Characteristics and comparisons of acute stroke in “recovered" to “active COVID-19 and “pre-pandemic” in Qatar database

Journal of Thrombosis and Thrombolysis - Understanding the relationship of COVID-19 to stroke is important. We compare characteristics of pre-pandemic stroke (PPS), cases in acute COVID infection...     

Contrast-enhanced 64-section coronary multidetector CT angiography versus conventional coronary angiography for stent assessment

PURPOSE: To prospectively evaluate the accuracy of 64-section computed tomography (CT) for diagnosis of stent restenosis, by using conventional coronary angiography as the reference standard. MATERIALS AND METHODS: The ethics committee granted permission for the study; patients gave written consent. Contrast material-enhanced coronary CT angiography was performed in 53 patients (45 men, eight women; mean age, 54 years +/- 9 [standard deviation]) suspected of having stent restenosis. Coronary CT angiographic findings were compared with conventional coronary angiographic findings. Two physicians analyzed coronary CT angiographic data sets with multiplanar reformatted images and three-dimensional reformations by using a volume-rendering technique and looked for stent detectability, low-attenuation in-stent filling defects, and grades of restenosis. Conventional coronary angiographic results were interpreted by one of several observers in consensus for stent restenosis; they were blinded to coronary CT angiographic data. Statistical software and general estimating equations were used for data analysis. RESULTS: One hundred ten stents were identified in 53 patients. Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of coronary CT angiography in detection of in-stent restenosis were 96.9%, 88.0%, 77.5%, 98.5%, and 91%, respectively. Coronary CT angiography depicted in-stent low-attenuation filling defects with an accuracy of 91% and negative predictive value of 98.5% (95% confidence interval: 90.9, 99.9). Coronary CT angiography depicted the status of 97 of 107 stents. There was no significant difference between in-stent lumen visibility and stent diameter (P = .104). Coronary CT angiography helped diagnose 15 of 18 stent restenoses with less than 50% narrowing, five of five stent restenoses with 50%-74% narrowing, and nine of nine (100%) stent restenoses with 75% or greater narrowing or total occlusion of the stent lumen. CONCLUSION: Coronary CT angiography can depict in-stent low-attenuation filling defects, which appear to be a reliable sign of stent restenosis, and 64-section CT depicts such defects with a high degree of accuracy.     

A review on convenient synthesis of substituted coumarins using reuseable solid acid catalysts

Due to growing concern about chemicals and their impact on the environment, cleaner reaction conditions are needed to be incorporated into chemical synthetic procedures. Recently, the use of heteropolyacid catalysts, mainly reuseable solid acid catalysts, has gained a leading role in organic synthesis due to their environmental and economic considerations and industrial utilization. The high catalytic activity, moisture sensitivity, reusability and inexpensive makes solid supported reagents attractive substituents to conventional Lewis acids. Nowadays synthesis of coumarins and their derivatives has attracted considerable attention from organic and medicinal chemists for many years as a large number of natural products contain this heterocyclic nucleus. In continuation with our investigations into the synthesis of substituted coumarins and due to several advantages of heterogeneous catalysts viz. cost-effective, no side products, high yield of desired products and no toxic waste material, here we report a new approach for the synthesis of substituted coumarins using solid acid catalysts.

Due to growing concern about chemicals and their impact on the environment, cleaner reaction conditions are needed to be incorporated into chemical synthetic procedures.     

Deletion of chromosome 11p15, p12, q22, q23-24 loci in human prostate cancer

Loss of heterozygosity (LOH) on chromosome 11 is frequently altered in various epithelial cancers. The present study was designed to investigate LOH on chromosome 11 in microdissected samples of normal prostatic epithelium and invasive carcinoma from the same patients. For this purpose, DNA was extracted from the microdissected normal and tumor cells of 38 prostate cancers, amplified by polymerase chain reaction PCR and analyzed for LOH on chromosome 11 using 9 different polymorphic DNA markers (D11S1307, D11S989, D11S1313, D11S898, D11S940, D11S1818, D11S924, D11S1336 and D11S912). LOH on chromosome 11 was identified in 30 of 38 cases (78%) with at least one marker. Four distinct regions of loss detected were: 1) at 11p15, at loci between D11S1307 and D11S989; 2) at 11p12, on locus D11S131 (11p12); 3) at 11q22, on loci D11S898, D11S940 and D11S1818; and 4) at 11q23-24, on loci between D11S1336 and D11S912. We found 25% of the tumors with LOH at 11p15; 39% had LOH at 11p12; 66% had LOH at 11q22; and 47% had LOH at 11q23-24. These deletions at 11p15, 11p12, 11q22 and 11q23-24 loci were not related to the stage or grade of the tumor. Int. J. Cancer 72:283–288, 1997. © 1997 Wiley-Liss, Inc.     

Ross procedure in rheumatic aortic valve disease.

OBJECTIVE: To assess the results of aortic valve replacement with the pulmonary autograft in patients with rheumatic heart disease. METHODS: From October 1993 through September 2003, 81 rheumatic patients with aortic valve disease, mean age 29.5+/-11.9 years (11-56 years) underwent, the Ross procedure with root replacement technique. Forty patients were 30 years of age or below (young rheumatics). Associated procedures included mitral valve repair (n=19), open mitral commissurotomy (n=15), tricuspid valve repair (n=2), and homograft mitral valve replacement (n=2). RESULTS: Early mortality was 7.4% (six patients). Mean follow-up was 92.3+/-40.9 months (7-132 months, median 109 months). Sixty of the 73 patients whose follow-up was available (82%) had no significant aortic regurgitation. Re-operation was required in seven (8.4%) patients for autograft dysfunction with failed mitral valve repair (n=3), autograft dysfunction alone (n=2) and failed mitral valve repair alone (n=2). No re-operations were required for the pulmonary homograft. There were six (7.5%) late deaths. Actuarial survival and re-operation-free survival at 109 months were 84.5+/-4.1% and 90.5+/-3.7%, respectively. Freedom from significant aortic stenosis or regurgitation was 78.4+/-5.2% and event-free survival was 64.6+/-5.8%. When compared to rheumatics above 30 years of age, the relative risk of autograft dysfunction was high in the young rheumatics. CONCLUSION: The Ross procedure is not suitable for young patients with rheumatic heart disease. However, it provides acceptable mid-term results in carefully selected older (>30 years) patients with isolated rheumatic aortic valve disease.