tbuckley/cabot-search huggingface dataset:
The feedback regulation of angiotensinogen production by components of the renin-angiotensin system.
Authors: H CHerrmann, V JDzau
Journal: Circulation Research (1983)

The in vivo generation of angiotensin appears to be dependent on both plasma renin and angiotensinogen concentrations. Much less is known about the control of hepatic angiotensinogen synthesis and release, as compared to that of renin. In this study, we examined the feedback regulation of angiotensinogen synthesis and release by various components of the renin-angiotensin system, using an in vitro rat liver slice system. Livers were removed for study from rats which were subjected to various systemic infusions or physiological perturbations. Infusion of angiotensin II has been reported to increase angiotensinogen release rate. However, infusion of angiotensin I (with simultaneous suppression of plasma renin by antirenin antibody infusion and angiotensin II production by captopril administration) had no effect on the angiotensinogen release rate. Direct infusion of renin in rats treated with captopril resulted in further suppression of the angiotensinogen release rate, compared with those given captopril a...
Two-dimensional echocardiographic detection of pulmonary venous channel stenosis after Senning's operation.
Authors: GSatomi, KNakamura, ATakao, YImai
Journal: Circulation (1983)

Stenosis of the common pulmonary venous (PV) channel after Senning's operation for complete transposition of the great arteries is a serious problem, and a method for noninvasive diagnosis is highly desirable. Therefore, our purpose was to devise a method to diagnose PV channel stenosis noninvasively. The newly created common PV channels were measured and the short-axis views of the left ventricle were observed by means of two-dimensional echocardiography in 16 patients who had undergone Senning's procedure. In seven patients we used the original procedure and in nine patients we used a modified procedure with a pedicled pericardial patch. The shape of the left ventricle became round abruptly when the width of the PV channel decreased below a critical value (a range of 6 to 9 mm). Three patients with a relatively round-shaped left ventricle and a narrow PV channel (below 9 mm) were all confirmed to have PV channel stenosis at reoperation. All of the patients with a wide PV channel (above 10 mm) and a flat...
Respiratory Syncytial Virus
Journal: BMJ (1961)

Respiratory syncytial virus (RSV) is ubiquitous, causing epidemics annually worldwide [1]. Community attack rates are usually high (3050%), and almost all children have an RSV infection by 3 years of age [2]. The majority of these infections are subclinical or mild. However, if virus descends to the lower respiratory tract, serious manifestations and even death can occur.
Three-dimensional potential gradient fields generated by intracardiac catheter and cutaneous patch electrodes.
Authors: A STang, P DWolf, YAfework, W MSmith, R EIdeker
Journal: Circulation (1992)

BACKGROUNDDefibrillation may be improved if electrode configurations can be found that create a larger and more even voltage gradient field across the heart. This study determined the magnitude of the shock gradient fields generated by four nonthoracotomy electrode configurations for defibrillation.METHODS AND RESULTSIn six dogs, a catheter was inserted containing a right ventricular apical electrode (V) and a right atrial electrode (A). A cutaneous patch electrode (P) was placed on the left lateral thorax. Shock potentials were recorded simultaneously from 128 electrodes in the left ventricular and right ventricular subepicardium and subendocardium, ventricular septum, and atria. With the chest closed, 50-mA shocks were given during diastole via the following lead configurations: V----A (V, cathode; A, anode); V----P; V----A+P; and V+A----P. Potential gradients were calculated at the subepicardium and subendocardium in millivolts per centimeter per volt of shock. In most dogs, the V----A+P configuration ...
Generalized pustular psoriasis complicated by acute respiratory distress syndrome
Authors: T. Abou-Samra, J-M. Constantin, S. Amarger, S. Mansard, P. Souteyrand, J-E. Bazin, M. D'Incan
Journal: British Journal of Dermatology (2004)

Psoriasis has a chronic and relatively benign course. However, severe complications are possible. One rare complication is acute interstitial pneumonitis. This entity should be suspected when a patient presents with dyspnoea and high fever. Knowledge of this pathology is crucial, for although it is essential to rule out aetiologies requiring specific management such as microbial infection or drug-related syndromes, diagnosis should not be delayed as its severe clinical course is improved by corticosteroids. We report two patients with an acute respiratory distress syndrome arising during the course of pustular psoriasis. Repeated bacteriological testing in lungs and blood remained negative. In both cases lung involvement was severe, requiring artificial ventilation. Dramatic clinical resolution was obtained by using corticosteroids. Besides infectious causes and drug hypersensitivity to methotrexate or acitretin, acute respiratory distress syndrome, sometimes due to a pulmonary capillary leak syndrome, is a rare cause of pneumonitis in the course of psoriasis, and may be fatal. Its pathogenesis is unknown. However, animal models suggest a role for T-helper (Th) 1 lymphocytes, known to be activated in psoriasis, and a role for tumour necrosis factor-alpha, a major Th1 cytokine, in alveolar damage.
Letter by Erdoes et al Regarding Article, “Cerebral Embolization During Transcatheter Aortic Valve Implantation: A Transcranial Doppler Study”
Authors: Gabor Erdoes, Stephan Windecker, Balthasar Eberle
Journal: Circulation (2013)

We read with great interest the article by Kahlert et al 1 quantifying high-intensity transient signals by transcranial Doppler ultrasonography during transcatheter aortic valve implantation (TAVI).The results corroborate our previous findings in 67 consecutive patients undergoing transfemoral and transapical TAVI with self-expanding and balloon-expandable prostheses. 2 Both series revealed procedural high-intensity transient signals in all patients, with the highest load during deployment of transfemorally introduced self-expanding prostheses.We also concur with most of the recommendations to reduce the risk of periprocedural cerebral embolism, including reduction of mechanical trauma to aortic intimal surfaces and valvular calcifications, avoidance of long-lasting preimplantation maneuvers, etc.We respectfully disagree, however, with one of the suggested strategies to reduce cerebral embolic load, namely carotid artery compression during valve positioning and deployment.It has been shown that even surgical dissection before carotid endarterectomy, 3,4 as well as carotid angiography and stenting, 4 can disrupt carotid plaque and dislodge transcranial Doppler-detectable emboli into the cerebral circulation.In our cohort, 16% of the patients had carotid stenoses of >50% 2 ; Kahlert et al describe in 35% of their study population a prevalence of carotid artery plaques or stenosis of ≥30%. 1 Thus, in the geriatric population typically undergoing TAVI, the presence of potentially vulnerable atherosclerotic plaques in the carotid arteries is noteworthy.In addition, external compression of a carotid artery after complicated attempts to cannulate the internal jugular vein has been found to carry significant risks, including stroke. 5n our opinion, a minimal touch principle should apply to both endoluminal and external aortic arch vessel manipulation.In preparation for TAVI, we perform internal jugular venous cannulation as access for rapid ventricular pacing with ultrasound guidance to avoid trauma to the atherosclerotic carotid arteries.During TAVI procedures, we consider attempts to reduce iatrogenic cerebral embolization by means of carotid artery compression as ill-advised and possibly counterproductive.
Guidelines for long-term management of patients with Kawasaki disease. Report from the Committee on Rheumatic Fever, Endocarditis, and Kawasaki Disease, Council on Cardiovascular Disease in the Young, American Heart Association.
Authors: A SDajani, K ATaubert, MTakahashi, F ZBierman, M DFreed, PFerrieri, MGerber, S TShulman, A WKarchmer, WWilson
Journal: Circulation (1994)

Long-term management of patients with Kawasaki disease should be tailored to the degree of coronary arterial involvement. This committee has made recommendations for each risk level about antiplatelet and anticoagulant therapy, physical activity, follow-up assessment by a pediatric cardiologist or primary care physician, and the appropriate diagnostic procedures that may be performed to evaluate cardiac disease. The risk level for a given patient with coronary arterial involvement may change over time because of changes in coronary artery morphology. The recommendations for management presented here are intended as practical interim guidelines until additional prospective or retrospective data are compiled to define more clearly the natural history of Kawasaki disease.
Differential sensitivity of canine cardiac sarcolemmal and microsomal enzymes to inhibition by free radical-induced lipid peroxidation.
Authors: J HKramer, I TMak, W BWeglicki
Journal: Circulation Research (1984)

Sarcolemmal and microsomal membranes prepared from adult canine cardiac myocytes (sarcolemmal Na+, K+-ATPase = 71.8 mumol/mg per hr and microsomal rotenone-insensitive NADH cytochrome c reductase = 114 mumol/mg per hr) were each preincubated at 37 degrees C in the presence of a free radical generating system consisting of dihydroxyfumarate and Fe -ADP; loss of the Na+, K+-ATPase and reductase activities, as well as the associated increases in lipid peroxidation, measured by malondialdehyde formation, were temporally correlated in both systems. The ATPase was inhibited 70% when the malondialdehyde was 71 nmol/mg protein at 20 minutes and 90% when malondialdehyde was 138 nmol/mg protein at 90 minutes. Inhibition of reductase activity occurred more gradually, displaying a 27% loss of activity when malondialdehyde reached 34 nmol/mg protein at 20 minutes and 60% with a malondialdehyde value of 67 nmol/mg protein at 90 minutes. The greater susceptibility of the sarcolemma to free radical-induced membrane damag...
Pituitary acrogigantism and ectopic Cushing's syndrome
Authors: Hiya Boro, Sarah Alam, Alpesh Goyal, Shreya Datta Gupta, Nishikant Damle, Devasenathipathy Kandasamy, Rajesh Khadgawat, Nikhil Tandon
Journal: The Lancet Diabetes & Endocrinology (2021)
Comparative effect of verapamil and nitroglycerin on collateral blood flow.
Authors: RForman, CEng, E SKirk
Journal: Circulation (1983)

The effects of intracoronary verapamil and nitroglycerin on collateral blood flow were compared under conditions where coronary perfusion pressure was held constant with a servopump and the systemic effects of the drugs were minimal. Both drugs were infused into 12 anesthetized dogs after occlusion of the left anterior descending coronary artery (LAD) and regional myocardial blood flow (MBF) was measured using microspheres. Before the LAD occlusion, the myocardium not perfused by the LAD was labeled to permit calculation of the fraction of tissue normally perfused in the LAD samples and corrections for collateral flow. The central ischemic zone contained 2.5 +/- 0.3% normally perfused myocardium and a 4-mm border zone contained 26.8 +/- 4.3% normal myocardium. This border zone contained 10% of the total tissue supplied by the LAD. The MBF in the central ischemic zone increased from 0.101 +/- 0.019 to 0.113 +/- 0.022 ml/min/g after verapamil infusion (NS) and to 0.149 +/- 0.024 ml/min/g after nitroglycerin...
Myocardial sulfhydryl pool alterations occur during reperfusion after brief and prolonged myocardial ischemia in vivo.
Authors: E JLesnefsky, I MDauber, L DHorwitz
Journal: Circulation Research (1991)

Myocardial sulfhydryl (SH)-containing compounds, including reduced glutathione (GSH), are both defenses against and potential markers of reactive oxygen metabolite injury during ischemia and reperfusion. We examined the alterations in GSH and other myocardial SH pools during reperfusion in anesthetized dogs exposed to brief (15 minutes, n = 7) or prolonged (90 minutes, n = 6) regional ischemia caused by occlusion of the left anterior descending artery. Ninety minutes of ischemia followed by 5 hours of reperfusion, which resulted in myocardial necrosis of 43.9 +/- 4.0% of the area at risk, caused a 22% reduction in total myocardial SH groups (p less than 0.01), a 57% decrease in nonprotein myocardial SH groups (p less than 0.01), a 56% decrease in GSH (p less than 0.01), and a 62% decrease in non-GSH, nonprotein SH groups (p less than 0.02). However, protein SH groups were not significantly reduced (12% decrease, p = NS). Also, myocardial release of GSH and oxidized glutathione (GSSG) into the coronary ven...
Ultrasonic backscatter and collagen in normal ventricular myocardium.
Authors: R MHoyt, D JSkorton, S MCollins, H EMelton
Journal: Circulation (1984)

Integrated ultrasonic backscatter has been related to collagen deposition in fibrotic myocardium. The purpose of our study was to measure the integrated ultrasonic backscatter in the right and left ventricles of 10 normal freshly excised canine hearts and five normal formalin-fixed human hearts. A 2.25 MHz, 50% fractional bandwidth transducer was positioned at the transducer focal distance from the epicardium. The radio frequency backscatter signal, excluding specular reflections, was digitized, squared, and integrated to yield the integrated ultrasonic backscatter (in decibels down from a 100% reflector). The segment of myocardium corresponding to the integrated ultrasonic backscatter sample volume was excised and assayed for hydroxyproline, a marker for collagen. A second purpose of our study was to evaluate the influence of fixation with formalin on the backscatter. Regional integrated ultrasonic backscatter was therefore measured in 10 freshly excised canine left ventricles, which were fixed in 10% fo...
Length of excitation wave and susceptibility to reentrant atrial arrhythmias in normal conscious dogs.
Authors: P LRensma, M AAllessie, W JLammers, F IBonke, M JSchalij
Journal: Circulation Research (1988)

We calculated the wavelength of the atrial impulse in chronically instrumented conscious dogs by measuring both conduction velocity and refractory period: wavelength = refractory period X conduction velocity. Implantation of multiple stimulating and recording electrodes allowed wavelength determination at four different areas: the right and left parts of Bachmann's bundle and the free walls of the right and left atria. During programmed electrical stimulation, three types of arrhythmias were observed: rapid repetitive responses, atrial flutter, and atrial fibrillation. During normal rhythm, the wavelength of the atrial impulse varied between 14 and 18 cm. Premature beats had a shorter wavelength, depending on the degree of prematurity. Premature beats that evoked rapid repetitive responses showed a critical shortening of the wavelength below 12.3 cm. Episodes of atrial flutter were induced at a wavelength below 9.7 cm, while fibrillation occurred at wavelengths shorter than 7.8 cm. We correlated the induc...
Electrophysiological study of cardiovascular neurons in the rostral ventrolateral medulla in rats.
Authors: D LBrown, P GGuyenet
Journal: Circulation Research (1985)

In urethane-anesthetized rats, electrophysiological recordings of spontaneously active neurons in the vasopressor area of the rostral ventrolateral medulla were analyzed for participation in cardiovascular regulation. A total of 138 units were found which were inhibited by transient increases in mean arterial pressure elicited by intravenous injection of norepinephrine, aortic occlusion, or electrical stimulation of the hypothalamus, with 100% inhibition occurring at 148 mm Hg. Histograms of postsystolic activity showed that these units had pulse-synchronous rhythms which grew more prominent as arterial pressure increased. Furthermore, electrical stimulation of the superior laryngeal nerve, which elicited a vasodepressor response, strongly inhibited these units. Thus, these neurons were termed negatively correlated cardiovascular units. At least half of these cells project to or through the thoracic spinal cord. In addition, arterial pressure sensitivity is conveyed through carotid sinus and aortic arch a...
Effect of stimulation of carotid chemoreceptors on total and regional cerebral blood flow.
Authors: D DHeistad, M LMarcus, J CEhrhardt, F MAbboud
Journal: Circulation Research (1976)

This study was performed to determine whether stimulation of the carotid chemoreceptors increases total or regional cerebral blood flow and whether activation of arterial chemoreceptors contributes to cerebral vasodilation during systemic hypoxemia. In anesthetized and ventilated dogs, carotid chemoreceptors were stimulated with nicotine or hypoxic and hypercapnic blood. To measure total and regional cerebral blood flow, we used labeled 15-mu microspheres. Stimulation of chemoreceptors did not increase cerebral blood flow or produce significant redistribution of cerebral blood flow, even though the chemoreflex was intact in these animals (as manifested by vasoconstriction in muscle, kidney, and small bowel) and the cerebral vessels dilated in response to systemic hypercapnia. In other studies in anesthetized, ventilated dogs and rhesus monkeys, cerebral vasodilator responses to systemic hypoxemia were observed before and after denervation of carotid and aortic chemoreceptors. Systemic hypoxemia produced l...
Artificial Intelligence(AI) In Endoscopy-Deep Learning for Scoring of Ulcerative Colitis Disease Activity Under Multiple Scoring Systems
Authors: MF Byrne, JE East, M Iacucci, R Panaccione, R Kalapala, NR Duvvur, H Rughwani, AP Singh, ML Henkel, N Parsa, L Canaran, G Laage, L St-Denis, S Nikfal, J Asselin, R Monsurate, ED Cremonese, F Soudan, SP Travis
Journal: Endoscopy (2021)

Aims Computer vision & deep learning(DL)to assess & help with tissue characterization of disease activity in Ulcerative Colitis(UC) through Mayo Endoscopic Subscore(MES)show good results in central reading for clinical trials.UCEIS(UC Endoscopic Index of Severity) may be more reflective of disease activity and more primed for artificial intelligence(AI). We set out to create a UC detection&scoring support tool for physicians,improving precision & reducing times between video collection & completed score.
Right ventricular volume characteristics in ventricular septal defect.
Authors: T PGraham, G FAtwood, R JBoucek, DCordell, R CBoerth
Journal: Circulation (1976)

Right and left ventricular volume characteristics were determined from biplane cineangiocardiography in 37 patients with isolated ventricular septal defects. Patients were divided into three categories as determined by the degree of left-to-right shunt: small shunt-less than 35% of pulmonary blood flow (N=9); moderate shunt-35-49% (N=8), and large shunt-greater than 50% (N=20). Right ventricular (RV) end-diastolic volume was increased above normal in 15 of 20 studies performed in patients with large left-to-right shunts and averaged 159 +/- 10% of normal (P less than 0.001). In contrast, only one of the patients in the small shunt group and only half of the patients in the moderate shunt group showed increases in RV end-diastolic volume. The increase in RV volume was proportional to the corresponding increase in left ventricular end-diastolic volume, with the right ventricle ranging from 48 to 116% of LV end-diastolic volume (average 83%). Right ventricular ejection fraction was normal in all patient grou...
Energy conversion efficiency in human left ventricle.
Authors: TKameyama, HAsanoi, SIshizaka, KYamanishi, MFujita, SSasayama
Journal: Circulation (1992)

BACKGROUNDLeft ventricular mechanical efficiency is one of the most important measures of left ventricular pump performance. Several clinical studies, however, have shown that mechanical efficiency does not fall substantially as the heart fails. To clarify the insensitivity of mechanical efficiency to the change in pump performance, we analyzed human left ventricular mechanical efficiency, applying the concept of left ventricular systolic pressure-volume area (PVA).METHODS AND RESULTSPVA correlates linearly with myocardial oxygen consumption per beat (MVO2): MVO2 = a.PVA+b, and represents the total mechanical energy of contraction. We determined MVO2-PVA relation and external work in 11 patients with different contractile states. We also calculated the energy transfer from MVO2 to PVA (PVA/MVO2 efficiency), that from PVA to external work (work efficiency), and mechanical efficiency (external work/MVO2). Left ventricular pressure-volume loops were constructed by plotting the instantaneous left ventricular ...
TCTAP C-112 Trans Catheter Aortic Valve Replacement in the Presence of Starr-Edward Prosthesis in Mitral Position Using Balloon Expandable Prosthesis - Technical Challenges
Authors: Karthik Raghuram, Bijulal Sasidharan, Ankur Agarwal, Nishant Gangil
Journal: Journal of the American College of Cardiology (2021)
Pseudomonas aeruginosa and whirlpools.
Authors: J Brett, A du Vivier
Journal: BMJ (1985)

over will be the equivalent of a cut to about 7-2 beds per 1000 elderly population over the next 15 years.To achieve a norm of 8 5 beds by the year 2000 would require all geriatric units to start with a norm of 10 beds now.The hard facts are that more funding, for both hospital and local authority social services, is required merely to maintain the already inadequate level of care as the population of very old people increases.
Morphological, biochemical, and electrophysiological characterization of a clonal cell (H9c2) line from rat heart.
Authors: JHescheler, RMeyer, SPlant, DKrautwurst, WRosenthal, GSchultz
Journal: Circulation Research (1991)

Morphological, electrophysiological, and biochemical properties of H9c2 cells, a permanent cell line derived from rat cardiac tissue, were studied. Although the lectin binding pattern revealed similar sugar residues in the surface coat of H9c2 cells and isolated rat cardiocytes, heart-specific morphological structures could not be detected in H9c2 cells. Under physiological ionic conditions, H9c2 cells exhibited an outwardly rectifying, transient K+ current. When this current component was blocked by Ba2+ and Cs+, we observed an inward current through Ca2+ channels (15.8 +/- 2.2 pA/pF, n = 18, measured as Ba2+ current) that showed all characteristics of cardiac L-type currents. The activation kinetics were fast, and the current was stimulated by isoproterenol. The effect of isoproterenol was mimicked by forskolin or intracellularly applied cAMP. In radioligand binding experiments, we identified a specific, saturable, stereoselective and reversible high-affinity [3H]-(+)PN 200-110 binding with a dissociati...
Ontogeny of blood pressure and the renin-angiotensin-aldosterone system. Sequential studies in the newborn lamb.
Authors: T AWilson, D LKaiser, E MWright, M JPeach, R MCarey
Journal: Circulation Research (1981)

To test the hypothesis that the rise in arterial pressure occurring with maturation is due to an increase in the vascular responsiveness to angiotensin II, sequential cumulative doses of angiotensin II were infused intravenously into chronically catheterized newborn lambs maintained on a constant, weight-adjusted sodium intake from birth to 8 weeks of age. Basal mean arterial pressure correlated with both age and weight, but age was a stronger determinant of mean arterial pressure than was weight. No change in the mean arterial pressure response to angiotensin II occurred with maturation. Basal plasma renin activity and plasma aldosterone concentrations were low and did not change significantly with age. Therefore, in the newborn lamb in the sodium replete state, age is a better determinant of arterial pressure than is weight. However, an age-related change in vasoconstrictor responsiveness to angiotensin II does not occur and, therefore, cannot account for the rise in arterial pressure that is observed w...