Biomedical subjects
Publications and source records attributed to E Mahmud.
We describe a case of a coronary artery perforation involving the proximal right coronary artery that was successfully managed by percutaneous coil embolization. In the setting of a chronic coronary artery occlusion, this demonstrates the successful use of thrombogenic platinum alloy coils for a large proximal vessel perforation which has not been described previously.
BACKGROUND: Although rarely seen in healthy patients, the coronary sinus (CS) is often visualized on echocardiography in patients with right-sided heart disease. However, the prevalence of this finding and its relation to right-sided heart structure and pressure remains undefined. METHODS: We examined the transthoracic echocardiograms of 43 consecutive patients referred for the evaluation of pulmonary hypertension (26 men, 17 women) with a mean age of 53 +/- 15 years (range 21 to 82 years). Structural abnormalities of the tricuspid valve were absent. All patients underwent right heart catheterization within 48 hours of their echocardiogram, which revealed the following pressures: mean pulmonary artery (50 mm Hg, range 31 to 84 mm Hg) and right atrial (RA) (mean 10, range 1 to 24 mm Hg). Echocardiograms were analyzed for CS size (identified as the smallest diameter of a circular structure in the left atrioventricular groove in the parasternal long-axis view), as well as RA and right ventricular (RV) sizes. The presence and severity (grades 1 through 3) of tricuspid regurgitation (TR) were also recorded. RESULTS: The CS was visualized in 35 (81%) of 43 patients, and measurements ranged from 0.4 to 1.6 cm (mean 0.8 cm). No difference in RA size, RV size, TR grade, RA pressure (RAP), RV pressure (RVP), mean pulmonary artery pressure (PAP), or pulmonary vascular resistance (PVR) was observed between patients with a visualized and nonvisualized CS. Coronary sinus size correlated significantly with RA size (r = 0.60, P <.001) and pressure (r = 0.59, P <.001), but not with RV size, degree of TR, RVP, PAP, or PVR. Nineteen of 35 patients with a visualized CS underwent pulmonary artery thromboendarterectomy (PTE), and their CS size and RAP were unchanged (0.8 cm and 12 mm Hg, respectively, preand post-PTE; both P = NS [not significant]), though a decrease was observed in other measurements: RA size (4.2 versus 4.8 cm, P =.02), RV size (4.2 versus 5.1 cm, P =.0004), mean PAP (37 versus 72 mm Hg, P <.0001), and PVR (230 versus 899 mm Hg, P <.0001). CONCLUSIONS: Coronary sinus dilation was observed in 81% of a selected group of patients with pulmonary hypertension in the absence of structural disease of the tricuspid valve. Coronary sinus dilation is related to RAP and RA size, but not to RV size, degree of TR, RVP, PA pressure, or PVR. Once dilated, CS size does not change shortly after decreases of RA size, RV size, or PA pressure produced by PTE.
Gastrulating chick embryos in culture were treated with ethanol solutions, following which the mesoderm cells migrating from the primitive streak were examined by scanning electron microscopy. Morphometric analysis of cell shape showed that mesoderm cells from treated embryos were significantly more rounded and therefore less well spread than controls, and showed fewer filopodial contacts with the overlying basement membrane. This result was only obtainable for cells leading the migration from the primitive streak, since the following cells in the mesodermal mass apparently did not show this difference. The ethanol concentration required to obtain a reliable effect was 5%, while lower concentrations produced highly variable results. The mesoderm cells were also examined for their in vitro responsiveness to ethanol by investigating their adhesiveness and cytoskeleton. No effect was observed on cell-glass adhesion as judged by interference reflection microscopy using up to 1% ethanol. This concentration did, however, disrupt the actin cytoskeleton of cultured cells when stained with NBD-phallacidin, but lower concentrations were ineffective. It is concluded that ethanol treatment of cultured embryos has a significant effect on the substratum relationships of some migrating mesoderm cells.
Explore the source record for details and available documents.