tbuckley/cabot-search huggingface dataset:
Effect of prosthetic valve malfunction on the Doppler-catheter gradient relation for bileaflet aortic valve prostheses.
Authors: HBaumgartner, HSchima, PKühn
Journal: Circulation (1993)

BACKGROUNDConsiderable discrepancies between Doppler and catheter gradients caused by localized gradients and pressure recovery have been reported for normal bileaflet aortic valve prostheses.METHODS AND RESULTSTo examine whether this Doppler-catheter gradient relation is affected by prosthetic valve malfunction, a 19-mm CarboMedics aortic valve was simultaneously studied with continuous-wave Doppler and catheter technique in normal function and in various states of malfunction ranging from slightly restricted opening to total occlusion of one leaflet. For each functional status, peak and mean gradients were measured at eight different flow rates (cardiac output, 2.0-6.0 L/min). Excellent correlation between Doppler and catheter gradients was found regardless of the valve function (r = 0.99, SEE = 1.0-3.3 mm Hg). However, the relation between Doppler and catheter gradient was highly dependent on the function of the valve as shown by a variation of slopes from 1.08 to 2.08. For the normally functioning val...
Influence of serum cholesterol and other coronary risk factors on vasomotion of angiographically normal coronary arteries.
Authors: CSeiler, O MHess, MBuechi, T MSuter, H PKrayenbuehl
Journal: Circulation (1993)

BACKGROUNDIt has been shown that there is impairment of the vasodilatory response to acetylcholine in patients with hypercholesterolemia and angiographically normal coronary arteries. Moreover, in patients with angiographically smooth coronary arteries, the number of coronary risk factors is associated with a loss of endothelium-dependent vasodilation. The purpose of the present analysis was to evaluate in patients with and without coronary artery disease coronary vasomotor response to dynamic exercise in angiographically normal and stenosed coronary arteries and to relate the response to serum cholesterol levels as well as to other coronary risk factors.METHODS AND RESULTSLuminal area change during exercise (delta-ex, percent change compared with rest = 100%) was determined by biplane quantitative coronary arteriography in three groups: Group 1 consisted of 14 patients with normal total serum cholesterol of < 200 mg/100 mL; mean, 173 mg/100 mL (mean age, 51 years). Group 2 comprised 23 patients with a sl...
Iloprost inhibits neutrophil function in vitro and in vivo and limits experimental infarct size in canine heart.
Authors: P JSimpson, JMickelson, J CFantone, K PGallagher, B RLucchesi
Journal: Circulation Research (1987)

The prostacyclin analogue iloprost (ZK 36374) inhibits neutrophil activation in vitro, reduces neutrophil accumulation in inflammatory skin lesions, and reduces ultimate infarct size in an anesthetized open-chest canine model of regional ischemia and reperfusion. Iloprost (0.1-100 microM) inhibited the in vitro production of superoxide anion by canine neutrophils in a concentration-dependent manner. Iloprost (100 ng/kg/min i.v.) inhibited C5a-induced neutrophil migration into inflammatory skin lesions as assessed by the neutrophil-specific enzyme marker, myeloperoxidase. The myeloperoxidase activity determined 2 hours after the intradermal administration of C5a in each of the groups was control 13.3 +/- 1.8 units/g tissue (n = 12) and iloprost 6.5 +/- 0.9 units/g (n = 12), p less than 0.01. Iloprost was administered to anesthetized open-chest dogs (100 ng/kg/min) 10 minutes after left circumflex coronary artery (LCCA) occlusion and continued during the 90-minute occlusion period and the first 2 hours of r...
Depression of contractility following stretches and releases applied during contraction to single frog atrial cardiac cells.
Authors: MTarr, J WTrank, K KGoertz
Journal: Circulation Research (1984)

The effects of stretches and releases on the contractile performance of isolated single frog atrial cells (Rana catesbeiana) were investigated. A stretch or release was imposed on the cell--either during a contraction (test) or before the onset of contraction (control)--and the contractile performance (length, velocity and force) of the test contraction was compared with that of the control contraction to determine whether the stretch or release imposed on the contracting cell altered the contractility of the cell. We found that the velocity of cell (and sarcomere) shortening for the remainder of the test contraction following either a stretch or release was markedly less than that occurring at the same time in the control contraction. This decreased velocity occurred even though the force in the test contraction was less than that in the control contraction and the sarcomere length was longer in the test contraction than in the control contraction. These results indicate that after a stretch or release i...
Intramural reentry as a mechanism of ventricular tachycardia during evolving canine myocardial infarction.
Authors: J BKramer, J ESaffitz, F XWitkowski, P BCorr
Journal: Circulation Research (1985)

We evaluated the contribution of intramural electrical events in initiation and maintenance of ventricular tachycardia in 15 dogs 3-8 days after either permanent (n = 2) or transient (n = 13) coronary artery occlusion. Seven of the dogs (47%) demonstrated eight distinct monomorphic ventricular tachycardia patterns which were mapped by means of a recently designed computerized system capable of simultaneously detecting, storing, and assessing information from 232 individual cardiac sites. Using both epicardial and intramural electrodes, we found definitive evidence for intramural reentry in seven of the eight monomorphic tachycardias analyzed. Furthermore, five of these animals (71%) demonstrated microreentry, in which small epicardial conduction loops exited intermittently into nonrefractory subendocardium to initiate succeeding beats, while, in the remaining two dogs, ventricular tachycardia was due to macroreentry, during which the broad subendocardial wavefronts depolarizing the ventricle constituted t...
Digital angiography in the pediatric patient with congenital heart disease: comparison with standard methods.
Authors: A RLevin, H LGoldberg, J SBorer, L NRothenberg, F ANolan, M AEngle, BCohen, N TSkelly, JCarter
Journal: Circulation (1983)

Digital subtraction angiography (DSA) permits high-resolution cardiac imaging with relatively low doses of contrast medium and reduced radiation exposure. These are potential advantages in children with congenital heart disease. Computer-based DSA (30 frames/sec) and conventional cutfilm angiography (6 frames/sec) or cineangiography (60 frames/sec) were compared in 42 patients, ages 2 months to 18 years (mean 7.8 years) and weighing 3.4 to 78.5 kg (mean 28.2 kg). There were 29 diagnoses that included valvular regurgitant lesions, obstructive lesions, various shunt abnormalities, and a group of miscellaneous anomalies. For injections made at a site distant from the lesion and on the right side of the circulation, the mean dose of contrast medium was 60% to 100% of the conventional dose given during standard angiography. With injections made close to the lesion and on the left side of the circulation, the mean dose of contrast medium was 27.5% to 42% of the conventional dose. Radiation exposure for each tec...
Late potentials detected after myocardial infarction: natural history and prognostic significance.
Authors: D LKuchar, C WThorburn, N LSammel
Journal: Circulation (1986)

The risk of developing spontaneous ventricular tachycardia (VT) and/or sudden death (arrhythmic events) was prospectively assessed in 165 patients who survived acute myocardial infarction. Signal-averaged electrocardiograms (ECGs) were performed before hospital discharge and then serially at regular intervals over the following year. In addition, 24 hr Holter monitoring was performed and left ventricular ejection fraction was determined. Sixty-five patients (group 1) had abnormal signal-averaged ECGs (voltage in the last 40 msec of the filtered QRS less than 20 microV or filtered QRS duration greater than 120 msec), 92 had normal signal-averaged ECGs (group 2), and eight had bundle branch block (excluded from analysis). In group 1, spontaneous normalization of the voltage in the last 40 msec of the QRS complex occurred in 30% of patients after 12 months, although total filtered QRS duration did not change overall. During follow-up of up to 20 months (median 11), seven patients died suddenly and six pres...
Myocardial consequences of coronary artery bypass graft surgery. The paradox of necrosis in areas of revascularization.
Authors: B HBulkely, G MHutchins
Journal: Circulation (1977)

Myocardial infarction after coronary artery bypass graft (CABG) surgery has been described clinically in up to 30% of patients but there is little morphologic information about the character and pathogenesis of the myocardial injury. We studied myocardium in the distribution of bypassed and nonbypassed coronary arteries for the presence of contraction band necrosis as compared to coagulation necrosis, in 58 autopsied patients who died less than 1 month after surgery. Operation related necrosis consisting of focal subendocardial contraction band necrosis was present to some degree in 48 (83%) patients. Regional transmural necrosis was present in 22 (38%) patients and was of two types. Contraction band necrosis occurred in 18 patients and was in the distribution of a patent bypassed coronary artery in 15 of them. Coagulation necrosis was found in four patients, and in each was in the distribution of a new graft-releated coronary artery occlusion. The results suggest that coronary artery reflow through widel...
Re: Cervical Carcinoma and Human Papillomavirus: On the Road to Preventing a Major Human Cancer
Authors: F. X. Bosch, N. Munoz, S. de Sanjose, E. L. F. Franco, D. R. Lowy, M. Schiffman, S. Franceschi, S. K. Kjaer, C. J. L. M. Meijer, I. H. Frazer, J. Cuzick
Journal: JNCI Journal of the National Cancer Institute (2001)
High density lipoprotein reverses inhibitory effect of oxidized low density lipoprotein on endothelium-dependent arterial relaxation.
Authors: YMatsuda, KHirata, NInoue, MSuematsu, SKawashima, HAkita, MYokoyama
Journal: Circulation Research (1993)

We have recently reported that oxidized low density lipoprotein (ox-LDL) inhibits endothelium-dependent arterial relaxation through its increased lysophosphatidylcholine (LPC). In this study we examined whether high density lipoprotein (HDL) has any effect on the inhibition of endothelium-dependent relaxation by ox-LDL in isolated strips of rabbit thoracic aorta. Both low density lipoprotein (LDL) and HDL were isolated from normal human plasma, and LDL was oxidized by exposure to copper. Preincubation of arterial strips with ox-LDL (0.1-0.5 mg protein/ml) inhibited endothelium-dependent relaxation to acetylcholine (ACh) in a concentration-dependent manner. HDL (1 mg protein/ml) by itself had no effect on the relaxation to ACh. In the presence of HDL, the inhibition by ox-LDL was markedly reduced. Although synthetic L-alpha-palmitoyl LPC (5 micrograms/ml) completely abolished a relaxation to ACh, the preincubation of arterial strips with HDL completely prevented the LPC-induced inhibition. Moreover, a rela...
The physiologic basis of dobutamine as compared with dipyridamole stress interventions in the assessment of critical coronary stenosis.
Authors: A YFung, K PGallagher, A JBuda
Journal: Circulation (1987)

Noninvasive cardiac imaging with echocardiography or thallium-201 scintigraphy utilizing pharmacologic agents as alternatives to exercise is gaining popularity. We investigated the physiologic rationale underlying the optimal choice of pharmacologic stress for functional versus perfusion imaging. With the use of an open-chest dog model, a critical stenosis of the left circumflex coronary artery was produced with total ablation of hyperemic response to a 15 sec period of complete occlusion. Regional left ventricular wall thickening was assessed by quantitative two-dimensional echocardiography. Regional myocardial blood flow was determined by microspheres in both the flow-restricted left circumflex area and the control area supplied by the left anterior descending artery. Eight dogs received 15 micrograms/kg/min dobutamine intravenously for 10 min, and nine dogs received 0.14 mg/kg/min dipyridamole intravenously for 4 min. Dobutamine induced wall thickening abnormalities in all dogs while dipyridamole induc...
Neutralization of SARS-CoV-2 Variants B.1.429 and B.1.351
Authors: Xiaoying Shen, Haili Tang, Rolando Pajon, Gale Smith, Gregory M Glenn, Wei Shi, Bette Korber, David C Montefiori
Journal: New England Journal of Medicine (2021)

Cross-Reactive Neutralization of SARS-CoV-2 Variants An analysis of cross-reactive viral binding and neutralization of emerging SARS-CoV-2 variants, modeled with the use of pseudoviruses, suggests ...
Neither dorsal root nor baroreceptor afferents are necessary for eliciting the renal responses to acute intravascular volume expansion in the primate Macaca fascicularis.
Authors: J PGilmore, T VPeterson, I HZucker
Journal: Circulation Research (1979)

We determined the contribution of the dorsal roots, vagi, and sino-aortic nerves to the renal responses to acute isotonic, isooncotic intravascular volume expansion in the nonhuman primate, Macaca fascicularis. Expansion of the estimated blood volume by 15% produced a significant natriuresis and diuresis. There was no significant difference between the time to peak response for either. Neither dorsal rhizotomy (C6-T7) nor vagotomy and sino-aortic denervation had a significant effect on these responses. We conclude that these pathways are not necessary for eliciting the renal responses to hypervolemia in the nonhuman primate.
Endoscopic Mucosal Resection (Emr) of Colonic Polyps in the Older Patient – is it Safe?
Authors: T Garvey, A Hadjinicolaou, M Frank, V Nadesalingam, E McDermott
Journal: Endoscopy (2021)

Aims Controversies surround the risk of performing endoscopic mucosal resection (EMR) in patients ≥ 75 years coupled with difficulties encountered with co-morbidities which are often heavily prevalent in this population. We sought to analyse the safety of EMR of large colonic polyps (20mm or greater) in patients ≥ 75 years.
電話伝送型心電図によりモニターした持続性心房細動患者におけるベプリジルの用量-反応効果 多施設無作為プラセボ対照二重盲検試験(J-BAF試験)
Authors: Yamashita Takeshi, Ogawa Satoshi, Sato Toshiaki, Aizawa Yoshifusa, Atarashi Hirotsugu, Fujiki Akira, Inoue Hiroshi, Ito Makoto, Katoh Takao, Kobayashi Youichi, Koretsune Yukihiro, Kumagai Koichiro, Niwano Shinichi, Okazaki Osamu, Okumura Ken, Saku Keijiro, Tanabe Teruhisa, Origasa Hideki
Journal: Circulation (2009)
Limitation of myocardial ischemia by collateral circulation during sudden controlled coronary artery occlusion in human subjects: a prospective study.
Authors: MCohen, K PRentrop
Journal: Circulation (1986)

We have shown improvement in collateral filling immediately after sudden controlled coronary occlusion in human subjects undergoing elective coronary angioplasty. It has been suggested but not proved that collateral circulation can limit myocardial ischemia. We prospectively studied 23 patients with isolated left anterior descending (n = 14) or right coronary (n = 9) disease and normal left ventriculograms during elective coronary angioplasty. A second arterial catheter was used for injection of the contralateral artery to assess collateral filling before balloon placement and during coronary occlusion by balloon inflation. Left ventriculography was performed during another inflation. Grading of collateral filling was as follows: 0 = none, 1 = filling of side branches only, 2 = partial filling of the epicardial segment, 3 = complete filling of the epicardial segment. Indexes of myocardial ischemia included percent of the left ventricular perimeter showing new hypocontractility and the sum of ST segment el...
Effects of propranolol and diltiazem alone and in combination on the recovery of left ventricular segmental function after temporary coronary occlusion and long-term reperfusion in conscious dogs.
Authors: L RBush, L MBuja, GTilton, MWathen, PApprill, JAshton, J TWillerson
Journal: Circulation (1985)

We evaluated the ability of propranolol and diltiazem alone and in combination to enhance the recovery of left ventricular (LV) segmental function during 1 month of reperfusion after two temporary occlusions of the left anterior descending coronary artery (LAD) in conscious dogs instrumented with ultrasonic crystals for the measurement of regional net systolic wall thickening (NET). LV segments were classified according to their contractile function after 1 hr of LAD occlusion: class 1, greater than 67% of preocclusion (control) NET; class 2, 0% to 66.9%; class 3, less than 0% (paradoxical systolic wall thinning). Propranolol (1 mg/kg iv) or diltiazem (20 micrograms/kg/min) was given 65 min after LAD occlusion in dogs that had 2 (group I) or 4 hr (group II) of LAD occlusion. Diltiazem plus propranolol (same doses) were given to another group of dogs that underwent 4 hr (but not 2) of LAD occlusion. Untreated control dogs received 25 ml of saline and underwent 2 or 4 hr of LAD occlusion. The NET of class 2...
A randomized trial of late reperfusion therapy for acute myocardial infarction. Thrombolysis and Angioplasty in Myocardial Infarction-6 Study Group.
Authors: E JTopol, R MCaliff, MVandormael, C LGrines, B SGeorge, M LSanz, TWall, MO'Brien, MSchwaiger, F VAguirre
Journal: Circulation (1992)

BACKGROUNDExperimental and observational clinical studies of acute coronary occlusion have suggested that late reperfusion prevents infarct expansion and facilitates myocardial healing. The purpose of this trial was to assess whether infarct vessel patency could be achieved in late-entry patients and what benefit, if any, can be demonstrated.METHODS AND RESULTSIn a double-blind fashion, 197 patients with 6 to 24 hours of symptoms and ECG ST elevation were randomly assigned to tissue-type plasminogen activator (100 mg over 2 hours) or placebo. Coronary angiography within 24 hours was used to determine infarct vessel patency status. Patients with infarct-related occluded arteries were then eligible for a second randomization to either angioplasty (34 patients) or no angioplasty (37 patients). Ventricular function and cavity size were reassessed at 1 month by gated blood pool scintigraphy and at 6 months by repeat cardiac catheterization. The primary end point, infarct vessel patency, was 65% for plasminogen...
Effect of propranolol after acute myocardial infarction in patients with congestive heart failure.
Authors: KChadda, SGoldstein, RByington, J DCurb
Journal: Circulation (1986)

The incidence of congestive heart failure was studied in the Beta Blocker Heart Attack Trial in which postmyocardial infarction patients between the ages of 30 and 69 years, with no contraindication to propranolol, were randomly assigned to receive placebo (n = 1921) or propranolol 180 or 240 mg daily (n = 1916) 5 to 21 days after admission to the hospital for the event. Survivors of acute myocardial infarction with compensated or mild congestive heart failure, including those on digitalis and diuretics, were included in the study. A history of congestive heart failure before randomization characterized 710 (18.5%) patients: 345 (18.0%) in the propranolol group and 365 (19.0%) in the placebo group. The incidence of definite congestive heart failure after randomization and during the study was 6.7% in both groups. In patients with a history of congestive heart failure before randomization, 51 of 345 (14.8%) in the propranolol group and 46 of 365 (12.6%) in the placebo group developed congestive heart failu...
Investigation of genesis of gallop sounds in dogs by quantitative phonocardiography and digital frequency analysis.
Authors: A EAubert, B GDenys, FMeno, P SReddy
Journal: Circulation (1985)

Several investigators have noted external gallop sounds to be of higher amplitude than their corresponding internal sounds (S3 and S4). In this study we hoped to determine if S3 and S4 are transmitted in the same manner as S1. In 11 closed-chest dogs, external (apical) and left ventricular pressures and sounds were recorded simultaneously with transducers with identical sensitivity and frequency responses. Volume and pressure overload and positive and negative inotropic drugs were used to generate gallop sounds. Recordings were made in the control state and after the various interventions. S3 and S4 were recorded in 17 experiments each. The amplitude of the external S1 was uniformly higher than that of internal S1 and internal gallop sounds were inconspicuous. With use of Fourier transforms, the gain function was determined by comparing internal to external S1. By inverse transform, the amplitude of the internal gallop sounds was predicted from external sounds. The internal sounds of significant amplitude...
Human connexin43 gap junction channels. Regulation of unitary conductances by phosphorylation.
Authors: A PMoreno, J CSáez, G IFishman, D CSpray
Journal: Circulation Research (1994)

Connexin43 is the major gap protein in the heart and cardiovascular system. Single channel recordings of human connexin43 gap junction channels exogenously expressed in transfected SKHep1 cells demonstrate two discrete classes of channel events, with unitary conductances of predominantly 60 to 70 and 90 to 100 pS when recorded with an internal solution containing CsCl as the major current-carrying ionic species and at moderate transjunctional voltages (< 60 mV). Human connexin43 expressed in SKHep1 cells displays multiple electrophoretic mobilities (apparent M(r), approximately 41 to 45 kD) when resolved in Western blots. Treatment of connexin43 from these cells with alkaline phosphatase collapses the bands into a single 41-kD species; application of alkaline phosphatase to the cell interior through patch pipettes yields channels that are predominantly of the larger unitary conductance. The smaller 60- to 70-pS unitary conductance values correspond to the most common channel size seen in cultured rat card...
Cardiac tamponade in left ventricular dysfunction.
Authors: B DHoit, MGabel, N OFowler
Journal: Circulation (1990)

Echocardiographic and hemodynamic data were measured in closed-chest dogs during graded cardiac tamponade (pericardial pressure 5, 10, and 15 mm Hg) before and after production of diffuse ischemic left ventricular dysfunction. Left ventricular dysfunction was produced by intracoronary injection of nonradioactive microspheres (54 +/- 3.9 mm diameter). Changes in left atrial pressure with cardiac tamponade were influenced by coexisting left ventricular dysfunction. Left atrial pressure increased with tamponade and was equal to pericardial pressure before left ventricular dysfunction was produced. However, after left ventricular dysfunction was produced, left atrial pressure was significantly higher than pericardial pressure before tamponade, but it fell toward pericardial pressure when tamponade was produced. Pulsus paradoxus (greater than 10 mm Hg) was present in all animals with cardiac tamponade before left ventricular dysfunction but in only one animal afterward. During each level of tamponade, the insp...