tbuckley/cabot-search huggingface dataset:
Ultrasonic energy. Effects on vascular function and integrity.
Authors: T AFischell, M AAbbas, G WGrant, R JSiegel
Journal: Circulation (1991)

BACKGROUNDUltrasonic energy transmitted via flexible wire probes provides a new means of ablating atherosclerotic plaque. We studied the effects of ultrasonic energy (20 kHz) delivered via a ball-tipped wire probe on arterial vasomotor behavior in rabbit thoracic aortas in a perfused whole-vessel model.METHODS AND RESULTSAfter precontraction with phenylephrine (10(-5) M) or KCl (60 mM), the effects of ultrasonic energy (0.7-5.5 W x 60 seconds, 42-330 J) on arterial vasomotor behavior were measured using long-axis ultrasonic vessel imaging of the proximal (ultrasonic probe-treated) and distal (untreated) control segments. The efficacy of plaque ablation at these same probe-tip power outputs was evaluated in atherosclerotic, human cadaver iliofemoral arteries. Ultrasonic energy caused dose (energy)-dependent relaxation in rabbit aortas after precontraction with phenylephrine in arteries with endothelium (n = 8) and without endothelium (n = 8) (p less than 0.001 versus ultrasound treated at power outputs of ...
Ambulatory follow-up of aortic dissection by transesophageal two-dimensional and color-coded Doppler echocardiography.
Authors: SMohr-Kahaly, RErbel, HRennollet, NWittlich, MDrexler, HOelert, JMeyer
Journal: Circulation (1989)

Follow-up of 18 patients with aortic dissection (five with type I, one with type II, 11 with type III dissection according to DeBakey) by transesophageal, two-dimensional and color-coded Doppler echocardiography showed a persistence of the false lumen in five of seven patients (71%) after surgery and in nine of 11 patients (82%) after medical therapy. In two patients treated with surgery, the dissected part of the aorta had been resected, whereas in two patients treated medically, a progressive and complete obliteration of the false lumen was observed. In the false lumen, thrombus formation was absent in four, localized in four, and progressive in six patients. Flow within the false lumen could be registered in 14 patients, and two distinct flow patterns were differentiated (laminar biphasic flow or slowly circulating flow). Persisting intimal tears were visualized by two-dimensional echocardiography in four patients, whereas color-coded Doppler showed an additional one to three intimal tears in the desce...
Discontinuation of Antihypertensive Treatment in Elderly Patients and Cognitive Function—Reply
Authors: Jessica C. Foster-Dingley, Justine E. F. Moonen, Roos C. van der Mast
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
Augmentation of coronary blood flow by intra-aortic balloon pumping in patients after coronary angioplasty.
Authors: M JKern, FAguirre, RBach, TDonohue, RSiegel, JSegal
Journal: Circulation (1993)

BACKGROUNDControversy exists regarding the ability of intra-aortic balloon pumping to increase coronary blood flow in patients with obstructive coronary artery disease. To assess the effects of intra-aortic balloon pumping on coronary hemodynamics, we measured coronary blood flow velocity with a 0.018-in. Doppler-tipped angioplasty guide wire in 15 patients who received an intra-aortic balloon pump for typical clinical indications.METHODS AND RESULTSIntra-aortic balloon pumping augmented diastolic pressure 83 +/- 35%. In nine patients before angioplasty, peak diastolic coronary flow velocity beyond the stenosis (mean diameter narrowing, 95 +/- 7%) was 5.3 +/- 9.6 cm/sec and was unaffected by intra-aortic balloon pumping. After angioplasty, the improved coronary luminal diameter narrowing (n = 12; mean narrowing, 18 +/- 12%) was associated with increased distal diastolic flow velocity integral and peak diastolic and mean velocities (13.3 +/- 8.4 units: 36.4 +/- 18.3 and 24.0 +/- 11.4 cm/sec, respectively; ...
Increased TLR7 Signaling of BCR-Activated B Cells in Chronic Graft-Versus Host Disease (cGVHD)
Authors: Amy N. Suthers, Hsuan Su, Sarah M. Anand, Jonathan C Poe, Jeremy J. Rose, Frances T. Hakim, Steven Z. Pavletic, David A. Rizzieri, Mitchell E. Horwitz, Yiping Yang, Nelson J. Chao, Stefanie Sarantopoulos
Journal: Blood (2017)
Effects of acetylcholine on electrophysiological properties of rabbit cardiac Purkinje fibers.
Authors: KMubagwa, ECarmeliet
Journal: Circulation Research (1983)

The action of acetylcholine (10(-9)-10(-4) M) was investigated in isolated rabbit cardiac Purkinje fibers, using standard microelectrode recording of transmembrane potentials and two-microelectrode voltage clamp technique. In nonstimulated fibers, acetylcholine hyperpolarized the diastolic membrane potential and slowed or suppressed spontaneous activity. The hyperpolarization was more pronounced in low potassium solutions and in depolarized fibers; it was less marked in the presence of cesium (2 X 10(-2) M), and was suppressed by barium (3-5 X 10(-3) M). In stimulated fibers, acetylcholine shortened the action potential duration and shifted the plateau level to more negative values; this effect was influenced little by the stimulation frequency and not by chloride removal from the perfusing solution. In voltage-clamped preparations, acetylcholine shifted the holding current in the outward direction at potentials less negative than EK, while it shifted the current in the inward direction at potentials more...
A framework for microbiome science in public health
Authors: Jeremy E. Wilkinson, Eric A. Franzosa, Christine Everett, Chengchen Li, Sena Bae, Isa Berzansky, Amrisha Bhosle, Kjetil Bjørnevik, Caitlin A. Brennan, Y. Grace Cao, Eunyoung Chun, Slater L. Clay, Kathrin Fenn, A. Brantley Hall, Dylan Lennon, Lior Lobel, Siyuan Ma, Wenjie Ma, Sagun Maharjan, Lauren J. McIver, Samantha Molsberry, Geicho Nakatsu, Long H. Nguyen, Diogo Fonseca-Pereira, Madikay Senghore, Dmitry Shungin, Rebecca Stern, Kelsey N. Thompson, Tommi Vatanen, Aaron M. Walsh, Dong D. Wang, Kai Wang, Ya Wang, Yan Yan, Yancong Zhang, Alberto Ascherio, Rachel N. Carmody, Jorge E. Chavarro, Marios Giannakis, Smita Gopinath, Christopher D. Golden, Yonatan Grad, William P. Hanage, Albert Hofman, Kyu Ha Lee, Marc Lipsitch, Kimmie Ng, Shuji Ogino, Natalia Palacios, Qi Sun, Matthew K. Waldor, Frank B. Hu, Dyann F. Wirth, Mingyang Song, Andrew T. Chan, Eric Rimm, Wendy S. Garrett, Curtis Huttenhower
Journal: Nature Medicine (2021)
Joint testing of IgM and IgG has high value for ruling in SARS-CoV-2 infection
Authors: Mark Loeb
Journal: Annals of Internal Medicine (2021)

Source CitationGuo CC, Mi JQ, Nie H. Seropositivity rate and diagnostic accuracy of serological tests in 2019-nCoV cases: a pooled analysis of individual studies. Eur Rev Med Pharmacol Sci. 2020;24:10208-18. https://pubmed.ncbi.nlm.nih.gov/33090430/AbstractClinical Impact RatingsGIM/FP/GP: Emergency Med: Hospitalists: Infectious Disease: Public Health:
Oxypurinol limits myocardial stunning but does not reduce infarct size after reperfusion.
Authors: D WPuett, M BForman, C UCates, B HWilson, K RHande, G CFriesinger, RVirmani
Journal: Circulation (1987)

To explore the role of oxygen free radicals produced by the xanthine oxidase pathway on infarct size and left ventricular function, the effect of oxypurinol, an active metabolite of allopurinol and a potent noncompetitive inhibitor of xanthine oxidase, was assessed in a 90 min, closed-chest, canine preparation of occlusion-reperfusion. Animals were randomized to receive 25 mg/kg iv oxypurinol (n = 13) or saline (n = 13) 60 min after occlusion. Regional myocardial blood flow was measured with radioactive microspheres and regional ventricular function with contrast ventriculography. Hemodynamic variables, regional myocardial blood flow, and size of the occluded bed were similar in the two groups. Oxypurinol failed to reduce infarct size 24 hr after reperfusion when expressed as a percentage of the area at risk (36.3 +/- 4.9% vs 36.0 +/- 5.6%; p = NS). Both groups exhibited comparative radial shortening at baseline and similar degrees of dyskinesia 1 hr into occlusion (-6.6 +/- 1.2% vs -4.9 +/- 1.0%). Howeve...
Central nervous system mechanisms involved in inhibition of renal sympathetic nerve activity induced by arginine vasopressin.
Authors: SSuzuki, ATakeshita, TImaizumi, YHirooka, MYoshida, SAndo, MNakamura
Journal: Circulation Research (1989)

Previous studies have suggested that intravenous infusion of arginine vasopressin (AVP) inhibits sympathetic nerve activity (SNA) in rabbits by its action at the brainstem. This study aimed to determine, first, whether this action of AVP depended on functioning baroreflex mechanisms. The second aim was to determine the role of the nucleus tractus solitarii (NTS) in mediating this action of AVP. Experiments were performed in rabbits anesthetized with alpha-chloralose. Intravenous infusions of AVP (1, 3, and 10 mU/kg/min) resulted in progressive inhibition of renal SNA in rabbits with intact arterial baroreceptors and vagal afferents as well as in rabbits with sinoaortic denervation and bilateral vagotomy. The magnitudes of renal SNA inhibition evoked with AVP were comparable in the two groups. Renal SNA inhibition evoked with AVP at doses of 1 and 3 mU/kg/min in rabbits after sinoaortic denervation and vagotomy was totally blocked by chemical lesions with kainic acid of the bilateral NTS or the area postre...
107P Baseline total metabolic tumour volume on [18F]FDG PET/CT as promising biomarker in advanced NSCLC patients treated with first line pembrolizumab
Authors: F.G. Dall'Olio, D. Calabrò, N. Conci, G. Argalia, P. Marchese, F. Fabbri, B. Fragomeno, S. Fanti, V. Ambrosini, A. Ardizzoni
Journal: Journal of Thoracic Oncology (2021)
Coronary hemodynamics and myocardial metabolism of lactate, free fatty acids, glucose, and ketones in patients with septic shock.
Authors: J FDhainaut, M FHuyghebaert, J FMonsallier, GLefevre, JDall'Ava-Santucci, FBrunet, DVillemant, ACarli, DRaichvarg
Journal: Circulation (1987)

To investigate disturbances in the coronary circulation and myocardial metabolism during septic shock, we examined coronary sinus blood flow and myocardial substrate extraction in 40 patients with septic shock and 13 control patients. Patients with coronary artery disease were excluded from this study. The global hemodynamic pattern of the septic patients was characterized by a lower stroke volume, despite an elevated cardiac index. Coronary sinus blood flow was high (187 +/- 47 vs 130 +/- 21 ml/min in the control group, p less than .001) due to marked coronary vasodilation, especially in the subgroup of nonsurvivors. In contrast to the control group, myocardial lactate uptake was elevated, while that of free fatty acids, glucose, and ketone bodies was diminished in patients with septic shock. These findings were especially prominent in the nonsurvivors. Expressed as oxygen equivalents, the contribution of free fatty acids as an energy source of the myocardium was markedly diminished in septic patients (1...
Hay-Fever Treatment by Dunbar's Remedies (Pollantin).
Authors: F. S. Clarke
Journal: JAMA (1906)

LeMars, Iowa, Aug. 17, 1906. <h3>To the Editor:</h3> —I have been very much interested in the recital of the various physicians' experiences in the use of pollantin. This is the third season I have used the serum In treating my hay-fever patients, and my experience with it has been very gratifying. I do not recall a single patient that has not been benefited by its use, and some have told me that they have enjoyed comparative freedom from attacks by using the serum and powder fairly regularly throughout the season. I very much deprecate the container used for the medicine. It is a great nuisance for the physician to be obliged to remove all the advertising matter, etc., before dispensing the serum. Can not these people be induced to put the medicine out in some other form? It seems to me that those containers were made especially for display on
Reflex modulation of lymphatic pumping in sheep.
Authors: N GMcHale, T HAdair
Journal: Circulation Research (1989)

Lymphatic pumping activity was examined in halothane-anesthetized sheep. A doubly cannulated preparation of the mesenteric lymph duct was isolated from lymph input, other than that from a constant pressure reservoir of artificial lymph attached to its inflow cannula, but had its blood supply and innervation intact. A cerebral ischemic response, evoked by injection of 2 ml air into the common carotid artery, increased both mean arterial pressure and fluid propulsion by the lymphatic. The latter rose from a control value of 45 microliters/min to a peak of 74 microliters/min. When 10(-4) M phentolamine was introduced into the lymphatic lumen, there was a transient increase followed by a sustained fall in lymph pumping. Repetition of the air injection while phentolamine was present in the duct lumen produced no increase in lymph pumping. In adrenalectomized animals, resting lymph propulsion by the mesenteric duct was depressed, and the response to air injection was attenuated but remained significantly grea...
Electrophysiologic effects of lidocaine on sinus node and atrium in patients with and without sinoatrial dysfunction.
Authors: R CDhingra, P CDeedwania, J MCummings, FAmat-Y-Leon, DWu, PDenes, K MRosen
Journal: Circulation (1978)

Electrophysiological studies were conducted in 13 patients with normal sinus node function and 14 with sinus node dysfunction before and after intravenous lidocaine. Mean +/- SEM sinus cycle length significantly shortened from 810 +/- 34.3 to 774 +/- 34.3 msec in patients with normal sinus node (P less than 0.001) and from 1061 +/- 67.6 to 1016 +/- 64.5 msec in patients with sinus node dysfunction (P less than 0.025) after lidocaine. Mean sinus recovery time was 1027 +/- 49.4 before and 1026 +/- 52.5 msec after lidocaine in patients with normal sinus node (NS) and 1269 +/- 97.7 before and 1170 +/- 73.8 msec after lidocaine in patients with sinus node dysfunction (P less than 0.05). Mean calculated sinoatrial conduction time was 87 +/- 9.5 before and 90 +/- 9.2 msec after lidocaine in patients with normal sinus node (NS) and 80 +/- 10.3 before and 96 +/- 10.2 msec after lidocaine in patients with sinus node dysfunction (P less than 0.001). Mean atrial effective and functional refractory periods were not si...
Bystander cardiopulmonary resuscitation. Is ventilation necessary
Authors: R ABerg, K BKern, A BSanders, C WOtto, R WHilwig, G AEwy
Journal: Circulation (1993)

BACKGROUNDPrompt initiation of bystander cardiopulmonary resuscitation (CPR) improves survival. Basic life support with mouth-to-mouth ventilation and chest compressions is intimidating, difficult to remember, and difficult to perform. Chest compressions alone can be easily taught, easily remembered, easily performed, adequately taught by dispatcher-delivered telephone instruction, and more readily accepted by the public. The principal objective of this study was to evaluate the need for ventilation during CPR in a clinically relevant swine model of prehospital witnessed cardiac arrest.METHODS AND RESULTSThirty seconds after ventricular fibrillation, swine were randomly assigned to 12 minutes of chest compressions plus mechanical ventilation (group A), chest compressions only (group B), or no CPR (group C). Standard advanced cardiac life support was then provided. Animals successfully resuscitated were supported for 2 hours in an intensive care setting, and then observed for 24 hours. All 16 swine in grou...
Impaired early left ventricular relaxation in coronary artery disease: effects of intracornary nifedipine.
Authors: M FRousseau, CVeriter, J MDetry, LBrasseur, HPouleur
Journal: Circulation (1980)

It has been shown that the maximal rate of left ventricular (LV) relaxation is impaired in patients with coronary artery disease (CAD) under basal conditions. To test the hypothesis that this impaired LV relaxation could be related to viable but metabolically abnormal myocardium, we studied the time course of isovolumic LV pressure fall in 21 patients with CAD and in 13 control subjects under basal conditions. This study was repeated after intracoronary injection of the calcium antagonist nifedipine (N) in 11 patients with CAD and in eight controls. Our data showed that isovolumic pressure fall was biexponential in 20 of 21 CAD patients and in six of 13 controls. Moreover, the time constant of isovolumic pressure fall during the first 40 msec after peak (negative) dP/dt (T1) was significantly greater in CAD patients than in controls (62 +/- 3 vs 44 +/- 1 msec, p < 0.002); the time constant of pressure fall during the 40-80 msec after peak (negative) dP/dt (T2) was similar in both groups ( 42 +/- 2 vs 39 +...
Morphometry of canine coronary arteries, arterioles, and capillaries during hypertension and left ventricular hypertrophy.
Authors: R JTomanek, P JPalmer, G LPeiffer, K LSchreiber, C LEastham, M LMarcus
Journal: Circulation Research (1986)

The mechanisms responsible for the increase in minimal coronary vascular resistance per unit mass of myocardium in animals with chronic hypertension and left ventricular hypertrophy remain unidentified. Because increases in wall thickness of resistance vessels in some vascular beds in response to hypertension may decrease luminal diameter, we hypothesized that similar changes may occur in the coronary vasculature. To test this hypothesis, we performed hemodynamic and morphometric studies on eight dogs with renovascular hypertension (one kidney, one clip) of 6 weeks' duration, and in six normotensive dogs. Hypertension evoked a 27% increase in left ventricular mass and was associated with a 67% increase in left ventricular minimal coronary vascular resistance per 100 g calculated from coronary perfusion measured with microspheres during adenosine infusion. The vasculature was fixed via perfusion of glutaraldehyde and tissue samples from the left ventricle were embedded in Epon. Wall:lumen ratios, determine...
Hypertension, a Moving Target in COVID-19
Authors: Carmine Savoia, Massimo Volpe, Reinhold Kreutz
Journal: Circulation Research (2021)

Coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) associates with a considerable high rate of mortality and represents currently the most important concern in global health. The risk of more severe clinical manifestation of COVID-19 is higher in males and steeply raised with age but also increased by the presence of chronic comorbidities. Among the latter, early reports suggested that arterial hypertension associates with higher susceptibility to SARS-CoV-2 infection, more severe course and increased COVID-19-related deaths. Furthermore, experimental studies suggested that key pathophysiological hypertension mechanisms, such as activation of the renin-angiotensin system (RAS), may play a role in COVID-19. In fact, ACE2 (angiotensin-converting-enzyme 2) is the pivotal receptor for SARS-CoV-2 to enter host cells and provides thus a link between COVID-19 and RAS. It was thus anticipated that drugs modulating the RAS including an upregulation of ACE2 may increase the risk for infection with SARS-CoV-2 and poorer outcomes in COVID-19. Since the use of RAS-blockers, ACE inhibitors or angiotensin receptor blockers, represents the backbone of recommended antihypertensive therapy and intense debate about their use in the COVID-19 pandemic has developed. Currently, a direct role of hypertension, independent of age and other comorbidities, as a risk factor for the SARS-COV-2 infection and COVID-19 outcome, particularly death, has not been established. Similarly, both current experimental and clinical studies do not support an unfavorable effect of RAS-blockers or other classes of first line blood pressure lowering drugs in COVID-19. Here, we review available data on the role of hypertension and its management on COVID-19. Conversely, some aspects as to how the COVID-19 affects hypertension management and impacts on future developments are also briefly discussed. COVID-19 has and continues to proof the critical importance of hypertension research to address questions that are important for global health.
Effects of anoxia on kinetics of [13N] glutamate and 13NH3 metabolism in rabbit myocardium.
Authors: JKrivokapich, R EKeen, M EPhelps, K IShine, J RBarrio
Journal: Circulation Research (1987)

Positron emission tomography is a unique noninvasive imaging technique that provides cross-sectional images of radiotracer concentrations in myocardium and permits measurement of blood flow as well as metabolism. Ammonia and glutamate have been labeled with the positron-emitter 13N (half-life 10 minutes) for use with positron emission tomography as tracers of flow and metabolism, respectively. In order to characterize the fate of these 13N-labelled compounds in myocardium, isolated rabbit interventricular septa were used to study the kinetics of [13N] glutamate ([13N]glu) and 13NH3 under aerobic and anoxic conditions. Tissue analyses 6 minutes after injection of a [13N]glu bolus into myocardium revealed that 70% of the 13N-label was present in [13N]glu 12%, 11%, and 4% in [13N]alanine ([13N]ala), [13N]aspartate ([13N]asp), and [13N]glutamine ([13N]gln), respectively. The corresponding relative specific activities were 1.0:0.4:0.5:0.01. Anoxia resulted in a significant increase in [13N]ala with a reduction...
Slow recovery of excitability and the Wenckebach phenomenon in the single guinea pig ventricular myocyte.
Authors: MDelmar, D CMichaels, JJalife
Journal: Circulation Research (1989)

The cellular mechanisms of Wenckebach periodicity were investigated in single, enzymatically dissociated guinea pig ventricular myocytes, as well as in computer reconstructions of transmembrane potential of the ventricular cell. When depolarizing current pulses of the appropriate magnitude were delivered repetitively to a well-polarized myocyte, rate-dependent activation failure was observed. Such behavior accurately mimicked the Wenckebach phenomenon in cardiac activation and was the consequence of variations in cell excitability during the diastolic phase of the cardiac cycle. The recovery of cell excitability during diastole was studied through the application of single test pulses of fixed amplitude and duration at variable delays with respect to a basic train of normal action potentials. The results show that recovery of excitability is a slow process that can greatly outlast action potential duration (i.e., postrepolarization refractoriness). Two distinct types of subthreshold responses were recorde...