Evaluation of Atrial Electromechanical Delay in Children with Obesity.

Background and Objective: Childhood obesity is one of the worldwide health problems with an increasing prevalence and accompanied by severe morbidity and mortality. It is a serious predisposing risk factor especially for the development of cardiovascular diseases and arrhythmias. Electromechanical delay (EMD) is known to be a predictor for the development of atrial fibrillation (AF). Our study aims to investigate whether EMD, which is a predictor of AF, prolongs in obese children or not. MATERIAL AND METHODS: The study included 59 obese patients aged between 8-18 years and 38 healthy patients as the control group with a similar age and gender. All the individuals underwent transthoracic echo and tissue Doppler echocardiography. Systolic and diastolic left ventricular (LV) functions, inter- and intra-atrial electromechanical delay were measured by tissue Doppler imaging (TDI) and conventional echocardiography. RESULTS: Obese patients had significantly lengthened P-wave on surface ECG to the beginning of the late diastolic wave (PA) lateral, PA septum, intra- and inter-atrial electromechanical delays when compared with the control group (p < 0.001, p = 0.001, p < 0.001 and p < 0.001, respectively) Inter-atrial EMD and intra-atrial EMD correlated positively with body mass index (BMI) values (r = 0.484, p < 0.001 and r = 0.376, p = 0.001; respectively) BMI was significantly related with inter-atrial EMD (ß = 0.473, p < 0.001) However, there was no relationship between inter-atrial EMD and serum glucose and platelet count. CONCLUSION: In our study, we declared that electromechanical delay was increased in obese children when compared to the control group and intra- and inter-atrial electromechanical delay was in correlation with body mass index. Furthermore, we discovered that BMI is an independent predictor of the inter-atrial EMD in obese children.

Quantitation of 24-Hour Moisturization by Electrical Measurements of Skin Hydration.

PURPOSE: The purpose of this study was to quantify the effects of several moisturizers on hydration of the stratum corneum by measuring their effect on electrical conductance over a 24-hour period. DESIGN: Double-blind, randomized controlled trial. SUBJECTS AND SETTING: Twenty-five healthy female volunteers aged 18 to 65 years with dry skin on the lower legs and no other known dermatologic pathology participated in the study. Additional exclusion criteria were pregnant or taking anti-inflammatory steroids. The study was carried out in a clinical research facility in Winnipeg, Manitoba, Canada. METHODS: Subjects underwent a 3-day conditioning period using a natural soap bar on the lower legs and no application of moisturizer to the skin. Participants then came to the test site and equilibrated for at least 30 minutes under controlled conditions of temperature and humidity. After baseline hydration measurements on test sites on the lower legs of each subject, a single application of each of 5 test products at a dose of 2 mg/cm was made. Skin hydration was assessed by electrical conductance measurements with a specialized probe. The probe was briefly placed on the skin surface with light pressure, and the measurement recorded in units of microsiemens (µS). Conductance was measured at 2, 4, 6, 8, and 24 hours after product applications. RESULTS: Although all but 1 of the test products increased conductance at 2 hours, only 2 moisturizers containing high levels of glycerin (products C and E) maintained increased conductance relative to baseline at 24 hours, +37.8 (P < .001) and +103.5 (P < .001), respectively. CONCLUSIONS: Moisturizers containing high levels of glycerin can provide a measurable moisturization benefit as determined by skin conductance for at least 24 hours after a single application.

Heterogeneous composition of voltage-dependent K(+) currents in hepatic stellate cells.

PURPOSE: Hepatic stellate cells (HSC) are a type of pericyte with varying characteristics according to their location. However, the electrophysiological properties of HSC are not completely understood. Therefore, this study investigated the difference in the voltage-dependent K(+) currents in HSC. MATERIALS AND METHODS: The voltage-dependent K(+) currents in rat HSC were evaluated using the whole cell configuration of the patch-clamp technique. RESULTS: Four different types of voltage-dependent K(+) currents in HSC were identified based on the outward and inward K(+) currents. Type D had the dominant delayed rectifier K(+) current, and type A had the dominant transient outward K(+) current. Type I had an inwardly rectifying K(+) current, whereas the non-type I did not. TEA (5 mM) and 4-AP (2 mM) suppressed the outward K(+) currents differentially in type D and A. Changing the holding potential from -80 to -40 mV reduced the amplitude of the transient outward K(+) currents in type A. The inwardly rectifying K(+) currents either declined markedly or were sustained in type I during the hyperpolarizing step pulses from -120 to -150 mV. CONCLUSION: There are four different configurations of voltage-dependent K(+) currents expressed in cultured HSC. These results are expected to provide information that will help determine the properties of the K(+) currents in HSC as well as the different type HSC populations.

Heterogeneous Composition of Voltage-Dependent K+ Currents in Hepatic Stellate Cells

PURPOSE: Hepatic stellate cells (HSC) are a type of pericyte with varying characteristics according to their location. However, the electrophysiological properties of HSC are not completely understood. Therefore, this study investigated the difference in the voltage-dependent K(+) currents in HSC. MATERIALS AND METHODS: The voltage-dependent K(+) currents in rat HSC were evaluated using the whole cell configuration of the patch-clamp technique. RESULTS: Four different types of voltage-dependent K(+) currents in HSC were identified based on the outward and inward K(+) currents. Type D had the dominant delayed rectifier K(+) current, and type A had the dominant transient outward K(+) current. Type I had an inwardly rectifying K(+) current, whereas the non-type I did not. TEA (5mM) and 4-AP (2mM) suppressed the outward K(+) currents differentially in type D and A. Changing the holding potential from -80 to -40mV reduced the amplitude of the transient outward K(+) currents in type A. The inwardly rectifying K(+) currents either declined markedly or were sustained in type I during the hyperpolarizing step pulses from -120 to -150mV. CONCLUSION: There are four different configurations of voltage-dependent K(+) currents expressed in cultured HSC. These results are expected to provide information that will help determine the properties of the K(+) currents in HSC as well as the different type HSC populations.

Utilidad del módulo de «Biofeedback» DiacontrolTM en la programación automática de la conductividad plasmática y la transferencia de masa iónica / Biofeedback diacontrolTM module in the automatic programation of plasmatic conductivity ad ionic mass transfer

La utilización de perfiles descendentes de conductividad en el dializado (CD) ha disminuido el número de complicaciones intradiálisis. No obstante, la presencia de una mayor concentración de sodio puede originar un balance positivo de este catión y favorecer los episodios de sed y el desarrollo de hipertensión arterial. El objetivo de este estudio fue comparar la tolerancia, así como la evolución de la Conductividad Plasmática (CP) y la Transferencia de Masa lónica (TMI), al pasar de un tipo se sesión con alto contenido en Na (perfiles de CI) y UF) a otro tipo de sesión que emplea un sistema de «biofeedback» (DiacontroITM ) y repetir el proceso inverso. Se han estudiado 120 sesiones de diálisis en 10 pacientes durante cuatro periodos de tratamiento (PF1-DC1-DC2-PF2). Durante los períodos PF1 y PF2 los pacientes se dializaban con perfiles logarítmicos descendentes de conductividad (C1) al inicio de la sesión 15,7 mS/cm, a la mitad 14,4 mS/cm y 13,8 mS/cm al final) y UF (1,7 I/h al inicio y 0,1 I/h al final) y en los períodos DC1 y DC2 se realizaron con el sistema DiacontroITM, fijando la CP final en 14 mS/cm. No se detectaron diferencias significativas en la TAS, TAM y TAD pre o postsesión entre los cuatro períodos. El porcentaje de sesiones con al menos un episodio de hipotensión fue del 33,3% en PF1, 20% en DC1, 23,3% en DC2 y 26.6% en PF2 (ns). El descenso del VP fue de -4,04 +- 3,26% en PF1, -6,53 +- 3,31% en DC1, -6,67 +- 3,12% en DC2 y 4,36 +- 2,7% en PF2 (p < 0,00l PF1 y PF2 vs DC1 y DC2). La CP fue significativamente superior tanto a los 30’, mitad de sesión, post-HD, así como a lo largo de toda la sesión, en los períodos PF1 y PF2 vs DC1 y DC2 (p < 0,001). En las sesiones con Diacontrol, la diferencia media entre la CP final conseguida y programada fue de 0,01 +- 0,07 mS/cm (intervalo de confianza al 95% -0,03-0,008). Asimismo se apreció una correlación inversa entre los valores de CD media y los de la CP prediálisis (r: -0,42, p < 0,05 en DC1 y r: - 0,65, p < 0,001 en DC2). La TMI fue de 420,73 +- 126,9 mEq en PF1, 311,96 +- 161,75 en DCI, 278,34 +- 153,14 en DC2 y 417,66 +- 152,17 en PF2 (p < 0,001 PF1 y PF2 vs DCI yDC2). Podemos concluir que el sistema «biofeedback» Diacontrol permite programar un valor de conductividad plasmática al final de la sesión de hemodiálisis, en lugar de programar los valores de conductividad en el dializado. Por tanto, permite mantener una CP plasmática y una TMI inferior a aquellas logradas en las sesiones con perfiles descendentes de conductividad en el líquido de diálisis, manteniendo una estabilidad hemodinámica similar

Programmed variable sodium in the dialysate can improve hypotension during hemodialysis but may also alter sodium balance and thus resulting in a increase of water intake and weight gain between dialysis sessions. The aim of this study was to evaluate the changes on plasma volume (PV), Ionic Mass Transfer (IMT) and plasma conductivity (PC) with two different hemodialysis techniques. We studied 10 patients during a four-period protocol (one week each: PF1-DC1 -DC2PF2): 120 dialysis sessions. During periods PF1 and PF2, the dialysis procedure was as usual, with exponential decrease of dialysate conductivity (DC) profile (15.7 mS/cm at start, 14.4 mS/cm at middle and 13.8 mS/cm at the end of the session) and UF profile (1.7 1/h at start and 0.1 1/h at the end). During periods DC1 and DC2, DC was automatically determined by a biofeedback module (DiacontroITM) in order to reach a plasma water conductivity fixed at 14 mS/cm. All hemodialysis parameters were the same for the four periods: duration, blood and dialysate flow rates, dialysis membrane. A lower reduction of PV was evident on PF1 and PF2 (104 +- 3.26% and -4.36 +- 2.7%) compared with DC 1 and DC2 (-6.53 +- 3.31% and -6.67 +- 3.12%) (p 0.001 PF1 and PF2 vs. DC1 and DC2). DiacontrolTM determines automatically an individualized DC profile for each patient, and accurately reaches the prescribed PC target. By reaching both the dry weight and PC settings, the water and sodium pool is mantained lower in the hemodialysis session using a biofeedback module. Clinical tolerance was similar in the two different dialysis procedures