Search results for " conduction"
showing 10 items of 373 documents
4-Aminopyridine antagonizes the inhibitory effect of pentobarbital on acetylcholine release in the heart
1980
Effects of pentobarbital on acetylcholine (ACh) release, force of contraction and nervous conduction were studied in isolated heart preparations and in cervical vagus nerves, respectively. 4-Aminopyridine and tetracaine were used as pharmacological tools to eludicate the mode of action of pentobarbital. 1. 4-Aminopyridine (10−4 M) markedly increased the overflow of ACh from the isolated chicken heart evoked by electrical stimulation (1–50 Hz, 1 ms, 40 V) of the cervical vagus nerves. This effect of 4-aminopyridine was highest at low frequencies of stimulation (+ 226% at 1 Hz) and declined with increasing frequencies to reach a minimum augmentation of 22% at 30 Hz. 2. Pentobarbital and tetra…
Analysis of the extension of Q-waves after infarction with body surface map: relationship with infarct size.
2006
We aimed to characterize the extension of Q-waves after a first ST-segment elevation myocardial infarction using body surface map (BSM) and its relationship with infarct size quantified with cardiovascular magnetic resonance imaging (CMR).Thirty-five patients were studied 6 months after a first ST-segment elevation myocardial infarction (23 anterior, 12 inferior). All cases had single-vessel disease and an open artery. The extension of Q-waves was analyzed by means of a 64-lead BSM. Infarct size was quantified with CMR. Absence of Q-waves in BSM was observed in 5 patients (14%), 2 of whom (40%) had1 segment with transmural necrosis. Absence of Q-waves in 12-lead ECG was observed in 8 patien…
Generalised sensory system abnormalities in amyotrophic lateral sclerosis: a European multicentre study.
2007
International audience; BACKGROUND: Amyotrophic lateral sclerosis (ALS) is defined as a disease of the motor neurones, although several studies indicate involvement of the sensory nervous system. AIM: To evaluate the sensory nerve conduction studies (NCS) in 88 patients with ALS as part of a European multicentre study. METHODS: Seven European clinical neurophysiologists examined consecutive series of ALS patients. The examinations were peer reviewed, and the diagnosis of ALS was confirmed clinically. RESULTS: 20 (22.7%) patients with ALS had sensory NCS abnormalities in at least one nerve. Of those, 11 (12.5% of all patients) obtained an additional peer review diagnosis of electrophysiologi…
Morphometric analysis of cardiac conduction fibers in horses and dogs, a comparative histological and immunohistochemical study with findings in huma…
2021
Abstract The principal function of the ventricular conduction system is rapid electrical activation of the ventricles. The aim of this study is to conduct a morphometric study to pinpoint the morphological parameters that define cardiac conduction cells, allowing us to distinguish them from other cells. Five male horse hearts and five male dog hearts were used in the study. The hearts were fixed in a 5% formaldehyde solution. Histological sections of 5 μm thickness were acquired and stained with hematoxylin-eosin and Masson's trichrome and cardiac conduction cells and their junctions were identified by desmin, connexin 40 and a PAS method. We found statistically significant differences in c…
Identification to cardiac conduction cells in humans and pigs according to their zonal distribution, using histological, immunohistochemical and morp…
2021
Abstract Histologically, the cardiac conduction network is formed of electrically isolated subendocardial fibers that comprise specialized cells with fewer myofibrils and mitochondria than cardiomyocytes. Our aim is to uncover regional variations of cardiac conduction fibers through histological and morphometric study in a porcine and human model. We analyzed five male adult human hearts and five male pig hearts. The left ventricles were dissected and sectioned in the axial plane into three parts: basal, middle third and apex regions. Cardiac conduction fibers study was carried out using hematoxylin-eosin and Masson's trichrome staining, and cardiac conduction cells and their junctions were…
Rare association of herpes simplex virus IgM-specific antibodies and Guillain-Barré syndrome successfully treated with plasma exchange and immunosupp…
1985
Herpes simplex virus (HSV) has been associated with various neurological disorders. In contrast, HSV infection is very rarely found in acute polyneuroradiculitis. In this report, a patient is described with a severe course of Guillain-Barr¿ syndrome (GBS). HSV IgM-specific antibodies and a rise of complement-fixation antibodies were detected. During the acute phase of neurologic syndrome, a nerve biopsy showed myelin damage and IgM deposits on the inner layer of the perineurium. Plasma exchange, in combination with immunosuppression, was successfully applied as a treatment in the relapsing course of GBS. Finally, after recovery, HSV-specific IgM antibodies disappeared.
The Effects of Selective Stellate Ganglion Manipulation on Ventricular Refractoriness and Excitability
1992
The effects of selective stellate ganglion stimulation or stellectomy on ventricular excitability were studied in 30 open chest mongrel dogs anesthetized with alpha-chloralose. The effective refractory period (ERP) and strength interval curves (stimulus intensity [S2] = twice the diastolic threshold [ERP], and 2, 3, 5, 7, and 14 mA) were determined using bipolar epicardial electrodes placed in the mid-anterior wall of the right ventricle (RV) and the mid-posterolateral wall of the left ventricle (LV) during left stellate ganglion stimulation (LSGSt, n = 8) or right stellate ganglion stimulation (RSGSt, n = 8), or after left stellectomy (LSGEx, n = 7) or right stellectomy (RSGEx, n = 7). LSG…
Investigations of the sensory blockade effect of perineurally injected ethanol on the tail nerve of the mouse.
1976
The effect of an alcohol block on the conduction of sensory stimuli in the tail nerve of the mouse was investigated using the perineural injection of solutions of ethanol (35, 40 and 45%). One hundred and fifty white mice of either sex were given 2 X 0.03 ml of the relevant alcohol solution into both sides of the tail. Before and after the injections repeated sensory conduction measurements were made using the rat tail method. Using 35% ethanol a temporary block of pain conduction could be achieved in both sexes. By increasing the concentration to 40 or 45%, a prolongation of the blocking effect and an increase in the accompanying increase of the pain threshold was observed in some animals.…
ALS-Related Mutant FUS Protein Is Mislocalized to Cytoplasm and Is Recruited into Stress Granules of Fibroblasts from Asymptomatic FUS P525L Mutation…
2017
Background: Amyotrophic lateral sclerosis (ALS) shows a strong genetic basis, with SOD1, FUS, TARDBP, and C9ORF72 being the genes most frequently involved. This has allowed identification of asymptomatic mutation carriers, which may be of help in understanding the molecular changes preceding disease onset. Objectives: We studied the cellular expression of FUS protein and the effect of heat-shock-and dithiothreitol-induced stress in fibroblasts from FUS P525L mutation carriers, healthy controls, and patients with sporadic ALS. Methods: Western blots and immunocytochemistry were performed to study the subcellular localization of FUS protein. Control and stressed cells were double stained with…
Rate vs. rhythm control and adverse outcomes among European patients with atrial fibrillation
2018
Aim The impact of rate and rhythm control strategies on outcomes in patients with atrial fibrillation (AF) remains controversial. Our aims were: to report use of rate and rhythm control strategies in European patients from the EURObservational Research Program AF General Pilot Registry. Secondly, to evaluate outcomes according to assigned strategies. ........................................................................................................................................................... Methods and results Use of pure rate and rhythm control agents was described according to European regions. 1-year follow-up data were reported. Among rate control strategies, beta-blockers …