tbuckley/cabot-search huggingface dataset:
Nonuniformity of the transmural distribution of coronary blood flow during the cardiac cycle. In vivo documentation by contrast echocardiography.
Authors: DRovai, AL'Abbate, MLombardi, S ENissen, MMarzilli, ADistante, E MFerdeghini, A NDeMaria
Journal: Circulation (1989)

This study was performed to examine the transmural (endocardial vs. epicardial) heterogeneity of myocardial blood flow during the cardiac cycle (systole vs. diastole). Twenty-four contrast echocardiographic injections were performed in seven open-chest anesthetized dogs either into left anterior descending or circumflex coronary artery or into the aortic root. Two-dimensional echocardiography in short-axis view was performed and was digitized off-line into a 256 x 256 pixel matrix with 256 gray levels/pixel. All end-diastolic and end-systolic frames before and to peak contrast were analyzed. A region of interest corresponding to the most intensely opacified myocardial segment was traced, the mean videodensity measured, and the frame of initial contrast appearance detected. The region of interest was divided into three equal parallel layers corresponding to the endocardial, midcardial, and epicardial myocardium. When the echocardiographic contrast effect initially appeared in diastole, the increment in vid...
Echocardiographic assessment of left ventricular filling and septal and posterior wall dynamics in idiopathic hypertrophic subaortic stenosis.
Authors: M GSutton, A JTajik, D GGibson, D JBrown, J BSeward, E RGuiliani
Journal: Circulation (1978)

In order to study left ventricular function in idiopathic hypertrophic subaortic stenosis (IHSS), left ventricular echograms were analyzed by computer and compared with results in normal subjects. Systolic function was consistently normal or above normal even in the presence of severe diastolic abnormalities. Wide variation in diastolic function in IHSS allowed separation of patients into three groups on the basis of the left ventricular peak filling rate. Because of the severe septal hypertrophy and hypokinesia, peak left ventricular filling rate is predominantly determined by the rate of free wall thinning. Patients in group 1 had rapid left ventricular filling rates, those in group 2 had normal filling rates, and those in group 3 had slow filling rates. With reduction in left ventricular peak filling rate caused by impaired free wall thinning, there was progressive increase in 1) duration of the rapid filling phase, 2) delay of mitral valve opening, 3) asynchrony between septum and posterior wall, 4) i...
Mask Mandates, On-Premises Dining, and COVID-19
Authors: Gery P. Guy, Greta M. Massetti, Erin Sauber-Schatz
Journal: JAMA (2021)

This JAMA Insights Clinical Update from the CDC's COVID-19 Response Team discusses the association of changes in COVID-19 case rates and death rates with implementation of state-issued mask mandates and allowance of any on-premises restaurant dining.
Immediate and short-term hemodynamic effects of diltiazem in patients with hypertension.
Authors: CAmodeo, IKobrin, H OVentura, F HMesserli, E DFrohlich
Journal: Circulation (1986)

The immediate effects of intravenous diltiazem effects and short-term (4 weeks) of the oral drug on systemic and regional hemodynamics, cardiac structure, and humoral responses were evaluated by previously reported methods in nine patients with mild-to-moderate essential hypertension and in one patient with primary aldosteronism. Diltiazem was first administered in three intravenous doses of 0.06, 0.06, and 0.12 mg/kg, respectively; patients were then treated for 4 weeks with daily doses ranging from 240 to 360 mg (average 300 mg). Intravenous diltiazem immediately reduced mean arterial pressure (from 115 +/- 3 to 96 +/- 3 mm Hg; p less than .01) through a fall in total peripheral resistance index (from 37 +/- 3 to 23 +/- 2 U/m2; p less than .01) that was associated with an increase in heart rate (from 66 +/- 2 to 77 +/- 3 beats/min; p less than .01) and cardiac index (from 3.3 +/- 0.3 to 4.3 +/- 0.4 liters/min/m2; p less than .01). These changes were not associated with changes in plasma levels of catech...
Blood flow and in vivo apparent viscosity in working and non-working skeletal muscle of the dog after high and low molecular weight dextran.
Authors: LGustafsson, LAppelgren, H EMyrvold
Journal: Circulation Research (1981)

We studied the effect of high and low molecular weight dextran on blood flow and in vivo apparent viscosity in the vasodilated vascular bed of working and non-working skeletal muscle. In 12 mongrel dogs, the calf muscle of one hindlimb was isolated. Vasodilation was induced either by sciatic stimulation setting the muscle at rhythmic work or by intraarterial infusion of papaverine. Blood flow was measured electromagnetically at different perfusion pressures. In vivo apparent viscosity was calculated by comparing pressure-flow relationship for blood and a reference solution. Viscosity in vitro was determined in a cone-plate viscometer. A hyperviscous state was induced by intravenous infusion of high molecular weight dextran (HMWD). Hemodilution subsequently was produced by administration of low molecular weight dextran (LMWD). After HMWD, blood flow decreased to 30% of control values in the non-working group and to 45% of control values in the working group. After subsequent infusion of LMWD, blood flow re...
Heart rate modulates the disposition of neurally released norepinephrine in cardiac tissues.
Authors: YMasuda, M NLevy
Journal: Circulation Research (1985)

We determined the effect of heart rate on the disposition of neurally released norepinephrine from the cardiac tissues in open-chest, anesthetized dogs with complete atrioventricular block. After injecting desipramine to block the neuronal uptake of norepinephrine, we stimulated the cardiac sympathetic nerves supramaximally for about 3 minutes at a mean frequency of 2.7 Hz. In one series of experiments, we allowed coronary sinus blood flow to change spontaneously in response to cardiac pacing and sympathetic stimulation. The mean coronary sinus blood flows just before cessation of sympathetic stimulation were 67.4 +/- 4.2 (SE) and 37.4 +/- 2.7 ml/min during pacing at a high (150/min) and a low (60/min) frequency, respectively. The mean norepinephrine overflow into the coronary sinus blood during steady state sympathetic stimulation was 45.0 +/- 14.2% greater during high frequency pacing than during low frequency pacing. After cessation of neural stimulation, the norepinephrine overflow decayed more rapidl...
Abstract 10381: Variances of Cardiovascular Risk Factors Among Asian Subgroups, National Health Interview Survey 2014-2017
Authors: Murrium I Sadaf, Rohan Khera, Gowtham Grandhi, Salim S Virani, Khurram Nasir, Javier Valero-Elizondo
Journal: Circulation (2019)

Background: Atherosclerotic cardiovascular disease (ASCVD) is the leading cause of morbidity and mortality in the US. Asian subgroups are a heterogeneous population within the US with poorly unders...
Postmortem tissue digoxin concentrations in infants and children.
Authors: P WKim, R WKrasula, L FSoyka, A RHastreiter
Journal: Circulation (1975)

The concentrations of digoxin in tissues of premature infants, full-term infants and older children obtained at autopsy were determined by a radioimmunoassay procedure. Infants were found to have much higher concentrations in the right and left ventricle (about 190 ng/g) than older children (about 70 ng/g) and adults as reported in the literature. Renal concentrations were lower in the premature group which may be related to their limited excretory capacity for digoxin. The relatively high myocardial concentrations of digoxin found in this study suggest that the usually recommended doses for infants may be excessive.
Exercise performance after repair of anomalous origin of the left coronary artery from the pulmonary artery.
Authors: S MParidon, Z QFarooki, L RKuhns, EArciniegas, W WPinsky
Journal: Circulation (1990)

Eleven patients underwent exercise testing after operative repair of anomalous origin of the left coronary artery from the pulmonary artery. Five patients repaired after 2 years of age comprised a childhood surgery group, and six patients repaired before 2 years of age comprised an infant surgery group. All patients were exercised using either a treadmill or electronically braked bicycle with simultaneous thallium 201 scintigraphy. Oxygen consumption, carbon dioxide production, pulmonary functions, and electrocardiogram were all monitored continuously. Pulmonary reserve was normal in all patients. Based on heart rate reserve, respiratory exchange ratio, and oxygen-consumption response to work load, two patients in the infant surgery group stopped exercise before achieving maximum aerobic capacity. All remaining patients achieved their maximum aerobic capacity. There was no difference in work rate or oxygen consumption during exercise between the infant and childhood surgical group. Four patients (two in e...
From the authors
Authors: F. Lofaso, D. Orlikowski, J-C. Raphael
Journal: European Respiratory Journal (2007)

We would like to thank J.R. Bach and co-workers for their interest in our editorial. While we note their comments, our experience based on more than 500 neuromuscular patients, 60% of whom are receiving long-term noninvasive mechanical ventilation (NIMV) with manually and mechanically assisted coughing techniques 1 and 40% of whom are tracheostomised, differs from theirs.

NIMV is not always tolerated and does not avoid some severe complications, including acute respiratory failure followed by death, as observed by Toussaint et al. 2 despite their undoubted competency in the field.

Our intensive care unit experience allowed us to demystify tracheostomy and to reduce tracheostomy complications. …
Bioactive nanotherapeutic trends to combat triple negative breast cancer
Authors: Pallabita Chowdhury, Upasana Ghosh, Kamalika Samanta, Meena Jaggi, Subhash C. Chauhan, Murali M. Yallapu
Journal: Bioactive Materials (2021)

The management of aggressive breast cancer, particularly, triple negative breast cancer (TNBC) remains a formidable challenge, despite treatment advancement. Although newer therapies such as atezolizumab, olaparib, and sacituzumab can tackle the breast cancer prognosis and/or progression, but achieved limited survival benefit(s). The current research efforts are aimed to develop and implement strategies for improved bioavailability, targetability, reduce systemic toxicity, and enhance therapeutic outcome of FDA-approved treatment regimen. This review presents various nanoparticle technology mediated delivery of chemotherapeutic agent(s) for breast cancer treatment. This article also documents novel strategies to employ cellular and cell membrane cloaked (biomimetic) nanoparticles for effective clinical translation. These technologies offer a safe and active targeting nanomedicine for effective management of breast cancer, especially TNBC.
Lesion-to-lesion independence of restenosis after treatment by conventional angioplasty, stenting, or directional atherectomy. Validation of lesion-based restenosis analysis.
Authors: C MGibson, R EKuntz, MNobuyoshi, BRosner, D SBaim
Journal: Circulation (1993)

BACKGROUNDSince many restenosis trials include patients in whom more than one  is treated, analysis of the angiographic data on a per lesion basis might be confounded by potential correlations of restenosis among multiple treated lesions within each patient. The goals of this study were: 1) to determine whether there was any correlation in the rate of restenosis among multiple lesions that underwent conventional angioplasty, stenting, or directional atherectomy within the same patient and 2) to determine whether lesions treated in a multilesion intervention experience a different magnitude of restenosis than lesions undergoing single-lesion procedures.METHODS AND RESULTSOf 441 patients treated by Palmaz-Schatz stenting (n = 114), directional atherectomy (n = 100), or conventional balloon angioplasty (n = 227), 67 underwent multilesion procedures involving treatment of 146 lesions. A general linear model with intraclass correlation (GLIMIC) was used to calculate the coefficient of correlation (rho)...
Modified Shumacker repair of transposition of the great arteries.
Authors: J AWaldhausen, W SPierce, WBerman, VWhitman
Journal: Circulation (1979)

Seven infants weighing from 6.4 to 10.3 kg underwent correction of transposition of the great arteries by the venous transposition operation as described by Shumacker. In this operation, a new atrial septum is constructed using a bipedicled right atrial flap, and the lateral atrial wall is constructed using a viable pericardial flap. Three of the patients had an associated ventricular septal defect. Six of the seven patients survived and have had an excellent clinical result. Although atrial arrhythmias were common in the early postoperative period, all patients are now in sinus rhythm. Two patients have had postoperative cardiac catheterization and cineangiography, which showed excellent hemodynamic results. The modified Shumacker operation preserves two of the three internodal pathways, provides a compliant, viable atrial septum, and permits fabrication of a generous-size physiological left atrium. This appears to offer advantages not present in the Mustard procedure.
Effect of changing metabolic rate on local blood flow control in the canine hindlimb.
Authors: A HGoodman, REinstein, H JGranger
Journal: Circulation Research (1978)

This study examined the effect of changing hindlimb metabolic rate on hindlimb blood flow control in anesthetized dogs. The hyperemias induced by graded levels of arterial hypoxia and the degree of steady state autoregulation evoked by changes in blood pressure were measured. Metabolic rate was increased above the resting value by direct electrical stimulation of hindlimb muscles at rates from 0.5 to 1.5 pulses/second, and in three dogs was reduced by cooling. In response to 6 minutes of arterial hypoxia, hindlimb blood flow steadily increased. At rest, and at each level of muscle stimulation, the steepness of the response increased as arterial oxygen saturation (SAO2) decreased. At all levels of SAO2, the response was steeper at increasing stimulation rates. For SAO2 greater than 50%, the relationship between the percentage increase in blood flow from control and SAO2, however, was unaffected by the degree of muscle activity, suggesting that during mild to moderate hypoxia the dynamics of the response we...
Morphologic changes in the pulmonary arteries after percutaneous balloon angioplasty for pulmonary arterial stenosis.
Authors: B SEdwards, R VLucas, J ELock, J EEdwards
Journal: Circulation (1985)

The pathologic appearance of pulmonary arteries subjected to balloon dilation was studied in four subjects with stenosis of pulmonary arteries. Nine vessels were dilated. Successful dilation in seven vessels was accompanied by intimal disruption and tearing of the media. In one vessel, at the site of a previous surgical procedure, dilation could not be accomplished. Histologically, this vessel was encased by reactive fibrous tissue, which may have precluded successful dilation. In one case, simultaneous rupture of the dilating balloon and the left pulmonary artery occurred. Morphologic examination could not adequately explain the cause of vessel rupture. Among the six vessels successfully dilated and studied 4 to 14 months after the dilation, the postdilation luminal diamter had been maintained. Tears in the intima and media as seen histologically had been filled in by scar tissue. In one artery a dilated segment distal to a residual obstruction revealed marked intimal proliferation.
Load independence of the rate of isovolumic relaxation in man.
Authors: M RStarling, D GMontgomery, G BMancini, R AWalsh
Journal: Circulation (1987)

This investigation was designed to determine whether the rate of isovolumic left ventricular pressure decline is affected by load in man. Fourteen patients were instrumented with micromanometer left ventricular and right atrial pacing catheters to maintain a constant heart rate during control conditions and infusion of methoxamine or nitroprusside. The isovolumic relaxation period was defined as the time from peak (-)dP/dt to 5 mm Hg above left ventricular end-diastolic pressure of the following beat. The rate of isovolumic relaxation was calculated as time constants (Tau) from the linear regression of natural log pressure vs time (Tln) and instantaneous (-)dP/dt vs pressure (TD), which includes a variable asymptote (PB). The mean heart rates and average (+)dP/dt values normalized at 40 mm Hg development pressure (DP40) did not differ significantly, despite 33% and 43% increases in left ventricular peak and end-diastolic pressures during the infusion of methoxamine (p less than .001 and p less than .01, r...
The pressor effect of moderate alcohol consumption in man: a search for mechanisms.
Authors: P DArkwright, L JBeilin, RVandongen, I ARouse, CLalor
Journal: Circulation (1982)

Thirty pairs of drinking and nondrinking men, matched for age and weight, were drawn from a working population in which a close relationship between alcohol consumption and blood pressure had been demonstrated. In this smaller sample, men who drank an average of 408 ml of ethanol/week had higher supine (126.9 +/- 2.3 mm Hg) and standing (113.3 +/- 2.5 mm Hg) systolic and supine diastolic blood pressure (75.5 +/- 2.2 mm Hg) than nondrinkers (117.5 +/- 2.0, 107.4 +/- 2.2 and 68.9 +/- 1.8 mm Hg, respectively). Resting plasma concentrations of free and sulfated norepinephrine and epinephrine, renin activity, angiotensin II, aldosterone and cortisol were similar in drinkers and nondrinkers. To investigate differences that may arise when sympathoadrenal activity was stimulated, the subjects underwent a series of standardized physiologic stresses: isometric hand grip, mental arithmetic, cold pressor testing, standing and bicycle exercise. Blood pressure and heart rate responses were similar in drinkers and nondr...
Direct in vivo gene transfer into porcine myocardium using replication-deficient adenoviral vectors.
Authors: B AFrench, WMazur, R SGeske, RBolli
Journal: Circulation (1994)

BACKGROUNDEfficient methods of introducing genes into myocardial cells must be developed before local somatic cell gene therapy can be implemented against myocardial disease. Although adenoviral (Ad5) vectors have been used to target rodent hearts and plasmid DNA has been directly injected into the myocardium of rats and dogs, the amounts of recombinant protein produced by these procedures have not been reported, and adenoviral vectors have not been used in large mammalian hearts.METHODS AND RESULTSReplication-deficient recombinant adenoviral vectors carrying either the luciferase or lacZ reporter genes were injected directly into the ventricular myocardium of adult domestic swine for evaluation of reporter gene expression. This procedure did not affect regional myocardial function as assessed by systolic wall thickening using ultrasonic crystals. Luciferase activity was detected 3 days after injection, increased markedly at 7 days, and then declined progressively at 14 and 21 days. Luciferase production ...
Effects of hypoxia, hyperkalemia, and metabolic acidosis on canine subendocardial action potential conduction.
Authors: R DVeenstra, R WJoyner, R TWiedmann, M LYoung, R CTan
Journal: Circulation Research (1987)

We have studied the individual and combined effects of elevated external potassium concentration (8 mM [K+], metabolic acidosis (pH = 6.8), and hypoxia at different stimulation 400 milliseconds) on Purkinje (P) and ventricular (V) conduction velocities and on Purkinje-ventricular junctional conduction delay (PVJ delay) in in vitro preparations from canine ventricles. Elevated [K+] had opposite effects on P and V velocities, increasing V velocity by 8% while reducing P velocity by 7%. Acidosis reduced P velocity by 9% while reducing V velocity by only 4%. Hypoxia and rapid stimulation rates had no significant effect on either P or V velocities. All test solutions (except hypoxia alone) significantly increased the PVJ delay. The magnitude of the increase in PVJ delay was much greater than the effects on either P or V velocity. In addition, hypoxia and rapid stimulation augmented the increase in PVJ delay in the presence of elevated [K+] and/or acidosis. The special features of conduction at the PV junctiona...
Urine temperature and core temperature
Authors: J. R. Ehrenkranz
Journal: JAMA (1986)

<h3>In Reply.—</h3> The selection of our urine temperature-measuring device was based on a number of factors. The first was ease of use by geriatric patients in a community setting. The mercury-in-glass thermometer is used widely and requires little instruction to be given to the patient. The second was comparability with the funneling device used in the British National Survey. A thorough scientific description of this apparatus was published by Fox et al.<sup>1</sup>Our project merely increased the minimum requirement of urine volume, which we assumed would result in greater specificity. Dr Ehrenkranz' criticisms illustrate the very problem we had with the British National Survey; namely, by a minor modification in the urine-collecting apparatus we were able to "eliminate" the prevalence of low (&lt;35.5 °C) temperature readings. The fact that these readings approximated rectal temperature reinforces our notion that chronic geriatric hypothermia may be a result of artifactual readings obtained
Standalone Performance of a New Integrated CADE/CADX System&amp;NBSP;For Detection and Characterization Of Colorectal Neoplasia
Authors: G Antonelli, A Repici, J Weigt, A Afifi, L Kliegis, C Hassan, H Neumann
Journal: Endoscopy (2021)

Aims Artificial Intelligence (AI) may reduce miss rate of colorectal neoplasia at colonoscopy by improving lesion recognition (CADe), and it may also reduce the cost of pathology by improving optical diagnosis (CADx).
Agreement in human interpretation of analog thallium myocardial perfusion images.
Authors: J EAtwood, DJensen, VFroelicher, KWitztum, KGerber, EGilpin, WAshburn
Journal: Circulation (1981)

To assess the agreement of human interpretation of analog thallium myocardial perfusion images, four experienced interpreters evaluated 100 images on two occasions using a form designed to limit reader variability. A high intraobserver agreement (agreement by same observer at separate times) of 89--93% was found when films were interpreted as normal or abnormal (a dichotomous decision). Interobserver agreement for a majority grouping of observers (three or four) was 75% for an abnormal and 68% for a normal interpretation. However, agreement ranged from 11--79% when interpreters were asked to read the anatomic location of defects. Posterior and lateral wall defects were interpreted with the least amount of agreement. These results indicate that caution must be taken when interpreting defect location. Using a scale of 1--10 to grade the severity of a defect, correlations of 0.82--0.86 were found when reading defects in the lateral and anterior projections. Higher correlations, from 0.86--0.94, were found in...
Effects of the COVID-19 pandemic on maternal and perinatal outcomes: a systematic review and meta-analysis
Authors: Barbara Chmielewska, Imogen Barratt, Rosemary Townsend, Erkan Kalafat, Jan van der Meulen, Ipek Gurol-Urganci, Pat O'Brien, Edward Morris, Tim Draycott, Shakila Thangaratinam, Kirsty Le Doare, Shamez Ladhani, Peter von Dadelszen, Laura Magee, Asma Khalil
Journal: The Lancet Global Health (2021)

The COVID-19 pandemic has had a profound impact on health-care systems and potentially on pregnancy outcomes, but no systematic synthesis of evidence of this effect has been undertaken. We aimed to assess the collective evidence on the effects on maternal, fetal, and neonatal outcomes of the pandemic.