tbuckley/cabot-search huggingface dataset:
Regulation of myocardial and vascular alpha-adrenergic receptor affinity. Effects of guanine nucleotides, cations, estrogen, and catecholamine depletion.
Authors: W SColucci, M AGimbrone, R WAlexander
Journal: Circulation Research (1984)

The threshold sensitivity of cardiovascular tissues to alpha-adrenergic stimulation is determined largely by the affinity of alpha-adrenergic receptors for agonists. To determine whether changes in alpha-adrenergic receptor affinity could contribute to the regulation of cardiac and vascular responsiveness, we used the alpha-adrenergic-selective radioligands, [3H]prazosin, [3H]-WB-4101, and [3H]rauwalscine, to study and contrast the determinants of alpha-adrenergic receptor affinity in myocardium and vascular smooth muscle from the rat. In both tissues, l-epinephrine binding to the alpha 1-adrenergic receptor describes a shallow curve suggesting more than one affinity state. Computer analysis of binding to myocardial alpha 1-receptors indicates that 15% are of high affinity (Kd = 11 nM) and 85% are of low affinity (Kd = 400 nM). Expression of high affinity sites is magnesium dependent (maximum effect, 5-10 mM), and suppressed by the guanosine 5'-triphosphate analogue Gpp(NH)p (maximum effect, 1 mM) and sod...
Modulation of Blood Pressure by Central Melanocortinergic Pathways
Authors: Jerry R. Greenfield, Jeffrey W. Miller, Julia M. Keogh, Elana Henning, Julie H. Satterwhite, Gregory S. Cameron, Beatrice Astruc, John P. Mayer, Soren Brage, Teik Choon See, David J. Lomas, Stephen O'Rahilly, I. Sadaf Farooqi
Journal: New England Journal of Medicine (2008)

Weight gain and weight loss are associated with changes in blood pressure through unknown mechanisms. Central melanocortinergic signaling is implicated in the control of energy balance and blood pressure in rodents, but there is no information regarding such an association with blood pressure in humans.We assessed blood pressure, heart rate, and urinary catecholamines in overweight or obese subjects with a loss-of-function mutation in MC4R, the gene encoding the melanocortin 4 receptor, and in equally overweight control subjects. We also examined the effects of an MC4R agonist administered for 7 days in 28 overweight or obese volunteers.The prevalence of hypertension was markedly lower in the MC4R-deficient subjects than in the control subjects (24% vs. 53%, P=0.009). After the exclusion of subjects taking antihypertensive medications, blood-pressure levels were significantly lower in MC4R-deficient subjects than in control subjects, with mean (+/-SE) systolic blood pressures of 123+/-14 mm Hg and 131+/-12 mm Hg, respectively (P=0.02), and mean diastolic blood pressures of 73+/-10 mm Hg and 79+/-7 mm Hg, respectively (P=0.03). As compared with control subjects, MC4R-deficient subjects had a lower increase in heart rate on waking (P=0.007), a lower heart rate during euglycemic hyperinsulinemia (P<0.001), and lower 24-hour urinary norepinephrine excretion (P=0.04). The maximum tolerated daily dose of 1.0 mg of the MC4R agonist led to significant increases of 9.3+/-1.9 mm Hg in systolic blood pressure and of 6.6+/-1.1 mm Hg in diastolic blood pressure (P<0.001 for both comparisons) at 24 hours, as compared with placebo. Differences in blood pressure were not explained by changes in insulin levels; there were no significant adverse events.Results of our genetic and pharmacologic studies implicate melanocortinergic signaling in the control of human blood pressure through an insulin-independent mechanism.
Digital angiographic impulse response analysis of regional myocardial perfusion. Estimation of coronary flow, flow reserve, and distribution volume by compartmental transit time measurement in a canine model.
Authors: N LEigler, HSchühlen, J SWhiting, J MPfaff, AZeiher, SGu
Journal: Circulation Research (1991)

A system impulse response function that describes the kinetics of radiographic contrast material transit through the coronary circulation was calculated from 175 selective digital angiograms of normal and stenotic arteries in 10 dogs during rest and hyperemia. The goal of the study was to determine if the flow and distribution volume characteristics of the epicardial coronary arteries and the myocardial microcirculation could be stimulated by specific mathematical compartments of a lagged normal density model impulse response function in which the flow/distribution volume ratio is the inverse of the mean transit time. The arterial compartment mean transit time correlated with flow (r = 0.75); however, the correlation was significantly improved in individual dogs (r = 0.83 +/- 0.13; p less than 0.005) and was highly dependent on the length of the conduit vessel. The microcirculation compartment mean transit time was distributed as two populations with respect to flow. There was a linear correlation during ...
Ionic bases for electrophysiological distinctions among epicardial, midmyocardial, and endocardial myocytes from the free wall of the canine left ventricle.
Authors: D WLiu, G AGintant, CAntzelevitch
Journal: Circulation Research (1993)

Recent studies from our laboratory involving syncytial preparations have delineated electrophysiological distinctions between epicardium, endocardium, and a unique population of cells in the deep subepicardial to midmyocardial layers (M region) of the canine ventricle. In the present study, we used standard microelectrode, single microelectrode switch voltage-clamp, and whole-cell patch-clamp techniques to examine transmembrane action potentials, steady-state current-voltage relations, and the 4-aminopyridine-sensitive transient outward current (Ito1) in myocytes enzymatically dissociated from discrete layers of the free wall of the canine left ventricle. Action potential characteristics of myocytes isolated from the epicardium, M region, and endocardium were very similar to those previously observed in syncytial preparations isolated from the respective regions of the ventricular wall. A prominent spike and dome was apparent in myocytes from epicardium and the M region but not in myocytes from endocardiu...
難治性冠攣縮性狭心症に対しHMG-CoA還元酵素阻害薬(スタチン)が著効した一例
Authors: Miyazawa Takuya, Sakakibara Masayoshi, Hirano Shuta, Okuno Tomonobu, Kayama Daisuke, Matsuo Harumi, Asada Atsushi, Morii Takeshi, Shimizu Yoichi
Journal: Circulation (2007)
Elevation in cytosolic free calcium concentration early in myocardial ischemia in perfused rat heart.
Authors: CSteenbergen, EMurphy, LLevy, R ELondon
Journal: Circulation Research (1987)

Changes in cytosolic free calcium concentration during myocardial ischemia were measured by 19F NMR in 5FBAPTA-loaded perfused rat hearts. The hearts were perfused with Krebs-Henseleit buffer containing 5 microM of the acetoxymethyl ester of 5FBAPTA, which was hydrolyzed by cytosolic esterases to achieve cytosolic concentrations of 5FBAPTA of 0.12 to 0.65 mM. Cytosolic free calcium concentrations were calculated as the product of the ratio of peak areas for bound and free 5FBAPTA in the NMR spectra and the dissociation constant (708 nM). The basal cytosolic calcium concentration, measured in potassium or magnesium arrested hearts, was 252 nM, and the time-average calcium concentration in beating hearts was 630 nM. Following the onset of total ischemia, there was no immediate substantial change in cytosolic calcium despite a rapid decline in creatine phosphate and ATP and a marked increase in inorganic phosphate as monitored by 31P NMR, but by 10 minutes, there was a substantial increase in free calcium co...
Structure of the freeze-fractured sarcolemma in the normal and anoxic rabbit myocardium.
Authors: J SFrank, SBeydler, MKreman, E ERau
Journal: Circulation Research (1980)

The purpose of this study was to examine the ultrastructure of the sarcolemma in the normal and severely anoxic rabbit heart with the technique of freeze-fracture. Severe anoxia and subsequent reoxygenation cause a significant decrease (31%) in intramembranous particles (IMP) in the P face of the membrane and a 25% decrease in the E face. P face IMP's are severely aggregated. The decrease in density and the redistribution of IMP's indicate a severely altered lipoprotein structure of the sarcolemma. In addition, the necks of caveolae open and the caveolae become flattened in the plane of the membrane. With reoxygenation, many rupture. Spherical projections of cytoplasmic vesicles appear in the membrane (possibly of sarcoplasmic reticulum or lysosomal origin) and also can be seen to rupture after reoxygenation. When glucose is present in the perfusate, it affords some protection against these structural defects. We propose that the fragmentation or holes in the sarcolemma reported in severe anoxia are direc...
Exercise-induced ST-segment elevation in leads V1 or aVL. A predictor of anterior myocardial ischemia and left anterior descending coronary artery disease.
Authors: R FDunn, BFreedman, D TKelly, I KBailey, AMcLaughlin
Journal: Circulation (1981)

Exercise-induced ST-segment elevation in leads V1 and/or aVL in the absence of anterior Q waves occurred in 46 of 190 patients (24%) who underwent 12-lead exercise electrocardiography with thallium-201 myocardial perfusion imaging and coronary arteriography. Significant left anterior descending coronary artery (LAD) disease was present in 38 of 46 patients (83%) with V1/aVL ST evaluation and in 72 of 144 patients (50%) without V1/aVL ST elevation (p less than 0.0005). Anterior myocardial ischemia, indicated by reversible anterior perfusion defects on thallium scanning, was present in 40 of 46 patients (87%) with V1/aVL ST elevation and in 25 of 144 patients (17%) without V1/aVL ST elevation (p less than 0.0005). Exercise ST elevation in V1/aVL was detected in 38 of 110 of the patients (35%) with LAD disease, for a specificity of 90%, and in 40 of 65 of the patients (62%) with anterior myocardial ischemia, for a specificity of 95%. We conclude that during 12-lead exercise electrocardiography, ST-segment el...
Rapid two-stage arterial switch operation. Evaluation of left ventricular systolic mechanics late after an acute pressure overload stimulus in infancy.
Authors: CBoutin, GWernovsky, S PSanders, R AJonas, A RCastaneda, S DColan
Journal: Circulation (1994)

BACKGROUNDBanding of the pulmonary artery to induce left ventricular (LV) hypertrophy followed by arterial switch operation (ASO) within 2 weeks has been performed when a primary ASO was considered high risk because of inadequate LV hypertrophy.METHODS AND RESULTSPotential adverse myocardial effects of the two-stage procedure were examined by comparing outcome in 18 patients after a rapid two-stage ASO with 33 patients after a primary ASO. Regional wall motion was assessed. Echocardiographic and noninvasive pressure data were combined to obtain LV dimension, wall thickness, mass, fractional shortening, rate-corrected mean velocity of shortening, and end-systolic wall stress. Afterload-adjusted velocity of shortening was obtained as a load-independent index of contractility. In the two-stage ASO group, the magnitude and rate of hypertrophy after pulmonary artery banding were measured serially. No wall motion abnormalities were seen in either group. Systolic dysfunction due to higher afterload and lower con...
Clinical Validation pf a Multi Target Fecal Immunochemical Test for Colorectal Cancer Screening
Authors: W de Klaver, P Wisse, F van Wifferen, L Bosch, C Jimenez, R van der Hulst, R Fijneman, E Kuipers, M Greuter, B Carvalho, M Spaander, E Dekker, V Coupé, M de Wit, G Meijer
Journal: Endoscopy (2021)

Aims The fecal immunochemical test (FIT) is widely used in colorectal cancer (CRC) screening. However, FIT leaves room for improvement, in particular for detecting advanced adenomas. To this end the present study aims to design a multi target FIT (mtFIT) to improve FIT-based screening.
Electrophysiological testing and nonsustained ventricular tachycardia. Use and limitations in patients with coronary artery disease and impaired ventricular function.
Authors: D JWilber, BOlshansky, J FMoran, P JScanlon
Journal: Circulation (1990)

Electrophysiological testing was performed in 100 consecutive patients with spontaneous asymptomatic nonsustained ventricular tachycardia, chronic coronary artery disease, and ejection fraction of less than 40%. Fifty-seven patients without inducible sustained ventricular arrhythmias were discharged on no antiarrhythmic therapy. Sustained monomorphic ventricular tachycardia was induced in 37 patients, and polymorphic ventricular tachycardia or ventricular fibrillation was induced in six patients. Of the 43 patients with inducible sustained ventricular arrhythmias, three had spontaneous cardiac arrest during serial drug testing and were excluded from further analysis. Twenty patients were discharged on drug therapy, resulting in suppression of inducible sustained ventricular arrhythmias. The remaining 20 patients with persistently inducible sustained arrhythmias were discharged on drug therapy, resulting in maximal rate slowing of the induced tachycardia. During a mean follow-up of 16.7 months, there were ...
Vasodilator therapy in acute myocardial infarction. A comparison of sodium nitroprusside and nitroglycerin.
Authors: P WArmstrong, D CWalker, J RBurton, J OParker
Journal: Circulation (1975)

Twenty-six patients with complicated acute myocardial infarction were studied in order to compare the hemodynamic effects of sodium nitroprusside (NP) and nitroglycerin (GTN). All patients received NP and 18 of the 26 also received GTN to evaluate both drugs in the same individuals. Both agents produced significant declines in mean arterial pressure, total peripheral resistance (TPR), and heart rate systolic blood pressure product. However, in the 18 patients who received both drugs GTN produced a greater fall (P less than 0.05) in pulmonary capillary wedge pressure (PCW) (25 to 15 mm Hg) than did NP (24 to 17 mm Hg) and a greater increment (P less than 0.01) in (see article) (0.98 to 1.43) than NP (0.98 to 1.16). These data confirm the potent vasodilatory effects of NP and GTN and suggest that NP has a relatively balanced effect on the arterial and venous circulation, and GTN seems to produce more potent venodilatation than arterial dilatation. These observations provide a basis for a more rational choic...
Rapid and sustained coronary artery recanalization with combined bolus injection of recombinant tissue-type plasminogen activator and monoclonal antiplatelet GPIIb/IIIa antibody in a canine preparation.
Authors: H KGold, B SColler, TYasuda, TSaito, J TFallon, J LGuerrero, R CLeinbach, A AZiskind, DCollen
Journal: Circulation (1988)

The effects of bolus injections of recombinant single-chain tissue-type plasminogen activator (rt-PA) and of F(ab')2 fragments of a murine monoclonal antibody (7E3) against the human platelet GPIIb/IIIa receptor [7E3-F(ab')2] on coronary arterial thrombolysis and reocclusion was studied in a canine preparation of coronary artery thrombosis superimposed on high-grade stenosis. Bolus intravenous injections of rt-PA at a dose of 0.45 mg/kg, repeated at 15 min intervals until reperfusion occurred (maximum of four injections) caused reperfusion in five of seven dogs within 100 min (33 +/- 15 min, mean +/- SD). Reperfusion was rapidly followed (generally within 10 min) by reocclusion and then by periods of cyclical reflow and reocclusion. A single intravenous injection of 7E3-F(ab')2 alone at 0.8 mg/kg caused reperfusion within 100 min in two of six dogs (19 and 37 min) without subsequent reocclusion. Single bolus injections of different amounts (0.1 to 0.8 mg/kg) of 7E3-F(ab')2 were then combined with bolus in...
Correlation of Myeloid Derived Suppressor Cells and Response to Standard Chemoimmunotherapy in Diffuse Large B Cell Lymphoma
Authors: David M. Foureau, Qing Zhang, Lawrence J Druhan, Ryan Jacobs, Fei Guo, Steven I Park, Danyu Sun, Edward A Copelan, Belinda Rene Avalos, Nilanjan Ghosh
Journal: Blood (2017)
The importance of education on nasal spray and eye drop technique: Results from two community-pharmacy based studies
Authors: Sophie Scheire, Els Mehuys, S. Germonpre, Philippe Gevaert, Thierry Christiaens, An De Sutter, Inge Van Tongelen, S. Demarche, T. Van Hees, C. Delaey, Lucas Van Bortel, Jean Paul Remon, Koen Boussery
Journal: Allergy (2020)
Assessment of ventricular contractile state and function in patients with univentricular heart.
Authors: TSano, MOgawa, KTaniguchi, HMatsuda, TNakajima, JArisawa, YShimazaki, SNakano, YKawashima
Journal: Circulation (1989)

To elucidate the ventricular contractile state and function in patients with univentricular heart, the ventricular volume, mass, ejection phase index, and wall stress were evaluated with biplane ventriculography and pressure measurement in 41 patients: 18 with left ventricular (LV) type (age, 6.4 +/- 6.1 years) and 23 with right ventricular (RV) type (age, 5.7 +/- 4.1 years), and data from patients with univentricular heart were compared with data from 19 normal control subjects (age, 7.2 +/- 4.3 years). Although the end-diastolic and end-systolic volumes were significantly greater in both types of univentricular heart than in the normal control group, the volumes for the LV and RV type patients did not differ from each other. The ejection fraction (EF) was depressed in both patient types of univentricular heart and was significantly (p less than 0.005) lower in the RV type than in the LV type patients (0.56 +/- 0.05 for LV type, 0.50 +/- 0.07 for RV type, and 0.64 +/- 0.03 for the control group). The ven...
Incomplete resection rate: incomplete training, imperfect measuring?
Authors: John Anderson
Journal: Endoscopy (2021)

Incomplete resection of a colonic polyp is referred to as a recurrence at subsequent endoscopic follow-up. Residual tissue may or may not be visible at the original resection. With time, the residual tissue grows, becoming more noticeable at subsequent colonoscopy. Incomplete polypectomy is a very important adverse outcome for the patient. Polyp recurrence is associated with fibrosis and tethering, increasing the difficulty and risk of subsequent removal. Several additional procedures may be necessary, with some patients referred to specialist units and occasionally for surgical intervention. This is an unnecessary inconvenience for the patient and is associated with increased health care and opportunity costs. Most importantly, during the interval between resection and surveillance, the lesion may become malignant: a missed opportunity for cancer prevention. It is possible that the original intervention stimulates growth factors as part of the mucosal healing process, accelerating malignant transformation.
Improvement in regional wall motion and left ventricular relaxation after administration of diltiazem in patients with coronary artery disease.
Authors: HDash, G LCopenhaver, SEnsminger
Journal: Circulation (1985)

To assess the effect of diltiazem on left ventricular systolic regional wall motion and diastolic function in patients with coronary artery disease (CAD), 22 patients underwent biplane left ventricular cineangiography before and after intravenous diltiazem (plasma concentration 154 +/- 12 ng/ml). Left ventricular and right ventricular pressures were measured by micromanometer-tipped catheters. Regional wall motion was assessed quantitatively with an area ejection fraction technique. Diltiazem decreased mean arterial pressure 11.5% (p less than .0001) and heart rate 6.8% (p less than .005); it increased cardiac index 8.8% (p less than .025) and global ejection fraction 9.1% (p less than .0001). However, left ventricular end-diastolic pressure increased 14.2% (p less than .001) and the left ventricular end-systolic pressure-volume (P-V) ratio decreased 8.8% (p less than .02). Diltiazem decreased the time constant of left ventricular relaxation by 14.3% (p less than .002), despite lack of change in the left ...
Sepsis-induced cholestasis
Authors: Kurt Lenz, Christine Kapral, Fritz Firlinger, Fritz Wewalka
Journal: Hepatology (2007)

Hepatic dysfunction and jaundice is a common finding in patients with septic shock. In their excellent review, Dr. Nisha Chand and Prof. Arun J. Sanyal draw attention to an early and suitable management of the underlying infection as the only effective management known yet to improve hepatic dysfunction and jaundice.1 Maintenance of normoglycemia (blood glucose level between 4.4-6.1 mmol/l) with intensive insulin therapy versus conventional insulin treatment (blood glucose level between 10.0-11.1 mmol/l) was recently shown to reduce mortality in critically ill patients.2 In a subgroup of 36 patients included in this study, liver biopsies were available. In patients with intensive insulin treatment, ultrastructural and functional abnormalities of hepatic mitochondria could be prevented or reversed.3 Therefore, strict glycemic control with normoglycemia may be an additional effective procedure to prevent and/or reduce hepatic dysfunction in patients with severe sepsis and septic shock. Kurt Lenz*, Christine Kapral*, Fritz Firlinger*, Fritz Wewalka*, * Department of Internal and Intensive Care Medicine, Hospital St. John of God, Linz, Austria.
Ischemic heart disease and platelet aggregation. The Caerphilly Collaborative Heart Disease Study.
Authors: P CElwood, SRenaud, D SSharp, A DBeswick, J RO'Brien, J WYarnell
Journal: Circulation (1991)

The Caerphilly Collaborative Heart Disease Study is based on a large cohort of men (2,398) aged 49-66 years at the time of study. Platelet aggregation induced by collagen, thrombin, and ADP was measured in fasting blood samples and was related to prevalent angina, past myocardial infarction, and electrocardiographic evidence of ischemic heart disease. A number of subjects had taken aspirin, other nonsteroidal anti-inflammatory drugs, or other drugs affecting platelet aggregation 7 days before blood sample collection; after the exclusion of these subjects, data were available for 1,811 men. No relations were demonstrated with angina, but significant relations were shown between past myocardial infarctions and electrocardiographic evidence of ischemia and ADP-induced aggregation (both primary and secondary) and between electrocardiographic evidence of ischemia and thrombin-induced aggregation. The strongest relation indicated more than a twofold increase in the odds of a past myocardial infarction in subjec...
Carotid sinus baroreceptors modulate tracheal smooth muscle tension in dogs.
Authors: H DSchultz, T EPisarri, H MColeridge, J CColeridge
Journal: Circulation Research (1987)

Arterial baroreceptors are known to influence airway smooth muscle tone. Thus, increasing carotid sinus pressure from 20 to 200 mm Hg causes reflex tracheal dilation. However, the effects of changing sinus pressure around a normal arterial pressure set-point of 100 mm Hg have not been examined. In anesthetized, artificially ventilated dogs, we distended the vascularly isolated carotid sinuses with a pulsatile pressure and recorded isometric tension in an upper tracheal segment. The aortic nerves were cut. Increasing mean carotid sinus pressure in steps between 100 and 200 mm Hg decreased tracheal tension, heart rate, and arterial blood pressure; decreasing sinus pressure between 100 and 25 mm Hg had the opposite effect. Changing carotid sinus pressure still evoked tracheal responses when systemic arterial pressure was held constant. Increasing and decreasing carotid sinus pulse pressure around a constant mean pressure evoked similar changes in tracheal tension. All reflex effects were abolished by cutting...