Impact of reductive tricuspid ring annuloplasty on right ventricular size,geometry and strain in an ovine model of functional tricuspid regurgitation

Open in a separate window OBJECTIVESReductive ring annuloplasty of the tricuspid annulus represents the contemporary surgical approach to functional tricuspid regurgitation (FTR). We set out to investigate the influence of moderate reductive tricuspid ring annuloplasty on tricuspid regurgitation and right ventricular (RV) size, geometry and strain in an ovine model of chronic FTR.METHODSEight healthy Dorsett male sheep (62.8 + 2kg) underwent a left thoracotomy for placement and tightening of pulmonary artery band to at least double proximal pulmonary artery blood pressure. After 8 weeks of recovery, animals underwent sternotomy, epicardial echocardiography and sonomicrometry crystal implantation. Six crystals were placed around tricuspid annulus and 13 on RV free wall epicardium along 3 parallels defining 3 wall regions (basal, mid and lower) and 1 on the RV apex. All animals underwent beating heart implantation of 26 mm MC3 annuloplasty ring during a second cardiopulmonary bypass run after baseline data acquisition. Simultaneous haemodynamic, sonomicrometry and echocardiography data were acquired at Baseline and after reductive tricuspid ring annuloplasty.RESULTSImplantation of reductive ring annuloplasty resulted in 47 ± 7% annular area reduction (996 ± 152 mm vs 516 ± 52 mm², P = 0.0002) and significantly decreased RV end-diastolic volume (185 ± 27 vs 165 ± 30 ml, P = 0.02). Tricuspid ring annuloplasty effectively reduced FTR grade (3.75 ± 0.6 vs 0.3 ± 0.5, P = 0.00004) and had little influence on RV function, cross-sectional area, radius of curvature or free wall regional strains.CONCLUSIONSIn adult sheep with 8 weeks of pulmonary artery banding and FTR, tricuspid annulus reduction of 47% with prosthetic ring annuloplasty effectively abolished FTR while maintaining regional RV function and strain patterns.     

Interatomic Potential for InP

Classical modeling of structural phenomena occurring in InP crystal, for example plastic deformation caused by contact force, requires an interatomic interaction potential that correctly describes not only the elastic properties of indium phosphide but also the pressure-induced reversible phase transition B3↔B1. In this article, a new parametrization of the analytical bond-order potential has been developed for InP. The potential reproduces fundamental physical properties (lattice parameters, cohesive energy, stiffness coefficients) of the B3 and B1 phases in good agreement with first-principles calculations. The proposed interaction model describes the reversibility of the pressure-induced B3↔B1 phase transition as well as the formation of native point defects in the B3 phase.     

The efficacy of the use of IR laser phototherapy (LPT) on bone defect grafted with biphasic ceramic on rats with iron deficiency anemia: Raman spectroscopy analysis

The aim of this study was to evaluate bone repair in anemic and non-anemic rats submitted or not to laser phototherapy and hydroxyapatite graft. Animals were divided in eight groups of five animals: Clot; Laser; Graft; Graft + Laser; iron deficiency anemia (IDA) + Clot; IDA + Laser; IDA + graft; IDA + graft + Laser. When appropriate irradiation with infrared laser was done during 15 days at a 48-h interval. Animals were killed at day 30; samples were analyzed by Raman spectroscopy. Three shifts were studied and statistically analyzed: ~960, ~1,070, and ~1,454 cm^?1. Graft + laser showed highest ~960 peak was statistically different from all other healthy groups. No statistical difference was found between Clot and IDA + Clot in any shift. The IDA + Graft and IDA + Graft + Laser groups had low mean peak values for shifts ~960, ~1,070, and ~1,454 cm^?1. The results in this study indicate that using hydroxyapatite (HA) and laser irradiation in healthy subjects is favorable to mineral deposition and bone maturation, this being of importance for some groups at risk, such as astronauts. In iron deficiency anemia cases, the use of graft, associated or not to laser irradiation, resulted in low collagen and low carbonate and phosphate HA.     

Monitoring the Quality of HIV-1 Viral Load Testing through a Proficiency Testing Program Using Dried Tube Specimens in Resource-Limited Settings

HIV-1 viral load (VL) levels are used for monitoring disease progression and antiretroviral therapy outcomes in HIV-infected patients. To assess the performance of laboratories conducting HIV-1 VL testing in resource-limited settings, the U.S. Centers for Disease Control and Prevention implemented a voluntary, free-of-charge, external quality assurance program using dried tube specimens (DTSs). Between 2010 and 2012, DTS proficiency testing (PT) panels consisting of 5 specimens were distributed at ambient temperature to participants. The results from the participants (n ≥ 6) using the same assay were grouped, analyzed, and graded as acceptable within a group mean ± 3 standard deviations. Mean proficiency scores were calculated by dividing the combined PT scores by the number of testing cycles using a linear regression model. Between 2010 and 2012, the number of participants enrolled increased from 32 in 16 countries to 114 in 44 countries. A total of 78.2% of the participants reported results using 10 different VL assays. The rates of reporting of acceptable results by the participants were 96.6% for the Abbott assay, 96.3% for the Roche Cobas assay, 94.5% for the Roche Amplicor assay, 93.0% for the Biocentric assay, and 89.3% for the NucliSens assay. The overall mean proficiency scores improved over time (P = 0.024). DTSs are a good alternative specimen type to plasma specimens for VL PT programs, as they do not require cold chain transportation and can be used on PCR-based assays. Our data suggest that the CDC HIV-1 VL PT program using DTSs positively impacts the testing performance of the participants, which might translate into better and more accurate VL testing services for patients.