tbuckley/cabot-search huggingface dataset:
Effect of tachycardia on regional function and transmural myocardial perfusion during graded coronary pressure reduction in conscious dogs.
Authors: J MCanty, JGiglia, DKandath
Journal: Circulation (1990)

The purpose of the present study was to examine subendocardial flow and function during graded coronary pressure reduction to determine the effect of tachycardia on the lower autoregulatory pressure limit (critical coronary pressure) in unanesthetized dogs. During atrial pacing at a rate of 200 beats/min, subendocardial flow measured by radioactive microspheres averaged 1.55 +/- 0.34 ml/min/g and remained unchanged as pressure was reduced over the autoregulatory plateau from 84 +/- 10 to 59 +/- 7 mm Hg. Further reductions in coronary pressure to below a critical coronary pressure of approximately 60 mm Hg were associated with concomitant reductions in subendocardial flow and the endocardial-epicardial flow ratio during tachycardia. Although regional function remained constant over the autoregulatory plateau, there was a rightward shift of the coronary pressure-function relation during ischemia in response to a steady-state increase in rate from 100 to 200 beats/min. Reductions in regional wall thickening ...
Haemodialysis and transplantation in Wegener's granulomatosis.
Authors: C van Ypersele de Strihou, Y Pirson, J M Vandenbroucke, G P Alexandre
Journal: BMJ (1979)

Two men with Wegener9s disease began immunosuppressive treatment during severe renal insufficiency. Despite an initial temporary remission new lesions appeared and renal failure progressed. Haemodialysis was started, cytotoxic drugs were stopped, and steroid dosage was reduced. All extrarenal manifestations of the disease remitted, however, suggesting a favourable effect of either the immunosuppression induced by terminal renal failure or the haemodialysis itself. Renal transplantation was then undertaken in both patients. Thirteen and 55 months after the operations respectively renal function was satisfactory and no signs of reactivation of Wegener9s disease had appeared. These results show that whatever the activity of Wegener9s disease and its initial response to immunosuppressive agents, dialysis and transplantation are fully warranted once irreversible renal failure is established.
Passive mechanical stretch releases atrial natriuretic peptide from rat ventricular myocardium.
Authors: PKinnunen, OVuolteenaho, PUusimaa, HRuskoaho
Journal: Circulation Research (1992)

Ventricular hypertrophy is characterized by augmentation of synthesis, storage, and release of atrial natriuretic peptide (ANP) from ventricular tissue, but the physiological stimulus for ANP release from ventricles is not known. We determined the effect of graded, passive myocardial stretch on ANP release in isolated, arrested, perfused heart preparations after removal of the atria in 13-20-month-old Wistar-Kyoto (WKY) rats and spontaneously hypertensive rats (SHR). By this age, ANP gene expression was increased in the hypertrophic ventricular cells of SHR, as reflected by elevated levels of immunoreactive ANP and ANP mRNA and the increased ANP secretion (SHR, 93 +/- 14 pg/ml, n = 22; WKY rats, 22 +/- 2 pg/ml, n = 20; p less than 0.001) from perfused ventricles after removal of the atria. The release of ANP from ventricles was examined at two levels of left ventricular pressure by increasing the volume of the intraventricular balloon for 10 minutes. Stretching of the ventricles produced a rapid but trans...
Improved blood flow during prolonged cardiopulmonary resuscitation with 30% duty cycle in infant pigs.
Authors: J MDean, R CKoehler, C LSchleien, DAtchison, HGervais, IBerkowitz, R JTraystman
Journal: Circulation (1991)

BACKGROUNDSustained compression is recommended to maximize myocardial and cerebral blood flow during cardiopulmonary resuscitation (CPR) in adults and children. We compared myocardial and cerebral perfusion during CPR in three groups of 2-week-old anesthetized swine using compression rates and duty cycles (duration of compression/total cycle time) of 100 per minute, 60%; 100 per minute, 30%; and 150 per minute, 30%.METHODS AND RESULTSVentricular fibrillation was induced and CPR was begun immediately with a sternal pneumatic compressor. Epinephrine was continuously infused during CPR. Microsphere-determined blood flow and arterial and sagittal sinus blood gas measurements were made before cardiac arrest was induced and after 5, 10, 20, 35, and 50 minutes of CPR. At 5 minutes of CPR, ventricular and cerebral blood flows were greater than 25 ml.min-1 x 100 g-1 and were not significantly different between groups. When CPR was prolonged, however, myocardial and cerebral blood flows were significantly higher wi...
Recent Advances in Analytical Chemistry.
Journal: JAMA (1931)

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
Mitral A velocity wave transit time to the outflow tract as a measure of left ventricular diastolic stiffness. Hemodynamic correlations in patients with coronary artery disease.
Authors: R GPai, MSuzuki, J THeywood, D RFerry, P MShah
Journal: Circulation (1994)

BACKGROUND: Subjects in sinus rhythm have two distinct diastolic flow velocities in the left ventricular (LV) outflow tract directed toward the aortic valve. These follow E and A waves of the transmitral flow and are referred to as Er and Ar waves, respectively. The A wave transit time from the mitral valve to the LV outflow tract is shorter than that of the E wave and is shorter in those with LV hypertrophy and the aged, suggesting its possible dependence on LV late diastolic stiffness. METHODS AND RESULTS. We measured the peak-to-peak and onset-to-onset A wave transit times from the mitral valve to the LV outflow tract (AArp and AAro intervals, respectively) using Doppler echocardiography in 20 patients undergoing left heart catheterization for evaluation of coronary artery disease. These intervals were correlated with indices of LV late diastolic stiffness obtained from high-fidelity LV pressure tracings and angiographic volume assessments. The AArp and AAro intervals correlated significantly with LV D...
Action potential changes under varied [Na+]0 and [Ca2+]0 indicating the existence of two inward currents in cells of the rabbit atrioventricular node.
Authors: ERuiz-Ceretti, A PZumino
Journal: Circulation Research (1976)

In the perfused rabbit heart,the upstroke of the transmembrane action potential of fibers of the atrioventricular (AV) node presents two distinct components. The first depends strongly on extracellular sdoium concentration, but the degree to which it is activated is influenced by extracellular calcium, as indicated by the correlation between its Vmax and [Ca2+]0. The second component depends on calcium and sodium concentrations and is blocked by Mn ions. An analysis comparing action potentials from atrial (A), atrionodal (AN), and nodal (N) fibers shows that the second component of the upstroke of the action potential contributes 12%, 27%, and 34% to the total depolarization. The results suggest that the upstroke of the nodal action potential results from the activation of two inward currents, as in ordinary cardiac fibers. We postulate that (1) the degree of steady state inactivation of gNa is larger in N than in A fibers because of the low resting potential of the former, and (2) the contribution of the...
Fetal cardiac and peripheral arterial flow velocity waveforms in intrauterine growth retardation.
Authors: I AGroenenberg, J WWladimiroff, W CHop
Journal: Circulation (1989)

Maximum flow velocity waveforms were studied at the cardiac level (ascending aorta, pulmonary artery, and ductus arteriosus) and at the peripheral level (fetal internal carotid artery, descending aorta, umbilical artery, and maternal uteroplacental artery) in 25 patients with intrauterine growth retardation and 25 normal control subjects matched for gestational age and maternal parity. Gestational age ranged from 27 to 35 weeks (median, 30 weeks). All flow velocity waveforms were obtained with a mechanical sector scanner combined with a pulsed and continuous Doppler system with a carrier frequency of 3.5 and 3.0 MHz. Normal pregnancy was characterized by low fetal and placental vascular resistances. The peak systolic velocity in the ascending aorta was significantly higher compared with the pulmonary artery. In patients with intrauterine growth retardation, reduced end-diastolic flow velocities were documented in fetal descending aorta, umbilical artery, and maternal uteroplacental artery, reflecting rais...
The pressure-flow response of the pulmonary circulation in patients with heart failure and pulmonary vascular disease.
Authors: J SJanicki, K TWeber, M JLikoff, A PFishman
Journal: Circulation (1985)

Although it is well known that the pulmonary circulation is altered in patients with pulmonary arterial or venous hypertension, the resultant hemodynamic behavior has not been systematically studied. We undertook to do so in a group of patients with pulmonary hypertension of diverse etiology. We measured pulmonary arterial (PAP) and occlusive wedge pressures and cardiac output at rest (i.e., standing) and during progressive upright treadmill exercise in 51 patients. Forty-two had chronic, stable, cardiac failure secondary to ischemic, myopathic or valvular heart disease and were grouped according to whether their mean PAP was less than (normotensive) or greater than (hypertensive) 19 mm Hg, and nine had pulmonary vascular disease of diverse etiology and were considered separately. In the majority of patients, we found that irrespective of whether the hypertension was arterial or venous in origin or etiology: the mean PAP-flow relationship was linear; pulmonary capillary wedge pressure was greater than or ...
Differentiation of posterior myocardial infarction from right ventricular hypertrophy and normal anterior loop by echocardiography.
Authors: N EKramer, K KChawla, RPatel, MKhan, TMayer, W DTowne
Journal: Circulation (1978)

The differentiation of posterobasal myocardial infarction (PMI) from either right ventricular hypertrophy (RVH) or normal subjects displaying an anterior loop (AL) by electrocardiography (ECG) or vectorcardiography (VCG) is difficult. M-mode echocardiography (echo) via the anterior and subxiphoid methods has been helpful in defining cardiac chamber size and wall motion abnormalities. We tested whether this relatively more direct method would better separate these entities compared with the other two techniques. ECG and VCG using established criteria failed to distinguish the three conditions effectively. By echo, distinguishing characteristics were observed in each of the groups. Thus, right ventricular diastolic dimension and wall thickness were significantly increased only in the RVH group, echo dimensions and wall motion were normal in the AL group and the posterior left ventricular systolic thickening response and ejection phase indices were significantly reduced only by the subxiphoid method in the P...
Myocardial kinetics of technetium-99m-hexakis-2-methoxy-2-methylpropyl-isonitrile.
Authors: R DOkada, DGlover, TGaffney, SWilliams
Journal: Circulation (1988)

To study the potential usefulness of technetium-99m hexakis-2-methoxy-2-methylpropyl-isonitrile (Tc-MIBI) as a cardiac perfusion imaging agent, the left circumflex coronary arteries of 12 dogs were partially occluded. Eight additional control dogs had no coronary artery stenosis. Myocardial Tc-MIBI activities in the left circumflex and left anterior descending zones were continuously monitored by miniature implantable radiation detectors for 4 hr after administration of the isotope. The dogs were then killed. Serial gamma camera images were also acquired during the study. Heart rate, arterial blood pressure, pressure distal to the stenosis, and cardiac output did not change significantly during the experiment. Microsphere-determined regional myocardial blood flow was significantly reduced in the left circumflex distribution in the 12 dogs with coronary artery stenoses. In the 12 dogs with left circumflex coronary artery stenoses, the 4 hr fractional Tc-MIBI clearances from the normal and ischemic zones we...
A receptor for type I antiarrhythmic drugs associated with rat cardiac sodium channels.
Authors: R SSheldon, N JCannon, H JDuff
Journal: Circulation Research (1987)

We assessed the effects of type I antiarrhythmic drugs on the binding of ligands to receptors on voltage-sensitive sodium channels of rat cardiac myocytes. The radioligand was [3H]batrachotoxinin A 20 alpha-benzoate ([3H]BTXB), a toxin that binds to the sodium channel. The 8 drugs tested inhibited [3H]BTXB binding in a dose-dependent fashion with IC50 values from 1.34 microM for O-demethylencainide to 811 microM for procainamide. A log-log plot of IC50 versus mean therapeutic serum concentration yielded a regression line with slope of 1.17 and r of 0.95. Scatchard analysis of [3H]BTXB binding showed that lidocaine reduced the maximal binding without altering the KD for [3H]BTXB binding, indicating allosteric inhibition. The inhibition by lidocaine of [3H]BTXB binding was reversible within 30 minutes when the samples were diluted from 390 to 39 microM lidocaine. In other studies, the stereoisomers of tocainide were shown to have a threefold to fourfold difference in IC50 for inhibition of [3H]BTXB binding....
Effects of intravascular volume state on the value of pulsus paradoxus and right ventricular diastolic collapse in predicting cardiac tamponade.
Authors: T LCogswell, G ABernath, L SWann, R GHoffman, H LBrooks, H SKlopfenstein
Journal: Circulation (1985)

Both pulsus paradoxus and right ventricular diastolic collapse detected by two-dimensional echocardiography are noninvasive markers of impaired cardiac function in cardiac tamponade, yet the reliability of each may vary with the patient's state of hydration. To examine the relative value of these noninvasive markers at various states of hydration, we studied five chronically prepared, conscious mongrel dogs during 37 episodes of cardiac tamponade at three different intravascular volumes. We continuously measured cardiac output (electromagnetic flowmeter), aortic blood pressure, right atrial blood pressure, intrapericardial pressure, and respirations. Intravascular volume was varied by adjusting the mean right atrial blood pressure to hypovolemic (-2 to -6 mm Hg), euvolemic (0 to 4 mm Hg), or hypervolemic (6 to 10 mm Hg) levels. The sensitivity and specificity of right ventricular diastolic collapse in predicting increases in intrapericardial pressure remained high at all levels of hydration. Pulsus parado...
The nonpharmacologic management of the permanent form of junctional reciprocating tachycardia.
Authors: TGuarnieri, W CSealy, J HKasell, L DGerman, J JGallagher
Journal: Circulation (1984)

The permanent or recurring form of junctional reciprocating tachycardia (PJRT) is an incessant tachycardia that has characteristic clinical and electrophysiologic features of PJRT. Each patient demonstrated near-incessant reciprocating tachycardia with a 1:1 atrioventricular (AV) relationship and with a retrograde P wave (P') occurring closer to the succeeding QRS complexes (i.e., long RP'). With initiation of the tachycardia, there was no prolongation of the PR or AH interval. All patients had evidence of early retrograde atrial activation in their posterior atrial septa and this retrograde limb had properties of decremental conduction. Eight of the nine patients underwent elective surgical ablation of the retrograde limb of tachycardia, and in seven it was successful. Epicardial and endocardial atrial maps recorded during PJRT demonstrated that the site of earliest retrograde activation was in the posterior atrial septum near the coronary sinus orifice. The seven patients in whom surgery was successful ...
Endoscopic Clips Versus Endoscopic Suture for Mucosal Closure after PER-ORAL Endoscopic Pyloromyotomy: a Prospective Single-Center Study
Authors: R Hustak, Z Vackova, J Krajciova, J Spicak, J Martinek
Journal: Endoscopy (2021)

Aims G-POEM is an emerging method for treatment of gastroparesis (GP). Safe mucosal closure is necessary to avoid adverse events. The aim of this prospective study was to compare the effectivity of two closure methods: clips and endoscopic suturing (ES) in patients undergoing G-POEM.
135P The real-world use of tyrosine kinase inhibitors (TKIs) in epidermal growth factor receptor mutated (EGFRm) advanced (stage IIIb/IIIc/IV) non-small cell lung cancer (NSCLC) patients
Authors: J. Subramanian, Y-L. Choi, T-Y. Chou, J. Gregg, R. Hui, N. Leighl, A. Marchetti, N. Navani, T. Bailey, M. Silvey, R. Makin, D.A. Kahangire, M. Chau, A. Taylor, F. Griesinger
Journal: Journal of Thoracic Oncology (2021)
Preservation of atrioventricular nodal conduction during radiofrequency current catheter ablation of midseptal accessory pathways.
Authors: K HKuck, MSchlüter, SGürsoy
Journal: Circulation (1992)

BACKGROUNDSeptal accessory atrioventricular (AV) pathways may be located in close vicinity of the His bundle-AV nodal conduction system. Attempts at surgical or electrical interruption of these pathways may therefore result in impairment of normal AV conduction. This study focuses on a subset of septal pathways with an atrial insertion located inside the triangle of Koch. In this study, they were called midseptal.METHODS AND RESULTSSix patients with a midseptal accessory pathway (mean +/- SD age, 40 +/- 12 years; five with Wolff-Parkinson-White syndrome and one with a concealed accessory pathway) underwent attempts at ablation of their pathway using 500-kHz radiofrequency current applied to the atrial insertion of the accessory connection. Guided by the recording of accessory pathway activation potentials, the ablation catheter was positioned in all patients in an area bounded anteriorly by the tip electrode of the His bundle catheter and posteriorly by the coronary sinus ostium. All pathways were succe...
Noninvasive recording of His-Purkinje activity in patients with complete atrioventricular block. Clinical application of an "automated discrimination circuit".
Authors: HTakeda, KKitamura, TTakanashi, TTokuoka, HHamamoto, TKatoh, INiki, YHishimoto
Journal: Circulation (1979)

In seven patients with complete atrioventricular (AV) block, His bundle electrograms (HBEs), standard ECG recordings, bipolar esophageal ECGs and highly amplified, filtered, bipolar chest lead ECGs were simultaneously recorded. The filtered chest lead ECG was averaged to determine His-Purkinje activity (HPA). A simplified device, the automated discrimination circuit, was used to selectively eliminate the superimposed atrial and ventricular potentials that are characteristic of complete AV block and unsuitable for signal averaging. The processed chest lead ECG was amenable to conventional techniques of signal averaging. In four patients with block proximal to the AV node diagnosed by HBE, there was no activity after the P wave in the surface-averaged ECGs. HPA was consistently recorded before the QRS in the surface-averaged ECG. The measurements of the HV and HPA-V intervals were very close, with a difference of less than 2 msec. Three patients with block distal to the His bundle by HBE showed a loss of ...
Association of WIC Participation and Electronic Benefits Transfer Implementation
Authors: Aditi Vasan, Chén C. Kenyon, Chris Feudtner, Alexander G. Fiks, Atheendar S. Venkataramani
Journal: JAMA Pediatrics (2021)

The Special Supplemental Nutrition Program for Women, Infants, and Children (WIC) is an important source of nutritional support and education for women and children living in poverty; although WIC participation confers clear health benefits, only 50% of eligible women and children currently receive WIC. In 2010, Congress mandated that states transition WIC benefits by 2020 from paper vouchers to electronic benefits transfer (EBT) cards, which are more convenient to use, are potentially less stigmatizing, and may improve WIC participation.
Neuronal and adrenomedullary catecholamine release in response to cardiopulmonary bypass in man.
Authors: J GReves, R BKarp, E EButtner, STosone, L RSmith, P NSamuelson, G RKreusch, SOparil
Journal: Circulation (1982)

Cardiopulmonary bypass (CPB) alters systemic hemodynamics and affects several biochemical systems involved in cardiovascular regulation. We investigated the changes in levels of circulating epinephrine (E) and norepinephrine (NE) and related them to events during CPB. Twenty-eight patients undergoing various surgical procedures were studied. Plasma E and NE were determined by radioenzymatic assay at eight stages of the operation. A ninefold increase in arterial E (from 75 +/- 13 to 708 +/- 117.3 pg/ml) occurred from prebypass (stage 1) measurements to the end of aortic cross-clamping (stage 4). The values at stage 4 were significantly higher (p less than 0.05) than at all other stages. E decreased rapidly, to 360 +/- 84.3 pg/ml, after myocardial and pulmonary reperfusion (stage 5). Arterial NE increased twofold from stage 1 to stage 4 (from 426 +/- 66.9 to 825 +/- 84.2, p less than 0.05). The increase in NE from initial CPB values (stage 2) to 30 minutes of aortic cross-clamping (stage 3) was associated w...
Epidermotropic Eccrine Carcinoma
Journal: JAMA (1963)

I● 緒 言 PinkusおよびMehregan (1963)は,腹部から下肢 にかけて,広汎な皮膚腫瘍を発来した1例の組織学的検 索によって, Paget病様の特異な表皮内腫瘍巣形成を 認め,恐らく足部に原発した汗腺由来の悪性腫瘍の表皮 内転移であろうとして, epidermotropic eccrine carcinomaとして報告した.そして,原発巣の詳細な検討は できなかつたが,転移巣の組織像がeccrine poroma に 似ていることから,原発腫瘍が悪性のeccrine poroma である可能性を推定している.われわれも最近Pinkus らの例と全く相似の症例を経験し,かつ剖検する機会を 得たので報告する.なおこの症例については,教室の中 川2)らが乳房外Paget病の1異型として,第65回日本皮 膚科学会総会で報告し,また第176回日本皮膚科学会北 海道地方会で, epidermotropic eccrine carcinoma とし て赤野3)らが報告したのち,同じ題名で臨床皮膚科に記 載したほか,三浦がミュンヘンにおける第13回国際皮膚 科会議で発表したことをお断わりしておく. n● 症 例 症 例:69才,男,会社員.初診ご昭和38年4月22 口.既往歴,家族歴には特記すべきことはない. 昭和26年頃に,右下腿後方中央に小豆大の柔かい紅色 の丘疹を生じ,自宅で軟膏療法を行なっていたところ, 次第に増大して,昭和38年(初発の丘疹に気付いてから 12年後)には難卵大の腫瘍を形成した. 初診時の所見は,6×5Cm大の花キャベツ状の腫瘍 で,直径約3Cmの茎で皮膚にっながっている.易出血性 で,悪臭のある分泌物をもらす.周囲の皮膚には浸潤は ない.右下肢には強い浮腫が認められる.両側里蹊部リ y・ 節は,数個が小指頭大に腫脹していた. 5月中旬に,周辺の健常皮膚を含めて腫瘍を切除し, 同側大腿内側から採皮して中間層植皮を行なった.当時 の組織学的診断はbaso-squamous cell carcinomaであ った.同時に摘除したリン節に,組織学的に腫瘍細胞. の存在を証明したので,この部にレソトゲソ照射を行な った( 250rX 6回). U月頃から,右大腿内側の採皮部位がケロイド状に隆 起し,ついで現状の小丘疹が多発した.組織学的に腫瘍 の転移と考えられたので,レソトゲソ照射( 250r x24 回,総量6,000r)を行なったところ,皮疹は扁平化し たがビラソ面を形成した.39年2月頃から右下腿にも恚 状の丘疹が散在性に出現し,次第に数を増して,原発腫 瘍切除後の植皮部にも生ずるに至った.制癌剤を使川し たが,丘疹はビラソ而を形成し,漸次左下肢,陰部,腹’ 部にも新らしtヽ丘疹,浸潤,色素沈着を生じ,広汎なビ ラソ面を作り,陰嚢部では一見Paget病を思わせる所見 を呈した.同年7月悪液質に陥って死亡.た. 剖検所見:皮膚原発巣には皮膚移植が施されている が,この部を含めて,両下肢,陰部,下腹部にわたって 広汎なビラy,丘疹形成がみられており,腫瘍性浸潤は きわめてビマソ性かつ表在性である.腫瘍転移は蝋蹊部ミ リyパ節のほか,大動脈周囲のリンパ節に若干存在して いる.その他の所見としては,全身的な著明な動脈硬化 症があって,大動脈には潰瘍形成,血栓形成をともなつ・ でいた.腎は老人性萎縮腎の像を呈していた.剖検診断 は,1)皮膚原発癌の右下肢,会陰部,陰嚢,陰茎,左 大腿部,下腹部皮膚表層へのビマン性浸潤,2)爪蹊と