tbuckley/cabot-search huggingface dataset:
Conduction disturbances caused by high current density electric fields.
Authors: SYabe, W MSmith, J PDaubert, P DWolf, D LRollins, R EIdeker
Journal: Circulation Research (1990)

During internal defibrillation, potential gradients greater than 100 V/cm occur near defibrillation electrodes. Such strong fields may cause deleterious effects, including arrhythmias. This study determined 1) the effects of such strong fields on the propagation of activation and 2) whether these effects were different for monophasic and biphasic shocks. Voltages and potential gradients during the shock, as well as activation sequences before and after the shock, were mapped from 117 epicardial electrodes placed over a 3 x 3-cm area on the right ventricle in six dogs. Pacing at a cycle length of 350 msec was given from a long narrow electrode on the right side of the mapped area to generate parallel activation isochrones. A monophasic shock, 10 msec in duration, or a biphasic shock with both phases 5 msec in duration was delivered 300 msec after the last paced stimulus via a mesh electrode on the left side of the mapped area as the cathode, with the anode on the right atrium. Shocks of 70-850 V were given...
Sympathetic and nonsympathetic neuropeptide Y-containing nerves in the rat myocardium and coronary arteries.
Authors: L ACorr, J AAberdeen, PMilner, JLincoln, GBurnstock
Journal: Circulation Research (1990)

We have examined the neuropeptide Y-containing intrinsic nerves of the heart in young (6-week-old) and adult (4-month-old) rats to determine whether they project to the coronary arteries or are capable of doing so if the neuropeptide Y-containing extrinsic nerves are removed. Chronic treatment of neonates with guanethidine was used to permanently destroy the sympathetic nerves. In the young treated animals, 33-54% of the neuropeptide Y remained in the heart despite a 90-99% reduction in norepinephrine; these proportions did not change in the animals that were allowed to develop to adulthood. The level of neuropeptide Y in the right atrium of young animals was unexpectedly high (252 +/- 28.7 pmol/g) compared with adults (75.4 +/- 18.8 pmol/g). The coronary arteries in the control rats received a moderately dense supply of neuropeptide Y-containing nerves; after guanethidine, all neuropeptide Y-containing nerves innervating the large coronary arteries disappeared, but some were still seen in association wit...
Force-pCa relation and troponin T isoforms of rabbit myocardium.
Authors: RNassar, N NMalouf, M BKelly, A EOakeley, P AAnderson
Journal: Circulation Research (1991)

We have previously reported the existence of at least four troponin T isoforms in rabbit ventricular muscle and described the changes in their distribution with development. In this report we test whether the proportions of the troponin T isoforms are related to the sensitivity of the myofilaments to calcium. We measured the force-pCa relations in 12 detergent-skinned ventricular strands of cardiac muscle from newborn (2-5-day-old) rabbits. We determined from each strand the amount of each troponin T isoform relative to the total amount of troponin T by using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and densitometric scans of Western blots probed with a cardiac-specific troponin T monoclonal antibody, MAb 13-11. To assess the presence of different relative amounts of cardiac and slow skeletal troponin I among the strands, we determined the amount of cardiac troponin I relative to tropomyosin. We determined the Hill coefficient and the pCa for half-maximal force, pCa50, for each strand. pC...
A solid angle analysis of the epicardial ischemic TQ-ST deflection in the pig. A theoretical and experimental study.
Authors: J FRicheson, TAkiyama, ESchenk
Journal: Circulation Research (1978)

The solid angle theory has long been applied to the interpretation of the ECG; however, quantitative evaluation of its applicability has been minimal. We applied solid angle analysis to the interpretation of the TQ-ST deflection during acute ischemia. Five anesthetized pigs were studied 1--3 hours after coronary occlusion. Multiple unipolar tracings were recorded from precisely determined positions on the epicardium overlying the ischemic and normal zones. The geometry of the hearts and ischemic zones was preserved, the margins of ischemia being defined as the outer border of Thioflavin S nonfluorescence. Wax replicas of the hearts with ischemic zones removed were constructed. Solid angles subtended at electrode positions on the replicas were calculated. A linear relationship (r = 0.84 - 0.97, P less than 0.001) was shown to exist between the observed TQ-ST deflection and the calculated solid angle. A small but patterned deviation from exact fit of the TQ-ST deflection with the calculated solid angle led ...
Angiotensin II induces hypertrophy, not hyperplasia, of cultured rat aortic smooth muscle cells.
Authors: A AGeisterfer, M JPeach, G KOwens
Journal: Circulation Research (1988)

We have explored the hypothesis that contractile agonists are important regulators of smooth muscle cell growth by examining the effects of one potent contractile agonist, angiotensin II (AII), on both cell proliferation and cellular hypertrophy. AII neither stimulated proliferation of cells made quiescent in a defined serum-free media nor augmented cell proliferation induced by serum or platelet-derived growth factor. However, AII did induce cellular hypertrophy of postconfluent quiescent cultures following 4 days of treatment, increasing smooth muscle cell protein content by 20% as compared with vehicle-treated controls. AII-induced hypertrophy was maximal at 1 microM, had an ED50 of 5 nM, and was blocked by the specific AII receptor antagonist Sar1,Ile8 AII. The cellular hypertrophy was due to an increase in protein synthesis, which was elevated within 6-9 hours following AII treatment, while no changes in protein degradation were apparent. AII was even more effective in inducing hypertrophy of subconf...
Pirmenol, a new antiarrhythmic agent: initial study of efficacy, safety and pharmacokinetics.
Authors: S CHammill, D GShand, P ARoutledge, M CHindman, J TBaker, E LPritchett
Journal: Circulation (1982)

Pirmenol (CI-845), a new antiarrhythmic drug, was studied for the first time in humans to establish a minimum effective i.v. dose in 10 patients with chronic, stable premature ventricular complexes (PVCs) and to evaluate toxicity and pharmacokinetics. Infusions of 70-150 mg were associated with a 90% or greater reduction in PVCs nine of the 12 times they were administered to six patients. Peak plasma concentrations were 1.0-3.8 micrograms/ml at the end of these infusions. At the same time, small but significant increases in diastolic blood pressure (4 mm Hg) and QTc interval (0.01 second) were seen, but both values were within the normal range. Pirmenol was associated with no change in heart rate, systolic blood pressure, PR interval or QRS duration, renal, hepatic or hematologic function, or symptoms. Blood, plasma and free drug concentrations declined biexponentially after cessation of a 150-mg infusion (n = 4), with a terminal half-life of 7-9.4 hours. The therapeutic response, lack of toxicity, and re...
Hepcidin levels can distinguish anemia of chronic disease from iron deficiency anemia in a cross-sectional study of patients with hidradenitis suppurativa
Authors: Mondana H. Ghias, Andrew D. Johnston, Kayla M. Babbush, Allison J. Kutner, H. Dean Hosgood, Michelle A. Lowes, Morayma Reyes Gil, Steven R. Cohen
Journal: Journal of the American Academy of Dermatology (2021)
Potentiation of the cardiovascular effects of nitroglycerin by N-acetylcysteine.
Authors: J DHorowitz, E MAntman, B HLorell, W HBarry, T WSmith
Journal: Circulation (1983)

The biochemical basis of the mechanism of vasodilatation by nitroglycerin (NTG) has not been previously investigated in man. However, evidence from in vitro studies suggests that NTG induces activation of guanylate cyclase via a series of enzymatic reactions that are modulated by the availability of sulfhydryl groups. Cysteine appears to be particularly effective in potentiating guanylate cyclase activation by NTG. To determine whether hemodynamic responsiveness to NTG in man might be modulated by sulfhydryl availability, concentration-response curves for effects of intravenously infused NTG on mean arterial pressure (MAP) and mean pulmonary capillary wedge pressure (PCW) were obtained in 10 patients undergoing cardiac catheterization for investigation of chest pain. NTG infusion was repeated 10 min after the intravenous infusion of 100 mg/kg of the cysteine source N-acetylcysteine (NAC). NAC induced no significant hemodynamic effect, but after NAC infusion there was a significant reduction both in the NT...
Characterizing the Mechanism of NE and P3 Cross-Presentation in B Cell-Acute Lymphoblastic Leukemia
Authors: Selena Carmona, Celine Kerros, Alexander Perakis, Anne Philip, Pariya Sukhumalchandra, Anna Sergeeva, Lisa St. John, Mao Zhang, Na Qiao, Elizabeth Mittendorf, Gheath Alatrash, Jeffrey J. Molldrem
Journal: Blood (2017)
Positive chronotropic responses induced by alpha 1-adrenergic stimulation of normal and "ischemic" Purkinje fibers have different receptor-effector coupling mechanisms.
Authors: E PAnyukhovsky, V ORybin, A VNikashin, O PBudanova, M RRosen
Journal: Circulation Research (1992)

We studied the mechanisms underlying the increase in automaticity induced by alpha 1-adrenergic stimulation of normal and  canine Purkinje fibers. Fibers were superfused with a control Tyrode's solution, followed by an ischemic superfusate that included 10 mM KCl, 5 mM NaHCO3, Po2 of 10-25 mm Hg, and pH 6.7. To exclude beta-adrenergic actions, propranolol was added to all solutions. In the presence of phenylephrine, normal automaticity at high membrane potentials usually decreased, whereas the incidence of abnormal automaticity during ischemia was increased from a control value of 10% to 30%. Block of an alpha 1-receptor subtype with chloroethylclonidine in the presence of phenylephrine caused normal automaticity to increase in all fibers studied and significantly increased abnormal automaticity to 70%. The alpha-adrenergic-induced increase in automaticity did not occur in ischemic fibers from animals pretreated with pertussis toxin (PTX), which ADP-ribosylated and functionally inactivated the 4...
Echocardiographic assessment of left ventricular function in mitral valve disease.
Authors: I GMcDonald
Journal: Circulation (1976)

Echocardiography was used to study left ventricular size and contraction in 90 patients with isolated mitral valve disease--47 patients with mitral stenosis, 26 with mixed mitral valve disease and 89 with mitral regurgitation. Left ventricular measurements included the end-diastolic internal dimension (LVIDd), mural thickness (PWTd), an index of circumferential myocardial contraction--fractional shortening (see article)--and stroke volume (LVSV). The left ventricle was abnormally small only when mitral stenosis was severe. Reduced myocardial contraction was common in patients with rheumatic valvular heart disease but was rarely severe. In mitral regurgitation without left ventricular failure, measurements were characteristic of volume overload with increases in LVIDd, LVSV and PWTd which were related to the severity of regurgitation. In other diseases, left ventricular failure is usually associated with reduced myocardial contraction (FS) but in mitral regurgitation with failure, myocardial contraction (F...
Sotatercept for the Treatment of Pulmonary Arterial Hypertension
Authors: Marc Humbert, Vallerie McLaughlin, J. Simon R. Gibbs, Mardi Gomberg-Maitland, Marius M. Hoeper, Ioana R. Preston, Rogerio Souza, Aaron Waxman, Pilar Escribano Subias, Jeremy Feldman, Gisela Meyer, David Montani, Karen M. Olsson, Solaiappan Manimaran, Jennifer Barnes, Peter G. Linde, Janethe de Oliveira Pena, David B. Badesch
Journal: New England Journal of Medicine (2021)

Pulmonary arterial hypertension is characterized by pulmonary vascular remodeling, cellular proliferation, and poor long-term outcomes. Dysfunctional bone morphogenetic protein pathway signaling is associated with both hereditary and idiopathic subtypes. Sotatercept, a novel fusion protein, binds activins and growth differentiation factors in the attempt to restore balance between growth-promoting and growth-inhibiting signaling pathways.In this 24-week multicenter trial, we randomly assigned 106 adults who were receiving background therapy for pulmonary arterial hypertension to receive subcutaneous sotatercept at a dose of 0.3 mg per kilogram of body weight every 3 weeks or 0.7 mg per kilogram every 3 weeks or placebo. The primary end point was the change from baseline to week 24 in pulmonary vascular resistance.Baseline characteristics were similar among the three groups. The least-squares mean difference between the sotatercept 0.3-mg group and the placebo group in the change from baseline to week 24 in pulmonary vascular resistance was -145.8 dyn · sec · cm-5 (95% confidence interval [CI], -241.0 to -50.6; P = 0.003). The least-squares mean difference between the sotatercept 0.7-mg group and the placebo group was -239.5 dyn · sec · cm-5 (95% CI, -329.3 to -149.7; P<0.001). At 24 weeks, the least-squares mean difference between the sotatercept 0.3-mg group and the placebo group in the change from baseline in 6-minute walk distance was 29.4 m (95% CI, 3.8 to 55.0). The least-squares mean difference between the sotatercept 0.7-mg group and the placebo group was 21.4 m (95% CI, -2.8 to 45.7). Sotatercept was also associated with a decrease in N-terminal pro-B-type natriuretic peptide levels. Thrombocytopenia and an increased hemoglobin level were the most common hematologic adverse events. One patient in the sotatercept 0.7-mg group died from cardiac arrest.Treatment with sotatercept resulted in a reduction in pulmonary vascular resistance in patients receiving background therapy for pulmonary arterial hypertension. (Funded by Acceleron Pharma; PULSAR ClinicalTrials.gov number, NCT03496207.).
SRQR and COREQ Reporting Guidelines for Qualitative Studies
Authors: Lesly A. Dossett, Amy H. Kaji, Amalia Cochran
Journal: JAMA Surgery (2021)

This Guide to Statistics and Methods describes Standards for Reporting Qualitative Research (SRQR) and the Consolidated Criteria for Reporting Qualitative Research (COREQ) reporting guidelines for qualitative research.
Dietary treatment of atherosclerosis abolishes hyperresponsiveness to serotonin: implications for vasospasm.
Authors: D DHeistad, A LMark, M LMarcus, D JPiegors, M LArmstrong
Journal: Circulation Research (1987)

Diet-induced atherosclerosis in primates impairs vasodilator responses and greatly potentiates vasoconstrictor responses to serotonin. Serotonin may play an important role in the pathogenesis of vasospasm. In diet-induced regression of atherosclerosis, intimal lesions are reduced, but maximal vasodilator responses do not improve, perhaps because of vascular fibrosis. Our goal was to determine whether dietary treatment of atherosclerosis reverses the augmented vasoconstrictor responses to serotonin and thus might reduce susceptibility to vasospasm. Normal cynomolgus monkeys, atherosclerotic monkeys, and atherosclerotic monkeys that were given a normal (regression) diet for 18 months were studied. Morphometric studies indicated that the regression diet reduced lesions in the iliac and femoral artery since intimal area was reduced by about 50%. In the hind limb perfused at constant flow, residual resistance during maximal vasodilatation produced by infusion of adenosine tended to be greater in atheroscleroti...
Effect of glucose-insulin-potassium infusion on thallium myocardial clearance.
Authors: R AWilson, R DOkada, H WStrauss, G MPohost
Journal: Circulation (1983)

Factors influencing the rate of 201Tl clearance from the myocardium have not been clearly defined. This study determined the effect of an intravenous infusion of glucose-insulin-potassium (GIK) on the net 201Tl clearance rates from myocardium with and without initial 201Tl loading. Anesthetized open-chest dogs underwent 5 min of left anterior descending coronary artery occlusion and intravenous 201Tl was injected and the occlusion released 5 min later. Thirty minutes after 201Tl injection, 30 ml of either GIK (nine dogs) or saline (five dogs) was infused intravenously. The clearance rates of 201Tl from the anterior wall (without initial 201Tl loading) and from the posterior wall (with initial 201Tl loading) were monitored with miniaturized cadmium telluride detectors placed on the myocardium. Calculation of net myocardial clearance rates was performed by linear regression analysis from serial 1 min counts. Compared with saline infusion, GIK increased the net clearance of 201Tl from both myocardial regions...
Art in Endoscopy: Natural analogies
Authors: Francesc Bas-Cutrina, Sandra Maisterra, Joan B. Gornals
Journal: Endoscopy (2021)

This papilla with an impacted stone was observed during ERCP. The image was so extraordinary that we wondered whether any similar image might exist in nature. We therefore contacted an expert in the biological field, Dr. Conxita Avila from the Department of Evolutionary Biology, Ecology and Environmental Sciences, and Biodiversity Research Institute (IrBIO), University of Barcelona. She replied that our image was certainly reminiscent of a marine animal, for example a sponge. There are curious analogies amongst biological forms, as Ernst Haeckel said in his book Kunstformen der Natur [Art Forms in Nature]. Our image of the papilla resembles this one of the Caribbean sponge, Mycale laxissima, https://spongeguide.uncw.edu/imageinfo.php?img=319 (photographer Sven Zea; The Sponge Guide, Universidad Nacional de Colombia).
Morphometric analyses of rabbit thoracic aorta after poststenotic dilatation.
Authors: UKukongviriyapan, B SGow
Journal: Circulation Research (1989)

The aim of this study was to quantify the morphological changes in the arterial wall resulting from poststenotic dilatation (PSD). PSD was produced by placing a split nylon ring around the thoracic aorta of the rabbits at a level of T6-7 during a sterile thoracotomy done under pentobarbital anesthesia. After period of PSD ranging from 1-51 months these rabbits were anesthetized, as were the control animals, and the descending thoracic aorta from the fourth to the eleventh ribs was removed following perfusion fixation with Karnovsky's solution at a constant pressure of 80 mm Hg. The extent of PSD development was variable even though the stenotic ring was the same size in all rabbits. Ultrastructural findings showed degenerative changes of the wall components in the PSD region and were more prominent in the aortas with greater dilatation. Morphometric measurements showed that the PSD was accompanied by a decrease in volume density of both smooth muscle cells (SMCs) and elastin and an increase in collagen an...
Carfilzomib-Based 3-Drug Regimens for Newly Diagnosed Multiple Myeloma—All That Glitters Is Not Gold
Authors: Hamza Hashmi, Zunairah Shah, Faiz Anwer
Journal: JAMA Oncology (2021)

Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy | Continue JAMA Oncology HomeNew OnlineCurrent IssueFor Authors Podcast Publications JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry (1919-1959) JN Learning / CMESubscribeJobsInstitutions / LibrariansReprints & Permissions Terms of Use | Privacy Policy | Accessibility Statement 2023 American Medical Association. All Rights Reserved Search All JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Forum Archive JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry Input Search Term Sign In Individual Sign In Sign inCreate an Account Access through your institution Sign In Purchase Options: Buy this article Rent this article Subscribe to the JAMA Oncology journal
Abstract 11283: A Randomized Controlled Trial Assessing the Efficacy and Safety of Prasugrel for Prevention of Early Saphenous Vein Graft Thrombosis
Authors: Barbara A Danek, Kazeen Abdullah, Aris Karatasakis, Rahel Iwnetu, Kendrick Shunk, Jeffrey Zimmet, Mladen Vidovich, Anthony Bavry, Bavana V Rangan, Michele Roesle, Decebal Griza, Kathleen Stanley, Subhash Banerjee, Houman Khalili, Emmanouil S Brilakis, Shuaib Abdullah
Journal: Circulation (2018)

Introduction: Aortocoronary saphenous vein graft (SVG) failure is common and associated with high morbidity. Thrombus formation may play an important role in early SVG failure. Methods: We performe...
Effect of various plasminogen activators on prostacyclin synthesis in cultured vascular cells.
Authors: HKawaguchi, HYasuda
Journal: Circulation Research (1988)

In this study, we examined the effects of various plasminogen activators on arachidonic acid release and prostacyclin biosynthesis in cultured rat aortic smooth muscle cells and bovine pulmonary artery endothelial cells. Prostacyclin was the major product formed from arachidonic acid in aortic smooth muscle cells and endothelial cells. When intact cells were incubated with streptokinase, one of the plasminogen activators, a significant stimulatory effect on prostacyclin biosynthetic activity in cells was evident without any cellular damage at all concentrations used (1-5,000 units/ml). Streptokinase also caused a marked release of arachidonic acid. However, when it was incubated with cell-free homogenates and [3H]arachidonic acid, it did not show any effects on prostacyclin biosynthesis. The addition of urokinase and tissue-type plasminogen activator had no effect on prostacyclin biosynthesis. Urokinase stimulated the release of arachidonic acid from cells, but it did not show any effect on prostacyclin r...
Diverse mechanisms of unexpected cardiac arrest in advanced heart failure.
Authors: MLuu, W GStevenson, L WStevenson, KBaron, JWalden
Journal: Circulation (1989)

To define the mechanisms of unexpected cardiac arrest in advanced heart failure, we reviewed the causes of cardiac arrest as established from electrocardiographic monitoring and from clinical and autopsy data in patients hospitalized for cardiac transplantation evaluation and management of advanced heart failure (mean left ventricular ejection fraction, 0.18 +/- 0.08) who were stable while on vasodilator and diuretic therapy such that hospital discharge to home was anticipated. Twenty-one cardiac arrests occurred in 20 of 216 (9%) such patients during a 4-year period. Heart failure was due to coronary artery disease with prior myocardial infarction in 13 patients and nonischemic cardiomyopathy in seven patients. The rhythm at the time of arrest was severe bradycardia or electromechanical dissociation (BA/EMD) in 13 (62%) patients. The precipitating cause of the BA/EMD arrest was coronary artery thrombosis or embolism in two patients, pulmonary embolism in one patient, hyperkalemia in two patients, and une...