tbuckley/cabot-search huggingface dataset:
Effects of fibrous cap thickness on peak circumferential stress in model atherosclerotic vessels.
Authors: H MLoree, R DKamm, R GStringfellow, R TLee
Journal: Circulation Research (1992)

It is likely that factors other than stenosis severity predispose some atherosclerotic plaques to rupture. Because focal increases in circumferential stress may be an important mechanism of plaque rupture, we examined peak circumferential stress of atherosclerotic lesions by using finite element analysis based on idealized two-dimensional cross sections of diseased vessels similar to intravascular ultrasound images. The study was designed to test the hypothesis that subintimal plaque structural features such as thickness of the fibrous cap are more important factors in the distribution of stress in the plaque than stenosis severity. The analysis incorporated equilibrium biomechanical parameters from normal and diseased vessels and determined the stress distribution within the plaque at a mean luminal internal pressure of 110 mm Hg. With a constant luminal area reduction of 70%, maximum circumferential stress (sigma max) normalized to luminal pressure (sigma max/P) increased from 6.0 to 24.8 as the thickne...
Direct evidence from intraneural recordings for increased central sympathetic outflow in patients with heart failure.
Authors: W NLeimbach, B GWallin, R GVictor, P EAylward, GSundlöf, A LMark
Journal: Circulation (1986)

Patients with heart failure have increased vascular resistance and evidence for increased neurohumoral drive. High levels of circulating norepinephrine are found in patients with heart failure, but it is not known whether they reflect increased sympathetic neural activity or result from altered synthesis, release, or metabolism of norepinephrine. We used microneurography (peroneal nerve) to directly record sympathetic nerve activity to muscle (mSNA) and also measured plasma norepinephrine levels in patients with heart failure and in normal control subjects. Our goal was to determine whether sympathetic nerve activity is increased in patients with heart failure and whether plasma norepinephrine levels correlate with levels of mSNA in heart failure. Resting muscle sympathetic nerve activity in 16 patients with moderate to severe heart failure (54 +/- 5 bursts/min, mean +/- SE) was significantly higher (p less than .01) than the levels of activity in either nine age-matched normal control subjects (25 +/- 4 ...
Decline in Late Mortality after Allogeneic Blood or Marrow Transplantation (alloBMT) Performed in Childhood: a Report from the BMT Survivor Study-2 (BMTSS-2)
Authors: Anna Sallfors Holmqvist, Yanjun Chen, Jessica Wu, Lindsey Hageman, Liton F. Francisco, Mariel Parman, Michelle Kung, Emily Ness, Kevin D. Battles, Ravi Bhatia, Donna Salzman, Jeanette Falck Winther, Stephen J. Forman, Joseph Rosenthal, Daniel J. Weisdorf, Saro H. Armenian, Mukta Arora, Smita Bhatia
Journal: Blood (2017)
Effect of chronic dihydropyridine (isradipine) on the large arterial walls of spontaneously hypertensive rats.
Authors: B ILevy, MDuriez, MPhillipe, PPoitevin, J BMichel
Journal: Circulation (1994)

BACKGROUNDThe effect of genetic hypertension and of chronic therapy by calcium entry blocker (CEB, isradipine) on the function and structure of large arteries has been studied in adult spontaneously hypertensive rats (SHR, n = 30) and in their normotensive control Wistar-Kyoto (WKY) rats (n = 30).METHODS AND RESULTSFifteen-week-old rats were randomly allocated to treatment with isradipine (3 mg/kg subcutaneously once a day) or to placebo and followed for 12 weeks. Hemodynamic parameters, including instantaneous pressure and aortic velocity, were recorded under anesthesia at the end of the treatment period. Passive mechanical properties of carotid arteries were measured in situ in the presence or the absence of smooth muscle cell activity (potassium cyanide poisoning). Histomorphometric parameters of the carotid and aortic media, including cross-sectional area, medial thickness, nucleus density and size, and medial contents of proteins of interstitial matrix, were measured by an automated morphometric syst...
History of drugs for thrombotic disease. Discovery, development, and directions for the future.
Authors: R LMueller, SScheidt
Journal: Circulation (1994)

The history of the antithrombotic agents--aspirin, heparin, warfarin, and the thrombolytics--is a rich and lively odyssey of serendipity, perseverance, vision, and conflict involving a number of striking personalities. The history of aspirin spans ages and continents from Hippocrates' analgesic for women in labor to the rediscovery of the white willow bark by English country scholar Reverend Edward Stone. Bayer chemist Felix Hoffmann reinvented aspirin for his ailing father; suburban physician L.L. Craven pioneered the prophylactic antithrombotic uses of aspirin; and Sir John Vane elucidated aspirin's mechanism of action as the inhibition of prostaglandin synthetase. Heparin was discovered by McLean, working as a medical student in 1915 in search of a pure procoagulant in dog liver. His original impure material differed somewhat from today's heparin, but purified heparin was rapidly accepted for a myriad of clinical uses; to this day, diverse new properties of this complex glycosaminoglycan continue to be...
Maximal twitch tension in intact length-clamped ferret papillary muscles evoked by modified postextrasystolic potentiation.
Authors: FUrthaler, A AWalker, D NReeves, L LHefner
Journal: Circulation Research (1988)

A modified test of postextrasystolic potentiation achieved with a brief episode of rapid pacing followed by a 6-second pause (RPP maneuver) was used to evoke maximal force in isolated intact ferret right ventricular papillary muscles. Maximal RPP tensions were examined under length-clamped conditions and compared with the steady-state forces obtained when further increases in [Ca2+]o, did not further increase force and to the tensions recorded at the point of saturation of force when similarly length-clamped muscles were subjected to caffeine-induced tetanization. The results show that the calculated maximal twitch tension achieved with RPP is comparable to the 25-35 g/mm2 observed in intact single skeletal muscle fibers. The study also shows that the beat-to-beat decay of the potentiated contraction is exponential. While the amount of the constant fractional beat-to-beat decay is a function of [Ca2+]o, it is not influenced by length. During the decay of potentiation, the ratio of the potentiation of any ...
Delayed rectifier outward current and repolarization in human atrial myocytes.
Authors: ZWang, BFermini, SNattel
Journal: Circulation Research (1993)

Previous work has suggested that the primary time-dependent repolarizing current in human atrium is the transient outward current (Ito), but interventions known to alter the magnitude of the delayed rectifier current (IK) affect atrial electrophysiology and arrhythmias in humans. To explore the potential role of IK in human atrial tissue, we used the whole-cell configuration of the patch-clamp technique to record action potentials and ionic currents in isolated myocytes from human atrium. A delayed outward current was present in the majority of myocytes, activating with a time constant ranging from 348 +/- 61 msec (mean +/- SEM) at -20 mV to 129 +/- 25 msec at +60 mV. The reversal potential of tail currents was linearly related to log [K+]o with a slope of 55 mV per decade, and fully activated tail currents showed inward rectification. The potassium selectivity, kinetics, and voltage dependence were similar to those reported for IK in other cardiac preparations. In cells with both Ito and IK, IK greatly e...
The conduction system in tricuspid atresia with and without regular (d-) transposition.
Authors: SBharati, MLev
Journal: Circulation (1977)

This is a serial section examination of conduction system in six hearts with tricuspid atresia. Four had regular (d-) complete transposition and two did not have transposition. The conduction system was more or less the same in all the hearts. The atrioventricular (A-V) node was in the normal position posteriorly and was short. The A-V bundle was situated in the left ventricular aspect of the subendocardium and passed posteriorly to the ventricular septal defect. Even though this type of conduction system is abnormal in some respects, it is not the type one finds in single ventricle with small outlet chamber with regular (d-) transposition. In those hearts an anteriorly located A-V node is present. These findings further substantiate the concept that tricuspid atresia with or without transposition is not a form of single (primitive) ventricle.
Beneficial effect of physical training on blood flow to myocardium perfused by chronic collaterals in the exercising dog.
Authors: W HHeaton, K CMarr, N LCapurro, R EGoldstein, S EEpstein
Journal: Circulation (1978)

To determine the effect of physical training on collateral blood flow, we measured regional myocardial blood flow (MBF) by injecting 15 mu radioactive microspheres at rest and during exercise in 14 dogs with chronic coronary occlusive lesions. Seven dogs subsequently trained for 6 weeks while the other seven remained in kennels. Training effect was documented by decrease in heart rate during exercise that averaged 35 beats/min. MBF studies were repeated after 6 weeks. Myocardial samples were obtained from normally perfused zones (NZ) and from regions supplied via collaterals (collateral dependent zones or CZ). Initially, endocardial blood flow in CZ averaged 1.110 ml/min/g (83% of NZ, P less than 0.05) at rest and 1.36 ml/min/g (69% of NZ, P less than 0.05) during exercise, indicating relative underperfusion. Epicardial blood flow was equal in NZ and CZ. After 6 weeks MBF was not significantly changed in control animals. After training, however, MBF to underperfused endocardium of CZ during exercise was 3...
Principles of Biochemistry
Authors: W. Eugene Knox
Journal: JAMA (1964)

The third edition, coming ten years after the first, emphasizes both the flowering of biochemical research and the prodigious effort by busy teachers and scientists to keep up to date this popular text and reference. A growing number of physicians know biochemistry primarily through its pages. Despite the withdrawal of Dr. DeWitt Stetten, the remaining authors managed again to assimilate the significant advances of the past five years without increasing the size of the volume. Each author was again responsible for the whole, a procedure which gives an evenness of treatment that is rare in this day of multiauthored books. Perhaps this is also the secret for the brevity: each deletes from the other's writing. The effort will be appreciated by the readers, who are amply compensated for a spare but readable style by the handsome format, numerous formulas and illustrations, and an excellent index. The general organization has not
The association of postural changes in systolic blood pressure and mortality in persons with hypertension: the Hypertension Detection and Follow-up Program experience.
Authors: B RDavis, H GLangford, M DBlaufox, J DCurb, B FPolk, N BShulman
Journal: Circulation (1987)

Participants in the Hypertension Detection and Follow-up Program (HDFP) were classified on the basis of baseline standing minus sitting systolic blood pressure into four groups (less than or equal to -20 [group 1], -19 to 0 [group 2], 1 to 20 [group 3], and greater than 20 mm Hg [group 4]) to study 5 year mortality. Group 1, 3.3% of the total, contained those participants who had postural hypotension. The 5 year total and age-adjusted mortality rates for these groups were significantly different (p less than .04), with group 1 having the highest rates. To account for the possible confounding effects of certain baseline risk factors--age, sex, race, prior antihypertensive treatment, randomization group, diabetes, end-organ damage, sitting diastolic and systolic blood pressures, pulse, hematocrit, smoking status, and relative weight (percent of ideal weight)--in assessing group differences in mortality rates, a multiple logistic model was used. Relative weight proved to be a confounding factor for the assoc...
Identification and characterization of leukotriene C4 receptors in isolated rat renal glomeruli.
Authors: B JBallermann, R ALewis, E JCorey, K FAusten, B MBrenner
Journal: Circulation Research (1985)

The immediate reduction of renal blood flow and glomerular filtration rate in response to intravenous infusion of leukotriene C4 in the rat prompted an analysis of isolated rat renal glomeruli for the presence of specific receptors for leukotriene C4. Specific binding of [3H]leukotriene C4 to glomeruli increased in a time-dependent manner, reached equilibrium after 60 minutes of incubation at 4 degrees C, and was 80% reversible upon addition of excess unlabeled leukotriene C4 at equilibrium. Specific binding of [3H]leukotriene C4 to glomeruli increased in a dose-dependent manner, approaching saturation at concentrations of 40-60 nM. Inhibition of binding of [3H]leukotriene C4 with increasing concentrations of unlabeled leukotriene C4 was dose dependent. The equilibrium dissociation constant for [3H]leukotriene C4 binding to glomeruli, calculated from saturation and competitive binding-inhibition studies, was 25 +/- 7 nM and 35 +/- 16 nM (mean +/- SEM), respectively, and glomerular leukotriene C4 receptor ...
Gastric ESD: Preliminary Experience in a Tertiary Center in Quebec
Authors: D Maillet, E Désilets, T Manière
Journal: Endoscopy (2021)

Aims Endoscopic submucosal dissection (ESD) is a common treatment for early gastric cancer (EGC). Western countries have less experience with this challenging technique. The goal of this study is to evaluate the effectiveness of ESD as a preliminary experience.
Outcome in medically treated coronary artery disease. Ischemic events: nonfatal infarction and death.
Authors: P JHarris, K LLee, F EHarrell, V SBehar, R ARosati
Journal: Circulation (1980)

In this study we extended the characterization of outcome in 1214 medically treated patients with coronary disease by considering nonfatal infarction and death together as ischemic events. At 7 years, the cumulative event rate was 47% (18% for nonfatal infarction as the initial event and 29% for death as the initial event). In multivariable analysis of 81 baseline descriptors, 11 (six clinical and five catheterization) were independent predictors of events. Progressive chest pain, number of diseased vessels, left main stenosis and left ventricular (LV) function were the most important predictors. Progrressive pain was a more important predictor of total events than of survival alone. In patients with one-, two- or three-vessel disease and normal LV function, nonfatal infarcation accounted for at least 50% of initial events. In patients with left main disease or severe LV dysfunction, death was the predominant event. These results have important implications for interpreting the natural history of coronary...
Hypoxic contraction of isolated canine coronary artery. Mediation by potassium-dependent exocytosis of norepinephrine.
Authors: L JBorda, RShuchleib, P DHenry
Journal: Circulation Research (1980)

Effects of hypoxia on arterial tone, efflux of potassium, and efflux of norepinephrine were monitored for isolated canine coronary arteries labeled with radioactive potassium (42K) and norepinephrine (3HNE). Hypoxia elicited transient relaxation and subsequent sustained contraction accompanied by marked increases in the effluxes of 42K and 3HNE. After sympathetic nerve injury with 6-hydroxydopamine or cold storage, arteries responded to hypoxia with sustained relaxation. Sustained relaxation occurred also after pretreatment with L-propranolol, but not with D-propranolol or phentolamine. Inhibition of hypoxic contraction by L-propranolol did not alter 42K or 3HNE efflux. Colchicine, an inhibitor of the exocytosis of NE, suppressed hypoxic 3HNE efflux and contraction, but not 42K efflux. Proadifen inhibited 42K and 3HNE efflux as well as contraction. During proadifen-inhibited 42K efflux, exogenous K+ augmented overflow of 3HNE, indicating that proadifen relaxed the hypoxic artery primarily by inhibiting K+...
Renal cortical blood flow distribution in obstructive nephropathy in rats.
Authors: N JSiegel, R AFeldman, BLytton, J PHayslett, MKashgarian
Journal: Circulation Research (1977)

To examine the role of intrarenal hemodynamics in in obstructive nephropathy, we determined cortical blood flow distribution (CBFD) in rats with bilateral ureteral occlusion (BUO) and unilateral ureteral occlusion (UUO) during and after release of obstruction. Prior to release of obstruction of 24 hours' duration, we found that outer cortical perfusion decreased by 20+/-5% in both BUO and UUO rats. Furthermore, one hour after release of BUO, there was rapid normalization of CBFD associated with a modest return of glomerular filtration rate (GFR), an almost complete return of renal blood flow (RBF), and a marked postobstructive diuresis. In contrast, after release of UUO, we observed that outer cortical perfusion remained decreased by 21+/-31%, both GFR and RBF remained markedly depressed, and no diuresis occurred. These data demonstrate (1) marked ischemia of the outer cortex in both BUO and UUO during obstruction, (2) a rapid return of CBFD to a normal pattern after release of BUO, but (3) persistent out...
Determination of right atrial and right ventricular size by two-dimensional echocardiography.
Authors: WBommer, LWeinert, ANeumann, JNeef, D TMason, ADeMaria
Journal: Circulation (1979)

No data are available on determining right atrial and right ventricular size by two-dimensional echocardiography. We performed two-dimensional echocardiograms on eight human right-heart casts obtained at autopsy and on 50 patients who underwent complete left- and right-heart catheterization. Measurement of individual dimensions of the long and short axes of the right atrium and ventricle from right heart casts closely correlated with the volume of these structures as determined by water displacement. Further, individual dimensions by cross-sectional echo correlated well with actual casts dimensions. Subsequently, echocardiographic measurements of right atrial and ventricular long and short axes were obtained in the apical four-chambered view in a group of normals and compared with a group of patients with right ventricular volume overload states. Mean values for right atrial short-axis and long-axis measurements were greater in right ventricular volume overload patients than in normals: 6.5 +/- 0.3 vs 3.6...
KCNJ2‐E118Dにより引起される運動誘発性心イベント,著明なU波および洞結節機能障害を示す遺伝性不整脈症候群
Authors: Nakajima Tadashi, Kaneko Yoshiaki, Iizuka Takashi, Iijima Takafumi, Ohta Masaki, Irie Tadanobu, Kurabayashi Masahiko
Journal: Circulation (2016)
Transcapillary escape rate of albumin and right atrial pressure in chronic congestive heart failure before and after treatment.
Authors: BHesse, H HParving, HLund-Jacobsen, INoer
Journal: Circulation Research (1976)

The transcapillary escape rate of albumin (TERalb), i.e., the fraction of intravascular mass of albumin that passes to the extravascular space per unit of time, was determined from the disappearance of intravenously injected 125I-labeled human serum albumin during the first 60 minutes after injection in 10 subjects with chronic right heart failure. The investigation was repeated after sodium and water depletion. Before treatment TERalb was significantly elevated (mean 8.3 +/- 1.6% (SD)/hour, in comparison to values for normal subjects (mean 5.4 +/- 1.1%/hour, P less than 0.001). With treatment TERalb decreased significantly (mean 5.9 +/- 1.2%/hour, P less than 0.01). Right atrial pressure decreased from an average of 10 mm Hg to 6 mm Hg during treatment. A statistically significant, positive correlation was found between TERalb and right atrial pressure (r = 0.77, P less than 0.001). Our results best can be explained by increased filtration, mainly through the venous end of the microvasculature, due to th...
Direct thrombin inhibitors in cardiovascular medicine.
Authors: JLefkovits, E JTopol
Journal: Circulation (1994)

Currently used antithrombotics such as heparin have a number of potential limitations that may be overcome by the new class of agents that directly inhibit thrombin. These agents variously block the active catalytic and/or the anion binding exosites of the thrombin molecule and are potent and specific inhibitors of thrombin's many biological actions, as demonstrated by in vitro and animal models of thrombosis. Preliminary data indicate that the direct antithrombins are safe and efficacious in humans, and their use in acute coronary syndromes and coronary angioplasty in place of heparin has yielded promising early results. Phase III trials in these clinical settings are currently under way. Newer antithrombotics that inhibit thrombin generation and thrombin activity at various strategic points within the coagulation cascade are also in the early stages of development.
A positive feedback sympathetic pressor reflex during stretch of the thoracic aorta in conscious dogs.
Authors: MPagani, PPizzinelli, MBergamaschi, AMalliani
Journal: Circulation Research (1982)

The role of pressor sympathetic reflexes in circulatory control was investigated in conscious dogs. Animals were previously instrumented with a 6- to 8-cm rigid core cannula covered by an inflatable rubber cylinder in the thoracic aorta, a pressure catheter implanted in the aorta above the cannula, and a second catheter inserted into the aorta below the cannula through a femoral artery. Two piezoelectric crystals were positioned at opposing adventitial sites to measure aortic distension with ultrasound techniques. After recovery from surgery, the diameter of the aortic segment surrounding the cannula was increased by 9.6 +/- 0.4% from 16 +/- 1 mm by inflating the rubber cylinder, without obstructing blood flow. Mean aortic pressure rose 31 +/- 3% from 100 +/- 3 mm Hg and heart rate 20 +/- 3% from 91 +/- 3 beats/min (P less than 0.01). The pressor response was abolished by alpha-adrenergic blockade (phentolamine 1 mg/kg, iv). The heart rate response was reduced either by beta-blockade (propranolol 1 mg/kg,...
Abstract 16875: Mortality Rates Among Patients With Venous Thromboembolism on Anticoagulant Therapy
Authors: EdithNutescu, XueSong, BrahimBookhart, NianwenShi, MonikaRaut, C VDamaraju, JeffSchein, ScottKaatz
Journal: Circulation (2014)

Background: Venous thromboembolism (VTE), comprising deep vein thrombosis (DVT) and pulmonary embolism (PE), is associated with significant morbidity and mortality. The prognosis for patients who develop DVT or PE is directly related to the risk of recurrent events and other complications, such as bleeding. These complications, along with patient-specific factors, may result in additional mortality risk. Objectives: To determine the rate of all-cause mortality during follow-up based on the type (cancer provoked, surgery/pregnancy/oral contraception-provoked, or unprovoked) of DVT and PE. Methods: A large US claims database was used to identify patients who had DVT or PE, ≥1 anticoagulant prescription, and were linked to the Social Security Administration file from 7/1/2006 to 7/31/2013. All patients were ≥18 years old, had continuous database enrollment and no VTE or anticoagulant use in the 6 months preceding the index diagnosis of VTE. All patients were followed until death or end of study. Bleeding and...