• Asian-Australasian Journal of Animal Sciences
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• v.10 no.5
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• pp.528-533
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• 1997

Twenty four female Sprague-Dawley rats weighing about 190 g were used to examine changes in muscle cAMP concentrations and steady-state levels of skeletal muscle ${\alpha}$-actin mRNA during chronic administration of cimaterol, a ${\beta}$-adrenergic agonist. Cimaterol was mixed in a powdered rat diet at 10 mg/kg diet. At 3 and 21 days after the start of treatment, skeletal muscle and heart samples were collected for the measurement of cAMP concentrations and skeletal muscle ${\alpha}$-actin mRNA levels. Cimaterol increased (p < 0.01) body weight gain gradually during the first seven days of the trial period, but not thereafter. Most skeletal muscle weights and the ratio of muscle weight to body weight were increased (p < 0.05) by cimaterol treatment both at 3 and 21 days. Heart weight was also increased (p < 0.05) by cimaterol treatment at 3 and 21 days, but the ratio of heart weight to body weight was increased (p < 0.05) only at 3 day. Cimaterol decreased (p < 0.05) cAMP concentration of gastrocnemius muscle at both 3 and 21 days after treatment. However, cimaterol tended (p = 0.07) to increase cAMP concentration at 3 days in the heart. Cimaterol tended (p = 0.08) to increase the steady-state level of ${\alpha}$-actin mRNA by 60% in gastrocnemius muscle at 3 days but had no effect at 21 days. The results indicate that the pattern of hypertrophic response to chronic dietary administration of cimaterol is different between cardiac and skeletal muscle. In skeletal muscles it appears that the hypertrophy induced by cimaterol is partly due to stimulated myofibrillar protein synthesis at a pre-translational level.

• Herbal Formula Science
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• v.28 no.3
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• pp.271-280
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• 2020

Hypertension has been approved to cause disharmony between the heart and kidney such as cardiac hypertrophy and kidney dysfunction. In traditional oriental medicine Paeo-tang (PET) has been shown to have effects on blood circulation improvement. However, the beneficial effect of PET on hypertension remains unknown. In this study, we investigated that PET attenuates blood pressure and improves cardiovascular and renal function in NG-nitro-L-arginine methylester (L-NAME) rat model. Hypertensive rat models were induced by the administration of L-NAME (40 mg/kg/day) and then PET (50 or 100 mg/kg/day) or Olmetec was treated for 2 weeks. PET treatment significantly suppressed the systolic blood pressure and decreased intima-media thickness in the thoracic aorta. PET ameliorated endothelium-dependent and independent vascular relaxation in the L-NAME-induced vascular dysfunction. PET ameliorated the functional decline in the kidney such as albumin and blood urea nitrogen in plasma. These results demonstrated that PET possesses protective effects against L-NAME-induced hypertension.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.4
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• pp.447-456
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• 2018

Angiotensin-(1-9) [Ang-(1-9)], generated from Ang I by Ang II converting enzyme 2, has been reported to have protective effects on cardiac and vascular remodeling. However, there is no report about the effect of Ang-(1-9) on pulmonary hypertension. The aim of the present study is to investigate whether Ang-(1-9) improves pulmonary vascular remodeling in monocrotaline (MCT)-induced pulmonary hypertensive rats. Sprague-Dawley rats received Ang-(1-9) ($576{\mu}g/kg/day$) or saline via osmotic mini-pumps for 3 weeks. Three days after implantation of osmotic mini-pumps, 50 mg/kg MCT or vehicle were subcutaneously injected. MCT caused increases in right ventricular weight and systolic pressure, which were reduced by co-administration of Ang-(1-9). Ang-(1-9) also attenuated endothelial damage and medial hypertrophy of pulmonary arterioles as well as pulmonary fibrosis induced by MCT. The protective effects of Ang-(1-9) against pulmonary hypertension were inhibited by Ang type 2 receptor ($AT_2R$) blocker, but not by Mas receptor blocker. Additionally, the levels of LDH and inflammatory cytokines, such as $TNF-{\alpha}$, MCP-1, $IL-1{\beta}$, and IL-6, in plasma were lower in Ang-(1-9) co-treated MCT group than in vehicle-treated MCT group. Changes in expressions of apoptosis-related proteins such as Bax, Bcl2, Caspase-3 and -9 in the lung tissue of MCT rats were attenuated by the treatment with Ang-(1-9). These results indicate that Ang-(1-9) improves MCT-induced pulmonary hypertension by decreasing apoptosis and inflammatory reaction via $AT_2R$.

• Journal of Veterinary Clinics
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• v.39 no.5
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• pp.240-245
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• 2022

A 15-year-old, neutered male, Shih-Tzu, was presented at the Chonnam National Veterinary Medical Teaching Hospital for evaluation of acute onset of persistent coughing, exercise intolerance, and abnormal heart sound. On thoracic auscultation, a split-second heart sound and a wheezing sound were detected on both sides of the chest walls. On physical examination, the dog's body condition score (BCS) was 7/9, and had stenotic nares. Thoracic radiographs revealed right-sided enlargement of the cardiac silhouette (vertebral heart score (VHS) 11.2; reference interval = 8.9-10.1), mild main pulmonary artery (MPA) bulging, mild interstitial infiltration, and hepatomegaly. The electrocardiogram showed right axis deviation, suggesting right ventricular hypertrophy. The echocardiographic study showed moderate pulmonary hypertension and moderate tricuspid regurgitation. There were no findings of a tracheobronchial disease, pulmonary thromboembolism, congenital shunt, left heart disease, or parasitic disease. Based on clinical signs and diagnostic findings, the dog was diagnosed with pulmonary hypertension secondary to brachycephalic syndrome. To rectify respiratory exacerbating factors, the dog was recommended weight control by restricting dietary intake and managing concurrent Cushing's syndrome. Treatments included sildenafil, pimobendan, furosemide, and ramipril. After five months of taking medications and weight control, the severity of pulmonary hypertension improved from moderate to mild. The clinical signs of the patient, including coughing and exercise intolerance, improved a lot. For 5 months of follow-up, the patient has not reported further recurrence of respiratory distress.

• Journal of Chest Surgery
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• v.43 no.6
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• pp.627-634
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• 2010

Background: The durability of the tissue valve is important in choice between a mechanical valve and a tissue valve in cardiac surgery. We studied the mid-term results of tissue valve in the aortic position. Material and Method: The subjects were 380 patients who had undergone aortic prosthesis replacement between May 1990 and March 2009. We retrospectively analyzed hospital and outpatient records: the mean age was $69{\pm}9$ years; the male to female ratio was 227 : 162; and the mean follow-up duration was $46.7{\pm}40.8$ months (range 0~196 months). Result: 389 surgical cases in total had been taken with 380 patients. Early death occurred in 15 patients (3.9%). Overall survival rate at 1, 5 and 10 years were 92.3%, 78.1% and 54.2% respectively. Freedom from reoperation at 1, 5 and 10 years were 98.4%, 97.1% and 91.7% respectively. Freedom from structural valvular deterioration at 1, 5 and 10 years were 96.1%, 92.3% and 88.0% respectively. In the multivariate analysis of preoperative risk factors, young age (p<0.001) was significant risk factor for reoperation. High peak velocity in the postoperative period (p=0.034) and young age (p=0.029) were significant risk factors for structural valvular deterioration. Old age (p=0.001), long bypass time (p=0.035), concomitant coronary artery bypass graft surgery (p=0.003) and preoperative low left ventricular ejection fraction (p=0.003) were significant factors for early mortality. Preoperative estimated glomerular filtration rate (< 60 mL/min) (p=0.025) and persistent left ventricular hypertrophy (p=0.032) were the risk factors for late mortality. Conclusion: This study showed that the freedom from reoperation and the freedom from structural valvular deterioration in aortic tissue valve replacement were acceptable. It will be necessary to conduct further studies with long-term follow-up and more patients.

• Korean Journal of Poultry Science
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• v.33 no.2
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• pp.159-164
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• 2006

To investigate the effects of salt contents in diet and water on the growth of broiler chicks, 288 heads of Hubbards strain chicks, were fed with com-soybean meal diets containing 0, 0.25, 0.5, 0.75 1.0, 2.0, 3.0, or 4.0% salt from 1d to l4d posthatching. And 180 chicks were also supplemented with salt to their water at 0, 0.1, 0.2, 0.5 or 1.0%. Feed intake and weight gain tended to decrease as the salt levels in diets increased and those were the lowest in 4% group as 481 g and 168 g, however, mortality was the highest in 4% group as 75.0%. As for the salt levels in water, feed intake and weight gain were low as 427 g and 162 g in 1% group, while mortality was 77.8%. Salt poisoning chicks were shown with thirsty, appetite deficiency, rising impossibility, sleepiness, or convulsions, and in autopsy, were shown with ascites, hydropericardium, cardiac hypertrophy, hemorrhage of eyelid, hemorrhage of trachea, hemorrhage of intestine, etc. Conclusively, salt content above 4% in diet or 1% in water could reduce the performance in broiler chicks.

• The Korean Journal of Physiology and Pharmacology
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• v.20 no.1
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

• Korean Circulation Journal
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• v.53 no.7
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• pp.425-451
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• 2023

Most patients with heart failure (HF) have multiple comorbidities, which impact their quality of life, aggravate HF, and increase mortality. Cardiovascular comorbidities include systemic and pulmonary hypertension, ischemic and valvular heart diseases, and atrial fibrillation. Non-cardiovascular comorbidities include diabetes mellitus (DM), chronic kidney and pulmonary diseases, iron deficiency and anemia, and sleep apnea. In patients with HF with hypertension and left ventricular hypertrophy, renin-angiotensin system inhibitors combined with calcium channel blockers and/or diuretics is an effective treatment regimen. Measurement of pulmonary vascular resistance via right heart catheterization is recommended for patients with HF considered suitable for implantation of mechanical circulatory support devices or as heart transplantation candidates. Coronary angiography remains the gold standard for the diagnosis and reperfusion in patients with HF and angina pectoris refractory to antianginal medications. In patients with HF and atrial fibrillation, longterm anticoagulants are recommended according to the CHA₂DS₂-VASc scores. Valvular heart diseases should be treated medically and/or surgically. In patients with HF and DM, metformin is relatively safer; thiazolidinediones cause fluid retention and should be avoided in patients with HF and dyspnea. In renal insufficiency, both volume status and cardiac performance are important for therapy guidance. In patients with HF and pulmonary disease, beta-blockers are underused, which may be related to increased mortality. In patients with HF and anemia, iron supplementation can help improve symptoms. In obstructive sleep apnea, continuous positive airway pressure therapy helps avoid severe nocturnal hypoxia. Appropriate management of comorbidities is important for improving clinical outcomes in patients with HF.

• Journal of Chest Surgery
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• v.40 no.6 s.275
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• pp.407-413
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• 2007

Background: The brain natriuretic peptide (BNP) level has been reported in some studies to be associated with the occurrence of atrial fbrillation (AF). The aim of this study is to evaluate the potential usefulness of the BNP level as a predictor of the occurrence of postoperative (postop) AF and to assess the relationship of the BNP level with the onset of AF and the restoration of sinus rhythm. Material and Method: From January 1, 2005 to February 28, 2006, 82 patients without a history of atrial arrhythmia that had undergone cardiac surgery were enrolled in the study. Blood samples for plasma BNP were drawn daily for all these patients from the preoperative (preop) day to the 7th postop day. The patient records were reviewed and postop EKGs were checked daily for AF until the time of discharge. Result: Patients were divided into two groups based on development of postop AF. Postoperative AF developed in 26 patients (31.7%). There was no significant statistical difference in age, sex distribution, preop left ventricle ejection fraction, hypertension, left ventricular hypertrophy, or the use of beta blockers between the non-postop AF and postop AF group. More patients in the AF group had undergone valve surgery (39.3% versus 76.9%, p=0.002). The preop left atrium size was significantly larger in the AF patients ($43.8{\pm}10.3 mm$ versus $49.8{\pm}11.5 mm$, p=0.029). The preop plasma BNP levels were higher in the postop AF patients ($144.1{\pm}20.8 pg/mL$ versus $267.5{\pm}68 pg/mL$, p=0.034). In the postop AF group, the plasma BNP level was the highest on the 3rd postop day. Postop AF developed in most patients by the 3rd postop day; restored sinus rhythm developed by the 7th postop day. Conclusion: Elevated plasma BNP levels may lead to the occurrence of postop AF in patients undergoing cardiac surgery. Patients who have a high risk of postop AF should be considered for aggressive prophylactic antiarrhythmic therapy.

• Journal of Chest Surgery
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• v.36 no.9
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• pp.651-658
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• 2003

Since the first implanted in September 1997, the use of On-X prosthetic heart valve has been increasing around in the world. This study was designed to assess the feasibility, safety, and the postoperative hemodynamics with this new valve in clinical setting. Material and Method: The current study was carried out on 52 patients undergoing aortic valve replacement with this prosthesis between April 1999 to August 2002 at Chonnam National University Hospital to evaluate the surgical results. 52％ of the patients were male and the average age at implant was 50$\pm$13 years. The study followed the guidelines of the AATS/STS. Preoperatively, 32(61.5％) patients were in NYHA functional class III or IV and 2 patients had previous aortic valve surgery. Concomitant cardiac surgery was performed in 71.1％. The implanted valve sizes were 19 mm in 13 patients, 21 mm in 26, 23 mm in 10 and 25 mm in 3, respectively. Mean follow-up was 16.6$\pm$10.5 months (1∼39 months). Echocardiographic assessment was performed pre- and immediate postoperatively, as well as 3, 6, 12 months after surgery, evaluating pressure loss and regression of left ventricular hypertrophy. Result: Mean cardiopulmonary bypass time was 191$\pm$94.7 minutes with an aortic cross-clamp time of 142$\pm$51.7 minutes. There was no early and late mortality, Freedom from adverse events at 1 year in the study were as follows: thromboembolism, 95.6$\pm$6％; bleeding events, 90.2$\pm$4％; paravalvular leakage 92.3$\pm$4％; and overall valve-related morbidity at 1 year was 76.6$\pm$3％. There were no cases of valve thrombosis, prosthetic valve endocarditis and structural or non-structural failure. Left ventricular function at 12 months after surgery (EF=62.7$\pm$9.8％) revealed a statistically significant improvement compared to preoperative investigation (EF=55.8$\pm$15.9％, p=0.006). Left ventricular mass index was 247.3$\pm$122.3 g/$m^2$ on preoperative echocardiographic study, but regressed to 155.5$\pm$58.2 g/$m^2$ at postoperative 1 year (p=0.002). Over the follow-up period a further decrease of peak transvalvular gradients was observed in all patients: 62.5$\pm$38.0 mmHg on preoperative assessment, 18.2$\pm$6.8 mmHg at immediate postoperative period (p < 0.0001), 7.6$\pm$5.09 mmHg (p<0.0001) at 6 month, 18.0$\pm$10.8 mmHg (p<0.0001) at 1 year. Conclusion: The On-X prosthetic heart valve performs satisfactorily in the first 1 year period. Clinical outcome by examining NYHA functional classification revealed especially good results. Effective regression of left ventricular hypertrophy and statistically significant decrease of transvalvular gradient were observed over the first year, but longer-term follow-up of this patient group is needed to establish the expected rates for late valve-related events as well as the long-term clinical efficacy of this valve.