Charlie Norwood VA Medical Center

About: Charlie Norwood VA Medical Center is a healthcare organization based out in Augusta, Georgia, United States. It is known for research contribution in the topics: Autophagy & Kidney. The organization has 349 authors who have published 490 publications receiving 16360 citations. The organization is also known as: Augusta VA Medical Center.

Safety and efficacy of local periadventitial delivery of sirolimus for improving hemodialysis graft patency: first human experience with a sirolimus-eluting collagen membrane (Coll-R)

Abstract: Background. Neointimal hyperplasia causes a high rate of hemodialysis synthetic graft failure. Thus, therapies that inhibit neointimal hyperplasia are urgently needed. The Coll-R is a sirolimus-eluting collagen matrix designed for intra-operative perivascular implantation around the graftvenous anastomosis. Sirolimus is an anti-proliferative drug that has proven clinical utility in suppressing neointimal tissue growth in coronary artery disease when delivered locally to the vascular wall by an endovascular drug eluting stent. Methods. A cohort of 12 chronic hemodialysis patients underwent surgical placement of 13 polytetrafluoroethylene grafts 1 Coll-R and were followed for up to 24 months. The primary endpoint was safety (freedom from device related adverse events). Secondary endpoints were pharmacokinetics of sirolimus release, success of Coll-R implantation and primary unassisted graft patency. Results. There were no technical failures, infections, vascular anastomotic or wound-healing problems. Whole blood sirolimus levels rose to a mean peak of 4.8 ng/mL at 6 h and fell to <1 ng/mL at 1 week (n ¼ 5). Twelve and 24-month primary unassisted patencies were 76 and 38%, respectively, and the thrombosis rate was 0.37/patient-year. Conclusions. Perivascular implantation of the Coll-R during graft surgery safely delivered sirolimus to the vascular wall. Systemic sirolimus levels were sub-therapeutic for immunosuppression. This small first-in-human study supports the concept that the Coll-R can safely deliver sirolimus to the graft-venous anastomosis. Safety and patency in this small study were sufficiently encouraging to justify randomized controlled trials to further test the efficacy of the Coll-R.

AT1 Receptor Antagonism Is Proangiogenic in the Brain: BDNF a Novel Mediator

Abstract: Candesartan is an angiotensin II type 1 receptor blocker (ARB) that has been to shown to limit ischemic stroke and improve stroke outcome. In experimental stroke, candesartan induces a proangiogenic effect that is partly attributable to vascular endothelial growth factor. Brain-derived neurotrophic factor (BDNF) is a member of the neurotrophin family that has been reported to have angiogenic effects and play an important role in recovery after stroke. The purpose of this investigation was to determine the role of BDNF in the proangiogenic effect of candesartan in the brain under hypertensive conditions. Accordingly, spontaneously hypertensive rats were treated with candesartan, and brain tissue samples were collected for quantification of BDNF expression. In addition, human cerebromicrovascular endothelial cells were treated with either low-dose (1 ƒM) or high-dose (1 µM) angiotensin II alone or in combination with candesartan (0.16 µM) to assess the effect of candesartan treatment and BDNF involvement in the behavior of endothelial cells. Candesartan significantly increased the expression of BDNF in the SHR (P < 0.05). In addition, candesartan reversed the antiangiogenic effect of the 1-µM dose of AngII (P = 0.0001). The observed effects of candesartan were ablated by neutralizing the effects of BDNF. Treatment with the AT2 antagonist PD-123319 significantly reduced tube-like formation in endothelial cells. AT2 stimulation induced the BDNF expression and migration (P < 0.05). In conclusion, candesartan exerts a proangiogenic effect on brain microvascular endothelial cells treated with angiotensin II. This response is attributable to increased BDNF expression and is mediated through stimulation of the AT2 receptor.

Myeloid neoplasms associated with eosinophilia and rearrangement of PDGFRA, PDGFRB, and FGFR1: a review

Abstract: Summary Myeloid and lymphoid neoplasms with eosinophilia and abnormalities of platelet-derived growth factor receptor alpha (PDGFRA), platelet-derived growth factor receptor beta (PDGFRB), and fibroblast growth factor receptor-1 (FGFR1) are a group of hematologic neoplasms resulting from the formation of abnormal fusion genes that encode constitutively activated tyrosine kinases. These entities are now separated into their own major category in the 2008 World Health Organization classification of hematolymphoid tumors. Although eosinophilia is characteristic of these diseases, the clinical presentation of the three entities is variable. Conventional cytogenetics (karyotyping) will detect the majority of abnormalities involving PDGFRB and FGFR1, but florescence in situ hybridization (FISH)/molecular studies are required to detect factor interacting with PAP (FIP1L1)–PDGFRA as the characteristic 4q12 interstitial deletion is cryptic. Imatinib mesylate (imatinib) is the first-line therapy for patients with abnormalities of PDGFRA/B, whereas patients with FGFR1 fusions are resistant to this therapy and carry a poor prognosis. The discovery of novel gene rearrangements associated with eosinophilia will further guide our understanding of the molecular pathobiology of these diseases and aid in the development of small-molecule inhibitors that inhibit deregulated hematopoiesis.