Our study is the first to suggest that enhanced postoperative left ventricular mass regression, specifically in patients undergoing aortic valve replacement for aortic stenosis, may be associated with improved long-term survival. In view of these findings, strategies purported to be associated with superior left ventricular mass regression should be considered when undertaking aortic valve replacement.

The reduction of methylene green (MG) into protonated leuco dye with ethylenediamine tetraacetic acid (EDTA) in aqueous alkaline medium was studied spectrophotometrically at λ max 660 nm. EDTA behaved as an effective electron donor during the reduction of MG in an aerobic condition. Consumption of EDTA in the reduction of MG means that it is oxidized. This is an unexpected result since EDTA does not normally function as a reducing agent. The nitrogen-containing chelating agents with secondary or tertiary nitrogen behaved as an electron donor in photochemical reaction of dye. The rate of reduction depends upon pH in the same way as the base titration of EDTA. Effects of salt and temperature have been investigated for the reduction process. The salting agent KNO 3 has been found to uniquely enhance the rate of reduction of MG by EDTA in the aerobic condition. Detailed kinetic and thermodynamic aspects have been discussed to realize the interaction between MG and EDTA. Kinetic studies revealed that reaction was sensitive and regeneration of oxidized form of the dye was observed. Reversible first order reaction kinetics with respect to EDTA, MG and NaOH was found.

The xenograft stentless valve was designed to emulate the haemodynamic performance of the allograft. Early outcomes using either surgical option (stentless xenograft valve or allograft) have been similar. However, follow-up outcomes remain to be compared. Between 1st January 1991 and 1st January 2001, 415 patients underwent aortic valve replacement. Two hundred and seventeen patients received an allograft and in 198 patients a Toronto stentless porcine valve (TSPV) was implanted. Mean time to follow-up was 6.3+/-4.4 years. Ten years freedom from structural valve deterioration (SVD) (TSPV 86+/-5%, allograft 82+/-5%, P=0.49) and freedom from reoperation (RE) (TSPV 80+/-4% vs. allograft 85+/-4%, P=0.61) were not significantly different. The TSPV was associated with significantly worse actuarial survival than the homograft (TSPV 40+/-4% vs. homograft 55+/-4%, P=0.02). However, after adjustment for other variables using a multivariate model, TSPV use was not an independent predictor of impaired late survival (LS) (P=0.44). Kaplan-Meier analysis in a subgroup of patients aged 45-65 years comparing LS, RE and SVD between xenografts and allografts identified similar results. The porcine stentless valve may be associated with similar clinical performance to the allograft over the medium to long-term.

Both the subcoronary and root replacement techniques for homograft aortic valve replacement are associated with excellent midterm survival and clinical performance. Root replacement was associated with an increased risk of perioperative death after adjustment for covariates by using propensity analysis.

BackgroundPeripheral neuropathy is a controversial but serious complication of beta-thalassemia (β-Th). Although few studies have reported no relationship between neuropathy and thalassemia, many have linked it with increasing age, iron overload, and iron chelator toxicity. This study aims to investigate the presence of neuropathy in β-Th using corneal nerve fibers. MethodologyA cross-sectional study was conducted using corneal confocal microscopy on individuals with intermediate and major β-Th who were compared to healthy individuals. The main outcome variables were corneal main nerve and branch nerve densities which were calculated using Image J software. The comparison between groups was done using the independent-samples F-test and Bonferroni post-hoc analysis. ResultsThere was reduced corneal main nerve and branch nerve density in β-Th intermediate and major patients compared to the control group, and the results were statistically significant (p-value <0.05). However, a significant correlation was not observed between serum ferritin levels and corneal nerve parameters. ConclusionsThe reduction in corneal nerve parameters in β-Th patients compared to healthy controls can be an indication of peripheral neuropathy in β-Th. Further work is needed to confirm these findings.