tbuckley/cabot-search huggingface dataset:
Shall The Journal be Removed to Washington?
Authors: L. M. Gates
Journal: JAMA (1891)

<h3>To the Editor:</h3> —I protest against using any more of the space ofThe Journaldiscussing its removal, and with S. E. Hampton, M.D., of Kentucky, move the previous question. Am willing that it should remain at Chicago, only make a good Journal of it. Am happy to note improvement. Scranton, Pa., March 23, 1891.
Improvement in exercise capacity and exercise hemodynamics 3 months after double-balloon, catheter balloon valvuloplasty treatment of patients with symptomatic mitral stenosis.
Authors: C RMcKay, D TKawanishi, AKotlewski, KParise, TOdom-Maryon, AGonzalez, C LReid, S HRahimtoola
Journal: Circulation (1988)

Clinical status, exercise treadmill performance, and hemodynamics were determined in 24 patients with symptomatic mitral stenosis before catheter balloon valvuloplasty (CBV) and at 3 months follow-up. Hemodynamic determinations at rest showed that mitral CBV performed by the double-balloon technique resulted in significant immediate decreases in mean pulmonary arterial wedge pressure (28 +/- 7 to 16 +/- 5 mm Hg, p less than .01), mean pulmonary arterial pressure (41 +/- 11 to 33 +/- 10 mm Hg, p less than .05), and mitral valve gradient (16 +/- 7 to 6 +/- 3 mm Hg, p less than .01), and significant increases in cardiac output (4.3 +/- 1.1 to 5.0 +/- 1.4 liters/min, p less than .01). Mitral valve area increased from 1.0 +/- 0.3 to 2.2 +/- 0.7 cm2 (p less than .01). The mitral valve area was unchanged (2.0 +/- 0.7 cm2, p = NS) at 3 months. The lower pulmonary arterial wedge pressure, pulmonary arterial pressure, and mitral valve gradient persisted at 3 month follow-up catheterization. Clinical examinations sh...
Accurate volume determination in the isolated ejecting canine left ventricle by two-dimensional echocardiography.
Authors: L WEaton, W LMaughan, A AShoukas, J LWeiss
Journal: Circulation (1979)

Two-dimensional echocardiography can provide serial cross-sectional images of the left ventricular cavity. We examined whether such serial images from steady-state ejecting hearts would allow three-dimensional reconstruction and accurate volume estimation without major geometric assumptions. Cross-circulated, paced dog hearts were suspended in a blood-filled tank. Serial cross-sectional images were taken at 3-mm intervals along the vertical axis. Left ventricular cavity and muscle areas of each image were planimetered with a light-pen system and summated for volume: total volume = sigma (areas x 3 mm). Direct left ventricular volume was measured through the cardiac cycle with a volumetric chamber connected to a balloon in the ejecting left ventricle. In six hearts, 67 separate direct volume measurements (range 9.5--54.7 ml) from various points in the cardiac cycle were compared with the simultaneous echo volume measurements. By least squares linear regression, echo volume = 1.01 (direct volume) - 0.44 ml;...
Intracellular calcium storage and release in the human platelet. Chlorotetracycline as a continuous monitor.
Authors: WJy, D HHaynes
Journal: Circulation Research (1984)

The calcium-sensitive fluorescent probe chlorotetracycline was used to monitor calcium movement in human platelets. The chlorotetracycline fluorescence signal is a linear measure of the level of free calcium in the dense tubules and in the mitochondria, with probe sensitivity in the millimolar range. Experiments perturbing the system with the calcium ionophore A23187 shows that the level of free internal calcium in the organelle depends upon the cytoplasmic level, which, in turn, depends upon the passive permeability of the plasma membrane. Chlorotetracycline in the cytoplasmic compartment does not respond to changes in the cytoplasmic calcium concentration, which is held in the micromolar to submicromolar range by an extrusion system. The calcium concentration in the cytoplasmic compartment can be directly manipulated by the calcium ionophore A23187 and is measured in parallel experiments with Quin 2, a high-affinity indicator. The calcium transport systems of the organelles are shown to be less suscepti...
Whole-cell and single-channel calcium currents of isolated smooth muscle cells from saphenous vein.
Authors: AYatani, C LSeidel, JAllen, A MBrown
Journal: Circulation Research (1987)

Whole-cell and single-channel calcium currents in enzymatically isolated dog saphenous vein cells were recorded by the patch-clamp method. Test pulses to negative potentials from holding potentials of -90 to -40 mV elicited currents that inactivated quickly and in a voltage-dependent manner (called I low for low threshold). A second calcium current persisted even at relatively positive holding potentials of -30 to -10 mV, required stronger depolarizations for maximum current, and inactivated slowly (I high for high threshold). I high transported barium more than calcium, whereas I low transported the two ions equally. Single-channel current records (90 mM barium) showed a larger conductance that activated at relatively positive potentials and a smaller (about one-third) conductance that activated at weak depolarizations. Nitrendipine suppressed I high, and the effect was voltage dependent as observed in cardiac cells, although block of resting channels was much greater in vein cells (KR approximately 10(-...
Triamterene inhibits the delayed rectifier potassium current (IK) in guinea pig ventricular myocytes.
Authors: PDaleau, JTurgeon
Journal: Circulation Research (1994)

In humans, proarrhythmia during therapy with action potential-prolonging drugs can be associated with hypokalemia often provoked by concomitant administration of diuretic agents. Consequently, therapy with class III antiarrhythmics and K(+)-sparing diuretics, such as triamterene, may be indicated. Triamterene, along with its K(+)-sparing properties, exhibits other pharmacological effects. In the heart, it can increase action potential duration (guinea pig atria and papillary muscles), protect against reperfusion-induced arrhythmias (rat), and increase the QT interval (humans). Therefore, studies were undertaken to assess effects of triamterene on cardiac K+ repolarizing currents. Guinea pig ventricular myocytes were superfused at 30 degrees C with Cd(2+)-containing solution to block Isi and held at -40 mV to inactivate INa. Currents were measured in the whole-cell configuration of the patch-clamp technique. The delayed rectifier outward current (IK) was elicited by short (250-millisecond) and long (5000-m...
Anti-Reflux Mucosal Ablation (ARMA) For Refractory Gastroesophageal Reflux Disease – An Interim Analysis
Authors: R Kalapala, N Jagtap, Z Nabi, S Darisetty, H Kanakagiri, R Goud, A Karaympudi, DN Reddy
Journal: Endoscopy (2021)

Aims Proton pump inhibitor (PPI) refractory gastroesophageal reflux disease (GERD) is major clinical problem. Minimally invasive endoscopic therapies are being developed such as anti-reflux mucosal ablation. We describe safety and short term efficacy of ARMA in PPI-refractory GERD.
Abstract 16261: Predictors of Post-Transplant Improvement in Functional Capacity in Patients Debilitated Prior to Transplant Using United Network From Organ Sharing (UNOS) Database
Authors: Vivek Modi, Dhrubajyoti Bandyopadhyay, Rishi Shrivastav, Supriya Shore, Monique Tanna, Jeremy A Mazurek, Edo Birati, Arieh Fox
Journal: Circulation (2019)

Introduction: Cardiac transplant is the treatment of choice for refractory end-stage heart failure. Careful patient selection can improve post-transplant survival and functional status however, dat...
Characterization of protein kinase C isotype expression in adult rat heart. Protein kinase C-epsilon is a major isotype present, and it is activated by phorbol esters, epinephrine, and endothelin.
Authors: M ABogoyevitch, P JParker, P HSugden
Journal: Circulation Research (1993)

The pattern of protein kinase C (PKC) isotype expression in whole extracts of dispersed, freshly isolated adult rat ventricular myocytes and adult rat heart ventricle was examined by immunoblot analysis using antisera specific for PKC-alpha, -beta 1, -gamma, -delta, -epsilon, -zeta, or -eta isotypes. This analysis revealed significant levels of expression of the Ca(2+)-independent isotype PKC-epsilon, which was detected as band of 97-kd molecular mass. PKC-zeta was detected principally as a 66-kd band that probably represented a proteolytic product of the holoenzyme. PKC-eta was detected only in whole ventricle as a doublet at 75 and 81 kd and was therefore probably present in nonmyocytic cells. PKC-alpha, -beta 1, -gamma, and -delta could not be detected. Because of our inability to detect PKC-alpha, -beta 1, -gamma, and -delta in whole extracts, PKC isotypes were partially purified from whole heart by DEAE Sepharose chromatography. PKC-alpha, -beta 1, -gamma, and -delta could still not be detected in th...
Messenger RNA levels of guanine nucleotide-binding proteins are reduced in the ventricle of cardiomyopathic hamsters.
Authors: YKatoh, IKomuro, FTakaku, HYamaguchi, YYazaki
Journal: Circulation Research (1990)

The expression of guanine nucleotide-binding protein (G-protein) genes (Gs alpha, Go alpha, Gi alpha 1, Gi alpha 2, and Gi alpha 3) was examined in the ventricle of cardiomyopathic Syrian hamsters of the Bio14.6 strain (10-35 weeks old). Northern blot analysis of total cellular RNA revealed that all G-protein genes except Gi alpha 1 were expressed in the ventricle of Syrian hamsters. Gs alpha and Gi alpha 2 genes were abundantly expressed. The expression levels of the Gs alpha and Gi alpha 2 messenger RNAs in Bio14.6 ventricles were lower than the levels in ventricles of the F1B hamster strain; the abundance of Go alpha and Gi alpha 3 messenger RNAs did not change markedly. Moreover, the messenger RNA levels of Gs alpha and Gi alpha 2 decreased as the stage of cardiomyopathy progressed. Since G-proteins are linked to adenylate cyclase, these alterations of G-protein messenger RNA levels may be related to reduced contractility of cardiomyopathic heart.
116P Real-world outcomes of patients with metastatic non-small cell lung cancer receiving 2L+ atezolizumab-based treatments in Taiwan clinical practice
Authors: S-G. Wu, C-L. Chiang, C-C. Wang, J-Y. Hung, T-C. Hsia, C-Y. Su, C-F. Chen, C-H. Kuo, J-Y. Shih
Journal: Journal of Thoracic Oncology (2021)
Systolic time intervals in adolescents. Normal standards for clinical use and comparison with children and adults.
Authors: K LWanderman, ZHayek, IOvsyshcher, GLoutaty, ACantor, YGussarsky, MGueron
Journal: Circulation (1981)

Systolic time intervals were measured in 147 healthy 13-19-year-old adolescents to derive regression equations for clinical use in this age group and to determine to what extent they differ from those of children and adults. Stepwise regression analysis showed that heart rate was the only variable consistently and significantly related to electromechanical systole (QS2), left ventricular ejection time (LVET) and preejection period (PEP). None of the other variables tested (age, height, weight, body surface area, blood pressure, hemoglobin, hematocrit and serum electrolytes), when used alone, were relevant variables in relation to QS2, LVET or PEP. The PEP/LVET ratio in adolescents was essentially independent of heart rate, as in children and adults. The regression lines for QS2, LVET and PEP in adolescents fall between those for children and adults, indicating that there is a distinct tendency toward lengthening of all the systolic time intervals with age, independent of changes in heart rate. The PEP len...
Diameters of subendocardial arterioles and venules during prolonged diastole in canine left ventricles.
Authors: OHiramatsu, MGoto, TYada, AKimura, HTachibana, YOgasawara, KTsujioka, FKajiya
Journal: Circulation Research (1994)

Using a needle-probe videomicroscope with a charge-coupled device (CCD) camera, we measured the diameter of subendocardial arterioles and venules during prolonged diastole beyond the time point at which coronary blood flow reached zero. In seven open-chest heart-blocked dogs, a sheathed needle probe with a doughnut-shaped balloon was introduced from the left atrial appendage and advanced into the left ventricle through the mitral valve. The tip of the probe was placed gently on the endocardial surface. Diameters of arterioles (n = 16) and venules (n = 16) at the beginning of long diastole ranged from 40 to 126 microns and from 32 to 192 microns, respectively. After cardiac arrest, the arteriolar diameter gradually declined with aortic pressure. Arteriolar diameters at zero flow decreased by 28 +/- 9% (mean +/- SD) compared with the initial diameter (P < .01). However, none of the subendocardial arterioles collapsed at zero flow or at 12 seconds after the beginning of prolonged diastole (8 to 9 seconds aft...
Augmented responses to vasoconstrictor stimuli in hypercholesterolemic and atherosclerotic monkeys.
Authors: D DHeistad, M LArmstrong, M LMarcus, D JPiegors, A LMark
Journal: Circulation Research (1984)

We examined effects of hypercholesterolemia and atherosclerosis on vasoconstrictor responses to norepinephrine and serotonin. Responses were compared in normal, atherosclerotic, and hypercholesterolemic but non-atherosclerotic cynomolgus monkeys. The hindlimb was perfused at constant flow so that changes in perfusion pressure indicated changes in vascular resistance. We measured the pressure gradient from the iliac to the dorsal pedal artery so that responses of the large artery segment could be determined. Serotonin decreased total hindlimb resistance in normal and hypercholesterolemic monkeys, but increased total resistance in atherosclerotic monkeys. There was a greater than 10-fold increase in constrictor responses of large arteries to serotonin in atherosclerotic monkeys, compared with normal and hypercholesterolemic monkeys. In contrast, we found that vasoconstrictor responses to norepinephrine are normal in atherosclerotic monkeys and increased in hypercholesterolemic monkeys prior to development o...
Research related to underlying mechanisms in atherosclerosis.
Authors: DSteinberg
Journal: Circulation (1979)

A brief resume of advances in atherosclerosis research over the past 30 years is presented, emphasizing the multidisciplinary origins of those advances. A somewhat more detailed review of progress in the lipoprotein field is presented as an example to illustrate the pace of research related to atherosclerosis. Finally, an attempt is made to identify some of the research areas that promise to yield valuable new insights in the next 30 years.
Resting membrane potential, extracellular potassium activity, and intracellular sodium activity during acute global ischemia in isolated perfused guinea pig hearts.
Authors: A GKléber
Journal: Circulation Research (1983)

Transmembrane potentials, extracellular potassium activity, and intracellular sodium activity were determined during acute global ischemia in Langendorff perfused guinea pig ventricles by microelectrode techniques. Resting membrane potential decreased with a sigmoidal time course from -82 mV to -49.5 +/- 2.7 mV (SD, n = 6) and extracellular potassium activity increased from 4 to 5 mM to 14.7 +/- 1.3 mM (n = 8) during 15 minutes of ischemia. The estimated potassium equilibrium potential was 7 mV more negative than resting membrane potential prior to occlusion, but approached resting membrane potential during ischemia. An increase in extracellular potassium accumulation occurred when heart rate was increased abruptly from 60 to 170 beats/min. After rapid stimulation, a transient decrease of extracellular potassium activity occurred which was abolished in the presence of 10(-6) M strophanthidin. If the preparations were paced before and after aortic occlusion at a constant rate, potassium accumulation was in...
Commentary: Patient's perspective
Authors: Jane Webb, A K Siotia
Journal: BMJ (2005)

I am happy that doctors all over the world are learning from my case1 and do not mind my name on the case report or my condition being discussed. I do not want anyone to go through what I had to.

I am very independent and look after myself. My mother is very supportive and helps me a lot. I help her with cleaning, vacuuming, washing up, chopping vegetables, and a bit of cooking. I go out on my own to the corner shops to do my shopping. I even have my own purse where I keep all my money.

I did know the implications of having the surgery. I did not have any problems with the surgery because my periods were very bad and I never wanted to have a baby anyway. My mother helped me make the decision. I do not remember much of what happened after the operation. I was too poorly, and I know only what my mother told me. So many people came to visit me but I do not remember anything.

I feel bad that my thyroid was never checked before. If this had been checked I would not have had to go through all those problems. However, I am very pleased with all the attention and care I received in my local hospital. The doctors and nurses were nice to me.

I feel all right now. I come to clinic regularly and my thyroid level is checked every six months. I am more active now than I was before. I used to sleep a lot and feel tired all the time. My skin was very dry and I put on a lot of weight. Now things have improved greatly. In the end I hope that doctors all over the world have learnt something from reading my case.
Modulation of the Purkinje-ventricular muscle junctional conduction by elevated potassium and hypoxia.
Authors: R CTan, B MRamza, R WJoyner
Journal: Circulation (1989)

Action potential transmission in the canine ventricle normally occurs from the Purkinje (P) system into the ventricular muscle (VM) at specific P-VM junction sites. Transitional (T) cells are located between the Purkinje and the ventricular (V) cells at these P-VM junction sites. It has been shown that exposure to elevated [K+]0 in combination with hypoxia produces an increase in the P-VM conduction time. To examine this increase in P-VM conduction time, simultaneous measurements of the action potential upstrokes of T cells and the activation times of the local P and V cells at P-VM junctional sites were obtained from in vitro canine papillary muscles. The effects of elevated [K+]0 and hypoxia on conduction from P cells to T cells was then compared with the conduction from T cells to V cells to assess the relative contribution of each to the increase in the P-VM conduction time. We found that this intervention has approximately equal effects on the two sequential steps involved in P-VM conduction. We then...
Frequency of the first heart sound in the assessment of stiffening of mitral bioprosthetic valves.
Authors: P DStein, H NSabbah, J BLakier, D JMagilligan, DGoldstein
Journal: Circulation (1981)

The frequency spectrum of the first heart sound (S1) was measured noninvasively in 54 patients with porcine bioprosthetic valves inserted in the mitral position. Phonocardiograms were recorded on magnetic tape on line with a signal processor with which the frequency spectrum and peak frequency of S1 were determined. In 19 patients with normal natural mitral valves, the apparent peak frequency within the range of measured frequencies of S1 was 46 +/- 2 Hz (mean +/- SEM). In 11 patients with porcine bioprosthetic valves implanted in the mitral position for less than or equal to 11/2 years, the apparent peak frequency of S1 was 43 +/- 3 Hz, which was not significantly different from S1 in patients with normal mitral valves. However, in 33 patients with porcine bioprosthetic valves in place 5-7 years, the apparent peak frequency of S1 was higher, 67 +/- 2 Hz (p < 0.001). In patients in whom the porcine bioprosthetic valve was implanted 5 years or longer, the frequency spectrum of S1 showed a greater proportio...
Tachycardia and bradycardia-dependent bundle branch block alternans: clinical observations.
Authors: H CCohen, ID'Cruz, E RArbel, RLangendorf, APick
Journal: Circulation (1977)

Eleven patients with tachycardia-dependent, bradycardia-dependent, or  bundle branch block (BBB) alternans were studied. This classification is based on the following criteria: 1) When alternans is initiated by a sudden acceleration in ventricular rate, or it appears with aberration of the second beat after a pause, the alternans is tachycardia-dependent and results from a 2:1 bidirectional block in the affected bundle branch. 2) When alternans begins with the aberrant complex terminating a pause it is bradycardia-dependent; such an alternans results from alternating bundle branch cycle lengths and refractoriness, possibly produced by alternating transseptal retrograde penetration of the affected bundle branch. 3) In cases referred to as pseudobradycardia-dependent  alternans, a change from alternans to persiscardia-dependent  alternans, a change from alternans to persistent BBB occurs as the cycle lengthens; however, the disappearance of BBB with further increase of ...
Calcium and Vitamin D Supplements and Fractures in Community-Dwelling Adults
Authors: Wen-Jun Tu, Hong Wang, Qiang Liu
Journal: JAMA (2018)

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
Effects of amiloride on metabolism and contractility during reoxygenation in perfused rat hearts.
Authors: R GWeiss, E GLakatta, GGerstenblith
Journal: Circulation Research (1990)

Myocardial recovery after hypoxia may be determined not only by the extent of metabolic depression during the hypoxic period but also by changes in cation contents as well. Calcium overload during reoxygenation, mediated in part by Na-Ca exchange and supported by the rise in cell sodium during hypoxia, may be one factor. The effects of amiloride (0.1 mM), a diuretic that inhibits Na(+)-H+ and Na-Ca exchanges in cardiac sarcolemma and mitochondria preparations, were studied during hypoxia-reoxygenation in the isovolumic, isolated rat heart. During hypoxia, cell sodium, measured using potassium ethylenediamine tetraacetate cobaltate as an extracellular marker, increased in amiloride and amiloride-free hearts, but there was no increase in cell calcium (3.3 +/- 0.3 vs. 3.6 +/- 0.9 mumol/g dry wt; p = NS). Amiloride did not alter developed pressure (DP), end-diastolic pressure (EDP), pH, or integrated areas of adenosine triphosphate (ATP) and phosphocreatine (PCr) (determined by phosphorus-31-nuclear magnetic ...
<i>TP53</i>, <i>ETV6</i> and <i>RUNX1</i> Germline Variants in Patients Developing Secondary Neoplasms after Treatment for Childhood Acute Lymphoblastic Leukemia
Authors: Stefanie V. Junk, Norman Klein, Sabine Schreek, Martin Zimmermann, Anja Möricke, Kirsten Bleckmann, Gunnar Cario, Martin Schrappe, Christian P. Kratz, Martin Stanulla
Journal: Blood (2017)