tbuckley/cabot-search huggingface dataset:
Propagation through electrically coupled cells. Effects of regional changes in membrane properties.
Authors: R WJoyner, JPicone, RVeenstra, DRawling
Journal: Circulation Research (1983)

The normal process of excitation of the heart involves propagation of action potentials through cardiac regions of different anatomy and different intrinsic membrane properties. Although our understanding of these properties is still incomplete, it is well accepted that the parameters measured from a single cell penetration in an electrical syncytium (e.g., action potential duration, rate of rise, and velocity) reflect not only the properties of that cell but also the electrotonic interactions with other cells to which the recorded cell is electrically coupled. We have used simulation techniques to predict the spatial distribution of action potential parameters resulting from discretely localized alterations in the intrinsic membrane properties of some of the cells of an electrical syncytium. We have shown that the resulting spatial distribution is markedly different for alterations in plateau and pacemaker currents vs. rising phase currents, and that other factors, such as the site of stimulation and the...
Aurintricarboxylic acid in a canine model of coronary artery thrombosis.
Authors: JStrony, MPhillips, DBrands, JMoake, BAdelman
Journal: Circulation (1990)

Platelet thrombus formation occurs at sites of severe arterial narrowing where shear stress is elevated. Shear stress appears to induce platelet aggregation in vitro by means of initiation of von Willebrand factor binding to platelet glycoprotein Ib. Recent in vitro studies have demonstrated that aurintricarboxylic acid can inhibit shear stress-induced platelet aggregation. This effect is mediated by aurintricarboxylic acid binding to von Willebrand factor; this binding results in inhibition of von Willebrand factor interaction with glycoprotein Ib. In this study, we examined the effect of aurintricarboxylic acid on platelet-dependent cyclic flow reductions (CFRs) in a canine coronary stenosis model. In dose-response experiments, six animals received 4 mg/kg aurintricarboxylic acid by bolus infusion, followed by 1 mg/kg every 10 minutes. Total inhibition of CFRs was observed in all animals after 6.7 mg/kg aurintricarboxylic acid; CFRs could not be reinitiated by the thromboxane A2 analogue U46619. Continu...
Clinical Crossroads: A 65-Year-Old Man With an Inguinal Hernia
Authors: Joseph B. Vander Veer
Journal: JAMA (1997)

<h3>To the Editor.</h3> —I enjoyed the Clinical Crossroads article by Dr Wantz,<sup>1</sup>but additional information can be helpful in dealing with patients with inguinal hernia and in teaching students and house staff. Patients generally are predisposed to a groin hernia either from an area of weakness (aggravated by aging) or by a congenital defect, factors mentioned by Wantz. A useful question is, "Why did this patient develop this hernia at this time?" because directed questions can uncover other salient problems that need attention. In older men, 4 questions are relevant: (1) Inquire about smpking, because a chronic cough in a smoker can not only precipitate a hernia but compromise the repair if the patient develops pulmonary problems postoperatively. I obtain a chest x-ray in heavy smokers and have discovered lung cancer in 2 patients this way. (2) Ask about precipitating events. Often in an older man, heavy lifting has set the scene
Shall The Journal be Removed to Washington?
Authors: W. W. Reeves
Journal: JAMA (1891)

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
Immunohistochemical delineation of the conduction system. II: The atrioventricular node and Purkinje fibers.
Authors: P WOosthoek, SVirágh, W HLamers, A FMoorman
Journal: Circulation Research (1993)

Using an antibody that reacts specifically with the myocytes of the conduction system of the bovine heart, we have studied the atrioventricular node and the spatial distribution of the Purkinje fibers in the bovine heart. This study was complemented by studying the distribution of the gap junction protein connexin43 in these areas in the bovine heart and in the human heart. The large Purkinje fibers in the bovine heart are arranged in a two-dimensional network underneath the endocardium. At discrete sites, these fibers branch to the Purkinje fibers situated between the muscle bundles of the ventricular mass. These intramural Purkinje fibers are arranged in sheets that form a complex three-dimensional network of lamellas. Contacts with the ventricular myocytes are found throughout the myocardial wall, with the exception of a subepicardial layer of 2-mm thickness, ie, 10% to 15% of the wall thickness. The spatial arrangement of the Purkinje fibers correlates well with data on electrophysiology. Connexin43 w...
Predictive value of tissue plasminogen activator mass concentration on long-term mortality in patients with coronary artery disease. A 7-year follow-up.
Authors: J HJansson, B OOlofsson, T KNilsson
Journal: Circulation (1993)

BACKGROUNDThe fibrinolytic system is part of the defense against thrombotic and cardiovascular events, but so far no study has shown that clinical measurements of fibrinolytic key components such as tissue plasminogen activator (t-PA) or plasminogen activator inhibitor type 1 (PAI-1) have any predictive value beyond 3 years.METHODS AND RESULTSIn 1983 through 1985, 213 consecutive patients with angina pectoris and angiographically verified coronary artery disease were sampled, and the mass concentration of t-PA and the activity of PAI-1 were measured in citrated plasma samples. At a mean follow-up time of 7 years, the all-cause mortality was checked. No patient was lost to follow-up. The data were analyzed by Cox regression, and t-PA mass concentration was found to be the only laboratory risk factor significantly related to mortality in all patients (P < .022) and also in the major subgroup (78% of all patients) subjected to coronary bypass surgery (P < .027). In the latter subgroup, body mass index was al...
Electrocardiographic changes after cardioversion of ventricular arrhythmias.
Authors: S BEysmann, F EMarchlinski, A EBuxton, M EJosephson
Journal: Circulation (1986)

To evaluate rhythm and QRS-T changes after cardioversion of induced ventricular arrhythmias, 56 patients underwent continuous three-lead and serial 12-lead electrocardiographic monitoring for 15 min after 77 cardioversions. Fifty patients were cardioverted externally and nine internally with an implanted automatic cardioverter/defibrillator. Initial energy for external cardioversion was 200 Wsec in 57 of 64 arrhythmia episodes. Two hundred watt-seconds of energy effectively terminated 41 of 44 episodes of ventricular tachycardia and six of 13 episodes of ventricular fibrillation (p less than .001). Early bradycardia (mean cycle length greater than or equal to 1200 msec during the first 5 sec) occurred after 17 of 64 external and two of 13 internal cardioversions (p = NS) in a total of 16 patients. Bradycardia persisted at 10 sec after cardioversion in nine patients. Early bradycardia was associated with the need for multiple cardioversions to terminate the arrhythmia (six of 10 multiple cardioversions vs ...
Pulmonary vascular disease in transposition of the great vessels and intact ventricular septum.
Authors: E ANewfeld, M HPaul, A JMuster, F SIdriss
Journal: Circulation (1979)

Eight of 135 (6%) children with d-transposition of the great vessels and with intact ventricular septum and no patent ductus arteriosus had evidence of progressive pulmonary vascular disease. Seven of 101 (7%) patients for whom histologic data was available, had Heath-Edwards grades IV or V pulmonary vascular disease, six had grade II, and 88 had either normal or grade I findings. One of 34 patients for whom histologic data was not available had hemodynamic evidence of pulmonary vascular disease at cardiac catheterization after the Mustard operation. When infants younger than 3 months old were excluded, eight of 85 (9%) had advanced pulmonary vascular disease. Twenty-three patients had microthrombi in their pulmonary arteries and arterioles, and in one patient thrombi were observed before the development of pulmonary vascular disease. Clinically unrecognized pulmonary microthrombi are suggested as a possible etiologic agent in the development of pulmonary vascular disease in patients with transposition of...
Influence of calcium-entry blockade on vasoconstrictor responses in feline mesenteric vascular bed.
Authors: H LLippton, W MArmstead, A LHyman, P JKadowitz
Journal: Circulation Research (1987)

The subtypes of postjunctional alpha-adrenoceptors activated by neuronally released and exogenous norepinephrine and the source of calcium used for vasoconstrictor responses were investigated in the feline mesenteric vascular bed. Under constant flow conditions, intra-arterial injections of phenylephrine and UK14304, alpha 1- and alpha 2-adrenoceptor agonists, increased mesenteric arterial perfusion pressure in a dose-related manner. Prazosin, an alpha 1-antagonist, reduced vasoconstrictor responses to phenylephrine without altering responses to UK14304. Yohimbine, an alpha 2-antagonist, reduced responses to UK14304 without altering responses to phenylephrine. The same pattern of blockade was observed in animals pretreated with 6-hydroxydopamine to destroy the integrity of adrenergic terminals. Responses to phenylephrine and UK14304 were reduced by nitrendipine, a calcium-entry blocking agent, and this agent decreased vasoconstrictor responses to sympathetic nerve stimulation, tyramine, and norepinephrine...
Assessment of the Severity of Endoscopic Lesions in Ulcerative Colitis: Endoscopist’s Evaluation Versus Ulcerative Colitis Endoscopic Index Score
Authors: A Hammami, A Hassine, F Zinelabidine, Ameur W Ben, W Dahmani, N Elleuch, A Braham, S Ajmi, A Ben Slama, M Ksiaa, H Jaziri, A Jmaa
Journal: Endoscopy (2021)

Aims The aim of this study was to explore the interobserver variation in the assessment of endoscopic lesions in Ulcerative colitis (UC) and to compare it with the UC endoscopic index of severity (UCEIS).
Voltage-dependent gating and single-channel conductance of adult mammalian atrial gap junctions.
Authors: RLal, M FArnsdorf
Journal: Circulation Research (1992)

In the heart, the rapid propagation and synchronization of action potentials necessary for a normal heart rhythm and an effective cardiac output are mediated by specialized ionic channels that link adjacent cells and are known collectively as gap junctions. Cardiac gap junctions are gated by various physiological and pharmacological agents, but the role of voltage in their gating is unclear. Whereas embryonic or neonatal ventricular cells have voltage-gated gap junctions, adult cells are reported to have only voltage-independent gap junctions. We studied the voltage dependence of adult rat atrial gap junctions by individually voltage clamping each cell of a connected cell pair and controlling the transjunctional voltage (Vj), measuring transjunctional current (Ij), and calculating junctional conductance (gj). Two distinct populations of cell pairs were observed: highly coupled pairs with the peak gjs ranging from 3.4 to 40 nS and weakly coupled pairs with the peak gjs ranging from 0.3 to 2.0 nS. gj was de...
Aortoventriculoplasty for tunnel subaortic stenosis and other obstructions of the left ventricular outflow tract. Clinical and hemodynamic results.
Authors: P GBjörnstad, HRastan, JKeutel, A JBeuren, JKoncz
Journal: Circulation (1979)

A new therapeutic concept of enlarging the outflow tracts of both ventricles with a patch and inserting an aortic prosthesis has been developed for the treatment of tunnel subaortic stenosis. This operation has been applied clinically since June 1974 on several types of obstruction in the outflow tract of the left ventricle. Twenty-one operations have been performed on 20 patients under the age of 18 years, with an overall mortality of 24% and no late deaths. Seven patients developed complete right bundle branch block or left anterior hemiblock or both as a result of this operation; transient atrioventricular block and complete left bundle branch block occurred in one patient each. In no case, however, did rhythm disturbances contribute to death. In one patient, the septal incision injured a septal coronary artery, with fatal result. Fourteen patients had catheterization studies postoperatively. Although previous conventional surgery had been unsuccessful, aortoventriculoplasty (AoVPI) reduced the mean gr...
Initial Effects of COVID-19 on Patients with ESKD
Authors: Eric D. Weinhandl, James B. Wetmore, Yi Peng, Jiannong Liu, David T. Gilbertson, Kirsten L. Johansen
Journal: Journal of the American Society of Nephrology (2021)

Reports from around the world have indicated a fatality rate of patients with coronavirus disease 2019 (COVID-19) in the range of 20%-30% among patients with ESKD. Population-level effects of COVID-19 on patients with ESKD in the United States are uncertain.
Tales of How Great Drugs Were Brought Down by a Flawed Rationale—Letter
Authors: Brian J. Tunquist, Kenneth W. Wood, Duncan H. Walker
Journal: Clinical Cancer Research (2013)

In their recently published article ([1][1]), Komlodi-Pasztor and colleagues propose that development of selective mitotic inhibitors is grounded in a flawed therapeutic rationale. The authors argue that the primary determinant of sensitivity is tumor cell proliferation rate, and that these drugs
‘A silent epidemic of grief’: a survey of bereavement care provision in the UK and Ireland during the COVID-19 pandemic
Authors: Caroline Pearce, Jonathan R Honey, Roberta Lovick, Nicola Zapiain Creamer, Claire Henry, Andy Langford, Mark Stobert, Stephen Barclay
Journal: BMJ (2021)

Objectives  To investigate the experiences and views of practitioners in the UK and Ireland concerning changes in bereavement care during the COVID-19 pandemic.  Design  Online survey using a snowball sampling approach.  Setting  Practitioners working in hospitals, hospices, care homes and community settings across the UK and Ireland.  Participants  Health and social care professionals involved in bereavement support.  Interventions  Brief online survey distributed widely across health and social care organisations.  Results  805 respondents working in hospice, community, and hospital settings across the UK and Ireland completed the survey between 3 August and 4 September 2020. Changes to bereavement care practice were reported in: the use of telephone, video and other forms of remote support (90%); supporting people bereaved from non-COVID conditions (76%), from COVID-19 (65%) and people bereaved before the pandemic (61%); funeral arrangements (61%); identifying bereaved people who might need support (56%); managing complex forms of grief (48%) and access to specialist services (41%). Free-text responses demonstrated the complexities and scale of the impact on health and social care services, practitioners and their relationships with bereaved families, and on bereaved people.  Conclusions  The pandemic has created major challenges for the support of bereaved people: increased needs for bereavement care, transition to remote forms of support and the stresses experienced by practitioners, among others. The extent to which services are able to adapt, meet the escalating level of need and help to prevent a 'tsunami of grief' remains to be seen. The pandemic has highlighted the need for bereavement care to be considered an integral part of health and social care provision.
Mental Hygiene in Education
Authors: S R LAYCOCK
Journal: JAMA (1941)

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
Endoscopic Submucosal Dissection and barrett’s ESOPHAGUS - Results of the German ESD Registry
Authors: C Fleischmann, A Probst, A Ebigbo, S Faiss, B Schumacher, M Mende, V Rempel, C Rust, H Messmann
Journal: Endoscopy (2021)

Aims In Europe, endoscopic submucosal dissection (ESD) is not yet the standard treatment for premalignant or early malignant lesions in the gastrointestinal (GI)-tract. High quality data is limited to single center studies. The German ESD registry was set up to evaluate and assess the technical success, curative resection rate, economic aspects as well as long term outcomes of ESD procedures performed in Germany. In this study, we present results of ESD procedures in Barrett’s esophagus (BE) from the German ESD registry.
Effect of weight reduction in moderately overweight patients on recorded ambulatory blood pressure and free cytosolic platelet calcium.
Authors: UScherrer, JNussberger, STorriani, BWaeber, RDarioli, J RHofstetter, H RBrunner
Journal: Circulation (1991)

Although platelet cytosolic calcium has been shown to decrease during pharmacological treatment of hypertension, there is no evidence that cytosolic calcium also falls during a nonpharmacological reduction in blood pressure. To provide such evidence, we examined prospectively the relation between platelet cytosolic calcium and ambulatory blood pressure during weight reduction in moderately overweight (body mass index [BMI] greater than 25), mildly hypertensive individuals. The experimental group (responders: BMI reduction greater than 5%) consisted of 19 patients who lost 8.5 +/- 2.9 kg (mean +/- SD, p less than 0.05) during a 10-week hypocaloric diet, whereas the control group (nonresponders: BMI reduction less than 5%) consisted of 12 patients who showed no relevant change in body weight (-2.0 +/- 1.3 kg) during the same period of time. The moderate weight loss of the responders decreased blood pressure by 14/5 mm Hg (p less than 0.05), as measured by ambulatory monitoring, which renders a placebo effec...
Increased use of high-flow nasal oxygen during bronchoscopy
Authors: Pedro Silva Santos, Cristiana Cruz, Antonio M. Esquinas
Journal: European Respiratory Journal (2016)

High-flow nasal cannula (HFNC) oxygen therapy is increasingly applied in adult patients with acute respiratory failure (ARF) [1–4]. It delivers heated and humidified air providing higher and more expected gas flow rates and fraction inspired oxygen ( F iO2) than traditional oxygen therapy [2]. The patient should be clinically stable before performing bronchoscopy <http://ow.ly/4mIK0W>
Growth of the aortic anastomosis, annulus, and root after the arterial switch procedure performed in infancy.
Authors: MHourihan, S DColan, GWernovsky, UMaheswari, J EMayer, S PSanders
Journal: Circulation (1993)

BACKGROUNDWe investigated the size and growth potential of the neoaortic root and aortic anastomosis after the arterial switch operation (ASO) for D-transposition of the great arteries (D-TGA) performed in infants. Circumferential suture lines connecting the great arteries and extensive surgery on the arterial roots to transplant the coronary arteries are essential parts of the ASO. However, little is known about the growth of the aortic anastomosis, the neoaortic root, and the neoaortic annulus after the ASO performed in infancy.METHODS AND RESULTSSerial echocardiograms on 50 patients with D-TGA who underwent ASO in infancy at our institution were reviewed, and the size of the aortic anastomosis, the neoaortic root, and the neoaortic annulus were compared with similar structures in a group of 312 control subjects. Before surgery, the native pulmonary root (future neoaortic root) was 1.59 SD larger (P < .001) and the native pulmonary annulus (future neoaortic annulus) was 1.4 SD larger (P < .001) in infan...
Rise in chronic defibrillation thresholds in nonthoracotomy implantable defibrillator.
Authors: F JVenditti, D TMartin, GVassolas, SBowen
Journal: Circulation (1994)

BACKGROUNDTo establish the chronic stability of defibrillation thresholds (DFTs) in a transvenous cardioverter/defibrillator (TCD) system, we studied 37 consecutive patients with TCD systems implanted for > 6 months.METHODS AND RESULTSDFT was measured by a step-down method at implant and 2 and 6 months later. The mean ejection fraction was 34.5 +/- 14.3%. Coronary artery disease with previous myocardial infarction was present in 31 patients. The mean DFT rose from 13.3 +/- 4.3 J at implant to 16.5 +/- 4.7 J at 2 months (P   or = 5 J. The observed rise at 2 months persisted in 19 patients. A chronic rise, defined as > or = 5 J rise at 6 months, occurred in 17 patients. Univariate analysis of clinical as well as implant variables revealed no predictors of a rise in DFT in this group.CONCLUSIONSWe conclude that there is...
Endoscopic Ultrasound (EUS) Guided Radiofrequency Ablation (RFA) for Operable Pancreatic Duct Adenocarcinomas (PDAC) in non-operable Patients: Preliminary Experience in 10 Consecutive Patients
Authors: A Dancour, T Golan, G Sheykman, M Benhaim, E Tahover, E Goldin, DM Livovsky, J Schifter
Journal: Endoscopy (2021)

Aims Some patients with “operable PDAC” are not operated due to age, liver metastases or comorbidities. We aimed to investigate the safety and benefit of EUS-guided RFA in these in patients including ablation of oligo-liver metastasis (≤3) during same procedure if present.
Pre-implant n-terminal pro-B-type natriuretic peptide predicts mortality and morbidity following cardiac resynchronization therapy
Authors: Paul William Foley, Kayvan Khadjooi, Shajil Chalil, Russell E. A. Smith, Selvakumar Ramachandran, Michael Frenneaux, Francisco Leyva
Journal: Journal of the American College of Cardiology (2008)