• The Korean Journal of Physiology
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• v.10 no.1
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• pp.41-48
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• 1976

Tetrodotoxin (TTX) is the purified active principle responsible for tetrodon (Puffer-fish) poisoning which has long been known in the Orient. The pharmacological actions of TTX have been rather extensively investigated. Two of the most prominent effects of intravenousely administered TTX are severe hypotension and respiratory paralysis resulting from its depressant actions on tissues. This depressant actions of TTX in turn result from the selective inhibition of sodium-carrying mechanism which is essential to generation of the action potential. TTX differs from local anesthetics in that it does not affect potassium conductance. Although the mechanism of the hypotensive action of TTX remains a subject of controversy, most investigator agree that TTX-induced hypotension is caused by alteration in the blood vessels rather than the heart. Not only the study on the effects of TTX on cardiac function is meager but the results of reported works are often contradictory. The present study was undertaken to investigate the effect of TTX on the electrocardiogram of the rabbit and to compare them with well known electrocardiographical characteristics found in digitalis and quinidine intoxicated animals. The results obtained from the present study are summarized as follows. 1. No changes were found in P-R interval and QRS duration after i.v. administration of $1.0\;{\mu}g/kg\;to\;1.5\;{\mu}g/kg$ TTX to the animals. It is obvious that there were no conduction disturbance between atria and ventricles as well as in the ventricular tissue. 2. In $1.0\;{\mu}g/kg$ TTX group, S-T interval and T-P segment were not changed whereas marked changes were observed in $1.5\;{\mu}g/kg$ TTX group. 3. The first and second degree A-V blocks appeared in the $2.0\;{\mu}g/kg$ TTX group. 4. TTX differs from digitalis and quinidine in that it does not cause S-T interval depression and T-wave inversion. In contrast with digitalis, TTX caused Q-T interval prolongation.

• YAKHAK HOEJI
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• v.43 no.6
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• pp.716-728
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• 1999

Whole oil and ketonic fraction (KF) of Leptospermum scoparium have been tested for their antimicrobial activity and combination effect with several antibiotics against various bacterial strains and fungi by using microbiological assay methods. Antibacterial activities of KF against a number of test strains were 2-3 fold stronger than those of whole oil. MICs of the KF were $65~125{\;}{\mu\textrm{g}}/ml$ against seven gram positive bacterial strains, $65~250{\;}{\mu\textrm{g}}/ml$ against 19 methicillin resistance Staphylococcus aureus strains, and $65~50{\;}{\mu\textrm{g}}/ml$ against 14 quinolone resistance strains. However, KF showed little or no activity against gram negative bacteria. MICs of the KF were $16~250{\;}{\mu\textrm{g}}/ml$ against more than 50% of the anaerobic bacterial strains tested. KF showed the higher antibacterial activity than bacitracin against 10 strains of Bacteroids thetaiotaomicron, or three strains of Bacteroides ovatus, and the more active than ciprofloxacin against one strain of Bacteroides thetaiotaomicron and three strains of Bacteroids ovatus. The MICs of KF was 63 and $250{\;}{\mu\textrm{g}}/ml$ against Aspergillus niger and Candida albicans, respectively. Antibacterial activities of KF in combination with 19 antibiotics against 14 strains and with four antifungal agents against one fungal strain were determined by paper strip diffusion method. While most of combination showed additivity, KF showed synergism with bacitracin, exfadroxil, cephradin, and meropenem for 29~57% of the strains tested. However, ofloxacin, enoxacin, sparfloxacin showed antagonism with KF for 43~71% of the strains. KF alone and in combination with bacitracin, gentamycin, neomycin, itraconazole, fluconazole, terfinafine and ketoconazole against five bacterial strains or one fungus strain synergistic effect was demonstrated against 33% of strains examined with FIC index value below 0.5 by checkerboard study. Synergistic effect of KF with gentamicin against Staphylococcus epidermidis 329 (QRS) was found by time-kill study.

• Tuberculosis and Respiratory Diseases
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• v.69 no.6
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• pp.474-479
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• 2010

Torsades de pointes associated with a prolonged QT interval is a life-threatening arrhythmia, which may be induced by any of the following: drugs, electrolyte imbalances, severe bradycardia and intracranial hemorrhage. Torsades de pointes is characterized by beat-to-beat variations in the QRS complexes in any ECG leads with rates of 200~250 per minute. Fluoroquinolones are widely used and well tolerated antibacterial agents. However, prolongation of the QT interval leads rarely to Torsades de pointes as a significant adverse effect. So, it should be used with caution in high-risk patients for developing Torsades de pointes. We report one case of 67-year old man with contact burns who experienced Torsades de pointes, which probably resulted from the use of levofloxacin, and no further episode occurred after its withdrawal.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.33 no.4
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• pp.106-112
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• 2022

Objectives: We aimed to evaluate the clinical and psychological factors influencing depressive symptoms in children and adolescents with epilepsy. Methods: We administered self-reported questionnaires assessing children's depressive symptoms (Children's Depression Inventory, CDI) and anxiety (Revised Children's Manifest Anxiety Scale, RCMAS) to children and adolescents with epilepsy (n=87, age range=6-17 years). We asked their parents to complete questionnaires on epilepsy-related variables, parental stress (Questionnaire on Resources and Stress, QRS), parental anxiety (State-Trait Anxiety Inventory, STAI), family functioning (Family Adaptability and Cohesion Evaluation Scale, FACES), children's attention problems (Abbreviated Conners Parent Rating Scale Revised, CPRS), and children's behavioral problems (Korean Child Behavior Checklist, K-CBCL). Stepwise multiple regression analysis was performed to identify predictive variables affecting depressive symptoms. Results: Family adaptability (r=-0.240, p=0.026), family cohesion (r=-0.381, p<0.001), children's attention problems (r=0.290, p=0.006), children's anxiety (r=0.714, p<0.001), children's behavioral problems (r=0.371, p<0.001), parental anxiety (r=0.320, p=0.003), and parental stress (r=0.335, p=0.002) were significantly correlated with children's depressive symptoms. Children's anxiety (β=0.655, p<0.001) and parental stress (β=0.198, p=0.013) were significantly related to their depressive symptoms (adjusted R²=0.539). Conclusion: Clinicians should detect and manage children's anxiety and parental stress, which may affect depressive symptoms in children and adolescents with epilepsy.

• Journal of Biomedical Engineering Research
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• v.43 no.2
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• pp.124-130
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• 2022

In this paper, we proposed a portable electronic cardiogram and stethoscope (ECGS) that can simultaneously perform the electrocardiogram (ECG) and auscultation tests to increase the reliability of diagnosis of heart disease. To measure the ECG and heart sound (HS) at the same time, three ECG electrodes and a microphone sensor were combined into a triangular shape with a width of 90 mm and a height of 97 mm that can be held in one hand. In order to prevent skin problems when they contact the patient's skin, a capacitive coupled electrode was selected as the ECG electrode and a silicone material was used in a chest piece with the microphone sensor. For the signals measured from the electrodes and the chest piece, filters were respectively configured to pass only the signals of 0.01-100 Hz and 20-250 Hz, which are frequency bands for ECG and HS. The filtered ECG and HS analog signals were converted into digital signals and transmitted to a PC using wireless communication for monitoring them. The HS could be auscultated simultaneously using an earphone. The monitored ECG had an SNR of about 34 dB and a P-QRS-T waveform is clearly visible. In addition, the HS had an SNR of about 28 dB and both S₁ and S₂ are clearly visible. It is expected that it can aid doctors' inexperience in analyzing the ECG and HS.

• Journal of Cardiovascular Imaging
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• v.30 no.1
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• pp.62-75
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• 2022

BACKGROUND: Due to its location very close to the bundle of His, mitral annulus calcification (MAC) might be associated with the development of atrioventricular (AV) conduction disturbances. This study assessed the association between MAC and AV conduction disturbances identified by cardiac implantable electronic device (CIED) use and electrocardiographic parameters. The association between MAC and traditional cardiovascular risk factors was also assessed. METHODS: This cross-sectional study analyzed 14,771 participants, predominantly men aged 60-75 years, from the population-based Danish Cardiovascular Screening trial. Traditional cardiovascular risk factors were obtained. Using cardiac non-contrast computed tomography imaging, MAC scores were measured using the Agatston method and divided into absent versus present and score categories. CIED implantation data were obtained from the Danish Pacemaker and Implantable Cardioverter Defibrillator Register. A 12-lead electrocardiogram was available for 2,107 participants. Associations between MAC scores and AV conduction disturbances were assessed using multivariate regression analyses. RESULTS: MAC was present in 22.4% of the study subjects. Participants with pacemakers for an AV conduction disturbance had significantly higher MAC scores (odds ratio [OR], 1.11; 95% confidence interval [CI], 1.01-1.23) than participants without a CIED, whereas participants with a CIED for other reasons did not. Prolonged QRS-interval was significantly associated with the presence of MAC (OR, 1.45; 95% CI, 1.04-2.04), whereas prolonged PQ-interval was not. Female sex and most traditional cardiovascular risk factors were significantly associated with high MAC scores. CONCLUSIONS: MAC was associated with AV conduction disturbances, which could improve our understanding of the development of AV conduction disturbances.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.661-667
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• 2003

Purpose : This study was performed to find the chief clinical problems associated with the ages of adult patients of tetralogy of Fallot(TOF) who had undergone total correction. Methods : Of the 30 patients who were registered at the Grown-Up Congenital Heart Disease (GUCH) Clinic of Samsung Medical Center for TOF, a retrospective investigation was carried out on 28 patients who underwent total correction. Results : Mean age at retrospective study was 30.8(range : 16-53) years old. Age at total correction was 15.8(range : 2-49) years old. Problems after corrective surgery were assessed. They were arrhythmia, pulmonary valve regurgitation, left pulmonary artery stenosis, residual ventricular septal defect, mitral valve regurgitation, tricuspid valve regurgitation, right ventricle outflow tract obstruction, aortic valve regurgitation, infective endocarditis and protein losing enteropathy. After repair of TOF, such arrhythmias as atrial arrhythmia and AV conduction disturbances were observed in some patients. Cardiomegaly was found significantly in the subjects with arrhythmia(P<0.05), and arrhythmia was less observed in patients who underwent surgery at a young age. Eight patients required a reoperation; the main indications were residual ventricular septal defect, right ventricle outflow tract obstruction and peripheral pulmonary artery stenosis. Conclusion : The majority of the patients seemed to live normal lives after Tetralogy of Fallot repair. However, as residual anatomic and functional abnormalities exist postoperatively, continued careful follow-up is needed to detect and correct structural and functional abnormalities.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.106-116
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• 2001

Background : Pulmonary thromboembolism is relatively frequent and potentially fatal. However, it is commonly misdiagnosed. The incidence of pulmonary thromboembolism is not decreasing despite advances in diagnosis and effective prophylatic measures. Its potential for significant sequela necessitates a prompt diagnosis and treatment. Unfortunately, there are many difficulties and problems regarding accurate diagnosis. There is a low prevalence of deep vein thrombosis and pulmonary thromboembolism in Korea and only few reports on this subject are available. Method : The clinical features of 36 patients, who were diagnosed with pulmonary thromboembolism at the Korea University medical center, were reviewed. Results : 1) There was no significant difference in prevalence between men an women, and the mean age was 50.9 years in men 59.2 years in women. 2) The frequent causes of pulmonary thromboembolism were malignancies (22.2%), surgery (22.2%), and heart disease(8.2%). Specific causes were not identified in 33.3%. 3) The most common symptom was dyspnea(72.2%), and the most common sign was tachypnea(61.1%). 4) The EKG findings were normal in 28.6%, an S1Q3T3 pulmonale pattern in 25.7%, ST or QRS changes in others. 5) The chest X-ray findings indicated pulmonary infiltration in 37.5%, cardiomegaly in 15.6%, pleural effusion in 12.5%, and normal in 27.8%. The perfusion lung scan showed a high probability in 66.7%, and intermediate or low probability in 33.3%. 6) The pulmonary arterial pressure(PAP) in the high probability groups was 57.9mmHg with a higher mortality rate(35%). Conclusion : Pulmonary thromboembolism is not uncommon in Korea and its clinical features do not differ greatly from thase reported in the literature. When pulmonary thromboemblism of unknown causes are diagnosed, a search for an occult malignancy is recommended. Rapid diagnosis and treatment are achieved when thromboemblism is suspected.

• 순환기질환의공학회:학술대회논문집
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• 2005.12a
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• pp.25-26
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• 2005

동맥경화의 재발생 위치는 속도와 전단응력 등과 같은 혈류역학의 인자들의 영향을 많이 받는 혈관형태를 가진 영역이다. 이러한 결과는 관상동맥에 동맥경화의 발생빈도를 조사한 결과와 일치하고 있으며, 즉 좌전 하행지, 회선지, 및 우관동맥 등의 동맥경화성 병변 발생빈도에서 좌전하행지가 가장 많은 빈도를 나타낸다. 따라서 동맥경화의 발생 및 재형성은 혈관의 동맥경화성 위험지역의 형태적 특징, 즉, 분지부의 위치, 길이, 각도의 변화 등에 따라 달라질 수 있음을 시사한다. 동일한 관상동맥이더라도 동맥경화의 발생이 용이한 형태가 있는데, 혈관의 형태학적 특성에 따란 혈류역학적 특성이 달라지고 동맥경화가 발생할 수 있는 가능성이나 진행과정이 차이가 날 수 있음을 말한다. 특히 임계치를 넘는 고전단응력은 혈관내피세포를 파괴하거나 손상을 주며, 반대로 임계치 미만의 저전단응력은 혈류의 정체시간을 길게 하여 양쪽 모두 동맥경화성 생물학적 반응을 유발 할 수 있며, 고전단응력과 저전단응력의 빈번한 맥동성 변화작용으로 혈관이 손상될 수 있는 한계범위를 넘어서게 될 때 내피세포의 방어체계를 파괴시키거나 혈관성형술후의 신내포세포 형성과정에서 생물학적 활성반응을 촉진하게 되는 환경을 제공하게 되어 동맥경화를 촉진한다고 할 수 있다. 즉 임계치 이상의 고전단응력이 나타나는 형태와 입구경계조건이 발생되면 내피세포 손상에 따른 혈전 현상의 발생가능성이 높아지며, 임계치 미만의 저전단응력이 발생되면 동맥경화성 죽상반 재형성에 영향을 미치게 한다. 결론적으로 동맥경화의 재발생의 기전은 변형된 혈관의 형태학적인 차이와 위치에 따라 서로 다른 혈류역학적 유발할 수 있는 물리적 환경을 제공하는 데에서 출발한다고 할 수 있다.$8.0{\sim}8.3$으로 알카리 쪽으로 이동하였다. 파일롯트 규모로 본 고정화 효소 충전탑(내경 30cm, 높이 85cm)에 의한 이성화당의 생산을 시도하였던바, 고정화 효소(350 IXIU/ml-R) 1리터가 30일동안에 약 293리터의 이성화당을 생산할 수 있는 것으로 나타났다.l plane에서 선수군(選手群)이 $62.7{\pm}7.36^{\circ}$로서 비선수군(非選手群)과 별(別) 차이(差異)가 없었고, horizontalplane에서는 선수군(選手群)이 $-23.5{\pm}7.2^{\circ}$로서 비선수군(非選手群)의 $-38.8{\pm}8.2^{\circ}$에 비(比)해 유의(有意)하게 높았으며 운동후(運動後) 양군(兩群) 모두 유의(有意)하게 높았다. QRS vector 길이에서 Frontal plane에서 선수군(選手群)이 $13.86{\pm}1.44\;mm$로서 비선수군(非選手群)의 $9.62{\pm}0.97\;mm$에 비(比)해 유의(有意)하게 높았으며 운동후(運動後)에도 유의(有意)하게 높았다. Horizontal plane에서도 선수군(選手群)이 $19.82{\pm}2.10\;mm$로서 비선수군(非選手群)의 $16.90{\pm}1.39\;mm$에 비(比)해 유의(有意)하게 높았고 운동후(運動後)에도 선수군(選手群)이 유의(有意)하게 높았다. 이상(以上)을 종합(綜合)해 보면 선수군(選手群)의 R파고(波高)가 비선수군(非選手群)에 비(比)해 운동후(運動後) 계속(繼續) 유의(有意)하게 높았고, $Rv_5$

• Korean Journal of Biological Psychiatry
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• v.7 no.2
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• pp.191-197
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• 2000

Objectives : Risperidone is a new antipsychotic drug developed to overcome the therapeutic limitation of conventional antipsychotics. It responses to negative as well as positive symptoms by blocking both dopaminergic and serotonergic receptors, causing no significant side effects such as agranulocytosis and seizure. It is, however, not known whether it induces any serious cardiovascular side effects as evoked by other conventional antipsychotic drugs. The aims of this study were to evaluate the effect of risperidone on cardiovascular function, and to discuss the factors affecting the cardiovascular function. Methods : For 42 patients(22 males and 20 females) diagnosed as schizophrenia, schizophreniform disorder or schizoaffective disorder according to the DSM-IV classification, the cardiovascular fuctions such as heart rate, systolic and diastolic blood pressure, PR interval, QRS interval and QT interval were successively checked before and after 2 weeks and 4 weeks risperidone administration. Furthermore, variables such as body weight, Brief Psychiatric Rating Scale(BPRS), Clinical Global Impression(CGI), Extrapyramidal Symptom Rating Scale(ESRS), Anticholinergic Rating Scale(ARS), serum cholesterol level, serum triglyceride level, serum high-density-lipoprotein level, serum WBC, serum Hb, serum platelet level, prothrombin time and partial thromboplastin time were also analyzed before and after 2 weeks and 4 weeks risperidone administration. Results : 1) Risperidone treatment resulted in a significantly decreased heart rate and increased QT interval after 4 weeks administration(p<0.005 respectively). 2) The scores of BPRS and CGI were significantly decreased after 2 weeks and 4 weeks risperidone administration as compared with baseline(p<0.001 respectively). The scores of ESRS and ASRS were significantly increased after 2 weeks and 4 weeks risperidone administration as compared with baseline(p<0.001 respectively). 3) There were positive correlations between heart rate after 4 weeks and total dose(P<0.05). Blood pressure was significantly(p<0.05) correlated with sex(higher in male) and significantly(p<0.05) positive correlated with body weight. QT interval was significantly(p<0.05) correlated with sex(longer in female) and smoking history(shorter in smokers). Conclusions : Risperidone could induce significant change in heart rate and Q-T interval. Therefore, the cardiovascular safety for risperidone should be reconsidered according to the duration and dosage increase.