• The Korean Journal of Physiology and Pharmacology
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• v.15 no.3
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• pp.179-187
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• 2011

Regulation of B cell receptor (BCR)-induced $Ca^{2+}$ signaling by CD40 co-stimulation was compared in long-term BCR-stimulated immature (WEHI-231) and mature (Bal-17) B cells. In response to long-term pre-stimulation of immature WEHI-231 cells to ${\alpha}$-IgM antibody (0.5~48 hr), the initial transient decrease in BCR-induced $[Ca^{2+}]_i$ was followed by spontaneous recovery to control level within 24 hr. The recovery of $Ca^{2+}$ signaling in WEHI-231 cells was not due to restoration of internalized receptor but instead to an increase in the levels of $PLC{\gamma}2$ and $IP_3R-3$. CD40 co-stimulation of WEHI-231 cells prevented BCR-induced cell cycle arrest and apoptosis, and it strongly inhibited the recovery of BCR-induced $Ca^{2+}$ signaling. CD40 co-stimulation also enhanced BCR internalization and reduced expression of $PLC{\gamma}2$ and $IP_3R-3$. Pre-treatment of WEHI-231 cells with the antioxidant N-acetyl-L-cysteine (NAC) strongly inhibited CD40-mediated prevention of the recovery of $Ca^{2+}$ signaling. In contrast to immature WEHI-231 cells, identical long-term ${\alpha}$-IgM pre-stimulation of mature Bal-17 cells abolished the increase in BCR-induced $[Ca^{2+}]_i$, regardless of CD40 co-stimulation. These results suggest that CD40-mediated signaling prevents antigen-induced cell cycle arrest and apoptosis of immature B cells through inhibition of sustained BCR-induced $Ca^{2+}$ signaling.

• Asia pacific journal of information systems
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• v.16 no.2
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• pp.183-203
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• 2006

Firms are increasingly adopting online communities-of-practice (CoPs) with strong managerial support in hopes of promoting knowledge sharing and creation within the organization. Excessive managerial concern and sponsoring, however, could harm the spontaneity of CoP participants, which is one of the pivotal characteristics of virtual communities, and in the end, have negative impact on their smooth operation. In this regard, this study examines the factors which affect the stimulation of CoPs and explores the difference in their operating mechanisms under two differing organizational structural settings by the existence of a sponsor. By analyzing 133 samples of CoPs in a globally leading company, this study found that the existence of a sponsor designated by the organization, has serious influence on the working of CoPs, That is, leaders' enthusiasm and the level of off-line activities are critical factors for the stimulation of CoPs which have no sponsor, while in case of CoPs that have their sponsors, neither leaders' enthusiasm nor the level of off-line activities are significantly related to the stimulation of CoPs. At the same time, the performance of CoPs which have their sponsors was found significantly higher than that of CoPs which have no sponsor. These results indicate that firms need to pay special attention to organizational sponsorship when introducing CoPs within their organizations.

• IMMUNE NETWORK
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• v.9 no.4
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• pp.127-132
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• 2009

Background: Toll-like receptors (TLRs) play a fundamental role in innate immunity through their capacity to recognize pathogen-associated molecular patterns. Also, TLRs that are expressed in T cells are reported to function as co-stimulatory receptors. However, the functional capacity of TLRs on CD4 T and CD8 T cells has not been directly compared. Here we compared CD4 and CD8 T cell responses to TLR2 ligand plus TCR-mediated stimulation. Methods: TLR2 expression was analyzed on T cell subsets under naive and alloantigen-primed conditions. We analyzed the effects of TLR2 co-stimulation on proliferation and survival of T cell subsets in vitro when stimulated with soluble anti-CD3 in the presence or absence of synthetic ligand $Pam_3CSK_4$. Results: TLR2 expression on CD8 T cells was induced following activation; this expression was much higher than on CD4 T cells. Thus, the molecule was constitutively expressed on Listeriaspecific memory CD8 T cells. Based on these expression levels, proliferation and survival were markedly elevated in CD8 T cells in response to the TLR2 co-stimulation by $Pam_3CSK_4$ compared with those in CD4 T cells. Conclusion: Our data show that TLR2 co-stimulation is more responsible for proliferation and survival of CD8 T cells than for that of CD4 T cells.

• Asian-Australasian Journal of Animal Sciences
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• v.16 no.8
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• pp.1218-1223
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• 2003

The effects of type (high and low voltages) and time (3, 40 and 60 min postmortem) of stimulation on drip loss and meat color at 24 h post-mortem were determined on M. longissimus dorsi of 38 crossbred steers and heifers. In addition, the effect of pH early postmortem (70 min postmortem) on the rate and extend of meat tenderization was examined. Either high or low voltage stimulation at 3 min showed a tendency for faster pH decline (p=0.052) and higher drip loss (p=0.08), and improved the color dimensions of L*, a* and b* (p<0.01), compared to stimulation at 40 min. This was equivalent to approximately one unit of an AUSMEAT color chip. On the other hand, although there were significant differences in pH decline between high voltage stimulation at 40 and 60 min, and between low voltage stimulation at 40 min and control sides, drip loss and meat color did not differ significantly (p>0.05). The results suggested that early application of stimulation, regardless of type of stimulation, improved overall meat color at 24 h postmortem through its effect on faster glycolysing rate. However, if the pH decline was moderate, the benefit of electrical stimulation on meat color was not apparent. An intermediate pH decline resulted in the lowest shear force. Due to differential ageing rates the optimum pH at 70 min postmortem increased with ageing time from 5.96, 6.07, 6.12 and 6.14 for 1, 3, 7 and 14 days postmortem, respectively. This implied that a small difference in the rate of pH decline was important, especially carcasses stimulated for very early postmortem, and the optimum rate of pH decline varied with intended ageing period. The study suggests that the beneficial or adverse effects of electrical stimulation on drip loss, meat color and tenderness is determined by the rate of pH decline, rather than by stimulation treatment and time of application per se.

• The Journal of Korean Physical Therapy
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• v.23 no.6
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• pp.71-76
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• 2011

Purpose: We investigated a better method to enhance the vestibular system including balancing by comparing the vestibular stimulation exercise (VSE) and galvanic vestibular stimulation (GVS). Methods: The study was performed with 40 subjects randomized into four groups, including a control group, a VSE group, a GVS group, and a VSE with GVS group. The subjects of VSE performed a forward and backward roll, a right side and left side roll, and an equilibrium board in vestibular stimulation training. GVS was applied for 10 minutes and the cathode and anode side were then changed and GVS was then applied for the remaining 10 minutes. GVS was applied for 20 minutes to the subjects of this group after completion of the VSE program. Results: In the control group, all conditions were significantly decreased (p<0.05) compared to the VSE with GVS group. Also, the center of pressure (CoP) surface was more significantly decreased (p<0.01) and the CoP speed was significantly decreased in the one legged stance (p<0.05) in the control group compared to the GVS group. Conclusion: These findings suggested that GVS training increases balance ability in a narrow width. VSE with GVS training is therefore recommend as the superior method. Using GVS or VSE with GVS training is considered to clinically improve balance ability by stimulating the vestibular system.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2206-2208
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• 2003

This paper is performed to find the effects on body heat by stimulating the skin with the heat of a moxibustion cauterizer and the Artemisia-lotion which cause the extension of the blood vessel. The Artemisia-lotion is made by extracting the vasodilator and antioxidant compounds from the $Artemisia-CH_2Cl_2$ fraction. The moxibustion cauterizer is constructed with a DC power supply and 3 heating electrodes with PTC(Positive Temperature Coefficients) thermistor. The stimulation temperature level of the moxibustion cauterizer is $45^{\circ}C\;-48^{\circ}C$. We gave the subjects the following stimulating conditions; only heat stimulation, only Artemisia -lotion stimulation, and both stimulations. The measurement of body heat was performed with a infrared thermography system . Finally we could estimate the effects of a betterment of circulation of the blood from $Artemisia-CH_2Cl_2$ fraction.

• Advances in Traditional Medicine
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• v.5 no.3
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• pp.195-200
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• 2005

In order to examine the effectiveness of moxibustion stimulation for climacteric disturbance, we administered moxibustion stimulation to ovariectomized (OVX) rats, and compared the tail surface temperature, laboratory parameters, and the level of locomotor activity with those of untreated rats. Twenty-four female Wistar rats (8 weeks old, 160 - 180 g) were divided into three groups. The rats in the OVX-M group underwent moxibustion stimulation after ovariectomy. The rats in the OVX-C group underwent ovariectomy but did not receive moxibustion stimulation. The rats in the Normal group received neither ovariectomy nor moxibustion stimulation. The level of locomotor activity was determined by a metabolism measuring system. The tail surface temperature was significantly lower in the OVX rats before moxibustion stimulation than in the Normal group. In the OVX rats before moxibustion stimulation, there was no clear difference in the level of locomotor activity between the active and resting phases, and the pattern of locomotor activity was irregular. After moxibustion stimulation, the tail surface temperature of the OVX-M group did not significantly differ from that of the Normal group, and the pattern of locomotor activity of the OVX-M group became diphasic with clear active and resting phases, similar to that observed in the Normal group. These results demonstrate that moxibustion stimulation is effective for the treatment of climacteric disturbance.

• Journal of Biomedical Engineering Research
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• v.32 no.2
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• pp.93-104
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• 2011

The purpose of this study was to investigate lower-limb joint torque of the two groups as it changed by somatosensory stimulation during the descent down three stairs of different heights and to describe the difference between the two groups, which are young people group and elderly people group. Subjects of each groups climbed down a stair at four stimulation conditions, which are non-stimulation, tibialis anterior tendon stimulation, achilles tendon stimulation, tibialis anterior - achilles tendon stimulation. Motion capture data were collected using 3D optoelectric motion tracking system that utilizes active infrared LEDs, near infrared sensor and force plate. The obtained motion capture data was used to build 3D computer simulation model. The results show that lower-limb joint torque of the two groups changed with somatosensory stimulation as they descended the stairs and the joint torque of the two groups differed from each other.

• Journal of Biomedical Engineering Research
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• v.30 no.6
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• pp.521-528
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• 2009

This study is about to evaluation of postural stability according to characteristics of electrical stimulation on the ankle muscles. We measured body sway(center of pressure, COP) when various parameters of electrical stimulation was applied to ankle muscles in stable and unstable posture. Subjects consisted of 10 young adults, and electrical stimulation was delivered on right and left of tibialis anterior and Achilles tendon. The body sway was measured during electrical stimulation of three duty cycle and frequencies in stable posture and three amplitudes of sensory threshold in unstable posture. Consequently, the COP Shift is higher during electrical stimulation of 1/30(duty ratio) and 100Hz(frequency) in stable posture. In unstable posture, 100% amplitude of sensory threshold induced postural stability. These findings are important for the rehabilitation system of postural stability and the use of electrical stimulation as somatosensory information.

• Journal of Biomedical Engineering Research
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• v.45 no.1
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• pp.37-42
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• 2024

In this study, we explored the possibility of using sympathetic skin response (SSR), a type of electrodermal activity (EDA), as a method of evaluating a subject's responsiveness to physical or psychological stimulation. To provide physical and psychological stimulation, walking on an acupressure plate and a roller coaster virtual reality experience wearing an HMD (head mounted display) were used. Walking on an acupressure plate significantly increased the SSR signal compared to walking on the bare floor. Additionally, it was observed that the SSR response significantly increased while the subject was wearing an HMD and experiencing a roller coaster compared to the resting state of sitting on a chair. The SSR response to physical or psychological stimulation increased in all subjects, but the degree of reactivity differed. These experimental results suggested that sympathetic skin response (SSR) is a useful tool as a biosignal that can be used to evaluate the human body's responsiveness to physical stimulation or psychological stimulation using virtual reality.