tbuckley/cabot-search huggingface dataset:
Temporal heterogeneity of myocardial blood flow in anesthetized dogs.
Authors: H LFalsetti, R JCarroll, M LMarcus
Journal: Circulation (1975)

Temporal variation in perfusion to small segments of the myocardium was studied in 19 opened-chest dogs. In six control dogs, three or four differently labeled 7-10 mu microspheres were injected simultaneously into the left atrium to assess the variability in measured myocardial perfusion due to the microsphere technique. In 13 other dogs, microspheres were injected four times at 5 minute intervals while various hemodynamics parameters (mean aortic pressure, peak systolic pressure, heart rate, left ventricular end-diastolic pressure, and Vmax) were stable (less than 10% variation in any one parameter). The left ventricles were divided into 96 segments, the mean weight+/- SD of each segment was 0.95+/-0.17 grams. The flow to each segment was expressed as a percent of the mean flow of the three or four measured flows to that segment, and the difference between the largest and the smallest percent of each segment was taken as a measure of the variability of flow to that segment. The average variability of se...
Inotropic response to hypothermia and the temperature-dependence of ryanodine action in isolated rabbit and rat ventricular muscle: implications for excitation-contraction coupling.
Authors: M JShattock, D MBers
Journal: Circulation Research (1987)

We have used the sarcoplasmic reticulum (SR) inhibitor ryanodine to assess the contribution of the SR to the increase in twitch tension seen on cooling the mammalian myocardium. To select a suitable concentration of ryanodine, i.e., one that will exert a maximal effect at all temperatures studied, concentration-response curves for ryanodine action were constructed at 37 degrees, 29 degrees, and 23 degrees C in ventricular muscle from rabbit and rat. Using a concentration of ryanodine (1 microM) that exerted a maximal effect at all temperatures studied, the ability of ryanodine to inhibit SR function at 37 degrees, 29 degrees, and 23 degrees C was then confirmed by using rapid cooling contractures (RCCs) to provide an indirect assessment of the SR calcium content. To estimate the rest decay of the SR calcium content in the absence and presence of ryanodine (1 microM), RCCs were initiated after a range of rest intervals (0.3-300 seconds) in rabbit muscles maintained at 37 degrees, 29 degrees, or 23 degrees ...
Challenges for Measuring Cost-effectiveness of Immunotherapy in Unresectable Hepatocellular Carcinoma
Authors: Nikita Sandeep Wagle, Jennifer C. Spencer
Journal: JAMA Network Open (2021)

Xin Zhang, MD; Jingjing Wang, MD; Juanjuan Shi, MD; Xiaoli Jia, MD, PhD; Shuangsuo Dang, MD, PhD; Wenjun Wang, MD
TCTAP A-036 A Non-randomized, Clinical Registry of the DynamX Novolimus Eluting Coronary Bioadaptor System in the Treatment of Patients with De Novo Native Coronary Artery Lesions - “DynamX Hong Kong Registry”
Authors: Bryan Ping-Yen Yan, Li Wah Tam, Sunny C.F. Tsang, Wai Kin Chi
Journal: Journal of the American College of Cardiology (2021)
Uridine diphosphate–glucose/P2Y14R axis is a nonchemokine pathway that selectively promotes eosinophil accumulation
Authors: Paul S. Foster, Hock L. Tay, Simon P. Hogan
Journal: Journal of Clinical Investigation (2021)

Allergic asthma is a chronic inflammatory airway disease characterized by dysregulated type 2 immune responses, including degranulating airway eosinophils that induce tissue damage and airway hyperresponsiveness (AHR). The type 2 cytokines interleukin 5 (IL-5) and IL-13 and the eosinophil-specific chemokine CCL11/CCL24/CCL26 axis recruit, activate, and regulate eosinophils in the airways. In this issue of the JCI, Karcz et al. identified a mechanism involving the nucleotide sugar UDP-glucose (UDP-G) and the purinergic receptor P2Y14R in amplifying eosinophil accumulation in the lung. During type 2 inflammation, UDP-G activates P2Y14R on eosinophils, inducing the cells to move and migrate into the lung. Pharmacologically or genetically inhibiting P2Y14R on eosinophils attenuated eosinophil infiltration and AHR. Future experiments, including identifying additional type 2 factors regulating P2Y14R expression on lung eosinophils, are necessary to ascertain the impact of targeting P2Y14R as an alternative or adjunctive therapy to current type 2 biologics for the treatment of asthma.
Bilateral Biliary Drainage for Malignant Hilar Obstruction with EUS-Guided Hepaticogastrostomy and Hepaticoduodenostomy
Authors: KDC Pham, Engjom HM
Journal: Endoscopy (2021)

In a 76-year-old woman with ovarian carcinoma, a large metastatic hilar lesion causedcomplete obstruction of the left and right intrahepatic biliary ducts. She had severe icterus and pruritus, her prior daily function was ECOG level 2. We performed EUS-guided hepaticogastrostomy to drain the left liver lobe. Attempt to bridge the right with the left hepatic ducts through the lesion failed. The right lobe was drained by EUS-guided hepaticoduodenostomy. Five months later, the cancer was stable with tamoxifen and bilirubin normal. This case demonstrates that combined hepaticogastrostomy and hepaticoduodenostomy can achieve complete biliary drainage for malignant hilar obstruction.
Voltage- and use-dependent modulation of cardiac calcium channels by the dihydropyridine (+)-202-791.
Authors: T JKamp, M CSanguinetti, R JMiller
Journal: Circulation Research (1989)

The modulation of L-type voltage sensitive calcium channels in isolated guinea pig ventricular myocytes by the dihydropyridine (+)-202-791 was examined with the whole-cell voltage-clamp technique with 1.8 mM Ba or Ca as the charge carrier. Striking voltage- and use-dependent effects of the dihydropyridine calcium channel agonist (+)-202-791 were revealed. From a holding potential of -60 mV, depolarizing test pulses in the presence of (+)-202-791 demonstrated a concentration-dependent (EC50, 177 nM) increase in the measured peak inward barium current compared to control. In contrast, more depolarized holding potentials (greater than or equal to -30 mV) (+)-202-791 caused a biphasic effect on the peak inward current resulting in a transient enhancement followed by a steady-state block. A saturable, concentration-dependent hyperpolarizing shift in the voltage dependence of current inactivation was observed in the presence of (+)-202-791 with an EC50 of 10.2 nM. The voltage dependence of current activation ...
Nicotine exacerbates postischemic contractile dysfunction of 'stunned' myocardium in the canine model. Possible role of free radicals.
Authors: KPrzyklenk
Journal: Circulation (1994)

BACKGROUNDThere is no doubt that high doses of nicotine have deleterious effects on cardiovascular function. However, the effects of lower and more clinically relevant doses of nicotine have received little attention, and the consequences of nicotine in the setting of ischemia/reperfusion are virtually unknown. The first objective of this study was to determine whether nicotine, given either before or after ischemia and at a dose mimicking that absorbed by humans during inhalation of one cigarette, exacerbated contractile dysfunction of canine myocardium  by brief transient ischemia. The second aim was to provide preliminary insight into the mechanism of action of nicotine on the stunned myocardium.METHODS AND RESULTSAnesthetized open chest dogs underwent 15 minutes of left anterior descending coronary artery (LAD) occlusion and 3 hours of reperfusion. In protocol 1, each dog was randomized to receive nicotine at 30 minutes before LAD occlusion (80 micrograms/kg dissolved in 15 mL of saline, give...
The cardioprotective effects of ischemic 'preconditioning' are not mediated by adenosine receptors in rat hearts.
Authors: YLi, R AKloner
Journal: Circulation (1993)

BACKGROUNDAdenosine receptor activation has been proposed to explain the cardioprotective effect of ischemic preconditioning in rabbit hearts. We tested this hypothesis in a rat model by assessing whether administration of an adenosine antagonist could block the protective effect of preconditioning and whether adenosine is able to reduce infarct size in rat hearts when given before sustained coronary occlusion.METHODS AND RESULTSWe assessed the effects of the adenosine antagonist 8-(p-sulfophenyl)theophylline (SPT) and adenosine on myocardial infarct size and the incidence of ventricular arrhythmias in five groups of rats: control (nonpreconditioned)+vehicle, control+SPT, preconditioned+vehicle, preconditioned+SPT, and control (nonpreconditioned)+adenosine. All rats underwent 90 minutes of coronary artery occlusion followed by 4 hours of reperfusion while preconditioned rats underwent three 3-minute episodes of ischemia, each separated by 5 minutes of reperfusion before sustained occlusion. The area at ri...
Prevention of ischemia during percutaneous transluminal coronary angioplasty by transcatheter infusion of oxygenated Fluosol DA 20
Authors: MCleman, C CJaffee, DWohlgelernter
Journal: Circulation (1986)

Catheter balloon inflation performed during percutaneous transluminal coronary angioplasty (PTCA) results in temporary interruption of coronary blood flow and subsequent myocardial ischemia. This produces transient but profound regional left ventricular dysfunction. In an effort to mitigate this inflation-related dysfunction, oxygenated Fluosol DA 20%, a perfluorochemical oxygen transport fluid, was infused distal to the balloon through the central lumen of the dilating catheter during balloon inflation. Regional wall motion during PTCA was assessed by simultaneous continuous two-dimensional echocardiography and was quantified by computer analysis. During control inflations accompanied by no intracoronary infusion or by transcatheter infusion of Ringer's lactate solution or nonoxygenated Fluosol DA 20%, there was profound regional left ventricular dysfunction with a greater than 90% decrease in regional contraction. In contrast, regional contraction during transcatheter infusion of oxygenated Fluosol DA 2...
Influence of sex on intracellular calcium homoeostasis in patients with atrial fibrillation
Authors: Adela Herraiz-Martínez, Carmen Tarifa, Verónica Jiménez-Sábado, Anna Llach, Hector Godoy-Marín, Hildegard Colino-Lage, Carme Nolla-Colomer, Sergi Casabella-Ramon, Paloma Izquierdo-Castro, Iván Benítez, Raul Benítez, Elena Roselló-Díez, Enrique Rodríguez-Font, Xavier Viñolas, Francisco Ciruela, Juan Cinca, Leif Hove-Madsen
Journal: Cardiovascular Research (2021)

Abstract Aims Atrial fibrillation (AF) has been associated with intracellular calcium disturbances in human atrial myocytes, but little is known about the potential influence of sex and we here aimed to address this issue. Methods and results Alterations in calcium regulatory mechanisms were assessed in human atrial myocytes from patients without AF or with long-standing persistent or permanent AF. Patch-clamp measurements revealed that L-type calcium current (ICa) density was significantly smaller in males with than without AF (−1.15 ± 0.37 vs. −2.06 ± 0.29 pA/pF) but not in females with AF (−1.88 ± 0.40 vs. −2.21 ± 0.0.30 pA/pF). In contrast, transient inward currents (ITi) were more frequent in females with than without AF (1.92 ± 0.36 vs. 1.10 ± 0.19 events/min) but not in males with AF. Moreover, confocal calcium imaging showed that females with AF had more calcium spark sites than those without AF (9.8 ± 1.8 vs. 2.2 ± 1.9 sites/µm2) and sparks were wider (3.0 ± 0.3 vs. 2.2 ± 0.3 µm) and lasted longer (79 ± 6 vs. 55 ± 8 ms), favouring their fusion into calcium waves that triggers ITIs and afterdepolarizations. This was linked to higher ryanodine receptor phosphorylation at s2808 in women with AF, and inhibition of adenosine A2A or beta-adrenergic receptors that modulate s2808 phosphorylation was able to reduce the higher incidence of ITI in women with AF. Conclusion Perturbations of the calcium homoeostasis in AF is sex-dependent, concurring with increased spontaneous SR calcium release-induced electrical activity in women but not in men, and with diminished ICa density in men only.
Effect of amiodarone on the expression of myosin isoforms and cellular growth of cardiac muscle cells in culture.
Authors: A CNag, M LLee, DShepard
Journal: Circulation Research (1990)

The effect of amiodarone on the expression of myosin isoforms and the growth of neonatal rat cardiac muscle cells in culture was studied by native gel electrophoresis, assays of DNA and protein synthesis, and electron microscopy. Cardiac myocytes exposed to amiodarone in the absence of triiodothyronine (T3) showed predominant V1. When cardiac myocytes were exposed to amiodarone in the presence of T3, they expressed prevalent isomyosin V3, or both V3 and V1 equally. Supraphysiological concentration of T3 counteracted the effect of amiodarone on myocytes, showing the expression of predominant isomyosin V1. Amiodarone has inhibitory effects on DNA synthesis and differentiation of cardiac myocytes. Myocytes treated with amiodarone showed maximum labeling index with 11% labeled cells after day 1. Subsequently, the labeling indexes declined and on the third day ceased, as opposed to the control culture, which attained a peak in labeling index with 60% labeled myocytes on the third day. The labeling indexes decl...
Transposition of the great arteries. Results of treatment with early palliation and late intracardiac repair.
Authors: H PGutgesell, D GMcNamara
Journal: Circulation (1975)

A longitudinal study was made of 62 patients with dextro-transposition of the great arteries. The patients were managed with balloon atrial septostomy (BAS), palliative surgery if any operation was needed in the first year of life, and Mustard intra-atrial baffle repair after one year of age. Of the 47 patients with intact ventricular septum (IVS) treated in this manner, 41 (87 percent) were living at three months of age, 36 (77 percent) at one year, and 31 (66 percent) at two years of age. Survival rates were lower at each age for patients with associated ventricular septal defect (VSD). In relation to therapeutic interventions in the 62 patients, there were six medical deaths within one week of BAS, three deaths during palliative operations, and eight deaths associated with 31 Mustard procedures. Three patients with IVS and five with VSD developed pulmonary vascular obstructive disease, and two patients suffered strokes. In view of the relatively low mortality rate after the neonatal period and our good...
The effect of porous infusion balloon-delivered angiopeptin on myointimal hyperplasia after balloon injury in the rabbit.
Authors: M KHong, TBhatti, B JMatthews, K SStark, S SCathapermal, M LFoegh, P WRamwell, K MKent
Journal: Circulation (1993)

BACKGROUNDAngiopeptin, a synthetic somatostatin analogue, reduces myointimal hyperplasia after experimental balloon angioplasty when given subcutaneously. The feasibility and efficacy of a single dose of angiopeptin delivered locally via the Wolinsky porous balloon on myointimal hyperplasia were studied.METHODS AND RESULTSThree rabbits received 125I-angiopeptin in the mid abdominal aorta via the Wolinsky balloon at 5 atm for 1 minute after balloon injury. Thirty minutes later, autoradiography demonstrated radioactivity in the media and the adventitia. Forty rabbits were divided equally into one control group receiving saline and three angiopeptin groups receiving 1, 10, or 100 micrograms/mL of angiopeptin delivered locally at 5 atm for 1 minute via the Wolinsky balloon into the mid abdominal aorta after balloon injury of the entire abdominal aorta. On day 21, the abdominal aortas were fixed in situ and harvested. There was no statistical difference in the amount of myointimal hyperplasia in the locally tr...
Development of the coronary arteries in the embryonic human heart.
Authors: G MHutchins, AKessler-Hanna, G WMoore
Journal: Circulation (1988)

It is not known why the coronary arteries almost always originate only from the right and left aortic sinuses of Valsalva, since the structure and conditions appear to be the same for all six sinuses of the embryonic great arteries. We sought a possible mechanical explanation for the phenomenon by studying the development of the coronary vasculature in 351 staged, serially sectioned human embryos of Carnegie stages 9 through 23 from the Carnegie Embryological Collection. A plexus of blind epicardial capillaries appears on the heart in Carnegie stage 14 or 15 and acquires a coronary sinus connection in stage 15, 16, or 17. The connection of the proximal coronary arteries to the aorta does not appear until stage 18. We found no histologic features of the cardiac nerves or any other component of the tissues to account for the consistent origin of coronary arteries from the right and left aortic sinuses of Valsalva. However, serial section reconstructions showed that the two sinuses where coronary arteries de...
Effect of sublingual nitroglycerin on regional flow in patients with and without coronary disease.
Authors: JMehta, C JPepine
Journal: Circulation (1978)

We evaluated the effects of sublingual nitroglycerin on indices of regional coronary flow and coronary resistance (CR) in 12 selected patients with coronary artery disease (CAD) and eight with normal coronary arteries (NCA), using continuous thermodilution. Resting total left ventricular flow, reflected by coronary sinus flow (CSF), and anterior regional flow, reflected by great cardiac vein flow (GCVF), in NCA and CAD patient groups, were similar. However, in a subgroup of six patients, with CAD limited to the anterior descending artery, GCVF was lower and anterior regional CR (CRANT) higher than the NCA subjects. Nitroglycerin reduced the systolic pressure-heart rate product similarly in both patient groups. CSF and GCVF in NCA subjects declined 15% and 17%, respectively, as total CR (CRT) and CRANT increased. In the CAD subgroup, consisting of patients with CAD limited to the anterior descending, GCVF increased 48% as CRANT declined 50%, and CSF was unchanged. In the other CAD subgroup of patients with...
Prophylactic Clipping For The Prevention Of Delayed Bleeding After Non-Pedunculated Colorectal Polyp Resection: An Individual Patient Data Meta-Analysis
Authors: A Turan, H Pohl, M Matsumoto, B Lee, M Aizawa, F Desideri, E Albéniz, G Raju, D Luba, M Barret, S Gurudu, F Ramirez, W-R Lin, F Atsma, D Rex, B Lim, K Kwok, K Togashi, R Coriat, S Umar, Chen C-W, J Terhaar sive Droste, R Schrauwen, G Kemper, P Siersema, E van Geenen
Journal: Endoscopy (2021)

Aims Non-pedunculated colorectal polyps are usually endoscopically removed to prevent neoplastic progression. Delayed bleeding is the most common adverse event. Clipping of the resection defect has been suggested to reduce delayed bleedings. The aim of this study was to determine if prophylactic clipping reduces delayed bleedings and to analyze the contribution of polyp characteristics, extent of defect closure and routine antithrombotic use.
Inhibition of bipolar demand pacemaker by diaphragmatic myopotentials.
Authors: S SBarold, L SOng, M DFalkoff, R AHeinle
Journal: Circulation (1977)

This report describes inhibition of a normally functioning bipolar demand pulse generator by diaphragmatic myopotentials. Transient pacemaker suppression occurred repeatedly with deep respiration, straining, the Valsalva maneuver, coughing, sneezing and laughing. When the magnet was applied, none of these maneuvers inhibited the pacemaker. Extensive investigations ruled out an intermittent electrode problem such as a wire fracture or insulation break. Sensing of diaphragmatic myopotentials should be considered in the differential diagnosis of unexplained pacemaker pauses.
Digestion of cardiac and skeletal muscle junctional sarcoplasmic reticulum vesicles with calpain II. Effects on the Ca2+ release channel.
Authors: D PRardon, D CCefali, R DMitchell, S MSeiler, D RHathaway, L RJones
Journal: Circulation Research (1990)

The Ca2+ release channel and ryanodine receptor are activities copurifying with the 400,000-450,000 Da high molecular weight protein of cardiac and skeletal junctional sarcoplasmic reticulum. Calpain II, an endogenous cytosolic protease, was used to selectively degrade the high molecular weight protein in cardiac and skeletal muscle sarcoplasmic reticulum vesicles, and its effects on the activity of the Ca2+ release channel and [3H]ryanodine binding sites were analyzed. Degradation of the high molecular weight protein was associated with appearance of 315,000 and 150,000 Da proteolytic fragments and with a change in the ultrastructure of the feet, extravesicular projections that protrude from the junctional sarcoplasmic reticulum membrane. The maximal number of [3H]ryanodine binding sites and the affinities of the sites for ryanodine were not remarkably affected by calpain II. Ca2+ release channels recorded from nondegraded cardiac and skeletal membrane vesicle preparations had slope conductances of 85 ...
"Reperfusion injury" by oxygen-derived free radicals? Effect of superoxide dismutase plus catalase, given at the time of reperfusion, on myocardial infarct size, contractile function, coronary microvasculature, and regional myocardial blood flow.
Authors: KPrzyklenk, R AKloner
Journal: Circulation Research (1989)

Do oxygen-derived free radicals, generated at the time of reperfusion, lethally injure viable, previously ischemic myocardium, damage vascular endothelium, and impair recovery of postischemic contractile function? To address these issues, 23 anesthetized open-chest dogs underwent 2 hours of left anterior descending coronary artery occlusion followed by 4 hours of reperfusion. Immediately prior to reflow, each dog was randomized to receive either the free radical scavenging agents superoxide dismutase (SOD) + catalase, or saline alone. SOD + catalase had no significant beneficial effect on infarct size measured by triphenyltetrazolium staining: area of necrosis averaged 38.5 +/- 6.1% vs. 46.3 +/- 6.2% of the area at risk in treated compared with control animals respectively (p = NS). Furthermore, infusion of SOD + catalase did not alter contractile function of the viable subepicardium: mean segment shortening (measured using sonomicrometry) at 4 hours postreperfusion was -23 +/- 5% of baseline, preocclusio...
Baroreceptor control of atrioventricular conduction in man.
Authors: GMancia, OBonazzi, LPozzoni, AFerrari, MGardumi, LGregorini, RPerondi
Journal: Circulation Research (1979)

Although human baroreflexes are known to exert a powerful physiological control on heart rate, little information exists on the physiological control they exert on the atrioventricular conduction system. In 11 normotensive subjects with normal atrioventricular conduction, we altered baroreceptor activity by injection of pressor and depressor drugs (phenylephrine and trinitroglycerin) and recorded mean arterial pressure (MAP, catheter measurements), R-R interval, and pre-His and post-His intervals (A-H and H-V, His bundle recording). With the subjects in sinus rhythm, increasing MAP by 21+/- 1 mm Hg caused a marked lengthening (250 +/- 28 msec), and decreasing MAP by 17 +/- 2 mm Hg a marked shortening (142 +/- 16 msec) of the R-R interval. There was little change in the A-H interval and no change at all in the H-V interval. However, when the R-R interval was kept constant in these subjects by atrial pacing, a similar increase and decrease in MAP caused, respectively, a marked lengthening (49 +/- 6 msec) an...