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Hybrid operations to treat aortic arch disease can be performed with results comparable to open surgery. The longer-term outcomes demonstrate low rates of reintervention and high rates of graft patency.

The characteristics and prognosis of patients with cystic medial necrosis of the aorta were reviewed. Subjects were 46 patients who underwent aortic and/or aortic valve surgery between August 1965 and October 1994. All had histologically documented cystic medial necrosis including 22 Marfan patients. The patients with Marfan syndrome were substantially younger (median age, 32 vs 50 years; p < 0.05), and experienced annulo-aortic ectasia more frequently {81% (17/22) vs 46% (11/24); p < 0.05} than those without the syndrome. Sixty-eight percent (15/22) of the Marfan patients and 63% (15/24) of the non-Marfan patients experienced complications with aortic dissection, although not to a significant degree. The hospital mortality rate was 14% (3/22) in the Marfan group and 21% (5/24) in the non-Marfan group, which was also not significant. Of the 38 survivors, developments in the health of 37 were completely followed-up until October 1997. The cardiovascular event-free rate for Marfan patients at 10 years (28%) was lower than that for non-Marfan patients (68%, p = 0.057), whereas the actuarial survival rates at 10 years were nearly equal (72% for the Marfan patients and 74% for the non-Marfan patients). Reoperation was the first cardiovascular event in 77% (10/13) of the Marfan patients and in 14% (1/7) of the non-Marfan patients (p < 0.05). Cardiovascular event was the main cause of late death both for Marfan patients (80%; 4/5) and for non-Marfan patients (86%; 6/7). In conclusion, independent of the presence of Marfan syndrome, careful follow-up is necessary for patients with cystic medial necrosis of the aorta to eliminate serious late complications.

Although proglucagon gene expression and the synthesis of proglucagon encoded peptide hormones could be activated by protein kinase A (PKA) activators such as forskolin/3-isobutyl-1-methylxanthine (IBMX) and cholera toxin, whether the activation is entirely attributed to PKA has not been previously examined. We found that forskolin/IBMX also activate ERK1/2 phosphorylation in intestinal and pancreatic proglucagon-producing cell lines. The MEK inhibitors PD98059 and U0126 were found to repress the expression of proglucagon promoter as well as endogenous proglucagon mRNA in two intestinal proglucagon-producing cell lines and to block the stimulatory effect of forskolin/IBMX on proglucagon mRNA expression. The repressive effect of the PKA-specific inhibitors H-89 and KT-5720, however, was either not observable or much less potent. Forskolin could activate ERK1/2 phosphorylation and proglucagon gene transcription on its own, whereas forskolin plus IBMX are required to effectively activate the PKA pathway in the proglucagon-producing cells. Exchange protein directly activated by cyclic AMP 2 (Epac2, or cAMP-binding guanine nucleotide exchange factor-2) was found to be expressed in gut and pancreatic proglucagon-producing cell lines, whereas the Epac-pathway-specific cAMP analog, 8-pMeOPT-2'O-Me-cAMP, effectively stimulated ERK1/2 phosphorylation as well as proglucagon mRNA expression. We therefore suggest that cAMP at least partially regulates proglucagon gene expression via the Epac-Ras/Rap-Raf-MEK-ERK signaling pathway.

Background Medical students commonly refer to Wikipedia as their preferred online resource for medical information. The quality and readability of articles about common vascular disorders on Wikipedia has not been evaluated or compared against a standard textbook of surgery. Objective The aims of this study were to (1) compare the quality of Wikipedia articles to that of equivalent chapters in a standard undergraduate medical textbook of surgery, (2) identify any errors of omission in either resource, and (3) compare the readability of both resources using validated ease-of-reading and grade-level tools. Methods Using the Medical Council of Canada Objectives for the Qualifying Examination, 8 fundamental topics of vascular surgery were chosen. The articles were found on Wikipedia using Wikipedia’s native search engine. The equivalent chapters were identified in Schwartz Principles of Surgery (ninth edition). Medical learners (n=2) assessed each of the texts on their original platforms to independently evaluate readability, quality, and errors of omission. Readability was evaluated with Flesch Reading Ease scores and 5 grade-level scores (Flesch-Kincaid Grade Level, Gunning Fog Index, Coleman-Liau Index, Simple Measure of Gobbledygook Index, and Automated Readability Index), quality was evaluated using the DISCERN instrument, and errors of omission were evaluated using a standardized scoring system that was designed by the authors. Results Flesch Reading Ease scores suggested that Wikipedia (mean 30.5; SD 8.4) was significantly easier to read (P=.03) than Schwartz (mean 20.2; SD 9.0). The mean grade level (calculated using all grade-level indices) of the Wikipedia articles (mean 14.2; SD 1.3) was significantly different (P=.02) than the mean grade level of Schwartz (mean 15.9; SD 1.4). The quality of the text was also assessed using the DISCERN instrument and suggested that Schwartz (mean 71.4; SD 3.1) had a significantly higher quality (P=.002) compared to that of Wikipedia (mean 52.9; SD 11.4). Finally, the Wikipedia error of omission rate (mean 12.5; SD 6.8) was higher than that of Schwartz (mean 21.3; SD 1.9) indicating that there were significantly fewer errors of omission in the surgical textbook (P=.008). Conclusions Online resources are increasingly easier to access but can vary in quality. Based on this comparison, the authors of this study recommend the use of vascular surgery textbooks as a primary source of learning material because the information within is more consistent in quality and has fewer errors of omission. Wikipedia can be a useful resource for quick reference, particularly because of its ease of reading, but its vascular surgery articles require further development.