tbuckley/cabot-search huggingface dataset:
8-Methoxypsoralen and longwave ultraviolet irradiation are a novel antiproliferative combination for vascular smooth muscle.
Authors: K LMarch, B LPatton, R LWilensky, D RHathaway
Journal: Circulation (1993)

BACKGROUNDSmooth muscle cell proliferation plays a major role in the genesis of restenosis after angioplasty or vascular injury. Although the effects of arterial exposure to high-energy radiation sources such as laser have been investigated in detail, the effects on vascular cells of low-intensity radiant energy in combination with photoactive agents have not been extensively characterized. Psoralens are photoactive agents that are known to be well tolerated when used in conjunction with local exposure to ultraviolet light in the A band (UVA) for the treatment of various dermatologic proliferative disorders.METHODS AND RESULTSWe have investigated the effects of psoralen/UVA (PUVA) exposure on the proliferation of bovine aortic smooth muscle cells. Proliferation and viability were assessed over a 14-day period by trypan blue exclusion counts. Cell cycle effects were evaluated by thymidine incorporation and flow cytometry with DNA quantitation after addition of serum or platelet-derived growth factor B-chai...
Sympathetic nervous system-dependent vasoconstriction in humans. Evidence for mechanistic role of endogenous purine compounds.
Authors: STaddei, RPedrinelli, ASalvetti
Journal: Circulation (1990)

Purine compounds modulate sympathetic neurotransmission; this modulation decreases nervous discharge by stimulating presynaptic inhibitory adenosine receptors, an effect antagonized by theophylline, and causes vasoconstriction through the stimulation of postsynaptic ATP receptors. In humans we evaluated the effect of local theophylline, which was infused into the brachial artery at the rate of 100 micrograms/100 cc/min, on the arteriolar sympathetic vasoconstriction induced by applying a lower-body negative pressure. Forearm blood flow changes were measured by strain-gauge venous plethysmography. Theophylline, which at this dosage blunted the vasodilator effect of adenosine (the physiological agonist for the P1 purinoceptor), significantly increased lower-body negative pressure-mediated vasoconstriction. To evaluate whether neurotransmitters different from norepinephrine participate in the vasoconstrictor effect of theophylline, we repeated the previous experiment in the presence of phenoxybenzamine, whic...
Quantification and validation of left ventricular wall thickening by a three-dimensional volume element magnetic resonance imaging approach.
Authors: RBeyar, E PShapiro, W LGraves, W JRogers, W HGuier, G ACarey, R LSoulen, E AZerhouni, M LWeisfeldt, J LWeiss
Journal: Circulation (1990)

We have developed a method to quantify and map regional wall thickening throughout the left ventricle (LV) with magnetic resonance imaging. In contrast to methods that measure planar wall thickness and thickening, this method uses the three-dimensional (3D) geometry of the left ventricle to calculate the perpendicular thickness of the wall. We tested this method at three levels of increasing complexity using 1) phantom studies, 2) in vivo experiments in dogs with normal cardiac function, and 3) in vivo studies in dogs during acute ischemia. Experiments were conducted in 15 open-chest dogs imaged by a 0.38 T iron core magnet. Five short-axis images at end diastole and end systole were obtained with the spin echo technique by use of the QRS as a trigger for end diastole and the second heart sound, S2, to time end systole. After acquisition of preischemic images, acute ischemia was induced by either coronary artery ligation (n = 5) or intracoronary dental rubber injection (n = 5), which produced severe trans...
Effect of carotid occlusion and of perfusion pressure on renal function in conscious dogs.
Authors: RGross, HKirchheim, KRuffmann
Journal: Circulation Research (1981)

We studied the effect of bilateral common carotid occlusion (implanted pneumatic cuffs) on renal blood flow (electromagnetic flowmeter) and renal function (implanted ureteral catheter) in nine chronically instrumented, conscious dogs on a high sodium diet (14 mmol/kg body weight per day). By means of suprarenal aortic constriction (pneumatic cuff) the influence of renal perfusion pressure was investigated. There was no change in renal blood flow or glomerular filtration rate (inulin clearance) with either reflexly increasing (+49.6%) or constant renal perfusion pressure. Carotid occlusion caused an increase of urine output by 80.5% and of sodium excretion by 85.3% due to a fall in fractional sodium reabsorption (-0.9%) when renal perfusion pressure was allowed to rise. Neither an increase of diuresis or sodium excretion nor an antinatriuresis was observed when renal perfusion pressure was kept constant during carotid occlusion. We conclude that, in conscious dogs at rest, the moderate sympathetic activati...
Combination therapy with diltiazem and nifedipine in patients with effort angina pectoris.
Authors: NToyosaki, TToyo-oka, TNatsume, TKatsuki, TTateishi, TYaginuma, SHosoda
Journal: Circulation (1988)

The antianginal effects of diltiazem and nifedipine alone and in combination were evaluated in a double-blind, randomized, placebo-controlled trial in 11 patients (nine men and two women, 57 +/- 8 years old) with stable effort angina. Each patient received placebo, 30 mg of diltiazem, 10 mg of nifedipine, and 30 mg of diltiazem plus 10 mg of nifedipine four times daily for 1 week each. Antianginal efficacy was assessed by means of a treadmill exercise test. The exercise tolerance time was significantly prolonged from 235.1 +/- 52 (placebo period) to 342.2 +/- 101 sec by diltiazem (p less than .01) and to 325.6 +/- 73 sec by nifedipine (p less than .01). The drug combination further prolonged exercise time to 451.1 +/- 103 sec, which was significantly longer than the interval attained with either diltiazem (p less than .01) or nifedipine (p less than .01) alone. The plasma concentration of diltiazem was unaffected by the addition of nifedipine, whereas the plasma nifedipine concentration was significantly ...
Body Iron Stores and Dietary Iron Intake in Relation to Diabetes in Adults in North China
Authors: De Chun Luan, Hui Li, Sui Jing Li, Zhuo Zhao, Xin Li, Zhong Mei Liu
Journal: Diabetes Care (2008)

In response to the letter of Shi and Pan (1), we appreciate their interest and willingness to comment on our study (2). First, it does not matter whether the lowest quartile (featuring very low levels of heme iron intake) or higher quartiles are chosen as the reference group because odds ratio is a relative value. In addition, the large range of heme iron intake in the Chinese population is …
Elevated endothelin-1 in heart failure and loss of normal response to postural change.
Authors: D JStewart, PCernacek, K BCostello, J LRouleau
Journal: Circulation (1992)

BACKGROUNDThe possible contribution of endothelin-1, a potent endothelium-derived vasoconstrictor peptide, to neurohumoral compensation for hemodynamic stress was examined in nine normal volunteers and six patients with severe congestive heart failure.METHODS AND RESULTSPlasma levels of endothelin-1 were measured with a sensitive and specific radioimmunoassay. Venous blood samples were obtained after 90 minutes of supine rest and serially during 30 minutes of 60 degrees upright tilt. Endothelin-1 levels were compared with those of known neurohumoral mediators of compensation. In normal subjects, the resting levels of endothelin-1 were low (0.74 +/- 0.11 pg/ml), and there was a rapid increase to 1.37 +/- 0.07 pg/ml at 5 minutes of upright tilting (p less than 0.05). This increase was not sustained at 10 and 15 minutes of tilt, but there was a trend toward a second rise at 30 minutes (1.14 +/- 0.17 pg/ml; p = 0.06). This biphasic pattern of response was shared by dopamine and reflected the response of syste...
Phenytoin reduces calcium current in the cardiac Purkinje fiber.
Authors: TScheuer, R SKass
Journal: Circulation Research (1983)

We have investigated the effects of phenytoin on the electrical and mechanical activity of isolated calf and dog cardiac Purkinje fibers. Phenytoin (5-100 microM) lowers and shortens the plateau phase of the Purkinje fiber action potential and reduces twitch tension. We studied the ionic basis of these effects by combining a conventional two-microelectrode voltage clamp procedure with pharmacological techniques that allow separation of time-dependent plateau membrane currents. We find that phenytoin reduces voltage-dependent calcium current in the Purkinje fiber. In addition, this drug slightly reduces two time-dependent outward currents. These effects of phenytoin on membrane current account, at least in part, for its influence on the action potential and twitch tension.
Hypertension and Prohypertensive Antineoplastic Therapies in Cancer Patients
Authors: Daan C.H. van Dorst, Stephen J.H. Dobbin, Karla B. Neves, Joerg Herrmann, Sandra M. Herrmann, Jorie Versmissen, Ron H.J. Mathijssen, A.H. Jan Danser, Ninian N. Lang
Journal: Circulation Research (2021)

The development of a wide range of novel antineoplastic therapies has improved the prognosis for patients with a wide range of malignancies, which has increased the number of cancer survivors substantially. Despite the oncological benefit, cancer survivors are exposed to short- and long-term adverse cardiovascular toxicities associated with anticancer therapies. Systemic hypertension, the most common comorbidity among cancer patients, is a major contributor to the increased risk for developing these adverse cardiovascular events. Cancer and hypertension have common risk factors, have overlapping pathophysiological mechanisms and hypertension may also be a risk factor for some tumor types. Many cancer therapies have prohypertensive effects. Although some of the mechanisms by which these antineoplastic agents lead to hypertension have been characterized, further preclinical and clinical studies are required to investigate the exact pathophysiology and the optimal management of hypertension associated with anticancer therapy. In this way, monitoring and management of hypertension before, during, and after cancer treatment can be improved to minimize cardiovascular risks. This is vital to optimize cardiovascular health in patients with cancer and survivors, and to ensure that advances in terms of cancer survivorship do not come at the expense of increased cardiovascular toxicities.
Enhancement of the force-frequency effect on myocardial contractility by adrenergic stimulation in conscious dogs.
Authors: MKambayashi, TMiura, B HOh, H ARockman, KMurata, JRoss
Journal: Circulation (1992)

BACKGROUNDThe influence of changes in heart rate on myocardial contractility (the force-frequency effect) differs under various experimental conditions, including the anesthetized versus the conscious state.METHODS AND RESULTSTo assess the influence of beta-adrenergic stimulation on force-frequency effects on myocardial contraction and relaxation, seven instrumented conscious dogs were studied in which heart rate could be controlled by atrial pacing after the intrinsic rate was slowed with a bradycardiac agent (UL-FS 49 0.5-0.75 mg/kg). Left ventricular (LV) pressure was measured with a micromanometer under resting conditions and during dobutamine infusion at low, intermediate, and high doses (2.7, 5.4, and 10.7 micrograms/kg/min). At each dose, heart rate was progressively increased from 100 to 210 beats per minute. In the absence of dobutamine (control), no significant positive force-frequency effect was detected on LV dP/dtmax; this was probably due to the known effect of the observed decrease in prelo...
Regional end-systolic pressure-length relationships using a volume-loading technique in the intact pig heart.
Authors: W PMiller, A JLiedtke, S HNellis
Journal: Circulation Research (1984)

The purpose of this study was to characterize left ventricular systolic elastances as derived from pressure-segment length and pressure-diameter relationships, and to compare the resulting regional and global elastances to known changes in inotropy. Left ventricular pressure-segment length and pressure-diameter were varied in a series of consecutive beats by means of a volume-loading technique, and both regional and global relationships at 20-msec intervals throughout systole were found to be nonlinear and to exhibit hysteresis. In eight animals, regional hysteresis was present after vagotomy, propranolol (1.0 mg/kg), and atropine (0.1 mg/kg), and was present no matter whether hearts were loaded by volume (45-60 ml/sec) or by pressure (partial aortic occlusion) over a similar range of left ventricular systolic pressures. Elastance was linearly approximated by the slope of the major axis of the hysteresis loops. In each instance, elastance increased to a maximum and then decreased, thus defining end-systol...
Body surface mapping during percutaneous transluminal coronary angioplasty. QRS changes indicating regional myocardial conduction delay.
Authors: HSpekhorst, ASippensGroenewegen, G KDavid, M JJanse, A JDunning
Journal: Circulation (1990)

Using a radiotransparent electrode array, body surface maps (BSMs) were constructed based on simultaneous recordings from 62 leads on the entire thorax before, during, and after balloon inflation during percutaneous transluminal coronary angioplasty (PTCA). Twenty-five patients were studied, and 30 angioplasties were performed; 20 patients had one-vessel disease, and five patients had two-vessel disease. In total, 15 dilations in the left anterior descending artery (LAD), seven in the right coronary artery (RCA), and eight in the left circumflex artery (LCx) were studied. For each patient, the BSM and the QRS integral map before, during, and after the inflation was compared by subtraction of recordings during-minus-before inflation and before-minus-after inflation. The subtraction was performed on the results of the QRS integral maps. The conclusions derived from the inspection of the BSMs and the difference maps show specific changes in the QRS complex during ischemia related to the corresponding isc...
Molecular pathways behind acquired obesity: Adipose tissue and skeletal muscle multiomics in monozygotic twin pairs discordant for BMI
Authors: Birgitta W. van der Kolk, Sina Saari, Alen Lovric, Muhammad Arif, Marcus Alvarez, Arthur Ko, Zong Miao, Navid Sahebekhtiari, Maheswary Muniandy, Sini Heinonen, Ali Oghabian, Riikka Jokinen, Sakari Jukarainen, Antti Hakkarainen, Jesper Lundbom, Juho Kuula, Per-Henrik Groop, Taru Tukiainen, Nina Lundbom, Aila Rissanen, Jaakko Kaprio, Evan G. Williams, Nicola Zamboni, Adil Mardinoglu, Päivi Pajukanta, Kirsi H. Pietiläinen
Journal: Cell Reports Medicine (2021)

Tissue-specific mechanisms prompting obesity-related development complications in humans remain unclear. We apply multiomics analyses of subcutaneous adipose tissue and skeletal muscle to examine the effects of acquired obesity among 49 BMI-discordant monozygotic twin pairs. Overall, adipose tissue appears to be more affected by excess body weight than skeletal muscle. In heavier co-twins, we observe a transcriptional pattern of downregulated mitochondrial pathways in both tissues and upregulated inflammatory pathways in adipose tissue. In adipose tissue, heavier co-twins exhibit lower creatine levels; in skeletal muscle, glycolysis- and redox stress-related protein and metabolite levels remain higher. Furthermore, metabolomics analyses in both tissues reveal that several proinflammatory lipids are higher and six of the same lipid derivatives are lower in acquired obesity. Finally, in adipose tissue, but not in skeletal muscle, mitochondrial downregulation and upregulated inflammation are associated with a fatty liver, insulin resistance, and dyslipidemia, suggesting that adipose tissue dominates in acquired obesity.
Effects of captopril on ischemia and dysfunction of the left ventricle after myocardial infarction.
Authors: PSøgaard, C OGøtzsche, JRavkilde, KThygesen
Journal: Circulation (1993)

BACKGROUNDTreatment with angiotensin converting enzyme inhibitors has been shown to be beneficial in patients with heart failure and myocardial infarction. Experimental studies have shown beneficial effects on the ischemic myocardium.METHODS AND RESULTSThe effects of captopril were evaluated in 64 patients with left ventricular dysfunction after myocardial infarction. The patients were randomized at day 7 to either placebo or captopril (50 mg daily) in a double-blind parallel study over a period of 6 months. The patients were followed up by means of ambulatory ECG monitoring, bicycle ergometer testing, and echocardiographic examination. The duration of ST segment depression detected during ambulatory ECG monitoring was lower in the captopril group (87 minutes) than in the placebo group (638 minutes) (p < 0.001), and the number of patients in the captopril group with exercise-induced ST segment depression (p < 0.01) was lower at the completion of the study. The working capacity increased during the study p...
Characterization of regional diastolic pressure gradients in the right ventricle.
Authors: MCourtois, BBarzilai, FGutierrez, P ALudbrook
Journal: Circulation (1990)

Regional intraventricular pressure gradients exist in the left ventricle (LV) during both the early and late filling phases of diastole. These regional pressure gradients comprise a fundamental component of the mechanism of normal LV filling. To determine whether similar diastolic pressure gradients also occur in the right ventricle (RV), we measured right atrial (RA) and RV regional pressures with use of micromanometers in six anesthetized, closed-chest dogs. Tricuspid flow velocity was recorded with use of transesophageal Doppler echocardiography, and right ventriculograms were obtained with contrast angiography. As in the LV, the maximum RA-RV pressure gradient during early diastole was consistently greater if RV pressure was measured near the apex than in the inflow tract (1.6 +/- 0.5 versus 0.8 +/- 0.4 mm Hg). The area of reversed pressure was also found to be significantly greater in the apex than in the inflow tract (72 +/- 43 versus 8 +/- 6 mm Hg.msec). However, unlike the LV, the lowest minimum p...
Mithramycin inhibits myointimal proliferation after balloon injury of the rat carotid artery in vivo.
Authors: S JChen, Y FChen, D MMiller, HLi, SOparil
Journal: Circulation (1994)

BACKGROUNDSmooth muscle proliferation and extracellular matrix formation in the subintimal region of blood vessels that have been subjected to intimal injury are responsible for restenosis following balloon angioplasty of the coronary arteries and for accelerated atherosclerosis in a variety of other pathophysiological states. The immediate early-response gene c-myc is overexpressed in proliferating vascular smooth muscle cells in vitro, and c-myc antisense oligomers have been shown to reduce c-myc expression and to inhibit proliferation of vascular smooth muscle cells in culture. Mithramycin is a commercially available G-C-specific DNA binding drug that selectively inhibits transcription of genes, such as c-myc, that have G-C-rich promoter sequences. This study tested the hypothesis that mithramycin inhibits transcription of the c-myc proto-oncogene and prevents myointimal proliferation after balloon injury of the rat carotid artery in vivo.METHODS AND RESULTSTen-week-old male Sprague-Dawley rats receive...
PROCEDURAL AND 1 YEAR OUTCOMES FOLLOWING LARGE VESSEL CORONARY ARTERY PERFORATION TREATED BY COVERED STENTS IMPLANTATION - MULTICENTRE CRACK REGISTRY
Authors: Wojciech Wanha, Rafał Januszek, Michalina Kołodziejczak, Łukasz Kuźma, Mateusz Tajstra, Tomasz Figatowski, Brunon Tomasiewicz, Malwina Smolarek-Nicpoń, Monika Gruz-Kwapisz, Jerzy Bartuś, Tomasz Roleder, Adrian Wlodarczak, Jan Kulczycki, Mariusz Kowalewski, Damian Hudziak, Paweł Stachowiak, Katarzyna Sierakowska, Krzysztof Reczuch, Miłosz Jaguszewski, Sławomir Dobrzycki, Grzegorz Smolka, Stanisław Bartuś, Andrzej Ochała, Mariusz Gąsior, Wojciech Wojakowski
Journal: Journal of the American College of Cardiology (2021)
TCTAP A-025 Assessment of Coronary Collaterals and Its Clinical Determinants in Patients with Total/Subtotal Coronary Artery Occlusion – An Observational Study Conducted at a Tertiary Care Center in India
Authors: Asees Paul Singh, Hiteshi K.C. Chauhan, Arun Kochar, Pankaj Garg
Journal: Journal of the American College of Cardiology (2021)
Mechanism of calcium channel block by D600 in single smooth muscle cells from rabbit ear artery.
Authors: SHering, T BBolton, D JBeech, S PLim
Journal: Circulation Research (1989)

This study investigated the action of the calcium antagonist D600 on calcium channel currents recorded in high barium solution from single, enzymatically isolated smooth muscle cells from the rabbit ear artery using the whole cell configuration of the patch-clamp technique. D600 (1-100 microM) was applied by path perfusion or by a new technique that allowed a concentration jump during the current. Application of D600 at rest (holding potential, -60 mV) did not alter the peak inward current elicited on depolarization, but the activation of the channels led to a marked block and an acceleration of the current decay. The mechanism of block of calcium channels by D600 was studied by using pulse protocols with different pulse length and different interpulse intervals. The results were consistent with the hypothesis that D600 has a low affinity for the calcium channels in the resting state and that they have to pass to the open state before the drug affects the calcium channel current. A fast onset of the calci...
Diagnosis of coronary artery disease by controlled coronary vasodilation with adenosine and thallium-201 scintigraphy in patients unable to exercise.
Authors: M SVerani, J JMahmarian, J BHixson, T MBoyce, R AStaudacher
Journal: Circulation (1990)

Pharmacological coronary vasodilation induced by dipyridamole is often used in association with thallium-201 myocardial scintigraphy to evaluate the presence and prognostic significance of coronary artery disease. Because dipyridamole acts by blocking the cellular uptake of adenosine, we investigated the usefulness of direct intravenous administration of adenosine, a physiological substance with an exceedingly short (less than 2 seconds) plasma half-life, to induce maximal controlled coronary vasodilation in conjunction with 201Tl scintigraphy. We studied 89 patients (44 men and 45 women; mean age, 64 +/- 10 years [SD]) who were unable to perform an exercise test and were referred for evaluation of suspected coronary artery disease. The intravenous infusion of adenosine began at an initial rate of 50 micrograms/kg/min and was increased by stepwise increments every minute to a maximal rate of 140 micrograms/kg/min. 201Tl was injected intravenously after 1 minute at the highest infusion rate, followed by im...
Coronary vasomotor response to acetylcholine relates to risk factors for coronary artery disease.
Authors: J AVita, C BTreasure, E GNabel, J MMcLenachan, R DFish, A CYeung, V IVekshtein, A PSelwyn, PGanz
Journal: Circulation (1990)

In animals, acetylcholine dilates normal arteries and produces vasoconstriction in the presence of hypercholesterolemia, hypertension, or atherosclerosis, reflecting endothelial cell dysfunction. In patients with angiographically smooth coronary arteries, acetylcholine has been reported to produce both vasodilation and constriction. To test the hypothesis that the acetylcholine response relates to risk factors for coronary artery disease, acetylcholine 10(-8) to 10(-6) M was infused into the left anterior descending or circumflex coronary artery, and diameter changes were assessed with quantitative angiography in 34 patients with angiographically smooth coronary arteries. The acetylcholine response ranged from +37% (dilation) to -53% (constriction) at the peak acetylcholine dose. All coronary arteries dilated in response to nitroglycerin (26 +/- 17%), suggesting an abnormality of endothelial function in the patients with a constrictor response to acetylcholine. By multiple stepwise regression analysis, se...