AIM To determine the optimum resting tension(ORT) for in vitro human pulmonary artery(PA) ring preparations.METHODS Pulmonary arteries were dissected from disease free sections of the resected lung in the operating th...AIM To determine the optimum resting tension(ORT) for in vitro human pulmonary artery(PA) ring preparations.METHODS Pulmonary arteries were dissected from disease free sections of the resected lung in the operating theatre and tissue samples were directly sent to the laboratory in Krebs-Henseleit solution(Krebs).The pulmonary arteries were then cut into 2 mm long rings.PA rings were mounted in 25 m L organ baths or 8 m L myograph chambers containing Krebs compound(37 ℃,bubbled with 21% O_2:5% CO_2) to measure changes in isometric tension.The resting tension was set at 1-gram force(gf) with vessels being left static to equilibrate for duration of one hour.Baseline contractile reactions to 40 mmol/L KCl were obtained from a resting tension of 1 gf.Contractile reactions to 40 mmol/L KCl were then obtained from stepwise increases in resting tension(1.2,1.4,1.6,1.8 and 2.0 gf).RESULTS Twenty PA rings of internal diameter between 2-4 mmwere prepared from 4 patients.In human PA rings incrementing the tension during rest stance by 0.6 gf,up to 1.6 gf significantly augmented the 40 mmol/L KCl stimulated tension.Further enhancement of active tension by 0.4 gf,up to 2.0 gf mitigate the 40 mmol/L KCl stimulated reaction.Both Myograph and the organ bath demonstrated identical conclusions,supporting that the radial optimal resting tension for human PA ring was 1.61 g.CONCLUSION The radial optimal resting tension in our experiment is 1.61 gf(15.78 m N) for human PA rings.展开更多
Background and Aim of Study: The phosphodiesterase inhibitors (Sildenafil and Milrinone), Nitric Oxide donor Sodium Nitroprusside (SNP) and prostacyclin analogs are commonly used pulmonary vasodilators to treat pulmon...Background and Aim of Study: The phosphodiesterase inhibitors (Sildenafil and Milrinone), Nitric Oxide donor Sodium Nitroprusside (SNP) and prostacyclin analogs are commonly used pulmonary vasodilators to treat pulmonary hypertension. In the past few years, we have used human pulmonary artery rings in vitro to evaluate pulmonary vascular resistance. The main objective of the current study is to document the pharmacological impact of clinically used prostacyclin analogs on the human pulmonary system in parallel with phosphodiesterase inhibitors and SNP. Methods: The study used human pulmonary artery rings of internal diameter of 2 - 4 mm and length of 2 mm. These were extracted from patients with lung resections. These rings were then mounted on a multiwire myograph, and changes in isometric tension were noted. Then, concentration response curves were constructed to Sildenafil (Sd), Milrinone (Mil), Sodium Nitroprusside (SNP), Epoprostenol (Ep), Iloprost (Ip) and Treprostinil (Tp). Results: 52 pulmonary artery rings were used in these experiments. Sildenafil, Milrinone, SNP, Epoprostenol, Iloprost and Treprostinil caused a concentration-dependent vasodilation in small human pulmonary arteries (pEC50: 5.97 ± 0.22, 5.99 ± 0.12, 7.64 ± 0.08, 7.53 ± 0.14, 8.84 ± 0.15 and 9.48 ± 0.13 respectively, n = 8 to 12). The efficacy for the same was in the order: Tp = Ip > Ep > Mil > SNP > Sd. The potency varied in the order: Tp > Ip > SNP > Ep > Mil > Sd. Conclusion: This research showed the efficacy as well as the potency of SNP and phosphodiesterase inhibitors and prostacyclin analogs on the human pulmonary vasculature. Treprostinil and Iloprost exhibited maximum relaxation. However, Sildenafil and SNP showed lesser impact. These effects need to be considered for clinical studies for enhanced patient outcomes.展开更多
The Vieussens’ arterial ring (VAR) is a rare coronary anomaly that may be associated with a pulmonary fistula, and has been linked to ischemia, myocardial infarction, heart failure, arrhythmias, and sudden death. We ...The Vieussens’ arterial ring (VAR) is a rare coronary anomaly that may be associated with a pulmonary fistula, and has been linked to ischemia, myocardial infarction, heart failure, arrhythmias, and sudden death. We present the case of a 54-year-old man who was admitted to the emergency room with angina and dyspnea on moderate exertion, in the context of atrial fibrillation and decompensated heart failure with left ventricular systolic dysfunction. In the study of its etiology, coronary computed tomography angiography (CCTA) identified an anomalous conal artery outflow (type C) as part of the VAR and a fistula to the pulmonary artery trunk (variant 1b), with an arterial flow linking the conal artery and the middle third of the left anterior descending artery (LAD), which then fistulized to the pulmonary artery trunk. The hemodynamic and clinical repercussions presented with signs of ischemia in the LAD territory and acute heart failure. In this case, CCTA identified the coronary anomaly and its trajectory with great precision through volume rendering reconstruction, as well as the dynamics of coronary flow in the presence of the pulmonary fistula. This anatomical variant is rarely described, and CCTA is of great utility in the therapeutic decision for fistula closure.展开更多
文摘AIM To determine the optimum resting tension(ORT) for in vitro human pulmonary artery(PA) ring preparations.METHODS Pulmonary arteries were dissected from disease free sections of the resected lung in the operating theatre and tissue samples were directly sent to the laboratory in Krebs-Henseleit solution(Krebs).The pulmonary arteries were then cut into 2 mm long rings.PA rings were mounted in 25 m L organ baths or 8 m L myograph chambers containing Krebs compound(37 ℃,bubbled with 21% O_2:5% CO_2) to measure changes in isometric tension.The resting tension was set at 1-gram force(gf) with vessels being left static to equilibrate for duration of one hour.Baseline contractile reactions to 40 mmol/L KCl were obtained from a resting tension of 1 gf.Contractile reactions to 40 mmol/L KCl were then obtained from stepwise increases in resting tension(1.2,1.4,1.6,1.8 and 2.0 gf).RESULTS Twenty PA rings of internal diameter between 2-4 mmwere prepared from 4 patients.In human PA rings incrementing the tension during rest stance by 0.6 gf,up to 1.6 gf significantly augmented the 40 mmol/L KCl stimulated tension.Further enhancement of active tension by 0.4 gf,up to 2.0 gf mitigate the 40 mmol/L KCl stimulated reaction.Both Myograph and the organ bath demonstrated identical conclusions,supporting that the radial optimal resting tension for human PA ring was 1.61 g.CONCLUSION The radial optimal resting tension in our experiment is 1.61 gf(15.78 m N) for human PA rings.
文摘Background and Aim of Study: The phosphodiesterase inhibitors (Sildenafil and Milrinone), Nitric Oxide donor Sodium Nitroprusside (SNP) and prostacyclin analogs are commonly used pulmonary vasodilators to treat pulmonary hypertension. In the past few years, we have used human pulmonary artery rings in vitro to evaluate pulmonary vascular resistance. The main objective of the current study is to document the pharmacological impact of clinically used prostacyclin analogs on the human pulmonary system in parallel with phosphodiesterase inhibitors and SNP. Methods: The study used human pulmonary artery rings of internal diameter of 2 - 4 mm and length of 2 mm. These were extracted from patients with lung resections. These rings were then mounted on a multiwire myograph, and changes in isometric tension were noted. Then, concentration response curves were constructed to Sildenafil (Sd), Milrinone (Mil), Sodium Nitroprusside (SNP), Epoprostenol (Ep), Iloprost (Ip) and Treprostinil (Tp). Results: 52 pulmonary artery rings were used in these experiments. Sildenafil, Milrinone, SNP, Epoprostenol, Iloprost and Treprostinil caused a concentration-dependent vasodilation in small human pulmonary arteries (pEC50: 5.97 ± 0.22, 5.99 ± 0.12, 7.64 ± 0.08, 7.53 ± 0.14, 8.84 ± 0.15 and 9.48 ± 0.13 respectively, n = 8 to 12). The efficacy for the same was in the order: Tp = Ip > Ep > Mil > SNP > Sd. The potency varied in the order: Tp > Ip > SNP > Ep > Mil > Sd. Conclusion: This research showed the efficacy as well as the potency of SNP and phosphodiesterase inhibitors and prostacyclin analogs on the human pulmonary vasculature. Treprostinil and Iloprost exhibited maximum relaxation. However, Sildenafil and SNP showed lesser impact. These effects need to be considered for clinical studies for enhanced patient outcomes.
文摘The Vieussens’ arterial ring (VAR) is a rare coronary anomaly that may be associated with a pulmonary fistula, and has been linked to ischemia, myocardial infarction, heart failure, arrhythmias, and sudden death. We present the case of a 54-year-old man who was admitted to the emergency room with angina and dyspnea on moderate exertion, in the context of atrial fibrillation and decompensated heart failure with left ventricular systolic dysfunction. In the study of its etiology, coronary computed tomography angiography (CCTA) identified an anomalous conal artery outflow (type C) as part of the VAR and a fistula to the pulmonary artery trunk (variant 1b), with an arterial flow linking the conal artery and the middle third of the left anterior descending artery (LAD), which then fistulized to the pulmonary artery trunk. The hemodynamic and clinical repercussions presented with signs of ischemia in the LAD territory and acute heart failure. In this case, CCTA identified the coronary anomaly and its trajectory with great precision through volume rendering reconstruction, as well as the dynamics of coronary flow in the presence of the pulmonary fistula. This anatomical variant is rarely described, and CCTA is of great utility in the therapeutic decision for fistula closure.
