tbuckley/cabot-search huggingface dataset:
Trans-sarcolemmal Ca2+ movements associated with contraction of the rabbit right ventricular wall.
Authors: G NPierce, T LRich, G ALanger
Journal: Circulation Research (1987)

The purpose of this study was to examine the movements of Ca2+ into the myocardium from the extracellular space during the course of muscle contraction. Equilibration of the rabbit right ventricular wall with perfusate containing 45Ca was measured by collecting effluent droplets over time. This protocol was carried out in a quiescent muscle and then repeated 15-20 minutes later in an identical fashion except that halfway through the collection period the muscle was stimulated to contract. We were thus able to quantitate the contraction-dependent changes in 45Ca movements. In control experiments using [58Co]EDTA as an extracellular space marker, we observed that contraction altered the volume of this space. This alteration in extracellular space was relatively small, and the quantitation of 45Ca movements was corrected for this change. The addition of 1 microM Bay K 8644 to the perfusate stimulated tension and augmented Ca2+ depletion from the extracellular space. The addition of 15 microM nifedipine to th...
<i>In Vivo</i> Effects of LSD1 Inhibition By Small Chemical Inhibitors in Sickle Cell Mice
Authors: Cuong Le, Greggory Myers, Alawi Habara, Natee Jearawiriyapaisarn, Mary Lee, David H.K. Chui, Martin H. Steinberg, James Engel, Shuaiying Cui
Journal: Blood (2017)
Silent ischemia during daily life is an independent predictor of mortality in stable angina.
Authors: P CDeedwania, E VCarbajal
Journal: Circulation (1990)

We prospectively examined the prognostic significance of silent myocardial ischemia detected by ambulatory electrocardiogram (ECG) monitoring during daily life in 107 patients with long-term stable angina who were symptomatically controlled on conventional antianginal agents. Forty-six patients (group 1) demonstrated one or more episodes (87% silent) of myocardial ischemia; the remaining 61 patients (group 2) had no ischemic ST segment changes. During the mean follow-up period of 23 +/- 8 months, 11 cardiac deaths (five sudden and six nonsudden) occurred in group 1, and five cardiac deaths (all nonsudden) occurred in group 2. Kaplan-Meier survival analysis between the groups confirmed that patients with silent ischemia (group 1) had worse prognoses during the follow-up period (p = 0.023). Although the higher incidence of hypertension, smoking, hypercholesterolemia, and diabetes in our patients might reflect a more sickly population of stable angina patients, the multivariate Cox's hazard function analysis...
Cardiovascular and renal hemodynamic effects of intravenous infusions of the selective DA1 agonist, fenoldopam, used alone or in combination with dopamine and dobutamine.
Authors: N ALass, DGlock, L IGoldberg
Journal: Circulation (1988)

Fenoldopam (0.1 and 0.2 microgram/kg/min i.v.) was administered to pentobarbital-anesthetized dogs alone and combined with dopamine (DA) and dobutamine. Renal blood flow, heart rate, and mean arterial pressure were measured. Both dosages of fenoldopam increased renal blood flow without altering blood pressure, similar to the effects of DA (1 and 2 micrograms/kg/min). Administration of fenoldopam with only DA (1 microgram/kg/min) produced further increase in renal blood flow. After administration of phenoxybenzamine (15 mg/kg i.v.), DA produced significant increments in renal blood flow and reductions in renal vascular resistance when compared with experiments without phenoxybenzamine, suggesting even low dosages of DA exert alpha-adrenoceptor agonist activity. Dobutamine (2 and 4 micrograms/kg/min) increased renal blood flow about 37% of that produced by DA. Fenoldopam added to dobutamine produced similar increments in renal blood flow as DA. Fenoldopam did not affect the increase in cardiac contractile f...
ATP directly affects junctional conductance between paired ventricular myocytes isolated from guinea pig heart.
Authors: HSugiura, JToyama, NTsuboi, KKamiya, IKodama
Journal: Circulation Research (1990)

Effects of ATP on junctional conductance (gj) were investigated in paired ventricular myocytes isolated from guinea pig hearts. One cell of the pair was voltage-clamped with a single-patch pipette, and gj was measured after the perforation of the nonjunctional membrane of the partner cell. The current-voltage relation of gj was linear between -30 and +30 mV. The control gj at 5.0 mM ATP in 88 pairs of cells ranged from 100 to 1,055 nS (average, 268 nS). ATP within the range from 0.1 to 5.0 mM increased gj in a dose-dependent manner. The Hill coefficient was 2.6, and the half-maximum effective concentration of ATP was 0.68 mM. Adenylylimidodiphosphate (2 mM) caused a transient increase in gj in the presence of 0.5 mM ATP, but forskolin (30 microM), cyclic AMP (50 microM), catalytic subunit of cyclic AMP-dependent protein kinase (1 microM), and ADP (10 mM) had no significant effect on gj. The temperature coefficient of gj in the presence of 5.0 mM ATP was 1.29. These findings suggest that gj in paired ventr...
Rapid recovery of cardiac beta-adrenergic receptors after isoproterenol-induced "down"-regulation.
Authors: C JLimas, CLimas
Journal: Circulation Research (1984)

Desensitization of beta-receptor-linked adenylate cyclase occurs after prolonged occupancy of the beta-receptors by their agonists. We have followed the development and recovery from down-regulation of beta-receptors in enzymatically dissociated cardiac myocytes by using the hydrophilic antagonist [3H]-CGP-12177 to identify surface-bound beta-receptors. After in vitro incubation with (-)-isoproterenol, almost 50% of the beta-receptors are lost within 10 minutes. Isoproterenol-mediated cyclic adenosine monophosphate accumulation by isolated myocytes was also decreased after a 15-minute preincubation with isoproterenol. Lost beta-receptors can, however, be recovered when isoproterenol-pretreated, washed cardiac myocytes are incubated at 37 degrees C, 85 +/- 7% of the lost beta-receptors have returned to the cell surface after 20 minutes of incubation. The requirements for such recycling were investigated. Receptor recovery does not depend on de novo protein synthesis, since it is unaffected by prior exp...
Abstract 14760: Myocardial Scarring by Magnetic Resonance Predicts Sudden Cardiac Death in Pediatric Patients With Hypertrophic Cardiomyopathy
Authors: Lars Grosse-Wortmann, Laurine van der Wal, Aswathy Vaikom House, Lee Benson, Raymond Chan
Journal: Circulation (2020)

Introduction: Cardiovascular magnetic resonance (CMR) with late gadolinium enhancement (LGE) has been shown to be an independent predictor of sudden cardiac death (SCD) in adults with hypertrophic cardiomyopathy (HCM). The clinical significance of LGE in pediatric HCM patients is unknown. Hypothesis: LGE improves the SCD risk prediction in children with HCM. Methods: We retrospectively analyzed the CMR images and reviewed the outcomes pediatric HCM patients. Results: Amongst the 720 patients from 30 centers, 73% were male, with a mean age of 14.2±4.8 years. During a mean follow up of 2.6±2.7 years (range 0-14.8 years), 34 experienced an episode of SCD or equivalent. LGE (Figure 1A) was present in 34%, with a mean burden of 14±21g, or 2.5±8.2g/m2 (6.2±7.7% of LV myocardium). The presence of ≥1 adult traditional risk factor (family history of SCD, syncope, LV thickness &gt;30mm, non-sustained ventricular tachycardia on Holter) was associated with an increased risk of SCD (HR=4.6, p&lt;0.0001). The HCM Risk-Kids score predicted SCD (p=0.002). The presence of LGE was strongly associated with an increased risk (HR=3.8, p=0.0003), even after adjusting for traditional risk factors (HR adj =3.2, p=0.003) or the HCM Risk-Kids score (HR adj =3.5, p=0.003). Furthermore, the burden of LGE was associated with increased risk (HR=2.1/10% LGE, p&lt;0.0001). LGE burden remained independently associated with an increased risk for SCD after adjusting for traditional risk factors (HRadj=1.5/10% LGE, p=0.04) or HCM Risk-Kids (HRadj=1.9/10% LGE, p=0.0018, Figure 1B). The addition of LGE burden improved the predictive model using traditional risk markers (C statistic 0.67 vs 0.77, p=0.003) and HCM Risk-Kids (C statistic 0.68 vs 0.74, p=0.045). Conclusions: Quantitative LGE is an independent risk factor for SCD in pediatric patients with HCM and improves the performance of traditional risk markers and the HCM Risk-Kids Score for SCD risk stratification in this population.
Effects of acebutolol on myocardial infarct extension: a randomized electrocardiographic, enzymatic and angiographic study.
Authors: IAzancot, PLorente, GGeorgiopoulos, PBeaufils, CMasquet, YBaudouy, RSlama
Journal: Circulation (1982)

The effect of acebutolol (1 mg/kg i.v. during the first 2 days followed by a daily oral dose of 600 mg for 3 weeks) was studied in a randomized trial involving 26 patients seen within 24 hours after the onset of uncomplicated anterior transmural myocardial infarction (TMI). Myocardial ischemia and necrosis were evaluated by precordial maps recorded daily for 9 days. Left ventricular pump function and dyssynergy were quantitatively measured on 30 degrees right anterior oblique cineangiograms. Angiography was performed, using the postextrasystolic potentiation technique, within the first 24 hours after TMI and was repeated 1 month later. The basal and postextrasystolic beats from the initial angiography were computerized and compared with those from the final angiogram. MB-CK serum level was measured from blood samples drawn every 3 hours for the first 72 hours. Fourteen patients selected at random received acebutolol within the first 24 hours; 12 subjects were untreated and served as controls. During the 1...
RESPONSE: Re: Association Between Biallelic and Monoallelic Germline MYH Gene Mutations and Colorectal Cancer Risk
Authors: S. P. Cleary, M. E. Croitoru, R. Gryfe, M. Manno, M. Cotterchio, J. Knight, S. Gallinger
Journal: JNCI Journal of the National Cancer Institute (2005)

We read with interest the paper by Croitoru et al. ( 1 ) , in which they examined the role of germline MYH gene mutations in colorectal cancer and proposed an autosomal dominant weakly penetrant mode of inheritance.Previous evidence has suggested a recessive mode of inheritance for colorectal polyposis ( 2 ) .Hence, the novel proposal by Croitoru et al. would be of major clinical and scientifi c importance and must be fully justifi ed by the data.We have major concerns about their fi ndings and respectfully refute their interpretation of their data.The authors compared case patients and control subjects with no MYH gene mutations (genotype Wt/Wt) with case patients and control subjects with either one (genotype Wt/Mut) or two (genotype Mut/Mut) MYH gene mutations.However, the authors' data do not support a * MYH = MutY human homologue gene; Wt = wild type; Mut = mutant.
Endoscopic Submucosal Dissection using Detachable Assistant Robot: Comparative in Vivo Feasibility Study
Authors: SH Kim, HS Choi, KW Lee, HJ Jeon, JM Lee, ES Kim, B Keum, YT Jeen, HS Lee, HJ Chun
Journal: Endoscopy (2021)

Aims Appropriate tissue tension and clear visibility of the dissection area by traction are essential for effective and safe endoscopic submucosal dissection (ESD). We developed a robotic assistive traction device for flexible endoscopy, and compared its safety and efficiency in ESD between experienced and novice endoscopists.
Long-term safety of infants from mothers with chronic hepatitis B treated with tenofovir disoproxil in China
Authors: Calvin Q. Pan, Erhei Dai, Zhongping Duan, Guorong Han, Wenjing Zhao, Yuming Wang, Huaihong Zhang, Baoshen Zhu, Hongxiu Jiang, Shuqin Zhang, Xiaohu Zhang, Huaibin Zou, Xiuli Chen, Yu Chen
Journal: Gut (2021)

Objective The physical and neuromental development of infants remains uncertain after fetal exposure to tenofovir disoproxil fumarate (TDF) for the prevention of mother-to-child transmission of HBV. We aimed to investigate the safety of TDF therapy during the third trimester of pregnancy. Design Infants from a previous randomised controlled trial were recruited for our long-term follow-up (LTFU) study. Mothers with chronic hepatitis B were randomised to receive TDF therapy or no treatment during the third trimester. Infants’ physical growth or malformation, bone mineral density (BMD) and neurodevelopment, as assessed using Bayley-III assessment, were examined at 192 weeks of age. Results Of 180 eligible infants, 176/180 (98%) were enrolled and 145/176 (82%) completed the LTFU (control group: 75; TDF-treated group: 70). In the TDF-treated group, the mean duration of fetal exposure to TDF was 8.57±0.53 weeks. Congenital malformation rates were similar between the two groups at week 192. The mean body weight of boys in the control and TDF-treated groups was significantly higher (19.84±3.46 kg vs. 18.47±2.34 kg; p=0.03) and within the normal range (18.48±2.35 kg vs. 17.80±2.50 kg; p=0.07), respectively, when compared with the national standard. Other prespecified outcomes (head circumference, height, BMD, and cognitive, motor, social–emotional, and adaptive behaviour measurements) were all comparable between the groups. Conclusion Infants with fetal exposure to TDF had normal physical growth, BMD and neurodevelopment at week 192. Our findings provide evidence on the long-term safety of infants after fetal exposure to maternal TDF therapy for preventing hepatitis B transmission. Trial registration number NCT01488526 .
Evaluation of left ventricular size and function by echocardiography. Results in normal children.
Authors: H PGutgesell, MPaquet, D FDuff, D GMcNamara
Journal: Circulation (1977)

Left ventricular (LV) size and function were studied by echocardiography in 145 normal children. The LV end-diastolic diameter (EDD) and its percentage change with systole (%deltaLVD) were measured and mean velocity of circumferential fiber shortening (Vcf) calculated. The LV pre-ejection period (PEP) and ejection time (LVET) were determined from recordings of aortic valve motion. The EDD increased by approximately threefold during childhood and was best correlated with the log of body weight (r = 0.95) and the log of body surface area (r = 0.96). The mean %deltaLVD was 36 +/- 4 (SD), and this index of LV function was independent of age and heart rate. Mean Vef was higher, and the absolute values of PEP and LVET shorter, in younger children with a faster heart rate. The mean ratio of PEP/LVET was 0.31 +/- 0.003, and was relatively independent of age (r = 0.41) and heart rate (r = 0.37). The %deltaLVD and PEP/LVET appear to be particularly useful indices of LV function because they remain constant during t...
Protective effects of long-term bradycardial pacing against catecholamine-induced myocardial damage in rabbit hearts.
Authors: M DBrown, OHudlická
Journal: Circulation Research (1988)

A high intravenous dose of norepinephrine (4 micrograms/kg/min for 60 minutes) to New Zealand Red rabbits produced patchy subendocardial damage (estimated stereologically in frozen sections) of about 5% of the heart volume 2 days after application. The damaged areas showed loss of staining for alkaline phosphatase, an enzyme present in normal capillary endothelium. Heart performance (cardiac output index, cardiac work [i.e., cardiac output X mean blood pressure], and dP/dtmax) were significantly lower than in control hearts. Capillary density distribution estimated in nondamaged areas of the left ventricular free wall was inhomogeneous favoring subepicardial regions, while homogeneous transmural distribution was found in control hearts. Bradycardial pacing (reduction of heart rate to 50% of normal) performed for 3-4 weeks prior to norepinephrine administration showed a protective effect against catecholamine damage manifested in a smaller extent of necrosis, in the maintenance of homogeneous transmural ca...
The relationship of vascular injury and myocardial hemorrhage to necrosis after reperfusion.
Authors: M CFishbein, JY-Rit, ULando, KKanmatsuse, J CMercier, WGanz
Journal: Circulation (1980)

Early reperfusion may salvage ischemic myocardium; late reperfusion often intensifies morphologic changes of necrosis and causes hemorrhage. To determine whether hemorrhage after reperfusion increases the extent of myocardial infarction, six closed-chest, anesthetized dogs underwent balloon occlusion of the left anterior descending coronary artery for 5.5 hours, followed by 30 minutes of reflow. Colloidal carbon was injected distal to the balloon before reperfusion to label injured vessels. After sacrifice, the area of myocardial necrosis was measured by planimetry of 1-cm-thick serial slices of left ventricle stained with triphenyl tetrazolium chloride. Areas of hemorrhage and vascular injury were also measured. In all hearts, the extent of hemorrhage and vascular injury was less than the extent of necrosis (10.2 +/- 4.6% vs 19.8 +/- 8.6% [mean +/- SD], p < 0.01). Further, hemorrhage was always within the area of necrosis, primarily in the subendocardial portion. Hemorrhage after reperfusion occurred onl...
Occupational risk of human parvovirus B19 infection for school and day-care personnel during an outbreak of erythema infectiosum
Authors: S. M. Gillespie
Journal: JAMA (1990)

Human parvovirus B19, the cause of erythema infectiosum, has recently been associated with adverse fetal outcomes. During a large outbreak of erythema infectiosum in Connecticut, a survey was conducted on 571 (90%) of 634 school and day-care personnel to determine the risk of acquiring B19 infection. Serologic evidence of B19 infection was determined by using an enzyme-linked immunosorbent assay. Of the school and day-care personnel, 58% had evidence of previous B19 infection. The minimal rate of B19 infection in susceptible personnel during the outbreak was 19%. The risk was increased for teachers and daycare providers who had contact with younger children and with greater numbers of ill children. These results suggest that B19 infection is an occupational risk for school and day-care personnel. (<i>JAMA</i>. 1990;263:2061-2065)
Intracellular calcium and ventricular fibrillation. Studies in the aequorin-loaded isovolumic ferret heart.
Authors: YKihara, J PMorgan
Journal: Circulation Research (1991)

To elucidate the role of changes in [Ca2+]i in the induction of ventricular fibrillation (VF), Ca2+i signals, epicardial electrical potentials, and isovolumic left ventricular pressure were simultaneously recorded in isolated intact ferret hearts loaded with aequorin, a bioluminescent protein. When the preparations were perfused with 3 microM acetylstrophanthidin and 8 mM Ca2+, or with a low Na+ solution (18 mM Na+, 100 mM Li+), spontaneous transitions to the VF state were consistently observed within a short period of time. The initiation of spontaneous VF was preceded by development of a Ca2+i overload state, coincidental with the ascending phase of diastolic Ca2+i oscillations, and was followed by further elevation in Ca2+i levels, which were associated with augmented Ca2+i oscillations of a saw-toothed pattern. Pretreatment with 10 microM ryanodine, which blocked Ca2+i oscillations in the preparation, did not eliminate inducibility of VF by means of AC electrical stimulations; however, VF no longer oc...
Design And Validation Of A Live Animal Model For Therapeutic Endoscopic Ultrasound (EUS) Training Program. Taking Training To A Next Level
Authors: L Sosa Valencia, J Huppertz, F Wanert, F Haberzetser, L Swanström
Journal: Endoscopy (2021)

Aims EUS used for tumor staging has evolved into a therapeutic modality, transforming surgical procedures into minimally endoscopic treatments. Mentoring, live demonstrations, simulators, ex-vivo models/phantoms are the current teaching methods for therapeutic EUS (TEUS). Need’s to improve this training has been proposed.
Impaired potassium-induced dilation in hypertensive rat cerebral arteries does not reflect altered Na+,K(+)-ATPase dilation.
Authors: J GMcCarron, WHalpern
Journal: Circulation Research (1990)

We have recently demonstrated that K(+)-induced dilation of cerebral resistance-sized vessels has two independent components, only one of which seemed sodium pump dependent. In our current investigation, potassium-induced dilation of spontaneous tone was compared in cerebral arteries from normotensive Wistar-Kyoto rats and age-matched stroke-prone spontaneously hypertensive rats. Branches of the posterior cerebral artery were cannulated and pressurized, and these vessels developed spontaneous tone. After a 5-minute period in K(+)-free physiological saline solution, K+ was increased in 1-mM increments to a final concentration of 15 mM. In the normotensive arteries, K+ concentrations between 0 and 5 mM K+ resulted in dilations that had a transient (sodium pump-dependent) component, and K+ concentrations in excess of 7 mM produced dilations that lacked a transient (sodium pump-independent) component. Similar branches from the hypertensive rat also responded with transient dilations to K+ (less than 5 mM), an...
Stigmatizing Language About Neonatal Abstinence Syndrome
Authors: Alicia Kowalchuk, Maria Mejia de Grubb, Roger Zoorob
Journal: JAMA (2018)

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Determinants of a protective effect of glucose and insulin on the ischemic myocardium. Effects on contractile function, diastolic compliance, metabolism, and ultrastructure during ischemia and reperfusion.
Authors: C SApstein, F NGravino, C CHaudenschild
Journal: Circulation Research (1983)

The efficacy of hyperglycemia and insulin therapy for reducing ischemic myocardial injury is controversial and unproven. Accordingly, factors that might influence the effects of hyperglycemia and insulin were studied in isolated perfused rabbit hearts at two degrees of global ischemia, either severe or moderate. During the ischemic period, different groups (n = 15-28/group) received either 100 mg/100 ml glucose-no insulin (control group), 500 mg/100 ml glucose + 100 mU/ml insulin (G + I), or 100 mg/100 ml glucose + 400 mg/100 ml mannitol (osmotic control). During moderate ischemia, effective washout of myocardial lactate was maintained, and hyperglycemia and insulin doubled the glycolytic flux, completely prevented contracture during ischemia, decreased contracture during reperfusion, increased recovery of postischemic contractile function, decreased ultrastructural damage, and increased high energy phosphate levels. Hyperglycemia and insulin increased glycolytic flux only after 30 minutes of ischemia...