tbuckley/cabot-search huggingface dataset:
Decreased contractile efficiency and increased nonmechanical energy cost in hyperthyroid rabbit heart. Relation between O2 consumption and systolic pressure-volume area or force-time integral.
Authors: YGoto, B KSlinker, M MLeWinter
Journal: Circulation Research (1990)

Both systolic pressure-volume area (PVA) and force-time integral (FTI) have been used as measures of oxygen consumption per beat (VO2) in the isolated left ventricle. The reciprocal of the slope of the VO2-PVA relation has been considered to reflect the chemomechanical energy transduction efficiency of the contractile machinery (contractile efficiency), whereas its VO2 intercept consists of energy cost of excitation-contraction coupling and basal metabolism. To examine whether the increase in myosin isoform V1/V3 ratio in hyperthyroid rabbits decreases contractile efficiency and to determine overall mechanisms of higher oxygen consumption in hyperthyroid hearts, the VO2-PVA and VO2-FTI relations as well as the end-systolic pressure-volume relation were assessed in cross-circulated, isovolumically beating hearts isolated from normal, hyperthyroid, and hypothyroid rabbits. Normalized initial slopes of the rising limb of the curvilinearly fitted end-systolic pressure-volume relation (E'max, ventricular contr...
Radiofrequency catheter ablation of left lateral accessory pathways via the coronary sinus.
Authors: MHaissaguerre, FGaita, BFischer, PEgloff, PLemetayer, J FWarin
Journal: Circulation (1992)

BACKGROUNDThe purpose of this study was to describe a new technique for catheter ablation of left lateral accessory pathways (APs) by radiofrequency energy applied at the epicardium through the coronary sinus wall using a unipolar configuration.METHODS AND RESULTSIn an overall group of 212 patients with left lateral APs, multiple endocardial ablation attempts of the AP were unsuccessful in eight patients. The mean +/- SD cumulative duration of previous attempts was 12 +/- 9 hours, using DC shocks and/or radiofrequency energy applied both at the atrial and/or ventricular AP insertions. Epicardial AP insertion was determined by bipolar and unipolar unfiltered distal electrograms by scanning the coronary sinus with a steerable 6F or 7F catheter with a 4-mm distal electrode. The local atrial to ventricular electrogram amplitude ratio was 0.3-1.6. At the ablation site, the catheter tip was slightly deflected toward the annulus to increase both the ventricular component of electrograms and contact with the epic...
Long-term clinical course and symptomatic status of patients after operation for hypertrophic subaortic stenosis.
Authors: B JMaron, W HMerrill, P AFreier, K MKent, S EEpstein, A GMorrow
Journal: Circulation (1978)

Long-term results of operation for IHSS were reviewed in 124 patients operated upon between 1960 and 1975. Most patients improved symptomatically and manifested marked reduction in LV outflow gradient at rest postoperatively. However, ten (8%) patients died of causes related to operation, 14 (12%) had persistent or recurrent severe functional limitation, and 11 (9%) died up to 13 years postoperatively due to hypertrophic cardiomyopathy. Overall annual mortality rate was 3.5% and was 1.8% for late deaths alone. Of 11 late postoperative deaths, six were sudden and five were due to chronic heart failure. Atrial fibrillation was significantly more common in patients who died late postoperatively than in survivors. Nine of the 11 late deaths had associated medical problems that may have contributed to their outcome. In conclusion, long-lasting clinical improvement occurred in most patients who survived operation for IHSS. However, 12% of patients deteriorated clinically over the 5.2 year average follow-up, and...
Lipoprotein and oxygen transport alterations in passive smoking preadolescent children. The MCV Twin Study.
Authors: W BMoskowitz, MMosteller, R MSchieken, RBossano, J KHewitt, J NBodurtha, J PSegrest
Journal: Circulation (1990)

We investigated the cardiovascular effects of lifelong passive cigarette smoke exposure in preadolescent children and examined the following questions: 1) Is systemic oxygen transport altered? 2) Are coronary heart disease risk factors adversely affected? We recruited 216 families from the MCV Twin Study; 105 had at least one smoking parent. Serum thiocyanate and cotinine levels were used as measures of smoke exposure in the children and thiocyanate was proportional to the number of parental cigarettes smoked each day (p = 0.0001). Paternal smoking had no effect on these measures. Whole blood 2,3-diphosphoglycerate was higher in smoke-exposed than unexposed children (p less than 0.01) and was related to the thiocyanate level (p less than 0.02). High density lipoprotein (HDL) cholesterol was lower in passive smoking children (p less than 0.05); the HDL2 subfraction was reduced in passive smoking boys, while the HDL3 subfraction was reduced in passive smoking girls. Significant adverse alterations in system...
Value of Brush Cytology for Dominant Strictures in Primary Sclerosing Cholangitis
Authors: C Y Ponsioen, S M Vrouenraets, A W van Milligen de Wit, P Sturm, M Tascilar, G J Offerhaus, M Prins, K Huibregtse, G N Tytgat
Journal: Endoscopy (1999)

Background and Study Aims: Around 10 % of patients with primary sclerosing cholangitis (PSC) develop cholangiocarcinoma, which is cholangiographically often indistinguishable from a benign dominant stricture. The aim of the present study was to assess the value of brush cytology in discriminating between benign and malignant dominant strictures in primary sclerosing cholangitis.
Pharmacokinetic studies of taurine in bovine Purkinje fibers.
Authors: S IBaskin, P TZaydon, Z VKendrick, T CKatz, P LOrr
Journal: Circulation Research (1980)

Taurine (2-aminoethane sulfonic acid) is found in high concentrations in the heart, particularly in Purkinje fibers. We studied the transport of taurine in Purkinje fibers that were excised rapidly from the heart and placed in a vessel containing oxygenated Krebs-Henseleit solution (37 degrees C). After equilibration, 4.4 x 10(-6)M radiolabeled taurine[14C] was added to the bath. A computer compartmental analysis of the uptake and efflux indicated the presence of two pools for uptake--a pool with a rapid kinetics K1 (t1/2 = 0.80 min) and K2 (t1/2 = 176.30 min). These studies suggest that Purkinje fibers have the capacity to transport taurine rapidly. Michaelis-Menten procedures showed the presence of a high affinity and a low affinity transport process. Guanidinotaurine, at a 10:1 ratio, had no appreciable effect on taurine uptake, but 3-aminopropane phosphonic acid decreased taurine uptake by 42.7%. Ouabain and acetylstrophanthidin (10(-5) M) inhibited taurine uptake (K1) by 34% and 73%, respectively. Th...
Suppression of chronic ventricular arrhythmias with propranolol.
Authors: R LWoosley, DKornhauser, RSmith, SReele, S BHiggins, A SNies, D GShand, J AOates
Journal: Circulation (1979)

The antiarrhythmic efficacy of propranolol was evaluated in 32 patients with chronic high frequency ventricular arrhythmias in a placebo-controlled protocol. After a placebo control period, propranolol was begun and the dosage increased sequentially until arrhythmia suppression was achieved, side effects appeared, or a maximum dosage of 960 mg/day was reached. Computerized analysis of ambulatory recordings was used to quantify the arrhythmias. Twenty-four patients had 70--100% arrhythmia suppression at plasma levels ranging from 12--1100 ng/ml (end of dosing interval). Eight patients in this group had frequent episodes of ventricular tachycardia that were totally suppressed at or below the dosage that produced greater than or equal to 70% suppression of ventricular ectopic depolarizations (VEDs). A biphasic dose-response curve was seen in five patients who responded with a decrease in arrhythmia frequency in the lower ranges of dosages but had increased frequency of ectopic rhythms as the dosage was incre...
Contraction and relaxation of isolated cardiac myocytes of the frog under varying mechanical loads.
Authors: S SParikh, S ZZou, LTung
Journal: Circulation Research (1993)

The mechanics of cardiac systole and relaxation have been studied primarily at the level of the whole heart or intact muscle. End-systolic pressure-volume relations of frog hearts have been found to be load dependent, whereas those of the mammal are relatively load independent. On the other hand, myocardial relaxation as studied at the muscle level is load independent in the frog but markedly load dependent in the mammal. Interpretation of these studies is complicated because of the unknown contribution of extracellular connective tissue, neurohumoral factors, and, in the case of the heart, the complex chamber geometry. Therefore, it is valuable to study cardiac mechanics at the level of the basic unit of contractile activity--the isolated myocyte. The goal of this study was to subject isolated frog cardiomyocytes to mechanical loading paradigms that mimic those presented to the cells within the heart. In the first part of this study, the afterload and preload of contracting cells were varied to study the...
Increased myocardial adenosine production and reduction of beta-adrenergic contractile response in aged hearts.
Authors: J GDobson, R AFenton, F DRomano
Journal: Circulation Research (1990)

The contractile response of the aged adult heart to beta-adrenergic stimulation is known to be reduced compared with the young adult heart. Since endogenous adenosine exerts an antiadrenergic action in the heart, this study was undertaken to determine if the basal endogenous level of myocardial adenosine increases with age and whether this increase mediates the reduced responsiveness of aged heart to beta-adrenergic stimulation. Young (3-5 months) and aged (12-22 months) Sprague-Dawley adult rat hearts of CD and SD stock were perfused at constant pressure and paced at 270 contractions/min. The two age groups had a similar level of +dP/dtmax (index of contractility) under control conditions. Adenosine release into the coronary effluent was 30 +/- 3 nmol/min/g dry wt from young and 54 +/- 9 nmol/min/g dry wt from aged hearts. Inosine release was also greater from the aged hearts. Isoproterenol (10(-8) M) stimulation increased contractile state by 113% in young hearts and only 69% in aged hearts. Isoproteren...
Treatment and Long-Term Risks for Patients With a Diagnosis of Ductal Carcinoma In Situ
Authors: Virginia Espina, John P. Williams, Lance A. Liotta
Journal: JAMA Oncology (2016)

Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy | Continue JAMA Oncology HomeNew OnlineCurrent IssueFor Authors Podcast Publications JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry (1919-1959) JN Learning / CMESubscribeJobsInstitutions / LibrariansReprints & Permissions Terms of Use | Privacy Policy | Accessibility Statement 2023 American Medical Association. All Rights Reserved Search All JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Forum Archive JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry Input Search Term Sign In Individual Sign In Sign inCreate an Account Access through your institution Sign In Purchase Options: Buy this article Rent this article Subscribe to the JAMA Oncology journal
Relationship between blood pressure of spontaneously hypertensive rats and alterations in membrane properties of mesenteric arteries.
Authors: J WWei, R AJanis, E EDaniel
Journal: Circulation Research (1977)

Spontaneously  rats (SHR) and two strains of normotensive rats were compared with respect to enzymatic activities and calcium accumulation of plasma membrane and endoplasmic reticulum enriched fractions from their mesenteric arteries. Increased specific activities of alkaline phosphatase, 5'-nucleotidase and Mg2+-ATPase, and increased ATP-dependent calcium accumulation were found in 5- to 6-month-old SHR as compared to both strains fo age-matched normotensive rats. Alkaline phosphatase was increased in 33-day-old early hypertensive and 3- to 4-month-old SHR, but 5'-nucleotidase, Mg2+-ATPase, and calcium accumulation were not. Hydralazine treatment of young SHR partially prevented the increase of both alkaline phosphatase activity and blood pressure that develops with age. The relationship between alkaline phosphatase activity and the alterations in vascular reactivity associated with hypertension remains to be determined.
Coronary artery spasm during exercise: treatment with verapamil.
Authors: BFreedman, R FDunn, D RRichmond, D TKelly
Journal: Circulation (1981)

Six patients who had documented coronary spasm and no coronary artery with organic obstruction greater than 50% developed angina and ST-segment elevation on exercise testing. Oral verapamil, 160-480 mg/day, prevented exercise-induced ischemia in all patients and increased maximal work capacity from 611+/- 250 kpm to 808 +/- 160 kpm (p less than 0.02). In two patients, a relationship between the prevention of exercise-provoked ischemia and the plasma concentration of verapamil was demonstrated, and in one of these, the relationship had a diurnal pattern. Patients with variant angina may develop coronary spasm on effort and often respond to verapamil.
Ending the War on Drugs Need Not, and Should Not, Involve Legalizing Supply by a For-Profit Industry
Authors: Jonathan P. Caulkins, Peter Reuter
Journal: The American Journal of Bioethics (2021)

Drug enforcement is unattractive, to put it mildly, particularly in the United States. Few try to defend current U.S. policies, let alone those from before recent reforms.The Bureau of Justice Stat...
Feasibility of altering type A behavior pattern after myocardial infarction. Recurrent Coronary Prevention Project Study: methods, baseline results and preliminary findings.
Authors: MFriedman, C EThoresen, J JGill, DUlmer, LThompson, LPowell, VPrice, S RElek, D DRabin, W SBreall, GPiaget, TDixon, EBourg, R ALevy, D LTasto
Journal: Circulation (1982)

We studied 1035 consecutive postinfarction patients to determine the feasibility of altering type A behavior and the effect such alteration might have on subsequent rates of infarction and cardiovascular death. Approximately 300 subjects were enrolled in small groups and primarily received cardiologic counseling on the usually accepted coronary risk factors. Six hundred subjects received, in addition to cardiologic counseling, advice and instructions designed to diminish the intensity of their type A behavior. The remaining subjects, serving as controls, received no counseling, but were examined and interviewed annually, as were those who dropped out of counseling groups. More than 98% of the 1035 subjects exhibited moderate-to-severe type A behavior during a videotaped structured interview. After the first year of this 5-year study, the rates of infarction and cardiovascular death were lower (p less than 0.01 and p less than 0.05, respectively) among subjects who received both cardiologic and behavioral ...
Spatiotemporal Evolution of Radiation Myositis on 18F-FDG PET/CT Following Hypofractionated Radiotherapy of Intramuscular Melanoma Metastases
Authors: Mathieu Spaas, Bliede Van den Broeck, David Creytens, Vibeke Kruse, Piet Ost
Journal: Clinical Nuclear Medicine (2021)

Abstract Radiation myositis is an infrequent late adverse effect of radiotherapy (RT), more commonly seen after hypofractionated regimens. We present the case of a 52-year-old woman with oligorecurrent metastatic melanoma who, several months after receiving local hypofractionated RT, developed a painful swelling at the irradiated site. As an integral part of routine oncologic follow-up, 18 F-FDG PET/CT allowed accurate visualization of the affected region and when matched with RT treatment plans clearly illustrated their apparent overlap. This case demonstrates the utility of 18 F-FDG PET/CT in the early detection and monitoring of radiation myositis and highlights the importance of a multidisciplinary approach in melanoma care.
Prostaglandin synthesis by glomeruli isolated from rats with glycerol-induced acute renal failure.
Authors: J DSraer, LMoulonguet-Doleris, FDelarue, JSraer, RArdaillou
Journal: Circulation Research (1981)

In vitro PG synthesis by glomeruli isolated from rats with glycerol-induced acute renal failure (ARF) was measured by radiometric high performance liquid chromatography after incubation with [14C]arachidonic acid and radioimmunoassay (RIA). The four PGs, 6-keto-PGF1 alpha, TXB2, PGF2 alpha, and PGE2 were each synthesized by glomeruli from both control and treated rats but the synthesis rates were greater after glycerol. This increase was not apparent 1 hour after injection but, at 24 hours, all PGs were produced in greater amounts by glomeruli of treated rats. Thus, we studied PGE2, PGE2 alpha, and TXB2 synthesis by glomeruli at various time intervals after induction of ARF using direct RIA, PGF 2 alpha and TXB2 synthesis were greater only at 24 hours and only in the presence of arachidonic acid, whereas PGE2 synthesis was greater at 24 hours, irrespective of arachidonic acid, but at 48 hours only with arachidonic acid. The stimulatory effect of arachidonic acid was always greater in glycerol-treated than...
Effects of captopril on ischemic events after myocardial infarction. Results of the Survival and Ventricular Enlargement trial. SAVE Investigators.
Authors: J DRutherford, M APfeffer, L AMoyé, B RDavis, G CFlaker, P RKowey, G ALamas, H SMiller, MPacker, J LRouleau
Journal: Circulation (1994)

BACKGROUNDIn the Survival and Ventricular Enlargement (SAVE) trial, recurrent myocardial infarction (MI) was the most important predictor of a poor outcome and conferred a sevenfold increase in risk of death. The purpose of this study was to determine the predictors of recurrent MI in study participants and to examine the influence of the angiotensin-converting enzyme inhibitor captopril on this and other myocardial ischemic events.METHODS AND RESULTSThe 2231 patients had survived the acute phase of MI (3 to 16 days) and had a radionuclide ventricular ejection fraction < or = 40%. Patients were randomly assigned to receive double-blind treatment with either placebo or captopril and were followed for an average of 42 months. The influence of captopril on recurrent MI, cardiac revascularization procedures, and hospitalization with unstable angina was examined. The likelihood of recurrent MI was greater in patients with an MI or functional disability before the index infarction and higher systolic pressure (...
Less Surgery, Improved Survival From Stage IV Colorectal Cancer?—Reply
Authors: Chung-Yuan Hu, Christina E. Bailey, George J. Chang
Journal: JAMA Surgery (2015)

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
Partition of xenon and iodoantipyrine among erythrocytes, plasma, and myocardium.
Authors: RCarlin, SChien
Journal: Circulation Research (1977)

A new method was developed for determining directly the distribution of 133Xe between red cells and plasma in vitro without an air-fluid interface; the partitioning of 133Xe and 133-i-iodantipyrine between blood and myocardium was investigated in the dog in situ. The red cell-plasma partition coefficient for 133Xe (lambdacpX, unit: ml/ml) at 37 degrees C was 2.27 +/- 0.07 (mean +/- SD) for human blood and 3.31 +/- 0.06 for dog blood. The red cell-plasma partition coefficient for 131I-iodantipyrine (lambdacpI, ml/ml) was 0.75 +/- 0.04 for human blood and 0.97 +/- 0.03 for dog blood. lambdacpX and lambdacpI did not change significantly after the intravenous administration of sodium pentobarbital (30 mg/kg) into the dog. lambdacpX of dog blood varied inversely with temperature, whereas lambdacpI showed very little change with temperature. The blood-left ventricle partition coefficient for 133Xe (lambda'btX, corrected for trapped blood) varied directly with directly with red cell volume fraction (H): lambda'b...
Nitric oxide mediates vasodilatation in response to activation of N-methyl-D-aspartate receptors in brain.
Authors: F MFaraci, K RBreese
Journal: Circulation Research (1993)

Neurons release nitric oxide (NO) in response to activation of receptors for the excitatory amino acid N-methyl-D-aspartate (NMDA). We examined the hypothesis that activation of receptors for NMDA produces dilatation of the cerebral microcirculation that is mediated by NO. Diameters of cerebral arterioles were measured using a closed cranial window in anesthetized rabbits. Under control conditions, topical NMDA produced concentration-related dilatation of pial arterioles. Dilatation in response to NMDA was inhibited selectively by MK-801 (an NMDA receptor antagonist) and tetrodotoxin, suggesting that responses to NMDA were receptor mediated and dependent on neuronal activation. Increases in arteriolar diameter in response to NMDA were not affected by L-arginine but were inhibited by NG-nitro-L-arginine, suggesting that the vasodilatation was mediated by NO. Dilatation of cerebral arterioles in response to NMDA was not inhibited by indomethacin, suggesting that cyclooxygenase products do not mediate the re...
Application of information theory to clinical diagnostic testing. The electrocardiographic stress test.
Authors: G ADiamond, MHirsch, J SForrester, H MStaniloff, RVas, S WHalpern, H JSwan
Journal: Circulation (1981)

The inherent imperfection of clinical diagnostic tests introduces uncertainty into their interpretation. The magnitude of diagnostic uncertainty after any test may be quantified by information theory. THe information content of the electrocardiographic ST-segment response to exercise, relative to the diagnosis of angiographic coronary artery disease, was determined using literature-based pooled estimates of the true- and false-positive rates for various magnitudes of ST depression from less than 0.5 mm to greater than or equal to 2.5 mm. This analysis allows three conclusions of clinical relevance. First, the diagnostic information content of exercise-induced ST-segment depression, interpreted by the standard 1.0-mm criterion, averages only 15% of that of coronary angiography. Second, there is a 41% increase in information content when the specific magnitude of ST-segment depression is analyzed, as opposed to the single, categorical 1-mm criterion. Third, the information obtained from ECG stress testing i...