• 한국발생생물학회:학술대회논문집
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• 한국발생생물학회 2003년도 제3회 국제심포지움 및 학술대회
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• pp.100-100
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• 2003

Pluripotent embryonic stem (ES) cells differentiate spontaneously into beating cardiomyocytes via embryo-like aggregates. We describe the use of mouse embryonic stem (mES03) cells as a reproducible differentiation system for cardiomyocyte. To induce cardiomyocytic differentiation, mES03 cells were dissociated and allowed to aggregate (EB formation) at the presence of 0 75% dimethyl sulfoxide (DMSO) for 4 days and then another 4 days without DMSO (4+/4-). Thus treated EBs were plated onto gelatin-coated dish for differentiation. Spontaneously contracting colonies which appeared in approximately 4-5 days upon differentiation. Expression of cardiac-specific genes were determined by RT-PCR. Rebust expression of myosin light chain (MLC-2V), cardiac myosin heavy chain $\alpha$, cardiac muscle heavy polypeptide 7 $\beta(\beta$-MHC), cardiac transcription factor GATA4 and skeletal muscle-specific ${\alpha}_1$-subunit of the L-type calcium channel (${\alpha}_1 CaCh_{sm}$) were detected as early as 8 days after EB formation, but message of cardiac muscle-specific $\alpha$$_1$-subunit of the L-type calcium channel (${\alpha}_1$CaCh) were revealed at a low level. Strikingly, the expression of atrial natriuretic factor (ANF) was not detected. When spontaneous contracting cell masses were examined their electrophysiological features by patch-clamp technique, it showed ventricle-like action potential 17 days after the EB formation. This study indicates that mES03 cell-derived cardiomyocytes displayed biochemical and electrophysiological properties of cardiomyocytes and DMSO enhanced development of cardiomyocytes in 4+/4- method.

• Archives of Pharmacal Research
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• 제29권1호
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• pp.34-39
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• 2006

The antispasmodic and vasodilator activities of a newly synthesized piperidine derivative (1-(4'fluorophenacyl)-4-hydroxy-4-phenyl-piperidinium chloride) were studied in vitro. The test compound exhibited a dose-dependent relaxant effect on the spontaneous and $K^+$ (75 mM)-induced contractions of isolated rabbit jejunum with respective $EC_{50}$ values of 0.01 mM(0.01-0.02, 95% CI) and 0.30 mM (0.17-0.56). The $Ca^{++}$ channel blocking (CCB) activity was confirmed when the test compound (0.1-0.2 mM) shifted the $Ca^{++}$ dose-response curves to the right, similar to that produced by verapamil ($0.1-1.0{\mu}M$), a standard CCB. In the isolated rabbit aorta, the test compound showed a dose-dependent vasodilator effect on $K^+$ (75 mM)-induced contractions with an $EC_{50}$ value of 0.08 mM (0.02-0.26) while also suppressed the norepinephrine ($1{\mu}M$) control peak responses with $EC_{50}$ value of 0.08 mM (0.05-0.13, n=5). When tested in Langendorff perfused rabbit heart preparation, the test compound exhibited a negligible inhibitory effect on the rate or force of atrial and ventricular contractions when tested up to 5 mM. The results show smooth muscle-selective relaxant effect of the test compound on intestinal and vascular preparations mediated possibly via blockade of voltage and receptor-operated $Ca^{++}$ channels.

• 대한수의학회지
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• 제27권1호
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• pp.27-34
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• 1987

To verify the direct effects of the thyroid hormone ($T_3$) on the rabbit heart, $T_3$-Tyrode solution in vitro was perfused on the normal atrial muscles and enzymatically isolated ventricular myocytes of the rabbit. All the experimental procedures were conducted at $35^{\circ}C$ and the same procedures were repeated after Ca. 120 minutes from the beginning of $T_3$-Tyrode perfusion. Compared to the state between the normal Tyrode solution and $T_3$-Tyrode solution, results were observed on the same cells by electrophysiological methods (conventional intracellular recording and whole cell patch clamping) as soon as possible. The results obtained were as follows : 1. Action potential duration (APD) on the left atrial muscle was reduced under the perfusion of $T_3$-Tyrode. 2. Absolute refractory Period was shortened by $T_3$-Tryrode perfusion. (117 msec./114 msec., 90 msec./78 msec.) 3. Maximal Ca currents ($i_{Ca}$) were decreased in single: ventricular myocytes under the $T_3$-Tyrode (2.98 nA) than under the normal Tyrode (6.65 nA) 4. On I-V relation, reversal potential was shifted to lower membrane potential and membrane potential showing maximal $i_{Ca}$was lowered from +10mV to -20mV by $T_3$ effect. 5. Above results were likely to explain that tachycardia in the hyperthyroid state was caused in part by the reduced repolarization phase and the reduced refractory period due to the decrease of the Ca current.

• 대한의용생체공학회:의공학회지
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• 제43권4호
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• pp.280-289
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• 2022

In this paper, we present a QRS-complex detection algorithm to calculate an accurate heartbeat and clearly recognize irregular rhythm from ECG signals. The conventional Pan-Tompkins algorithm brings false QRS detection in the derivative when QRS and noise signals have similar instant variation. The proposed algorithm uses amplitude differences in 7 adjacent samples to detect QRS-complex which has the highest amplitude variation. The calculated amplitude is cubed to dominate QRS-complex and the moving average method is applied to diminish the noise signal's amplitude. Finally, a decision rule with a threshold value is applied to detect accurate QRS-complex. The calculated signals with Pan-Tompkins and proposed algorithms were compared by signal-to-noise ratio to evaluate the noise reduction degree. QRS-complex detection performance was confirmed by sensitivity and the positive predictive value(PPV). Normal ECG, muscle noise ECG, PVC, and atrial fibrillation signals were achieved which were measured from an ECG simulator. The signal-to-noise ratio difference between Pan-Tompkins and the proposed algorithm were 8.1, 8.5, 9.6, and 4.7, respectively. All ratio of the proposed algorithm is higher than the Pan-Tompkins values. It indicates that the proposed algorithm is more robust to noise than the Pan-Tompkins algorithm. The Pan-Tompkins algorithm and the proposed algorithm showed similar sensitivity and PPV at most waveforms. However, with a noisy atrial fibrillation signal, the PPV for QRS-complex has different values, 42% for the Pan-Tompkins algorithm and 100% for the proposed algorithm. It means that the proposed algorithm has superiority for QRS-complex detection in a noisy environment.

• Journal of Chest Surgery
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• 제40권2호
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• pp.136-139
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• 2007

양측성 슬와동맥 포착증후군은 주로 젊은 남자에게서 슬와동맥과 비복근, 섬유대, 슬와근과의 비정상적인 주행관계에 의한 혈류장애로 허혈성 파행을 유발하는 드문 말초 혈관질환이다. 58세 남자환자가 내원 1개월 전부터 시작된 좌측 하지의 허혈성 파행, 냉감, 3번 발가락 괴사로 입원하였다. 발목-상완 지수 감소 소견을 보여 대퇴동맥 혈관조영술을 시행하였고 좌측 하지 천부 대퇴동맥 원 위부 이하 부위 완전폐쇄소견 보였다. 심전도상 심방세동 보여서 슬와동맥 혈전증을 의심하고 유로키나제 혈전용해술을 시행하기로 결정하였다. 혈전용해술 후 좌측 슬와동맥 포착증후군이 진단되었고 해부학적 확진을 위하여 자기공명촬영를 시행하였다. 슬와동맥이 비복근 내측으로 주행하는 제1형으로 진단되었고, 슬와동맥류를 완전 제거하고 반대측 대복제정맥를 이용하여 대치술을 시행하였다. 경미한 우측 슬와동맥류는 수술하지 않고 관찰 중에 있으며 현재까지 합병증 없이 개통성이 유지되고 있다. 이에 심하게 이환된 하지는 수술적 치료를 시행하고, 경미하게 이환된 하지는 보존적 치료로 좋은 결과를 얻었기에 보고하는 바이다.

• 대한수의학회지
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• 제39권5호
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• pp.930-937
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• 1999

Atrial natriuretic peptide(ANP) is a hormone with potent natriuretic, diuretic and relaxing properties on vascular smooth muscle. Specific chemical modulator in response for the ANP secretion has not been found yet. Therefore, we have investigated the role of $Ca^{2+}$ responsible for the regulation of ANP induced by protein kinase C(PKC) on mechanically stretch-induced ANP secretion in the rat atria. The results obtained were as follows ; 1. ANP secretion and ANP concentration were increased to more in $Ca^{2+}$-free buffer than in the Kreb-Henseleit buffer on mechanically stretch-induced ANP secretion(p < 0.05), but extracellular fluid translocation(ECF) was not significant. Phorbol 12-myristate 13-acetate(PMA, $10^{-7}M$) induced ANP secretion and ANP concentration in $Ca^{2+}$-free buffer shown to more accentuate on mechanically stretch-induced ANP secretion than in the $Ca^{2+}$-free buffer(p < 0.05), but ECF translocation was not significant. 2. In the presence of ryanodine($3{\times}10^{-6}M$), PMA($10^{-7}M$) induced ANP secretion and ANP concentration in the Kreb-Henseleit buffer were shown to more increase on mechanically stretch-induced ANP secretion than in the ryanodine($3{\times}10^{-6}M$) with the Kreb-Henseleit buffer(p < 0.05), but ECF translocation was not significant. 3. In the presence of ryanodine($3{\times}10^{-6}M$), PMA($10^{-7}M$) induced ANP secretion and ANP concentration in the $Ca^{2+}$-free buffer was shown to more increase on mechanically stretch-induced ANP secretion than in the ryanodine($3{\times}10^{-6}M$) with the $Ca^{2+}$-free buffer on mechanically induced ANP secretion(p < 0.05), but ECF translocation was not significant. The results suggest that PKC-induced ANP secretion may not be related to the change of $Ca^{2+}$ on mechanically induced ANP secretion in the rat atria.

• 대한약리학회지
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• 제16권1호
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• pp.41-50
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• 1980

Chenodeoxycholic acid(CDCA) has been used as a gallstone dissolving agent since 1972. Recently, ursodeoxycholic acid(UDCA) has been reported to be effective in dissolving gallstones. Both bile acids increased bile flow. The increase in bile flow associated with an increase in cholesterol level in bile after CDCA or UDCA infusion was reported. In this study, using the smooth muscle strips of guinea pig and fowl, responses of the cholates were observed. In addition, the influence of adrenergic blocking agents on the response of the strips to cholates was investigated. Also the effects of cholates on cardiac function were examined by using isolated atria of rabbit and heart of anesthetized frog. The results are as follows: 1) All cholates, such as UDCA, CDCA, and CA produced a marked inhibitory effect on the motility in isolated duodenal strip of guinea pig and fowl, however, only UDCA showed the contraction in the isolated esophagus of fowl. These effects of cholates were blocked by propranolol. 2) In isolated guinea pig stomach strip and gall bladder, cholates exhibited a marked inhibitory effect on the motility and the effects due to UDCA and CA were blocked by phenoxybenzamine while CDCA was not affected. 3) The spontaneous and ouabain induced arrhythmia was partially abolished by cholates. However, concomitant administration of cholates with ouabain or epinephrine caused a marked prolongation in occurrence of atrial arrhythmia in comparison with ouabain or epinephrine alone in isolated rabbit atria. 4) In the heart of anesthetized frog, the epinephrine-induced arrhythmia was partially abolished by cholates. The combined treatment with cholates and ouabain or epinephrine produced a marked prolongation in occurrence of the arrhythmia in comparison with, ouabain or epinephrine alone. From the above results, it can be suggested that the effects of cholates on the smooth muscle of duodenum and esophagus are produced in response to adrenergic ${\beta}$-receptor and the effect or gall bladder and stomach is more likely due to the direct effect on the muscle. In addition, cholates exhibit a slight antiarrhythmic effect on heart, therefore, cholates can be classified as a nonselective antiarrhythmic drug, such as propranolol.

• 한국식품위생안전성학회지
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• 제2권2호
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• pp.57-65
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• 1987

한국에서 재배된 영지의 혈압 강하 작용을 검색한 결과, 두 종류의 영지 자실체에서 모두, 용량을 증가시킴에 따라 심박수, 수축기 혈압 및 확장기 혈압을 강하시킴을 관찰하였다. 또, 이러한 혈압을 강하시키는 유효 성분은 fraction B에 많이 포함되어 있음을 확인할 수 있었는데, 선천성 고혈압 쥐에 체중당 10mg을 정맥내 투여했을 때, 대조군과 비교하여 유의한 차이를 가지고 혈압을 강하시켰다. 혈액 관류 심장 표본에서의 영지의 작용을 관찰해 본 결과, sample J의 경우는 용량에 따라 심박수 및 심실 수축력을 증가시켰으나 sample K의 경우 용량을 증가시킴에 따라 심박수 및 심방 수축력을 오히려 감소시켰으며, 심실 수축력은 거의 변화가 없었고, 또, 관상동맥 혈류량을 용량의존적으로 증가시켰다. 심장에 대한 위의 모든 반응은 fraction A와 B에서만 나타났고, fraction C는 영향을 끼치지 못했다.

• Journal of Chest Surgery
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• 제43권4호
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• pp.413-416
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• 2010

47세 남자 환자가 교통사고로 인한 감속 손상후 흉부 통증 및 호흡곤란을 주소로 내원하였다. 청진시 우 흉골연에서 수축기 심잡음이 들렸고 심전도에서는 분당 120∼130회의 동빈맥을 보였다. 경흉부 심장 초음파에서 삼첨판막의 전엽이 동요하는 형태를 보였고 유두근의 파열과 함께 심한 판막 폐쇄 부전이 관찰되었다. 수술은 통상적인 심폐기하에서 우심방절개를 통해 접근하여, 전엽의 유두근과 후엽의 건삭이 파열되어 있는 것을 확인하였다. 전엽과 후엽에 각각 우심실내의 유두근으로 새로운 인공 건삭을 조성하였다. 또한 De-Vega 판륜 성형술을 병행하여 시행하였다. 저자들은 매우 드물게 발생한다고 알려져 있는 외상후 유두근 파열로 인한 삼첨판막의 기능부전의 수술을 경험하였기에 문헌고찰과 함께 보고하는 바이다.

• 대한약리학회지
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• 제30권2호
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• pp.181-190
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• 1994

In rat atrium the characteristics of purinergic receptors were investigated by observing the effects of some purinergic receptor agonists and antagonists on action potential and contractile force. The statistically significant effects of $ATP(10^{-6}{\sim}10^{-3}M)$ and adenosine $(10^{-6}{\sim}10^{-3}M)$ on normal action potential characteristics were a dose-dependent shortening of action potential duration $(APD_{90})$ by both agents and hyperpolarization by $ATP(10^{-4},10^{-3}M)$. $CAP(10^{-8}{\sim}10^{-4}M)$, an $A_1$ adenosine receptor agonist, shortened $(APD_{90})$ markedly in a dose-dependent manner and these effects were almost abolished by $DPCPX\;(10^{-6}\;M), an $A_1$, adenosine receptor antagonist, but not affected by $DMPX(2{\times}10^{-6}\;M)$, an $A_2$ adenosine receptor agonist. On the other hand, CGS $21680(10^{-7}{\sim}10^{-4}M)$, an $A_2$ adenosine receptor agonist, elicited a slight shortening of $(APD_{90})$ and these effects were inhibited by DPCPX but persisted in the presence of DPMX. Adenosine $(10^{-6}{\sim}10{\-4}\;M)$ decreased the basal contraction of atrial muscle in a dose-dependent manner and these effects were not inhibited by DMPX but by DPCPX. These results suggests that purinergic receptor agonists depress the cardiac activity by a short ening of action potential duration and this effect is mostly mediated by $A_1$ adenosine receptors in rat atrium.