tbuckley/cabot-search huggingface dataset:
Effect of changes in circulating blood volume on cardiac output and arterial and ventricular blood pressure in the stage 18, 24, and 29 chick embryo.
Authors: A JWagman, NHu, E BClark
Journal: Circulation Research (1990)

We studied the hemodynamic effects of changing volume loading in the chick embryo, before autonomic innervation, to test the hypothesis that the Frank-Starling mechanism functions in the embryonic myocardium. Dorsal aortic blood velocity was measured by pulsed Doppler. Heart rate and aortic diameter were also measured to calculate cardiac output and stroke volume index. Vitelline arterial and ventricular pressures were measured with a servo-null micropressure system in stage 24 embryos. Infusing isotonic solution intravenously resulted in linear increases in stroke volume index for stages 18 (y = 388x + 6.89), 24 (y = 466x + 7.86), and 29 (y = 549x + 4.96). The slopes and intercepts were statistically the same for all three stages. Similar volume loading in stage 24 embryos initially increased mean arterial pressure linearly, but at higher loading conditions, the rate of rise lessens. Thus, volume loading resulted in a decrease in vascular resistance. Withdrawing blood from stage 24 embryos resulted in a ...
Effects of exercise on aortic input impedance and pressure wave forms in normal humans.
Authors: J PMurgo, NWesterhof, J PGiolma, S AAltobelli
Journal: Circulation Research (1981)

The effects of supine bicycle exercise on the input impedance of the ascending aorta were studied in thirteen male subjects undergoing cardiac catheterization, but in whom no cardiovascular disease was found. Ascending aortic flow velocity and pressure were recorded simultaneously from a multisensor catheter with an electromagnetic flow velocity probe and a pressure sensor mounted at the same location. A second pressure sensor at the catheter tip provided left ventricular pressure. Fick cardiac outputs were used to scale the velocity signal to instantaneous volumetric flow. Input impedance was calculated from 10 harmonics of aortic pressure and flow. For each subject, impedance moduli and phases from a minimum of 15 beats during rest and exercise were averaged. Peripheral resistance decreased from a resting value of 1142 +/- 51 (+/- SE) dynes sec/cm5 to 712 +/- 39 dynes sec/cm5 during exercise. Characteristic impedance remained unchanged with a resting value of 47 +/- 4 dynes sec/cm5 and an exercise value...
Abstract 131: Retrospective Study of The Timing Of Additional Therapy For Severe Kawasaki Disease Before And After The Induction Of Raise Study Protocol
Authors: Hiroshi Katayama, Kanta Kishi, Ozaki Noriyasu, Yutaka Odanaka, Hiroshi Tamai
Journal: Circulation (2015)

Background: The RAISE study showed that combination therapy with intravenous immunoglobulin (IVIg) and prednisolone (PSL) improved coronary artery outcomes in patients with severe Kawasaki disease (KD). We encountered KD cases in which fever and findings such as WBC were masked by the steroid administration in combination therapy. We hypothesized that combination therapy might delay second- and third-line therapy for severe KD. Purpose: The goal of the study was to investigate whether combination therapy with IVIg and PSL might delay second- and third-line therapy for severe KD patients. Methods: We retrospectively investigated clinical data from acute KD patients admitted to our hospital from January 2011 to September 2014. We examined the following: 1) prediction score for refractory KD 2) first-line therapy for KD (IVIg group, n=10; IVIg/PSL group, n=11); 3) additional rescue therapy such as additional IVIg, steroid pulse therapy, plasma exchange, and so on 4) period from KD onset to end of main therapy for KD; 5) day of increased albumin from previous examination; and 6) day of CRP reaching &lt;1.0 mg/l. Results: Seventy-four acute KD patients were admitted to our hospital during the study period. Only 1 KD patient had coronary artery lesions (CAL) at 1 month after onset. Detailed data were as follows: 1) Twenty-one patients were at high risk for refractory KD. 2) number of patients with additional IVIg (IVIg, 6/10; IVIg/PSL, 6/11); 3) number of patients with steroid pulse therapy (IVIg, 4/10; IVIg/PSL, 4/11); 4) period from KD onset to end of main therapy (IVIg, 8.3 days; IVIg/PSL, 8.7 days); 5) day of increased albumin (IVIg, 12.0 days; IVIg/PSL, 11.8 days); 6) day of CRP reaching &lt;1.0 mg/l (IVIg, 13.7 days; IVIg/PSL, 11.4 days). No differences between IVIg and IVIg/PSL groups were seen for any factor. Discussion and conclusion: In this study, overall frequency of CAL was 1.3%, lower than that reported from nationwide surveillance in Japan. This study found no differences between groups in regard to frequency or timing of additional therapy and response. We concluded that combination therapy with IVIg and PSL did not delay the timing of additional therapy for acute KD. The cohort for this retrospective study was small, and further investigation is thus needed.
Effect of serial brief ischemic episodes on extracellular K+, pH, and activation in the pig.
Authors: W FFleet, T AJohnson, C AGraebner, L SGettes
Journal: Circulation (1985)

This study was performed to determine the reproducibility of the ionic and electrical changes associated with serial ischemic episodes. We used ion-selective and bipolar plunge electrodes to determine the changes in left ventricular extracellular potassium ([K+]e), extracellular pH (pHe), and local activation during sequential 10 min occlusions of the left anterior descending coronary artery separated by 50 min of reperfusion in open-chest anesthetized pigs. We found that uniformly during the initial occlusion, and in approximately 50% of animals during the second occlusion, [K+]e rose more rapidly but to a lower level than in subsequent occlusions. By the third occlusion the changes in [K+]e were reproducible. Extracellular acidosis was greatest in the first occlusion and decreased progressively with each subsequent occlusion. Local activation was characterized by a decrease in spontaneous improvement and increase in block with each successive occlusion. The occurrence of ventricular fibrillation could n...
Aortic impedance and hydraulic power in the chick embryo from stages 18 to 29.
Authors: K GZahka, NHu, K PBrin, F CYin, E BClark
Journal: Circulation Research (1989)

Little is known about the hemodynamic properties of the rapidly expanding arterial bed during embryonic development. Using a servo-null pressure system and 20-MHz pulsed Doppler velocity meter, we recorded simultaneous dorsal aortic pressure and velocity waveforms. The waveforms were digitized at 3-msec intervals and subjected to Fourier analysis. We calculated hydraulic energy and the impedance spectrum to 10 Hz. From stages 18 to 29, heart rate (148 +/- 3 to 193 +/- 9 beats/min), systolic pressure (1.14 +/- 0.12 to 3.04 +/- 0.10 mm Hg), and mean dorsal aortic blood flow (21 +/- 2 to 214 +/- 19 mm3/min) increased. Peripheral vascular resistance (Z0: 30.4 +/- 4.8 to 6.4 +/- 0.7 dyne x sec/mm5), and the impedance moduli (Z1: 6.5 +/- 1.0 to 1.7 +/- 0.2 dyne x sec/mm5; Z2: 6.1 +/- 1.2 to 1.7 +/- 0.1 dyne x sec/mm5; Z3: 7.3 +/- 1.1 to 1.7 +/- 0.2 dyne x sec/mm5) decreased. Total hydraulic power increased from 48 +/- 7 to 2,606 +/- 96 nW, while the proportion of oscillatory energy increased from 29 +/- 2% to 6...
Relationship of contractile state to ejection performance in patients with chronic aortic valve disease.
Authors: TWisenbaugh, DBooth, ADeMaria, SNissen, JWaters
Journal: Circulation (1986)

To assess the relative contributions of afterload mismatch and impaired contractility to pump dysfunction in patients with chronic aortic valve disease, simultaneous left ventricular cineangiography and micromanometry were performed in 56 patients: 21 with severe aortic stenosis, 16 with severe aortic regurgitation, and 19 normal control subjects. Left ventricular mass was increased in patients with aortic stenosis and aortic regurgitation (172 +/- 52 and 224 +/- 63 g/m2, respectively, vs 89 +/- 16 for control subjects; p less than .05) as were end-diastolic volume (101 +/- 39 and 167 +/- 44 vs 77 +/- 16 ml/m2; p less than .05) and end-systolic volume (50 +/- 40 and 84 +/- 43 vs 24 +/- 7 ml/m2; p less than .05). Although ejection fraction was depressed in both abnormal groups (0.56 +/- 0.18 for patients with aortic stenosis and 0.53 +/- 0.13 for those with aortic regurgitation vs 0.69 +/- 0.05 for control subjects; p less than .05), the decrease in ejection fraction was disproportionate to the mild degree...
Effect of tissue anisotropy on extracellular potential fields in canine myocardium in situ.
Authors: D ERoberts, A MScher
Journal: Circulation Research (1982)

The extracellular epicardial potential fields produced by simple depolarization waves in the in situ canine left ventricular myocardium were analyzed. A mathematical model that included tissue anisotrophy was developed to explain the observed fields. Values of intracellular (i), extracellular (o), longitudinal (l), and transverse (t) resistivity which gave the best fit between the model and experimental data were (in ohm-cm, mean +/- SD): rol = 852 +/- 232, rot = 1247 +/- 210, ril = 291 +/- 38, rit = 1677 +/- 331. The potential fields around simple stimulated waves on the epicardium can best be explained if the extracellular wavefront voltage is (mean +/- SD) 74 +/- 7 mV for a wave propagating parallel to the local muscle fibers, and 43 +/- 6 mV for a wave propagating perpendicular to these fibers. We conclude that the anisotrophy of the electrical conductivity of cardiac muscle has important effects on he propagation of waves of depolarization and on the potential fields produced by depolarization in the...
Autonomic dysfunction in women with mitral valve prolapse syndrome.
Authors: F AGaffney, E SKarlsson, WCampbell, J ESchutte, J VNixon, J TWillerson, C GBlomqvist
Journal: Circulation (1979)

Autonomic cardiovascular regulation was evaluated in 35 women, 19 with mitral valve prolapse and 16 healthy controls. Heart rate responses to the diving reflex and to phenylephrine infusion were diminished in patients. Noninvasive measures of cardiac output, heart rate, blood pressure, forearm flow and leg volume during lower body negative pressure (LBNP) showed that patients had less lower extremity pooling of blood and had lower forearm conductance. Blood pressures during LBNP rose or remained unchanged despite decreases in cardiac output of 20--25%. These data indicate that mitral valve prolapse patients have an increased venous and arterial vasoconstrictor activity. Cardiac output at rest and echocardiographic indices of contractility were normal. Patients with a history of significant ventricular arrhythmias had higher heart rates and lower forward stroke volumes than the other patients or controls. The combined data demonstrate autonomic dysfunction in women with the mitral valve prolapse syndrome a...
Blood pressure response to central and/or peripheral inhibition of phenylethanolamine N-methyltransferase in normotensive and hypertensive rats.
Authors: JBlack, BWaeber, M RBresnahan, IGavras, HGavras
Journal: Circulation Research (1981)

We studied the effects on blood pressure and heart rate of two different phenylethanolamine N-methyltransferase (PNMT) inhibitors in normotensive, in two-kidney renal hypertensive, and in deoxycorticosterone-salt (DOC-salt) hypertensive rats. One compound (SK&F 64139) blocks the conversion of norepinephrine to epinephrine in both the central and the peripheral nervous system, whereas the other (SK&F 29661) does not cross the blood-brain barrier and therefore is active mostly in the adrenal glands. In the rats given SK&F 29661, practically no acute blood pressure changes were in the adrenal glands. In the rats given SK&F 64139 induced only a minor blood pressure and heart rate response in normotensive and two-kidney renal hypertensive rats. However, in DOC-salt hypertensive rats, it reduced arterial pressure to approximately normal levels and concomitantly slowed pulse rate. There was a close correlation between the magnitude of the blood pressure response observed in all SK&F 64139-treated animals and the...
Combined fludarabine and rituximab for low grade lymphoproliferative disorders
Authors: David G. Savage, Gwen Nichols, Neil S. Cohen, Charles S. Hesdorffer, Robert March, Mathew Lonberg, Thomas J. Garrett, Javier Ruiz, Michael Flamm, J. G. Mears, Andrea Troxel, Anna Parke, Michael Rock
Journal: Blood (2000)
What's hot that the other lot got
Authors: Victoria Connor
Journal: Thorax (2019)

What's hot that the other lot got Victoria connorPseudomonas aeruginosaacquired pneumonia: international prevalence and risk factorsCommunity acquired pneumonia (CAP) is a major cause of morbidity and mortality worldwide.The contribution of Pseudomonas aeruginosa to both disease burden and antibiotic resistance is unclear; Restrepo et al (European Respiratory Journal 2018;52: 1701190) present a point-prevalence study to address this gap in the data.This multinational study of hospitalised patients investigated the prevalence, risk factors and antibiotic resistance profiles of P. aeruginosa-CAP in 54 countries.A total of 3193 patients were included, all had microbiological testing on admission and had a confirmed diagnosis of CAP.Prevalence of P. aeruginosa-CAP was 4.2 % (133/3193) which represented 11.3 % (133/1173) of all patients with a positive bacterial culture result.Almost half of these patients had an antibiotic-resistant strain (64/133, 48 %; 2.0 % of total cohort) and a quarter had a multi-drug resistant strain of P. aeruginosa (33/133, 25 %; 1.0 % of total cohort).Prior Pseudomonas infection/colonisation (OR 16.10, 95% CI 9.48 to 27.35), prior tracheostomy (OR 6.50, 95% CI 2.61 to 16.19), bronchiectasis (OR 2.88, 95% CI 1.65 to 5.05), patients requiring invasive respiratory and/or vasopressor support (OR 2.33, 95% CI 1.44 to 3.78) and very severe chronic obstructive pulmonary disease (COPD) (OR 2.67, 95% CI 1.25 to 6.06) were all independent risk factors associated with the development of P. aeruginosa-CAP.The study suggests that the risk of P. aeruginosa-CAP is low in hospitalised patients with a diagnosis of CAP but identifiable risk factors may be used to help direct anti-pseudomonal antibiotic therapy.
Developmental changes in the expression of rabbit left ventricular troponin T.
Authors: P AAnderson, G EMoore, R NNassar
Journal: Circulation Research (1988)

We examined cardiac troponin T (TnT) isoform expression in rabbit left ventricular myocardium at three different stages of postnatal development. Using sodium dodecyl sulfate gel electrophoresis (PAGE), we resolved five isoforms: TnT1, TnT2, TnT3, TnT4, and TnT5. TnT1 had the slowest electrophoretic mobility and TnT5 the fastest. The predominant isoforms were TnT2, TnT3, and TnT4. The relative amounts of TnT2, TnT3, TnT4, and TnT5 were examined in myocardium from three age-groups: 3 days (Group 1), 21-22 days (Group 2), and 99-109 days (Group 3). The amount of TnT2 relative to the total amount of TnT (determined by the ratio of the areas under the densitometric curves) decreased significantly (p less than 0.01) with age from 42 +/- 4% in Group 1 to 25 +/- 3% in Group 3. In contrast, the relative amount of TnT4 increased with age from 23 +/- 2% in Group 1 to 33 +/- 4% in Group 3 (p less than 0.01). The relative amounts of the other two isoforms change biphasically with development: TnT3 decreased from Grou...
The effects of lidocaine and quinidine on impulse propagation across the canine Purkinje-muscle junction during combined hyperkalemia, hypoxia, and acidosis.
Authors: J JEvans, R FGilmour, D PZipes
Journal: Circulation Research (1984)

During ischemia, lidocaine or quinidine may prevent arrhythmias by blocking conduction without suppressing abnormal automaticity. The purpose of this study was to determine whether lidocaine or quinidine (5 micrograms/ml) produced Purkinje fiber-papillary muscle block during superfusion in vitro with an altered Tyrode's solution containing some components of ischemia: 6 mM potassium, PO2 less than 40, pH = 6.8. Unbranched canine Purkinje fibers connected to papillary muscle at one end were threaded through a three-chamber bath with Purkinje fiber-papillary muscle in the left chamber and Purkinje fiber alone in the middle and right chambers. Action potentials were recorded using microelectrodes from Purkinje fiber, papillary muscle, and cells at the Purkinje fiber-papillary muscle junction. Purkinje fiber or papillary muscle was stimulated at 1.5-4 Hz. Perfusion of the left chamber with altered Tyrode's solution decreased resting membrane potential, action potential amplitude, and the maximum rate of rise ...
Primary pulmonary hypertension. Vascular structure, morphometry, and responsiveness to vasodilator agents.
Authors: H IPalevsky, B LSchloo, G GPietra, K TWeber, J SJanicki, ERubin, A PFishman
Journal: Circulation (1989)

The use of pharmacologic agents in the treatment of pulmonary hypertension has not proved to be uniformly successful or predictable. One possible reason for the vagaries in response is that the pulmonary vascular lesions are not consistent. We examined the relation between the structure of the pulmonary resistance vessels in unexplained (primary) pulmonary hypertension and the response to pulmonary vasodilators. Our study involved 19 patients with clinically unexplained pulmonary hypertension (mean pressure, 59 +/- 14 mm Hg). After characterizing them clinically and performing control hemodynamic measurements, we determined the acute effects of a series of vasodilator agents that have different mechanisms of action. In 16 patients, lung biopsy material was related to the hemodynamic studies; in nine patients, including six who had undergone open lung biopsy, the hemodynamic studies were related to the pathologic changes found at autopsy. Histologic specimens from all 19 patients were evaluated qualitative...
High-current stimuli to the spared epicardium of a large infarct induce ventricular tachycardia.
Authors: K MKavanagh, J SKabas, D LRollins, S BMelnick, W MSmith, R EIdeker
Journal: Circulation (1992)

BACKGROUNDPrevious studies have demonstrated that both ventricular tachycardia (VT) and ventricular fibrillation (VF) may begin as figure-eight reentry: VT with a longer cycle length from spared tissue adjacent to an infarct by programmed stimulation and VF with a shorter cycle length from noninfarcted tissue by a large premature S2 stimulus. These results suggest that the type of tissue or cycle length of the arrhythmia rather than the mode of induction determines whether the figure eight becomes sustained VT or degenerates into VF. Thus, a protocol similar to that by which a VF threshold is determined may induce VT rather than VF when performed in the spared tissue over an infarct.METHODS AND RESULTSIn 10 dogs, 4 days after occlusion-reperfusion of the left anterior descending coronary artery, 10 S1 stimuli were delivered from a total of 34 right and left ventricular sites outside the infarct. An epicardial S2 stimulus over the infarct was increased in 10-mA steps and introduced in diastole at decreasin...
Sodium channel block produces opposite electrophysiological effects in canine ventricular epicardium and endocardium.
Authors: S CKrishnan, CAntzelevitch
Journal: Circulation Research (1991)

Using microelectrode techniques we compared the effects of tetrodotoxin (TTX, 2-3 microM), DL-propranolol (1-3 micrograms/ml), and flecainide acetate (10-15 microM) on isolated canine ventricular epicardial (epicardium) and endocardial (endocardium) tissues. Propranolol, TTX, and flecainide decreased Vmax and phase 0 amplitude in a use-dependent manner in both tissues. The effects of propranolol were slow to develop and wash out. TTX and propranolol always abbreviated action potential duration in endocardium. Action potential duration was abbreviated by 23.8 +/- 5.6 msec after propranolol (1 microgram/ml, basic cycle length [BCL] = 1,000 msec) and 10.8 +/- 12.9 msec after TTX (2 microM, BCL = 1,000 msec). In epicardium, the reduction of phase 0 and 1 amplitudes led to a slowing of the second action potential upstroke and an increase in the amplitude of phase 2. This accentuation of the notch resulted in a paradoxical prolongation of the epicardial action potential. Action potential duration was prolonged ...
Rapidly progressive obstructive cardiomyopathy in infants with Noonan's syndrome. Report of two cases.
Authors: H DHirsch, HGelband, OGarcia, SGottlieb, D MTamer
Journal: Circulation (1975)

Two patients with hypertrophic obstructive cardiomyopathy and Noonan's syndrome are presented. Both patients were found at postmortem examination to have gross malformation of the mitral valve and obliteration of the left ventricle due to muscle hypertrophy. Each case demonstrated similar clinical, echocardiographic, and angiographic findings. The poor response to medical and surgical therapy are noted.
Studies of amiodarone during experimental myocardial infarction: beneficial effects on hemodynamics and infarct size.
Authors: L WDeBoer, J JNosta, R AKloner, EBraunwald
Journal: Circulation (1982)

The effect of amiodarone was investigated in a canine model of myocardial infarction. The left anterior descending coronary artery was occluded in 24 anesthetized dogs. After 15 minutes of coronary artery occlusion, the ischemic myocardium at risk of necrosis was determined by labeling the heart with technetium-99m-labeled human albumin microspheres injected into the systemic circulation through the left atrium, and the dogs were than randomized to either a saline-treated control group (n = 13) or an amiodarone-treated group (n = 11) that received i.v. amiodarone, 10 mg/kg, administered in a single bolus 30 minutes after coronary artery occlusion. Myocardial infarct size was determined directly after 6 hours of coronary occlusion by incubation of sections of myocardium in triphenyltetrazolium chloride, a dehydrogenase stain, and expressed as a percentage of left ventricle below occlusion. Autoradiography of the stained myocardial sections was performed to determine the ischemic myocardium at risk of necro...
The effect of exchanger inhibitory peptide (XIP) on sodium-calcium exchange current in guinea pig ventricular cells.
Authors: T KChin, K WSpitzer, K DPhilipson, J HBridge
Journal: Circulation Research (1993)

We investigated the effect of exchanger inhibitory peptide (XIP) on Na-Ca exchange current (INa-Ca) in guinea pig ventricular cells. Cells were voltage-clamped with microelectrodes containing 20 mM Na+ and 14.0 mM EGTA ([Ca]i = 100 nM). An outward putative exchange current was stimulated when extracellular Na+ was reduced from 144 mM to zero (Li+ replaced Na+). This outward current showed a significant dependence on extracellular Ca2+. When Na+ removal was delayed for up to 40 minutes (in the absence of extracellular K+ or the presence of 3.0 mM ouabain to block the Na+ pump), outward INa-Ca increased presumably because [Na]i increased. Time-dependent increases of outward current in the absence of K+ could be abolished by reapplication of K+, which presumably reactivates the Na+ pump and reduces intracellular Na+. This effect is blocked in the presence of 3.0 mM ouabain. The dependence of this current on extracellular Ca2+, its dependence on intracellular Na+, and activation by extracellular Na+ reduction...