• Korean Journal of Exercise Nutrition
• /
• v.16 no.2
• /
• pp.65-71
• /
• 2012

Oxygen is the final acceptor of electron transport from fat and carbohydrate oxidation, which is the rate-limiting factor for cellular ATP production. Under altitude hypoxia condition, energy reliance on anaerobic glycolysis increases to compensate for the shortfall caused by reduced fatty acid oxidation [1]. Therefore, training at altitude is expected to strongly influence the human metabolic system, and has the potential to be designed as a non-pharmacological or recreational intervention regimen for correcting diabetes or related metabolic problems. However, most people cannot accommodate high altitude exposure above 4500 M due to acute mountain sickness (AMS) and insulin resistance corresponding to a increased levels of the stress hormones cortisol and catecholamine [2]. Thus, less stringent conditions were evaluated to determine whether glucose tolerance and insulin sensitivity could be improved by moderate altitude exposure (below 4000 M). In 2003, we and another group in Austria reported that short-term moderate altitude exposure plus endurance-related physical activity significantly improves glucose tolerance (not fasting glucose) in humans [3,4], which is associated with the improvement in the whole-body insulin sensitivity [5]. With daily hiking at an altitude of approximately 4000 M, glucose tolerance can still be improved but fasting glucose was slightly elevated. Individuals vary widely in their response to altitude challenge. In particular, the improvement in glucose tolerance and insulin sensitivity by prolonged altitude hiking activity is not apparent in those individuals with low baseline DHEA-S concentration [6]. In addition, hematopoietic adaptation against altitude hypoxia can also be impaired in individuals with low DHEA-S. In short-lived mammals like rodents, the DHEA-S level is barely detectable since their adrenal cortex does not appear to produce this steroid [7]. In this model, exercise training recovery under prolonged hypoxia exposure (14-15% oxygen, 8 h per day for 6 weeks) can still improve insulin sensitivity, secondary to an effective suppression of adiposity [8]. Genetically obese rats exhibit hyperinsulinemia (sign of insulin resistance) with up-regulated baseline levels of AMP-activated protein kinase and AS160 phosphorylation in skeletal muscle compared to lean rats. After prolonged hypoxia training, this abnormality can be reversed concomitant with an approximately 50% increase in GLUT4 protein expression. Additionally, prolonged moderate hypoxia training results in decreased diffusion distance of muscle fiber (reduced cross-sectional area) without affecting muscle weight. In humans, moderate hypoxia increases postprandial blood distribution towards skeletal muscle during a training recovery. This physiological response plays a role in the redistribution of fuel storage among important energy storage sites and may explain its potent effect on changing body composition. Conclusion: Prolonged moderate altitude hypoxia (rangingfrom 1700 to 2400 M), but not acute high attitude hypoxia (above 4000 M), can effectively improve insulin sensitivity and glucose tolerance for humans and antagonizes the obese phenotype in animals with a genetic defect. In humans, the magnitude of the improvementvaries widely and correlates with baseline plasma DHEA-S levels. Compared to training at sea-level, training at altitude effectively decreases fat mass in parallel with increased muscle mass. This change may be associated with increased perfusion of insulin and fuel towards skeletal muscle that favors muscle competing postprandial fuel in circulation against adipose tissues.

• Korean Journal of Clinical Laboratory Science
• /
• v.46 no.3
• /
• pp.106-110
• /
• 2014

Obstructive sleep apnea-hypopnea (OSAH) is known to be related to nocturnal blood pressure (BP) and hypertension. The aim of this study was to evaluate the prevalence of hypertension according to the apnea-hypopnea grading. A total of 2,210 adults with snoring and obstructive sleep apnea were referred to our sleep center from July 2009 to May 2013. Clinical blood pressure (BP) was measured before sleeping (bedtime BP) and immediately after waking up in the next morning (morning BP). Subjects were classified into four groups based on the apnea-hypopnea index (AHI) from PSG as follows: control group (n=470) simple snoring and with AHI<5; mild group (n=577) with $AHI{\geq}5$ and <15; moderate group (n=508) $AHI{\geq}15$ and <30; and severe group (n=655) with $AHI{\geq}30$. The differences and correlations between BP and PSG parameters according to the AHI groups were analyzed. Patient's were classified as nomentensive (blood pressure <120/90 mmHg, n=700), prehypertensive (blood pressure < $140-120{\leq}mmHg$, n=1297) hypertensive (blood pressure ${\geq}140/90mmHg$, n=214) according to the office blood pressure measurements. The comparison of sleep parameters showed that OSA groups had a significantly higher stage N1 (control group vs. moderate OSA, severe OSA; $66.4{\pm}30.7$ vs. $85.5{\pm}36.6$, $128.4{\pm}57.3$, p<0.001) and total arousal number (control vs. moderate OSA, severe OSA; $110.7{\pm}47.7$ vs. $150.8{\pm}56.6$, $236.6{\pm}95.8$, p<0.001) compared to control group. The comparison of sleep parameters showed that OSA groups had a significantly lower stage N2 (control group vs. moderate OSA, severe OSA; $172.6{\pm}47.2$ vs. $150.7{\pm}50.5$, $120.3{\pm}57.4$, p<0.001), stage N3 (control group vs. moderate OSA, severe OSA; $38.4{\pm}33.4$ vs. $27.4{\pm}26.0$, $56.1{\pm}27.5$, p<0.001), REM (control group vs. moderate OSA, severe OSA; $64.3{\pm}25.5$ vs. $56.1{\pm}27.5$, $47.3{\pm}25.9$, p<0.001) and mean SaO2% (control group vs. moderate OSA, severe OSA; $90.0{\pm}3.5$ vs. $82.5{\pm}5.5$, $70.0{\pm}8.8$, p<0.001) compared to control group. The Apnea-hypopnea index was significantly higher in OSA groups, increased systolic and diastolic blood pressure than in the nomentensive group (bed time systolic pressure vs. AHI; <120 vs. 120-139, 140-159, >159; $17.5{\pm}18.6$ vs. $24.9{\pm}21.0$, $31.0{\pm}25.7$, $42.3{\pm}31.7$, p<0.001), (bed time diastolic pressure vs. AHI; 60-79 vs. 80-89, 90-99, >99; $19.3{\pm}19.7$ vs. $22.4{\pm}20.3$, $29.8{\pm}23.3$, $38.8{\pm}28.5$, p<0.001). AHI was positively correlated with morning systolic pressure, diastolic pressure, bed time systolic pressure and diastolic pressure (r=0.314, 0.279, 0.233 and 0.200, respectively, p<0.001). We conclude that BMI, Age, neck circumference and AHI increase with the blood pressure.

• The Bulletin of The Korean Astronomical Society
• /
• v.24 no.1
• /
• pp.40-40
• /
• 1999

• Clinical and Experimental Pediatrics
• /
• v.63 no.6
• /
• pp.217-218
• /
• 2020

• Korean Circulation Journal
• /
• v.52 no.12
• /
• pp.887-889
• /
• 2022

• Korean Circulation Journal
• /
• v.52 no.12
• /
• pp.901-902
• /
• 2022

• Advances in Traditional Medicine
• /
• v.5 no.4
• /
• pp.316-321
• /
• 2005

Aristolochia bracteolata is being used in traditional medicine for a variety of ailments. Three successive and two crude extracts of its leaves were subjected for in vitro antioxidant activity using seven different methods. The successive ethyl acetate and crude methanol extracts have shown potent antioxidant activity in ABTS method with $IC_{50}$ values of $17.08\;{\pm}\;0.44\;and\;28.12\;{\pm}\;2.87\;{\mu}g/ml$, respectively. The crude methanol and successive chloroform extracts have shown moderate antioxidant activity in scavenging of hydroxyl radical by p-NDA method. All the extracts have shown moderate to low antioxidant activity by other methods.

• Journal of Korea Foundry Society
• /
• v.15 no.2
• /
• pp.156-163
• /
• 1995

Solidification of aluminum alloys under moderate pressures has been investigated. Interfacial heat transfer coefficient at the casting/mold interface varies with time after pouring the molten metal into the die cavity, and therefore plays an important role in determining solidification sequence. The heat transfer coefficients were evaluated by using an inverse problem method, based on the measured temperature distribution. The calculated heat transfer coefficients were used for solidification simulation in the squeeze casting process. The effects of applied pressure and positions of insulation in the mold have also been investigated on solidification microstructures and on the formation of macrosegregation of Al-4.5wt.%Cu alloys.

• Journal of Korean Physical Therapy Science
• /
• v.6 no.3
• /
• pp.117-123
• /
• 1999

The prognosis and result of treatment are influenced by associated cerebral handicaps. 38 cerebral palsied children in rehabilitation center were analized and neuromotor type severity associated defects, and their correlation were studied. The results were follows: 1. neuromotor type distribution was 65.78% of spasticity, 21.05% of athetoid, 2.63% of Ataxia, Tremor, and Rigidity, 5.26% of mixed type. 2. Mean values of I.Q, S.Q and M.Q were 84.3, 63.0 and 26.6 respectively, and percentages of strabismus, speech disturbance, shoulder abnormality, spine abnormality and hip abnormality were 26.3%, 81.5%, 5.2%, 52.6% and 15.9% respectively. 3. Significant differences were noted between each group of mild, moderate, and severe in S. Q, M. Q, and spine abnormality and between moderate and severe group in speech disturbance.

• Journal of the Korean Society of Clothing and Textiles
• /
• v.22 no.4
• /
• pp.469-476
• /
• 1998

The natural dyestuff(chestnut dye) was manufactured from chestnut hulls by boiling in 0.5 NaOH solution and powdering in freeze dryer. To investigate the dyeability and color fastness, cotton, wool, silk and nylon fabrics were dyed under several conditions using the manufactured chestnut dye. Dyeing operation was carried in acidic dyebath of pH 4-5 because the chestnut dye is anionic. Dyeabilities on wool, silk and nylon fabrics were good, especially nylon fabrics were dyed deeper than others. But dyeability on cotton fabrics was not good. All the dyed fabrics showed excellent color fastness to crocking. Color fastness to laupdering of them were moderate to good. Also light fastness of them were moderate to good except nylon. The light fastness of dyed nylon fabrics was as poor as grade 1. But they could be improved to grade 4 by aftertreatment with gallic acid.