• The Korean Journal of Legal Medicine
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• v.42 no.4
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• pp.159-163
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• 2018

Progressive muscular dystrophy (PMD) is a primary muscle disease characterized by progressive muscle weakness and wasting, which is inherited by an X-linked recessive pattern and occurs mainly in males. There are several types of muscular dystrophies classified according to the distribution of predominant muscle weakness including Duchenne and Becker, Emery-Dreifuss, facioscapulohumeral, oculopharyngeal, and limb-girdle type. Clinical manifestations of PMD are clumsy, unsteady gait, pneumonia, heart failure, pulmonary edema, hydropericardium, hydrothorax, aspiration, syncopal attacks, and sudden cardiac death. The deceased was a 34-year-old man, and the onset of the first clinical symptom, gait disturbance, was in his late teens. His elder brother had the same disease and experienced brain death after a head trauma and died after mechanical ventilation was discontinued. After an autopsy, we found contracture of the joints, pseudohypertrophy of the calf, wasting and fat replacement of the thigh muscle, pericardial effusion (80 mL), fibrosis and fat replacement of the cardiac ventricular wall, pulmonary edema, and froth in the bronchus. The cause of death was heart failure and dyspnea due to muscular dystrophy. There was no sign or suspicion of foul play in his death.

• The Korean Journal of Physiology
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• v.1 no.1
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• pp.67-72
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• 1967

Present paper is attempted to introduce the phenomenon of 'after contraction' in isolated cardiac-muscle. Papillary muscles were removed from cat right ventricle and were used as a preparation. The muscle strip was Placed in tissue bath which is kept in steady temperature of around $25^{\circ}C$ and was perfuced by Tyrode solution, saturated with 95% $O_2$ and 5% $CO_2.$ under the condition of high calcium (8.2-10.0 mM/l), low sodium (72.4-70.0 mM/l) perfusion with the administration of epinephrine (1-2 mg/l) into tile tissue bath normally triggered muscle contraction was followed by oscillatory, repetitive contractions - after contraction. The phenomenon of after contraction was augumented by decrease in tissue bath temperature and by increase in number of preceding beats and in driving rate. Authors were able to maintain the phenomenon in prominent and steady state giving proper experimental conditions such as fixed bath temperature (ranged from $22^{\circ}C\;to\;27^{\circ}C$), suitable driving rate (20 per minute in average) and perfusion of high calcium, loll sodium and 1-2 mg/l of epinephrine. In some preparations, the strength of after contraction (second contraction) reached up-to 80% of normally triggered contraction and five repetitive contractions were observed as largest number of after contractions. Intracellular action potential measured in the muscle which was beating regulary showing steady after contraction revealed no oscillating after potential in most parts of the muscle but in few cases oscillating changes of after potentials were detectable. In electrogram of the muscle preparation recorded by means of contact electrode prominent, oscillating after potentials were observable when the recorder was set at highest sensitivity. It still is not clear that whether after contraction is the phenomenon which corresponds to those changes in action potential, oscillating after potential, of the muscle preparation. Possible mechanism of the phenomenon of after contraction relating with after potential changes was proposed. Detailed results obtained from further studies on after contraction and concrete discussion on the phenomenon will be reported by authors.

• The Korean Journal of Physiology and Pharmacology
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• v.26 no.5
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• pp.357-365
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• 2022

Simultaneous myofibril and mitochondrial development is crucial for the cardiac differentiation of pluripotent stem cells (PSCs). Specifically, mitochondrial energy metabolism (MEM) development in cardiomyocytes is essential for the beating function. Although previous studies have reported that MEM is correlated with cardiac differentiation, the process and timing of MEM regulation for cardiac differentiation remain poorly understood. Here, we performed transcriptome analysis of cells at specific stages of cardiac differentiation from mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs). We selected MEM genes strongly upregulated at cardiac lineage commitment and in a time-dependent manner during cardiac maturation and identified the protein-protein interaction networks. Notably, MEM proteins were found to interact closely with cardiac maturation-related proteins rather than with cardiac lineage commitment-related proteins. Furthermore, MEM proteins were found to primarily interact with cardiac muscle contractile proteins rather than with cardiac transcription factors. We identified several candidate MEM regulatory genes involved in cardiac lineage commitment (Cck, Bdnf, Fabp4, Cebpα, and Cdkn2a in mESC-derived cells, and CCK and NOS3 in hiPSC-derived cells) and cardiac maturation (Ppargc1α, Pgam2, Cox6a2, and Fabp3 in mESC-derived cells, and PGAM2 and SLC25A4 in hiPSC-derived cells). Therefore, our findings show the importance of MEM in cardiac maturation.

• Journal of The Korean Society of Inherited Metabolic disease
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• v.5 no.1
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• pp.18-22
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• 2005

Pompe disease is a genetic disorder caused by a deficiency of acid ${\alpha}$-glucosidase (GAA). This enzyme defect results in lysosomal glycogen accumulation in multiple tissues and cell types, with cardiac, skeletal, and smooth muscle cells the most seriously affected. Infantile-onset Pompe disease is uniformly lethal. Affected infants present in the first few months of life with hypotonia, generalized muscle weakness, and a hypertrophic cardiomyopathy, followed by death from cardiorespiratory failure or respiratory infection, usually by 1 year of age. Late-onset forms is characterized by a lack of severe cardiac involvement and a less severe short-term prognosis. Enzyme replacement therapy for Pompe disease is intended to address directly the underlying metabolic defect via intravenous infusions of recombinant human GAA to provide the missing enzyme. We experienced one case of Pompe disease in 3-years old boy that has improved his exercise ability and cardiac function after GAA enzyme replacement therapy.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.5
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• pp.359-363
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• 2014

MicroRNAs (miRs) are endogenous ${\approx}22$-nt non-coding RNAs that participate in the regulation of gene expression at post-transcriptional level. MiR-1 is one of the muscle-specific miRs, aberrant expression of miR-1 plays important roles in many physiological and pathological processes. In this review, we focus on the recent studies about miR-1 in cardiac diseases and cancers. The findings indicate that miR-1 may be a novel, important biomarker, and a potential therapeutic target in cardiac diseases and cancers.

• Proceedings of the KIEE Conference
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• 1988.07a
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• pp.727-730
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• 1988

In this paper, cardiac parameters and relationship between stroke volume and impedance change were explained, and an impedance cardiograph was designed and constructed, and its accuracy was verified by experiment. Useful cardiac parameters such as stroke volume and contractility of cardiac muscle were measured noninvasively. The reproducibility of the instrument was measured to be better(less than 10%) than that of clinical standard method such as thermodilution. Hence impedance cardiography was found to be better technique for monitoring stroke volume and contractility of patients for pre and post operation, and pharmacological studies.

• Journal of Chest Surgery
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• v.20 no.4
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• pp.765-772
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• 1987

Double-chambered right ventricle [DCRV] as a clinical and anatomic entity was separated from other forms of right ventricle obstruction, and frequently associated with VSD. We experienced surgical treatment of 6 cases of DCRV with VSD. Among them, PDA in a case, PFO in two cases and one case of mild infundibular PS were associated. Preoperative cardiac catheterizations and RV cineangiograms showed about 69 mmHg. of pressure gradient in average between RV inflow and outflow portion, and filling defect by anomalous muscle bundles in the sinus portion of RV. On operation, VSD and other associated anomaly were corrected after resection of anomalous muscle bundle for relief of the obstruction through the vertical RV-tomy site. Postoperative EKG showed complete RBBB, but hemodynamic problems were not developed. Postoperative cardiac catheterizations showed markedly decreased pressure gradient between two chambers, that was about 15 mmHg. in average. Postoperative course was smooth and discharged without any problems.

• BMB Reports
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• v.43 no.3
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• pp.151-157
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• 2010

$Ca^{2+}$ is a universal signalling molecule that affects a variety of cellular processes including cardiac development. The majority of intracellular $Ca^{2+}$ is stored in the endoplasmic and sarcoplasmic reticulum of muscle and non-muscle cells. Calreticulin is a well studied $Ca^{2+}$-buffering protein in the endoplasmic reticulum, and calreticulin deficiency is embryonic lethal due to impaired cardiac development. Despite calsequestrin being the most abundant $Ca^{2+}$-buffering protein in the sarcoplasmic reticulum, viability is maintained in embryos without calsequestrin and normal $Ca^{2+}$ release and contractile function is observed. The $Ca^{2+}$ homeostasis regulated by the endoplasmic and sarcoplasmic reticulum is critical for the development and proper function of the heart.

• Journal of Chest Surgery
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• v.16 no.1
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• pp.34-39
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• 1983

The syndrome of anomalous muscle bundle dividing the right ventricle into two pressure chambers has been described by many authors. The malformation should not be confused with tetralogy of Fallot itself because the obstructive hypertrophic bands are usually proximal to the right ventricular infundibulum. One case [11 years old male] of double chambered right ventricle due to aberrant muscle bundle with intact ventricular septum is presented. The pressure gradient was 68 mmHg between inflow and outflow tracts of right ventricle on cardiac catheterization. On opening the right ventricle, there noted stenosis of outflow tract by infundibular membrane, hypertrophied anomalous muscle bundle, thickened moderator band & hypertrophied anterior papillary muscle. Open heart surgery was carried out with the aid of extracorporeal support, Anomalous muscle bundle [1.0 cm x 4.0 cm] and infundibular membrane were resected safely. The hypertrophied moderator band was cut at mid-portion and anterior papillary muscle was split vertically. The postoperative course was uneventful and discharged in good condition 2 weeks later.

• Journal of the Korea Society of Computer and Information
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• v.24 no.2
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• pp.157-161
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• 2019

In this paper, the researcher investigated whether strengthening the back muscles affects the quality of chest compressions during cardiopulmonary resuscitation by university students. A total of 50 students majoring in healthcare were included from September 2018 to November. The participants performed chest compressions during cardiopulmonary resuscitation (CPR) for 2 min after back muscle strength was measured. Then, after adequate rest, the participants repeated the back muscle strength measurements and chest compressions after taping the erector spinae muscle. The paired t-test was performed to analyze changes in chest compression quality after taping. As results, taping enhanced back muscle strength and positively affected the depth of chest compressions and the compression to recoil ratio. Taping also increased confidence and lowered fatigability during chest compressions, so the participants preferred being taped while performing chest compressions. Based on these results, taping could help emergency room medical personnel specialized in CPR to enhance the quality of CPR and relieve back pain and fatigability by strengthening the back muscles.