tbuckley/cabot-search huggingface dataset:
Differential response to right and left ansae subclaviae stimulation of early afterdepolarizations and ventricular tachycardia induced by cesium in dogs.
Authors: JBen-David, D PZipes
Journal: Circulation (1988)

Early afterdepolarizations (EADs) are depolarizing potentials that occur before complete repolarization. They may be important in the acquired and possibly the idiopathic long QT syndrome and associated ventricular tachycardia (VT). The purpose of these experiments was to study in 20 open-chest dogs the effects of sympathetic stimulation on EADs and VT produced with cesium chloride (84 mg/kg i.v.) alone or combined with left (LAS), right (RAS), or bilateral (BAS) ansae subclaviae stimulation (2 Hz, 4 msec, 2 mA). We compared the EAD amplitude and area as a percentage of monophasic action potential amplitude and area, respectively, recorded simultaneously with contact electrodes from right (RV) and left ventricular (LV) endocardium and recorded the prevalence of VT induction during each intervention. Both LAS and BAS produced left ventricular EADs with larger amplitudes and areas than did RAS or cesium alone. BAS and LAS produced larger EADs recorded from the LV than from the RV. Cesium produced VT in six ...
Comparison of Treatments for Nonmetastatic Castration-Resistant Prostate Cancer: Matching-Adjusted Indirect Comparison and Network Meta-Analysis
Authors: Lin Wang, Channing Paller, Hwanhee Hong, Lori Rosman, Anthony De Felice, Otis Brawley, G Caleb Alexander
Journal: JNCI Journal of the National Cancer Institute (2021)

For nonmetastatic castration-resistant prostate cancer (nmCRPC), 3 drugs under patent protection-apalutamide, enzalutamide, and darolutamide-were approved based on randomized, placebo-controlled trials; 1 drug with generic availability, abiraterone acetate, showed efficacy in a single-arm trial and is commonly prescribed. Lacking head-to-head trials, the optimal treatment for nmCRPC is unknown, despite widely varied treatment costs. We compared the efficacy and safety of nmCRPC treatments.We searched bibliographic databases, regulatory documents, and trial registries for nmCRPC trials. We included published results and, when available, original data. We performed matching-adjusted indirect comparison and network meta-analysis and compared treatments regarding metastasis-free survival, overall survival, and serious adverse events.We analyzed 5 trials with 4360 participants. Compared with placebo, abiraterone acetate engendered the lowest hazard of metastasis and death (hazard ratio [HR] = 0.22, 95% credible interval [CrI] = 0.12-0.41), followed by apalutamide (HR = 0.28, 95% CrI = 0.23-0.34), enzalutamide (HR = 0.30, 95% CrI = 0.25-0.36), and darolutamide (HR = 0.41, 95% CrI = 0.34-0.49); darolutamide led to the lowest hazard of death (HR = 0.69, 95% CrI = 0.53-0.90), followed by enzalutamide (HR = 0.73, 95% CrI = 0.61-0.87) and apalutamide (HR = 0.75, 95% CrI = 0.59-0.95); darolutamide resulted in the lowest odds of serious adverse events (odds ratio [OR] = 1.32, 95% CrI = 1.02-1.70), followed by enzalutamide (OR =1.43, 95% CrI = 1.08-1.89), apalutamide (OR = 1.58, 95% CrI = 1.23-2.03), and abiraterone acetate (OR = 1.94, 95% CrI = 1.17-3.22).For nmCRPC, darolutamide offered optimal efficacy and safety among approved drugs, and abiraterone acetate may offer comparable metastasis-free survival benefit with cost savings from generic availability. Future research is needed to more fully examine the benefit of abiraterone acetate.
Comparison Of Approaches For Pancreatic Cyst Draining, Factors For Decision-Making
Authors: A Denisova, P Zhegalov, A Samoylenko
Journal: Endoscopy (2021)

Aims Pancreatic pseudocyst might occur as a complication of acute pancreatitis in 14.6 %. Large cysts could be symptomatic or complicated and need invasive treatment if more than 6 cm in diameter and does not resolve longer than 6 week. Percutaneous drainage, surgery or endoscopic draining procedures are possible approaches of treatment. Decision is not always obvious so the aim of our study was to analyze factors involved in tactic strategy choice.
Adverse effects of chronic cardiac denervation in conscious dogs with myocardial ischemia.
Authors: MLavallee, JAmano, S FVatner, W TManders, W CRandall, J XThomas
Journal: Circulation Research (1985)

The extent to which total chronic cardiac denervation protects the ischemic myocardium was investigated in conscious dogs. The major hemodynamic difference after coronary artery occlusion was that left ventricular end-diastolic pressure rose significantly more, P less than 0.01, in the denervated group (12 +/- 1.5 mm Hg) than in the normal group (4.4 +/- 1.4 mm Hg). Blood flow (radioactive microspheres) in the ischemic endo- and epicardium fell to similar levels at 3-5 minutes after coronary occlusion, but was significantly less (P less than 0.01) in denervated dogs at 3 hours after occlusion in the endo- (0.05 +/- 0.01) and epicardium (0.30 +/- 0.02 ml/min per g), than in the endo- (0.13 +/- 0.03) and epicardium (0.42 +/- 0.05 ml/min per g) in the normal group. A subgroup of normal dogs was also studied, with left ventricular end-diastolic pressure increased by volume loading to levels similar to those observed in the denervated group after coronary occlusion; in these dogs, blood flow was similar to tha...
Sudden sinus slowing with junctional escape: a common mode of initiation of juvenile supraventricular tachycardia.
Authors: A MLevy, B JBonazinga
Journal: Circulation (1983)

After noting bradycardia-induced supraventricular tachycardia (SVT) in two successive children with SVT, we analyzed Holter monitor recordings done on 66 children with suspected or proved SVT. Ten children had apparent reentry SVT. The most common mode of initiation (eight of 10 patients) was not premature atrial beats, but sudden sinus pause with a junctional escape beat (JEB), usually fused with the delayed sinus P wave, initiating the tachycardia. Electrophysiologic studies in five children who had this mode of initiation showed evidence of reentry in four, possibly by dual atrioventricular nodal (AVN) pathways. Since sudden sinus pause and JEB are relatively uncommon in adults, the disappearance of this phenomenon with age may be the most significant reason why children often have less tachyarrhythmia as they get older. Both propranolol and digoxin significantly increased the numbers of episodes of SVT in the three patients tested with serial Holter monitoring.
Gene transfer into coronary arteries of intact animals with a percutaneous balloon catheter.
Authors: G DChapman, C SLim, R SGammon, S CCulp, J SDesper, R PBauman, J LSwain, R SStack
Journal: Circulation Research (1992)

Genetic manipulation of the vasculature may offer insights into the pathogenesis of coronary artery disease and may lead to gene therapy for disorders such as restenosis after percutaneous coronary angioplasty. The goal of this study was to develop a percutaneous method for gene transfer into coronary arteries of intact animals. Liposomes were used to facilitate transfection in coronary arteries with a plasmid containing the cDNA encoding luciferase. This reporter was chosen since it is not expressed in mammalian cells, and it can be quantified using a sensitive assay (light production). Mongrel dogs were catheterized, and DNA was delivered to coronary arteries via a porous perfusion balloon system. Luciferase expression was measured 3-5 days after the procedure, when the dogs were killed. Luciferase activity in control arteries (n = 12) was no higher than average background activity. Eight of 12 transfected arteries exhibited gene expression, averaging 4.3 +/- 2.1 pg luciferase (p less than 0.01, transfe...
Subcellular distribution of high-affinity type IV cyclic AMP phosphodiesterase activity in rabbit ventricular myocardium: relations to the effects of cardiotonic drugs.
Authors: P AKithas, MArtman, W JThompson, S JStrada
Journal: Circulation Research (1988)

Rabbit ventricular myocardium contains distinct cytosolic and particulate cyclic AMP (cAMP) phosphodiesterase activities that exhibit characteristics ascribed to a high-affinity type IV cAMP phosphodiesterase activity found in several tissues. The particulate activity associated with sarcoplasmic reticulum vesicles has an apparent Km for cAMP of about 0.3 microM and a Vmax of 2.45 +/- 0.55 nmol/min/mg. Cyclic GMP (cGMP) inhibits hydrolysis measured at 0.25 microM cAMP with an IC50 value of 0.28 microM. In comparison, a ventricular cytosolic high-affinity cAMP phosphodiesterase activity obtained by anion exchange chromatography (Peak III) has an apparent Km of 0.93 microM and a Vmax of 17 +/- 1 nmol/min/mg. Hydrolysis of 0.25 microM cAMP by this cytosolic activity is weakly inhibited by cGMP with an IC50 value of 142 microM. Particulate enzyme activity is 60-fold more sensitive to inhibition by milrinone than is the cytosolic form (Ki = 0.18 versus 11 microM, respectively); the pyridazinone imazodan is a 1...
Vitamin D supplementation to prevent acute respiratory infections: a systematic review and meta-analysis of aggregate data from randomised controlled trials
Authors: David A Jolliffe, Carlos A Camargo, John D Sluyter, Mary Aglipay, John F Aloia, Davaasambuu Ganmaa, Peter Bergman, Heike A Bischoff-Ferrari, Arturo Borzutzky, Camilla T Damsgaard, Gal Dubnov-Raz, Susanna Esposito, Clare Gilham, Adit A Ginde, Inbal Golan-Tripto, Emma C Goodall, Cameron C Grant, Christopher J Griffiths, Anna Maria Hibbs, Wim Janssens, Anuradha Vaman Khadilkar, Ilkka Laaksi, Margaret T Lee, Mark Loeb, Jonathon L Maguire, Paweł Majak, David T Mauger, Semira Manaseki-Holland, David R Murdoch, Akio Nakashima, Rachel E Neale, Hai Pham, Christine Rake, Judy R Rees, Jenni Rosendahl, Robert Scragg, Dheeraj Shah, Yoshiki Shimizu, Steve Simpson-Yap, Geeta Trilok-Kumar, Mitsuyoshi Urashima, Adrian R Martineau
Journal: The Lancet Diabetes & Endocrinology (2021)
Failure of demand pacing with small surface area electrodes.
Authors: H CHughes, R RBrownlee, G FTyers
Journal: Circulation (1976)

As pacemaker electrode myocardial contact area is reduced, the energy required to stimulate the heart decreases; but the effect of surface area on an electrode's ability to transmit R-wave potentials has not been well documented. Endocardial and intramyocardial R-wave potentials were measured in ten dogs with seven commercially available pacemaker electrodes of different surface area. With a load impedance of 1000 ohms, there was a direct correlation between surface area and the R-wave potentials measured. The amplitude of the R-wave that resulted from conduction from the heart to the sensor via the electrode system decreased with decreasing surface area. A similar direct correlation was seen between the R-wave potentials measured and the threshold current and energy requirements. With the present trend toward utilization of small surface area electrodes to reduce pacemaker cell drain, care must be taken to optimize pacemaker circuit impedance if sensing problems are to be avoided.
Fourteen-day survival among older adults with severe infection with severe acute respiratory syndrome coronavirus 2 treated with corticosteroid: a cohort study
Authors: Laure Gallay, Viet-Thi Tran, Elodie Perrodeau, Nicolas Vignier, Matthieu Mahevas, Francesca Bisio, Emmanuel Forestier, Francois-Xavier Lescure, Laure Gallay, Viet-Thi Tran, Elodie Perrodeau, Emmanuel Forestier, Matthieu Mahevas, Francesca Bisio, Nicolas Vignier, François-Xavier Lescure, Viet-Thi Tran, Elodie Perrodeau, Thibaut Fraisse, Diane Sanderink, Bertrand Lioger, Camille Boutrou, Anne - Laure Destrem, Pascal Gicquel, Martin Martinot, Jérémie Pasquier, Jean Reuter, Helene Desmurs-Clavel, Nicolas Benech, Boris Bienvenu, Nicolas Vignier, Guillemette Frémont, François Goehringer, Guillaume Chapelet, Olivier Grossi, Didier Laureillard, Cyrille Gourjault, Alexandre Lahens, François-Xavier Lescure, Célia Azoulay, Nicolas Carlier, Gianpiero Tebano, Jérôme Pacanowski, Simone Tunesi, Nadège Lemaire, Laurent Bellec, Firouze Bani-Sadr, Marie Pichenot, Kevin Alexandre, Laurie Masse, Olivier Robineau, Camille Thorey, Sophie Deriaz, Julien Saison, Marie Gousseff, Laura Goehrs, Fanny Pommeret, Francesca Bisio
Journal: Clinical Microbiology and Infection (2021)
Incomplete lysis of thrombus in the moderate underlying atherosclerotic lesion during intracoronary infusion of streptokinase for acute myocardial infarction: quantitative angiographic observations.
Authors: B GBrown, C AGallery, R SBadger, J WKennedy, DMathey, E LBolson, H TDodge
Journal: Circulation (1986)

Thrombolytic recanalization of the obstructed coronary lumen was studied in 32 patients receiving intracoronary streptokinase for 60 to 90 min during acute myocardial infarction. The process was viewed at high arteriographic magnification and was quantified with computer-assisted measurements from repeated single-plane views. The variability of the method for this application was 0.15 to 0.18 mm on minimum diameter estimates. Structural details were seen that are not commonly appreciated at conventional magnification. The recanalized lumen appears to form along an interface between the thrombus and the vessel wall, progressively enlarging its minimum arteriographic diameter to 0.65 +/- 0.24 mm (+/- 1 SD) at the end of the short-term infusion of streptokinase reflecting a final percent stenosis of 77 +/- 10%. In nine infarct lesions found patent 5 +/- 3 weeks later, the recanalized lumen further improved an average of 0.34 mm in minimum diameter (p less than .005) and 13% stenosis (p less than .01). A thin...
Reactivity of isolated porcine coronary resistance arteries to cholinergic and adrenergic drugs and transmural pressure changes.
Authors: KNakayama, GOsol, WHalpern
Journal: Circulation Research (1988)

The reactivity of porcine intramyocardial resistance arteries (223 +/- 7 micron i.d., n = 30) was investigated with a pressurized in vitro preparation. Diameter changes in response to acetylcholine and to adrenergic drugs and dynamic changes in transmural pressure changes were investigated. Acetylcholine produced concentration-dependent constrictions, causing maximal reductions of 71 +/- 3% in lumen diameter, with EC50 values averaging 1.9 X 10(-7) M (n = 7). These responses were inhibited by atropine (10(-7) M) and therefore were mediated by muscarinic receptors. In addition, acetylcholine did not elicit relaxation in nine out of 10 vessels precontracted with U46619 (10(-7) M). Norepinephrine and epinephrine never produced constrictions (n = 6) even in the presence of propranolol (10(-6) M). Both norepinephrine and isoproterenol caused dose-dependent relaxations in acetylcholine-precontracted vessels, with IC50 values of 8.2 X 10(-7) M (n = 5) and 6.6 X 10(-8) M (n = 6), respectively. These relaxations w...
High-Altitude Pulmonary Edema
Authors: Norbert F Voelkel
Journal: New England Journal of Medicine (2002)

The spectrum of acute mountain sickness ranges from mild, nonspecific symptoms to high-altitude pulmonary edema and high-altitude cerebral edema. Most deaths from high-altitude illness occur with high-altitude pulmonary edema, the risk of which is related to the rate of ascent, individual susceptibility, and the level of exertion. Cold ambient temperature constitutes an additional risk factor. High-altitude pulmonary edema occurs worldwide, with the incidence peaking in the winter months because of ski tourism. Mountain climbers and skiers who have had an episode of high-altitude pulmonary edema are susceptible to unpredictable recurrence when they are again exposed to high altitudes.The condition . . .
Myocardial infarct quantification in the dog by single photon emission computed tomography.
Authors: J WKeyes, P FLeonard, S LBrody, D JSvetkoff, W LRogers, B RLucchesi
Journal: Circulation (1978)

Radionuclide techniques for sizing acute myocardial infarction have been hampered by the intrinsic limitations of the scintillation camera. Emission computed tomography can overcome these limitations. Single photon emission computed tomograms of the distribution of technetium-99m pyrophosphate in acute anterior and posterior infarcts were obtained in 16 dogs after death. Tomograms were also obtained in 10 dogs during life without gating. The size of the infarcts was determined by staining gross sections of the heart with nitro blue tetrazolium, dissecting out the infarcted tissue and weighing it. Infarct sizes were determined from the tomographic images and compared with the measured infarct sizes. Good images showing the location and three-dimensional extent of the infarcts were obtained in all dogs. The measured and calculated infarct sizes correlated well (r = 0.85). Comparison of the calculated sizes in the living (non-gated) and dead (physiologically gated) animals showed reasonable agreement (r = ...
Mechanism of reciprocating tachycardia initiated during sinus rhythm in concealed Wolff-Parkinson-White syndrome: report of a case.
Authors: R JSung, ACastellanos, HGelband, R JMyerburg
Journal: Circulation (1976)

Reciprocating tachycardia in a patient with a leftsided atrioventricular accessory pathway (AP) (Kent bundle, type A) capable only of ventriculo-atrial (V-A) transmission is described. The V-A AP is established as an essential link of the tachycardia circuit, as evidenced by : 1) retrograde atrial activation of the left atrium (LA) 60 msec or more before the low and high right atrium during reciprocating tachycardia and during V-A conduction; 2) the absence of refractory-dependent delay in V-A conduction time with progressively premature ventricular stimulation, characteristic of retrograde conduction through an AP; and 3) the absence of antegrade conduction through the Kent bundle during sinus rhythm, reciprocating tachycardia, pacing from either atrium, or during induced atrial flutter-fibrillation. The onset of the tachycardia was unique in that it could be initiated and perpetuated during sinus rhythm, without a triggering mechanism of an atrial or ventricular extrasystole. The interplay of the follow...
Familial atrioventricular heart block; an autosomal dominant trait.
Authors: M BWaxman, J DCatching, C HFelderhof, EDownar, M DSilver, M MAbbott
Journal: Circulation (1975)

A family of 28 individuals spanning four generations was investigated because of a finding of complete heart block in five members and the existence of a low degree of atrioventricular (A-V) heart block in a sixth member. The disorder was characterized by 1) adult onset in all, 2) complete A-V heart block in five and first degree A-V heart block in one, 3) sinus bradycardia in three, 4) atrial fibrillation in five, 5) abnormal QRS complex in five, 6) ventricular tachycardia in three, 7) left ventricular enlargement in all, and 8) mitral insufficiency in five. Proximal location of the A-V heart block was suggested by the fact that atropine caused acceleration of the ventricular rate and by the presence of a His bundle potential preceding the QRS complexes. Involvement of the distal conducting system was indicated by the widened QRS complex and a prolonged H-V interval. Pathologic examination in one case showed extensive sinus node fibrosis and interruption of the A-V node-His bundle connection. This disord...
Abstract 14245: Wall Stress Comparison in Genetic Aortopathies
Authors: Abraham J Rizkalla, Rajesh Puranik, Richmond W Jeremy
Journal: Circulation (2019)

Introduction: Familial thoracic aortic aneurysm (FTAAD), Marfan syndrome (MFS) and bicuspid aortic valve (BAV) are associated with aortic dilatation. Calculations of wall stress using thin-walled (...
Regulation of large coronary arteries by beta-adrenergic mechanisms in the conscious dog.
Authors: S FVatner, T HHintze, PMacho
Journal: Circulation Research (1982)

We examined, in conscious dogs, the effects of beta-adrenergic stimulation on measurements of left circumflex coronary arterial diameter and blood flow and on calculations of late diastolic coronary resistance (LDCR) and left circumflex coronary internal cross-sectional area (CSA). Isoproterenol (0.1 microgram/kg) initially decreased mean arterial pressure by 25 +/- 2% (mean +/- SEM), and LDCR by 62 +/- 4%, and increased heart rate by 82 +/- 10%, left ventricular (LV) dP/dt by 79 +/- 12%, and mean coronary blood flow by 85 +/- 5%, while CSA rose slightly. The peak effects on CSA (24 +/- 2%) occurred later, along with decreases in mean arterial pressure (7.4 +/- 1.0%) and LDCR (25 +/-5.3%) and increases in coronary blood flow (14 +/- 2%), LV dP/dt (12 +/- 3%), and heart rate (24 +/- 4%). Pirbuterol (1.0 microgram/kg) induced changes that were qualitatively similar to those induced by isoproterenol. Prenalterol (20 micrograms/kg), a cardioselective beta 1-adrenergic receptor agonist, did not affect mean art...
Intracellular K+ activity, intracellular Na+ activity and maximum diastolic potential of canine subendocardial Purkinje cells from one-day-old infarcts.
Authors: K PDresdner, R PKline, A LWit
Journal: Circulation Research (1987)

The basis for the reduced maximum diastolic potential of canine cardiac subendocardial Purkinje fibers surviving one day after extensive transmural infarction was investigated, using double-barrel potassium and sodium ion-sensitive microelectrodes. The maximum diastolic potential of Purkinje fibers in infarct preparations from the left ventricular apex measured during the first hour of superfusion in a tissue bath was -50.1 +/- 13.7 mV, a value markedly reduced from the value in control Purkinje fibers from noninfarcted preparations (-85.0 +/- 4.5 mV). The intracellular potassium ion activity was reduced by 50.4 mM during this time (intracellular potassium ion activity equals 61.6 +/- 16.1 mM, as compared to control intracellular potassium ion activity of 112 +/- 19.8 mM). The potassium equilibrium potential was reduced by 16.0 mV (from -97.2 +/- 4.7 mV in controls to -81.2 +/- 6.9 mV), thus accounting for about one half of the reduction in the maximum diastolic potential. After 6 hours of superfusion, th...
Left ventricular dynamic geometry in the intact and open chest dog.
Authors: K RWalley, MGrover, G LRaff, J WBenge, BHannaford, S AGlantz
Journal: Circulation Research (1982)

No approach to describing the heart's dynamic geometry has been widely adopted, probably because all require questionable assumptions of chamber shape, symmetry, or placement of the measuring devices. In other words, these approaches require assumptions about shape to reach conclusions about shape. We present an analysis that avoids such assumptions and provides an objective description of how the left ventricle deforms and rotates during the cardiac cycle. We only assume that the deformation of the left ventricular cavity is homogeneous, and explicitly validate this assumption. Our analysis yields the following new information about the contracting left ventricle: three principal directions of deformation and the relative length change alone these directions: the axis and angle of rotation, and relative volume. All these changes are referenced to the ventricle's configuration at end-diastole. We instrumented 13 dogs with tantalum screws without opening their chests. During systole, the three principal di...