• Korean Journal of Ecology and Environment
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• v.55 no.2
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• pp.156-166
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• 2022

Understanding the characteristics of reservoir water quality is fundamental in reservoir ecosystem management. The water quality of reservoirs is affected by various factors including hydro-morphology of reservoirs, land use/cover, and human activities in their catchments. In this study, we classified 83 major reservoirs in South Korea based on nine physicochemical factors (pH, dissolved oxygen, chemical oxygen demand, total suspended solid, total nitrogen, total phosphorus, total organic carbon, electric conductivity, and chlorophyll-a) measured for five years (2015~2019). Study reservoirs were classified into five main clusters through hierarchical cluster analysis. Each cluster reflected differences in the water quality of reservoirs as well as hydromorphological variables such as elevation, catchment area, full water level, and full storage. In particular, water quality condition was low at a low elevation with large reservoirs representing cluster I. In the comparison of eutrophication status in major reservoirs in South Korea using the Korean trophic state index, in some reservoirs including cluster IV composed of lagoons, the eutrophication was improved compared to 2004~2008. However, eutrophication status has been more impaired in most agricultural reservoirs in clusters I, III, and V than past. Therefore, more attention is needed to improve the water quality of these reservoirs.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.4
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• pp.487-493
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• 2010

The purpose of this study was to evaluate antioxidant and antigenotoxic effects of Omija (Schizandra chinensis B.) extracted with various solvents (acetone, ethanol, and methanol). The total polyphenol content (TPC) of methanol extract (ME), ethanol extract (EE) and acetone extract (AE) from Omija were 1183.3, 1009.4, and 747.3 mg/100 g (garlic acid equivalents: GAE), respectively. Antioxidant effects of the Omija extracts was measured by DPPH radical-scavenging activity (RSA) and superoxide dismutase (SOD)-like activity. The $IC_{50}$ for DPPH RSA was in the order of EE $(1411.1\;{\mu}g/mL)$=AE $(1462.0\;{\mu}g/mL)$>ME $(1585.0\;{\mu}g/mL)$. The $IC_{50}$ for SOD-like activities was the highest in ME $(905.7\;{\mu}g/mL)$=EE $(970.3\;{\mu}g/mL)$>AE $(1579.4\;{\mu}g/mL)$. The antigenotoxic effect of Omija on DNA damage induced by $H_2O_2$ in human leukocytes was evaluated by comet assay. $H_2O_2$ induced DNA damage was effectively protected by all of the Omija extracts. Aectone extract of Omija showed the highest antigenotoxic effect ($IC_{50}$ value of AE is $14.6\;{\mu}g/mL$) followed by EE, and ME (21.4 and $34.4\;{\mu}g/mL$), respectively. As a result, we propose that Omija (Schizandra chinensis B.) can serve as a new natural source enriched with potent antioxidant and antigenotoxic agents.

• Journal of Microbiology and Biotechnology
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• v.26 no.4
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• pp.763-774
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• 2016

Equine gastric ulcer syndrome is one of the most frequently reported diseases in thoroughbred racehorses. Although several risk factors for the development of gastric ulcers have been widely studied, investigation of microbiological factors has been limited. In this study, the presence of Helicobacter spp. and the gastric microbial communities of thoroughbred racehorses having mild to severe gastric ulcers were investigated. Although Helicobacter spp. were not detected using culture and PCR techniques from 52 gastric biopsies and 52 fecal samples, the genomic sequences of H. pylori and H. ganmani were detected using nextgeneration sequencing techniques from 2 out of 10 representative gastric samples. The gastric microbiota of horses was mainly composed of Firmicutes (50.0%), Proteobacteria (18.7%), Bacteroidetes (14.4%), and Actinobacteria (9.7%), but the proportion of each phylum varied among samples. There was no major difference in microbial composition among samples having mild to severe gastric ulcers. Using phylogenetic analysis, three distinct clusters were observed, and one cluster differed from the other two clusters in the frequency of feeding, amount of water consumption, and type of bedding. To the best of our knowledge, this is the first study to investigate the gastric microbiota of thoroughbred racehorses having gastric ulcer and to evaluate the microbial diversity in relation to the severity of gastric ulcer and management factors. This study is important for further exploration of the gastric microbiota in racehorses and is ultimately applicable to improving animal and human health.

• ALGAE
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• v.34 no.3
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• pp.237-251
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• 2019

The dinoflagellate genus Alexandrium is known to often form harmful algal blooms causing human illness and large-scale mortality of marine organisms. Therefore, the population dynamics of Alexandrium species are of primary concern to scientists and aquaculture farmers. The growth rate of the Alexandrium species is the most important parameter in prediction models and nutrient conditions are critical parameters affecting the growth of phototrophic species. In Korean coastal waters, Alexandrium affine and Alexandrium fraterculus, of similar sizes, often form red-tide patches together. Thus, to understand bloom dynamics of A. affine and A. fraterculus, growth rates and nitrate uptake of each species as a function of nitrate ($NO_3$) concentration at $100{\mu}mol\;photons\;m^{-2}s^{-1}$ under 14-h light : 10-h dark and continuous light conditions were determined using a nutrient repletion method. With increasing $NO_3$ concentration, growth rates and $NO_3$ uptake of A. affine or A. fraterculus increased, but became saturated. Under light : dark conditions, the maximum growth rates of A. affine and A. fraterculus were 0.45 and $0.42d^{-1}$, respectively. However, under continuous light conditions, the maximum growth rate of A. affine slightly increased to $0.46d^{-1}$, but that of A. fraterculus largely decreased. Furthermore, the maximum nitrate uptake of A. affine and A. fraterculus under light : dark conditions were 12.9 and $30.1pM\;cell^{-1}d^{-1}$, respectively. The maximum nitrate uptake of A. affine under continuous light conditions was $16.4pM\;cell^{-1}d^{-1}$. Thus, A. affine and A. fraterculus have similar maximum growth rates at the given $NO_3$ concentration ranges, but they have different maximum nitrate uptake rates. A. affine may have a higher conversion rate of $NO_3$ to body nitrogen than A. fraterculus. Moreover, a longer exposure time to the light may confer an advantage to A. affine over A. fraterculus.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.8
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• pp.1359-1366
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• 2004

Ultra high temperature treated (UHT) skim milk and colloidal calcium phosphate-free skim milk were treated with microbial transglutaminase (TGase), ultracentrifuged at various rates, lyophilized, and observed for morphological properties with a scanning electron microscope (SEM). UHT skim milk showed small holes of associated micelles at lower centrifugal rates, and became thick and irregular, and fine particles were associated regularly at higher centrifugal rates. When UHT skim milk with TGase was incubated for 1 hour, casein micelles aggregated and broadened as centrifugation rate increased. When UHT skim milk with TGase was incubated for 8 hours, casein micelles were associated irregularly to large aggregates and widened. Colloidal calcium phosphate-free skim milk with TGase incubated for 1 hour and separated by two-step centrifugation showed aggregated lump, while the milk incubated for 8 hours with TGase was associated with broadened, compact, and regular layers as the centrifugation rate increased. Such phenomena were caused by heat treatment, protein crosslinking reaction catalyzed by TGase and conformational changes of casein molecules, and could be dependent on reaction time, temperature and ultracentrifugation rate.

• The Korea Journal of Herbology
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• v.24 no.3
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• pp.39-50
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• 2009

Objectives : Smilacis glabrae rhizoma (SG) has been traditionally used as a herbal medication of musculoskeletal disorders like arthritis, pain, convulsions, and syphilis in traditional Korean medicine. This study was investigated anti-oxidative and anti-inflammatory effect of fractionated extracts of Smilacis Glabrae Rhizoma in Human Umbilical Vein Endothelial Cell (HUVEC). Methods : SG extract prepared with methanol, and then fractionated with hexane, dichloromethane, ethylacetate, n-butanol and water. Inhibitory effect of SG onto free radical generation was determined by measuring DPPH, superoxide anions and nitric oxide scavenging activities in vitro. Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymethoxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. Intracelluar oxidation was analysed by DCF-DA assay. The nitric oxide (NO) production was measured by Griess reagent system. The levels of ICAM-1 and VCAM-1 expression were confirmed by western blot. And proinflammatory cytokines were measured by ELISA kit. Results : Our results indicated that fractionated extracts, especially ethyl acetate (EA) extract, significantly inhibited free radical generation, the TNF-$\alpha$-induced intracellular oxidation. Furthermore, the EA extract protected TNF-$\alpha$-induced adhesion to THP-1, expression of adhesion molecules accompanied by an attenuation of IL-6 and IL-8 formation in HUVEC. Conclusions : These results indicate that EA extract of SG have potential as an agent of atherosclerosis and other chronic inflammatory diseases including diabetes, hypertension, and arthritis.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.4
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• pp.339-344
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• 2000

Objective: To evaluate silane-coated silica particles (Sil-select) as an alternative to polyvinylpyrrolidone-coated particles (Percoll) for gradient separation of spermatozoa, for use in assisted reproduction. Methods: 20 normal semen based on WHO criteria were included in this study. Recovery of motile and morphologically normal spermatozoa after using two-layer Percoll and Sil-select gradient respectively was recorded. Motility, HOST (hypoosmotic swelling test) and the detection of malondialdehyde for LPO (lipid peroxidation) after 24 h of incubation at $37^{\circ}C$ in a 5% $CO_2$ incubator were compared. Results: Percoll (78.5%) and Sil-select (79.1%) showed a significant increase in the motility compared to ejaculate (60.9%) but no difference between Percoll and Sil-select. Normal sperm morphology significantly increased after Percoll (57.6%) and Sil-select (53.7%) compared to ejaculate (35.8%) but no difference between Percoll and Sil-select. No differences in the recovery of motile spermatozoa and motility, HOST and the production of malondialdehyde after 24 h incubation were found when comparing the use of Percoll and Sil-select. Conclusion: Sil-select seems to be an attractive alternative to Percoll for sperm separation in assisted reproduction.

• Macromolecular Research
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• v.9 no.4
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• pp.197-205
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• 2001

Platelet adhesion onto elastic polymeric biomaterials was tested in vitro by perfusing human whole blood at a shear rate of 100 sec$\^$-1/ for possible verification of mechanisms of initial platelet adhesion perfusion of blood on the polymeric substrates was performed after treatments either with or without pre-adsorption of 1% blood plasma, and either with or without residence of the protein-preadsorbed substrate in phosphate buffered solution. The surfaces employed were elastic polymers such as poly(ether urethane urea), poly(ether urethane), silicone urethane copolymer, silicone rubber and poly(ether urethane) with the anti-calcifying agent hydroxyethane bisphosphate. Each polymer surface treated was exposed in vitro to the dynamic, heparinized whole blood perfused for upto 6 min and the surface area of platelets initially adhered was measured by employing in situ epifluorescence video microscopy. The blood perfusion was performed on the surfaces treated at the following three different conditions: directly on the bare surfaces, after protein pre-adsorption and after residence in buffer for 3 days of the surfaces protein pre-adsorbed for 2 h. The effects of blood plasma pre-adsorption on the initial platelet adhesion was surface-dependent. The amount of the adsorbed fibrinogen and the surface coverage area of the adhered platelets were dependent on the surface conditions whether substrates were bare surfaces or protein pre-adsorbed ones. To test an effect of possible morphological (re)orientations of the adsorbed proteins on the initial platelet adhesion, the polymeric substrate pre-adsorbed with 1% blood plasma was immersed in phosphate buffered solution for 3 days and then exposed to physiological blood perfusion. The surface area of the platelets adhered on these surfaces was significantly different from that of the surfaces treated with protein pre-adsorption only. These results indicated that platelet adhesion was dependent on the surface property itself and pre-treatment conditions such as blood perfusion without any pre-adsorption of proteins, and blood perfusion either after protein pre-adsorption or after subsequent substrate residence in buffer of the substrate pre-adsorbed with proteins. Understanding of these results may guide for better designs of blood-contacting materials based on protein behaviors.

• Asian Pacific Journal of Cancer Prevention
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• v.16 no.16
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• pp.7161-7165
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• 2015

Background: Esophageal squamous cell carcinoma (ESCC) is a common cancer in the north east of India. The present study concerned the prevalence of human papilloma virus (HPV) in the ESCC in north eastern India and its impact on response to chemotherapy. Materials and Methods: p16 expression, a surrogate marker for HPV infection was assessed in 101 pre-treatment biopsies of locally advanced ESCC, reported from a comprehensive cancer centre in north east India, using immunohistochemistry. All patients received neo-adjuvant chemotherapy. Response was assessed clinically and histopathologically with attention to p16 expression. Results: p16 was expressed in 22% of ESCC (22 out of 101) and was more prevalent in patients who were more than 45 years of age (P=0.048). p16 positive tumors appeared more commonly in the upper 2/3 of the thoracic esophagus (18 in 22). Nine of the 22 (41%) p16 positive tumors achieved pathologic complete response following neo-adjuvant chemotherapy (P=0.008). There was a trend towards reduced mortality in this group (P=0.048). Some 9 of the 20 (45%) patients who achieved pathologic complete response were p16 positive. Conclusions: Expression of p16 in ESCC correlates with higher rate of pathologic complete remission in patients undergoing neo adjuvant chemotherapy and could be a predictive marker for response assessment.

• Korean Journal of Food Science and Technology
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• v.30 no.2
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• pp.450-455
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• 1998

Pine has been known as a traditional medicinal plant and as showing a physically beneficial function to a human being. Therefore, this study was performed to investigate the physiological activities of main pine neddles. Ethanol extracts from pinus needles did net exhibit any mutagenicity. On the contrary, inhibitory effects of ethanol extract were observed on mutagenicity induced by N-methyl-N'-nitro-N-nitrosoguanidine(MNNG), 4-nitroquinoline-1-oxide (4NQO), 3-amino-1,4-dimethyl-5H-pyrido-(4,3-b)indol (Trp-P-1) and benzo(a)pyrene $(B({\alpha})P)$ using Salmonella typhimurium reversion assay. On direct-acting mutagen (MNNG, 4NQO) and indirect-acting mutagen (Trp-P-1, $(B({\alpha})P)$, we observed higher inhibitory effect. Stepwise fractionation of the ethanol extract was done by using ether, chloroform, ethyl acetate, butanol and water to obtain effective fraction. Among them, water fractions $(100\;{\mu}g/plate)$ of Pinus thunbergii, Pinus rigida, Pinus densiflora and Pinus koraiensis showed high inhibition of 91.65%, 94.7%, 84.22% and 79.02%, respectively, on the mutagenicity of MNNG in Salmonella typhimurium TA100.