Consequences of incomplete repair of acute type A aortic dissection

Abstract During emergency repair of acute Stanford type A aortic dissections, surgical compromises in the form of incomplete arch replacement are made due to the unstable condition of the patient and safety issues of the performing team. We report a case of delayed reoperation after previous incomplete surgery for acute type A aortic dissection in a young patient with Marfan's syndrome. He presented again with repetitive chest pain five years after initial surgical treatment. Extensive aneurysmal dilatation of the aorta and remaining dissection led to the decision to replace the ascending aorta and the aortic arch. After a good progress during the first days after surgery, the patient died due to a ruptured thoraco-abdominal aneurysm on the fifth postoperative day. Extensive surgical reconstruction including aortic arch replacement should be considered in patients with Marfan's syndrome who present with aortic dissections type A to avoid unnecessary reoperations and their complications

Allopurinol/uricase and ibuprofen enhance engraftment of cardiomyocyte-enriched human embryonic stem cells and improve cardiac function following myocardial injury

Objective: A major limitation of stem cell transfer is early donor-cell death. Here, we seek to enhance myocardial repair following injury through transplantation of cardiomyocyte-enriched human embryonic stem cells (hESC) and recipient treatment with cytoprotective (allopurinol + uricase) and anti-inflammatory (ibuprofen) agents. Methods: We injected 106 (15% hESC-derived cardiomyocytes) green fluorescent protein (GFP+) hESC in the infarcted area following left anterior descending artery (LAD)-ligation in SCID-beige mice. In Group I, 1.6 mg allopurinol and 0.2 mg of uricase were injected i.p. for 3 days prior to cell transplantation. In Group II, 0.35 mg/ml of ibuprofen were added to the drinking water before and after cell implantation. In Group III, the LAD was ligated and allopurinol/uricase was administered without cell treatment. In Group IV, ibuprofen was added to the drinking water and the LAD was ligated without additional cell treatment. In Group V, only cells were transplanted. Group VI involved infarcted controls and Group VII involved sham-operated mice (all groups: n = 5). We evaluated heart function (ejection fraction (EF)) by MRI (4.7 T) 3 weeks later. The hearts were harvested for histology. Results: Differentiated hESC formed clusters and expressed α-sarcomeric actin and Connexin 43. Cell treatment improved heart function, which was best in the ibuprofen- and allopurinol-treated groups (+cell transfer), compared to the infarcted controls [EF: Group I: 76.6 ± 8.6%, Group II: 78.6 ± 7.3%, Group III: 58.1 ± 5.7%, Group IV: 53.9 ± 5.2%, Group V: 57.7 ± 7.5%, Group VI: 43.5 ± 4.3%, and Group VII: 66.3 ± 7.8%]. We did not observe tumors in any group. Conclusions: Allopurinol/uricase and ibuprofen enhance differentiated hESC-engraftment and myocardial restoration following transplantation into the injured heart. © 2005 Elsevier B.V. All rights reserved

Symplasmic phloem unloading and radial post-phloem transport via vascular rays in tuberous roots of Manihot esculenta

Cassava (Manihot esculenta) is one of the most important staple food crops worldwide. Its starchy tuberous roots supply over 800 million people with carbohydrates. Yet, surprisingly little is known about the processes involved in filling of those vital storage organs. A better understanding of cassava carbohydrate allocation and starch storage is key to improving storage root yield. Here, we studied cassava morphology and phloem sap flow from source to sink using transgenic pAtSUC2::GFP plants, the phloem tracers esculin and 5(6)-carboxyfluorescein diacetate, as well as several staining techniques. We show that cassava performs apoplasmic phloem loading in source leaves and symplasmic unloading into phloem parenchyma cells of tuberous roots. We demonstrate that vascular rays play an important role in radial transport from the phloem to xylem parenchyma cells in tuberous roots. Furthermore, enzymatic and proteomic measurements of storage root tissues confirmed high abundance and activity of enzymes involved in the sucrose synthase-mediated pathway and indicated that starch is stored most efficiently in the outer xylem layers of tuberous roots. Our findings form the basis for biotechnological approaches aimed at improved phloem loading and enhanced carbohydrate allocation and storage in order to increase tuberous root yield of cassava