tbuckley/cabot-search huggingface dataset:
Noninvasive measurement of rate of left ventricular relaxation by Doppler echocardiography. Validation with simultaneous cardiac catheterization.
Authors: R ANishimura, R SSchwartz, A JTajik, D RHolmes
Journal: Circulation (1993)

BACKGROUNDThe instantaneous pressure gradient between the left ventricle and left atrium during systole can be calculated from the mitral regurgitation Doppler velocity curve. The purpose of our study was to determine the accuracy of measuring the time constant of relaxation (TAU) derived from the Doppler mitral regurgitation signal by comparing it with simultaneous high-fidelity left ventricular pressure measurements in humans.METHODS AND RESULTSTwenty-five patients had continuous-wave Doppler mitral regurgitation recordings performed with simultaneous high-fidelity left ventricular pressure measurements. Fifteen of these patients had measurements of six to eight beats at various RR intervals. Doppler velocity curves were converted to left ventricular pressure curves by different methods through application of the modified Bernoulli equation at 3-msec intervals. The correlation between catheter-derived and Doppler-derived TAU was best when a zero asymptote and knowledge of the left ventricular end-diasto...
Liver Transplant for Extensive Colorectal Liver Cancer Metastases
Authors: Ralph C. Quillin, Shimul A. Shah
Journal: JAMA Surgery (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 Surgery 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 Surgery journal
Effect of alterations of arterial blood pressure and heart rate on segmental dyskinesis during acute myocardial ischemia and following coronary reperfusion.
Authors: R EKerber, F MAbboud
Journal: Circulation Research (1975)

The effect of alterations of blood pressure and heart rate on segmental dyskinesis induced by coronary artery ligation and the influence of such manipulations on the magnitude of recovery of the syskinetic segment during subsequent coronary artery reperfusion were evaluated in 77 open-chest dogs. Wall motion was recorded by ultrasound reflected directly from the ischemic myocardial segment. Acute ischemia produced characteristic regional abnormalities in wall motion: aneurysmal bulging occurred during isometric contraction and wall velocity was markedly reduced during ventricular ejection. During 69 minutes of ischemia, a control group of dogs underwent no interventions and showed no further changes in wall motion. Tachycardia induced by atrial pacing during ischemia had no significant effect. Arterial hypertension during ischemia caused a marked reduction in wall velocity when methoxamine was used: 14 plus or minus 2 (SE) mm/sec (ischemia alone) to 6 plus or minus 1 mm/sec (ischemia + drug). In contrast,...
Kappa and delta opioid receptor stimulation affects cardiac myocyte function and Ca2+ release from an intracellular pool in myocytes and neurons.
Authors: CVentura, HSpurgeon, E GLakatta, CGuarnieri, M CCapogrossi
Journal: Circulation Research (1992)

We investigated the effects of mu, delta, and kappa opioid receptor stimulation on the contractile properties and cytosolic Ca2+ (Cai) of adult rat left ventricular myocytes. Cells were field-stimulated at 1 Hz in 1.5 mM bathing Ca2+ at 23 degrees C. The mu-agonist [D-Ala2,N-Me-Phe4,Gly5-ol]-enkephalin (10(-5) M) had no effect on the twitch. The delta-agonists methionine enkephalin and leucine enkephalin (10(-10) to 10(-6) M) and the kappa-agonist (trans-(dl)-3,4-dichloro-N-methyl-N-[2-(1-pyrrolidinyl)cyclo-hexyl]- benzeneacetamide)methanesulfonate hydrate (U-50,488H; 10(-7) to 2 x 10(-5) M) had a concentration-dependent negative inotropic action. The sustained decrease in twitch amplitude due to U-50,488H was preceded by a transient increase in contraction. The effects of delta- and kappa-receptor stimulation were antagonized by naloxone and (-)-N-(3-furyl-methyl)-alpha-normetazocine methanesulfonate, respectively. In myocytes loaded with the Ca2+ probe indo-1, the effects of leucine enkephalin (10(-8) M...
Development of dyadic junctional complexes between sarcoplasmic reticulum and plasmalemma in rabbit left ventricular myocardial cells. Morphometric analysis.
Authors: EPage, J LBuecker
Journal: Circulation Research (1981)

Dyadic junctional couplings between cardiac sarcoplasmic reticulum (SR) and plasma membrane presumably are implicated in release of Ca2+ from terminal cisterns of SR during excitation-contraction coupling. We measured the areas of SR and plasma membrane involved in such couplings in late embryonic and neonatal rabbit left ventricles during a developmental period characterized by rapid cell growth and rapid accumulation of myofibrils. By morphometric methods previously applied to adult hearts, it could be shown that from the inception of the nascent T-system the surface density of dyadic couplings at T-tubular plasmalemma exceeds by about four-fold that at the external plasmalemmal envelope. Before the development of a T-system (similar to or approximately 10 days after birth) surface density of dyads, as well as total dyad areas per unit cell volume and per unit myofibrillar volume, increase progressively during embryonic life until they approach constancy at near adult values one day after birth. Constan...
Electrical activity from the sinus node region in conscious dogs.
Authors: R JHariman, B FHoffman, R ENaylor
Journal: Circulation Research (1980)

In an attempt to understand the way automatic cells in the sinus node (SN) control the cardiac rhythm, we studied extracellular electrograms recorded from the SN region in conscious dogs. A SN electrode, containing 48 silver terminals arranged 1.5 mm apart, was implanted over the node, and an indifferent electrode was implanted on the superior vena cava. Through terminals of the SN electrode paired with the vena caval electrode, unipolar electrograms were recorded at 100 microV/cm and with a time constant of 0.1 second. Low amplitude and low frequency deflections (dV/dt less than or equal to 20 mV/sec) which resulted from electrical activity of the node could be differentiated from the more rapid deflections due to atrial electrical activity. Electrical activity due to the inherent automaticity of what appeared to be groups of automatic cells was recognized as a slow negative-going diastolic slope followed by a slow negative-going, or negative and then positive-going, SN potential. Impulse propagation t...
Endothelial dysfunction of the coronary microvasculature is associated with coronary blood flow regulation in patients with early atherosclerosis.
Authors: A MZeiher, HDrexler, HWollschläger, HJust
Journal: Circulation (1991)

BACKGROUNDThe vascular endothelium is capable of regulating tissue perfusion by the release of endothelium-derived relaxing factor to modulate vasomotor tone of the resistance vasculature.METHODS AND RESULTSTo test whether atherosclerosis is associated with a functional abnormality of endothelium-mediated microvascular relaxation affecting coronary blood flow regulation, we compared coronary blood flow responses with cold pressor testing with the response of the coronary vasculature to acetylcholine (an endothelium-dependent vasodilator) and to papaverin (a direct dilator of vascular smooth muscle) in 12 normal control patients and in 19 patients with non-flow-limiting epicardial atherosclerosis (CAD). The drugs were subselectively infused into the left anterior descending coronary artery via a Doppler catheter, and the response in coronary blood flow was assessed by measuring intracoronary blood flow velocity and cross-sectional arterial area (quantitative angiography). Coronary vascular resistance decre...
Dissociation between the electrophysiological properties and total tissue cyclic guanosine monophosphate content of guinea pig atria.
Authors: M JMirro, J CBailey, A MWatanabe
Journal: Circulation Research (1979)

The purpose of this study was to investigate the role of cyclic guanosine monophosphate (cyclic GMP) in mediating the direct electrophysiological effects of acetylcholine in guinea pig atria. Acetylcholine significantly diminished spontaneous rate of right atria without increasing cyclic GMP content. Reductions in rate following acetylcholine were augmented by pretreatment with physostigmine, but cyclic GMP levels remained unchanged. In left atria, acetylcholine significantly shortened action potential duration within 5 seconds (both with and without physostigmine pretreatment), but cyclic GMP content was not significantly elevated. Cyclic GMP levels in right atria were significantly increased in response to acetylcholine when the Ca2+ content of the buffer was elevated from 1.25 mM TO 2.5 MM; however, reductions in automaticity in the right atria were not augmented in the high Ca2+ buffer. Marked increases in cyclic GMP content were produced by Na nitroprusside superfusion without changing automaticity o...
Expression of ventricular-type myosin light chain messenger RNA in spontaneously hypertensive rat atria.
Authors: CKumar, CSaidapet, PDelaney, CMendola, M ASiddiqui
Journal: Circulation Research (1988)

Using cloned DNA probes specific for two isoforms of cardiac myosin light chains (MLCs), nonphosphorylatable MLC1 and phosphorylatable, regulatory MLC2, we have observed that the MLC1 messenger RNA of ventricular type does not appear in detectable amounts in atrial cells of either normotensive Wistar-Kyoto rat strain (WKY) or spontaneously hypertensive rat strain (SHR). The messenger RNA of regulatory isoform of ventricular MLC2, on the other hand, is found in threefold excess in atria of SHR relative to that of age-matched WKY. The increased level of MLC2 messenger RNA is present even in 6-week-old SHR atria where there is no established overloading of the heart. Thus, it appears that the increased expression of the regulatory MLC2 gene in SHR atrial cells is a predetermined event, which, most likely, participates in functional adaptation of the myocardium in response to pressure overload and subsequent hypertrophy.
Spurious Uptake on 68Ga–Prostate-Specific Membrane Antigen PET/CT Due to Ankylosing Spondylitis; A Rare Pitfall in Imaging of Biochemical Recurrence of Prostate Cancer
Authors: Roisin M. Heaney, Ciaran Johnston, Afshin Nasoodi
Journal: Clinical Nuclear Medicine (2021)

Abstract Bone is one of the most common sites of prostate cancer recurrence, and 68 Ga–prostate-specific membrane antigen (PSMA) uptake by benign bone entities poses a diagnostic dilemma. We describe the case of a 60-year-old man with recurrence in a small presacral node on 68 Ga-PSMA PET/CT. Of note, the images also demonstrated bilateral asymmetrical sacroiliac joint uptake. A history of ankylosing spondylitis was subsequently elicited, confirming the radiographic suspicion of sacroiliitis, therefore confirming the nonmalignant nature of 68 Ga-PSMA uptake related to sacroiliitis rather than osseous recurrence from prostate carcinoma. 68 Ga-PSMA uptake may indicate angioneogenesis in sacroiliitis and consequently may be helpful in assessing disease activity and therapy response.
Ponesimod Compared With Teriflunomide in Patients With Relapsing Multiple Sclerosis in the Active-Comparator Phase 3 OPTIMUM Study
Authors: Ludwig Kappos, Robert J. Fox, Michel Burcklen, Mark S. Freedman, Eva K. Havrdová, Brian Hennessy, Reinhard Hohlfeld, Fred Lublin, Xavier Montalban, Carlo Pozzilli, Tatiana Scherz, Daniele D'Ambrosio, Philippe Linscheid, Andrea Vaclavkova, Magdalena Pirozek-Lawniczek, Hilke Kracker, Till Sprenger
Journal: JAMA Neurology (2021)

To our knowledge, the Oral Ponesimod Versus Teriflunomide In Relapsing Multiple Sclerosis (OPTIMUM) trial is the first phase 3 study comparing 2 oral disease-modifying therapies for relapsing multiple sclerosis (RMS).
Measurement of regional wall motion from biplane contrast ventriculograms: a comparison of the 30 degree right anterior oblique and 60 degree left anterior oblique projections in patients with acute myocardial infarction.
Authors: F HSheehan, JSchofer, D GMathey, M AKellett, HSmith, E LBolson, H TDodge
Journal: Circulation (1986)

The value of performing biplane vs single plane analysis of regional wall motion from contrast ventriculograms was determined in 102 patients who received thrombolytic therapy and who underwent biplane ventriculography during acute myocardial infarction (n = 67), at follow-up more than 2 weeks later (n = 80), or both (n = 45). Hypokinesis in the infarct region and hyperkinesis in the noninfarct region were measured by the centerline method in the respective artery territories, which were defined from the data of 62 patients with single-vessel disease and were expressed in units of standard deviations from the mean of 32 normal subjects. Hypokinesis was more severe and extended over a longer segment of the left ventricular contour when measured in the right anterior oblique (RAO) projection in thrombosis of the left anterior descending coronary artery (LAD) but more severe and extensive in the left anterior oblique (LAO) projection in circumflex stenosis. Hyperkinesis opposite the LAD or the circumflex was...
Utility of B-Type Natriuretic Peptide as a Screen for Left Ventricular Dysfunction in Patients With Diabetes
Authors: Robert R. Henry, Alan Maisel
Journal: Diabetes Care (2004)

Liew et al. (1) are correct in their premise that their study likely represents a different population of patients than our study (2). While their study looked at a very early, asymptomatic population of diabetic subjects who were free of overt heart disease or hypertension, our patient population was a Veterans Administration population with many risk factors for heart disease; hence, they are a very high-risk population.

The positive predictive value of …
The UK Colonoscopy Workforce: Analysis Using The National Endoscopy Database (NED)
Authors: D Beaton, P Rogers, L Sharp, R Broughton, M Rutter
Journal: Endoscopy (2021)

Aims The British Society of Gastroenterology (BSG) recommends colonoscopists perform at least 100 procedures annually to maintain competence. The National Endoscopy Database (NED) is a central database which uploads endoscopy procedural data in real time; over 80 % of UK endoscopy sites now upload to NED.
Residual flow to the infarct zone as a determinant of infarct size after direct angioplasty.
Authors: I PClements, T FChristian, S THigano, R JGibbons, B JGersh
Journal: Circulation (1993)

BACKGROUNDIn acute myocardial infarction, residual flow to the infarct zone either through antegrade flow in the infarct-related coronary artery or collateral flow from the non-infarct-related arteries is often present before reperfusion therapy. The purpose of this study was to assess the influence of antegrade flow in the infarct-related artery and/or collateral flow to the infarct zone before successful direct angioplasty on infarct size and myocardial salvage in patients with acute evolving myocardial infarction.METHODS AND RESULTSSixty patients with acute evolving myocardial infarction underwent direct successful angioplasty without prior thrombolytic therapy. The myocardium at risk of infarction, the final infarct size, and myocardial salvage were measured by tomographic perfusion imaging with 99mTc sestamibi. Antegrade flow in the infarct-related artery before intervention was graded according to the Thrombolysis in Myocardial Infarction (TIMI) study group classification. Collateral flow to the inf...
Simulated blood flow and the effects on prostacyclin production in the dog femoral artery.
Authors: TOnohara, KOkadome, SYamamura, SMii, KSugimachi
Journal: Circulation Research (1991)

Effects of blood flow on the production of prostacyclin (PGI2) were examined in the canine femoral artery perfused ex vivo. Each artery was perfused in situ with medium 199, under conditions of simulated blood flow. To simulate the normal and abnormal blood flow waveforms at the same mean flow rate, we developed a flow apparatus capable of making various waveforms by changing the duration when the electromagnetic valve in the circuit was open. Group I (n = 7) was exposed to a steep acceleration waveform followed by a steep deceleration, as the normal flow waveform; group II (n = 7) was exposed to a gentle sloping waveform in the deceleration phase, as the abnormal flow waveform. PGI2 was measured as 6-ketoprostaglandin F1 alpha. PGI2 production was estimated as the cumulative production for the first 5 minutes (acute response) and as the production rate after the first 30 minutes (stable production rate). Under conditions of normal flow, the acute response was 5.87 +/- 2.16 ng/cm2/5 min, whereas under con...
Adenosine 3',5'-cyclic-monophosphate-dependent regulation of alpha 1-adrenergic receptor number in rabbit aortic smooth muscle cells.
Authors: W SColucci
Journal: Circulation Research (1986)

The purpose of this study was to determine whether a cyclic adenosine 3',5'-monophosphate-dependent process can be involved in the regulation of vascular smooth muscle alpha 1-adrenergic receptor responsiveness. Experiments were performed in cultured rabbit aortic smooth muscle cells which were characterized previously according to alpha-adrenergic receptor-binding characteristics and receptor-coupled norepinephrine-stimulated 45Ca++ efflux. The addition of dibutyryl-cyclic adenosine monophosphate to the cell culture medium for 24 hours resulted in a concentration-related decrease in maximal [3H]prazosin-binding capacity (41 +/- 4% decrease with 1 mM dibutyryl-cyclic adenosine monophosphate) without an effect on [3H]prazosin-binding affinity. Prostaglandin E1 (10 microM) and forskolin (10 microM) caused similar decreases in maximal [3H]prazosin-binding capacity, whereas butyrate (1 mM) and dibutyryl-guanosine-3',5' cyclic-monophosphate (1 mM) had no effect. Dibutyryl-cyclic adenosine monophosphate (1 mM) ...
Renal tubular transport of 3H-digoxin in saline diuresis in rats.
Authors: R JRoman, M LKauker
Journal: Circulation Research (1976)

We evaluated urinary excretion and tubular transport of 3H-digoxin by three different methods in anesthetized rats made diuretic by infusion of 2.5% saline. In one group small volumes of 3H-digoxin and 14C-inulin were injected simultaneously into surface proximal convolutions, and urine was collected serially from both ureters. Digoxin recovery was lower after early (62.1 +/- 5.3%) than after late (86.9 +/- 7.7%) proximal administration but inulin recovery was complete (99.6 +/- 2.7%) after all injections. Most of the digoxin was excreted simultaneously with inulin. Delayed recovery was low. In another group of rats digoxin and inulin were applied directly to the capsule of the left kidney. Two-thirds of the recovered digoxin appeared from the left ureter and one-third from the right. The difference (41.9 +/- 7.4%) is an estimate of transtubular digoxin influx. Digoxin excretion preceded inulin only on the left. Digoxin to inulin concentration ratios were 6 times higher from the left than the right, where...
Correspondence on ‘Impact of the COVID-19 pandemic on morbidity and mortality in patients with inflammatory joint diseases and in the general population: a nationwide Swedish cohort study’
Authors: Liang En Wee, Edwin Philip Conceicao, Jing Yuan Tan, Julian Thumboo, Indumathi Venkatachalam
Journal: Annals of the Rheumatic Diseases (2021)

We read with interest the article by Bower et al detailing the impact of the COVID-19 pandemic on mortality and morbidity among patients with rheumatic diseases (RDs).1 Though Bower et al reported that the risks of severe COVID-19-related outcomes among patients with RD, such as increased risk of hospitalisation and death, were largely proportionate to those in the general population and explained by comorbidities, risks of severe COVID-19-related outcomes were still increased among patients with RD.1 Indeed, in a separate cohort of inpatients with systemic lupus erythematosus and concomitant SARS-CoV-2 infection, almost one-fifth required intensive care unit admission.2 Outside the pandemic setting, however, common respiratory viral infections (RVIs), including influenza, still remain a significant cause of morbidity and mortality among patients with RD. Increased influenza incidence has been reported among patients with RD,3 and various anti-RD therapies are associated with increased frequency of RVIs.4 Public health measures, such as influenza vaccination, are hence recommended for RVI prevention in patients with RD,5 though most RVIs are not vaccine-preventable. The COVID-19 pandemic …
High-density lipoprotein cholesterol and cardiovascular disease. Four prospective American studies.
Authors: D JGordon, J LProbstfield, R JGarrison, J DNeaton, W PCastelli, J DKnoke, D RJacobs, SBangdiwala, H ATyroler
Journal: Circulation (1989)

The British Regional Heart Study (BRHS) reported in 1986 that much of the inverse relation of high-density lipoprotein cholesterol (HDLC) and incidence of coronary heart disease was eliminated by covariance adjustment. Using the proportional hazards model and adjusting for age, blood pressure, smoking, body mass index, and low-density lipoprotein cholesterol, we analyzed this relation separately in the Framingham Heart Study (FHS), Lipid Research Clinics Prevalence Mortality Follow-up Study (LRCF) and Coronary Primary Prevention Trial (CPPT), and Multiple Risk Factor Intervention Trial (MRFIT). In CPPT and MRFIT (both randomized trials in middle-age high-risk men), only the control groups were analyzed. A 1-mg/dl (0.026 mM) increment in HDLC was associated with a significant coronary heart disease risk decrement of 2% in men (FHS, CPPT, and MRFIT) and 3% in women (FHS). In LRCF, where only fatal outcomes were documented, a 1-mg/dl increment in HDLC was associated with significant 3.7% (men) and 4.7% (wome...
Systematic Review for the 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA Guideline for the Prevention, Detection, Evaluation, and Management of High Blood Pressure in Adults
Authors: David M. Reboussin, Norrina B. Allen, Michael E. Griswold, Eliseo Guallar, Yuling Hong, Daniel T. Lackland, Edgar (Pete) R. Miller, Tamar Polonsky, Angela M. Thompson-Paul, Suma Vupputuri
Journal: Journal of the American College of Cardiology (2017)