tbuckley/cabot-search huggingface dataset:
Turbulent blood flow in humans: its primary role in the production of ejection murmurs.
Authors: H NSabbah, P DStein
Journal: Circulation Research (1976)

To clarify the postulate that turbulence may produce ejection murmurs, point velocity and sound were measured in the ascending aorta of 13 subjects: six with normal aortic valves, six with aortic valvular disease, and one with a Bjork-Shiley prosthetic aortic valve. Velocity was measured with a catheter-tip hot film anemometer probe, and sound was measured with a catheter-tip micromanometer. Ejection murmurs detected intra-arterially were always found to be associated with turbulent or highly disturbed flow. Conversely, in the absence of intra-arterial sound during ejection, only minor disturbances of flow were detected. A linear relation between the sound energy density and turbulent energy density was shown (r = 0.92) and a linear relation between the acoustic power output (sound intensity) and turbulent power supply (r = 0.87) also was shown. Studies in vitro of sound and point velocity distal to a porcine valve inserted within a cast of the aorta, which permitted precise centering of the transducers a...
Dose requirements and hemodynamic effects of transdermal nitroglycerin compared with placebo in patients with congestive heart failure.
Authors: R AJordan, LSeith, D AHenry, M MWilen, J AFranciosa
Journal: Circulation (1985)

The dose requirements and duration of effect of transdermal nitroglycerin in patients with heart failure are not clearly established. In a first series of eight patients with chronic heart failure we gave transdermal nitroglycerin in incremental doses until pulmonary capillary wedge pressure fell at least 30% within 4 hr in three consecutive patients. Thus we found that a single dose of 60 mg/24 hr (120 cm2) was the minimal effective dose. Transdermal nitroglycerin or placebo was then given as a single application of 60 mg/24 hr in random double-blind fashion to 15 additional patients with heart failure (eight received transdermal nitroglycerin and seven received placebo), and hemodynamics were monitored for up to 24 hr. After administration of transdermal nitroglycerin, the control pulmonary capillary wedge pressure of 22 +/- 7 mm Hg fell by 6 +/- 6 mm Hg at 2 hr (p less than .05) and reached maximal reduction of 8 +/- 6 mm Hg (p less than .01) at 4 hr. The reduction in wedge pressure remained significan...
Relating extracellular potentials and their derivatives to anisotropic propagation at a microscopic level in human cardiac muscle. Evidence for electrical uncoupling of side-to-side fiber connections with increasing age.
Authors: M SSpach, P CDolber
Journal: Circulation Research (1986)

Elucidation of the mechanisms of cardiac conduction disturbances leading to reentry will require resolution of the details of multidimensional propagation at a microscopic size scale (less than 200 micron). In practice, this will necessitate the combined analysis of extracellular and transmembrane action potentials. The purpose of this paper is to demonstrate the relationships between the time derivatives of the extracellular waveforms and the underlying action potentials in the experimental analysis of anisotropic propagation at this small size scale, and apply these relationships to human atrial muscle at different ages. The extracellular waveforms and their derivatives changed from a smooth contour during transverse propagation in young preparations to complex polyphasic waveforms in the older preparations. The major problem was to estimate the size and location of small groups of fibers that generated the complex waveforms in the older preparations. We found dissimilarities in the derivatives that dis...
Evaluation of the echocardiogram as an epidemiologic tool in an asymptomatic population.
Authors: R SValdez, J AMotta, ELondon, R PMartin, W LHaskell, J WFarquhar, R LPopp, LHorlick
Journal: Circulation (1979)

An asymptomatic adult population of 196 men and women was studied with the echocardiogram to derive age- and sex-specific  values for a number of clinically used echocardiograhic variables. The results are in general agreement with previously published normal values. Body position during the examination, age and sex influence the echocardiographic results; body surface area correction normalized most of these effects. The prevalence of occult abnormalities determined by the echocardiogram is 7%; the most common finding was mitral valve prolapse. Inter- and intraobserver variability was assessed. The interobserver differences found on analysis are statistically, but not clinically , significant. The echocardiogram appears to be a suitable tool to use in epidemiologic studies to detect selected cardiac abnormalities, but is limited for this purpose because some subjects in such a population cannot be adequately examined.
The Alleged Health-Protective Effects of Coffee
Authors: Ang Zhou, Elina Hyppönen
Journal: JAMA Internal Medicine (2018)

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 Internal Medicine 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 Internal Medicine journal
RON Kinase Inhibition Reduces Renal Endothelial Injury in Sickle Cell Disease Mice
Authors: Marina Jerebtsova, Alfia Khaibullina, Elena Afia Adjei, Nowah Kokou Apeadoufia Afangbedji, Andrey Ivanov, Namita Kumari, Zena Quezado, Sergei Nekhai
Journal: Blood (2017)
Delineation Of Barrett’S Neoplasia Using Deep Neural Networks
Authors: M Abdelrahim, M Saikou, N Maeda, E Hossain, S Subramaniam, P Bhandari
Journal: Endoscopy (2021)

Aims Accurate delineation of Barrett’s neoplasia is crucial to detection and planning of endoscopic resection. However, this task can be very challenging. The aim of this study is to develop and validate an artificial intelligence algorithm based on deep neural networks for delineation of Barrett’s neoplasia.
Monitoring and Evaluating Progress towards Universal Health Coverage in India
Authors: Narayanan Devadasan, Soumitra Ghosh, Sunil Nandraj, T. Sundararaman
Journal: PLoS Medicine (2014)

This paper is a country case study for the Universal Health Coverage Collection, organized by WHO. N. Devadasan and colleagues illustrate progress towards UHC and its monitoring and evaluation in India. Please see later in the article for the Editors' Summary
Re: Final Results of an EORTC-GU Cancers Group Randomized Study of Maintenance Bacillus Calmette-Guérin in Intermediate- and High-risk Ta, T1 Papillary Carcinoma of the Urinary Bladder: One-third Dose Versus Full Dose and 1 Year Versus 3 Years of Maintenance
Authors: Eduardo Solsona
Journal: European Urology (2014)
Protective role of intracoronary fatty acid binding protein in ischemic and reperfused myocardium.
Authors: B NSrimani, R MEngelman, RJones, D KDas
Journal: Circulation Research (1990)

In this study, fatty acid binding protein was used to protect an ischemic heart from reperfusion injury. Isolated rat heart was preperfused in the presence of 1.4 microM liposome-bound fatty acid binding protein for 15 minutes, followed by 30 minutes of ischemia and 30 minutes of reperfusion. Our results indicated better preservation of myocardial high-energy phosphate compounds (including ATP and creatine phosphate), reduced creatine kinase and lactate dehydrogenase release from the heart, and improved coronary flow in hearts treated with fatty acid binding protein compared with untreated controls. Fatty acid binding protein enhanced reacylation of arachidonic acid into phospholipids, thereby preserving membrane phospholipids and reducing free fatty acid contents during ischemia and reperfusion. In addition, fatty acid binding protein-bound long-chain free fatty acids and their thioesters as well as carnitine esters were increased in the cytosolic compartment of the heart. These results suggest that fatt...
Augmented cardiopulmonary baroreflex control of forearm vascular resistance in young athletes.
Authors: ATakeshita, SJingu, TImaizumi, YKunihiko, SKoyanagi, MNakamura
Journal: Circulation Research (1986)

The aim of this study was to examine the effect of exercise training on reflex control of vascular resistance in human males. Forearm vascular responses to lower body negative pressure (LBNP) at -10 and -40 mm Hg were compared between highly trained young athletes (21.5 +/- 0.5 years old, n = 14) and age-matched nonathletes (20.7 +/- 0.5 years old, n = 16). Resting heart rate was lower in athletes than in nonathletes. Resting blood pressure, central venous pressure, forearm blood flow, and forearm vascular resistance were not different between the two groups. The magnitude of reflex forearm vasoconstriction in response to LBNP at -10 mm Hg, which decreased central venous pressure but did not alter blood pressure or heart rate, was greater in athletes than in nonathletes. The slope of the regression line relating changes in central venous pressure and forearm vascular resistance was steeper in athletes than in nonathletes. Vasoconstrictive responses to intraarterially administered norepinephrine and angiot...
Increased coronary perforation in the new device era. Incidence, classification, management, and outcome.
Authors: S GEllis, SAjluni, A ZArnold, J JPopma, J ABittl, N LEigler, M JCowley, R ERaymond, R DSafian, P LWhitlow
Journal: Circulation (1994)

BACKGROUNDThe incidence of coronary perforation using new percutaneous revascularization techniques may be increased compared with PTCA. Still, perforation is uncommonly reported, and the optimal management and expected outcome remain unknown. The objectives of the study were to determine the incidence of coronary perforation using balloon angioplasty (percutaneous transluminal coronary angioplasty, PTCA) and new revascularization techniques and to develop optimal strategies for its management based on classification and outcome.METHODS AND RESULTSEleven sites with frequent use of new revascularization devices and prospective coding of consecutive procedures for coronary perforation during 1990 to 1991 contributed to a perforation registry. Patients with perforation were matched by device with an equal-sized cohort without perforation. Data were collected centrally, and all procedural cineangiograms were reviewed at a core angiographic laboratory. A classification scheme based on angiographic appearance o...
The cellular electrophysiologic changes induced by high-energy electrical ablation in canine myocardium.
Authors: J HLevine, J FSpear, H FWeisman, A HKadish, CProod, C OSiu, E NMoore
Journal: Circulation (1986)

High-energy electrical ablation is a new experimental approach to control arrhythmias. In this study, the cellular electrophysiologic effects of high-energy shocks (5 to 40 J) delivered in vitro to 14 epicardial tissues from 11 dogs were studied in an attempt to understand the nature and extent of injury as well as potential arrhythmogenic mechanisms. In addition, this preparation was used to test the importance of cathode-anode configuration, current density, and fiber orientation in the induction of tissue injury in vitro. Electrophysiologic abnormalities were noted up to 10 mm from the electrode wall, and their extent was determined in part by current density and the cathode-anode orientation. A decrease in resting membrane potential, action potential amplitude, and dV/dT occurred in all tissues after high-energy shocks, which was worst nearest the cathode and of graded severity at increasing distances from the cathode. The most severe effects were noted with high current densities and in tissues locat...
Changes in systemic vascular resistance detected by the arterial resistometer: preliminary report of a new method tested during percutaneous transluminal coronary angioplasty.
Authors: RMohr, SRath, OMeir, ASmolinsky, YHar-Zahav, H NNeufeld, D AGoor
Journal: Circulation (1986)

A recently developed apparatus provides on-line continuous monitoring of systemic vascular resistance (SVR) by means of simple computer analysis of the peripheral arterial waveform. The fundamental equation of this method is Ri = P'/(dP/dt), where dP/dt is the peak dP/dt of the peripheral arterial waveform, P' is the pressure at time of peak dP/dt, and Ri is a resistance index that bears a direct relation to SVR. Eleven patients undergoing percutaneous transluminal coronary angioplasty (PTCA) were studied to evaluate the changes in SVR associated with myocardial ischemia (angina detection). There were 49 balloon inflations, all of which were associated with an increase in Ri (from 38.4 +/- 12 to 81.2 +/- 36 X 10(-3) sec; p less than .01) and a decrease in dP/dt (from 2076 +/- 257 to 1327 +/- 326 mm Hg/sec; p less than .01). In 42 of the balloon inflations these changes were associated with electrocardiographic ST-T changes and in 23 it was also associated with anginal pain. When angina was present, a furt...
Respiratory muscle function and dyspnea in patients with chronic congestive heart failure.
Authors: D MMancini, DHenson, JLaManca, SLevine
Journal: Circulation (1992)

BACKGROUNDPatients with heart failure (HF) frequently experience exertional dyspnea. Using near-infrared spectroscopy, we have previously demonstrated accessory respiratory muscle deoxygenation during exercise in these patients by monitoring changes in light absorption at 760-800 nm.METHODS AND RESULTSTo investigate whether low-frequency respiratory muscle fatigue occurs, we performed supramaximal bilateral transcutaneous phrenic nerve stimulation before and after maximal bicycle exercise in 10 patients with HF (age, 62 +/- 10 years; ejection fraction, 18 +/- 7%) and six normal subjects (age, 50 +/- 8 years). Maximal rates of contraction and relaxation, peak twitch tension, and maximal transdiaphragmatic pressure (Pdi) were derived before and after exercise from analysis of six to 12 twitches obtained at functional residual capacity. Pdi, time in inspiration (Ti), time per breath (TTOT), respiratory gases, ratings of perceived dyspnea and fatigue, and 760-800 nm near-infrared spectroscopy absorbency chang...
Fontan procedure for tricuspid atresia.
Authors: A WGale, G KDanielson, D CMcGoon, R BWallace, D DMair
Journal: Circulation (1980)

A Fontan procedure has been performed on 29 patients for tricuspid valvular atresia. The age range was 8 months to 33 years (median 10 years), the pulmonary vascular resistance ranged from 1.8-6.1 units . m2 (mean 3.3 units . m2), and the mean pulmonary arterial pressure ranged from 13-45 mm Hg (mean 21 mm Hg). Twenty-nine previous operations had been performed in 23 patients. Fourteen other associated cardiopulmonary anomalies were present in 12 patients. There were four hospital deaths (13.8%), all in patients with complicating features. Among the last 22 consecutive patients who have undergone operation, one died (4.5%). Complete atrioventricular block necessitated pacemaker implantation in one patient. No late deaths occurred. Of the 19 patients followed 3 months or more from the time of operation, eight have no restriction of exercise capacity, nine have only mild restriction, and two have a poor result. The Fontan approach to tricuspid atresia has several theoretical advantages over previously used ...
The detection of atrial and ventricular septal defects with electrocardiographically synchronized magnetic resonance imaging.
Authors: D GLowell, D ATurner, S MSmith, G HBucheleres, B ASantucci, R JGresick, D OMonson
Journal: Circulation (1986)

To evaluate the detectability of cardiac septal defects by electrocardiographically synchronized (ECG-gated) magnetic resonance imaging (MRI), 48 subjects were imaged, including 18 normal and 30 abnormal subjects in whom 22 ventricular septal defects (VSDs) and nine atrial septal defects (ASDs) had been diagnosed angiographically. Two radiologists with ECG-gated cardiac MRI experience read the scans in a blinded fashion, and the results were evaluated by receiver operator characteristic curve analysis. The detectability of VSDs appeared greater than that of ASDs, although statistical significance at the .05 level was not achieved. The reported sensitivity and specificity of echocardiography in the detection of VSDs is comparable to MRI, whereas echocardiography probably is superior to MRI for detection of ASDs. Although MRI is potentially valuable in the diagnosis of various complex congenital cardiac defects, echocardiography is probably superior in the detection of VSDs and ASDs.
ΔF508 heterozygosity and asthma (multiple letters) [1]
Authors: M. Swift, Y. Su, J. O. Warner, A. B. Lowenfels, P. Maisonneuve, B. Palys, M. H. Schoni, B. Redemann, M. Dahl, A. Tybjaerg-Hansen, P. Lange, B. G. Nordestgaard
Journal: The Lancet (1998)
Shall The Journal be Removed to Washington?
Authors: G. H. Grant
Journal: JAMA (1891)

<h3>THE ACTION OF THE WAYNE COUNTY MEDICAL SOCIETY.</h3> At a regular meeting of the Wayne County (Ind.) Medical Society, held on the 12th inst., Dr. L. C. Johnson moved: That it is the sense of this Society that the office ofThe Journal of the American Medical Associationought not to be removed from Chicago to Washington at this time, and that the delegates from this Society to the next meeting of the American Medical Association are hereby instructed to vote against such removal. After full interchange of views of members on the Subject the motion was unanimously adopted. Richmond, Ind., March 13, 1891.
Fate of intercellular junctions in isolated adult rat cardiac cells.
Authors: FMazet, B AWittenberg, D CSpray
Journal: Circulation Research (1985)

Freeze fracture and thin section techniques have revealed morphological changes in gap junctions and intercalated discs of adult rat myocytes following enzymatic dissociation. Cell separation leaves behind small vesicular remnants of formerly adjacent cells connected to the intact cell by gap junctions; in contrast, desmosomes cleave at the region of intercellular contact. Apparently, the next step in gap junction breakdown is internalization of the remnants. In thin section, lanthanum penetration reveals that the cleft of some apparently internalized gap junctions is in contact with the sarcolemma, while that of others is not. In freeze fracture replicas, cytoplasmic gap junctions frequently possess hexagonally packed domains of E-face pits separated by smooth regions that may correspond to separations of membranes of internalized junctions found in thin section. Study of material maintained overnight at 37 degrees C showed no surface junctional remnants; topologies of cytoplasmic gap junctions were gene...
Catecholamine-dependent atrioventricular nodal reentrant tachycardia.
Authors: R JHariman, J AGomes, NEl-Sherif
Journal: Circulation (1983)

An unusual case of atrioventricular nodal reentrant tachycardia precipitated by ethanol ingestion is presented. Programmed atrial and ventricular stimulation failed to induce the tachycardia during control conditions or after atropine administration. This failure to induce tachycardia was related to the absence of ventriculoatrial conduction. A low-dose isoproterenol infusion allowed induction of atrioventricular nodal reentrant tachycardia by the enhancement of ventriculoatrial conduction. This report suggests that programmed stimulation during isoproterenol infusion can be used to induce paroxysmal supraventricular tachycardia in suspected cases in whom induction during control conditions or after atropine administration is not possible.
Surgical management of large bronchial collateral arteries with pulmonary stenosis or atresia.
Authors: D CMcGoon, D KBaird, G DDavis
Journal: Circulation (1975)

Single or multiple large bronchial collateral arteries may provide all or some of the pulmonary arterial blood flow in patients with proximal atresia of the pulmonary artery, and even in patients with only pulmonary stenosis. At the time of corrective surgery such arteries must be ligated in order to provide favorable operating conditions, to avoid cardiac overdistention during repair, and to prevent left-to-right intrapulmonary shunting postoperatively. Their ligation and control require precise preoperative definition of their number, origin, and course, and special intraoperative methods for their exposure. Associated hypoplasia of the pulmonary arteries may be severe enough to preclude corrective operation, but these hypoplastic arteries may enlarge in response to increase of blood flow through them resulting from a surgically created shunt. Experience with 14 surgically managed cases of this type forms the basis for the report.
Genetic--epidemiologic study of early-onset ischemic heart disease.
Authors: J JNora, R HLortscher, R DSpangler, A HNora, W JKimberling
Journal: Circulation (1980)

A genetic-epidemiologic study was undertaken of a white Colorado population of 207 patients who had a myocardial infarction before age 55 years. Nineteen independent variables were compared between the 207 cases and 621 controls, matched 3:1. The highest risk ratios were associated with a positive family history for ischemic heart disease (IHD). The heritability of IHD was 63% when families with the monogenic forms of hyperlipoproteinemia were included, and 56% when they were excluded. A risk index was developed that incorporates family history into a data base of risk factors, which can be readily assessed by the clinician obtaining a screening history, physical and standard laboratory tests. A scale of 0-10 was devised and the predictive value of the index was tested against another data set. The efficiency of the index was maximal at a screening level of 5. This study suggests that it is logistically feasible to seek patients at high risk for intensive management in a clinical setting (high-risk strate...
Serial angiographic assessment of coronary artery obstruction and collateral flow in acute myocardial infarction. Report from the second Mount Sinai-New York University Reperfusion Trial.
Authors: K PRentrop, FFeit, WSherman, J CThornton
Journal: Circulation (1989)

In the Second Mt. Sinai-New York University Reperfusion Trial, in which change of ejection fraction was the primary end point, the following secondary end points were prospectively assessed by serial coronary angiography: patency of the infarct artery both before intervention and 10-14 days later, acute and delayed recanalization rates, presence or absence of collateral flow, and complication rates of acute interventional catheterization. We assigned 393 patients randomly to groups receiving acute cardiac catheterization and a double-blind intracoronary infusion of streptokinase (SK arm), both streptokinase and nitroglycerin (SK-NTG arm), nitroglycerin alone (NTG arm), or conventional therapy without acute catheterization (control arm). Prospective stratification was based on duration of infarct pain before randomization: group A, less than 2 hours; Group B, 2-12 hours. Baseline patency rates were comparable in patients studied within 6 hours (30%, 40 of 135) and those studied later (24%, 32 of 133). This...