tbuckley/cabot-search huggingface dataset:
Characterization of spatial patterns of flow within the reperfused myocardium by myocardial contrast echocardiography. Implications in determining extent of myocardial salvage.
Authors: F SVillanueva, W PGlasheen, JSklenar, SKaul
Journal: Circulation (1993)

BACKGROUNDSince myocardial blood flow changes dynamically after reperfusion and since both hyperemia and impairment in microvascular function exist within the acutely reperfused bed, we sought to investigate the role of myocardial contrast echocardiography (MCE) in (1) defining the temporal variability in perfusion patterns after reflow and relating these to microsphere-derived blood flow; (2) differentiating viable from infarcted tissue during different periods of reflow; and (3) defining spatial perfusion patterns within the infarct bed in response to exogenously induced maximal vasodilation and relating these to infarct size and extent of myocardial salvage.METHODS AND RESULTSTwenty-one dogs with 3 hours of left anterior descending coronary artery occlusion and 2 to 3 hours of reflow were studied. MCE was performed at 15 and 45 minutes and 2 and 3 hours after reflow. It was also performed at either 2 or 3 hours after reflow in the presence of 0.56 mg/kg of dipyridamole. Radiolabeled microsphere-derived...
Electrophysiological properties and responses to simulated ischemia in cat ventricular myocytes of endocardial and epicardial origin.
Authors: SKimura, A LBassett, TFurukawa, JCuevas, R JMyerburg
Journal: Circulation Research (1990)

In multicellular preparations, there are differences in action potential configuration between endocardium and epicardium, and electrophysiological alterations induced by ischemia are more drastic in epicardium than in endocardium. The present study was designed to examine electrophysiological properties of single cardiac myocytes enzymatically isolated from the endocardial and epicardial surfaces of the cat left ventricle and to determine whether the differential responses to ischemia of intact tissue occur in single cells. Action potentials recorded from the isolated single cells of epicardial surface had lower action potential amplitude and a prominent notch between phase 1 and phase 2, compared with those of the cells isolated from the endocardial surface; these findings are similar to those in intact endocardial and epicardial preparations. Resting membrane potentials recorded from both endocardial and epicardial single cells were sensitive to the change in extracellular K+ concentration and had prop...
Identification of acute myocardial infarction patients suitable for early hospital discharge after aggressive interventional therapy. Results from the Thrombolysis and Angioplasty in Acute Myocardial Infarction Registry.
Authors: D BMark, KSigmon, E JTopol, D JKereiakes, D BPryor, R JCandela, R MCaliff
Journal: Circulation (1991)

BACKGROUNDVery early (day 4) hospital discharge has recently been proposed for selected patients with acute myocardial infarction (MI). The purpose of this study was to determine the most useful factors for identifying acute MI patients treated with aggressive interventional therapy who could be safely discharged on day 4.METHODS AND RESULTSWe studied 708 patients enrolled in the Thrombolysis and Angioplasty in Acute Myocardial Infarction trials I-III. Patients dying in the first 3 days and those with early (days 1-3) emergency coronary artery bypass graft surgery (CABG), late elective CABG (greater than or equal to day 4), or urgent/emergency CABG resulting from a late elective coronary angioplasty were excluded. The remaining 580 patients were randomly divided into a training sample (group 1) that was used to build a logistic regression model for predicting the absence of a late major complication and a test sample (group 2) that was used to validate this model. For this study, patients were considered ...
What is the best predictor of spontaneous ventricular tachycardia and sudden death after myocardial infarction
Authors: D ARichards, KByth, D LRoss, J BUther
Journal: Circulation (1991)

BACKGROUNDDeath during the first year after myocardial infarction is most commonly due to spontaneous ventricular tachycardia (VT) or fibrillation (VF). The purpose of this study was to compare, in a single cohort of patients, the values of inducible VT, delayed ventricular activation, low left ventricular ejection fraction, high-grade ventricular ectopy, and ST segment displacement on exercise in predicting electrical events (witnessed instantaneous death and spontaneous VT or VF) during the first year after myocardial infarction.METHODS AND RESULTSThree hundred sixty one patients aged less than 71 years underwent electrophysiological study, signal-averaged electrocardiogram, gated blood-pool scan, 24 hour ambulatory electrocardiographic monitoring, and exercise testing 1-2 weeks after myocardial infarction and were then followed up for at least 1 year. There were 34 deaths (eight witnessed instantaneous, 26 other), and nine patients survived one or more episodes of spontaneous VF or VT. Patients with in...
TCTAP A-027 Five-year Clinical Outcomes of Successful Recanalization for Coronary Chronic Total Occlusions in Patients with Versus Without Type 2 Diabetes Mellitus
Authors: Peizhi Wang, Deshan Yuan, Ce Zhang, Yuejin Yang, Runlin Gao, Bo Xu, Jinqing Yuan
Journal: Journal of the American College of Cardiology (2021)
Intensive combination drug therapy of familial hypercholesterolemia with lovastatin, probucol, and colestipol hydrochloride.
Authors: J LWitztum, DSimmons, DSteinberg, W FBeltz, RWeinreb, S GYoung, PLester, NKelly, JJuliano
Journal: Circulation (1989)

Patients with familial hypercholesterolemia (FH) have had a life-long sustained elevation of low-density lipoprotein (LDL) cholesterol levels. Consequently, there is a need to maximally lower their elevated levels, and this usually requires lowering LDL levels more than 50%. Because no single hypolipidemic drug will consistently produce such degrees of lowering, combination drug therapy with two or even three agents is required to produce the desired degree of cholesterol lowering. A prospective trial was designed to determine if combination therapy using three hypolipidemic agents could effectively lower LDL levels in 17 severely affected FH subjects. Colestipol hydrochloride (10 g b.i.d.), probucol (500 mg b.i.d.), and lovastatin (20 or 40 mg b.i.d.) were given to each patient, in varying combinations, over a 25-month period. Lovastatin (40 mg/day) uniformly lowered LDL levels 36%. Probucol lowered LDL only 14% and in a variable manner. The combination of lovastatin and probucol lowered LDL no better th...
Identification and characterization of human myocardial phospholipase A2 from transplant recipients suffering from end-stage ischemic heart disease.
Authors: S LHazen, R WGross
Journal: Circulation Research (1992)

Although numerous studies have implicated accelerated phospholipid catabolism during myocardial ischemia as an important contributor to ischemic membrane dysfunction, no information is currently available on the subcellular distribution, physical properties, or kinetic characteristics of human myocardial phospholipase A2. In this report, we demonstrate that the overwhelming majority (98%) of total phospholipase A2 activity in human myocardium (obtained from transplant recipients) is calcium independent, plasmalogen selective, and is distributed between the microsomal (60-70% of total activity) and cytosolic (30-40% of total activity) fractions. Both human myocardial microsomal and cytosolic phospholipase A2 enzymes 1) preferentially hydrolyze plasmalogen molecular species containing arachidonic acid at the sn-2 position, 2) are recalcitrant to chemical inactivation by the indole-reactive agent parabromophenacyl bromide, 3) are irreversibly inhibited by covalent modification of an essential thiol residue b...
Author Correction: ArchR is a scalable software package for integrative single-cell chromatin accessibility analysis
Authors: Jeffrey M. Granja, M. Ryan Corces, Sarah E. Pierce, S. Tansu Bagdatli, Hani Choudhry, Howard Y. Chang, William J. Greenleaf
Journal: Nature Genetics (2021)

A Correction to this paper has been published: https://doi.org/10.1038/s41588-021-00850-x.
63MO Safety analysis of durvalumab following stereotactic body radiotherapy (SBRT) in early-stage non-small cell lung cancer (NSCLC) patients: A first report of a randomized phase II trial (ASTEROID)
Authors: A. Hallqvist, H. Koyi, L. de Petris, K. Lindberg, S. Farooqi, Å. Helland, A. Wikström, M. Johansson, M. Planck, L. Lindberg, Ø. Yksnøy, B.H. Grønberg, N. Helbekkmo, J. Nyman
Journal: Journal of Thoracic Oncology (2021)
Etomoxir, a carnitine palmitoyltransferase I inhibitor, protects hearts from fatty acid-induced ischemic injury independent of changes in long chain acylcarnitine.
Authors: G DLopaschuk, S RWall, P MOlley, N JDavies
Journal: Circulation Research (1988)

Fatty acids are known to increase the severity of injury during acute myocardial ischemia. In this study, we determined the effects of a carnitine palmitoyltransferase I inhibitor, ethyl 2-[6-(4-chlorophenoxy)hexyl]oxirane-2-carboxylate (Etomoxir) on reperfusion recovery of fatty acid perfused hearts. Following a 25-minute period of global ischemia, isolated working hearts reperfused with 1.2 mM palmitate, 11 mM glucose exhibited depressed function compared to hearts perfused with 11 mM glucose alone. A low dose of Etomoxir (10(-9) M) decreased long chain acylcarnitine and long chain acyl-coenzyme A (CoA) levels but did not prevent depressed function. In contrast, a high dose of Etomoxir (10(-6) M) prevented the palmitate-induced depression of function but did not decrease myocardial long chain acylcarnitine or long chain acyl-CoA levels. At this high dose of Etomoxir, oxygen consumption per unit work was decreased during reperfusion recovery, and ATP and creatine-phosphate levels were significantly highe...
Insignificant bilateral convergence of preganglionic vagal fibers on postganglionic neurons to the canine heart.
Authors: S ALang, HZieske, M NLevy
Journal: Circulation Research (1990)

We determined the extent of convergence of preganglionic fibers from the right and left vagus nerves on postganglionic neurons that supply the sinoatrial node in chloralose-anesthetized dogs. We administered hemicholinium-3 and stimulated the right vagus nerve at a high frequency to deplete acetylcholine from the postganglionic parasympathetic neurons supplied by that nerve. We compared the effects of this  regimen with the responses in two control groups: a stimulation control group, which was subjected to high-frequency right vagus stimulation only, and a drug control group, which received a hemicholinium-3 infusion only. The effects of right vagus stimulation did not differ from those of left vagus stimulation in either of the control groups. In the animals subjected to the depletion regimen, the responses to right vagus stimulation were almost abolished. However, the left vagus nerve retained its ability to prolong cardiac cycle length in these animals. Thus, our experiments indicate that l...
Angiotensin (A I, A II, A III) receptor characterization. Correlation of prostaglandin release with peptide degradation.
Authors: A LBlumberg, KNishikawa, S EDenny, G RMarshall, PNeedleman
Journal: Circulation Research (1977)

We examined the ability of the angiotensins (A I, A II, A III) to release a prostaglandin E (PGE)-like substance in the isolated Krebs' perfused kidney and mesenteric vasculature of the rabbit by parallel bioassay. In the kidney, the order of potency for PGE release was A II greater than A III greater than A I with ED50's of 36, 100, and 500 pmol, respectively. In the mesenteric preparation, on the other hand, the order of potency was A III greater than A II greater than A I with ED50's of 75, 125, and 500 pmol, respectively. During one transit through the kidney 72-76% of bioassayable A I and A II was degraded. A III was 89% metabolized. In contrast, the mesenteric vasculature inactivated only 27% of A II and 23% of A III. This data suggests an inverse relationship between renal peptide degradation and PGE release. For characterization of the renal angiotensin receptor-mediating PGE release, dissociation constants (KB) of the competitive angiotensin antagonists [IIe7]-A III and [Sar1, IIe3]-A II were det...
Reducing Low-Value Care and Improving Health Care Value
Authors: Allison H. Oakes, Thomas R. Radomski
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
Corrected sinus node recovery time. Experimental physiologic and pathologic determinants.
Authors: K DChadda, V SBanka, M MBodenheimer, R HHelfant
Journal: Circulation (1975)

To determine the factors affecting reproducibility of sinus node recovery time, the effects of basic pacing rate, pacing duration, milliamperage, vagal and beta-adrenergic stimulation, and sinud node injury, as well as its instantaneous and daily reproducibility, were studied in 36 anesthetized dogs. Corrected sinus node recovery time (CSNRT) showed a mean variation of 9.8 plus or minus 0.4 msec at an atrial pacing rate of 200 beats/min and 29.8 plus or minus 8 msec at an atrial pacing rate of 140 beats/min (P smaller than 0.05). CSNRT increased progressively from 55.4 plus or minus 10 msec to 103.7 plus or minus 13 msec with increase in pacing rate from 140 beats/min to 200 beats/min. It was reproducible when atrial pacing was carried out for 1-5 min, although a wide variation (10-30 msec) was seen from 7-60 minutes (P smaller than 0.05). This measurement was reproducible on two consecutive days and was unaffected by changes in milliamperage. Vagal stimulation consistently prolonged the CSNRT while beta-...
PCCRC Cases Identified Using Population-Based Data May Be Re-Classified As Detected Cancers When Local Data Is Used To Perform A Root Cause Analysis
Authors: A Ahmad, A Humphries, A Dhillon, M Kabir, B Saunders, A Wilson, S Thomas-Gibson
Journal: Endoscopy (2021)

Aims A recent population-based cohort study showed variation in post-colonoscopy colorectal cancer (PCCRC) rates across providers. Aim: to analyse PCCRC cases using local data in order to determine the cause and evaluate whether clinician and/or patient factors are primarily responsible.
Endothelin-1 enhances calcium entry through T-type calcium channels in cultured neonatal rat ventricular myocytes.
Authors: TFurukawa, HIto, JNitta, MTsujino, SAdachi, MHiroe, FMarumo, TSawanobori, MHiraoka
Journal: Circulation Research (1992)

Endothelin-1 (ET-1), a 21-amino acid vasoconstrictive peptide, increases intracellular Ca2+ level and has hypertrophic action on ventricular myocytes. To elucidate a possible role of Ca2+ entry through sarcolemmal Ca2+ channels on this ET-1 action, we examined effects of ET-1 on L-type (ICa,L) and T-type (ICa,T) Ca2+ currents in cultured neonatal rat ventricular myocytes using the patch-clamp technique. ET-1 at a concentration of 10 nM increased the maximum current density of ICa,T from -3.0 +/- 1.4 microA/cm2 in the control condition to -4.4 +/- 1.6 microA/cm2 (p < 0.01). Although the peak amplitude of ICa,L was decreased during ET-1 application (from -9.7 +/- 1.9 microA/cm2 in the control condition to -5.0 +/- 1.4 microA/cm2 [p < 0.01]), this magnitude of decrease in ICa,T (52 +/- 19%) was comparable to that of spontaneous run-down of ICa,L (47 +/- 26%). The enhancement of ICa,T by ET-1 was dose dependent; it was initiated as low as 0.32 nM, and the maximal response was attained at approximately 10 nM...
Dynamic stiffness of barium-contractured cardiac muscles with different speeds of contraction.
Authors: TShibata, W CHunter, KSagawa
Journal: Circulation Research (1987)

The dynamic stiffness of excised cardiac muscles that would be likely to have different intrinsic speeds of contraction, as judged by previous biochemical reports of their myosin ATPase rates, was compared. This study included muscles from thyrotoxic rabbits and newborn rabbits, rabbit atria, and normal papillary muscles at different temperatures. The usual excitation-contraction coupling process was bypassed by replacing bathing Ca2+ with Ba2+. The ensuring actively maintained contracture allowed us to focus more specifically on the contractile properties of the myofilaments. Dynamic stiffness was determined by sinusoidally oscillating muscle length at many different frequencies over the range 0.05-50 Hz while holding average muscle length at 95% of the systolic length, thus giving maximal developed force. The form of the stiffness modulus spectrum was similar for all muscles studied: stiffness was fairly constant at low frequencies, decreased to a minimum at an intermediate frequency, and then increased...
Effects of intracoronary acetylcholine and atropine on basal and dobutamine-stimulated left ventricular contractility.
Authors: J SLandzberg, J DParker, D FGauthier, W SColucci
Journal: Circulation (1994)

BACKGROUNDThe role of cholinergic pathways in modulating left ventricular contractile function in humans is not known. This study evaluated the effect of a cholinergic agonist (acetylcholine) and antagonist (atropine) on basal and beta-adrenergically stimulated left ventricular contractile function in normal subjects and subjects with denervated hearts after cardiac transplantation.METHODS AND RESULTSSix subjects with normal left ventricular function and seven subjects who were 1 to 3 years after cardiac transplantation were studied. Acetylcholine, atropine, and the beta-adrenergic agonist dobutamine were infused via the left main coronary artery, and changes in left ventricular contractile function were assessed by measurement of peak +dP/dt. Intracoronary dobutamine increased +dP/dt by 70 +/- 15% and 66 +/- 20% in the normal subjects and transplant recipients, respectively. Intracoronary acetylcholine and atropine alone each had no effect on left ventricular +dP/dt in either normal subjects or transplan...
Covid-19 in Endoscopy: How Likely is Trasnmission of Infection? Results from an International, Multicenter Study
Authors: I Papanikolaou, A Chatzidakis, K Miltiadou, A Facciorusso, SF Crinò, P Gkolfakis, G Deriban, M Tadic, G Hauser, A Vezakis, I Jovanovic, N Muscatiello, A Meneghetti, G Tziatzios, K Stardelova, A Lacković, MZ Bourou, S Djuranovic, K Triantafyllou
Journal: Endoscopy (2021)

Aims COVID-19 has significantly affected endoscopic practice, as GI-endoscopy is considered a risky procedure for transmission of infection towards personnel of endoscopy units (PEU) and patients. ESGE recommended reduction of non-emergency endoscopies, personal protection measures (PPM) and post-endoscopy calls to patients, to check their COVID-19 status. This study aimed to assess the impact of COVID-19 on endoscopy during the first European lockdown (March-May 2020).
Inappropriate Drug Prescribing
Authors: David C. Klonoff
Journal: JAMA (1995)

To the Editor.  —Dr Willcox and colleagues 1 defined  inappropriate drugs for the community-dwelling elderly and then measured their frequency of use in such a population. We feel the authors made unsubstantiated claims in their title, methods, and conclusion. We found the title misleading and sensational. Whereas the body of the article repeatedly referred to potentially inappropriate prescribing practices, the word potentially was not used in the title. This omission could influence physicians to deprive patients of contraindicated drugs that are  inappropriate for some patients, but appropriate for other patients.  In the Methods section, the authors selected their contraindicated drugs based on the criteria of a prior article that evaluated inappropriate medication use in nursing home residents. 2 Willcox et al, however, studied community-dwelling elderly, not nursing home residents. Compared with the community-dwelling elderly, nursing home residents are generally more frail and have almost twice the prescription rate
Myocardial uptake of 111In monoclonal antimyosin Fab in detecting doxorubicin cardiotoxicity in rats. Morphological and hemodynamic findings.
Authors: MHiroe, YOhta, NFujita, MNagata, TToyozaki, KKusakabe, MSekiguchi, FMarumo
Journal: Circulation (1992)

BACKGROUNDThe therapeutic value of doxorubicin (DOX) is limited by its cardiotoxicity, which is dose dependent. To improve the detection of such myocardial damage, this study was designed to determine whether the 111In antimyosin antibody Fab could serve as a marker for cardiotoxicity in treated versus control rats on the basis of comparative morphological and hemodynamic findings.METHODS AND RESULTSDOX was administered by intravenous injection to rats at a dose of 3 mg.kg-1.week-1 for 5 weeks. Three weeks after the final injection, an intravenous dose of 111In antimyosin, 740 kBq (20 microCi), was administered, and tissue distribution of the radioisotope (percent kilogram dose per gram) was assessed in 48 hours. Myocardial uptake of radioactivity by both ventricles was more prominent in the DOX-treated rats than in control rats (p < 0.001). The heart-to-blood and heart-to-lung uptake ratios were markedly higher in the treated rats than in controls (p < 0.001). As the severity of the myocardial damage inc...
Transmural myocardial deformation in the ischemic canine left ventricle.
Authors: F JVillarreal, W YLew, L KWaldman, J WCovell
Journal: Circulation Research (1991)

The myocardium is a complex three-dimensional structure consisting of myocytes interconnected by a dense collagen weave that courses in different directions. Regional ischemia can be expected to produce complex changes in ventricular deformation. In the present study, we examined the effects of ischemia on two- and three-dimensional finite strains during acute transmural myocardial ischemia in 13 open-chest anesthetized dogs. In contrast to systolic deformation observed during the control period in which circumferential shortening exceeded longitudinal shortening, our results indicate that after 5 minutes of acute ischemia, end-systolic in-plane lengthening across the left ventricular wall occurs in approximately equal amounts in the circumferential and longitudinal directions. Along with these changes in extensional strains, there were significant negative transverse shearing deformations during ischemia. Myocardial ischemia also resulted in a loss of the normal end-systolic transmural gradients of short...