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PLoS Biol 2018 Aug 27;16(8):e2006062. Epub 2018 Aug 27.

Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, United States of America.

Turnovers of sex-determining systems represent important diversifying forces across eukaryotes. Shifts in sex chromosomes-but conservation of the master sex-determining genes-characterize distantly related animal lineages. Yet in plants, in which separate sexes have evolved repeatedly and sex chromosomes are typically homomorphic, we do not know whether such translocations drive sex-chromosome turnovers within closely related taxonomic groups. Read More

J Atr Fibrillation 2017 Oct-Nov;10(3):1656. Epub 2017 Oct 31.

Division of Cardiology, Queen's University, Kingston, Ontario, Canada.

A case of a patient with Atrial Fibrillation and intermittent wide complex beats. What's the mechanism? Read More

Card Electrophysiol Clin 2017 09 27;9(3):453-460. Epub 2017 Jun 27.

Heart and Vessels Department, University of Florence, Largo Brambilla, 3, 50134 Florence, Italy; IRCCS Multimedica, Cardiology Department, Via Milanese, 300, 20099 Sesto San Giovanni, Italy.

The ventricular conduction system starts below the His bundle, where it bifurcates into the right and left bundle branches that taper out to the subendocardial Purkinje network, which activates the ventricular myocardium. This system is responsible for the synchronized and almost simultaneous activation of both ventricles. On the surface electrocardiogram, the ventricular conduction system lies in the terminal portion of the PR interval, whereas the QRS complex composed of the electrical currents originating from ventricular depolarization. Read More

West Indian Med J 2014 Aug 30;63(4):382-3. Epub 2013 Dec 30.

Emergency Medicine Division, Department of Surgery, Radiology, Anaesthesia and Intensive Care, The University of the West Indies, Kingston 7, Jamaica, West Indies.

J Chem Ecol 2014 Feb 30;40(2):128-35. Epub 2014 Jan 30.

Department of Biological Sciences, University of Pittsburgh, Pittsburgh, PA, 15260, USA,

Hyperaccumulation is the phenomenon whereby plants take up and sequester in high concentrations elements that generally are excluded from above-ground tissues. It largely is unknown whether the metals taken up by these plants are transferred to floral rewards (i.e. Read More

BMJ Case Rep 2013 May 24;2013. Epub 2013 May 24.

Department of Cardiology, Sri Jayadeva Institute of Cardiovascular Sciences and Research, Bengaluru, Karnataka, India.

Acta Clin Croat 2010 Mar;49(1):99-100

Am J Geriatr Cardiol 2004 Sep-Oct;13(5):285

Cardiology Division, University of Massachusetts Medical School, University Campus, 55 Lake Avenue North, Worcester, MA 01655, USA.

J La State Med Soc 2004 May-Jun;156(3):159-62

Louisiana State University, School of Medicine, New Orleans, USA.

In the presence of atrial fibrillation, impulses of supraventricular origin that are transmitted through the ventricles during periods of relative refractoriness to impulse conduction exhibit anomalous configurations. These "aberrant beats" can be difficult to distinguish from ventricular ectopic beats, and groups of aberrant beats may be mistaken for ventricular tachycardia. Richard Ashman, PhD, a physiologist at Louisiana State University School of Medicine in New Orleans, noted that ventricular refractoriness varied with the lengths of cardiac cycles; that aberrant beats typically ended short cycles following long cycles; and that aberrant beats often have a right bundle branch block configuration. Read More

Implant Dent 2000 ;9(1):90-5

New York University College of Dentistry, Arthur Ashman Department of Implant Dentistry, USA.

The mandibular deformation as a result of jaw movement from rest position has been studied and documented by other authors. Here, we report that there is a possible correlation between this phenomenon and the discomfort experienced by a patient rehabilitated with implant-supported restoration for the mandibular arch during function. The recovery from pain and symptoms was achieved only after splitting the prosthesis into three sections. Read More

AJR Am J Roentgenol 2000 Aug;175(2):541-4

Department of Radiology, The Ohio State University Medical Center, Columbus 43210, USA.

Objective: "Satisfaction of search" describes a situation in which the detection of one radiographic abnormality interferes with that of others. This phenomenon has not been investigated for the interpretation of skeletal radiographs. We determined whether satisfaction of search occurs in the interpretation of conventional radiographs of the musculoskeletal system. Read More

Ital Heart J Suppl 2000 May;1(5):632-40

Unità Operativa di Cardiologia, Ospedale Santa Caterina Novella, Galatina, LE.

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and it is associated mainly with a significant mortality and morbidity. The purpose of this report is to focus on the major electro-cardiological aspects of AF and to provide some elements useful in the understanding of its pathophysiology. Experimental and clinical studies have shown that AF is maintained by multiple reentrant wavelets within the atrial muscle. Read More

J Immunol 1996 Jul;157(1):5-11

Iowa City DVA Medical Center, Iowa City 52242, USA.

By linking surface Ig to the FcR Fc gamma RII on the mouse B lymphocyte surface, whole anti-Ig has been shown to block cell cycle entry and subsequent Ab production, a phenomenon called the "Fc receptor off-signal." IL-4 or blocking Ab to Fc gamma RII, present with whole anti-Ig, restores cell cycle progress to the levels observed with F(ab')2 anti-Ig. The current study demonstrates that under "off-signal" conditions with whole anti-Ig, the early entry of B cells into apoptosis was accelerated relative to medium alone or equimolar F(ab')2 anti-Ig. Read More

Am Heart J 1994 Jul;128(1):205-9

J Cardiovasc Electrophysiol 1993 Aug;4(4):459-66

Department of Cardiology, Thoraxcenter, University Hospital, Groningen, The Netherlands.

Introduction: The mechanism of wide QRS complex tachycardias during dofetilide infusion was studied in a patient with atrial fibrillation.

Methods And Results: Endocardial recordings from the intraventricular conduction system showed that dofetilide caused "classic" aberrant conduction (Ashman phenomenon, typical QRS morphology) at high prematurity ratios (preceding interval = 1.78 x coupling interval--290), thus mimicking ventricular ectopy. Read More

Am J Cardiol 1989 Apr;63(12):886-90

Department of Medicine, University of Rochester Medical Center, New York 14642.

J Am Coll Cardiol 1985 Feb;5(2 Pt 1):311-7

Verapamil, a calcium channel blocking agent, has been demonstrated to have depressive effects on the atrioventricular (AV) node but not anomalous AV bypass tracts. Of 39 patients with AV reciprocating tachycardia utilizing left-sided bypass tracts for retrograde conduction, intravenous infusion of verapamil (0.15 mg/kg) terminated the tachycardia in 31 patients. Read More

J Immunogenet 1984 Apr;11(2):135-47

Spleen cells from 30 individual murine irradiation chimeras of the type (P1 X P2)F1----P1 were compared in a rosetting assay for H-2K and H-2D cell surface antigen expression with normal (P1 X P2)F1 hybrid controls. Eleven out of the 30 chimeras were in the normal range, but the other 19 differed from F1 controls by 4- to 100-fold in endpoint titre for at least one H-2K or H-2D antigen. Every possible class of variation was found, i. Read More

Heart Lung 1982 Jul-Aug;11(4):381-2

Acta Cardiol 1982 ;37(3):175-81

The electrocardiograms of 29 patients with atrial fibrillation and aberrancy (Ashman phenomenon) were studied. The length of the cycles manifesting aberrancy (R-RA) varied from 270 to 520 msec (mean 372 +/- 55). It correlated negatively with the heart rate (r-0. Read More

Med Times 1978 Sep;106(9):96-100

Chest 1977 May;71(5):651-8

Recent studies emphasize the importance of heart rate in the genesis of ventricular arrhythmias during myocardial ischemia. The role of alterations in rhythm has not previously been systematically investigated. In 20 dogs subjected to acute myocardial ischemia and crushing of the sinus node, standard electrocardiographic leads were recorded, as well as His bundle and epicardial electrograms from the normal and ischemic areas. Read More