• The Korean Journal of Physiology
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• v.16 no.1
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• pp.13-23
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• 1982

Effects of external pH and potassium concentrations on the electrical and mechanical properties were investigated on rabbit papillary muscle. Papillary muscles were perfused in horizontal chamber with Tris Tyrode solutions and action potential along with isometric tension was recorded simultaneously. Potassium concentrations were varied between 1 and 12 mM at low(6.9), normal(7.4) and high (7.9) external pH. The following results were obtained: 1) On rasing the potassium concentration from 1 to 12 mM resting membrane potentials decreased from $-88.8{\pm}2.8$ to $-66.4{\pm}1.2\;mV$ at normal pH and the amplitude of action potential decreased from $115.1{\pm}0.7$ to $97.5{\pm}2.8\;mV$. On lowering the potassium concentration, membrane hyperpolarized and at 1 mM potassium concentration resting potentials were $-107{\pm}2.2\;mV$. Duration of action potential especially $APD_{60}{\sim}APD_{90}$ increased($APD_{90}$: $214{\pm}15.8\;ms$ at 1 mM $K^+$ to $287{\pm}18.1\;ms$ at 12 mM $K^+$). 2) During acidosis membranes hyperpolarized by more than 20 mV within 1 min. and then slow recovery was observed during the following 10 min. During alkalosis membranes depolarized about 10 mV, which were maintained until washing with normal Tyrode solutions. 3) On lowering the external pH(7.9-6.5), duration of action potential increased progressively and it was most prominent at pH 6.5 and $K^+$ 1mM. 4) Magnitude of developed tension was $0.6{\pm}0.14\;g/mm^2$ at normal pH and potassium concentration (stimulus frequency : 60/min). Relative isometric tension to normal value increased along the increment of stimulus frequency($44.2{\pm}4.2%$ at 6/min to $271{\pm}86.7%$ at 180/min). Force-frequency relations were altered quantitatively during the perfusion with different external pH solutions. 5) Developed tension did not show marked variation within the range of $2{\sim}8\;mM$ potassium concentrations. Positive inotropism was observed at less than 2 mM $K^+$ and negative inotropism beyond 12 mM $K^+$ concentrations. From the above results we concluded that the effects of potassium ion concentration on electrical and mechanical properties of rabbit papillary muscle are related to the changes in surface negative charge due to acid base disturbances.

• Korean Journal of Acupuncture
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• v.26 no.2
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• pp.15-25
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• 2009

Objective: This paper aimed to understand influences on EEG conducting acupuncture stimulation, by comparing the changes in the acupoints on the body before and after normal people are treated with acupuncture at PC9 and TE3, which are referred to as Wood points(木穴), and PC5 and TE1, which are referred to as the Metal points(金穴) among the five shu points of Yin pericardium Meridian and Yang Triple Energizer Meridian. Methods: The study was performed on 30 healthy female volunteers in their 20's. EEG was measured for 5 minutes before acupuncture stimulation was conducted on PC9, TE3, PC5 and TE1. During 20 minutes of acupuncture treatment, the same items were continuously measured to find out whether there were any changes in them, and they were measured for 5 minutes after removing the acupuncture needles in order to implement a comparative analysis. Results: Comparision of EEG data before and after the treatment at PC9 shows no significant differences in all wave. Compared with the pre-acupuncture period at TE3, $\delta-\theta$ wave decreased significantly (P<0.05) during the acupuncture stimulation periods. Compared with the pre-acupuncture period at PC5, $\delta-\theta$ wave and high $\alpha$ wave increased significantly (P<0.05) during the acupuncture stimulation periods. And Mid $\beta$ wave and high $\beta$ wave decreased significantly (P<0.05) during the acupuncture periods and the post acupuncture periods. Compared with the Pre-acupuncture period at TE1, $\delta-\theta$ wave, $\theta$ wave and high $\alpha$ wave increased significantly (P<0.05) during the acupuncture stimulation periods. And Low $\beta$ wave decreased significantly (P<0.05) during the acupuncture periods. Conclusion: When acupuncture stimulation was performed on PC9 and TE3, referred to as the "Wood points", brain waves were stabled, while when acupuncture was performed on PC5 and TE1, called the "Metal points", a brain was waked. From the findings of this study, we hypothesize that the wood properties, from which growing starts in all things, are related with fast waves of EEG, and the metal properties, which stabilize and converge in all things, are related with slow waves of EEG.

• Journal of Life Science
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• v.31 no.7
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• pp.662-670
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• 2021

Interstitial cells of Cajal (ICCs) are the pacemaking cells in the gastrointestinal (GI) muscles that generate the rhythmic oscillation in membrane potentials known as slow waves. In the present study, we investigated the effects of mirtazapine, a noradrenergic and serotonergic antidepressant, on pacemaking potential in cultured ICCs from the murine small intestine. The whole-cell patch-clamp configuration was used to record pacemaker potential in cultured ICCs. Mirtazapine induced pacemaker potential depolarizations in a concentration-dependent manner in the current clamp mode. Y25130 (a 5-HT3 receptor antagonist), RS39604 (a 5-HT4 receptor antagonist), and SB269970 (a 5-HT7 receptor antagonist) had no effects on mirtazapine-induced pacemaker potential depolarizations. Also, methoctramine, a muscarinic M₂ receptor antagonist, had no effect on mirtazapine-induced pacemaker potential depolarizations, whereas 4-diphenylacetoxy-N-methyl-piperidine methiodide (4-DAMP), a muscarinic M₃ receptor antagonist, inhibited the depolarizations. When guanosine 5'-[β-thio] diphosphate (GDP-β-S; 1 mM) was in the pipette solution, mirtazapine-induced pacemaker potential depolarization was blocked. When an external Ca²⁺ free solution or thapsigargin, a Ca²⁺-ATPase inhibitor of the endoplasmic reticulum, was applied, the generation of pacemaker potentials disappeared, and under these conditions, mirtazapine induced pacemaker potential depolarizations. In addition, protein kinase C (PKC) inhibitor, calphostin C, and chelerythrine inhibited mirtazapine-induced pacemaker potential depolarizations. These results suggest that mirtazapine regulates pacemaker potentials through muscarinic M₃ receptor activation via a G protein-dependent and an external or internal Ca²⁺-independent PKC pathway in the ICCs. Therefore, mirtazapine can control GI motility through ICCs.

• Clinical and Experimental Reproductive Medicine
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• v.33 no.4
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• pp.237-243
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• 2006

Objective: The aim of this study was to evaluate the efficacy of frozen-thawed ET in poor prognosis patients such as the old age (38~44 years; OA group) and the patients who did not achieve clinical pregnancy with the first fresh ET cycle (non-pregnant patients; NP group). Methods: Laboratory and clinical data were collected from fresh and frozen-thawed ET cycles of OA and NP group. Controlled ovarian hyperstimulation (COH) and conventional insemination or ICSI, in vitro culture and ET were performed by routine procedures. Supernumerary embryos were frozen by the slow freezing method, and frozen embryos were thawed by the rapid thawing method. Embryo development, pregnancy and implantation rates were statistically analyzed by Student t-test and chi square test Results: Mean ages were similar between fresh ET ($40.0{\pm}1.8$ years, n=206) and frozen-thawed ET ($39.9{\pm}1.9$ years, n=69) cycles in OA group. However, the clinical pregnancy and implantation rate of subsequent frozen-thawed ET significantly higher than those of fresh ET cycles (29.0% and 11.2% vs. 16.5% and 7.0%, p<0.05). In NP group, there was no difference in the mean age between fresh ET ($31.2{\pm}2.3$ years, n=40) and frozen-thawed ET ($31.9{\pm}3.1$ years, n=119) in subsequent cycles. The clinical pregnancy and implantation rates were similar between the subsequent fresh ET (42.5% and 22.6%) and the frozen-thawed ET (40.3% and 18.8%). Conclusion: In old age patients, higher pregnancy rate of frozen-thawed ET compared to fresh ET cycles in this study. It may be related that better uterine environments for implantation in frozen-thawed ET cycles than that of non-physiological hormonal condition in uterus of fresh COH cycles.

• Sleep Medicine and Psychophysiology
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• v.7 no.1
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• pp.34-42
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• 2000

Objectives: Periodic limb movements in sleep(PLMS) is a moderately prevalent disorder, of which pathophysiology remains largely unknown. PLMS has been reported to be common in patients with obstructive sleep apnea syndrome(OSAS), but reports on their relationship have been inconsistent in previous studies. Inconsistency of results may be attributable to insufficient number of the study subjects. We attempted to explore the influence of OSAS on PLMS in a large number of subjects. Methods: Three hundred and twenty subjects(M : F=192:128) with PLMS, as identified by the nocturnal polysomnography, were studied. Sample mean age was 53.1(SD=15.1) years and their mean periodic limb movement index(PLMI) is 25.2/hr (SD=24.8). PLMS subjects were divided into two groups, based on the presence or absence of OSAS. Periodic limb movement indices and sleep parameters between two groups were analyzed to evaluate the effects of OSAS on PLMS. Results: Each of PLMI and PLMI with arousal(PLMAI) correlated positively with age. PLMI of men was larger than that of women (p<0.01). The presence of comorbid OSAS independently had influence on PLMI(t=-2.20, p<0.05), but not PLMAI. There were no significant differences between the two groups in their PLMI, PLMAI and sleep parameters. However, the two groups differed in PLMI-correlated sleep parameters. In PLMS subjects with comorbid OSAS, PLMI was negatively correlated with each of slow wave sleep time and REM sleep time. In subjects without comorbid OSAS, PLMI was negatively correlated with sleep efficiency. Conclusion: PLMS patients with OSAS turned out to have increased PLMI than those without OSAS We suggest that OSAS patients may have subtle autonomic arousals and these arousals could, in part, express themselves as PLM.

• Clinical and Experimental Pediatrics
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• v.51 no.3
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• pp.286-292
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• 2008

Purpose : We performed EEG and PET on children with epilepsy concomitantly in order to evaluate the effects of epileptiform and non-epileptiform discharge of EEG on glucose metabolism. Methods : Seventy three children with epilepsy who had PET and EEG simultaneously were included in our study. The subjects were classified in two ways: (1) based on the frequency of epileptiform discharge and (2) the severity of non-epileptiform discharge. We evaluated the clinical aspects of their seizures, the severity of focal slow waves during the interictal period with the frequency of spikes or sharp waves in order to compare with the PET results. Results : The subjects were divided by the frequency of epileptiform discharge, with 13 in the no/rare group, 7 in the occasional group, and 53 children in the frequent group. The concordant rates with PET in each group were 0%, 42.9%, and 67.9%, respectively, showing high correlations with the frequency of epileptiform discharge (P<0.05, r=0.491). The subjects as divided by the severity of non-epileptiform discharge were 15 in the no group, 25 in the infrequent group, 17 in the intermediate group, and 16 in the continuous group. The concurrence rates with PET for each group were 13.3%, 52.0%, 64.7%, and 68.8%, respectively, also showing a high correlation with the severity of non-epileptiform discharge (P<0.05, r= 0.365). Conclusion : Epileptiform discharge and non-epileptiform discharge in EEG showed a certain association with hypometabolism in PET. We recommend EEG to reduce false lateralization and to localize lesions in cases of high frequency and severity.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.495-500
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• 1993

Background: For the relief of the occlusion of major bronchi, laser therapy, radiation therapy or combined therapy is generally used. But the effect of radiation therapy is very slow and not consistent and laser therapy requires expensive equipments and technical expertise with occasional serious side effects. Direct ethanol injection has been widely used for the control of bleeding in gastrointestinal lesion, esophageal varices or renal cell carcinoma with good results. So we tried direct injection of ethanol into the tumor to relieve the obstruction of major bronchus in 11 patients. Method: All procedures were done under the fiberoptic bronchoscopy with continuous oxygen supplement and aliquoted 0.5-1.0 ml of absolute ethanol directly into the tumor through the endobronchial aspiration needle. The tumor was endoscopically removed with a biopsy forceps immediately after ethanol injection. The whole procedure was repeated 3-4 days interval until the lumen opens. Usually after 2-3 trials of ethanol injection, the lumen opened up. Results: The immediate effect of ethanol injection was whitening of the mucosa and prompt cessation of bleeding. The late effect was necrosis of the tumor. The final results of this procedure were improvement of symptoms and reexpnasion of the lung in all patients. $FEV_{1.0}$ and FVC were improved and $PaO_2$ was increased from $68.1{\pm}9.2$ mmHg to $83.9{\pm}8.1$ mmHg, $SaO_2$: from $94{\pm}8.5%$ to $96.6{\pm}1.1%$, and $AaDO_2$ was reduced from $26.5{\pm}8.5$ mmHg to $10.9{\pm}9.1$ mmHg. Conclusion: Direct ethanol injection into the tumor tissue is a rapid, cheap and relatively safe method of relieving the complete occlusion of major bronchus.

• Progress in Medical Physics
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• v.28 no.4
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• pp.135-143
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• 2017

Chemical Exchange Saturation Transfer (CEST) imaging is a method to detect solutes based on the chemical exchange of mobile protons with water. The solute protons exchange with three different patterns, which are fast, slow, and intermediate rates. The CEST contrast can be obtained from the exchangeable protons, which are hydroxyl protons, amine protons, and amide protons. The CEST MR imaging is useful to evaluate tumors, strokes, and other diseases. The purpose of this study is to review the mathematical model for CEST imaging and for measurement of the chemical exchange rate, and to measure the chemical exchange rate using a 3T MRI system on several amino acids. We reviewed the mathematical models for the proton exchange. Several physical models are proposed to demonstrate a two-pool, three-pool, and four-pool models. The CEST signals are also evaluated by taking account of the exchange rate, pH and the saturation efficiency. Although researchers have used most commonly in the calculation of CEST asymmetry, a quantitative analysis is also developed by using Lorentzian fitting. The chemical exchange rate was measured in the phantoms made of asparagine (Asn), glutamate (Glu), ${\gamma}-aminobutyric$ acid (GABA), glycine (Gly), and myoinositol (MI). The experiment was performed at a 3T human MRI system with three different acidity conditions (pH 5.6, 6.2, and 7.4) at a concentration of 50 mM. To identify the chemical exchange rate, the "lsqcurvefit" built-in function in MATLAB was used to fit the pseudo-first exchange rate model. The pseudo-first exchange rate of Asn and Gly was increased with decreasing acidity. In the case of GABA, the largest result was observed at pH 6.2. For Glu, the results at pH 5.6 and 6.2 did not show a significant difference, and the results at pH 7.4 were almost zero. For MI, there was no significant difference at pH 5.6 or 7.4, however, the results at pH 6.2 were smaller than at the other pH values. For the experiment at 3T, we were only able to apply 1 s as the maximum saturation duration due to the limitations of the MRI system. The measurement of the chemical exchange rate was limited in a clinical 3T MRI system because of a hardware limitation.

• Health Policy and Management
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• v.23 no.1
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• pp.19-34
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• 2013

Background: The study describes the changes resulted from imposition on tertiary hospital outpatient coinsurance rate rise policy and in tertiary or general hospital drug coverage rise policy on healthcare service utilization. Methods: Accordingly, the hypothesis about outpatient healthcare utilization after rise policy in outpatient coinsurance rate and drug coverage was established, using interrupted time-series analysis and segmented regression analysis to test the hypothesis. 5-year analysis period (2007. 3-2012. 3) from the outset year was designated, the data about most common 10 high-ranking of the main diseases targeting visiting patient from age of 6 to 64 were collected. Results: The summary on the major research is followed. First, the medical expense and duration of treatment tends to be increased in case of imposition about rise policy in outpatient coinsurance rate in the tertiary hospital under the interrupted time-series analysis. It showed temporary increase and slow down on account of influenza A even after the policy enforcement. In segmented regression analysis, duration of visit and medical expense in the tertiary hospital increased temporally right after the policy implementation and the decreased rapidly depends on period. Both rise and fall is statistically significant. The second, In case of tertiary or general hospital outpatient drug coverage rise policy, all of the tertiary hospital healthcare service utilization variables by the interrupted time-series analysis, drug coverage policy in the general hospital deeply declined according to decreasing trend before policy implementation. The third, in case of segmented regression analysis, the visit duration and medical expense statistically declined right after the policy implementation in both the tertiary and general hospital. Meanwhile, administration day was statistically meaningful only for the decrease right after the policy implementation. Otherwise, general hospital changes are not statistically meaningful. And the medicine cost was statistically, meaningfully decreased after the increase in drug coverage. Conclusion: Finally, the result demonstrated according to the analysis is only 1 hypothesis is denied, the other 2 are partially supported. Then, tertiary hospital outpatient coinsurance rate increase policy comparatively makes decrease effect on long-term healthcare utilization, and tertiary or general hospital outpatient drug coverage policy showed partially short-term effect is assured.

• The Korean Journal of Physiology and Pharmacology
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• v.12 no.4
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• pp.185-191
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• 2008

Activation of c-Jun N-terminal kinase (JNK), a member of the mitogen-activated protein kinase family, is an important cellular response that modulates the outcome of the cells which are exposed to the tumor necrosis factor (TNF) or the genotoxic stress including DNA damaging agents. Although it is known that JNK is activated in response to genotoxic stress, neither the pathways to transduce signals to activate JNK nor the primary sensors of the cells that trigger the stress response have been identified. Here, we report that the receptor interacting protein (RIP), a key adaptor protein of TNF signaling, was required to activate JNK in the cells treated with certain DNA damaging agents such as adriamycin (Adr) and 1-${\beta}$-D-arabinofuranosylcytosine (Ara-C) that cause slow and sustained activation, but it was not required when treated with N-methyl-N-nitro-N-nitrosoguanidine (MNNG) and short wavelength UV, which causes quick and transient activation. Our findings revealed that this sustained JNK activation was not mediated by the TNF (tumor necrosis factor) receptor signaling, but it required a functional ATM (ataxia telangiectasia) activity. In addition, JNK inhibitor SP-600125 significantly blocked the Adr-induced cell death, but it did not affect the cell death induced by MNNG. These findings suggest that the sustained activation of JNK mediated by RIP plays an important role in the DNA damage-induced cell death, and that the duration of JNK activation relays a different stress response to determine the cell fate.