tbuckley/cabot-search huggingface dataset:
Stress echocardiography in the detection of myocardial ischemia. Head-to-head comparison of exercise, dobutamine, and dipyridamole tests.
Authors: B DBeleslin, MOstojic, JStepanovic, ADjordjevic-Dikic, SStojkovic, MNedeljkovic, GStankovic, ZPetrasinovic, LGojkovic, ZVasiljevic-Pokrajcic
Journal: Circulation (1994)

BACKGROUNDExercise and pharmacological stress echocardiography have emerged as convenient alternatives to myocardial scintigraphy. The objective of this study was to compare in the same patients the diagnostic values of exercise, dobutamine, and dipyridamole stress echocardiography tests for detection of myocardial ischemia.METHODS AND RESULTSWe performed exercise (maximal treadmill Bruce protocol), dobutamine (up to 40 micrograms/kg per minute) and dipyridamole (up to 0.84 mg/kg over 10 minutes) stress echocardiography tests, in random sequence and on separate days, in 136 consecutive patients. All patients underwent coronary angiography. Significant coronary artery disease was defined by quantitative coronary angiography as a lesion with a diameter stenosis > or = 50%. A stress echocardiogram was considered positive when new or worsening of preexisting wall motion abnormality was observed. Most of the patients (94%) were receiving the same antianginal medication for each stress test; 59 patients were re...
The utility of endogenous glycochenodeoxycholate-3-sulfate and 4β-hydroxycholesterol to evaluate the hepatic disposition of atorvastatin in rats
Authors: Yanrong Ma, Mingyan Xin, Yuanjie Wen, Huan Wang, Guoqiang Zhang, Jianye Dai, Xin-An Wu
Journal: Asian Journal of Pharmaceutical Sciences (2021)

The liver is an important organ for drugs disposition, and thus how to accurately evaluate hepatic clearance is essential for proper drug dosing. However, there are many limitations in drug dosage adjustment based on liver function and pharmacogenomic testing. In this study, we evaluated the ability of endogenous glycochenodeoxycholate-3-sulfate (GCDCA-S) and 4β-hydroxycholesterol (4β-HC) plasma levels to evaluate organic anion-transporting polypeptide (Oatps)-mediated hepatic uptake and Cyp3a-meidated metabolism of atorvastatin (ATV) in rats. The concentration of ATV and its metabolites, 2-OH ATV and 4-OH ATV, was markedly increased after a single injection of rifampicin (RIF), an inhibitor of Oatps. Concurrently, plasma GCDCA-S levels were also elevated. After a single injection of the Cyp3a inhibitor ketoconazole (KTZ), plasma ATV concentrations were significantly increased and 2-OH ATV concentrations were decreased, consistent with the metabolism of ATV by Cyp3a. However, plasma 4β-HC was not affected by KTZ treatment despite it being a Cyp3a metabolite of cholesterol. After repeated oral administration of RIF, plasma concentrations of ATV, 2-OH ATV and 4-OH ATV were markedly increased and the hepatic uptake ratio of ATV and GCDCA-S was decreased. KTZ did not affect plasma concentrations of ATV, 2-OH ATV and 4-OH ATV, but significantly decreased the metabolic ratio of total and 4-OH ATV. However, the plasma level and hepatic metabolism of 4β-HC were not changed by KTZ. The inhibition of hepatic uptake of GCDCA-S by RIF was fully reversed after a 7-d washout of RIF. Plasma concentration and hepatic uptake ratio of GCDCA-S were correlated with the plasma level and hepatic uptake of ATV in rats with ANIT-induced liver injury, respectively. These results demonstrate that plasma GCDCA-S is a sensitive probe for the assessment of Oatps-mediated hepatic uptake of ATV. However, Cyp3a-mediated metabolism of ATV was not predicted by plasma 4β-HC levels in rats.
Detection of left atrial myxoma by gated radionuclide cardiac imaging.
Authors: G MPohost, J OPastore, K AMcKusick, P NChiotellis, G ZKapellakis, G SMyers, R EDinsmore, P CBlock
Journal: Circulation (1977)

Gated radionuclide cardiac blood pool scans (GCS) of end-systole and end-diastole or eight images subtending the entire cardiac cycle were performed on seven patients with left atrial myxomas documented by pulmonary cineangiography with left atrial follow-through. The ethocardiogram was either suggestive or diagnostic in all patients. In addition to demonstration of the tumor (6 patients), the GCS detected three patterns of tumor motion: 1) a defect which moved from the left atrium in end systole to the left ventricle in end diastole (2 patients); 2) a defect which remained within the region of the left atrium but decreased in size between end diastole and end systole (3); and 3) a defect which was observed within the region of the left ventricle in end diastole but disappeared in end systole (1). Thus, the GCS is a noninvasive method for detection and evaluation of motion of left atrial myxomas.
Kinetics of cellular proliferation after arterial injury. IV. Heparin inhibits rat smooth muscle mitogenesis and migration.
Authors: A WClowes, M MClowes
Journal: Circulation Research (1986)

Heparin inhibits the development of intimal thickening after carotid injury in the rat; however, the specific cellular events responsible for this effect have not been defined. In this study, smooth muscle cell growth fraction and migration into the intima were quantitatively measured in heparin-treated animals. All rats were subjected to left carotid balloon injury and received continuous intraperitoneal infusion of tritiated thymidine; they were given either heparin or lactated Ringer's solution intravenously for periods of time up to 7 days. Both smooth muscle cell growth fraction and migration of nondividing smooth muscle cells were markedly reduced in heparin-treated rats. If heparin was administered for only the first 3 days after carotid injury, both smooth muscle growth fraction and migration were reduced at 7 days; on the other hand, heparin had no effect on growth fraction and migration if given from day 4 to day 7. Finally, heparin given for a period of 1 week produced marked reduction in smoot...
Magnetic measurement of S-T and T-Q segment shifts in humans. Part II: Exercise-induced S-T segment depression.
Authors: DCohen, PSavard, R DRifkin, ELepeschkin, W EStrauss
Journal: Circulation Research (1983)

The direct-current magnetocardiogram, which shows the T-Q (baseline) shift, is used to clarify the cause of S-T depression induced by stress testing in the human heart. Measurements are made of the amount of baseline shift associated with the S-T depression. Results are presented of a well-documented patient, with typical coronary artery disease, undergoing a two-step exercise test. Before exercise, there was no S-T or baseline shift. During exercise, the S-T segment became depressed and the baseline segment was simultaneously elevated, at about 70% of the S-T amplitude. After termination of exercise, the baseline elevation disappeared somewhat more rapidly than the S-T depression. These results were consistent in repeated tests of this patient. Because the baseline shift is a reflection of an injury current, these results confirm the belief that exercise-induced S-T depression is mostly due to an injury current which is interrupted during the S-T interval. The baseline shift seen here is the first non-in...
Analysis of coronary angioplasty practice in the United States with an insurance-claims data base.
Authors: E JTopol, S GEllis, D MCosgrove, E RBates, D WMuller, N JSchork, M ASchork, F DLoop
Journal: Circulation (1993)

BACKGROUNDCoronary angioplasty is frequently performed in the United States, with more than 300,000 procedures in 1990. Despite the high rate of use of the procedure, there have been few studies addressing practice patterns.METHODS AND RESULTSFrom a private insurance claims data base of 5.4 million individuals, a total of 2,101 patients who underwent coronary angioplasty during 1988-1989 were identified. Using their 4,578 hospital admission records and 87,578 outpatient claim records, with an average follow-up of 332 +/- 182 days, we compared patients' outcomes and charges according to whether they had an exercise stress test before the procedure, by sex, by region of the country, and by whether the angioplasty was performed in an institution with a training program. Only 29% of the study cohort had exercise testing before angioplasty; patients in the West (p = 0.001), those undergoing multivessel angioplasty (p = 0.00001), and those whose procedures were performed at sites with training programs (p = 0.0...
A clinical and follow-up study of right and left bundle branch block.
Authors: MRotman, J HTriebwasser
Journal: Circulation (1975)

The experience with bundle branch block at the USAF School of Aerospace Medicine was reviewed. The clinical and follow-up status was evaluated in 394 subjects with right bundle branch block (RBBB) and 125 subjects with left bundle branch block (LBBB). The majority of subjects were asymptomatic at the time of bundle branch block diagnosis. The subjects were divided into subfroups based on electrocardiographic (EEG) findings to determine if any one subfroup was at higher risk for initial or follow-up morbidity of cardiobascular disease or follow-up mortality. At initial diagnosis and clinical evaluation, 94% of RBBB and 89% of LBBB subjects had no evidence of cardiobascular disease. In the RBBB group, 3 and 2% had cornary heart disease and hypertension, respectively; in LBBB subjects, 9 and 7% had cornary heart disease and hypertension, respectively. No one ECG subfroup in either the RBBB or LBBB group had a higher incidence of cardiobascular disease. Complete follow-up information was available in 94% of t...
The estimation of sinoatrial conduction time in rabbit heart by the constant atrial pacing technique.
Authors: A OGrant, GKirkorian, D GBenditt, H CStrauss
Journal: Circulation (1979)

This study compared estimates of sinoatrial conduction time (SACT) obtained by constant atrial pacing (CAP) and premature atrial stimulation (PAS) with measured SACT in isolated rabbit right atrial preparations. Transmembrane potentials and surface electrograms were recorded from the sinus node and crista terminalis, respectively. The crista terminalis was paced 5, 10 and 15 beats/min faster than the spontaneous sinus rate with a train of eight pulses. Estimate of SACT by CAP was taken as the difference between the first atrial return cycle and the mean spontaneous cycle length. SACTs at 5, 10 and 15 beats/min faster were 76 +/- 10, 86 +/- 10 and 96 +/- 10 msec (mean +/- SEM; n = 12), respectively; correlation coefficients with the true SACT were 0.7, 0.54 and 0.4. Consecutive determinations of SACT by PAS and CAP in the same preparation (n = 6) at 10 beats/min faster gave SACTs of 86 +/- 13 and 79 +/- 14 msec, respectively, compared with true SACTs of 79 +/- 10 msec. Shortening of sinus node action poten...
Age-related appearance of outward currents may contribute to developmental differences in ventricular repolarization.
Authors: C DJeck, P ABoyden
Journal: Circulation Research (1992)

Ventricular repolarization significantly influences contractility, refractoriness, and ion channel state. Factors affecting repolarization will thus affect these secondary phenomena. To understand the influence of age on ventricular repolarization, we studied neonatal, young, and adult dogs using electrocardiogram, action potential, and whole-cell voltage-clamp recordings from single epicardial myocytes. Hearts of neonatal and 57-58-day-old dogs require a significantly longer time for repolarization than those of adult dogs, as determined by analysis of rate-corrected QT and JT (QT minus QRS) intervals. Epicardial action potentials of neonates are significantly longer than those of adults, as determined by measurements of duration at 50% and 90% repolarization. The adult action potential is characterized by a large phase 1 notch that is absent from neonatal recordings. This notch develops between 58 and 64 days of age, and by 64-68 days of age, it is equal to that in adults. In addition, action potentials...
Separation of the direct myocardial and vasodilator actions of milrinone administered by an intracoronary infusion technique.
Authors: P LLudmer, R FWright, J MArnold, PGanz, EBraunwald, W SColucci
Journal: Circulation (1986)

To determine the relative contributions of milrinone's positive inotropic and vasodilator actions in patients with severe congestive heart failure, the drug was administered by constant infusion directly into the left main coronary artery of 11 patients with New York Heart Association functional class III or IV heart failure. Intracoronary infusion of milrinone at rates up to 50 micrograms/min had no effect on mean arterial pressure or systemic vascular resistance but resulted in dose-related increases in peak positive dP/dt (+21%), stroke volume index (+18%), and stroke work index (+21%) and decreases in heart rate (-3%), mean right atrial pressure (-25%), and left ventricular end-diastolic pressure (-17%). In eight patients, intravenous administration (75 micrograms/kg) after the intracoronary infusion resulted in significant decreases in mean arterial pressure (-14%) and systemic vascular resistance (-40%), further increase in stroke volume index compared with intracoronary administration, and further ...
Endoscopic vs. laparoscopic gastrojejunostomy for duodenal obstruction: a randomized study in a porcine model
Authors: H. Li, E. Linghu
Journal: Endoscopy (2012)

We read with interest the article by von Renteln et al. [1], which reported the feasibility of purely endoscopic gastrojejunostomy in a porcine model and further compared the endoscopic gastrojejunostomy with the laparoscopic technique, concluding that endoscopic anastomoses were comparable in size to laparoscopic ones (1.8 cm vs. 2.0 cm).
Treatment of canine embolic pulmonary hypertension with recombinant tissue plasminogen activator. Efficacy of dosing regimes.
Authors: FShiffman, JDucas, PHollett, EIsraels, DGreenberg, RCook, R MPrewitt
Journal: Circulation (1988)

We investigated effects of two dosing regimes of recombinant tissue plasminogen activator (rt-PA) and sodium heparin on pulmonary thrombolysis in a canine model of pulmonary hypertension, induced by injection of radioactive blood clots. By continuously counting over both lung fields with a mobile gamma camera, we correlated rate and extent of pulmonary thrombolysis with corresponding pulmonary hemodynamics. Treatment with heparin, over a 3-hour interval, did not result in significant thrombolysis or in a decrease in mean pulmonary artery pressure (PAP). In contrast, rt-PA caused marked pulmonary thrombolysis. While total clot lysis was similar when 1 mg/kg rt-PA was infused over 15 (rt-PA15) or 90 (rt-PA90) minutes (47% and 42%, respectively), rate of lysis during infusion was markedly increased with rt-PA15 (56% vs. 27%/hr, p less than 0.001). Corresponding to the increased rate of thrombolysis with rt-PA15, relative PAP decrease was greater at 15 and 30 minutes. At 4 hours, PAP decreased most with rt-PA...
Changes in left ventricular wall motion after coronary artery bypass surgery: signal or noise?
Authors: G MJeppson, P DClayton, T JBlair, H VLiddle, R LJensen, S CKlausner
Journal: Circulation (1981)

We evaluated changes in ventricular wall motion after surgery by comparing smoothed, filtered measurements of regional percent shortening (RPS) from right anterior oblique ventriculograms in 37 patients before and after surgery. After surgery there was a significant (p less than 0.05) decrease in the number of regions with hypokinetic wall motion. The distribution of RPS values was also different (p less than 0.005). However, the mean value of RPS for the surgery group as a whole was not significantly altered. These data were contrasted with RPS data from 11 control patients, who were each studied twice but did not have surgical intervention. Similar analysis of the control group did not show any significant change between studies in the number of hypokinetic regions, and the distributions of RPS for the first and second angiograms were not different. We found a 10.3% absolute mean change in repeated measurements of RPS in the control group. We conclude that significant changes occurred after surgery that...
Cardiovascular response to dynamic exercise in patients with chronic symptomatic mild-to-moderate and severe aortic regurgitation.
Authors: D TKawanishi, C RMcKay, P AChandraratna, MNanna, C LReid, UElkayam, MSiegel, S HRahimtoola
Journal: Circulation (1986)

Fifteen patients with symptomatic mild-to-moderate and severe chronic aortic regurgitation (AR) performed supine bicycle exercise while measurements of rest and exercise hemodynamics and left ventricular function were obtained. A continuous Doppler method was used to determine the change in distribution of total left ventricular stroke volume between forward stroke volume and regurgitant volume (RgV) with exercise. The pulmonary arterial wedge pressure (PAWP) was lower in the mild-to-moderate AR group than in the severe AR group at rest (8 +/- 1.2 vs 19 +/- 3.6 mm Hg, p = 0.01) and during exercise (15 +/- 3.9 vs 30 +/- 4.3 mm Hg, p = .02). In all patients there were increases in heart rate (78 +/- 4 to 96 +/- 5 beats/min, p less than .001), forward stroke volume (41 +/- 2 to 46 +/- 2 ml/m2), and the cardiac index (3.1 +/- 0.2 to 4.4 +/- 0.3 liters/min-m2, p less than .001), despite a fall in total left ventricular stroke volume index from 84 +/- 5 to 76 +/- 5 ml/m2 (p = .03). The systemic vascular resista...
Exercise-induced ST depression in the diagnosis of coronary artery disease. A meta-analysis.
Authors: RGianrossi, RDetrano, DMulvihill, KLehmann, PDubach, AColombo, DMcArthur, VFroelicher
Journal: Circulation (1989)

To evaluate the variability in the reported diagnostic accuracy of the exercise electrocardiogram, we applied meta-analysis to 147 consecutively published reports comparing exercise-induced ST depression with coronary angiography. These reports involved 24,074 patients who underwent both tests. Population characteristics and technical and methodologic factors, including publication year, number of electrocardiographic leads, exercise protocol, use of hyperventilation, definition of an abnormal ST response, exclusion of certain subgroups, and blinding of test interpretation were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity, 68%; range, 23-100%; SD, 16%; and mean specificity, 77%; range, 17-100%; SD, 17%). The four study characteristics found to be significantly and independently related to sensitivity were the treatment of equivocal test results, comparison with a better test such as thallium scintigraphy, exclusion of patients on digitalis, and publication year. ...
Correlative electrophysiological and anatomical studies concerning the site of origin of escape rhythm during complete atrioventricular block in the dog.
Authors: T NJames, J HIsobe, FUrthaler
Journal: Circulation Research (1979)

Complete heart block was produced in eight dogs by the selective perfusion of physostigmine or neostigm into the atrioventricular (AV) node artery. A characteristic escape AV junctional rhythm emerged in each dog. After reversal of the cholinesterase paralysis with atropine, in each dog partial heart block was produced by an incision into the AV nodal region. In three of these eight dogs, a second incision placed slightly more anteriorly produced complete AV block which was followed by the emergence of an escape AV junctional rhythm similar to the one produced pharmacologically. Hearts of these three dogs were examined histologically with serial sections to determine the exact location of the incisions and their relationship to the AV node and His bundle. In each dog the incision that produced complete heart block passed directly through the junction of AV node with His bundle. In this region previous studies had demonstrated numerous P cells, which are thought to be the site of origin of normal cardiac a...
Indium-111 platelet scintigraphy for the diagnosis of acute venous thrombosis.
Authors: M DEzekowitz, C FPope, H DSostman, E OSmith, MGlickman, SRapoport, K WSniderman, GFriedlaender, R RPelker, F BTaylor
Journal: Circulation (1986)

Platelets labeled with indium-111 have been used successfully as a marker of active thrombosis in man. To establish the diagnostic accuracy of platelet scintigraphy in comparison to contrast venography in the diagnosis of acute lower limb venous thrombosis, we evaluated 103 consecutive patients divided into two groups. Platelets were labeled by the indium-111 oxine method. Patients from group I (n = 73, 56 had venograms) were asymptomatic and underwent platelet scintigraphy 1.1 +/- 0.6 days (mean +/- 1 SD) after a major orthopedic procedure. Patients from group II (n = 30, all had venograms) were symptomatic and underwent platelet scintigraphy 1.2 +/- 1.7 days after venography. In group II, 15 patients with positive findings on contrast venography were treated with intravenous heparin; five others with positive venograms did not receive heparin until platelet scintigraphy was completed. Both platelet scintigraphy and contrast venography were evaluated by two blinded observers. Only studies with blinded ag...
Solitary Fibrous Tumors of the Pleura Shown on 18F-FDG and 68Ga-DOTA-FAPI-04 PET/CT
Authors: Annan Zhang, Huiyuan Zhang, Xin Zhou, Zhongwu Li, Nan Li
Journal: Clinical Nuclear Medicine (2021)

A 52-year-old man complained of pain in the right lower chest wall for a month. Chest CT found a subpleural mass, but failed to identify the nature of the tumor. The 18F-FDG PET/CT was conducted for further diagnosis and staging, which showed the mass in the lower lobe of the right lung with mild radioactive uptake of 18F-FDG. The patient was subsequently enrolled in an ongoing clinical trial using 68Ga-DOTA-FAPI-04 (fibroblast activation protein inhibitor) PET/CT. The mass showed intensive 68Ga-DOTA-FAPI-04 uptake, which was subsequently confirmed as solitary fibrous tumors of the pleura by pathology. Our case demonstrated that the 68Ga-DOTA-FAPI-04 might have excellent tumor affinity of solitary fibrous tumors of the pleura.
Letter by Banach et al Regarding Article, "Postoperative Treatment With Carvedilol, a β-Adrenergic Blocker, Prevents Paroxysmal Atrial Fibrillation After Coronary Artery Bypass Grafting"(Letter to the Editor)
Authors: Maciej Banach, Giovanni Mariscalco, Murat Ugurlucan, Jacek Rysz
Journal: Circulation (2008)
Microcinephotography of the developing heart in neural crest-ablated chick embryos.
Authors: LLeatherbury, H EGauldin, KWaldo, M LKirby
Journal: Circulation (1990)

Microcinephotography was used to study heart development in a neural crest model of heart defects, that is, persistent truncus arteriosus, interrupted aortic arch, double outlet right ventricle, or single ventricle and tricuspid valve anomalies. These defects were created in chick embryos by ablation of premigratory neural crest destined for the aorticopulmonary and truncal septa, as well as the third and fourth aortic arch arteries. When embryogenesis reached the looped cardiac tube stage of development (Hamburger-Hamilton stage 18), 19 experimental and 15 control embryos were filmed at 100 frames per second under controlled environmental conditions. Analysis of the microcinephotography films showed the following significant distinguishing characteristics of the developing heart in the experimental embryos: altered conotruncal shape in 100%, depressed contractility and dilation of the primitive ventricle in 84%, decreased emptying of the bulbus cordis in 79%, incompetent truncal cushions in 68%, incomple...