tbuckley/cabot-search huggingface dataset:
Noninvasive estimation of right ventricular systolic pressure by Doppler ultrasound in patients with tricuspid regurgitation.
Authors: P GYock, R LPopp
Journal: Circulation (1984)

We evaluated the accuracy of a noninvasive method for estimating right ventricular systolic pressures in patients with tricuspid regurgitation detected by Doppler ultrasound. Of 62 patients with clinical signs of elevated right-sided pressures, 54 (87%) had jets of tricuspid regurgitation clearly recorded by continuous-wave Doppler ultrasound. By use of the maximum velocity (V) of the regurgitant jet, the systolic pressure gradient (delta P) between right ventricle and right atrium was calculated by the modified Bernoulli equation (delta P = 4V2). Adding the transtricuspid gradient to the mean right atrial pressure (estimated clinically from the jugular veins) gave predictions of right ventricular systolic pressure that correlated well with catheterization values (r = .93, SEE = 8 mm Hg). The tricuspid gradient method provides an accurate and widely applicable method for noninvasive estimation of elevated right ventricular systolic pressures.
Left ventricular function depends on previous beat ejection but not previous beat pressure load.
Authors: B KSlinker, S GShroff, R DKirkpatrick, K BCampbell
Journal: Circulation Research (1991)

Previous beat contraction history, in which the performance of the left ventricle on any one beat is influenced by the mechanical events of the previous beat, may be important in the beat-to-beat regulation of left ventricular performance in the intact cardiovascular system. Prior studies of this phenomenon have established that mechanical events of the previous beat influence the function of the current beat, but it is not known whether the important mechanical influence is exerted by previous beat ejection or previous beat pressure. In addition, the magnitude of the effect of previous beat contraction history on left ventricular performance is unknown. To make these determinations, we performed experiments in six isolated rabbit left ventricle preparations buffer perfused at 30 degrees C. Left ventricular pressure and volume were controlled precisely with a servo-controlled linear motor system. After steady-state ejecting conditions were established by clamping left ventricular ejection pressure at 60% ...
Arterial baroreflex sensitivity, plasma catecholamines, and pressor responsiveness in essential hypertension.
Authors: D SGoldstein
Journal: Circulation (1983)

Arterial baroreflex sensitivity, plasma norepinephrine (NE) and epinephrine (E), and pressor and depressor responses were assessed in 25 patients with essential hypertension and 29 normotensive control subjects. Sensitivity of the cardiac limb of the baroreflex was determined by blood pressure and interbeat interval responses associated with the Valsalva maneuver, externally applied neck suction and pressure, and injection of phenylephrine and nitroglycerin. By all these techniques, patients with essential hypertension had significantly decreased baroreflex sensitivity, even after adjustment for age mismatching between the hypertensive and normotensive groups. Hypertensive patients also had significantly higher mean levels of plasma NE and E in both brachial arterial and antecubital venous blood (246 vs 154 pg/ml arterial NE, 286 vs 184 pg/ml venous NE, 99 vs 55 pg/ml arterial E, and 65 vs 35 pg/ml venous E) and significantly larger pressor responses to injected phenylephrine (30.9 mm Hg/100 micrograms vs...
A PERFECT Biomarker-focused Study of Neoadjuvant IO for Esophagogastric Cancer
Authors: Daniel V.T. Catenacci
Journal: Clinical Cancer Research (2021)

Abstract To evaluate feasibility and efficacy, checkpoint inhibitor atezolizumab was added to neoadjuvant chemoradiotherapy prior to surgery for esophagogastric adenocarcinoma. The approach was deemed feasible, and while it did not demonstrate better clinical outcome to propensity-matched patients, biomarker investigation demonstrated that high inflammation in the sample at baseline predicted therapeutic benefit. See related article by van den Ende et al., p. 3351
The postponed compensatory pause as a manifestation of positive feedback in atrioventricular conduction.
Authors: L BGoldberg, M NLevy, JEdelstein
Journal: Circulation (1975)

A patient with hypertensive cardiovascular disease was found to have unusual varieties of premature atrial and ventricular contractions. If the premature atrial contraction resulted in a greatly prolonged P-R interval, such that the increment in P-R exceeded the decrement in the preceding R-P, the next sinus P wave, occurring after a normal P-P interval, was found to be blocked. Also, numerous interpolated ventricular extrasystoles were observed in which the postextrasystolic P-R intervals were markedly prolonged and in which the compensatory pauses were postponed for one or two beats. We also present data from one dog in which a premature atrial activation produced a chain reaction such that complete A-V block occurred three beats later. We propose that the chain reaction which evoked the delayed block in the dog and the postponed compensatory pauses in the patient reflects the operation of a positive feedback mechanism in A-V conduction. Positive feedback is initiated by an extremely long P-R, which res...
Abstract 10924: Soluble Amyloid Precursor Protein 770 is a Novel Marker for Diagnosis of Acute Coronary Syndrome
Authors: Takayoshi Yamaki, Akiomi Yoshihsa, Makiko Miyata, Satoshi Suzuki, Masayoshi Oikawa, Koichi Sugimoto, Hiroyuki Kunii, Kazuhiko Nakazato, Hitoshi Suzuki, Shu-ichi Saitoh, Shinobu Kitazume, Yasuchika Takeishi
Journal: Circulation (2012)

Background: Developing biomarker to facilitate diagnosis of acute coronary syndrome (ACS) is desired in clinical practice. ACS is a prevalent syndrome, which is caused by endothelial injury, plaque...
Platelet-activating factor and the release of a platelet-derived coronary artery vasodilator substance in the canine.
Authors: C VJackson, W ASchumacher, S LKunkel, E MDriscoll, B RLucchesi
Journal: Circulation Research (1986)

Platelet-activating factor (acetyl-glyceryl-ether-phosphorylcholine; 1-O-alkyl-2-O-acetyl-sn-glycero-3-phosphorylcholine), which is released by stimulated neutrophils and platelets, possesses the ability to alter vascular tone and permeability and to activate various formed blood elements. We have characterized the hemodynamic effects of intracoronary injections of platelet-activating factor and the influences of pharmacological blockade and platelet depletion on its activity. Intracoronary injections of platelet-activating factor produced maximum increases in left circumflex coronary artery blood flow of 55 +/- 8, 52 +/- 8, and 52 +/- 7 ml/min at 0.5, 1.0, and 2.0 nM, respectively. Only modest changes in systemic arterial blood pressure and regional developed isometric contractile force were associated with the intracoronary artery administration of platelet-activating factor over the range of doses studied. The increase in left circumflex coronary artery blood flow in response to platelet-activating fac...
EXCRETION OF UREA
Authors: J R Robinson
Journal: JAMA (1934)

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 HomeNew OnlineCurrent IssueFor Authors Podcasts Clinical Reviews Editors' Summary Medical News Author Interviews More 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 journal
Electrophysiological effects of high cocaine concentrations on intact canine heart. Evidence for modulation by both heart rate and autonomic nervous system.
Authors: C WClarkson, CChang, AStolfi, W JGeorge, SYamasaki, A SPickoff
Journal: Circulation (1993)

BACKGROUNDPrevious clinical reports have suggested that cocaine intoxication may produce severe ventricular arrhythmias due to a direct effect on the heart. However, the effects of high plasma levels of cocaine on the electrophysiology of the heart have not been well characterized and remain poorly understood.METHODS AND RESULTSThe purpose of this study was to characterize the electrophysiological effects of high doses of cocaine on the in situ dog heart. In dogs anesthetized with morphine and alpha-chloralose, cocaine (2-11 micrograms/mL) increased both atrial and ventricular refractory periods and produced rate-dependent increases in atrial, atrioventricular, His-Purkinje, and ventricular conduction intervals. The time constant for the onset of cocaine's conduction slowing effect following a reduction in pacing cycle length from 400 to 260 msec was approximately two beats, and the time constant for diastolic recovery from conduction slowing was approximately 200 msec, which are similar to values reporte...
Coronary calcification and its relation to extracoronary atherosclerosis in asymptomatic hypercholesterolemic men. The PCV METRA Group.
Authors: J LMegnien, VSene, SJeannin, AHernigou, M CPlainfosse, IMerli, VAtger, NMoatti, JLevenson, ASimon
Journal: Circulation (1992)

BACKGROUNDThe prevalence of coronary calcifications and extracoronary plaques was studied in patients with asymptomatic hypercholesterolemia.METHODS AND RESULTSUltrafast computed tomography for coronary calcification (presence or absence: calcium score) and echographic assessment of carotid, aortic, and femoral plaques were performed in 111 hypercholesterolemic men: 65% had coronary calcification, 72% had extracoronary plaque. The two lesions were associated as: 1) compared with subjects without coronary calcification, those with calcification had a higher prevalence of aortic (p less than 0.05) and femoral (p less than 0.01) plaque and of two diseased sites (p less than 0.05); 2) the prevalence of coronary calcification was higher in the presence than in the absence of aortic (p less than 0.05) or femoral (p less than 0.01) plaque and higher in two (p less than 0.01) and three diseased (p less than 0.05) sites than in no diseased site; 3) the calcium score was higher in the presence than in the absence o...
QT interval prolongation predicts cardiovascular mortality in an apparently healthy population.
Authors: E GSchouten, J MDekker, PMeppelink, F JKok, J PVandenbroucke, JPool
Journal: Circulation (1991)

BACKGROUNDIn myocardial infarction patients, heart rate-adjusted QT interval (QTc), an electrocardiographic indicator of sympathetic balance, is prognostic for survival.METHODS AND RESULTSIn a 28-year follow-up, the association between QTc and all-cause, cardiovascular, and ischemic heart disease mortality was studied in a population of 3,091 apparently healthy Dutch civil servants and their spouses, aged 40-65 years, who participated in a medical examination during 1953-1954. Moderate (QTc, 420-440 msec) and extensive (QTc, more than 440 msec) QTc prolongations significantly predict all-cause mortality during the first 15 years among men (adjusted respective relative risks [RRs], 1.5 and 1.7) and among women (RRs, 1.7 and 1.6). In men, cardiovascular (RRs, 1.6 and 1.8) and ischemic heart disease mortality (RRs, 1.8 and 2.1) mainly account for this association. In women, the association cannot be attributed specifically to cardiovascular and ischemic heart disease mortality. RRs for a subpopulation withou...
Transcutaneous oxygen recovery and toe pulse reappearance time in the assessment of peripheral vascular disease.
Authors: H BKram, R AWhite, JTabrisky, P LAppel, A WFleming, W CShoemaker
Journal: Circulation (1985)

The accuracy of measurements of transcutaneous oxygen tension (Ptco2) in the diagnosis of peripheral vascular disease (PVD) may be significantly increased by stressing limb circulation with the use of temporary ischemia. The purpose of this study was to compare the transcutaneous oxygen recovery half-time (TORT) and the toe pulse reappearance time (PRT/2) in a series of patients with symptomatic PVD before and after vascular reconstruction. The TORT was defined as the time required to recover half of the decrease in the limb/chest Ptco2 ratio caused by temporary limb ischemia, and is conceptually comparable to the toe PRT/2, the time required to recover half of the control toe pulse amplitude. Measurement of TORT was found to be more feasible (100% vs 58%) and to have a greater diagnostic yield (100% vs 92%) than that of the toe PRT/2. When measured on the dorsum of the foot, TORT values were found to correlate well with the severity of symptoms of PVD; toe PRT/2 values did not correlate with severity of ...
Inhibition of glycolysis in the denervated dog heart.
Authors: A JDrake, D EPapadoyannis, R GButcher, JStubbs, M INoble
Journal: Circulation Research (1980)

We measured glucose metabolism in five dogs before and 3 weeks after cardiac denervation; after this time myocardial norepinephrine is depleted. The discharge by the myocardium, of 14CO2 from infused 14C-D-glucose (U), decreased following denervation (P = 0.05). The ratio of 14CO2 to total CO2 production, which measured the proportion of glucose to total substrate oxidized, also decreased following denervation (P = 0.05). The inhibition of glucose oxidation by denervation was not due to an increase in arterial lactate concentration. There was an associated increase in myocardial content of fructose-6-phosphate in an additional seven dogs (P < 0.01). We postulate that myocardial tissue norepinephrine is one of the controllers of the activity of phosphofructokinase.
Reinventing the Center for Medicare and Medicaid Innovation
Authors: Donald M. Berwick, Rick Gilfillan
Journal: JAMA (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 HomeNew OnlineCurrent IssueFor Authors 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) Podcasts Clinical Reviews Editors' Summary Medical News Author Interviews More 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 journal
A monoclonal antibody against the platelet glycoprotein IIb/IIIa receptor complex prevents platelet aggregation and thrombosis in a canine model of coronary angioplasty.
Authors: E RBates, M JMcGillem, J KMickelson, BPitt, G BMancini
Journal: Circulation (1991)

BACKGROUNDThe comparative effects of aspirin and F(ab')2 fragments of monoclonal antibody 7E3 against the platelet glycoprotein IIb/IIIa receptor on ex vivo platelet aggregation and in vivo thrombosis were studied in a canine coronary balloon angioplasty model.METHODS AND RESULTSThree groups were studied. Group 1 (n = 8) was pretreated with saline placebo, group 2 (n = 8) was pretreated with 325 mg aspirin, and group 3 (n = 8) was pretreated with 0.8 mg/kg 7E3 F(ab')2. Coronary angioplasty was performed in the left anterior descending coronary artery of open-chest dogs under fluoroscopic control; serial measurements of basal and hyperemic coronary blood flows were then made for 2 hours after application of an external stenosis that decreased hyperemic flow by 50%. There were no significant differences in platelet counts or hemodynamic measurements during the experiments. Platelet aggregation was decreased by treatment: group 1, 64 +/- 13% versus 50 +/- 13% (p = NS); group 2, 57 +/- 4% versus 25 +/- 4% (p ...
Abstract 13262: A Potent and Selective Covalent Inhibitor of JNK Protects Heart from both Ischemia/Reperfusion- and Hypertension-induced Heart Failure
Authors: JinliWang, WanqingSun, YinaMa, GeorgeTechiryan, TinghuZhang, JianmingZhang, JiLi
Journal: Circulation (2014)

Introduction: c-Jun NH2-terminal kinases (JNKs) are critical mediators of a variety of detrimental stimuli including ischemia-reperfusion (I/R) and mechanical stress induced by pressure overload. Recently, we reported that a novel synthesized highly selective JNK inhibitor, JNK-IN-8, can form an ATP site-directed covalent bond with a conserved cysteine residual in all JNKs. Therefore, JNK-IN-8 may be broadly useful as a pharmacological tool for inhibiting JNK-dependent signal transduction that is involved in various pathological conditions. Hypothesis: The potent JNK inhibitor, JNK-IN-8, could act as a cardioprotectant against ischemia/reperfusion (I/R)- or hypertension-induced heart failure. Methods: The effects of JNK-IN-8 were monitored in a mouse I/R models with the left anterior descending coronary artery (LAD) occluded and subsequently released, and a mouse model of trans-aortic constriction (TAC), in which pressure overload hypertrophy was induced in 2 weeks. Results: JNK-IN-8 significantly reduced...
Reduced production of cGMP underlies the loss of endothelium-dependent relaxations in the canine basilar artery after subarachnoid hemorrhage.
Authors: PKim, V BSchini, T MSundt, P MVanhoutte
Journal: Circulation Research (1992)

Endothelium-dependent relaxations are inhibited during chronic vasospasm after subarachnoid hemorrhage in the canine basilar artery, although the luminal release of endothelium-derived relaxing factor (EDRF) is maintained. The present study investigated the mechanisms underlying the impaired vascular reactivity and in particular whether the loss of responsiveness of the smooth muscle to EDRF is due to an impaired production of cGMP. Bradykinin and nitric oxide evoked concentration-dependent relaxations in isolated canine basilar arteries with and without endothelium, respectively, which were reduced in the subarachnoid hemorrhage group. Relaxations evoked by M&B22,948 (an inhibitor of cGMP phosphodiesterases) were smaller, but those evoked by the lipophilic cGMP analogue 8-bromo-cGMP were potentiated slightly in the subarachnoid hemorrhage group. The resting levels of cGMP in rings with endothelium (reflecting the effect of spontaneous release of EDRF) and those evoked by bradykinin in rings with endothel...
Pathophysiology of silent myocardial ischemia during daily life. Hemodynamic evaluation by simultaneous electrocardiographic and blood pressure monitoring.
Authors: P CDeedwania, J RNelson
Journal: Circulation (1990)

The role of myocardial oxygen demand in the genesis of silent myocardial ischemia was evaluated by measuring the heart rate and blood pressure changes preceding the silent ischemic events during daily life in 25 men with proven coronary artery disease. Simultaneous 24-48-hour ambulatory electrocardiographic and blood pressure monitoring were performed during unrestricted daily activities. Of the 92 transient ischemic events recorded during monitoring, 85 (92%) were silent. Sixty-one percent of the silent events were preceded by an increase in the heart rate of 5 beats/min or more. Seventy-three percent of the silent ischemic events showed an average increase of 10 mm Hg in systolic blood pressure within 6 minutes preceding the onset of ST segment depression. The silent ischemic events showed a circadian pattern with a high density (34% of total events) between 6:00 AM and noon. The increase in heart rate and blood pressure paralleled the increase in silent ischemic events during these hours. These results...
Accumulation of 5-hydroxytryptamine leads to dysfunction of adrenergic nerves in canine coronary artery following intimal damage in vivo.
Authors: R ACohen, K MZitnay, R MWeisbrod
Journal: Circulation Research (1987)

Previous in vitro studies have demonstrated that coronary artery adrenergic nerves are a principal site of accumulation of 5-hydroxytryptamine released from aggregating platelets. The purpose of this study was to determine whether 5-hydroxytryptamine is accumulated by adrenergic nerves at sites of endothelial damage and platelet aggregation in vivo. Coronary artery 5-hydroxytryptamine content and response to in vitro adrenergic nerve stimulation were studied in dogs 24 hours following balloon catheter-induced intimal injury. 5-Hydroxytryptamine content was significantly increased in the catheter-damaged arteries, and there was a coincident decrease in the content of norepinephrine. The relaxation caused by acetylcholine was abolished in the catheter-injured arteries, indicating loss of this endothelial cell-mediated function. The normal beta-adrenergic relaxation caused by nerve stimulation was inhibited, and in some cases, contractions resulted; these effects were prevented by serotonergic receptor antag...
Endoscopic Resection By Submucosal Tunneling Versus Endoscopic Excavation Of The Submucosa For Submucosal Of The Esophageal And Stomach Muscularis Propria – Systematic Review And Meta-Analysis
Authors: FL Ponte Neto, VMT Sagae, IB Ribeiro, DTH de Moura, FC Mancini, MB Boghossian, WM Bernardo, E Ide, NT Miyajima, EGH De Moura
Journal: Endoscopy (2021)

Aims Tumors of the submucosa (SMT) present as elevated lesions with intact mucosa. Until the emergence of safe endoscopic resection techniques, surgical resection was the main form of removal. This study aims to compare endoscopic submucosal tunneling (STER) and endoscopic submucosa (ESE) excavation for SMT resection of the muscle itself present in the esophagus and stomach, evaluating complete resection rates, en bloc resection rates, recurrence, perforation, complications, bleeding, procedure time and hospital stay.
Body position, electrode level, and respiration effects on the Frank lead electrocardiogram.
Authors: HRiekkinen, PRautaharju
Journal: Circulation (1976)

Frank lead ECG/VCG changes with deep inspiration, expiration, and body position were investigated in 194 patients, 100 with an old myocardial infarction and the remaining 94 chosen as a representative sample of catheterization laboratory patients with a variety of cardiac conditions. In a subgroup of 144 of the patients, Frank lead records were made both at the fifth and the fourth intercostal space. Diagnostic interpretation was performed using the VA-Pipberger ECG Program. The results indicate that, in general, body position and electrode level influence on mean intervals and orientation angles is negligible. There was a highly significant decrease in the R and Q wave amplitudes in leads X and Z and in the maximum spatial magnitude of QRS when electrodes were shifted from the fifth to the fourth interspace. The most pronounced decrease in ECG/VCG amplitudes took place in deep inspiration while mean orientation angles changed little, with the exception of QRS elevation. However, while mean changes with b...