185 research outputs found

    Selectra 3D- guided conduction system pacing: single-center experience

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    Abstract Background Conduction system pacing (CSP)is becoming increasingly popular thanks to the ability to both maintain physiological electrical activation in patients with narrow QRS and restore ventricular synchrony in patients with bundle branch block (BBB). The Selectra3D introducer is a new tool able to support the correct positioning and screwing of the catheter on the bundle of His (HBP) or on the left branch (LBBP). It does exist in 3 different shapes: S, M, L (Fig. 1) based on the radius of main curvature. The internal diameter of 7.3 Fr allows it to support both the 3830 lumen-less catheter historically used for CSP, as well as standard 6Fr stylet-driven leads. Objective To evaluate the effectiveness of the Selectra3D introducer for CSP (including both HBP and LBBP), considering the procedural success rate and the lead stability (stability of electrical parameters or need for implant revision) in the medium-term follow-up. Methods and results The Selectra3D introducer was used in 56 patients' candidates for CSP (mean age 80±6 years). Pacing indications included A-V block in 21 patients, AF with slow ventricular response in 9 patients; SND in 8 patients and HF and severe ventricular dysfunction in 18 patients (of which 4 were PICM). The mean baseline EF was 40±15%. A PM was implanted in 40 patients and an ICD in 16. A standard stylet-driven lead was used in 48 cases, a fixed exposed screw lead was used in 8 patients. HBP was obtained in 21 cases and LBBP in 30 cases, while in 5 cases (8.9%) neither HBP nor LBBP could be obtained. Implants were performed via a left-sided approach in 55 cases and a right-sided approach in 1 case. The baseline QRS duration was 144±38 ms and the paced QRS duration was 118±21 ms. The electrical parameters were optimal with sensing 8.7±8 mV; impedance 625±276 ohm; threshold 1±0.5 V. During follow-up, 2 lead dislodgement (3.9%) (1 HBP and 1 LBBP) were recorded, both within 7 days after implantation. All the others showed stability of the electrical parameters at a mean follow-up of 8.4±4.2 months. Conclusions The new Selectra3D introducer supports effectively and safely the lead implant on conduction system catheters (HBP and LBBP), allowing the implant of both exposed fixed screw leads and standard stylet-driven leads, leading to procedural success>90%. The electrical parameters were optimal at implantation and remained stable during follow-up. Funding Acknowledgement Type of funding sources: None. Figure

    Long-Term Oral Administration of Theaphenon-E Improves Cardiomyocyte Mechanics and Calcium Dynamics by Affecting Phospholamban Phosphorylation and ATP Production

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    Background/Aims: Dietary polyphenols from green tea have been shown to possess cardio-protective activities in different experimental models of heart diseases and age-related ventricular dysfunction. The present study was aimed at evaluating whether long term in vivo administration of green tea extracts (GTE), can exert positive effects on the normal heart, with focus on the underlying mechanisms. Methods: The study population consisted of 20 male adult Wistar rats. Ten animals were given 40 mL/day tap water solution of GTE (concentration 0.3%) for 4 weeks (GTE group). The same volume of water was administered to the 10 remaining control rats (CTRL). Then, in vivo and ex vivo measurements of cardiac function were performed in the same animal, at the organ (hemodynamics) and cellular (cardiomyocyte mechanical properties and intracellular calcium dynamics) levels. On cardiomyocytes and myocardial tissue samples collected from the same in vivo studied animals, we evaluated: (1) the intracellular content of ATP, (2) the endogenous mitochondrial respiration, (3) the expression levels of the Sarcoplasmic Reticulum Ca2+-dependent ATPase 2a (SERCA2), the Phospholamban (PLB) and the phosphorylated form of PLB, the L-type Ca2+ channel, the Na+-Ca2+ exchanger, and the ryanodine receptor 2. Results: GTE cardiomyocytes exhibited a hyperdynamic contractility compared with CTRL (the rate of shortening and re-lengthening, the fraction of shortening, the amplitude of calcium transient, and the rate of cytosolic calcium removal were significantly increased). A faster isovolumic relaxation was also observed at the organ level. Consistent with functional data, we measured a significant increase in the intracellular ATP content supported by enhanced endogenous mitochondrial respiration in GTE cardiomyocytes, as well as higher values of the ratios phosphorylated-PLB/PLB and SERCA2/PLB. Conclusions: Long-term in vivo administration of GTE improves cell mechanical properties and intracellular calcium dynamics in normal cardiomyocytes, by increasing energy availability and removing the inhibitory effect of PLB on SERCA2

    Is supercomplex organization of the respiratory chain required for optimal electron transfer activity?

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    AbstractThe supra-molecular assembly of the main respiratory chain enzymatic complexes in the form of “supercomplexes” has been proved by structural and functional experimental evidence. This evidence strongly contrasts the previously accepted Random Diffusion Model stating that the complexes are functionally connected by lateral diffusion of small redox molecules (i.e. Coenzyme Q and cytochrome c).This review critically examines the available evidence and provides an analysis of the functional consequences of the intermolecular association of the respiratory complexes pointing out the role of Coenzyme Q and of cytochrome c as channeled or as freely diffusing intermediates in the electron transfer activity of their partner enzymes

    Outcomes of structural fat grafting for paralytic and non-paralytic dysphonia=Risultati della lipostruttura nel trattamento della disfonia paralitica e non paralitica

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    Aims of this prospective study were to evaluate the results of vocal fold structural fat grafting for glottic insufficiency and to compare the outcomes obtained in unilateral vocal fold paralysis (UVFP) and congenital or acquired soft tissue defects in vocal folds. Sixty-six consecutive patients with breathy dysphonia, in 43 cases (aged 16-79 years) related to UVFP and in 23 cases (aged 16-67 years) related to vocal fold iatrogenic scar or sulcus vocalis, underwent autologous structural fat grafting into vocal folds. Lipoaspirates were centrifuged at 1200 g for 3 min to separate and remove blood, cell debris and the oily layer. The refined fat was injected under direct microlaryngoscopy in a multilayered way. The main outcome measures were grade, roughness, breathiness, asthenicity and strain (GRBAS) perceptual evaluation, maximum phonation time (MPT), self-assessed Voice Handicap Index (VHI), and voice acoustic analysis, considered pre-operatively and at 3 and 6 months after fat grafting. After surgery, MPT, VHI, G and B improved in both groups (p < 0.05). In particular, G and VHI functional subscales showed a significantly greater decrease in patients with UVFP (p < 0.05). The acoustic variables improved significantly only in the UVFP group (p < 0.005). From 3 to 6 months postoperatively, most variables showed a trend with further improvement. Vocal fold structural fat grafting was significantly effective in treating glottic insufficiency due to UVFP or soft tissue defects. Perceptual, acoustic and subjective assessments confirmed that patients with UVFP had better outcomes than those with soft tissue defects

    Prevalence of thoracic vertebral fractures in hospitalized elderly patients with heart failure

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    ObjectiveHeart failure (HF) has been associated with increased risk of fragility fractures. Indeed, most literature data on fractures were based on an historical and clinical approach focused on the identification of peripheral fractures, whereas the risk of vertebral fractures in this clinical setting is still unclear.DesignCross-sectional study.AimTo evaluate the prevalence and determinants of radiological thoracic vertebral fractures in patients with HF.MethodsThe study includes 1031 elderly hospitalized patients (491 females and 540 males; median age, 75 years; range, 65–90; 430 patients with HF) who were evaluated for the presence of thoracic vertebral fractures by quantitative morphometric analysis, using chest X-ray routinely performed in the diagnostic work-up of HF.ResultsVertebral fractures were found in 166 patients (16.1%), the prevalence being significantly higher in patients with HF as compared with those without HF, both in females (30.9 vs 15.8%; P<0.001) and in males (16.4 vs 7.4%; P=0.001). The association between HF and vertebral fractures remained statistically significant (odds ratio, 2.14; 95% CI, 1.25–3.66; P=0.01) even after adjustment for age, sex, loop diuretic therapy, anticoagulant therapy, proton pump therapy, coexistent chronic obstructive pulmonary disease, diabetes mellitus, renal insufficiency, and chronic liver diseases. In patients with HF, vertebral fractures were positively correlated with female sex, duration of HF, ischemic heart disease, cigarette smoking, and treatment with anti-osteoporotic drugs, and inversely correlated with left ventricular ejection fraction.ConclusionsHospitalized patients suffering from HF are at higher risk of vertebral fractures than patients without HF in the same clinical context

    The Mixed Vector Current Correlator <0|T(V^3_\mu V^8_\nu )|0> To Two Loops in Chiral Perturbation Theory

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    The isospin-breaking correlator of the product of flavor octet vector currents, VΌ3V^3_\mu and VΜ8V^8_\nu, ΠΌΜ38(q2)\Pi^{38}_{\mu\nu}(q^2) is computed to next-to-next- to-leading (two-loop) order in Chiral Perturbation Theory. Large corrections to both the magnitude and q2q^2-dependence of the one-loop result are found, and the reasons for the slow convergence of the chiral series for the correlator given. The two-loop expression involves a single O(q6){\cal O}(q^6) counterterm, present also in the two-loop expressions for ΠΌΜ33(q2)\Pi^{33}_{\mu\nu}(q^2) and ΠΌΜ88(q2)\Pi^{88}_{\mu\nu}(q^2), which counterterm contributes a constant to the scalar correlator Π38(q2)\Pi^{38}(q^2). The feasibility of extracting the value of this counterterm from other sources is discussed. Analysis of the slope of the correlator with respect to q2q^2 using QCD sum rules is shown to suggest that, even to two-loop order, the chiral series for the correlator may not yet be well-converged.Comment: 32 pages, uses REVTEX and epsfig.sty with 7 uuencoded figures. Entire manuscript available as a ps file at http://www.physics.adelaide.edu.au/theory/home.html Also available via anonymous ftp at ftp://adelphi.adelaide.edu.au/pub/theory/ADP-95-27.T181.p

    The ATPase Inhibitory Factor 1 (IF1) regulates the expression of the mitochondrial Ca2+ uniporter (MCU) via the AMPK/CREB pathway

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    ‱IF1 regulates MCU-dependent mitochondrial Ca2+ uptake. ‱IF1 loss induces MCU upregulation through activation of the AMPK/CREB pathway. ‱OMA1 depletion restores physiological MCU levels and mitochondrial Ca2+ entry

    The use of wind pumps for greenhouse microirrigation: a case study for tomato in Cuba.

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    Crop irrigation is a major consumer of energy. Only a few countries are self-sufficient in conventional non-renewable energy sources. Fortunately, there are renewable ones, such as wind, which has experienced recent developments in the area of power generation. Wind pumps can play a vital role in irrigation projects in remote farms. A methodology based on daily estimation balance between water needs and water availability was used to evaluate the feasibility of the most economic windmill irrigation system. For this purpose, several factors were included: three-hourly wind velocity (W3 h, m/s), flow supplied by the wind pump as a function of the elevation height (H, m) and daily greenhouse evapotranspiration as a function of crop planting date. Monthly volumes of water required for irrigation (Dr, m3/ha) and in the water tank (Vd, m3), as well as the monthly irrigable area (Ar, ha), were estimated by cumulative deficit water budgeting taking in account these factors. An example is given illustrating the use of this methodology on tomato crop (Lycopersicon esculentum Mill.) under greenhouse at Ciego de Ávila, Cuba. In this case two different W3 h series (average and low wind year), three different H values and five tomato crop planting dates were considered. The results show that the optimum period of wind-pump driven irrigation is with crop plating in November, recommending a 5 m3 volume tank for cultivated areas around 0.2 ha when using wind pumps operating at 15 m of height elevation
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