tbuckley/cabot-search huggingface dataset:
Comparative antioxidant activities of propranolol, nifedipine, verapamil, and diltiazem against sarcolemmal membrane lipid peroxidation.
Authors: I TMak, W BWeglicki
Journal: Circulation Research (1990)

The antiperoxidative activities of nifedipine, verapamil, and diltiazem were compared with that of propranolol by using an in vitro model of sarcolemmal membrane lipid peroxidation. Highly purified sarcolemmal membranes, isolated from canine ventricular myocytes, were peroxidized by a superoxide anion-producing and iron-catalyzed free radical-generating system (dihydroxy-fumarate plus FeCl3 and ADP). Lipid peroxidation after 20 minutes of incubation was monitored by malondialdehyde formation. Similar to propranolol, all three calcium blockers exhibited concentration-dependent (10-400 microM) inhibitory effects against sarcolemmal lipid peroxidation. The order of potency of these agents was nifedipine greater than propranolol greater than verapamil greater than diltiazem. Nifedipine, the most effective calcium blocker, was greater than twofold more potent than propranolol and achieved a significant effect at 10 microM. This study suggests that calcium blockers may provide antiperoxidative protection to car...
Renal and hemodynamic effects of intravenous fenoldopam versus nitroprusside in severe hypertension.
Authors: W JElliott, R RWeber, K SNelson, C MOliner, M TFumo, D DGretler, G RMcCray, M BMurphy
Journal: Circulation (1990)

The renal and hemodynamic effects of intravenously administered fenoldopam mesylate, a novel dopamine-1 receptor agonist, were compared with those of sodium nitroprusside in 28 patients (18 male; 26 black, two white; average age, 49 +/- 3 years) with an average blood pressure of 219/137 mm Hg, most of whom presented with acute target organ damage. Fenoldopam and nitroprusside lowered blood pressure safely to an average pressure of 176/105 mm Hg; highly significant dose-response relations were found for the 13 patients receiving fenoldopam and the 15 receiving nitroprusside. Volume and sodium, potassium, and creatinine concentrations were measured in freely voided urine specimens both before and during intravenous therapy. In the fenoldopam-treated patients, there were significant increases in urinary flow (92 +/- 21 to 168 +/- 37 ml/hr, p less than 0.003), sodium excretion (227 +/- 73 to 335 +/- 90 mu eq/min, p less than 0.001), and creatinine clearance (70 +/- 11 to 93 +/- 13 ml/hr, p less than 0.003). I...
Mechanical deformation of vessel wall and shear stress determine the basal release of endothelium-derived relaxing factor in the intact rabbit coronary vascular bed.
Authors: DLamontagne, UPohl, RBusse
Journal: Circulation Research (1992)

We investigated the mechanisms that are responsible for the basal release of endothelium-derived relaxing factor (EDRF), which is likely to be identical with nitric oxide, in the intact coronary circulation. The increase in cGMP content of platelets passing through the coronary bed of the isolated rabbit heart was used as an index of EDRF release. Platelet cGMP content after passage through the heart under control conditions (flow rate of 20 ml/min) amounted to 0.50 +/- 0.10 pmol/mg protein. Inhibition of endothelial nitric oxide synthesis by 30 microM NG-nitro-L-arginine (L-NNA) reduced this amount by more than 60%. Increasing flow rate from 20 ml/min to 40 and 60 ml/min led to flow-dependent dilation as reflected by the subsequent drop in perfusion pressure after an initial rise. The flow-dependent dilation was associated with a significant increase in the normalized platelet cGMP content. L-NNA abolished completely both the flow-dependent dilation and the increase in platelet cGMP content. Increasing s...
The angiotensin II pressor system of the rat forebrain.
Authors: D KHartle, M JBrody
Journal: Circulation Research (1984)

An anterior hypothalamic knife cut that leaves intact two central sites of action of angiotension II produces the same deficits in the pressor responses to angiotensin II that have been attributed to destruction of two circumventricular organs (the subfornical organ and the organum vasculosum of the lamina terminalis). The central pressor actions of angiotensin II are necessary for the full expression of renin-dependent renal hypertension. The anterior hypothalamic knife cut attenuates renin-dependent aortic ligation hypertension. It has been shown that electrolytic destruction more anterior to this knife cut, in the anteroventral 3rd ventricle region, also attenuates two forms of renin-dependent hypertension, aortic ligation hypertension and two-kidney Goldblatt hypertension in the rat. Electrolytic lesions in the subfornical organ also reduce renin-dependent, two-kidney Goldblatt hypertension. These data are consistent with the hypothesis that a common efferent system from the organum vasculosum of the ...
Prognostic Scores In Post-Endoscopic Retrograde Cholangiopancreatography Acute Pancreatitis: Is There A Better Option?
Authors: V Macedo Silva, M Freitas, R Sousa Magalhães, T Cúrdia Gonçalves, P Boal Carvalho, B Rosa, J Cotter
Journal: Endoscopy (2021)

Aims Acute pancreatitis (AP) is the most commonly observed complication after endoscopic retrograde cholangiopancreatography (ERCP). Precocious risk stratification is crucial in the management of these patients, in order to avoid adverse outcomes. Multiple prognostic scores are already commonly used in AP, regardless of its etiology. Scarce data is available upon their use specifically on post-ERCP AP. We aimed to compare the acuity of different prognostic scores at post-ERCP AP diagnosis for prediction of a moderate to severe course.
Evaluation Of Colorectal Polypectomy Practices In Portugal – A Nationwide Survey From A Western Europe Country
Authors: E Dantas, M Coelho, C Sequeira, I Santos, G Simões, P Currais, C Félix, A Laranjo, T Gago, J Roseira, C Gouveia, D Reis, G Alexandrino, C Leal, R Morais, M Flor de Lima, F Pereira, T Guedes, V Magno Pereira, JC Silva, F Taveira, M Bento-Miranda, D Libânio, M Brito, P Antunes, F Pires, C Cardoso, I Cremers, AP Oliveira
Journal: Endoscopy (2021)

Aims Colonoscopy allows identification and removal of premalignant polyps. With this study, we aimed to assess the current polypectomy practice patterns among Portuguese endoscopists and verify if they followed the European guidelines for colorectal polypectomy.
Prevention of lipid accumulation in experimental vein bypass grafts by antiplatelet therapy.
Authors: L IBonchek, L EBoerboom, G NOlinger, J RPepper, JMunns, LHutchinson, A HKissebah
Journal: Circulation (1982)

The ameliorative effect of antiplatelet therapy on atherogenesis of vein grafts was assessed in autologous cephalic veins grafted into femoral arteries of 16 normolipemic and 11 hyperlipemic stump-tailed macaque monkeys. Before grafting, one half of each vein was distended at high pressure (700 mm Hg) and the other half at low pressure (350 mm Hg). Eight normolipemic monkeys were treated with aspirin, 80 mg/day, and dipyridamole, 50 mg/day, and eight were controls. When grafts were harvested at 12 weeks, tissue cholesterol and beta-apoprotein content in grafts from untreated monkeys were significantly higher than in ungrafted, uninjured veins. Antiplatelet therapy eliminated the increase in lipid content of vein segments distended at low pressure, and significantly lowered lipid content of segments distended at high pressure, though not to be control levels of ungrafted veins. Seven of the 11 hyperlipemic monkeys received antiplatelet drugs and four did not. The lipid content of all graft segments was sig...
Prognostic efficacy of early clinical categorization of myocardial infarction patients.
Authors: M WPozen, J KStechmiller, G CVoigt
Journal: Circulation (1977)

To assess the prognostic validity of low  classification at 24-36 hours as the basis for early transfer to an intermediate coronary care unit, Killip and Hutter/Sidel criteria for risk classicication were applied to 410 patients with acute myocardial infarction (MI) and prospectively compared with respect to mortality and morbidity. Six percent of low  patients by the Killip classification subsequently died and were therefore misclassified. No patients in the group classified as low  by the Hutter/Sidel criteria died; however, more than two and a half times as many potentially low  patients were excluded from this group. With respect to morbidity, 35 of 87 patients (40%) classified as low  by Hutter/Sidel criteria developed 43 major complications during their hospitalization. Nine of these patients developed 11 of the 43 complications (26%) on day six or later, and for five of these patients, this was their first major complication during hospitalization. This significant inc...
Vasodilatory effects of C-type natriuretic peptide on forearm resistance vessels are distinct from those of atrial natriuretic peptide in chronic heart failure.
Authors: MNakamura, NArakawa, HYoshida, SMakita, KHiramori
Journal: Circulation (1994)

BACKGROUNDC-type natriuretic peptide (CNP) is a newly identified peptide that is structurally related to atrial natriuretic peptide (ANP). Although it has been suggested that CNP is released from the endothelium for the regulation of local vascular tone, no data are available concerning the vasodilatory response to CNP in humans.METHODS AND RESULTSStrain-gauge plethysmography was used to determine the vasodilatory effects of intra-arterially infused CNP compared with the effects of ANP infusion in 11 patients with chronic heart failure (CHF) and 11 age-matched healthy controls. Graded doses of CNP and ANP (8, 16, 32, and 48 pmol.min-1.dL-1 tissue volume) were administered randomly into the nondominant brachial artery, and forearm blood flow (FBF) was measured. No significant changes in systemic blood pressure and heart rate were found during the study. Both the absolute and percent FBF responses to ANP relative to the baseline value were significantly lower in CHF patients than in healthy controls (P < .0...
Atrioventricular block in posterior acute myocardial infarction: a clinicopathologic correlation.
Authors: F JBilbao, I EZabalza, J RVilanova, JFroufe
Journal: Circulation (1987)

The specialized conducting systems of 44 hearts with posterior-inferior acute myocardial infarction were studied to clarify the anatomic basis of atrioventricular (AV) block. The results showed a lack of correlation between the block and the lesional pathology of the specialized conducting system. On the other hand, an evaluation of the atrial prenodal myocardium revealed strong clinicopathologic correlation between the block and the necrotic damage to these fibers. Twenty-nine or 97% of patients with AV block showed acute necrosis of the prenodal atrial myocardium. Considering the conducting prenodal septal atrial myocardium as a suprahisian structure, the necrosis at this level would provide an anatomic basis of the block in posterior-inferior acute myocardial infarction. Analysis of the behavior of the AV block after pharmacologic treatment further established a relationship between the block and acute lesions in the central conduction system.
Restoration of normal coronary hemodynamics and myocardial metabolism after percutaneous transluminal coronary angioplasty.
Authors: D OWilliams, R SRiley, A KSingh, A SMost
Journal: Circulation (1980)

Regional coronary blood flow and myocardial metabolism were evaluated in a patient who underwent percutaneous transluminal coronary angioplasty (PTCA). Angioplasty increased coronary luminal diameter and reduced trans-stenotic gradient. Before PTCA, angina pectoris developed during sustained rapid atrial pacing and was associated with abnormal lactate metabolism and a mild increase in coronary flow and myocardial oxygen consumption. After PTCA, angina was absent during pacing and lactate extraction was preserved. Coronary flow and oxygen consumption were increased to a greater degree than before PTCA. The temporal response of changes in coronary blood flow due to an abrupt increase in heart rate was also evaluated. Floow reached peak value more rapidly after PTCA. These observations suggest that PTCA may result in improved regional coronary blood flow and restoration of normal flow regulatory mechanism and myocardial metabolism.
Cardiac, skeletal and ophthalmologic abnormalities in relatives of patients with the Marfan syndrome.
Authors: M NPayvandi, R EKerber, C DPhelps, G FJudisch, GEl-Khoury, H GSchrott
Journal: Circulation (1977)

Nine patients with the Marfan syndrome and 40 of their first degree relatives were evaluated for the presence of cardiac, skeletal and ophthalmologic abnormalities. Aortic root dilatation and mitral valve prolapse were sought by echocardiography, and the metacarpal index was calculated from hand X-rays. Abnormalities of all the tests performed were present in all nine index cases, except for one normal eye exam. Mitral prolapse was present in thirteen relatives (33%) and aortic root dilatation in seven (18%). At least one cardiac abnormality was present in nineteen (47%) relatives. Aortic root dilatation was more common in male relatives; the incidence of mitral prolapse was approximately equal in the two sexes. Abnormal metacarpal index (greater than 8.0) occurred in fifteen of twenty-six relatives examined (58%). Ophthalmologic abnormalities were found in only four relatives. Two relatives had abnormalities of all three organ systems evaluated, five others had abnormalities of two systems, and fourteen ...
Depressed function of a ouabain-sensitive sodium-potassium pump in blood vessels from renal hypertensive dogs.
Authors: H WOverbeck, M BPamnani, TAkera, T MBrody, F JHaddy
Journal: Circulation Research (1976)

Vasodilator responses to acute intra-arterial infusions of K+ are attenuated in dogs with chronic one-kidney perinephritic hypertension in rats with chronic two-kidney Goldblatt hypertension, and in men with essential hypertension. There is evidence that K+ evokes vasodilation by stimulating vascular smooth muscle membrane Na+-K+-activated adenosine triphosphatase, thereby increasing activity of the cellular Na+-K+ electrogenic pump. We therefore proposed that there may be an underlying decrease in the operation of this pump in vascular smooth muscle of hypertensives. The operation of the cellular Na+-K+ pump may be estimated by measurement of rubidium uptake. Thus, so further investigate our hypothesis, we measured 86Rb uptake in small mesenteric arteries and splanchnic veins from 12 dogs with chronic uncomplicated one-kidney perinephritic hypertension and from 12 normotensive control dogs. Vessels were excised under thiamylal anesthesia and incubated in cold medium (plasma or Krebs-Henseleit solution) f...
Influence of beta-adrenergic stimulation and contraction frequency on rat heart interstitial adenosine.
Authors: R AFenton, STsimikas, J GDobson
Journal: Circulation Research (1990)

Adenosine (ADO) has an antiadrenergic action in the heart that causes an attenuation of contractile and metabolic responses elicited by beta-adrenergic stimulation. The effect of an increase in oxygen consumption elicited by either beta-adrenergic stimulation or an increase in contraction frequency on interstitial fluid and coronary effluent ADO levels was investigated in isolated perfused isovolumically contracting rat hearts. ADO in left ventricular surface transudates and coronary effluents was rendered fluorescent with chloroacetaldehyde, and the formed ethenoadenosine derivative was quantitated with high-performance liquid chromatography fluorescence detection. Heart preparation integrity was verified by determining the activities of lactate dehydrogenase and ADO deaminase in the transudates. Isoproterenol (10(-8) M) elicited a 45% increase in oxygen consumption and a 54% increase in developed left ventricular pressure in hearts paced at 240 beats/min. With isoproterenol the control transudate ADO co...
Noninvasive assessment of left ventricular function from the mitral valve echogram. Relation of final anterior mitral leaflet closing velocity to peak dp/dt and aortic velocity.
Authors: B IJugdutt, S JLee, DMcFarlane
Journal: Circulation (1978)

Since final mitral valve (MV) closure and aortic ejection velocity are mediated by the same forces in early left ventricular (LV) contraction, the rate of final MV closure (BC slope) should reflect LV performance. We first verified whether peak final closing velocity (ds/dt) of the anterior MV leaflet (AMVL) is related to peak aortic ejection velocity (V) and LV dp/dt in 18 open-chest dogs. We then checked the validity of the relations in man. Our approach was to measure peak ds/dt, peak aortic acceleration (dV/dt) and peak LV dp/dt using electronic differentiation of analog signals of the AMVL echogram, V and LV pressure. In dogs, resting ds/dt averaged 26.9 +/- 9.0 (SD) cm/sec and changed significantly (P less than 0.001) after isoproterenol, propranolol, coronary ligation and aortic cross-clamping. We found good (P less than 0.001) correlations between ds/dt and V (r = 0.82), dV/dt ( r = 0.67) and dp/dt (r = 0.73). In man, resting ds/dt averaged 25.5 +/- 1.6 cm/sec in six normals. In 40 patients with c...
Mechanisms of closure of cardiac sodium channels in rabbit ventricular myocytes: single-channel analysis.
Authors: A OGrant, C FStarmer
Journal: Circulation Research (1987)

We have examined the kinetics of closure of sodium channels using single-channel recordings in cell-attached and excised membrane patches of rabbit ventricular myocytes. Sodium-channel closure was dependent on membrane potential. The closing rate initially decreased with depolarization. The rate then passed through a minimum and increased at strongly depolarized potentials. We attempted to determine the separate voltage dependence of the deactivation and inactivation rate constants using the method of Aldrich, Corey, and Stevens. In a majority of experiments, the method did not give internally consistent results. As an alternative approach, batrachotoxin was used to remove inactivation and determine the voltage dependence of deactivation rate. The deactivation rate decreased with depolarization. To account for the increase in the closing rate at strongly depolarized test potentials, one must postulate voltage dependence of inactivation. The ensemble average current relaxed with a time course that was usua...
Comprehensive strategy of conduit guidance combined with VEGF producing Schwann cells accelerates peripheral nerve repair
Authors: Ping Wu, Zan Tong, Lihua Luo, Yanan Zhao, Feixiang Chen, Yinping Li, Céline Huselstein, Qifa Ye, Qingsong Ye, Yun Chen
Journal: Bioactive Materials (2021)

Peripheral nerve regeneration requires stepwise and well-organized establishment of microenvironment. Since local delivery of VEGF-A in peripheral nerve repair is expected to promote angiogenesis in the microenvironment and Schwann cells (SCs) play critical role in nerve repair, combination of VEGF and Schwann cells may lead to efficient peripheral nerve regeneration. VEGF-A overexpressing Schwann cells were established and loaded into the inner wall of hydroxyethyl cellulose/soy protein isolate/polyaniline sponge (HSPS) conduits. When HSPS is mechanically distorted, it still has high durability of strain strength, thus, can accommodate unexpected strain of nerve tissues in motion. A 10 mm nerve defect rat model was used to test the repair performance of the HSPS-SC (VEGF) conduits, meanwhile the HSPS, HSPS-SC, HSPS-VEGF conduits and autografts were worked as controls. The immunofluorescent co-staining of GFP/VEGF-A, Ki67 and MBP showed that the VEGF-A overexpressing Schwann cells could promote the proliferation, migration and differentiation of Schwann cells as the VEGF-A was secreted from the VEGF-A overexpressing Schwann cells. The nerve repair performance of the multifunctional and flexible conduits was examined though rat behavioristics, electrophysiology, nerve innervation to gastrocnemius muscle (GM), toluidine blue (TB) staining, transmission electron microscopy (TEM) and NF200/S100 double staining in the regenerated nerve. The results displayed that the effects on the repair of peripheral nerves in HSPS-SC (VEGF) group was the best among the conduits groups and closed to autografts. HSPS-SC (VEGF) group exhibited notably increased CD31+ endothelial cells and activation of VEGFR2/ERK signaling pathway in the regenerated nerve tissues, which probably contributed to the improved nerve regeneration. Altogether, the comprehensive strategy including VEGF overexpressing Schwann cells-mediated and HSPS conduit-guided peripheral nerve repair provides a new avenue for nerve tissue engineering.
Reversible induction of right ventricular atriopeptin synthesis in hypertrophy due to hypoxia.
Authors: P TStockmann, D HWill, S DSides, S RBrunnert, G DWilner, K MLeahy, R CWiegand, PNeedleman
Journal: Circulation Research (1988)

Right ventricular hypertrophy produced in rats exposed to 10% oxygen for 3 weeks resulted in a ninefold increase in atriopeptin immunoreactivity (APir) and a 160-fold increase in atriopeptin messenger RNA (AP mRNA) in the right ventricular myocardium. A small but significant increase in left ventricular APir and AP mRNA was also present, probably representing the interventricular septum. Right atrial APir was decreased by 50%, but left atrial APir was not different from normoxic controls. Purification of ventricular tissue extracts by high-performance liquid chromatography revealed primarily the high molecular weight prohormone. The development of right ventricular hypertrophy and right ventricular APir content followed a similar time course, each evident at 7 days of hypoxia and reaching a plateau at 14 days. Hypoxia followed by normoxia caused right ventricular APir to fall to control levels within 3 days, despite persistent right ventricular hypertrophy. This data demonstrates that hypoxia can reversib...
Abstract 19027: Influence of Intravenous Ferric Carboxymaltose on Health-Related Quality of Life Measures in Patients with Chronic Heart Failure and Iron Deficiency: an Analysis from the FAIR-HF Study
Authors: Josep Comin-Colet, Mitja Lainscak, Kenneth Dickstein, Gerasimos Filippatos, Patrick Johnson, Thomas Luscher, Claudio Mori, Ronnie Willenheimer, Piotr Ponikowski, Stefan D Anker
Journal: Circulation (2010)

Background: Patients with chronic heart failure (CHF) show impaired health-related quality of life (HRQoL), which is an important target for therapeutic intervention. Impaired iron homeostasis may ...
Effect Of Clip Closure On Outcomes After Resection Of Large Serrated Polyps: Results From A Randomized Trial
Authors: SD Crockett, M Khashab, DK Rex, IS Grimm, JM Levenick, MT Moyer, H Pohl
Journal: Endoscopy (2021)

Aims Sessile serrated lesions (SSL) are most commonly located in the proximal colon, where post-polypectomy bleeding rates are higher. There is limited clinical trial evidence to guide best practices for resection of large serrated polyps (LSP), and whether clip closure of the resection defect is beneficial.
Effectiveness and Tolerability of Very Low Volume (Pleinvue) PreparatiÓn for Colonoscopy in the Elderly. Result Of a Prospective Study
Authors: S Rodriguez Muñoz, C Esteban Fernandez-Zarza, B Arberas Diez, A Ibañez Pinto, C Martinez-Alcalá García, A Lanas Gimeno
Journal: Endoscopy (2021)

Aims The use of colonoscopy in the elderly is increasing. However, the indication is debatable, in this population can prevent the morbidity and mortality of late colorectal cancer. Colonoscopy it has been considered challenging because of the difficulty in preparing this population.