tbuckley/cabot-search huggingface dataset:
Multiple regional differences in cellular properties that regulate repolarization and contraction in the right atrium of adult and newborn dogs.
Authors: M SSpach, P CDolber, P AAnderson
Journal: Circulation Research (1989)

Recent studies of isolated cardiac myocytes have generated the need for detailed information about regional electrophysiological differences in the atrium. We measured the spatial distribution of action potentials in adult and newborn canine right atria. Multiple regional differences in action potential shape and duration were found. The multiple regional differences produced an overall simple pattern: the longest action potentials occurred in the area of the sinus node, and the action potential duration decreased with increasing distance from the sinus node area. To account for the overall pattern, we tested factors considered important in causing atrial action potential shape differences (e.g., electronic interactions). None of the factors tested accounted for the regional differences. We then found regional differences in the responses to pauses, which suggested that differences in the properties of individual cells accounted for the regional repolarization differences. If so, genetic regulation of the...
Cross-sectional echocardiographic diagnosis and subclassification of univentricular hearts: imaging studies of atrioventricular valves, septal structures and rudimentary outflow chambers.
Authors: D JSahn, J RHarder, R MFreedom, W JDuncan, R DRowe, H DAllen, LValdes-Cruz, S JGoldberg
Journal: Circulation (1982)

We reviewed anatomic observations (surgical or autopsy), angiograms and echocardiograms from 44 patients with documented univentricular hearts. Thirty-three patients had univentricular heart of left ventricular type with an outflow or rudimentary chamber. Five had univentricular heart of right ventricular type, and six had univentricular heart of indeterminate types without a rudimentary chamber. Univentricular heart was correctly diagnosed by two-dimensional echocardiography in all but two of the 44 patients, including 25 of 27 double-inlet univentricular hearts, all five with absent left and all 12 with absent right atrioventricular connection. One of the two blind trabecular pouches was missed on echocardiography; the other was not seen on the angiogram but was present at autopsy. In 30 of 33 patients, univentricular heart of left ventricular type was correctly identified by imaging an anterosuperior and leftward or rightward outlet chamber, and in four of five patients with univentricular heart of rig...
Effects of a cardiac glycoside on regional function, blood flow, and electrograms in conscious dogs with myocardial ischemia.
Authors: S FVatner, HBaig, W TManders, P AMurray
Journal: Circulation Research (1978)

We studied the effects of coronary occlusion and of subsequent ouabain administration on regional myocardial function, flow, and electrograms in 14 conscious dogs. Coronary occlusion resulted in a graded loss of regional function as reflected by measurements of segment length (SL), velocity of SL shortening and myocardial work from the normal to severely ischemic zones, along with graded flow (radioactive microsphere technique) reductions and graded elevation of the regional S-T segment. Ouabain, 20 microgram/kg, improved function in the normal zone, in which stroke shortening rose by 0.23 +/- 0.07 mm (mean +/- SE) and work rose by 30.2 +/- 9.5 mm Hg-mm. In moderately ischemic segments, stroke shortening rose by 0.60 +/- 0.05 mm and work rose by 58.1 +/- 6.1 mm Hg-mm. In the majority of severely ischemic segments, stroke shortening and work also increased; the average effect in all severely ischemic segments was an increase in stroke shortening of 0.35 +/- 0.10 mm and in work of 31.5 +/- 9.9 mm ...
Motion of the interatrial septum in acute mitral regurgitation. Clinical and experimental echocardiographic studies.
Authors: CTei, HTanaka, SNakao, HYoshimura, SMinagoe, TKashima, TKanehisa
Journal: Circulation (1980)

The interatrial septal echocardiograms from 15 patients with acute mitral regurgitation due to ruptured chordae tendineae were compared with those from 14 normal subjects. On the cross-sectional echocardiogram, the interatrial septal configuration in patients with chordal rupture showed a characteristic pattern in which the interatrial septum (IAS) was flat or slightly convex toward the left atrium at end-diastole and became markedly convex toward the right atrium at end-systole. On the M-mode echocardiogram, the interatrial septal amplitude was greater in patients with chordal rupture (12.4 +/- 1.9 mm) than in normal subjects (9.4 +/- 0.9 mm). Systolic fluttering of the IAS was found in five of 10 patients with rupture of the chordae attached to the posterior mitral leaflet. This finding was thought to be specific for acute mitral regurgitation due to ruptured chordae to the posterior mitral leaflet. After operation, the amplitude of the IAS became normal or diminished and systolic fluttering of the IAS ...
Appropriate Use of Short-Course Antibiotics in Common Infections: Best Practice Advice From the American College of Physicians
Authors: Rachael A. Lee, Robert M. Centor, Linda L. Humphrey, Janet A. Jokela, Rebecca Andrews, Amir Qaseem
Journal: Annals of Internal Medicine (2021)

Description: Antimicrobial overuse is a major health care issue that contributes to antibiotic resistance. Such overuse includes unnecessarily long durations of antibiotic therapy in patients with common bacterial infections, such as acute bronchitis with chronic obstructive pulmonary disease (COPD) exacerbation, community-acquired pneumonia (CAP), urinary tract infections (UTIs), and cellulitis. This article describes best practices for prescribing appropriate and short-duration antibiotic therapy for patients presenting with these infections. Methods: The authors conducted a narrative literature review of published clinical guidelines, systematic reviews, and individual studies that addressed bronchitis with COPD exacerbations, CAP, UTIs, and cellulitis. This article is based on the best available evidence but was not a formal systematic review. Guidance was prioritized to the highest available level of synthesized evidence. Best Practice Advice 1: Clinicians should limit antibiotic treatment duration to 5 days when managing patients with COPD exacerbations and acute uncomplicated bronchitis who have clinical signs of a bacterial infection (presence of increased sputum purulence in addition to increased dyspnea, and/or increased sputum volume). Best Practice Advice 2: Clinicians should prescribe antibiotics for community-acquired pneumonia for a minimum of 5 days. Extension of therapy after 5 days of antibiotics should be guided by validated measures of clinical stability, which include resolution of vital sign abnormalities, ability to eat, and normal mentation. Best Practice Advice 3: In women with uncomplicated bacterial cystitis, clinicians should prescribe short-course antibiotics with either nitrofurantoin for 5 days, trimethoprim–sulfamethoxazole (TMP–SMZ) for 3 days, or fosfomycin as a single dose. In men and women with uncomplicated pyelonephritis, clinicians should prescribe short-course therapy either with fluoroquinolones (5 to 7 days) or TMP–SMZ (14 days) based on antibiotic susceptibility. Best Practice Advice 4: In patients with nonpurulent cellulitis, clinicians should use a 5- to 6-day course of antibiotics active against streptococci, particularly for patients able to self-monitor and who have close follow-up with primary care.
Nanoarchitectures for efficient IgE cross‐linking on effector cells to study amoxicillin allergy
Authors: Amene Tesfaye, Alba Rodríguez‐Nogales, Sara Benedé, Tahía D. Fernández, Juan L. Paris, Maria J. Rodriguez, Isabel M. Jiménez‐Sánchez, Gador Bogas, Cristobalina Mayorga, María J. Torres, María I. Montañez
Journal: Allergy (2021)

Amoxicillin (AX) is nowadays the β-lactam that more frequently induces immediate allergic reactions. Nevertheless, diagnosis of AX allergy is occasionally challenging due to risky in vivo tests and non-optimal sensitivity of in vitro tests. AX requires protein haptenation to form multivalent conjugates with increased size to be immunogenic. Knowing adduct structural features for promoting effector cell activation would help to improve in vitro tests. We aimed to identify the optimal structural requirement in specific cellular degranulation to AX using well-precised nanoarchitectures of different lengths.We constructed eight Bidendron Antigens (BiAns) based on polyethylene glycol (PEG) linkers of different lengths (600-12,000 Da), end-coupled with polyamidoamine dendrons that were terminally multi-functionalized with amoxicilloyl (AXO). In vitro IgE recognition was studied by competitive radioallergosorbent test (RAST) and antibody-nanoarchitecture complexes by transmission electron microscopy (TEM). Their allergenic activity was evaluated using bone marrow-derived mast cells (MCs) passively sensitized with mouse monoclonal IgE against AX and humanized RBL-2H3 cells sensitized with polyclonal antibodies from sera of AX-allergic patients.All BiAns were recognized by AX-sIgE. Dose-dependent activation responses were observed in both cellular assays, only with longer structures, containing spacers in the range of PEG 6000-12,000 Da. Consistently, greater proportion of immunocomplexes and number of antibodies per complex for longer BiAns were visualized by TEM.BiAns are valuable platforms to study the mechanism of effector cell activation. These nanomolecular tools have demonstrated the importance of the adduct size to promote effector cell activation in AX allergy, which will impact for improving in vitro diagnostics.
Mechanism of beneficial effect of beta-adrenergic blockade on exercise-induced myocardial ischemia in conscious dogs.
Authors: B DGuth, GHeusch, RSeitelberger, JRoss
Journal: Circulation Research (1987)

We examined the importance of decreased heart rate in the beneficial effect of beta-adrenergic blockade on exercise-induced regional myocardial ischemia and contractile dysfunction in conscious dogs with single vessel coronary stenosis (ameroid constrictor). Studies were performed during control treadmill exercise, which produced regional myocardial ischemia (blood flow measured with microspheres) and wall dysfunction (measured using sonomicrometers). A second run was performed after the administration of atenolol (0.3-1.0 mg/kg i.v.), and the reduced heart rate caused by atenolol during early steady-state running was then prevented by atrial pacing during the latter portion of the run. Atenolol reduced the exercise heart rate from 217 +/- 25 beats per minute (SD, n = 9) to 166 +/- 15, and ischemic zone wall thickening during systole improved from 27 +/- 22% of the resting value in the control run to 50 +/- 25% of the resting value in the atenolol run (p less than 0.01). Atrial pacing then increased heart...
Subclavian arterioplasty for the ipsilateral subclavian-to-pulmonary artery shunt.
Authors: HLaks, WWilliams, GTrusler, ACastaneda
Journal: Circulation (1979)

A new technique is described to avoid kinking and improve flow in the ipsilateral subclavian-to-pulmonary artery shunt. Experience with this procedure is reviewed in 35 infants and children with a variety of cyanotic congenital heart disease, including 10 with tricuspid atresia. Of these, 17 had had previous shunts: a Waterston shunt in six, a Glenn shunt in six, and a contralateral Blalock-Taussig shunt in five. The mean age was 5.6 years (range, 1 day to 16 years), and the mean follow-up was 24 months (range, 11 months to 4.5 years). There were no early deaths (less than 30 days), but there were two late deaths. There were three shunt failures at 2 weeks, 1 month, and 10 months; two of the failures were in infants aged 1 day and 4 days at operation. There were no late shunt failures. The patency by the life table method was 91.4% at 6 months, 88.5% at 1 year, with no further drop-off. It is concluded that subclavian arterioplasty can be performed safely and offers improved shunt patency in comparing to ...
Intracoronary versus intravenous effects of cocaine on coronary flow and ventricular function.
Authors: H JZimring, R LFitzgerald, R LEngler, B RIto
Journal: Circulation (1994)

BACKGROUNDCocaine use has been associated with cardiomyopathy and ischemic coronary syndromes. However, the pathophysiological mechanisms responsible for these syndromes are not clear and have been suggested to involve direct effects of cocaine on myocyte contractility and coronary resistance as well as indirect effects via altered autonomic tone, secondary mediators, and myocardial metabolism. We sought to distinguish direct from indirect effects of cocaine on ventricular function and coronary resistance by comparison of the administration of intracoronary cocaine (0.12 to 0.36 mg/min constant infusion) with intravenous cocaine (5 mg/kg bolus infusion) in an in vivo anesthetized pig preparation.METHODS AND RESULTSTo control for changes in coronary resistance secondary to autoregulation and myocardial metabolism, the left anterior descending coronary artery was perfused at constant coronary pressure and the interventricular vein was cannulated for coronary venous oxygen saturation measurement. Coronary bl...
Abstract 15193: Racial Difference in Clinical and Epidemiological Characteristics of Kawasaki Disease in Southeast US
Authors: Luz A Padilla, Jacqueline L Collins, Adeniyi J Idigo, Yung R Lau, Michael A Portman, Sadeep Shrestha
Journal: Circulation (2019)

Introduction: Kawasaki Disease (KD) displays substantial variation in prevalence and response to intravenous gamma globulin (IVIG) by race and ethnicity. However, studies including and making concl...
Oxygen consumption and coronary reactivity in postischemic myocardium.
Authors: D DLaxson, D CHomans, X ZDai, ESublett, R JBache
Journal: Circulation Research (1989)

Coronary vascular responses in regions of reversible postischemic myocardial contractile dysfunction (stunned myocardium) were examined in chronically instrumented, awake dogs. Left anterior descending coronary artery blood flow and oxygen extraction, aortic and left ventricular pressures, and regional myocardial segment shortening were determined. Regional myocardial blood flow was measured with microspheres. Coronary reactive hyperemia and vasodilator reserve, and regional myocardial oxygen consumption were determined. Three sequential 10-minute left anterior descending coronary artery occlusions separated by 30-minute reperfusion periods resulted in progressive postischemic dysfunction so that 1 hour after the final coronary artery occlusion, myocardial segment shortening was reduced to 37% of baseline. Despite this decrease in contractile function, left anterior descending artery flow (19.6 +/- 2.6 vs. 18.4 +/- 3.0 ml/min), myocardial blood flow and the transmural distribution of flow measured with mi...
Glucose and palmitate oxidation in isolated working rat hearts reperfused after a period of transient global ischemia.
Authors: G DLopaschuk, M ASpafford, N JDavies, S RWall
Journal: Circulation Research (1990)

Alterations in energy substrate utilization during reperfusion of ischemic hearts can influence the functional recovery of the myocardium. Energy substrate preference by the reperfused myocardium, however, has received limited attention. Therefore, we measured oxidation rates of glucose and palmitate during reperfusion of ischemic hearts. Isolated working rat hearts were perfused with 1.2 mM palmitate and 11 mM [14C]glucose, 1.2 mM [14C]palmitate and 11 mM glucose, or 11 mM [14C]glucose alone, at an 11.5 mm Hg preload and 80 mm Hg afterload. Hearts were subjected to 60-minute aerobic perfusion or 25-minute global ischemia followed by 60-minute aerobic reperfusion. Steady-state oxidative rates of glucose or palmitate were determined by measuring 14CO2 production. In hearts perfused with glucose alone, oxidative rates during reperfusion were not significantly different than nonischemic hearts (1,008 +/- 335 vs. 1,372 +/- 117 nmol [14C]glucose oxidized/min/g dry wt, respectively). In the presence of palmitat...
Patients with evidence of coronary endothelial dysfunction as assessed by acetylcholine infusion demonstrate marked increase in sensitivity to constrictor effects of catecholamines.
Authors: J AVita, C BTreasure, A CYeung, V IVekshtein, G MFantasia, R DFish, PGanz, A PSelwyn
Journal: Circulation (1992)

BACKGROUNDStudies in patients undergoing cardiac catheterization have demonstrated that normal coronary arteries dilate and atherosclerotic arteries constrict in response to exercise and the cold pressor test, but the mechanisms are unknown. These vasomotor responses are mirrored by the vasomotor response to the endothelium-dependent agent acetylcholine. Exercise and the cold pressor test are associated with adrenergic stimulation and increased circulating catecholamines. The present study tested the hypothesis that coronary arteries with intact endothelial function are relatively resistant to the constrictor effects of catecholamines, whereas arteries with loss of endothelial function have increased sensitivity to catecholamine-induced constriction.METHODS AND RESULTSThe vasomotor function of the coronary endothelium was assessed by serial acetylcholine infusions (final concentration, 10(-8) to 10(-6) M) in 30 segments in 15 patients with minimal or no evidence of coronary atherosclerosis. The acetylchol...
Long-term prognosis of patients with variant angina.
Authors: AWalling, D DWaters, D DMiller, DRoy, G BPelletier, PThéroux
Journal: Circulation (1987)

The long-term prognosis of variant angina and the factors influencing it were assessed in 217 consecutive patients hospitalized in our coronary care unit and followed for a mean of 65 months (range 2 to 123). Cardiac death occurred in 30 patients and an additional 54 experienced a nonfatal myocardial infarction. Survival at 1 and 5 years was 95% and 89%, respectively; survival without infarction was 83% and 69%. Coronary disease and the degree of disease activity were strong predictors of survival by Cox analysis. Survival at 1 year was 99%, and that at 5 years was 95% and 94%, respectively, for patients with one-vessel disease (n = 81) and for those without stenoses of 70% or greater (n = 87). Survival at 1 and 5 years was only 87% and 77% for those with multivessel disease (n = 40). The Cox analysis selected left ventricular function, initial treatment, extent score, duration of angina at rest, and disease activity as multivariate predictors of survival without infarction. Coronary disease was a strong ...
The Diagnosis and Treatment of Pulmonary Tuberculosis.
Journal: Annals of Internal Medicine (1947)

The importance of early diagnosis in what is sometimes called the prebacillary stage of tuberculosis is most strongly emphasized in this work. On this subject the author writes: "If medical men in general would expend in learning to diagnose tuberculosis early but a fraction of the energy that a few scientists are expending in endeavoring to discover a 'cure,' we would be able to say that the cure for tuberculosis is already at hand." "Early diagnosis must be made independent of the microscope." Chapters III and IV, devoted to general rules for examination and details in the diagnosis of early tuberculosis, are worthy of careful study. That early diagnosis is of the greatest importance none will deny and we are almost if not quite prepared to take the author's position that late diagnosis is proof of professional carelessness or incapacity. The subjects of prophylaxis, diet and treatment are thoroughly marked
Preservation of endothelium-dependent vascular relaxation in cholesterol-fed rabbit by treatment with the calcium blocker PN 200110.
Authors: J BHabib, CBossaller, CWilliams, J DMorrisett, P DHenry
Journal: Circulation Research (1986)

We tested the effects of low doses of a dihydropyridine calcium antagonist, PN 200110, on endothelium-dependent vascular relaxation in rabbits fed a 1% cholesterol diet. The drug was given orally, 1 mg/day, and control rabbits received placebo. Plasma total cholesterol after 10 weeks, was similar in the placebo- and PN 200110-treated groups. The respective values averaged 2140 +/- 116 (n = 14; mean +/- SEM) and 2012 +/- 115 mg/dl (n = 13). In placebo-treated rabbits, sudanophilic aortic lesions covered 52 +/- 5% of the intimal surface, and the aortic cholesterol concentration was 72 +/- 6 mg/g protein. Corresponding values in aortas from PN 200110-treated rabbits were significantly lower [36 +/- 5% (P less than 0.03) and 52 +/- 3 mg/g protein (P less than 0.03)]. Maximal endothelium-dependent cholinergic relaxation of aortic strips in untreated (n = 14) and treated cholesterol-fed rabbits (n = 13) differed significantly (P less than 0.01) and averaged 31 +/- 4% and 61 +/- 7% of the value in normocholester...
The Anticipation and Treatment of Post Partum Haemorrhage
Authors: D. de Berdt Hovell
Journal: BMJ (1873)

6oi difficult to transfer the pressure to the aorta, a proceeding which I have often seen of great service; then cold may be added as an excellent assistant to pressure; in certain cases, opium is a valuable remedy.The precise position which a solution of the perchloride of iron will occupy in the future I cannot tell; it has not, in my hands, appeared to be so innocent an agent as, from what has been written about it, I had sup- posed; but, as my experience has been limited, I give no decided opinion.
Improvement of glucose tolerance and lowering of glycohemoglobin and serum lipid concentrations after discontinuation of antihypertensive drug therapy.
Authors: R PAmes, PHill
Journal: Circulation (1982)

Diuretic-based antihypertensive drug therapy causes a disturbance in glucose tolerance and in serum lipid and lipoprotein concentrations. To determine the reversibility of the glucose intolerance and to identify mechanisms of the metabolic alterations, we examined a short glucose tolerance test and insulin, glycohemoglobin and lipid concentrations during the supervised withdrawal of long-term drug therapy in 35 patients with primary hypertension. An average of 7 weeks after stopping drugs, glucose tolerance and glycohemoglobin improved, total cholesterol decreased 18 mg/dl, triglyceride decreased 27 mg/dl, and the ratio of total to high-density lipoprotein cholesterol decreased (p less than 0.01 for all variables vs treatment values). The changes in lipid concentrations from the treated to untreated state correlated with the changes in glycohemoglobin and indexes of glucose metabolism. The findings suggest that insulin resistance develops during drug therapy and disturbs both glucose and lipid metabolism....
A study of the dynamic relations between the mitral valve echogram and phasic mitral flow.
Authors: SLaniado, EYellin, MKotler, LLevy, JStadler, RTerdiman
Journal: Circulation (1975)

Echocardiographically recorded mitral valve motion was compared with phasic transmitral flow in 17 open chest dogs. The normal mitral valve opening started with the onset of mitral flow and reached its full excursion while flow was still accelerating. Complete valve opening occurred .044 sec (plus or minus .002 sem) before peak flow, during which time an average of 17.6 percent of total mitral filling volume had passed through the valve. In contrast to the opening movement, the closing motion of the anterior mitral valve cusp lagged behind the deceleration of mitral flow. The E-F phase of the mitral valve echogram started while mitral flow was still increasing and resulted from a combined posterior motion of the cusp and the ring. The E-F slope of the normal valve was found to decrease with reduced cardiac output. The amplitude of the anterior cusp excursion did not reflect the amount of mitral flow. Prolonged P-R interval may induce a mid-diastolic reversal of mitral flow which, in turn, may be accompani...