• Journal of Korean Neurosurgical Society
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• v.50 no.6
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• pp.523-527
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• 2011

A 67-year-old woman presented for evaluation of severe coccygeal pain. The computed tomography scans and magnetic resonance imaging showed an asymmetric midline sacral tumor invading the right lower portion of S2. To preserve both S2 nerve roots and to obtain negative surgical margins, a modified mid-sacrectomy with an aid of a computed navigation system was performed. The sacral tumor was excised en bloc with negative tumor margins. Both S2 nerve roots were preserved and additional reconstruction was not necessary because of minimal resection of the sacroiliac joint. We report a case of a sacral chordoma which was excised en bloc with adequate surgical margins by a computer-assisted modified mid-sacrectomy. The computed navigation system may be a useful tool for tumor targeting and safe osteotomies in sacral tumor surgery via the posterior only approach.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.47 no.1
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• pp.60-68
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• 2010

In case of sensorineural hearing loss, auditory perception can be activated by electrical stimulation of the nervous system via electrode implanted into the cochlea or auditory nerve. Since the tonotopic map of the human auditory nerve has not been definitively identified, the recording of auditory nerve signal with microelectrode is desirable for determining the tonotopic map. This paper proposes the multi-channel analog front-end for auditory nerve signal detection. A channel of the proposed analog front-end consists of an AC coupling circuit, a low-power 4th-order Gm-C LPF, and a single-slope ADC. The AC coupling circuit transfers only AC signal while it blocks DC signal level. Considering the bandwidth of the auditory signal, the Gm-C LPF is designed with OTAs adopting floating-gate technique. For the channel-parallel ADC structure, the single-slope ADC is used because it occupies the small silicon area. Experimental results shows that the AC coupling circuit and LPF have the bandwidth of 100 Hz - 6.95 kHz and the ADC has the effective resolution of 7.7 bits. The power consumption per a channel is $12\;{\mu}W$, the power supply is 3.0 V, and the core area is $2.6\;mm\;{\times}\;3.7\;mm$. The proposed analog front-end was fabricated in a 1-poly 4-metal $0.35-{\mu}m$ CMOS process.

• Korean Journal of Acupuncture
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• v.29 no.4
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• pp.554-562
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• 2012

Objectives : The purpose of this research is to verify the effects of the Electromagnetic acupuncture(EMA) on BL15 by Pupil size variability(PSV) which is directly related to the activation of the Autonomic Nervous System. Methods : Thirty male subjects participated in this study and were divided into three groups(non-stimulated, manual acupuncture and EMA group). The size of pupil was measured in the cube place of $60{\times}60{\times}60$ cm in order to avoid the effect of the surrounding circumstances. All subjects were measured the size of left pupil about 200sec in the constant illumination. Results : We observed the decrease in PSV of manual acupuncture group compared to non-stimulation group, but it was not significant statistically(p>0.05). The decrease in PSV of EMA group was observed in comparison to two groups, and we confirmed the result of significant difference statistically(p<0.05). Conclusions : We concluded that EMA treatment method is enough to activate in the parasympathetic nerve system by inducing the biotransformation.

• Journal of Biomedical Engineering Research
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• v.22 no.5
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• pp.393-402
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• 2001

A computational model representative of cardiovascular circulation was built using 12 standard lumped compartments. Especially, both the baroreceptor reflex and the cardiopulmonary reflex control model were implemented to explain the auto-regulation of cardiovascular system. Another important aspect of this model is to utilize the impulse-response curve of the nerve system in transferring the impulse error signals to autonomous nerve system. For the verification of this model, we have computed the normal hemodynamic conditions and compared those with the clinical data. Then. hemodynamic shock of 20% hemorrhage to cardiovascular system was simulated to test the effects of the control system model. The results of these two simulations were well matched with the experimental ones. The steady state LBNP simulation was also performed. The transient changes of hemodynamic variables due to ramp increase of bias pressure of LBNP showed good agreement with the physiological experiments. Numerical solution using only the baroreflex model showed relatively a larger deviation from the experimental data. compared with the one using the control model haying both the baroreflex and the cardiopulmonary reflex systems, which shows an important role of the cardiopulmonary reflex system for the simulation of the hemodynamic behavior of the cardiovascular system .

• Journal of Korean Biological Nursing Science
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• v.11 no.1
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• pp.32-41
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• 2009

Purpose: This study was to identify the effects of aroma inhalation therapy on heart rate variability and anxiety in the context of urodynamics study. Method: The data were collected from 64 patients who were receiving urodynamics at the C University Medical Center in Seoul, 23 in the experimental group, 22 in the placebo group and 19 in the control group. In the experiment, the subjects of the experimental group inhaled a mixture of lavender and bergamot for 5 min, the subjects of the placebo group inhaled geranyl acetate oil for 5 min and the subjects of the control group relaxed for 5 min. The instruments used in this study included the state anxiety inventory and heart rate variability. Result: The score of state anxiety was no significant differences between the three groups after aroma-inhalation. Also, the sympathetic nerve activity and parasympathetic nerve activity was no significant differences between the three groups after aroma-inhalation. Autonomic nerve balance was maintained significantly in the experimental group as compared to the control groups after aroma-inhalation. Conclusion: The aroma inhalation therapy was very effective in balancing the autonomic nervous system in the patients undergoing urodynamic study.

• Journal of Acupuncture Research
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• v.27 no.6
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• pp.77-84
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• 2010

Objectives : This study was to compare the incipient grade and improvement rate between each opposite gender and part on peripheral facial nerve paralysis. Methods : We investigated 64 cases of patient with peripheral facial nerve paralysis and divided into four groups with each gender and affected part and compared their incipient grade and rate of improvement. All groups were evaluated by Yanagihara's unweighted grading system before treatment and in everyday and after treatment. Results & Conclusion : 1. There's a difference of incipient grade between each opposite affected lesion in male. But there was not significant statistics. 2. There's no difference of incipient grade between each opposite affected lesion in female. 3. There's a difference of incipient grade between each opposite gender, affected their right side. But there was not significant statistics. Left side affecting palsy is more severe than right in male, and reversed results in female. But there were not significant statistics. There's no differences between each affected lesion in female. 4. There's no differences of improvement rate between each affected lesion in female. 5. The group, affected right side had better rate of improvement than another in male. But it's not significant statistics. 6. Male group had better rate of improvement than female in both gender, affected its left lesion. But it's not significant statistics.

• The Korean Journal of Physiology
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• v.6 no.2
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• pp.49-56
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• 1972

This experiment was designed to explore specific functional relationship between the vestibular canals and the extraocular oblique muscles by observing the isometric tension responeses of the muscles to the selected vestibular canal excitation. The vestibular excitation was simulated by either stimulation of the individual canal nerve or endolymphatic fluid displacement in each canal. Each canal nerve was subjected to square wave pulses with a monopolar wire electrode placed closely to the ampullary nerve endings for electrical stimulation, and a fine stainless cannula was introduced into the each canal toward the ampulla and a minute amount $(0.5{\sim}3.5\;microliter)$ of fluid was injected in or ejected out by means of a microsyringe connected to the cannula to produce ampullopetal or ampullofugal displacement of endolymphatic fluid. The superior oblique muscle was contracted by the excitation of homolateral canals and was relaxed by contralateral canals. On the contrary, the inferior oblique was contracted by the contralateral canals and was relaxed by the homolateral canals. Summation of excitatory and inhibitory canal effects from the bilateral vestibular system was demonstrable on the tension changes of the oblique muscles. Excitation of either dual or triple canals of the unilateral vestibular system also caused summation effect on the tension response of the oblique pair; thus multiple signals from the different ampullary receptors seems to be converged into the relevant ocular motor muclei. Since the superior and inferior obliques are known to receive their motor fibers from the contralateral trochlear nuclei and intermediate nuclei of the homolateral oculomotor complex respectively, the above experimental evidences indicate that the ocular motor nuclei for oblique muscles receive excitatory signals from the contralateral vestibular canals and inhibitory signals from the homolateral canals.

• Korean Journal of Biological Psychiatry
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• v.13 no.2
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• pp.95-102
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• 2006

Object : Nerve growth factor(NGF) is a protein involved in neuronal survival and plasticity in the central nervous system, which might play an important role in stress, depression and suicide. This study was performed to determine whether there is an alteration in plasma NGF concentrations in depressed patients with suicidal attempt. Methods : The subjects were 32 depressed patients who attempted suicide and admitted in emergency room. Forty-four hospitalized non-suicidal depressive patients and the 30 normal controls were closely matched with the suicidal group in terms of age and sex. Individuals in all 3 groups were evaluated independently by a semi-structured interview for the purpose of establishing a DSM-IV criteria diagnosis. The severity of depressive symptoms was evaluated using Hamilton depression rating scale(HDRS). The severity of the suicidal behavior was evaluated by Weisman and Worden's risk-rescue rating(RRR) system and the Lethality Suicide Attempt Rating Scale(LSARS). Plasma NGF level was measured by the enzyme linked immunosorbent assay(ELISA) method. Results : There were no statistically significant differences of the plasma NGF levels among groups. LSARS and RRR did not reveal any significant correlation with ${\beta}$-NGF level in suicidal depressive patients. Conclusion : This study do not support an association between ${\beta}$-NGF and suicidal depression. However it is necessary to investigate this association through other route such as postmortem brain.

• BMB Reports
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• v.40 no.6
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• pp.1077-1082
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• 2007

Human glutamate dehydrogenase exists in hGDH1 (housekeeping isozyme) and in hGDH2 (nerve-specific isozyme), which differ markedly in their allosteric regulation. In the nervous system, GDH is enriched in astrocytes and is important for recycling glutamate, a major excitatory neurotransmitter during neurotransmission. Chloroquine has been known to be a potent inhibitor of house-keeping GDH1 in permeabilized liver and kidneycortex of rabbit. However, the effects of chloroquine on nerve-specific GDH2 have not been reported yet. In the present study, we have investigated the effects of chloroquine on hGDH2 at various conditions and showed that chloroquine could inhibit the activity of hGDH2 at dose-dependent manner. Studies of the chloroquine inhibition on enzyme activity revealed that hGDH2 was relatively less sensitive to chloroquine inhibition than house-keeping hGDH1. Incubation of hGDH2 was uncompetitive with respect of NADH and non-competitive with respect of 2-oxoglutarate. The inhibitory effect of chloroquine on hGDH2 was abolished, although in part, by the presence of ADP and L-leucine, whereas GTP did not change the sensitivity to chloroquine inhibition. Our results show a possibility that chloroquine may be used in regulating GDH activity and subsequently glutamate concentration in the central nervous system.

• Anxiety and mood
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• v.2 no.2
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• pp.101-107
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• 2006

Object : Since autonomic nerve system dysfunction was known as the mechanism of panic disorder, many researchers used heart rate variability (HRV) as means of measuring autonomic nerve function of patients with panic disorder. We aimed to examine the effect of paroxetine medication for 3 months on symptom improvement and change of heart rate variability of the patients with panic disorder. Methods : The subjects were patients with panic disorder who visited the psychiatric outpatient clinic of Samsung Medical Center in Seoul. We included panic disorder patients who were aged from 20 to 50 and in normal BMI range (from 18 to 30) to minimize the effect of age and weight on HRV data. We excluded the patients with EKG abnormalities, hypertension or other major psychiatric disorders. They took 20-40 mg paroxetine medication a day for 3 months. Alprazolam was used only during the first month to control the acute panic symptoms and was tapered off after that. We measured the acute panic inventory (API), Hamilton rating scale for anxiety and depression (HAM-A & HAM-D), Spielberger state-trait anxiety inventory (STAIS, STAIT), and Beck depression inventory (BDI) in order to assess clinical improvement of the patients. And we measured time and frequency domain HRV in the resting, standing and cognitive stress states to assess the change of HRV. All measurements were done before and after paroxetine treatment. Result : After paroxetine medication, patients showed significant improvement in all psychiatric scales. In time domain of HRV, standard deviations of all R-R intervals (SDNN) were significantly increased in all states. In frequency domain of HRV, the ratio of high frequency to total power (HF/TP) in the standing state was significantly increased. Conclusion : After 3 months paroxetine medication, panic disorder patients showed significant clinical improvement and change in HRV data such as SDNN in all states and HF/TP ratio in the standing state. This result suggests that paroxetine medication is effective for the improvement of autonomic nerve system dysfunction in panic disorder patients.