tbuckley/cabot-search huggingface dataset:
Inaccuracy of mitral pressure half-time immediately after percutaneous mitral valvotomy. Dependence on transmitral gradient and left atrial and ventricular compliance.
Authors: J DThomas, G TWilkins, C YChoong, V MAbascal, I FPalacios, P CBlock, A EWeyman
Journal: Circulation (1988)

Mitral pressure half-time (T1/2) is widely used as an independent measure of mitral valve area in patients undergoing percutaneous mitral valvotomy. However, fluid dynamics theory predicts T1/2 to be strongly dependent on chamber compliance and the peak transmitral gradient, which are variables that change dramatically with valvotomy. These theoretical predictions were tested in an in vitro model of the left heart where valve area, chamber compliance, and initial gradient were independently adjusted. Measured T1/2 was observed to vary inversely with orifice area and directly with net chamber compliance and the square root of the initial pressure gradient. Theoretical predictions of T1/2 agreed with observed values with r = 0.998. To test this theory in vivo, the hemodynamic tracings of 18 patients undergoing mitral valvotomy were reviewed. Predictions were made for T1/2 assuming dependence only on valve area; these showed some correlations before valvotomy (r = 0.48-0.64, p less than 0.05) but none after ...
EUS Versus MRCP for Patients With Intermediate Likelihood of Choledocholithiasis: A Randomized Controlled Trial
Authors: N Jagtap, JK Kumar, S Lakhtakia, R Kalapala, SF Memon, M Ramchandani, J Basha, M Tandan, R Gupta, Z Nabi, R Chavan, R Yerlagadda, Reddy DN
Journal: Endoscopy (2021)

Aims In patients with an intermediate likelihood group of choledocholithiasis, ESGE guidelines recommend either EUS or MRCP to diagnose choledocholithiasis. There is no randomized control trial conducted to compare EUS and MRCP for diagnosing choledocholithiasis in these patients. We aimed to compare EUS and MRCP for the diagnosis of choledocholithiasis in patients with the intermediate likelihood of choledocholithiasis.
Levodopa-Induced Dyskinesia in Parkinson Disease Specifically Associates With Dopaminergic Depletion in Sensorimotor-Related Functional Subregions of the Striatum
Authors: Miguel A. Labrador-Espinosa, Michel J. Grothe, Daniel Macías-García, Silvia Jesús, Astrid Adarmes-Gómez, Laura Muñoz-Delgado, Paula Fernández-Rodríguez, Juan Francisco Martín-Rodríguez, Ismael Huertas, David García-Solís, Pablo Mir
Journal: Clinical Nuclear Medicine (2021)

Purpose To determine whether the development of levodopa-induced dyskinesia (LID) in Parkinson disease (PD) specifically relates to dopaminergic depletion in sensorimotor-related subregions of the striatum. Methods Our primary study sample consisted of 185 locally recruited PD patients, of which 73 (40%) developed LID. Retrospective 123 I-FP-CIT SPECT data were used to quantify the specific dopamine transporter (DAT) binding ratio within distinct functionally defined striatal subregions related to limbic, executive, and sensorimotor systems. Regional DAT levels were contrasted between patients who developed LID (PD + LID) and those who did not (PD-LID) using analysis of covariance models controlled for demographic and clinical features. For validation of the findings and assessment of the evolution of LID-associated DAT changes from an early disease stage, we also studied serial 123 I-FP-CIT SPECT data from 343 de novo PD patients enrolled in the Parkinson Progression Marker’s Initiative using mixed linear model analysis. Results Compared with PD-LID, DAT level reductions in PD + LID patients were most pronounced in the sensorimotor striatal subregion ( F = 5.99, P = 0.016) and also significant in the executive-related subregion ( F = 5.30, P = 0.023). In the Parkinson Progression Marker’s Initiative cohort, DAT levels in PD + LID (n = 161, 47%) were only significantly reduced compared with PD-LID in the sensorimotor striatal subregion ( t = −2.05, P = 0.041), and this difference was already present at baseline and remained largely constant over time. Conclusion Measuring DAT depletion in functionally defined sensorimotor-related striatal regions of interest may provide a more sensitive tool to detect LID-associated dopaminergic changes at an early disease stage and could improve individual prognosis of this common clinical complication in PD.
Endothelium-dependent inhibition of ergonovine-induced contraction is impaired in porcine coronary arteries with regenerated endothelium.
Authors: HShimokawa, N AFlavahan, J TShepherd, P MVanhoutte
Journal: Circulation (1989)

The inhibitory effects of the endothelium against ergonovine-induced contraction were examined in isolated porcine coronary arteries under normal conditions and after endothelial regeneration. Endothelium-dependent responses were examined in vitro in normal Yorkshire pigs (n = 16) and in pigs that had undergone balloon endothelium removal of the left anterior descending coronary artery (LAD) 4 weeks before the study (n = 10). The presence of a complete endothelial lining was confirmed histologically. In rings from normal arteries contracted with prostaglandin F2 alpha in the presence of indomethacin and ketanserin (a 5-HT2-serotonergic blocker), ergonovine caused endothelium-dependent relaxations. They were attenuated by rauwolscine (an alpha 2-adrenergic blocker), inhibited by methiothepin (a combined 5-HT1- and 5-HT2-serotonergic blocker) or by pertussis toxin (an inhibitor of several G proteins) and abolished by oxyhemoglobin (a selective inactivator of endothelium-derived relaxing factor). In quiescen...
Noninvasive Carotid Artery Testing
Authors: George Howard
Journal: Annals of Internal Medicine (1995)

Letters15 October 1995Noninvasive Carotid Artery TestingGeorge Howard, DrPH and James F. Toole, MDGeorge Howard, DrPHBowman Gray School of Medicine; Winston-Salem, NC 27157Search for more papers by this author and James F. Toole, MDBowman Gray School of Medicine; Winston-Salem, NC 27157Search for more papers by this authorAuthor, Article, and Disclosure Informationhttps://doi.org/10.7326/0003-4819-123-8-199510150-00014 SectionsAboutFull TextPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissions ShareFacebookTwitterLinkedInRedditEmail TO THE EDITOR:The importance of noninvasive testing of the carotid arteries continues to increase with the recent reports of the Asymptomatic Carotid Atherosclerosis Study (ACAS) [1] and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) [2]. The meta-analysis by Blakeley and colleagues [3] contrasting the sensitivity and specificity of noninvasive techniques provides information needed by clinicians in their evaluations of patient populations.Unfortunately, the brief mention of “publication bias” as a shortcoming of this report may lead clinician-readers to underestimate this problem. Because laboratories finding a poor correlation between noninvasive evaluations and arteriography are unlikely to publish their results, ...References1. “Endarterectomy for asymptomatic carotid artery stenosis. Executive Committee for the Asymptomatic Carotid Atherosclerosis Study. JAMA. 1995; 273:1421-8.” Google Scholar2. “North American Symptomatic Carotid Endarterectomy Trial Collaborators. Beneficial effect of carotid endarterectomy in symptomatic patients with high-grade stenosis. N Engl J Med. 1991; 325:445-53.” Google Scholar3. Blakeley DD, Oddone EZ, Hasselblad V, Simel DL, Matchar DB. Noninvasive carotid artery testing. A meta-analytic review. Ann Intern Med. 1995; 122:360-7. Google Scholar4. Howard G, Chambless LE, Baker WH, Ricotta JJ, Jones AM, O'Leary D, et al. A multicenter validation study of Doppler ultrasound versus angiography. J Stroke Cerebrovas Dis. 1991; 1:166-73. Google Scholar Author, Article, and Disclosure InformationAuthors: George Howard, DrPH; James F. Toole, MDAffiliations: Bowman Gray School of Medicine; Winston-Salem, NC 27157 PreviousarticleNextarticle Advertisement FiguresReferencesRelatedDetails Metrics 15 October 1995Volume 123, Issue 8Page: 633KeywordsAngiographyCarotid arteriesCarotid endarterectomyExercisePatient Protection and Affordable Care ActPopulation statisticsPositive predictive valueQuality improvementSpecificityUltrasound imaging ePublished: 15 August 2000 Issue Published: 15 October 1995 Copyright & PermissionsCopyright © 1995 by American College of Physicians. All Rights Reserved.PDF downloadLoading ...
Impact Of The Covid-19 Pandemic In The Gastroenterology Department – The Gastroenterologists’ Perspective Nationwide And The Real Impact In A Portuguese Center
Authors: C Gomes, R Pinho, Silva JC, E Afecto, J Correia, J Carvalho
Journal: Endoscopy (2021)

Aims Several Gastroenterology Societies created recommendations in order to reduce any non-essential exposure to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus. The purposes of this paper are 1) to evaluate the national gastroenterologists' perspective of the impact of COVID-19 and 2) to evaluate the impact of the reorganization of the Gastroenterology department of Centro Hospitalar Vila Nova de Gaia/Espinho (CHVNG/E) during COVID-19 Pandemic.
Improvement in indexes of diastolic performance in patients with congestive heart failure treated with milrinone.
Authors: E SMonrad, R GMcKay, D SBaim, W SColucci, M AFifer, G VHeller, H DRoyal, WGrossman
Journal: Circulation (1984)

To elucidate the mechanisms by which the new bipyridine inotropic agent milrinone improves cardiac function, we examined multiple indexes of left ventricular diastolic function before and after administration of milrinone to patients with advanced (NYHA class III or IV) congestive heart failure. In 13 patients left ventricular pressure measurements were made with a micromanometer to permit assessment of peak negative dP/dt and the time constant of left ventricular isovolumic relaxation, T, before and after milrinone. In nine patients radionuclide ventriculographic studies were performed during left heart catheterization, allowing calculation of left ventricular peak filling rate, volumes, and the diastolic pressure-volume relationship before and after milrinone. After intravenous administration of milrinone, peak negative dP/dt increased (+ 18%; p less than .01) and T decreased (-30%; p less than .01), while heart rate increased by only 8% (87 +/- 12 to 94 +/- 15 beats/min; p less than .01), left ventricu...
95TiP DUART: A phase II study of durvalumab following radiotherapy in patients with unresectable, stage III NSCLC ineligible for chemotherapy
Authors: A.R. Filippi, R. Dziadziuszko, M.R. Garcia Campelo, J-B. Paoli, W. Sawyer, I.E. Díaz Pérez
Journal: Journal of Thoracic Oncology (2021)
Comparative effects of propranolol and verapamil alone and in combination on left ventricular function and volumes in patients with chronic exertional angina: a double-blind, placebo-controlled, randomized, crossover study with radionuclide ventriculography.
Authors: D LJohnston, V AGebhardt, ADonald, W JKostuk
Journal: Circulation (1983)

With the use of equilibrium radionuclide ventriculography the effects on left ventricular (LV) function of 160 mg oral propranolol daily and 360 mg verapamil daily alone and in combination were compared in 18 patients with chronic exertional angina. A randomized, double-blind, placebo-controlled, crossover protocol was used. The reduction in exercise rate-pressure product induced by the combination (118 +/- 28 mm Hg/min) was significantly greater (p less than .05) than that by propranolol (135 +/- 27 mm Hg/min) or verapamil alone (163 +/- 28 mm Hg/min). In patients at rest, neither single nor combined therapy altered global or regional left ventricular ejection fractions (EFs). Verapamil, but not propranolol, increased (p less than .05) cardiac volumes of resting subjects; used in combination, no further increase in LV volume occurred. With placebo, exercise global EF did not decrease from the level at rest and therefore no drug effect could be demonstrated for this parameter of LV function. By an evaluat...
Effects on the rabbit coronary artery of LP-805, a new type of releaser of endothelium-derived relaxing factor and a K+ channel opener.
Authors: MNakashima, TAkata, HKuriyama
Journal: Circulation Research (1992)

In the rabbit epicardial coronary artery, 8-tert-butyl-6,7-dihydropyrolo[3,2-e]5-methylpyrazolo [1,5-a]pyrimidine-3-carbonitrile (LP-805, greater than 0.1 microM) hyperpolarized the muscle membrane in both proximal (diameter, 1-1.2 mm) and distal (diameter, 0.1-0.2 mm) regions of intact (+E) tissue, in which endothelium is present, and endothelium-denuded (-E) tissue. LP-805-induced hyperpolarization was inhibited by glibenclamide. In -E tissues in both regions, acetylcholine (ACh, greater than 0.1 microM) depolarized the membrane, and LP-805 inhibited the depolarization. However, in +E tissues, ACh (greater than 0.1 microM) transiently hyperpolarized the membrane that was not modified by glibenclamide (10 microM), charybdotoxin (100 nM), and NG-nitro-L-arginine (L-NNA, 100 microM). In -E tissues of both regions, LP-805 consistently inhibited the 10 microM ACh-induced contraction (IC50, 2.8 microM), and 10 microM glibenclamide shifted this concentration-response curve to the right (IC50, 20 microM). In +E...
Role of the area postrema in the modulation of the baroreflex control of heart rate by angiotensin II.
Authors: SMatsukawa, I AReid
Journal: Circulation Research (1990)

During angiotensin II (Ang II)-induced elevation of arterial pressure, there is an attenuation of the baroreflex control of heart rate (HR), but the site of this action of Ang II on the baroreflex is not known. To investigate the role of the area postrema, the effects of Ang II on arterial pressure and HR and on the baroreflex control of HR were compared in intact and area postrema-lesioned conscious rabbits. In intact rabbits, infusion of Ang II (2.5-100 ng/kg/min) produced dose-related increases in mean arterial pressure (MAP); the largest dose increased MAP by 32 +/- 3 mm Hg. HR decreased only at the highest dose of Ang II (21 +/- 6 beats/min). In lesioned rabbits, the increase in MAP was reduced (23 +/- 2 mm Hg, p less than 0.05) while the decrease in HR was enhanced (50 +/- 8 beats/min, p less than 0.01). The pressor and HR responses to infusion of phenylephrine (PE) (2-20 micrograms/kg/min) were not different between the two groups. In intact rabbits, the slope of the relation between HR and MAP dur...
Growth-promoting effects of substance P on endothelial cells in vitro. Synergism with calcitonin gene-related peptide, insulin, and plasma factors.
Authors: A CVillablanca, C JMurphy, T WReid
Journal: Circulation Research (1994)

The purpose of this study was to determine the effects of the vasoactive perivascular neuropeptide substance P (SP) on the growth and function of vascular endothelial cells in serum-free culture conditions with cells quiescent in the G0-G1 phase of the cell cycle and to characterize the response. In addition, interactions between SP and other growth factors and neuropeptides including insulin, platelet factors, neurokinin A, neurokinin B, and calcitonin gene-related peptide (CGRP) were studied on endothelial cell growth and compared. Growth effects were determined by stimulation of tritiated thymidine incorporation into DNA and cell proliferation. SP exhibited differential effects on cell growth that were a function of concentration, incubation time, interaction with other growth factors, and cell culture conditions. DNA synthesis in response to SP showed a bell-shaped distribution with a maximal effect that was 10.5-fold over control at 500 micrograms/mL of SP after 48 hours of incubation. The effect sho...
Product inhibition of the actomyosin subfragment-1 ATPase in skeletal, cardiac, and smooth muscle.
Authors: J SDrew, V AHarwalkar, L AStein
Journal: Circulation Research (1992)

We studied product inhibition of the actin-activated ATPase of myosin subfragment-1 (S-1) from the three types of muscle tissue: skeletal, cardiac, and smooth. Increasing levels of [MgADP] in the 0-1-mM range caused significant inhibition of the actin-activated MgATPase activity of cardiac and gizzard but not skeletal muscle S-1. When total nucleotide concentration ([ATP] + [ADP]) was kept constant at 1 mM, ATPase activity was inhibited by 50% at an ADP/ATP ratio of 6:1 for cardiac S-1 and 3:1 for gizzard S-1. For skeletal S-1, however, even a 19:1 ratio did not cause 50% inhibition of ATPase activity. The observed effect was not due to changes in pH or inorganic phosphate concentration, nor could it be explained by substrate (ATP) depletion. In the absence of actin, ADP had little or no inhibitory effect on the ATPase activity of S-1, and these observations imply that ADP is competing directly for the ATP binding site of the actin-S1 complexes of cardiac and smooth muscle S-1. ADP has previously been sho...
Changes in cerebrovascular prostaglandins and thromboxane as a function of systemic blood pressure. Cerebral blood flow autoregulation of the newborn.
Authors: SChemtob, KBeharry, JRex, D RVarma, J VAranda
Journal: Circulation Research (1990)

Cerebrovascular concentrations of prostaglandin E (PGE), prostaglandin F2 alpha (PGF2 alpha), 6-ketoprostaglandin F1 alpha (6-keto-PGF1 alpha), and thromboxane B2 (TXB2) were determined over a blood pressure range of 17-117 mm Hg (induced by inflation of balloon-tipped catheters placed in the thoracic descending aorta and at the aortic root) in eight newborn piglets to access the role of prostanoids in cerebral blood flow (CBF; measured using radioactive microspheres) autoregulation. Basal systemic blood pressure, heart rate, blood gases, total CBF, and prostanoid concentrations were stable. CBF was constant between 50 and 90 mm Hg, but beyond this range CBF varied directly with blood pressure (tau = 0.48; p less than 0.05). Sagittal sinus concentrations of PGE, PGF2 alpha, and 6-keto-PGF1 alpha varied with blood pressure according to a quadratic function (R2 = 0.92 to 0.96; p less than 0.0001), exhibiting lowest values between mean blood pressures of 60 and 90 mm Hg. During hypotension (17-49 mm Hg), the...
Imaging of protein kinase C distribution and translocation in living vascular smooth muscle cells.
Authors: R AKhalil, K GMorgan
Journal: Circulation Research (1991)

The subcellular distribution of protein kinase C was directly imaged in single living smooth muscle cells using a new fluorescent protein kinase C probe. The probe localized prominently to perinuclear organelles and, to a lesser extent, to the cytosol and surface membrane. The perinuclear signal did not detectably change over the time observed. The ratio between the surface membrane intensity and that in the cytosol (R) was measured in parallel with cell shortening. In 1 mM extracellular Ca2+, the time to peak R and time to peak shortening were not significantly different. In Ca(2+)-free solution, no significant increase in the surface membrane/cytosol fluorescence ratio was observed with time, and shortening was inhibited. These results provide a new method for monitoring protein kinase C localization in living cells and directly demonstrate that protein kinase C moves in a Ca(2+)-dependent fashion from the cytosol to the surface membrane simultaneously with contraction.
Further observations on transient entrainment: importance of pacing site and properties of the components of the reentry circuit.
Authors: KOkumura, R WHenthorn, A EEpstein, V JPlumb, A LWaldo
Journal: Circulation (1985)

Transient entrainment of circus-movement tachycardia utilizing an atrioventricular (AV) bypass pathway was studied in 13 patients (nine with the orthodromic form, two with the antidromic form, and two with both the orthodromic and antidromic forms). All patients had a left-sided AV bypass pathway. Pacing at selected rates faster than the spontaneous rate was performed during the tachycardia at a site proximal or distal to the AV node, an area of slow conduction within the reentry loop. Rapid pacing from a site proximal to the AV node (from the right atrium during the orthodromic form of the arrhythmia or the right ventricle during the antidromic form of the arrhythmia) always demonstrated at least one of the three entrainment criteria: constant fusion beats except for the last captured beat, which was entrained but not fused (first criterion); progressive fusion (second criterion); localized conduction block to a site(s) for 1 paced beat associated with interruption of the tachycardia followed by activati...
Present State of Medicine
Authors: C. C. Lutton, W. Leadbitter, R. Robertson, A. D. Mitchel, J. Wilson, I. Tuton, A. Somerville, I. McLean, J. Lorimer, H. Noble, R. Condie, I. Gordon, A. Watson, C. Magill, K. McLean, A. Binnie, M. Binnie, I. Sutherland, T. Preston, B. Brown, B. Walker, J. Symonds, G. Kennedy, J. Milne, I. Clark, P. Gordon, A. M. Moir, I. M. Gill, A. El Nomani, J. R. Lorimer, L. W. Laurenson
Journal: BMJ (1964)
Two-dimensional echocardiographic assessment of electrocardiographic criteria for right atrial enlargement.
Authors: W CReeves, WHallahan, E JSchwiter, T JCiotola, EBuonocore, WDavidson
Journal: Circulation (1981)

Right atrial (RA) size was determined with two-dimensional echocardiography using the apical four-chamber view in 45 adult patients with various echocardiographic criteria for RA enlargement and in 25 normal controls. RA size varied from 11.4-24.0 cm2 (mean 16.1 cm2) in controls. RA enlargement (greater than or equal to 25 cm2) was found in only two of 11 patients with P pulmonale (predictive value [PV] = 18%) and one of five with prominent positive P-wave forces in lead V1 (PV = 20%). However, RA enlargement ws found in eight of eight patients with a qR pattern in lead V1 in the absence of clinical indications of coronary artery disease (PV = 100%). RA enlargement was also found in 13 of 28 patients with a total QRS amplitude in lead V1 of 6 mm or less and a threefold or greater ratio of total QRS amplitude in lead V2 relative to that in V1(V2/V1 greater than or equal to 3) (PV = 48%). A V2/V1 ratio of 4 or more detected 11 of 13 patients with RA enlargement, with six false-positive diagnoses (sensitivit...
Pressure-induced myogenic activation of cat cerebral arteries is dependent on intact endothelium.
Authors: D RHarder
Journal: Circulation Research (1987)

These studies were designed to determine the role of cerebral vascular endothelium in the myogenic depolarization and contraction observed in isolated cat middle cerebral arteries exposed to high transmural pressures. With intact endothelial cells we observed, on elevation of transmural pressure in cannulated isolated arteries, significant membrane depolarization, action potential generation, and reduction in internal diameter. After perfusion of the same vessels with collagenase and elastase for short periods of time to disrupt the endothelial layer, all previous responses to elevation of transmural pressure were no longer seen. Even though enzyme perfusion had no effect on membrane potential at control levels of transmural pressure, it abolished the pressure-dependent depolarization, action potential generation, and constriction. Furthermore, the contractile response to agonist stimulation was maintained after endothelial disruption via enzymes, showing that this method of endothelial disruption did...