A Preliminary Exploration of the Placental Position Influence on Uterine Electromyography Using Fractional Modelling

The uterine electromyogram, also called electrohysterogram (EHG), is the electrical signal generated by uterine contractile activity. The EHG has been considered an expanding technique for pregnancy monitoring and preterm risk evaluation. Data were collected on the abdominal surface. It has been speculated the effect of the placenta location on the characteristics of the EHG. In this work, a preliminary exploration method is proposed using the average spectra of Alvarez waves contractions of subjects with anterior and non-anterior placental position as a basis for the triple-dispersion Cole model that provides a best fit for these two cases. This leads to the uterine impedance estimation for these two study cases. Non-linear least square fitting (NLSF) was applied for this modelling process, which produces electric circuit fractional models' representations. A triple-dispersion Cole-impedance model was used to obtain the uterine impedance curve in a frequency band between 0.1 and 1 Hz. A proposal for the interpretation relating the model parameters and the placental influence on the myometrial contractile action is provided. This is the first report regarding in silico estimation of the uterine impedance for cases involving anterior or non-anterior placental positions.info:eu-repo/semantics/publishedVersio

Myocarditis: Medical education [Miyokardit]

Myocarditis is an inflammatory disorder of the myocardium with necrosis of myocytes and associated inflammatory infiltrate. Although the etiological agent is usually a virus, some bacteria, fungi, autoimmune disorders and medical drugs may also be implicated. Myocarditis has a variable clinical manifestation from latent to very severe clinical forms, such as acute congestive heart failure and sudden death. Scintigraphy, echocardiography and cine magnetic resonance angiography are useful methods to identify myocarditis. Endomyocardial biopsy, using the Dallas criteria for histopathological classification, has remained the gold standard for the diagnosis of acute myocarditis. In this review, pathological mechanisms, modalities of diagnosis and treatment strategies of myocarditis are discussed. Copyright © 2006 by Türkiye Klinikleri

Endothelial ion channels and their functions [Endoteldeki· i·yon kanallari ve i·şlevleri·]

Endothelium produces endothelium-drived relaxing factor (EDRF), now widely accepted to be nitric oxide (NO), prostacyclin (PGIi), endothelium-derived hyperpolarizing factor (EDHF), endothelin, ATP and molecules Involved In cell proliferation. Endothelial cells (ECs) are classed as nonexcitable cells because they do not generate action potential. Ionic channels in vascular endothelium play significant roles, controlling resting potential, signal transduction and stimulus-secretion coupling. In a general sense, in both smooth muscle cells and ECs, the activities of ion channels are present and the resultant membrane potential of these cell determine the blood flow. Channel currents in ECS are influenced by released vasoactive factors, mechanical forces such as blood flow and pressure, and metabolic conditions. To date, most electrophysiological data have been obtained from large vessel ECs, often in culture. Resting potential in culture isolated EC s recorded with microelectrodes are -40 to -60 mV. The surface area of ECs is between 1000-2000 µ2, membrane capacity (Cm) 1 µF/cm2 and cell capacity (10-50 pF)

Hydatid disease presenting as cardiac tamponade: A case history

PubMedID: 8678335Although hydatid disease has been reported in almost all human tissues, cardiac involvement is uncommon. The authors report a case of cardiac hydatid disease presenting with cardiac tamponade. The diagnostic value of transthoracic and transesophageal echocardiography, computed tomography, and angiography in hydatid heart disease is also discussed

Cardiomyopathy and atrioventricular block in Emery-Dreifuss muscular dystrophy: A case report

PubMedID: 11863303A 32-year-old woman is described as having the following characteristics of Emery-Dreifuss muscular dystrophy: humeroperoneal muscular atrophy and weakness, neck and elbow contractures with sinus bradycardia, first-degree atrioventricular block, and dilated cardiomyopathy. The biopsy specimen of skeletal muscle showed dystrophic character; a cardiac endomyocardial biopsy specimen showed adipose tissue infiltration and deposition of antihuman IgG. Emery-Dreifuss muscular dystrophy is an X-linked recessive myopathy. The patient had no familial background of the disease. This patient might have a sporadic inheritance pattern with severe cardiac involvement

Production of porous ceramic from clinoptilolite incorporating aluminum powder

In this study, production of porous ceramic from clinoptilolite incorporating aluminum powder at various sintering temperatures was investigated. The mixtures were sintered at 1150, 1200, 1250 and 1300 °C for 1 h in air atmosphere. SEM and XRD analyzes were conducted to observe the microstructural evolution and the phase composition, respectively. The DSC/TG analyzes of the clinoptilolite and aluminum powder mixture indicated that 1150 °C was a significant temperature at which oxidation of molten aluminum enhanced and the softening of the clinoptilolite began. The progress in oxidation of aluminum with increasing temperature led to corundum phase crystallization while the amount of cristobalite decreased. Aluminum distribution in the ceramic matrix began at 1200 °C but pore channels with very smooth surfaces were obtained at 1250 °C. At this temperature, the pores interconnected to each other had narrow pore size distribution (4–180 μm) with low friction coefficient of 0.64 resulting from enhanced corundum phase formation in the structure. Results showed that the porous ceramic sintered at 1250 °C with 32.8% apparent porosity and a pure water permeability of ~2050 L/(m2•hr•bar) promises great potential for use as a filtering media and/or support. © 201

Left ventricular systolic and diastolic functions in patients with sickle cell anemia

The aim of this study was to evaluate the left ventricular systolic and diastolic functions in patients with sickle cell anemia. Fifty-four patients (34 male, 20 female, mean age 22.6 ± 7.3 years) and 23 healthy persons (12 male, 11 female, mean age 26.7 ± 6.8 years) were studied. After clinical examination and routine biochemical evaluation by a hematologist, patients with sickle cell anemia were admitted to the study. M-mode and 2-dimensional and Doppler echocardiographic measurements of patients and controls were performed according to criteria of the American Echocardiography Society. The values of the patient groups were compared with the values of normal healthy subjects (controls). Left ventricular systolic and diastolic diameters of sickle cell patients were greater than those of controls (p < 0.001). All of the sickle cell anemia patients had reduced systolic cardiac function (EF: 0.57 ± 0.1 vs 0.63 ± 0.06 and FS: 0.30 ± 0.06 vs 0.34 ± 0.04, p < 0.02) and abnormal diastolic left ventricular function parameters compared with the control group (IRT: 114 ± 20 msec vs 65 ± 7 msec, p < 0.0001; E/A ratio: 1.2 ± 0.5 vs 1.6 ± 0.04, p < 0.01). Left ventricular mass (LVM) was greater in patients than in controls (222 ± 78 g vs 177 ± 46 g, p < 0.01). Left ventricular systolic and diastolic functions were abnormal in patients with sickle cell anemia, and the left ventricular mass was greater in the patients compared with controls

Aorto-left atrial fistula with bicuspid aortic valve and coronary artery origin anomaly

PubMedID: 9066423Published reports of aorto-left atrial fistula are very rare. We report a 20-year-old man who had an aorto-left atrial fistula with bicuspid aortic valve and coronary artery origin anomaly. Because acquired etiologic factors were not detected, we believe that the lesions were structural defects of congenital origin