR1 suggests that the gene is associated with pathogenicity and plays an important role in M. oryzae development. To understand the roles of MoSDR1, the deletion mutant ${\Delta}Mosdr1$ for the gene was obtained via homology-dependent gene replacement. As expected, ${\Delta}Mosdr1$ was nonpathogenic; moreover, the mutant displayed pleiotropic defects in conidiation, conidial germination, appressorium formation, penetration, and growth inside host tissues. These results suggest that MoSDR1 functions as a key metabolic enzyme in the regulation of development and pathogenicity in M. oryzae.

• Journal of Korean Neurosurgical Society
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• v.53 no.2
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• pp.112-114
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• 2013

Bilateral abducens nerve palsy related to ruptured aneurysm of the anterior communicating artery (ACoA) has only been reported in four patients. Three cases were treated by surgical clipping. No report has described the clinical course of the isolated bilateral abducens nerve palsy following ruptured ACoA aneurysm obliterated with coil. A 32-year-old man was transferred to our institution after three days of diplopia, dizziness and headache after the onset of a 5-minute generalized tonic-clonic seizure. Computed tomographic angiography revealed an aneurysm of the ACoA. Magnetic resonance imaging showed focal intraventricular hemorrhage without brain stem abnormalities including infarction or space-occupying lesion. Endovascular coil embolization was conducted to obliterate an aneurysmal sac followed by lumbar cerebrospinal fluid (CSF) drainage. Bilateral paresis of abducens nerve completely recovered 9 weeks after ictus. In conclusion, isolated bilateral abducens nerve palsy associated with ruptured ACoA aneurysm may be resolved successfully by coil embolization and lumbar CSF drainage without directly relieving cerebrospinal fluid pressure by opening Lillequist's membrane and prepontine cistern.

• Archives of Pharmacal Research
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• v.21 no.3
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• pp.266-272
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• 1998

The present study investigated the antitumor activity of the aqueous-alcoholic extracts from unripe cotton balls of Gossypium indicum. An Exposure of murine B16 melanoma and L1210 lymphoma cells to the extracts resulted in their severe deaths in time- and concentration-dependent manners. Of the extracts, hydrophilic fractions were most efficacious for the antitumor activity and found to contain certain amounts of catechin and its derivatives. The hydrophilic extract fraction C36B2-8 had approximately 10 times more cytotoxic effects on B12 and L1210 cells than on isolated murine thymocytes. High concentrations (>150 $\mu$g/ml) of C 36B3-8 mainly induced necrotic cell death. At low concentrations (<100 $\mu$g/ml), however, C 36B3-8 induced not only necrosis but also apoptosis of the two tumor cell lines, which was proved by the TUNEL staining and DNA fragmentation techniques. The data indicate that certain ingredients of the cotton ball extract of G. indicum have an antitumor activity.