tbuckley/cabot-search huggingface dataset:
Isoproterenol-induced alterations in myocardial blood flow, systolic and diastolic function in conscious dogs with heart failure.
Authors: LHittinger, R PShannon, SKohin, A SLader, W TManders, T APatrick, PKelly, S FVatner
Journal: Circulation (1989)

The effects of isoproterenol were examined in 10 conscious, chronically instrumented adult dogs with left ventricular (LV) failure after pressure overload hypertrophy induced by aortic banding at 8-10 weeks of age (LV free wall plus septum-to-body weight ratio, 8.6 +/- 0.5 g/kg) and also in eight control dogs (LV free wall plus septum-to-body weight ratio, 5.1 +/- 0.3 g/kg). Baseline values of heart rate, LV end-diastolic pressure, LV end-diastolic stress, and LV systolic wall stress were greater in the LV failure dogs (p less than 0.01), whereas the ejection phase index, rate of change of LV short-axis diameter, LV dD/dt, was depressed compared with control animals. In the control animals, isoproterenol infusion increased Vcf and LV dD/dt significantly (p less than 0.05), whereas LV systolic wall stress did not change. In the LV failure dogs, the increases in Vcf and LV dD/dt were less (p less than 0.01), and LV systolic wall stress increased (p less than 0.01). In the control animals, LV end-diastolic p...
Recent Advances in Epigenetic Biomarkers and Epigenetic Targeting in Prostate Cancer
Authors: Anbarasu Kumaraswamy, Katherine R. Welker Leng, Thomas C. Westbrook, Joel A. Yates, Shuang G. Zhao, Christopher P. Evans, Felix Y. Feng, Todd M. Morgan, Joshi J. Alumkal
Journal: European Urology (2021)
Impact of Interventional Biliary EUS (EUS-BD) on Outcomes of Biliary Drainage in a Tertiary Care Setting
Authors: V Dhir, P Udawat, R Shah
Journal: Endoscopy (2021)

Aims To assess whether EUS-BD has affected the outcomes of biliary drainage in terms of success, adverse events, costs, and duration of hospitalization. The primary end point was rate of successful endoscopic drainage (ERCP+EUS-BD). The secondary endpoints were adverse events, duration of hospitalization, and procedure costs related to secondary procedures.
High alpha 1-adrenoceptor occupancy decreases relaxing potency of nifedipine by increasing myosin light chain phosphorylation.
Authors: P HRatz
Journal: Circulation Research (1993)

It has been proposed that the decreased potency of Ca2+ channel blockers to produce relaxation in vascular tissues contracted at high alpha 1-adrenoceptor occupancy may be caused by activation of spare receptors. Results from the present study using isolated strips of rabbit renal arteries contracted with the alpha 1-adrenoceptor agonist phenylephrine (PhE) support this hypothesis and provide a cellular explanation for the phenomenon. PhE at 1 microM activated only 23% of the total alpha 1-adrenoceptor pool but produced maximum stress while increasing the extent of myosin light chain phosphorylation to 35%. Activation of additional (spare) alpha 1-adrenoceptors with 100 microM PhE produced an additional increase in the extent of myosin light chain phosphorylation, which reached 45%, but did not produce an additional increase in stress above that produced by 1 microM PhE. A complete [PhE]-response curve revealed a quasihyperbolic dependency of stress on myosin light chain phosphorylation; i.e., a roughly l...
Prevention of postischemic ventricular fibrillation late after right or left stellate ganglionectomy in dogs.
Authors: P EPuddu, RJouve, FLanglet, J CGuillen, MLanti, AReale
Journal: Circulation (1988)

To gain insight into the differences in antiarrhythmic potential of right vs left stellate ganglionectomy, 72 dogs were randomized to either unilateral stellectomy or second intercostal space thoracotomy and left circumflex coronary arteriovenous pedicle occlusion was performed, without vagotomy, a mean of 8 weeks later under anesthesia. The type and timing of ventricular ectopic beats, including both nonsustained and sustained ventricular tachycardia and ventricular fibrillation, were investigated. Several covariates, including postischemic electrocardiographic changes, were considered. Both right and left stellate ganglionectomy reduced the incidence of early (0 to 10 min) (p = .004 and p = .001, respectively) and total (0 to 60 min) (p = .009 and p = .008, respectively) ischemia-induced ventricular fibrillation, and improved outcome (p = .0013 and p = .0012, respectively). Early sustained ventricular tachycardia was similarly reduced (p = .02) in both stellectomized groups. By contrast, neither the typ...
Microinjection of antibodies and expression vectors into living myocardial cells. Development of a novel approach to identify candidate genes that regulate cardiac growth and hypertrophy.
Authors: H EShubeita, JThorburn, K RChien
Journal: Circulation (1992)

BACKGROUNDMicroinjection approaches in the cardiac cell context have allowed delivery of various calcium dyes and monitoring of short-term physiological responses. However, unlike other cell types, it has proved difficult to microinject myocardial cells without the concomitant loss of long-term cell viability.METHODS AND RESULTSAn analysis of experimental variables was conducted to adapt microinjection techniques to the neonatal rat ventricular cell context. Among the variables optimized were the selection of culture dishes, plating substrate, microinjection parameters, and a variety of maneuvers to inhibit myocyte hypercontracture, injury, and consequent death after micropuncture. With the modified technique, the percentage of injected cells that maintained long-term viability (48 hours) increased from less than 1% to 30%. Similarly, an increased efficiency of gene transfer and expression (measured as the percentage of injected cells that express the delivered gene) was obtained after either cytoplasmic ...
A prospective, randomized, double-blind, crossover study to compare the efficacy and safety of chronic nifedipine therapy with that of isosorbide dinitrate and their combination in the treatment of chronic congestive heart failure.
Authors: UElkayam, JAmin, AMehra, JVasquez, LWeber, S HRahimtoola
Journal: Circulation (1990)

We performed a prospective, randomized, double-blind, crossover study to compare the efficacy and safety of vasodilation with the calcium entry blocker nifedipine with that of isosorbide dinitrate (ISDN) and their combination as treatment for heart failure. Twenty-eight patients with New York Heart Association Functional class II or III chronic heart failure due to left ventricular systolic dysfunction were studied. All patients were maintained on a constant dose of digitalis and diuretics throughout the study. Eight weeks of therapy with nifedipine alone or in combination with ISDN resulted in a significantly higher incidence of heart failure deterioration necessitating hospitalizations and/or additional diuretics. Twenty-four percent of patients required hospitalization during nifedipine therapy and 26% required hospitalization during nifedipine-ISDN combination therapy in comparison to 0% requiring hospitalization during ISDN therapy alone. The total number of heart failure-worsening episodes was nine ...
Understanding the relationship between norovirus diversity and immunity
Authors: Lauren A. Ford-Siltz, Kentaro Tohma, Gabriel I. Parra
Journal: Gut Microbes (2021)

Human noroviruses are the most common viral cause of acute gastroenteritis worldwide. Currently, there are no approved vaccines or specific therapeutics to treat the disease. Some obstacles delaying the development of a norovirus vaccine are: (i) the extreme diversity presented by noroviruses; (ii) our incomplete understanding of immunity to noroviruses; and (iii) the lack of a robust cell culture system or animal model for human noroviruses. Recent advances in in vitro cultivation of norovirus, novel approaches applied to viral genomics and immunity, and completion of vaccine trials and birth cohort studies have provided new information toward a better understanding of norovirus immunity. Here, we will discuss the complex relationship between norovirus diversity and correlates of protection for human noroviruses, and how this information could be used to guide the development of cross-protective vaccines.
Practice Variation Exists In The Performance Of Per Oral Endoscopic Myotomy (Poem): Results Of An International Survey Of Poem Experts
Authors: H Awadie, M Ramchandani, Z Nabi, I Gralnek, N Reddy
Journal: Endoscopy (2021)

Aims POEM for the treatment of achalasia was introduced by Inuoe in 2010. Since then, POEM has been widely adopted internationally. However, until now, there are no international “guidelines” on best practices for POEM. We aimed to assess potential practice variations amongst international POEM experts.
Wall shear stress distribution in a model canine artery during steady flow.
Authors: R JLutz, J NCannon, K BBischoff, R LDedrick, R KStiles, D LFry
Journal: Circulation Research (1977)

The wall shear stress pattern was measured in a rigid plastic cast of a canine artery during steady flow by means of an electrochemical technique. The topographic distribution of shear stress is very nonuniform, with regions of high and low shear in close proximity. The steady shear stresses are highest at the leading edge of flow dividers and at the entrance regions to branch vessels. The shapes of the shear stress curves in the celiac branch are primarily a function of the ratio of branch flow to total aortic flow. However, the shapes of the shear stress curves in the adjacent anterior mesenteric branch remain the same for different anterior mesenteric branch flow ratios, although the shear increases with the branch flow ratio. An unstable pattern of flow separation and reattachment is found at the anterior mesenteric flow divider lip and remains localized to that region. A correlation is suggested between sites of high shear stress, extremes in the range of stress, and unstable stress patterns and site...
Colorectal Post-Polypectomy Syndrome – 15-Year Experience of a Tertiary Referral Center
Authors: M Costa, D Perdigoto, L Barreto, I Cunha, E Gravito-Soares, P Amaro, P Figueiredo
Journal: Endoscopy (2021)

Aims Post-polypectomy syndrome (PPS) is an uncommon complication of colonoscopic polypectomy using eletrocoagulation. It is defined as persistent abdominal pain post-intervention without free intestinal perforation. Little is known about risk factors. The aim of this study was to characterize the syndrome in a Portuguese tertiary referral center.
The influence of vagal afferents on the left ventricular contractile response to intracoronary administration of catecholamines in the conscious dog.
Authors: K WBarron, V SBishop
Journal: Circulation Research (1981)

We studied the effect of vagal afferents on the left ventricular contractile response (LVdP/dtmax) to administration of sympathomimetic amines into the left circumflex coronary artery in conscious dogs. The positive inotropic effects of bolus administration of epinephrine, norepinephrine, and isoproterenol were greater during bilateral vagal cold block (BVB) that in the control state with the vagi intact (P less than 0.001). The inotropic potentiation observed with BVB was not due to vagal efferent interruption, since parasympathetic efferent block with atropine did not potentiate the inotropic effects of intracoronary epinephrine (P greater than 0.05). BVB also potentiated the inotropic effects of constant intracoronary infusion of epinephrine (P less than 0.01). BVB alone had no significant effect on LVdP/dtmax; dtmax (P less than 0.05). We propose that the potentiation of the inotropic effects during BVB could result from either interruption of a vagal afferent-mediated negative feedback reflex and/or ...
Smooth muscle myosin heavy chain exclusively marks the smooth muscle lineage during mouse embryogenesis.
Authors: J MMiano, PCserjesi, K LLigon, MPeriasamy, E NOlson
Journal: Circulation Research (1994)

We cloned a portion of the mouse smooth muscle myosin heavy chain (SM-MHC) cDNA and analyzed its mRNA expression in adult tissues, several cell lines, and developing mouse embryos to determine the suitability of the SM-MHC promoter as a tool for identifying smooth muscle-specific transcription factors and to define the spatial and temporal pattern of smooth muscle differentiation during mouse development. RNase protection assays showed SM-MHC mRNA in adult aorta, intestine, lung, stomach, and uterus, with little or no signal in brain, heart, kidney, liver, skeletal muscle, spleen, and testes. From an analysis of 14 different cell lines, including endothelial cells, fibroblasts, and rhabdomyosarcomas, we failed to detect any SM-MHC mRNA; all of the cell lines induced to differentiate also showed no detectable SM-MHC. In situ hybridization of staged mouse embryos first revealed SM-MHC transcripts in the early developing aorta at 10.5 days post coitum (dpc). No hybridization signal was demonstrated beyond th...
Distinction between metabolic and myogenic mechanisms of coronary hyperemic response to brief diastolic occlusion.
Authors: G PDubé, K GBemis, J CGreenfield
Journal: Circulation Research (1991)

We monitored an index of coronary vascular resistance (mean aortic pressure/mean coronary flow) in 19 heart-blocked conscious dogs paced at 60 beats/min and instrumented with an aortic pressure catheter, left circumflex artery electromagnetic flow probe, and a coronary occluder. Cessation of pacing for a single beat resulted in a long diastole control (LDC) intervention beat of 2-second duration characterized by a progressive rise in diastolic coronary vascular resistance index. A 400-msec coronary artery occlusion early in a long diastole (LD4) dramatically inhibited the rate of rise in resistance index during the first 600 msec (phase 1) after occlusion. Partial recovery of the resistance index rise rate was evident during the remaining 400 msec (phase 2) of the long diastole. In nine dogs, LDC and LD4 intervention beats were instituted during two conditions of myocardial metabolic activity in which the myogenic stimuli associated with coronary occlusion would be similar: 1) paired pacing and 2) normal ...
Doxorubicin toxicity in perfused rat heart. Decreased cell death at low oxygen tension.
Authors: P EGaney, L SCarter, R AMueller, R GThurman
Journal: Circulation Research (1991)

The purpose of these studies was to test whether O2 tension influences cardiotoxicity due to doxorubicin. Isolated hearts were perfused by the method of Langendorff at constant pressure with Krebs-Henseleit buffer saturated with 5% CO2 and either 95% or 20% O2. Toxicity due to doxorubicin was evaluated from changes in heart rate and from uptake of trypan blue by nonviable nuclei. Heart rate was stable in control hearts perfused at 95% O2 for 30 minutes but decreased in hearts perfused at 20% O2. Doxorubicin (30 microM) increased O2 uptake due to redox cycling by approximately 75 mumol/g/hr at 95% O2 but had no effect in hearts perfused at 20% O2. Heart rate decreased during 30 minutes of perfusion with doxorubicin and 95% or 20% O2, with greater decreases occurring with 95% than 20% O2 compared with values for the respective untreated controls. Irreversible cell damage indexed from uptake of vital dye due to doxorubicin was threefold greater than control at 95% O2 but was not different from control at at ...
Cardiac Surgery in the Adult
Authors: Fred A. Crawford
Journal: JAMA (2008)

Our website uses cookies to enhance your experience. By continuing to use our site, or clicking "Continue," you are agreeing to our Cookie Policy | Continue JAMA HomeNew OnlineCurrent IssueFor Authors Publications JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry (1919-1959) Podcasts Clinical Reviews Editors' Summary Medical News Author Interviews More JN Learning / CMESubscribeJobsInstitutions / LibrariansReprints & Permissions Terms of Use | Privacy Policy | Accessibility Statement 2023 American Medical Association. All Rights Reserved Search All JAMA JAMA Network Open JAMA Cardiology JAMA Dermatology JAMA Forum Archive JAMA Health Forum JAMA Internal Medicine JAMA Neurology JAMA Oncology JAMA Ophthalmology JAMA Otolaryngology–Head & Neck Surgery JAMA Pediatrics JAMA Psychiatry JAMA Surgery Archives of Neurology & Psychiatry Input Search Term Sign In Individual Sign In Sign inCreate an Account Access through your institution Sign In Purchase Options: Buy this article Rent this article Subscribe to the JAMA journal
Postextrasystolic potentiation. Do we really know what it means and how to use it
Authors: M WCooper
Journal: Circulation (1993)

Postextrasystolic potentiation (PESP), the increase in contractility that follows an extrasystole, is an interesting phenomenon that has been known for almost 100 years. The literature on this effect is reviewed. It is found that there is significant evidence that the phenomenon is independent of muscle loading and represents a distinct property of the myocardium. Examination of the literature pertaining to the cause of the effect suggests that calcium shifts within the sarcoplasmic reticulum are responsible, although there are some conflicts with this conclusion. Regarding the utility of PESP as a diagnostic test of latent viability of ischemic myocardium, the literature review reveals contradictions and conflicts with several methodological problems of the experiments. Finally, concerning the utility of continuous PESP (paired-pacing) to augment ventricular function in the failing ventricle, the studies again are inconclusive and methodologically suspect. Conditions for the proper analysis of the PESP r...
Effect of reperfusion late in the phase of reversible ischemic injury. Changes in cell volume, electrolytes, metabolites, and ultrastructure.
Authors: R BJennings, JSchaper, M LHill, CSteenbergen, K AReimer
Journal: Circulation Research (1985)

The acute effects of reperfusion on myocardium reversibly damaged by 15 minutes of severe ischemia in vivo, were studied. Changes in the adenine nucleotide pool, cell volume regulation, myocardial calcium, and ultrastructure were studied at the end of 15 minutes of ischemia and after 0.5, 3.0, and 20 minutes of reflow. Before reperfusion, adenosine triphosphate and the adenylate pool decreased by 63% and 44% of control, respectively, and the adenylate charge was reduced to 0.65. After 3 minutes of reperfusion, the adenylate charge was restored to control by the rephosphorylation of adenosine mono- and diphosphate, but adenosine triphosphate was still reduced by 45%. Mild tissue edema was detected after 0.5 minute of reflow and persisted throughout 20 minutes of reperfusion. The increased tissue water was accompanied by a slight increase in sodium and a marked increase in tissue potassium. Although massive calcium accumulation develops when irreversibly injured tissue is reperfused, no calcium overload was...
Three-dimensional echocardiographic reconstruction of the mitral valve, with implications for the diagnosis of mitral valve prolapse.
Authors: R ALevine, M DHandschumacher, A JSanfilippo, A AHagege, PHarrigan, J EMarshall, A EWeyman
Journal: Circulation (1989)

Mitral valve prolapse has been diagnosed by two-dimensional echocardiographic criteria with surprising frequency in the general population, even when preselected normal subjects are examined. In most of these individuals, however, prolapse appears in the apical four-chamber view and is absent in roughly orthogonal long-axis views. Previous studies of in vitro models with nonplanar rings have shown that systolic mitral annular nonplanarity can potentially produce this discrepancy. However, to prove directly that apparent leaflet displacement in a two-dimensional view does not constitute true displacement above the three-dimensional annulus requires reconstruction of the entire mitral valve, including leaflets and annulus. Such reconstruction would also be necessary to explore the complex geometry of the valve and to derive volumetric measures of superior leaflet displacement. A technique was therefore developed and validated in vitro for three-dimensional reconstruction of the entire mitral valve. In this ...
Contribution of skeletal muscle atrophy to exercise intolerance and altered muscle metabolism in heart failure.
Authors: D MMancini, GWalter, NReichek, RLenkinski, K KMcCully, J LMullen, J RWilson
Journal: Circulation (1992)

BACKGROUNDThe purpose of this study was to investigate the prevalence of skeletal muscle atrophy and its relation to exercise intolerance and abnormal muscle metabolism in patients with heart failure (HF).METHODS AND RESULTSPeak VO2, percent ideal body weight (% IBW), 24-hour urine creatinine (Cr), and anthropometrics were measured in 62 ambulatory patients with HF. 31P magnetic resonance spectroscopy (MRS) and imaging (MRI) of the calf were performed in 15 patients with HF and 10 control subjects. Inorganic phosphorus (Pi), phosphocreatine (PCr), and intracellular pH were measured at rest and during exercise. Calf muscle volume was determined from the sum of the integrated area of muscle in 1-cm-thick contiguous axial images from the patella to the calcaneus. A reduced skeletal muscle mass was noted in 68% of patients, as evidenced by a decrease in Cr-to-height ratio of less than 7.4 mg/cm and/or upper arm circumference of less than 5% of normal. Calf muscle volume (MRI) was also reduced in the patients ...
Adjuvant Trastuzumab in HER2-Positive Breast Cancer
Authors: Joke Vanderhaegen, Robert Paridaens, Patrick Neven
Journal: New England Journal of Medicine (2012)

To the Editor: In their article regarding the Breast Cancer International Research Group 006 (BCIRG-006) trial (ClinicalTrials.gov number, NCT00021255), Slamon et al. (Oct. 6 issue)1 find that a regimen omitting an anthracycline (docetaxel, carboplatin, and trastuzumab [TCH]) was superior to doxorubicin and cyclophosphamide followed by docetaxel (AC-T) in the adjuvant treatment of human epidermal growth factor receptor 2 (HER2)–positive breast cancer. Although TCH is attractive because it rarely causes cardiac dysfunction, it is not clear in whom this regimen should be used rather than another standard regimen with AC-T plus trastuzumab. Coamplification of the gene encoding topoisomerase II alpha (TOP2A) and HER2 is a candidate-predictive factor for anthracycline sensitivity; however, this study did not show the expected result. Interestingly, among patients with TOP2A coamplification, the superiority of trastuzumabcontaining regimens was not significant. This finding may mean that HER2 function is different between the groups with and without TOP2A coamplification. We would be grateful if the authors would provide us with information on the correlation between the TOP2A copy number and the HER2 copy number. Daisuke Kaji, M.D. Yuji Miura, M.D. Toshimi Takano, M.D.
Comparison Of Short And Medium Term Relief Of Gastric Outlet Obstruction Symptoms Via Enteral Stents Or Eus-Guided Gastroenterostomy
Authors: V Dhir, P Udawat, R Shah
Journal: Endoscopy (2021)

Aims To compare the quality of relief of obstructive symptoms following enteral stent placement or EUS-GJ by utilizing the Gastric outlet obstruction scoring system (GOOSS, Adler 2002). A secondary aim was to assess the need for re-intervention after the index procedure.
Description of Endoscopic Surveillance Adherence of Colorectal Cancer Patients Following Surgery
Authors: L Vásquez-Sánchez, MA Herrera-Servin, CJ Mata-Quintero
Journal: Endoscopy (2021)

Aims The aim of surveillance is improvement of patient survival by early detection of recurrence or metachronous cancer. The objetive is to know the endoscopic surveillance adherence in patients undergoing surgery with curative intent for colorectal cancer at a Mexican hospital. Analize the prevalence and recurrence with the endoscopic protocol described in the literature.