• Nutrition Research and Practice
• /
• v.10 no.1
• /
• pp.11-18
• /
• 2016

BACKGROUND/OBJECTIVES: Type 2 diabetes (T2D) is more frequently diagnosed and is characterized by hyperglycemia and insulin resistance. $\small{D}$-xylose, a sucrase inhibitor, may be useful as a functional sugar complement to inhibit increases in blood glucose levels. The objective of this study was to investigate the anti-diabetic effects of $\small{D}$-xylose both in vitro and stretpozotocin (STZ)-nicotinamide (NA)-induced models in vivo. MATERIALS/METHODS: Wistar rats were divided into the following groups: (i) normal control; (ii) diabetic control; (iii) diabetic rats supplemented with a diet where 5% of the total sucrose content in the diet was replaced with $\small{D}$-xylose; and (iv) diabetic rats supplemented with a diet where 10% of the total sucrose content in the diet was replaced with $\small{D}$-xylose. These groups were maintained for two weeks. The effects of $\small{D}$-xylose on blood glucose levels were examined using oral glucose tolerance test, insulin secretion assays, histology of liver and pancreas tissues, and analysis of phosphoenolpyruvate carboxylase (PEPCK) expression in liver tissues of a STZ-NA-induced experimental rat model. Levels of glucose uptake and insulin secretion by differentiated C2C12 muscle cells and INS-1 pancreatic ${\beta}$-cells were analyzed. RESULTS: In vivo, $\small{D}$-xylose supplementation significantly reduced fasting serum glucose levels (P < 0.05), it slightly reduced the area under the glucose curve, and increased insulin levels compared to the diabetic controls. $\small{D}$-xylose supplementation enhanced the regeneration of pancreas tissue and improved the arrangement of hepatocytes compared to the diabetic controls. Lower levels of PEPCK were detected in the liver tissues of $\small{D}$-xylose-supplemented rats (P < 0.05). In vitro, both 2-NBDG uptake by C2C12 cells and insulin secretion by INS-1 cells were increased with $\small{D}$-xylose supplementation in a dose-dependent manner compared to treatment with glucose alone. CONCLUSIONS: In this study, $\small{D}$-xylose exerted anti-diabetic effects in vivo by regulating blood glucose levels via regeneration of damaged pancreas and liver tissues and regulation of PEPCK, a key rate-limiting enzyme in the process of gluconeogenesis. In vitro, $\small{D}$-xylose induced the uptake of glucose by muscle cells and the secretion of insulin cells by ${\beta}$-cells. These mechanistic insights will facilitate the development of highly effective strategy for T2D.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
• /
• v.14 no.1
• /
• pp.1-15
• /
• 2019

The purpose of this study is to analyze the relationship between entrepreneurship and entrepreneurial intention. This relationship has been conceptually addressed in many previous studies and has been empirically tested. However, this study is different from the previous studies in the following four points. First, we measured entrepreneurial intention by manipulating launching a start-up as a relative concept for employment, which is consistent with the conceptual definition of entrepreneurial intention (i.e. entrepreneurial decision making in the process of career choice). Second, it is distinguished from previous researches in that it uses the question of preference for "action" with regard to job choice. Third, we expanded the opportunity for discussion using the youth panel data of the Korea Employment Information Service. Fourth, the altruistic purpose is included in the category of entrepreneurship. Empirical results showed that intentions of entrepreneurship were stronger when the need for achievement was intense, internal control tendency was intended, risk-taking propensity was sturdy, and autonomous tendency was high. However, innovation and aggressiveness are not statistically related to entrepreneurial intention. On the other hand, the altruistic tendency was found to have a negative correlation with entrepreneurial intention. The results of this study can provide meaningful implications for both private sector investors and government policy makers.

• Laboraroty Animal Research
• /
• v.34 no.4
• /
• pp.176-184
• /
• 2018

In this study, we observed chronological changes in the immunoreactivity and expression level of myelin basic protein (MBP), one of the most abundant proteins in the central nervous system, in the hippocampus of Zucker diabetic fatty (ZDF) rats and their control littermates (Zucker lean control; ZLC). In the ZLC group, body weight steadily increased with age; the body weight of the ZDF group, however, peaked at 30 weeks of age, and subsequently decreased. Based on the changes of body weight, animals were divided into the following six groups: early (12-week), middle (30-week), and chronic (52-week) diabetic groups and their controls. MBP immunoreactivity was found in the alveus, strata pyramidale, and lacunosum-moleculare of the CA1 region, strata pyramidale and radiatum of the CA3 region, and subgranular zone, polymorphic layer, and molecular layer of the dentate gyrus. MBP immunoreactivity was lowest in the hippocampus of 12-week-old rats in the ZLC group, and highest in 12-week-old rats in the ZDF group. Diabetes increased MBP levels in the 12-week-old group, while MBP immunoreactivity decreased in the 30-week-old group. In the 52-week-old ZLC and ZDF groups, MBP immunoreactivity was detected in the hippocampus, similar to the 30-week-old ZDF group. Western blot results corroborated with immunohistochemical results. These results suggested that changes in the immunoreactivity and expression of MBP in the hippocampus might be a compensatory response to aging, while the sustained levels of MBP in diabetic animals could be attributed to a loss of compensatory responses in oligodendrocytes.

• Journal of The Korean Society of Integrative Medicine
• /
• v.9 no.3
• /
• pp.87-97
• /
• 2021

Purpose : The purpose of this meta-analysis was to evaluate the effects of transcranial direct current stimulation on the lower extremity function of stroke patients. Methods : Domestic data were gathered from studies that conducted clinical trials associated with transcranial direct current stimulation and its impact on lower extremity function of stroke patients. A total of 592 studies published between 2012 and 2020 were identified, with 7 studies satisfying the inclusion data. The studies consisted of patient, intervention, comparison, and outcome (PICO) data. The search outcomes were items associated with muscle activity, balance, muscle strength and walking ability. Cochrane risk of bias (ROB) was used to evaluate the quality of 3 randomized control trials. The quality of 4 non-randomized control trials was evaluated using risk of bias assessment tool for non-randomized studies (RoBANS). Effect sizes in this study were computed as the corrected standard mean difference (SMD). A random-effect model was used to analyze the effect size because of the high heterogeneity among the studies. Egger's regression and 'trim-and-fill' tests were carried out to analyze the publishing bias. Results : The following factors had a large total effect size (Hedges's g=2.10, 95 %CI=1.54~2.66) involving transcranial direct current stimulation on stroke patients: muscle activity (Hedges's g=2.38, 95 %CI=1.08~3.68), balance (Hedges's g4=2.41, 95 %CI=1.33~3.60), walking ability (Hedges's g=1.54, 95 %CI=0.49~2.59), and muscle strength (Hedges's g=2.45, 95 % CI: 0.85~4.05). Egger's regression test showed that the publishing bias had statistically significant differences but 'trim-and-fill' test showed that there was still statistical difference. Conclusion : This study provides evidence for the effectiveness of transcranial direct current stimulation on the lower extremity in terms of muscle activity, balance, walking ability, and muscle strength in stroke patients. However, due to the low quality of studies and high heterogeneity factors, the results of our study should be interpreted cautiously.

• Korean Journal of Microbiology
• /
• v.49 no.4
• /
• pp.360-368
• /
• 2013

Recently interactive water fountains are gaining popularity in making public facilities in South Korea. The total number of interactive fountains is rapidly growing at the rate of >50% annually. In this study, we performed quantitative microbial risk assessment to estimate infection risks in children by Legionella spp. while playing in interactive fountains. The exposure dose for a given concentration of Legionella in water was calculated using water-aerosol partition rate of Legionella, exposure duration, inhalation rate, and deposit rate of aerosols in the lungs following inhalation. The dose was converted to infection risk by using the dose-response function developed for L. pneumophila. High weight and/or old children, i.e., 12-year children, running around in fountains were the highest risk group by showing >0.05 infection probability for fountain waters containing ${\geq}10^4$ CFU/L Legionella. The result supported the current guideline by Korea Centers for Disease Control and Prevention, which permits use of water with < $10^3$ CFU/L Legionella cells for all purposes. However, the results still warrant further evaluation of the guideline to accommodate risks for children because the dose-response relationship in the model was developed for healthy adults. Further risk assessment studies need to be conducted by employing dose-response model for children who generally carries weaker immune system than adults.

• Journal of The Korean Dental Society of Anesthesiology
• /
• v.14 no.1
• /
• pp.49-56
• /
• 2014

Background: Propofol (2.6-diisopropylphenol) is a widely used intravenous anesthetic agent for the induction and maintenance of anesthesia during surgeries and sedation for ICU patients. Propofol has a structural similarity to the endogenous antioxidant vitamin E and exhibits antioxidant activities.13) However, the mechanism of propofol on hypoxia/reoxygenation (H/R) injury has yet to be fully elucidated. We investigated how P-PostC influences the autophagy and cell death, a cellular damage occurring during the H/R injury. Methods: The groups were randomly divided into the following groups: Control: cells were incubated in normoxia (5% CO2, 21% O2, and 74% N2) without propofol treatment. H/R: cells were exposed to 24 h of hypoxia (5% CO2, 1% O2, and 94% N2) followed by 12 h of reoxygenation (5% CO2, 21% O2, and 74% N2). H/R + P-PostC: cells post-treated with propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation. 3-MA + P-PostC: cells pretreated with 3-MA and post-treated propofol were exposed to 24 h of hypoxia followed by 12 h of reoxygenation Results: The results of our present study provides a new direction of research on mechanisms of propofol-mediated cytoprotection. There are three principal findings of these studies. First, the application of P-PostC at the onset of reoxygenation after hypoxia significantly increased COS-7 cell viability. Second, the cellular protective effect of P-PostC in H/R induced COS-7 cells was probably related to activation of intra-cellular autophagy. And third, the autophagy pathway inhibitor 3-MA blocked the protective effect of P-PostC on cell viability, suggesting a key role of autophagy in cellular protective effect of P-PostC. Conclusions: These data provided evidence that P-PostC reduced cell death in H/R model of COS-7 cells, which was in agreement with the protection by P-PostC demonstrated in isolated COS-7 cells exposed to H/R injury. Although the this study could not represent the protection by P-PostC in vivo, the data demonstrate another model in which endogenous mechanisms evoked by P-PostC protected the COS-7 cells exposed to H/R injury from cell death.

• The Journal of Korean Physical Therapy
• /
• v.22 no.3
• /
• pp.79-85
• /
• 2010

Purpose: Many trials for new therapeutic approaches such as stem cell-based transplantation have been conducted to improve the repair and regeneration of injured cord tissue and to restore functions following spinal cord injury (SCI) in animals and humans. Adipose tissue-derived stromal cells (ATSCs) have multi-lineage potential to differentiate into cells with neuron-like morphology. Most studies of stem cell transplantation therapy after SCI are focused on cellular regeneration and restoration of motor function, but not on unwanted effects after transplantation such as neuropathic pain. This study was focused on whether transplantation of ATSCs could facilitate or attenuate hindpaw pain responses to heat, cold and mechanical stimulation, as well as on improvement of locomotor function in a rat with SCI. Methods: A spinal cord injury rat model was produced using an NYU impactor by dropping a 10 g rod from a height of 25 mm on to the T9 segment. Human ATSCs (hATSCs; approximately $5{\times}10^5$ cells) or DMEM were injected into the perilesional area 9 days after the SCI. After transplantation, hindpaw withdrawal responses to heat, cold and mechanical allodynia were measured over 7 weeks. Motor recovery on the Basso, Beattie, and Bresnahan (BBB) locomotor rating scale and on the inclined plane test were also evaluated. Results: The present study demonstrated that increased hindpaw withdrawal responses to cold allodynia was observed in both groups after transplantation, but the development of cold-induced allodynia in the hATSC transplantation group was significantly larger than in the control group. The difference between the two groups in locomotor functional improvement after SCI was also significant. Conclusion: Careful consideration not only of optimal functional benefits but also of unintended side effects such as neuropathic pain is necessary before stem cell transplantation therapy after SCI.

• Korean Journal of Veterinary Research
• /
• v.41 no.1
• /
• pp.99-104
• /
• 2001

To determine if micronucleus (MN) assay could be used to predict the absorbed dose of victims after accidental radiation exposure, we carried out to assess the absorbed dose depending on the numerical changes of MN in human peripheral blood lymphocytes after $^{60}Co\;{\gamma}-rays$ exposure in the range of 0.25 to 1 Gy, respectively. The MNs were observed at very low doses, and the numerical changes according to doses. Satisfactory dose-effect calibration curve is observed after low dose irradiation of human lymphocytes in vitro. When plotting on a linear scale against radiation dose, the line of best fit was $Y=(0.02{\pm}0.0009)+(0.033{\pm}0.010)D+(0.012{\pm}0.012)D^2$. The dose-response curve for MN induction immediately after irradiation was linear-quadratic and has a significant relationship between the frequencies of MN and dose. These data show a trend towards increase of the numbers of MN with increasing dose. The number of MN in lymphocytes that were observed in the control group is $0.1610{\pm}0.0093/cell$. Accordingly, MN assay in human peripheral lymphocytes could be a useful in viva model for studying radio-protective drug sensitivity or screening test, microdosimertic indicator and radiation-induced target organ injury. Since MN assay is simple, rapid and reproducible, it will also be a biodosimetric indicator for individual dose assessment after accidental exposure.

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.29 no.6
• /
• pp.467-474
• /
• 2015

Allergic rhinitis is a growing tendency to increase. Following this tendency, allergic rhinitis is lively studied also in Korean oriental medicine. Bupleuri Radix (BR) has been used for many inflammatory diseases, but experimental backgrounds are not enough to treat allergic rhinitis. So in this study, effects of BR on OVA-induced allergic rhinitis model of BALB/c mice were examined. Thirty two BALB/c mice are equally devided into four groups; control group, OVA group, OVA+BR group, OVA+Cet group. The OVA, OVA+BR and OVA+Cet groups were induced allergic rhinitis by sensitizing to OVA. And then saline solution included BR (10.6 mg/kg body weight) was administered to the OVA+BR group orally. The number of nasal rubbing and nasal sneezing was evaluated for 10 days and later serological and histological changes were analyzed. Serological analysis included the serum levels of cytokines and chemokines (IL-4, IL-5, IL-12, MCP-1, MIP-2), total IgE and OVA-specific IgE levels in serum. Histological analysis included thickness of nasal septum, eosinophil counts changes of nasal mucosa, infiltration of eosinophil in nasal mucosa and histological changes of nasal mucosa. The number of nasal rubbing and nasal sneezing was significantly decreased in the OVA+BR group. The serum levels of IL-4, IL-5, MCP-1, MIP-2 were significantly decreased in the OVA+BR group but the serum levels of IL-1β had not significance. Total IgE and OVA-specific IgE levels in serum were decreased in the OVA+BR group, but total IgE levels in serum had only significance. Thickness of nasal septum, eosinophil counts of nasal mucosa and infiltration of eosinophil in nasal mucosa were significantly decreased in the OVA+BR group. From the results of this study, we think that BR has an effect on improvement of allergic rhinitis by improving nasal rubbing and nasal sneezing, reducing histological changes of nasal mucosa and infiltration of eosinophil in nasal mucosa, inhibiting increasing of the serum levels of cytokines, chemokines and total IgE.

• The Journal of Engineering Geology
• /
• v.25 no.3
• /
• pp.377-385
• /
• 2015

We constructed a model test apparatus to evaluate the dependence of the saturation velocity (V_s) in soils on rainfall intensity (I_R). The apparatus comprises a soil box, a rainfall simulator, and measuring sensors. The model grounds (60 cm × 50 cm × 15 cm) were formed by Joomunjin standard sand with a relative density of 75%. The rainfall simulator can control the rainfall intensity to reenact the actual rainfall in a soil box. Time Domain Reflectometer (TDR) sensors and tensiometers were installed in the soils to measure changes in the volumetric water content and matric suction due to rainfall infiltration. During the tests, the soil saturation was determined by raising the groundwater table, which was formed at the bottom of the soil box. [Please check that the correct meaning has been maintained.] The wetting front did not form at the ground surface during rainfall because the soil particles were uniform and the coefficient of permeability was relatively high. Our results show that the suction stress of the soils decreased with increasing volumetric water content, and this effect was most pronounced for volumetric water contents of 20%-30%. Based on a regression analysis of the relationship between rainfall intensity and the average saturation velocity, we suggest the following equation for estimating the saturation velocity in soils: V_savg (cm/sec) = 0.068I_R (mm/hr).