Chloride-binders and their effect on the physico-mechanical properties of sulfate-resisting cement (SRC) hardened pastes upon exposure to sea water attack.

In Egypt, the national strategic plan for population redistribution supports the establishment of new towns and urban settlements across the coastal zones to relieve the pressure on the packed Nile Valley and Delta and encourages internal migration to new urban coastal communities. Since reinforced concrete has a poor service record in these areas, this situation urged us to design a research program in which a new route has been followed for confronting the concomitant effect of sulfate and chloride attack. Therefore, sulfate-resisting cement (type V) has been used for preparing concrete. The cement has been blended with a chloride-binder for fixing free chloride into an insoluble (or poorly soluble) reaction product. As to the steel reinforcement, the research program will investigate steel protection by an innovative inhibited cement slurry coating. The current-first part-of the research program has been concentrated for determining the influence of a chloride-binder [lead oxide (PbO)] as well as a novel proposed chemical compound [lead nitrate: Pb(NO3)2], as chloride-binders, on the physico-mechanical properties of hardened SRC pastes upon exposure to sea water. The investigation disclosed that these compounds marginally delay the setting time relative to the chloride-binder-free pastes, yet they improve workability, maintain alkalinity (hence carbonation resistance), and yield better compressive strength.

Double-balloon valvuloplasty of calcified bioprosthetic pulmonary valve twenty-three years after implantation.

Balloon valvuloplasty to dilate stenotic bioprosthetic valves is rarely used, but has been applied successfully to dilate bioprosthetic mitral, aortic, tricuspid and, to a lesser extent, pulmonary valves. The case is reported of a 45-year-old male patient with right-sided heart failure who underwent a successful dilatation of a stenotic, calcific bioprosthetic pulmonary valve using double-balloon valvuloplasty.

Giant left atrium associated with massive thrombus formation.

Giant left atrium is a condition characterized by huge enlargement of the left atrium with a diameter exceeding 65mm. It is most commonly associated with long standing rheumatic mitral valve disease. We present a 45-year-old female patient with rheumatic mitral stenosis associated with giant left atrium occupied by an 11 × 10 × 5 cm thrombus weighing 500 gms. The patient underwent successful mitral valve replacement and thrombectomy through an inverted T-shaped biatrial incision.

Percutaneous mitral valvotomy versus closed surgical commissurotomy. Up to 15 years of follow-up of a prospective randomized study.

BACKGROUND: Immediate and intermediate term results of percutaneous mitral valvotomy (PMV) are comparable to closed surgical commissurotomy (CSC). We aimed at exploring this relation in the long term. METHODS: Previously, we randomized 40 consecutive patients with moderate to severe mitral stenosis [defined as mitral valve area (MVA) less than 1.5 cm²] to undergo either PMV (PMV group = 20 patients) or CSC (CSC group = 20 patients). For all patients, full echocardiographic assessment was performed before the procedure/operation. Patients assigned to PMV underwent the double balloon technique. Echocardiographic assessment was done following both procedures before discharge and repeated 1 and 6 months later. Echocardiographic follow-up was performed, thereafter, on a yearly basis for up to 15 years, with a mean follow-up period of 99 ± 12 months. RESULTS: Immediate echocardiographic results showed no statistically significant difference between the 2 groups regarding the final MVA or mean diastolic gradient across the mitral valve. Two patients dropped out from the CSC group and one from the PMV group. MVA was 1.8 ± 0.3 cm² versus 1.8 ± 0.4 cm² (p > 0.05) and mean diastolic pressure gradient across the mitral valve was 7 ± 4 mmHg versus 6.6 ± 4 mmHg (p > 0.05) in the PMV and CSC groups, respectively. Mitral restenosis occurred in 5 (26.3%) patients in the PMV group versus 5 (27.8%) patients in the CSC group (p > 0.05). Kaplan-Meier curves for restenosis-free survival showed no difference between the 2 groups. CONCLUSION: PMV achieves comparable results to CSC both in the short and long term.