tbuckley/cabot-search huggingface dataset:
Test of a model of antiarrhythmic drug action. Effects of quinidine and lidocaine on myocardial conduction.
Authors: LHondeghem, B GKatzung
Journal: Circulation (1980)

The effects of quinidine and lidocaine on the maximum upstroke velocity (Vmax) of the ventricular myocardial action potential were compared with the effects predicted by a model over a wide range of driving rates, rhythm disturbances and holding potentials. These rate-, rhythm- and voltage-dependent effects were accurately predicted by the proposed model. The model was also able to predict several previously undocumented properties of the drugs: 1) If lidocaine decreases Vmax of a pulse train, the steady state is reached within a few action potentials. 2) The poststimulation recovery of Vmax in the presence of lidocaine or quinidine can occur in a multiexponential fashion, if the membrane potential is kept at the potential where both the fast (operating mainly at more negative membrane potentials) and the slow (operating at more positive potentials) recovery processes are operative. 3) Hyperpolarization markedly attenuates the rate-dependent drug effects. 4) Combinations of lidocaine and quinidine have a ...
Periods of altered risk for non-fatal drug overdose: a self-controlled case series
Authors: Claire Keen, Stuart A Kinner, Jesse T Young, Kathryn Snow, Bin Zhao, Wenqi Gan, Amanda K Slaunwhite
Journal: The Lancet Public Health (2021)

BackgroundBeing recently released from prison or discharged from hospital, or being dispensed opioids, benzodiazepines, or antipsychotics have been associated with an increased risk of fatal drug overdose. This study aimed to examine the association between these periods and non-fatal drug overdose using a within-person design.MethodsIn this self-controlled case series, we used data from the provincial health insurance client roster to identify a 20% random sample of residents (aged ≥10 years) in British Columbia, Canada between Jan 1, 2015, and Dec 31, 2017 (n=921 346). Individuals aged younger than 10 years as of Jan 1, 2015, or who did not have their sex recorded in the client roster were excluded. We used linked provincial health and correctional records to identify a cohort of individuals who had a non-fatal overdose resulting in medical care during this time period, and key exposures, including periods of incarceration, admission to hospital, emergency department care, and supply of medications for opioid use disorder (MOUD), opioids for pain (unrelated to MOUD), benzodiazepines, and antipsychotics. Using a self-controlled case series, we examined the association between the time periods during and after each of these exposures and the incidence of non-fatal overdose with case-only, conditional Poisson regression analysis. Sensitivity analyses included recurrent overdoses and pre-exposure risk periods.FindingsWe identified 4149 individuals who had a non-fatal overdose in 2015–17. Compared with unexposed periods (ie, all follow-up time that was not part of a designated risk period for each exposure), the incidence of non-fatal overdose was higher on the day of admission to prison (adjusted incidence rate ratio [aIRR] 2·76 [95% CI 1·51–5·04]), at 1–2 weeks (2·92 [2·37–3·61]), and 3–4 weeks (1·34 [1·01–1·78]) after release from prison, 1–2 weeks after discharge from hospital (1·35 [1·11–1·63]), when being dispensed opioids for pain (after ≥4 weeks) or benzodiazepines (entire use period), and from 3 weeks after discontinuing antipsychotics. The incidence of non-fatal overdose was reduced during use of MOUD (aIRRs ranging from 0·33 [0·26–0·42] to 0·41 [0·25–0·67]) and when in prison (0·12 [0·08–0·19]).InterpretationExpanding access to and increasing support for stable and long-term medication for the management of opioid use disorder, improving continuity of care when transitioning between service systems, and ensuring safe prescribing and medication monitoring processes for medications that reduce respiratory function (eg, benzodiazepines) could decrease the incidence of non-fatal overdose.FundingMurdoch Children's Research Institute and National Health and Medical Research Council.
Rectorrhagia on Known Hemorrhoidal Pathology in Patients Aged 45 And Above: Interest of Colonoscopy
Authors: R Harbi, S Mrabet, S Zaouga, I Akkari, Jazia E Ben
Journal: Endoscopy (2021)

Aims Rectorrhagia is the usual clinical expression of hemorrhoidal disease and it is a frequent reason for consultation in gastroenterology. Classically, rectorrhagia requires endoscopic exploration mainly in the elderly patients in front of the increased risk of colorectal cancer and hemorrhoidal etiology remains an elimination diagnosis.
Comparative circulatory effects of isoproterenol, dopamine, and dobutamine in conscious lambs with and without aortopulmonary left-to-right shunts.
Authors: G PToorop, RHardjowijono, MDalinghaus, J HKoers, C RWildevuur, W GZijlstra, J RKuipers
Journal: Circulation (1987)

We studied the effect on the circulation of the catecholamines isoproterenol, dopamine, and dobutamine in chronically instrumented lambs with aortopulmonary left-to-right shunts (ages 11 to 87 days) and without shunts (ages 8 to 97 days). Infusion of 0.1 microgram/kg/min isoproterenol or 10 micrograms/kg/min dobutamine markedly increased heart rate and systemic and pulmonary blood flows, while stroke volume and the left-to-right shunt flow did not change. Since pulmonary blood flow increased and the left-to-right shunt flow did not change, the left-to-right shunt fraction decreased with the infusions of isoproterenol and dobutamine. The hemodynamic changes during the infusion of isoproterenol and dobutamine occurred immediately after the start of infusion and stabilized within a few minutes. The pattern of hemodynamic changes was not influenced by the presence of an aortopulmonary left-to-right shunt or by age. Infusion of 10 micrograms/kg/min dopamine caused only small hemodynamic changes. This study sho...
The shift in the relationship between intrapericardial fluid pressure and volume induced by acute left ventricular pressure overload during cardiac tamponade.
Authors: T LCogswell, G ABernath, M HKeelan, L SWann, H SKlopfenstein
Journal: Circulation (1986)

We hypothesized that a process leading to an acute increase in cardiac size would change the relationship between intrapericardial pressure and fluid volume during cardiac tamponade, resulting in a change in the time of onset of right ventricular diastolic collapse (RVDC) as seen on the two-dimensional echocardiogram. Five spontaneously breathing dogs were instrumented to measure ascending aortic and right atrial blood pressures and intrapericardial pressure (IPP). A hydraulic occluder was placed around the proximal descending thoracic aorta. Each animal underwent six consecutive episodes of cardiac tamponade, three in the presence alternating with three in the absence of aortic constriction. The onset of RVDC was recorded and the volume infused into the pericardial space was measured. In the presence of aortic constriction, the relationship between pericardial pressure and incremental pericardial fluid volume was shifted so that IPP was an average of 3.4 mm Hg higher at any given intrapericardial fluid v...
SARS-CoV-2 antibodies and utility of point of care testing in Health Care Workers from a spanish University Hospital in Madrid
Authors: Mario Rodríguez-Domínguez, Beatriz Romero-Hernández, Daniel Marcos-Mencía, Marina Fernandez-Escribano, Montserrat Ferré-Masferrer, Juan Carlos Galán, Rafael Cantón
Journal: Clinical Microbiology and Infection (2021)
Intermittent ST depression and mortality after myocardial infarction.
Authors: WRuberman, RCrow, C RRosenberg, P MRautaharju, R EShore, B SPasternack
Journal: Circulation (1992)

BACKGROUNDWe conducted a case-control analysis to determine the contribution made to mortality by intermittent ST depression (STD) among patients enrolled in the already completed Beta Blocker Heart Attack Trial.METHODS AND RESULTSSTD was determined by computer analysis of 24-hour ECG tapes as a change in ST level by +/- 0.1 mV or more from the median value of ST of all normally conducted complexes for greater than or equal to 1 minute. All computer-detected ST events were verified by trained readers. To estimate risk of dying associated with STD, 261 deaths were compared with controls matched for age, sex, drug status, and time elapsed since acute myocardial infarction. In a model including relevant covariates, STD had a relative risk (RR) of 1.73 (95% confidence interval, 1.09-2.73). The RR was 2.56 (1.39-4.71) in untreated patients and 0.98 (0.48-2.00) in propranolol-treated patients. A history of angina, although not independently significant, was found to enhance these RRs. A gradient of risk was sho...
Vascular exchange in the kidney. Regional characterization by multiple indicator tomography.
Authors: C JLumsden, MSilverman, AZielinski, D GPotts, IShafik, A SBrody, C IWhiteside, MViolante
Journal: Circulation Research (1993)

In previous work with the method of multiple indicator dilution (MID), we have established that a spatially distributed model of transcapillary exchange proposed by Goresky, Ziegler, and Bach (GZB) accurately describes, at the in vivo whole-organ level, the handling of extracellular indicators in the canine renal cortex. To date, however, it has not been possible to assess the key hypothesis that GZB corresponds to the actual local mechanism of exchange in vivo and is not just a compact summary of the kidney's average whole-organ behavior. By adapting the MID method to high speed computed tomography (CT), we are now able to report that the GZB mechanism is an accurate description of renal cortical transcapillary exchange down to volumes of cortical tissue comprising no more than a few per cent of the total cortical mass, i.e., containing no more than a few thousand nephrons. A small bolus of iohexol (radiopaque extracellular indicator) or iodipamide ethyl ester microparticles (radiopaque plasma indicator)...
Cardiac Outcomes After Treatment for Depression in Patients With Acute Coronary Syndrome
Authors: George Rust
Journal: JAMA (2018)

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
Molecular cloning of human prostacyclin receptor cDNA and its gene expression in the cardiovascular system.
Authors: ONakagawa, ITanaka, TUsui, MHarada, YSasaki, HItoh, TYoshimasa, TNamba, SNarumiya, KNakao
Journal: Circulation (1994)

BACKGROUNDProstacyclin elicits a potent vasodilation and inhibition of platelet aggregation through binding to its membrane receptor. The impairment of prostacyclin receptor activity is implicated in various human cardiovascular diseases. In the present study, we succeeded in the isolation and characterization of human prostacyclin receptor cDNA and elucidated its gene expression in human tissues.METHODS AND RESULTSWe isolated a cDNA clone encoding the human prostacyclin receptor from a human lung cDNA library. The isolated cDNA clone encodes a 386-amino acid protein with seven putative transmembrane domains, which belongs to the G protein-coupled receptor superfamily. [3H]iloprost, a prostacyclin receptor agonist, specifically bound to the receptor transiently expressed in COS-7 cells. The binding was inhibited in the rank order of iloprost = cicaprost, another prostacyclin receptor agonist, > prostaglandin E1 (PGE1) > PGE2, PGF2 alpha, PGD2, STA2. In addition, iloprost dose-dependently stimulated cAMP g...
Atenolol: once-daily cardioselective beta blockade for angina pectoris.
Authors: GJackson, JSchwartz, R EKates, MWinchester, D CHarrison
Journal: Circulation (1980)

The physiology, pharmacokinetics and efficacy of atenolol, a cardioselective beta-adrenergic blocking agent, were evaluated in 10 patients with stable angina pectoris in a single-blind, dose-ranging study. After a 1-month control placebo period, atenolol was administered once daily at dosages of 25, 50, 100 and 200 mg for 2-week periods. All patients had fewer anginal attacks and consumed fewer nitroglycerin tablets than mg for 2-week periods. All patients had fewer anginal attacks and consumed fewer nitroglycerin tablets than during the placebo period. Twenty-four-hour ambulatory ECG recordings showed a decrease in mean hourly heart rate throughout the dosing period, with preservation of diurnal variation. Maximal, symptom-limited, treadmill exercise tests performed 3 hours after drug ingestion showed significantly increased exercise time and decreased double products for all doses, but especially with 100-mg and 200-mg doses. Exercise time 24 hours after drug ingestion continued to show a decrease in ma...
Contractures and increase in internal longitudianl resistance of cow ventricular muscle induced by hypoxia.
Authors: JWojtczak
Journal: Circulation Research (1979)

This study was performed to determine whether hypoxia in glucose-free solutions can increase the electrical resistance of intercellular junctions in ventricular muscle. Internal longitudinal resistance (Ri), mechanical tension, and transmembrane action potentials were measured simultaneously in cow ventricular trabeculae. The mean control value of Ri was 265 +/- 38 omegacm (mean +/- SE) at 34 degrees C. After 1 hour of hypoxia in glucose-free Tyrode's solution, it had increased by 300 +/- 41% (n = 11, P less than 0.001). The rise in Ri was closely related to the increase in resting tension (contracture). These effects were more pronounced during a second exposure to hypoxia and were potentiated by application of epinephrine, by increasing extracellular calcium concentration, and by increasing frequency of stimulation. Addition of glucose (50 mM) provided some protection against hypoxia. It is inferred that the increase in Ri is entirely due to the increase in the resistance of intercellular junctions (ele...
Recommendations for accurate genotyping of SARS-CoV-2 using amplicon-based sequencing of clinical samples
Authors: Slawomir Kubik, Ana Claudia Marques, Xiaobin Xing, Janine Silvery, Claire Bertelli, Flavio De Maio, Spyros Pournaras, Tom Burr, Yannis Duffourd, Helena Siemens, Chakib Alloui, Lin Song, Yvan Wenger, Alexandra Saitta, Morgane Macheret, Ewan W. Smith, Philippe Menu, Marion Brayer, Lars M. Steinmetz, Ali Si-Mohammed, Josiane Chuisseu, Richard Stevens, Pantelis Constantoulakis, Michela Sali, Gilbert Greub, Carsten Tiemann, Vicent Pelechano, Adrian Willig, Zhenyu Xu
Journal: Clinical Microbiology and Infection (2021)

Genotyping of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been instrumental in monitoring viral evolution and transmission during the pandemic. The quality of the sequence data obtained from these genotyping efforts depends on several factors, including the quantity/integrity of the input material, the technology, and laboratory-specific implementation. The current lack of guidelines for SARS-CoV-2 genotyping leads to inclusion of error-containing genome sequences in genomic epidemiology studies. We aimed to establish clear and broadly applicable recommendations for reliable virus genotyping.
Sarcoplasmic reticulum Ca2+ uptake and thapsigargin sensitivity in permeabilized rabbit and rat ventricular myocytes.
Authors: LHove-Madsen, D MBers
Journal: Circulation Research (1993)

Ca2+ uptake by the sarcoplasmic reticulum (SR) and free [Ca2+] were measured simultaneously with indo 1 and a Ca(2+)-selective minielectrode in suspensions of permeabilized rabbit or rat ventricular myocytes (approximately 10 mg/mL protein). In the presence of 25 mumol/L ruthenium red and 10 mmol/L oxalate, the Km for Ca2+ uptake by the SR was approximately 250 nmol/L in rabbit and rat ventricular myocytes. The maximal Ca2+ uptake rate was 2.4 times higher in rat than in rabbit. Addition of 5 nmol thapsigargin (TG) per milligram cell protein abolished Ca2+ uptake completely in both species. The [TG] necessary for a half-maximal reduction of the uptake rate (K1/2) was 55 pmol/mg cell protein for rabbit and 390 pmol/mg cell protein for rat. Assuming that the number of pump sites is two times the concentration of TG necessary to inhibit half of the Ca2+ pump activity (ie, the TG affinity is very high), the density of pump sites is 7.7 mumol/kg wet wt for rabbit and 54.6 mumol/kg wet wt for rat. Despite a fiv...
CC-Clear (Colon Capsule Cleansing Assessment And Report): The Novel Scale to Evaluate the Quality of Bowel Preparation in Capsule Colonoscopy – a Prospective Validation Study
Authors: R de Sousa Magalhães, B Sousa-Pinto, P Boal Carvalho, B Rosa, MJ Moreira, J Cotter
Journal: Endoscopy (2021)

Aims: CC-CLEAR ( C olon C apsule CLE ansing A ssessment and R eport) is a novel quantitative bowel preparation scale for CC, recently developed by our department, that displays excellent interobserver and intraobserver agreement rates when compared to other current used scales.
Telemedicine in Heart Failure—Ineffective or Just Ill Used?
Authors: Claudio Pedone, Raffaele Antonelli Incalzi
Journal: JAMA Internal Medicine (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 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
Nonlinear summation of depressor effects of carotid sinus pressure changes and aortic nerve stimulation in the rabbit.
Authors: NIshikawa, KSagawa
Journal: Circulation Research (1983)

We studied the interaction between the carotid sinus and aortic arch baroreflexes' control of arterial pressure in 13 rabbits anesthetized with urethane. The carotid sinus baroreceptor region was isolated to control carotid sinus pressure. The aortic nerve was transected cervically and stimulated with 4-V electrical pulses at 5 Hz and 0.5-msec duration, which caused a 20-30 mm Hg decrease in arterial pressure. Several protocols were used to analyze the interaction. In the first, we compared the combined effect of the stimulation of a unilateral aortic nerve and a simultaneous increase of bilateral carotid sinus pressures from 40 to 70-80 mm Hg to the sum of these effects measured separately. The combined effect was always larger than the sum of the separate effects. In the second protocol, we varied carotid sinus pressures between 40 and 140 mm Hg and, at each carotid sinus pressure, measured the decrease in arterial pressure caused by unilateral aortic nerve stimulation. The fall in arterial pressure was...
A method for determining segmental resistances in the microcirculation from pressure-flow measurements.
Authors: S HNellis, B WZweifach
Journal: Circulation Research (1977)

On the basis of an electrical analog, open circuit impedance functions were used to analyze the microcirculation. No specific structure need be assumed except a two-port, two-terminal network in which the major artery and vein supplying the tissue represent the input port and the two ends of the microvessel under study are the output port. The open circuit measurements were made by occluding microvessels in the exteriorized omentum of anesthetized rabbits. The pressure upstream and downstream to the occlusion defines the source pressure of a Thevenin's equivalent circuit. The equivalent resistance value was calculated by plotting the flow through a given microvessel against the pressure developed during a gradual occlusion. The changes in pressure vs. the changes in flow during a progressive occlusion were found to be linearly related. The Thevenin's equivalent resistance was maximum downstream to an occluded artery and upstream to the occluded vein. Within the capillary network, source pressures consiste...
Beta 1-adrenoceptor stimulation and beta 2-adrenoceptor stimulation differ in their effects on contraction, cytosolic Ca2+, and Ca2+ current in single rat ventricular cells.
Authors: R PXiao, E GLakatta
Journal: Circulation Research (1993)

The effects of beta 2- and beta 1-adrenoceptor (beta 2AR and beta 1AR, respectively) agonists on the cytosolic Ca2+ (Cai) transient (indexed by the transient increase in indo-1 fluorescence ratio after excitation), twitch amplitude (measured via photodiode array), membrane potential, and L-type sarcolemmal Ca2+ current (ICa, measured by whole-cell patch electrode) were assessed in single rat ventricular myocytes. The selective beta 2AR agonist Zinterol increased the amplitudes of both the Cai transient and twitch in a concentration-dependent manner. Similar results were obtained when beta 2ARs were stimulated with isoproterenol in the presence of the selective beta 1AR antagonist CGP 20712A. beta 1AR stimulation induced by norepinephrine increased twitch amplitude to about the same extent as did beta 2AR stimulation. However, several striking differences between response to beta 1AR and beta 2AR stimulation were observed. beta 1AR stimulation had the potent effect of abbreviating the time course of the co...
Effect of oral propranolol on rest, exercise and postexercise left ventricular performance in normal subjects and patients with coronary artery disease.
Authors: R CMarshall, GWisenberg, H RSchelbert, EHenze
Journal: Circulation (1981)

The effect of beta-adrenergic blockade with oral propranolol on resting, exercise and postexercise ventricular performance was evaluated using multiple-gated equilibrium cardiac blood and pool images in normal volunteers and patients with coronary artery disease. Propranolol produced no detectable effect on basal left ventricular function in normal subjects at doses producing intermediate (160 mg propranolol/day) and maximal (434 +/- 99 mg propranolol/day) beta blockade and in patients with coronary artery disease at clinically effective antianginal doses (162 +/- 47 mg propranolol/day). During exercise, a dose-related, negative inotropic effect was observed in normal subjects: 160 mg propranolol/day produced a small but statistically insignificant decline in exercise left ventricular performance, whereas maximal beta blockade significantly depressed the left ventricular response to exercise. In patients with coronary artery disease, propranolol's effect on exercise ventricular performance depended on the...