tbuckley/cabot-search huggingface dataset:
Whole-Arm Ultrasound for Suspected Upper-Extremity Deep Venous Thrombosis in Outpatients
Authors: Marcello Di Nisio, Nick van Es, Harry R. Büller
Journal: JAMA Internal Medicine (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 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
Interaction of the chemoreflex and the pulmonary inflation reflex in the regulation of coronary circulation in conscious dogs.
Authors: S FVatner, R JMcRitchie
Journal: Circulation Research (1975)

The interaction of chemoreflex and pulmonary inflation reflex control of the coronary circulation was examined in conscious dogs by comparing the responses to chemoreflex stimulation (intracarotid injection of nicotine) when ventilation was allowed to increase with those when ventilation was controlled. The responses were also compared with those elicited by both forced mechanical and spontaneous hyperinflation. When the heart rate was constant, intracarotidly administered nicotine induced an increase in the depth of respiration followed closely by an increase in late diastolic coronary flow from 48 +/- 2 to 106 +/- 8 ml/min and a reduction in late diastolic coronary resistance from 1.62 +/- 0.08 to 0.78 +/- 0.06 mm Hg/ml min-1. After beta-receptor and cholinergic blockade, a similar coronary dilation in response to nicotine occurred only when ventilation was allowed to increase. However, when ventilation was controlled, intracarotidly administered nicotine increased coronary resistance after combined bet...
Interstitial dendritic cells of the rat heart. Quantitative and ultrastructural changes in experimental myocardial infarction.
Authors: JZhang, Z XYu, SFujita, M LYamaguchi, V JFerrans
Journal: Circulation (1993)

BACKGROUNDThis study was undertaken to investigate the qualitative and quantitative changes that interstitial dendritic cells (IDC) of the heart undergo during the time course of experimental myocardial infarction.METHODS AND RESULTSLeft coronary arterial ligations were performed in 43 rats that were killed 2, 4, 7, 14, and 21 days after surgery. Thirteen unoperated and 39 sham-operated rats were used as controls. Frozen sections were stained with monoclonal antibodies (OX 6 and W3/25) to identify and count IDC by light microscopy. Immunoelectron microscopy was also used to identify IDC. The number of IDC per mm2 of tissue section was calculated for all hearts. In hearts with myocardial infarction, IDC were counted in three areas: the center of the myocardial infarction, the border zone, and the noninfarcted left ventricle. In OX 6 antibody-stained preparations, the number of IDC per mm2 was 82 +/- 10 in the left ventricle of unoperated rats. Hearts with myocardial infarction showed marked increases in th...
R-wave amplitude variations during acute experimental myocardial ischemia: an inadequate index for changes in intracardiac volume.
Authors: DDavid, MNaito, C CChen, E LMichelson, JMorganroth, MSchaffenburg
Journal: Circulation (1981)

The role of intracardiac volume in controlling electrocardiographic R-wave amplitude changes during acute myocardial ischemia was studied in 24 open-chest dogs. The R-wave amplitude in surface ECG leads 2, V5 and Frank X, Y and Z leads were correlated with hemodynamic, echocardiographic and angiographic changes in a 5-minute circumflex coronary artery ligation and reperfusion model. After coronary ligation, left ventricular end-diastolic diameter and volume increased progressively above control, reached a peak and plateau at 120--130 seconds after ligation and did not return to control levels until more than 5 minutes after release of the occlusion. In contrast, the R-wave amplitude showed a biphasic response to acute ischemia, reaching a nadir (sigma R = 18.2% below control) at 30 seconds after coronary ligation and only subsequently increased to reach a peak (sigma R = 52% above control) at 150 seconds after ligation. In addition, R-wave amplitude returned immediately to control levels within 10 seconds...
The effect of hypoxia on the regional distribution of cardiac output in the dog.
Authors: HAdachi, WStrauss, HOchi, H NWagner
Journal: Circulation Research (1976)

Twenty-one dogs were studied under conditions of normal oxygenation and hypoxia with the microsphere distribution method to determine the effect of arterial oxygen saturation on the regional distribution of cardiac output. The dogs were anesthetized and artifically ventilated. Cannulas were placed in the left ventricle to administer microspheres and in a peripheral artery to determine cardiac output. Each dog received two microsphere injections: (1) while normally oxygenated (room air), and (2) under hypoxia (10% oxygen-90% nitrogen in 10 dogs and 5% oxygen-95% nitrogen in 11 dogs). Absolute cardiac output increased from 87 +/- 15 ml/min per kg to 101 +/- 14 ml/min per kg during mild hypoxia (10% oxygen) (P less than 0.05), and from 73 +/- 17 ml/min per kg to 120 +/- 24 ml/min per kg during severe hypoxia (5% oxygen) (P less than 0.01). Absolute blood flows increased to all organs except skin and muscle during hypoxia, although there were decreases in the fractional distribution of cardiac output to the s...
Effectiveness of Right Heart Catheterization: Time for a Randomized Trial
Authors: Daren Heyland
Journal: JAMA (1997)

To the Editor.  —Dr Connors and colleagues 1 could strengthen their argument that RHC does more harm than good by demonstrating a dose-response relationship. Could the investigators present data that demonstrate that patients who had an RHC placed for longer periods of time fared worse than those who had an RHC placed transiently (eg, less than 24 hours)?
Serial electrophysiologic testing of multiple drugs in patients with atrioventricular nodal reentrant paroxysmal tachycardia.
Authors: R ABauernfeind, C RWyndham, R CDhingra, S PSwiryn, EPalileo, BStrasberg, K MRosen
Journal: Circulation (1980)

Serial electrophysiologic testing of multiple drugs was performed in 21 patients with recurrent atrioventricular (AV) nodal reentrant paroxysmal supraventricular tachycardia (PSVT). All patients had reproducible sustained PSVT induced before drug administration. Serial daily PSVT induction was attempted after administration of i.v. ouabain (0.01 mg/kg) (16 patients), i.v. propranolol (0.1 mg/kg (17 patients), i.v. ouabain + propranolol (same dosages) (12 patients), i.v. procainamide (600-1000 mg) (17 patients) and oral quinidine (1600-2400 mg/day) (nine patients). In two of 21 patients (10%), no tested drug prevented induction of sustained PSVT. In 19 of 21 patients (90%), one or more drugs prevented induction of sustained PSVT: ouabain--seven patients, propranolol--seven patients, ouabain + propranolol--seven patients, procainamide--11 patients, quinidine--seven patients. The site of action of ouabain and/or propranolol was either the antegrade limb or the retrograde limb (RL) of the circus movement. The...
Synergistic effects of acute hypoxemia and hypercapnic acidosis in conscious dogs. Renal dysfunction and activation of the renin-angiotensin system.
Authors: C ERose, D PKimmel, R LGodine, D LKaiser, R MCarey
Journal: Circulation Research (1983)

The effects of acute hypoxemia and hypercapnic acidosis were examined in five unanesthetized dogs in which sodium intake was controlled at 80 mEq/24 hours for 4 days prior to study. Each animal was studied during combined acute hypoxemia and hypercapnic acidosis (Pao2 = 36 +/- 1 mm Hg, Paco2 = 52 +/- 1 mm Hg, pH = 7.18 +/- 0.02), acute hypoxemia alone (Pao2 = 32 +/- 1 mm Hg, Paco2 = 32 +/- 1mm Hg, pH = 7.34 +/- 0.01), and acute hypercapnic acidosis alone (Pao2 = 82 +/- 2 mm Hg, Paco2 = 51 +/- 1 mm Hg, pH = 7.18 +/- 0.02). Although mean arterial pressure, cardiac output, and heart rate increased during combined hypoxemia and hypercapnic acidosis, effective renal plasma flow and glomerular filtration rate decreased. In addition, filtered sodium load and urinary sodium excretion decreased during combined hypoxemia and hypercapnic acidosis. Either acute hypoxemia or hypercapnic acidosis alone resulted in increased mean arterial pressure, cardiac output, and heart rate. However, in contrast to their combined e...
Response to Letter Regarding Article, “Residual Arachidonic Acid–Induced Platelet Activation via an Adenosine Diphosphate–Dependent but Cyclooxygenase-1– and Cyclooxygenase-2–Independent Pathway: A 700-Patient Study of Aspirin Resistance”
Authors: Andrew L. Frelinger, Mark I. Furman, Matthew D. Linden, Youfu Li, Marsha L. Fox, Marc R. Barnard, Alan D. Michelson
Journal: Circulation (2007)
Role of Ca2+ and protein kinase C in shear stress-induced actin depolymerization and endothelin 1 gene expression.
Authors: TMorita, HKurihara, KMaemura, MYoshizumi, RNagai, YYazaki
Journal: Circulation Research (1994)

Vascular endothelial cells adapt to changes in blood flow by altering the cell architecture and by producing various substances. We have previously reported that low shear stress induces endothelin 1 (ET-1) expression in endothelial cells and that this induction is mediated by depolymerization of actin fiber. In the present study, we examined the role of Ca2+ and protein kinase C (PKC) in shear stress-induced actin depolymerization and subsequent ET-1 gene expression. Exposure of cultured porcine aortic endothelial cells to low shear stress (5 dyne/cm2) for 3 hours increased the ratio of G-actin to total actin from 54 +/- 0.8% to 80 +/- 1.0%. This shear stress-induced actin depolymerization was completely blocked by chelation of extracellular Ca2+ with EGTA and partially inhibited by intracellular Ca2+ chelation with the tetraacetoxymethyl ester of BAPTA (BAPTA/AM). Pretreatment with staurosporine, a PKC inhibitor, or desensitization of PKC by treatment with 12-O-tetradecanoylphorbol 13-acetate (TPA) for ...
Prehospital trial of emergency transcutaneous cardiac pacing.
Authors: J RHedges, S ASyverud, W CDalsey, SFeero, REaster, BShultz
Journal: Circulation (1987)

A prospective alternate-day controlled trial of prehospital transcutaneous cardiac pacing (PACE) of hemodynamically significant bradycardia and asystole was undertaken. All patients had a Glasgow coma scale score of 12 or less. Patients in the control group (n = 101) received standard advanced cardiac life support (ACLS) care. Patients in the pacing group (n = 101) were to receive PACE in addition to standard ACLS treatment; 89 patients were actually paced. The two groups were comparable in terms of age, sex, presenting rhythm, and mean times to cardiopulmonary resuscitation (CPR) and ACLS. For the 144 patients in whom the time of arrest could be estimated, the mean times to CPR and ACLS were 5.3 +/- 4.0 and 10.9 +/- 7.1 min, respectively. For the 65 paced patients in whom the time of arrest could be estimated, the mean time from arrest to pacing was 21.8 +/- 8.8 min (range 2 to 43). Multivariate analysis of outcome variables (presentation to emergency department with a pulse, admission to the hospital, a...
Analysis of the characteristics of the flow velocity waveforms in left atrial small arteries and veins in the dog.
Authors: FKajiya, KTsujioka, YOgasawara, OHiramatsu, YWada, MGoto, MYanaka
Journal: Circulation Research (1989)

To clarify the characteristics of the phasic blood velocity pattern in small arteries and veins on the left atrial surface, we used our newly developed fiber-optic laser Doppler velocimeter. We intended particularly to examine the influence of atrial contraction and relaxation on velocity waveforms to obtain some insight into the nature of the mechanical force acting on the atrial intramyocardial vascular beds. In 14 anesthetized open-chest dogs, the left atrial appendage was gently displaced to expose small branches of the artery and vein. Vessels with an outer diameter of about 150-500 microns were chosen for the measurements because their walls are transparent to laser light. The fiber tip (velocity sensor) was fixed on the vessel surface with a drop of cyanoacrylate when good-quality Doppler signals were consistently observed. Additional experiments with three dogs were performed to observe the blood velocities in the atrial artery and vein during arrhythmia. The blood velocity waveform in the artery ...
The role of myeloid‐derived suppressor cells in gastrointestinal cancer
Authors: Cheng Cui, Penglin Lan, Li Fu
Journal: Cancer Communications (2021)

Abstract Gastrointestinal (GI) cancer encompasses a range of malignancies that originate in the digestive system, which together represent the most common form of cancer diagnosed worldwide. However, despite numerous advances in both diagnostics and treatment, the incidence and mortality rate of GI cancer are on the rise. Myeloid‐derived suppressor cells (MDSCs) are a heterogeneous population of immature myeloid cells that increase in number under certain pathological conditions, such as infection and inflammation, and this expansion is of particular relevance to cancer. MDSCs are heavily involved in the regulation of the immune system and act to dampen its response to tumors, favoring the escape of tumor cells from immunosurveillance and increasing both metastasis and recurrence. Several recent studies have supported the use of MDSCs as a prognostic and predictive biomarker in patients with cancer, and potentially as a novel treatment target. In the present review, the mechanisms underlying the immunosuppressive functions of MDSCs are described, and recent researches concerning the involvement of MDSCs in the progression, prognosis, and therapies of GI cancer are reviewed. The aim of this work was to present the development of novel treatments targeting MDSCs in GI cancer in the hope of improving outcomes for patients with this condition.
Cyclic ADP-ribose competes with ATP for the adenine nucleotide binding site on the cardiac ryanodine receptor Ca(2+)-release channel.
Authors: RSitsapesan, S JMcGarry, A JWilliams
Journal: Circulation Research (1994)

We have investigated the mechanism of action of the putative second messenger, cyclic ADP-ribose (cADPR), on the cardiac ryanodine-sensitive Ca(2+)-release channel. Current fluctuations through single Ca(2+)-release channels have been monitored after incorporation into planar phospholipid bilayers. We demonstrate that activation of the channel by cADPR is dependent on activating levels of cytosolic Ca2+ and lifetime analysis indicates that the mechanism of action may be sensitization of the channel to Ca2+. In the absence of ATP, cADPR activates the channel in a concentration-dependent manner in the presence of 10 mumol/L cytosolic Ca2+. However, in the presence of ATP, cADPR tends to decrease open probability, indicating that cADPR may be acting at the adenine nucleotide binding site. In addition, we demonstrate that the precursor of cADPR, beta-NAD+, and the breakdown product, ADP-ribose, also activate the channel. As cADPR will have to compete with much higher concentrations of beta-NAD+, ADP-ribose, a...
Preoperative and postoperative renin levels in coarctation of the aorta.
Authors: F BParker, D HStreeten, BFarrell, M SBlackman, H MSondheimer, G HAnderson
Journal: Circulation (1982)

We studied plasma renin activity (PRA) in eight children before and after surgical correction of aortic coarctation. These eight children underwent a combination of low-sodium diet and diuresis before surgery, and PRA was measured shortly thereafter. Thirty-two to 51 months after successful surgical correction, PRA was measured again. The mean PRA was 21.4 +/- 1.3 ng/ml/hour (+/- SD) preoperatively and 5.5 +/- 1.5 ng/ml/hour postoperatively. These findings provide further evidence of the significance of increased renin-angiotensin activity in patients with aortic coarctation.
An academic backwater?
Authors: G. Bourne, T. Chad, R V Clements, R D de Vere, P. Diggory, D G. Evans, D. Fairbairn, Y B Gordon, P J Hugo, Z Keilani, A Kenney, J. McGrath, P Owen-Simpkins, M. Setchell, D. Williams
Journal: BMJ (1976)
Successful resuscitation of two near simultaneous cases of cardiac arrest with a review of fifteen cases occurring during supervised exercise.
Authors: W FMead, H RPyfer, J CThrombold, R CFrederick
Journal: Circulation (1976)

Two men with coronary heart disease experienced cardiac arrests during a recent exercise rehabilitation session. Fifteen cases of ventricular fibrillation have occurred in this program since 1968, making an average of one per six-thousand man hours of supervised exercise training. All were successfully resuscitated with no sequelae. Analysis of the patients who experience ventricular fibrillation suggests that treating patients with exercise-induced premature ventricular contractions with anti-arrhythmic drugs, proper attention to serum potassium levels, strict adherence to training pulse rates, and proper warm-up might help to prevent future similar events in an exercise program. Due to the unpredictability of ventricular fibrillation it seems preferable that individuals who have known coronary heart disease participate in exercise training under proper supervision with appropriate emergency equipment available.
Intraluminal flow increases vascular tone and 45Ca2+ influx in the rabbit facial vein.
Authors: DHenrion, ILaher, J ABevan
Journal: Circulation Research (1992)

The buccal segment of the rabbit facial vein exhibits a high level of myogenic tone in vitro that develops only in stretched vessel segments between 33 degrees and 44 degrees C. The infusion of physiological salt solution into the lumen of 2-mm-long rabbit facial vein segments induced a flow rate-dependent increase in wall tone, both in the presence (37 degrees C) and absence (30 degrees C) of myogenic tone. In calcium-free physiological solution with EGTA, neither flow nor stretch-induced tone was observed. This flow-induced contraction was associated with an increase in 45Ca2+ unidirectional influx and net uptake. These measurements correlated positively with the level of the associated constrictor responses, both in the presence or absence of myogenic tone. The mean contractile responses to flow (10 and 40 microliters/min), stretch, and histamine (1 microM) were 13%, 28%, 24%, and 33% of the tissue maximal response, respectively. When 45Ca2+ influx was expressed in relation to the force development (45...
Re: Low-Dose Radioactive Iodine Ablation Is Sufficient in Patients With Small Papillary Thyroid Cancer Having Minor Extrathyroidal Extension and Central Lymph Node Metastasis (T3 N1a)
Authors: Mark Tulchinsky
Journal: Clinical Nuclear Medicine (2018)

Section of Nuclear Medicine Department of Radiology Milton S. Hershey Medical Center Penn State University Hershey, PA [email protected] Conflicts of interest and sources of funding: none declared.
QTU prolongation and polymorphic ventricular tachyarrhythmias due to bradycardia-dependent early afterdepolarizations. Afterdepolarizations and ventricular arrhythmias.
Authors: Nel-Sherif, R HZeiler, WCraelius, W BGough, RHenkin
Journal: Circulation Research (1988)

Polymorphic ventricular tachyarrhythmias occurred spontaneously during bradycardia in dogs given the inotropic polypeptide anthopleurin-A (AP-A). The arrhythmia was investigated in in vitro and in vivo experiments. In in vitro experiments, AP-A (50 micrograms/l) produced bradycardia-dependent prolongation of action potential duration that was more pronounced in Purkinje than in muscle fibers. Only Purkinje fibers developed early afterdepolarizations (EAD) and triggered activity. These effects could be abolished by rapid pacing, lidocaine (4 mg/l), or tetrodotoxin (1 mg/l). In vivo experiments were conducted in anesthetized healthy dogs with simultaneous recording of surface ECG, monophasic action potentials from the endocardial and epicardial surface of the left ventricle by contact electrode catheter technique, and transmembrane action potentials from the epicardial surface of the left ventricle with a floating microelectrode technique. AP-A in a dose comparable to that used in vitro (4 micrograms/kg, i....
Ventricular ectopic beats and their relation to sudden and nonsudden cardiac death after myocardial infarction.
Authors: A JMoss, H TDavis, JDeCamilla, L WBayer
Journal: Circulation (1979)

The role of ventricular ectopic beats (VEBs) in identifying patients who die of cardiac cause in the posthospital phase of myocardial infarction was evaluated in 940 patients who survived an acute coronary event. Six-hour Holter ECG recordings were obtained before hospital discharge, and VEBs were classified as complex (bigeminal, multiform, repetitive or R on T), simple (one or more VEBs that did not have complex patterns), or not present. Patients were followed 1-60 months (average 36 months) and cardiac mortality was categorized as sudden (less than or equal to 1 hour) or nonsudden (greater than 1 hour) among 98 witnessed cardiac deaths. Complex VEBs were associated with a significantly increased cardiac death rate, but did not discriminate between sudden and nonsudden death. Simple VEBs were associated with a 3-year cardiac mortality rate intermediate between those with complex and those with no VEBs. The relationship between complex VEBs and cardiac mortality was independent of 10 relevant clinical v...