• The Korean Journal of Physiology and Pharmacology
• /
• v.1 no.4
• /
• pp.457-466
• /
• 1997

The effects of DFMO or/and putrescine on the dexamethasone-induced apoptosis of CEM cells were studied to investigate the role of polyamines in anti-leukemic glucocorticoid action. Dexamethasone- induced apoptosis was preceded by significant decreases of cellular polyamine contents and putrescine uptake activity. But DFMO produced decreases of putrescine and spermidine contents and marked increase of putrescine uptake activity, but did not induce apoptosis. However, dexamethasone and DFMO, respectively, induced $G_1-arrest$ in cell cycle and hypophosphorylation of pRb, resulting in the increase of $G_1$ to S ratio and decrease of CEM cell count. DFMO enhanced the dexamethasone-induced apoptosis and $G_1-arrest$. On the other hand, putrescine little affected the apoptotic and $G_1-arresting$ activities of dexamethasone, but almost suppress the effects of DFMO and also the DFMO-dependent enhancement of dexamethasone effects. These results suggested that the dexamethasone-induced apoptosis to be associated with pRb hypophosphorylation and $G_1-arrest$ in CEM cells might be ascribed to the concomitant decreases of cellular polyamine contents and putrescine uptake activity.

• Proceedings of the KOSOMBE Conference
• /
• v.1997 no.11
• /
• pp.323-326
• /
• 1997

In this study, we investigated the circardian rhythm of complexity of cardiac dynamics in humans. Dynamic 24-hour electrocardiographic recordings were obtained from 30 healthy ambulant subjects aged 41 to 50 years. or each recordings, normalized low frequency (0.04-0.1 hertz) and high frequency (>0.15 hertz) component are calculated. our different indexes obtained from separate algorithms of nonlinear dynamics - approximate entropy, correlation dimension, Lyapunov exponent and fractal dimension - were calculated. During early morning, low frequency component rose rapidly with concomitant withdrawl of high frequency component. All the our indexes of nonlinear dynamics showed remarkably same circardian rhythm: an early morning dip preceded by a steep decline during late night, a gradual recovery during evening and a peak around midnight. These data indicate that the simultansous losses of all of the our different mechanisms of nonlinear control of heart rate during early morning, concomitent with the surge of symapathetic activity and reduction of vagal activity, may contribute to the increased incidence of cardiovascular events during morning hours.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
• /
• 2011.10a
• /
• pp.711-716
• /
• 2011

Today, high-speed trains enjoy wide acceptance as fast, convenient and environment-friendly means of transportation. However, increase in the speed of the train entails a concomitant increase in the aerodynamic noise, adversely affecting the passenger comfort. At the train speed exceeding 300 km/h, the effects of turbulent flows and vortex sheddding are greatly amplified, contributing to a significant increase in the aerodynamic noise. Drawing a biomimetic analogy from low-noise flight of owl, a method to reduce aerodynamic noise at inter-coach space of high-speed trains is investigated. The proposed method attempts to achieve the noise reduction by modifying the turbulent flow and vortex shedding characteristics at the inter-coach space. To determine the aerodynamic noise at various train speeds, wind tunnel testing and numerical CFD (Computational Fluid Dynamics) simulation for the basic inter-coach spacing model are carried out, and their results compared. The simulation and experimental results reveal that there are discrete frequency components associated with turbulent air flow at constant intervals in the frequency domain

• Journal of Physiology & Pathology in Korean Medicine
• /
• v.25 no.3
• /
• pp.417-424
• /
• 2011

Ketoconazole (KET) is an antifungal drug with a broad spectrum of activity that also induces reproductive toxicity in humans and animals. KET inhibits C17-20 lyase which blocks the conversion of 17 ${\alpha}$-hydroxyprogesterone to androstenedione. The effect of Cuscutae semen(CS) extract against KET-induced testicular damage was evaluated in male rats. CS extract was administered orally (100 and 200 mg/kg) for 26 days. Three weeks after CS extract administration, KET was CS-administered intraperitoneally at a dose of 100 mg/kg once a day for 5 days. KET-induced reproductive toxicity was associated with clear reductions of the weights of testes and epididymides, sperm indices and serum testosterone levels. In addition, marked oxidative damage to testicular lipids and alterations of natural antioxidant enzymes were reported in association with KET toxicity. Most of the KET-induced effects were greatly decreased with the concomitant application of CS extract. This study suggests a protective role of Cuscutae semen extract that could be attributed to its antioxidant properties.

• Parasites, Hosts and Diseases
• /
• v.50 no.4
• /
• pp.281-286
• /
• 2012

Helminthic infections afflict over 1.5 billion people worldwide, while Mycobacterium tuberculosis infects one third of the world's population, resulting in 2 million deaths per year. Although tuberculosis and helminthic infections coexist in many parts of the world, and it has been demonstrated that the T-helper 2 and T-regulatory cell responses elicited by helminths can affect the ability of the host to control mycobacterial infection, it is still unclear whether helminth infections in fact affect tuberculosis disease. In this review article, current progress in the knowledge about the immunomodulation induced by helminths to diminish the protective immune responses to bacille Calmette-Guerin vaccination is reviewed, and the knowledge about the types of immune responses modulated by helminths and the consequences for tuberculosis are summarized. In addition, recent data supporting the significant reduction of both M. tuberculosis antigen-specific Toll-like receptor (TLR) 2 and TLR9 expression, and pro-inflammatory cytokine responses to TLR2 and TLR9 ligands in individuals with M. tuberculosis and helminth co-infection were discussed. This examination will allow to improve understanding of the immune responses to mycobacterial infection and also be of great relevance in combating human tuberculosis.

• Journal of Photoscience
• /
• v.5 no.1
• /
• pp.17-22
• /
• 1998

Changes of chlorophyll fluorescence and xanthophyll cycle pigment contents in maize leaves were investigated dunng desiccation in darkness or in the light. In darkness, a drastic dehydration of detached maize leaves down to 50% relative water content (RWC) affected photochemical efficiency of photosystem II (Fv/Fm) and pht)tochemical quenching (qP) only slightly. In contrast, desiccation in the light with a moderate intensity led to a pronounced reduction in Fv/Fm with a Fo quenching when RWC was greater than 70%. This reduction in Fv/Fm could be recovered in darkness under hutrod condition. In leaves with RWC below 70%, significant reduction in Fv/Fm was accompanied by an increase of Fo, which could not be reversed within 5 h in darkness under humid condition. The nonphotochemical quenching increased during desiccation in the light with a concomitant rise in zeaxanthin at the expense of violaxanthin. Pretreatment with dithiothreitol (DTT), an inhibitor of zeaxanthin synthesis, inhibited the development of nonphotochemical quenching and prevented the xanthophyll interconversion during desiccation in the light. These results suggest that even light with a moderate intensity becomes excessive under dehydration and zeaxanthin-associated photoprotection of photosynthetic apparatus against photodamage is involved, but the protection is not complete against severe desiccation.

• Journal of Chest Surgery
• /
• v.27 no.3
• /
• pp.187-190
• /
• 1994

Between March, 1989, and August, 1993, 10 patients underwent aortocoronary bypass surgery concomittant with cardiac valve replacement. They were 6 men and 4 women, the age ranging from 47 to 64. 7 patients underwent single valve replacement and 2 patients underwent double valve replacement, Another one patient underwent only CABG one year after valve replacement and he had no evidence of prosthetic valve failure. Total number of graft vessels were.15,14 were saphenous venous grafts and 1 was internal mammary artery graft. Dyspnea on exertion was frequent symptom and was found in all patients. 8 patients presented stable angina, only 1 patient presented postinfarct angina and another 1 patient presented no angina symptom. The graft was placed prior to valve replacement and periods of myocardial ischemia were kept at a minimum by maintaining coronary perfusion throughout operation. Postoperative course was uneventful and there was no hospital mortality, as was supported by many reports, it is our opinion that simultaneous valve replacement and aortotomy bypass graft does not increase the risk of cardiac valve replacement substantially.

• Journal of Chest Surgery
• /
• v.50 no.1
• /
• pp.41-43
• /
• 2017

A 38-year-old female patient with a history of tetralogy of Fallot repair at 10 years of age underwent pulmonary valve replacement with a mechanical prosthesis, tricuspid annuloplasty, and right ventricular outflow tract cryoablation due to pulmonary regurgitation, tricuspid regurgitation, and multiple premature ventricular contractions with sustained ventricular tachycardia. After surgery, she had an uneventful postoperative course with arrhythmia monitoring. She was discharged without incident, and a follow-up Holter examination showed a decrease in the number of ventricular ectopic beats from 702 to 41.

• Journal of Chest Surgery
• /
• v.50 no.1
• /
• pp.50-53
• /
• 2017

A mixed infection of Mycobacterium abscessus subsp. abscessus (Mab) and Mycobacterium tuberculosis (MTB) in the lung is an unusual clinical manifestation and has not yet been reported. A 61-year-old woman had been treated for Mab lung disease and concomitant pneumonia, and was diagnosed with pulmonary tuberculosis (PTB). Despite both anti-PTB and anti-Mab therapy, her entire left lung was destroyed and collapsed. She underwent left pneumonectomy and received medical therapy. We were able to successfully treat her mixed infection by pneumonectomy followed by inhaled amikacin therapy. To the best of our knowledge, thus far, this is the first description of a mixed Mab and MTB lung infection.

• Proceedings of the Korean Vacuum Society Conference
• /
• 2010.08a
• /
• pp.128-128
• /
• 2010

In this study, we investigated the evolution and reduction of the surface roughness during the high-speed chemical dry thinning process of Si wafers. The direct injection of NO gas into the reactor during the supply of F radicals from NF3 remote plasmas was very effective in increasing the Si thinning rate, due to the NO-induced enhancement of the surface reaction, but resulted in the significant roughening of the thinned Si surface. However, the direct addition of Ar and N2 gas, together with NO gas, decreased the root mean square (RMS) surface roughness of the thinned Si wafer significantly. The process regime for the increasing of the thinning rate and concomitant reduction of the surface roughness was extended at higher Ar gas flow rates. In this way, Si wafer thinning rate as high as $20\;{\mu}m/min$ and very smooth surface roughness was obtained and the mechanical damage of silicon wafer was effectively removed. We also measured die fracture strength of thinned Si wafer in order to understand the effect of chemical dry thinning on removal of mechanical damage generated during mechanical grinding. The die fracture strength of the thinned Si wafers was measured using 3-point bending test and compared. The results indicated that chemical dry thinning with reduced surface roughness and removal of mechanical damage increased the die fracture strength of the thinned Si wafer.