• Journal of Pharmacopuncture
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• v.6 no.3
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• pp.91-106
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• 2003

Objectives : The aim of this study was to examine the effects of electroacupuncture(EA) at the PC6(Naegwan) and the TE5 (Oegwan) on nounal humans using power spectral analysis. Methods : EEG power spectrum exhibit site-specific and state-related differences in specific frequency bands. In this study, power spectrum was used as a measure of complexity. 30 channel EEG study was carried out in 30 subjects(30 males ; age=23.7 years). Results : In ${\alpha}$(alpha) band, the power values at F7 channels(p<0.05) during the PC6-acupoint treatment were significantly were decreased. In ${\beta}$(beta) band, the power values at Fp1, Fz, TT1, T5, P3, P4, Po1, P02, O1, Oz, O2 channels(p<0.05) during the non-acupoint treatment and at Fp1, F4, F8 channels(p<0.05) during the TE5-acupoint treatment significantly were increased. In ${\theta}$(theta) band, the power values at Fp1 channels(p<0.05) during the non-acupoint treatment and at Oz channels(p<0.05) the TE5-acupoint treatment significantly were increased. but, the power values at F7 channels(p<0.05) during the non-acupoint treatment were significantly were decreased. In ${\delta}$(delta) band, the power values at TCP1, TCP2, CP1, T5 channels(p<0.05) during PC6-acupoint treatment were increased and the power values at F7, TT2 channels(p<0.05) during non-acupoint treatment were increased. but, the power values at the TE5-acupoint treatment significantly was decreased than the before-acupuncture treatment.

• Journal of Haehwa Medicine
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• v.14 no.1
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• pp.141-147
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• 2005

The most fundamental and important medical treatment is science of acupuncture and moxibution, which is based on twelve channels theory. Meridian is a pathway that conveys material and energy in a human body. Twelve channels are divided into channels of hand & foot, channels of yin & yang. Yang channels are divided into taiyang, yangming, shaoyang, yin channels are divided into taiyin, shaoyin, jueyin. These are referred to twelve channels, and this theory is being used for diagnosis and test in oriental medicine. Meridian-doin-tajiquan is born, combining taijiquan which is recently handed down from China and Korean traditional method for health protection and treatment in ancient times and twelve channels, three yin & yang theory. I report this because meridian-doin-tajiquan which is non-medical and non-invasive way can be used in the treatment of disease, just like three yin & yang theory, the heart of the meridian theory, and Gehapchu theory are adjusted in the clinical science of acupuncture and moxibution. And I report this because I could mater the appropriateness of the traditional theory and I believed this corresponded with it, training myself by meridian-din-tajiquan. It is considered that this will be used in the treatment of pain disease of muscles and joints system and the diabetes, hypertension, obesity caused by stress in the near future.

• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.215-219
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• 2007

Small and large conductance $Ca^{2+}$-activated $K^+(SK_{Ca}\;and\;BK_{Ca})$ channels are implicated in the modulation of neuronal excitability. We investigated how changes in peripheral $K_{Ca}$ channel activity affect mechanical sensitivity as well as the afferent fiber type responsible for $K_{Ca}$ channel-induced mechanical sensitivity. Blockade of $SK_{Ca}$ and $BK_{Ca}$ channels induced a sustained decrease of mechanical threshold which was significantly attenuated by topical application of capsaicin onto afferent fiber and intraplantar injection of 1-ethyl-2-benzimidazolinone. NS1619 selectively attenuated the decrease of mechanical threshold induced by charybdotoxin, but not by apamin. Spontaneous flinching and paw thickness were not significantly different after $K_{Ca}$ channel blockade. These results suggest that mechanical sensitivity can be modulated by $K_{Ca}$ channels on capsaicin-sensitive afferent fibers.

• Journal of Communications and Networks
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• v.5 no.2
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• pp.174-183
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• 2003

Space-Time (ST) codes are known to provide high transmission rates, diversity and coding gains. In this paper, a tight upper bound on the error probability of ST codes over rapid fading channels is presented. Moreover, ST codes suitable for rapid fading channels are presented. These codes are designed using the QPSK and 16-QAM signal constellations. The proposed codes are based on two different encoding schemes. The first scheme uses a single trellis encoder, whereas the second scheme uses the I-Q encoding technique. Code design is achieved via partitioning the signal space such that the design criteria are maximized. As a solution for the decoding problem of I-Q ST codes, the paper introduces a low-complexity decoding algorithm. Results show that the I-Q ST codes using the proposed decoding algorithm outperform singleencoder ST codes with equal complexity. The proposed codes are tested over fading channels with different interleaving conditions, where it is shown that the new codes are robust under such imperfect interleaving conditions.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.5C
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• pp.506-513
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• 2003

Most existing space-time coding (STC) schemes have been developed for flat fading channels. To obtain antenna diversity gain, they rely on channel state information (CSI) required at the receiver through channel estimation techniques. This paper proposes a new decision feedback decoding scheme for Alamouti-based space-time block coding (STBC) transmission over time-selective fading channels. In wireless channels, time-selective fading effects arise mainly due to Doppler shift and carrier frequency offset, Modelling the time-selective fading channels as the first-order Gauss-Markov processes, we use recursive algorithms such as Kalman filtering, LMS and RLS algorithms for channel tracking. The proposed scheme consists of the symbol decoding stage and channel tracking algorithms. Computer simulations confirm that the proposed scheme shows the better performance and robustness to time-selectivity.

• Reproductive and Developmental Biology
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• v.28 no.3
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• pp.147-153
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• 2004

The oocyte and its surrounding granulosa cells co-exist in a closed compartment called a follicle, although they receive many signals from other parts of the body. It is well established that the intercellular communications between the oocyte and granulosa cells are required for normal oocyte development and ovulation during folliculogenesis. Gap junctions are intercellular channels allowing the direct transmission of ions and small molecules between coupled cells. Several lines of studies have shown that multiple connexins (Cx, subunits of gap junction) are expressed in mammalian ovarian follicles. Among them, two major connexins Cx37 and Cx43 are expressed in different manner. While the gap junction channels formed by Cx37 are localized between the oocyte and encompassing granulosa cells, the intercellular channels by Cx43 are located between granulosa cells. In this review, I will summarize the general properties of gap junction channels and discuss their possible formation (or compatibility) of intercellular channels formed by the oocyte and granulosa cells.

• Biomolecules & Therapeutics
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• v.26 no.5
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• pp.439-445
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• 2018

T-type calcium channels are low voltage-activated calcium channels that evoke small and transient calcium currents. Recently, T-type calcium channels have been implicated in neurodevelopmental disorders such as autism spectrum disorder and neural tube defects. However, their function during embryonic development is largely unknown. Here, we investigated the function and expression of T-type calcium channels in embryonic neural progenitor cells (NPCs). First, we compared the expression of T-type calcium channel subtypes (CaV3.1, 3.2, and 3.3) in NPCs and differentiated neural cells (neurons and astrocytes). We detected all subtypes in neurons but not in astrocytes. In NPCs, CaV3.1 was the dominant subtype, whereas CaV3.2 was weakly expressed, and CaV3.3 was not detected. Next, we determined CaV3.1 expression levels in the cortex during early brain development. Expression levels of CaV3.1 in the embryonic period were transiently decreased during the perinatal period and increased at postnatal day 11. We then pharmacologically blocked T-type calcium channels to determine the effects in neuronal cells. The blockade of T-type calcium channels reduced cell viability, and induced apoptotic cell death in NPCs but not in differentiated astrocytes. Furthermore, blocking T-type calcium channels rapidly reduced AKT-phosphorylation (Ser473) and $GSK3{\beta}$-phosphorylation (Ser9). Our results suggest that T-type calcium channels play essential roles in maintaining NPC viability, and T-type calcium channel blockers are toxic to embryonic neural cells, and may potentially be responsible for neurodevelopmental disorders.

• Proceedings of the Korean Biophysical Society Conference
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• 2002.06b
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• pp.20-21
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• 2002

The inflow of Ca$\^$2＋/ through voltage-activated T-type calcium channels (T-channels) regulates a variety of cellular functions including neuronal excitability, cardiac pacemaker activity, hormone secretion, smooth muscle contraction, and fertilization. Not only are T-channels enormously important for the normal operation of cells, they also playa critical role in pathophysiological conditions such as cardiac hypertrophy and absence epilepsy.(omitted)

• Development and Reproduction
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• v.21 no.1
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• pp.11-18
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• 2017

Potassium channels, the largest group of pore proteins, selectively regulate the flow of potassium ($K^+$) ions across cell membranes. The activity and expression of $K^+$ channels are critical for the maintenance of normal functions in vessels and neurons, and for the regulation of cell differentiation and maturation. However, their role and expression in stem cells have been poorly understood. In this study, we isolated perivascular stem cells (PVCs) from human umbilical cords and investigated the expression patterns of big-conductance $Ca^{2+}$-activated $K^+$ ($BK_{Ca}$) and voltage-dependent $K^+$ ($K_v$) channels using the reverse transcription polymerase chain reaction. We also examined the effect of high glucose (HG, 25 mM) on expression levels of $BK_{Ca}$ and $K_v$ channels in PVCs. $K_{Ca}1.1$, $K_{Ca}{\beta}_3$, $K_v1.3$, $K_v3.2$, and $K_v6.1$ were detected in undifferentiated PVCs. In addition, HG treatment increased the amounts of $BK_{Ca}{\beta}_{3a}$, $BK_{Ca}{\beta}_4$, $K_v1.3$, $K_v1.6$, and $K_v6.1$ transcripts. These results suggested that ion channels may have important functions in the growth and differentiation of PVCs, which could be influenced by HG exposure.

• The Korean Journal of Physiology and Pharmacology
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• v.21 no.4
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• pp.415-421
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• 2017

We investigated the inhibitory effect of escitalopram, a selective serotonin reuptake inhibitor (SSRI), on voltage-dependent $K^+$ (Kv) channels in freshly separated from rabbit coronary arterial smooth muscle cells. The application of escitalopram rapidly inhibited vascular Kv channels. Kv currents were progressively inhibited by an increase in the concentrations of escitalopram, suggesting that escitalopram inhibited vascular Kv currents in a concentration-dependent manner. The $IC_{50}$ value and Hill coefficient for escitalopram-induced inhibition of Kv channels were $9.54{\pm}1.33{\mu}M$ and $0.75{\pm}0.10$, respectively. Addition of escitalopram did not alter the steady-state activation and inactivation curves, suggesting that the voltage sensors of the channels were not affected. Pretreatment with inhibitors of Kv1.5 and/or Kv2.1 did not affect the inhibitory action of escitalopram on vascular Kv channels. From these results, we concluded that escitalopram decreased the vascular Kv current in a concentration-dependent manner, independent of serotonin reuptake inhibition.