Vascular Repair (vascular + repair)

Distribution by Scientific Domains

Selected Abstracts


L. C. Teoh
The function of the replanted parts can be improved if attention to reconstruction techniques is carried out. These reconstructive techniques are: 1) adequate debridement and shortening, 2) stable skeletal fixation, 3) strengthened tendon repairs, 4) quality nerve repair, 5) extensive vascular anastomosis, 6) complete skin coverable, and 7) Early intensive active rehabilitation. 1) The debridement should be generous and the shortening judicious. More than 50% of the skin should be in direct contact, and direct anastomosis of some of vessels should be possible. 2) The skeletal stabilization should be of good very quality that will allow free mobilization of the joints. 3) The repair of the tendons should take advantage of the excess length for a strengthen repair. Some degree of active mobilization should be make possible. 4) Primary nerve grafting or nerve transfer should be considered if there is loss of nerve length. 5) Vascular repair should be on the basis of as many as possible the number of arteries and veins that can be found for anastomosis. 6) Any residual skin defect should be planned for a proper resurfacing within the next 5 to 10 days. 7) Early intensive active rehabilitation should be prescribed. Gradual active ROM for tendon gliding should be instituted with in the first week. The function of the replanted digit and hand has continued to improve with the reconstructive approach. With further experience the reconstructive approach can be done in all cases with confidence. [source]

LDL lipid apheresis rapidly increases peripheral endothelial progenitor cell competence

Daniel Patschan
Abstract Background and Aim: Endothelial progenitor cells (EPCs) have been shown to promote neovascularization under physiologic and pathologic conditions. Statins have been documented to increase the total number of circulating EPCs in long-term treated patients. Lipid apheresis is used to treat patient with refractory hyperlipidemia. The aim of our study was to evaluate whether lipid apheresis is associated with EPC mobilization. Methods: Thirteen patients with refractory hyperlipidemia (analysis at the beginning and at the end of a single lipid apheresis treatment) and 10 healthy controls were included into the study. For quantifying total peripheral EPCs, CD133+/Flk-1+ myelo-monocytic blood cells were enumerated by flow cytometry. The proliferative potential of EPCs was evaluated by a "colony-forming unit" assay. In some patients, EPC eNOS expression was evaluated before and after treatment. Results: Circulating EPCs and the cells' proliferative activity were lower in hyperlipidemia patients as compared to controls (0.14 ± 0.07 vs. 0.6 ± 0.14, P = 0.01, and 13.9 ± 4.9 vs. 45.6 ± 8.1, P = 0.0007). Lipid apheresis treatment was not associated with an increase in total EPCs. The cells' proliferative activity was strongly stimulated by lipid apheresis as reflected by an increase in the number of EPC colonies (13.9 ± 4.9 to 34.1 ± 7.3, P = 0.035). Analysis of EPC eNOS expression revealed a threefold increase in the cellular expression intensity after lipid apheresis. Conclusions: Patients with refractory hyperlipidemia exhibit lower peripheral EPC numbers and a lower proliferative activity of circulating EPCs than healthy controls. A single lipid apheresis treatment significantly stimulates EPC proliferation, it furthermore increases cellular eNOS. In summary, these results show that lipid apheresis mediates beneficial effects on the EPC system as an essential element in the process of vascular repair in the human organism. J. Clin. Apheresis 2009. © 2009 Wiley-Liss, Inc. [source]

Nicotinamide phosphoribosyltransferase imparts human endothelial cells with extended replicative lifespan and enhanced angiogenic capacity in a high glucose environment

AGING CELL, Issue 2 2009
Nica M. Borradaile
Summary Endothelial dysfunction is a characteristic of aging-related vascular disease and is worsened during diabetes. High glucose can impair endothelial cell (EC) function through cellular accumulation of reactive oxygen species, an insult that can also limit replicative lifespan. Nicotinamide phosphoribosyltransferase (Nampt), also known as PBEF and visfatin, is rate-limiting for NAD+ salvage from nicotinamide and confers resistance to oxidative stress via SIRT1. We therefore sought to determine if Nampt expression could resist the detrimental effects of high glucose and confer a survival advantage to human vascular EC in this pathologic environment. Human aortic EC were infected with retrovirus encoding eGFP or eGFP-Nampt, and FACS-selected to yield populations with similar, modest transgene expression. Using a chronic glucose exposure model we tracked EC populations to senescence, assessed cellular metabolism, and determined in vitro angiogenic function. Overexpression of Nampt increased proliferation and extended replicative lifespan, and did so preferentially during glucose overload. Nampt expression delayed markers of senescence and limited reactive oxygen species accumulation in high glucose through a modest increase in aerobic glycolysis. Furthermore, tube networks formed by Nampt-overexpressing EC were more extensive and glucose-resistant, in accordance with SIRT1-mediated repression of the anti-angiogenic transcription factor, FoxO1. We conclude that Nampt enables proliferating human EC to resist the oxidative stress of aging and of high glucose, and to productively use excess glucose to support replicative longevity and angiogenic activity. Enhancing endothelial Nampt activity may thus be beneficial in scenarios requiring EC-based vascular repair and regeneration during aging and hyperglycemia, such as atherosclerosis and diabetes-related vascular disease. [source]

The Effects of Ethanol Consumption on Vasculogenesis Potential in Nonhuman Primates

ALCOHOLISM, Issue 1 2008
J. Koudy Williams
Background:, Vasculogenesis is essential to the preservation and repair of damaged or diseased vessels. Alcohol is the most commonly abused drug among young adults, but its effects on vessel growth and repair are unknown. The basis of vascular repair is endothelial progenitor cell (EPC) recruitment to assist in the formation of new vascular network (vasculogenesis). Therefore, the objective of this study was to measure the effects of ethanol consumption on the production, mobilization and vasculogenesis potential EPCs in nonhuman primates. Methods:, Four to five year-old (young adult) male rhesus monkeys consumed monkey chow and water (Control, n = 7), or chow and water + ethanol (Alcohol, 2.45 g/d, n = 7) for 12 months. Peripheral blood (PB) and bone marrow (BM) samples were collected for fluorescence-activated cell-sorting analysis of cell surface antigens (CD45, CD31, CD44, CD133, VEGF-R2 , or KDR); and for capillary formation on Matrigel-coated plates. Results:, There were greater numbers of nonhematopoeitic stromal cells (CD45,) and putative mesenchymal progenitor cells (CD45,/CD44+) in the PB and BM of Alcohol versus Control monkeys (p < 0.05). Additionally, there were greater numbers of EPCs (CD45,/CD133+/KDR+) in the BM and PB of Alcohol versus Control monkeys (p < 0.05). However, the EPCs of Alcohol monkeys were less likely to form capillaries on matrigel-coated plates than Control monkeys (p < 0.05). Conclusions:, Ethanol consumption in monkeys markedly increased the production and mobilization of EPCs, but decreased their ability to form capillaries. The pathophysiologic consequences of such effects are unclear, but may represent an ethanol-induced chronic stress on the BM, resulting in EPC. [source]

Novel renoprotective actions of erythropoietin: New uses for an old hormone (Review Article)

NEPHROLOGY, Issue 4 2006
SUMMARY: Erythropoietin (EPO) has been used widely for the treatment of anaemia associated with chronic kidney disease and cancer chemotherapy for nearly 20 years. More recently, EPO has been found to interact with its receptor (EPO-R) expressed in a large variety of non-haematopoietic tissues to induce a range of cytoprotective cellular responses, including mitogenesis, angiogenesis, inhibition of apoptosis and promotion of vascular repair through mobilization of endothelial progenitor cells from the bone marrow. Administration of EPO or its analogue, darbepoetin, promotes impressive renoprotection in experimental ischaemic and toxic acute renal failure, as evidenced by suppressed tubular epithelial apoptosis, enhanced tubular epithelial proliferation and hastened functional recovery. This effect is still apparent when administration is delayed up to 6 h after the onset of injury and can be dissociated from its haematological effects. Based on these highly encouraging results, at least one large randomized controlled trial of EPO therapy in ischaemic acute renal failure is currently underway. Preliminary experimental and clinical evidence also indicates that EPO may be renoprotective in chronic kidney disease. The purpose of the present article is to review the renoprotective benefits of different protocols of EPO therapy in the settings of acute and chronic kidney failure and the potential mechanisms underpinning these renoprotective actions. Gaining further insight into the pleiotropic actions of EPO will hopefully eventuate in much-needed, novel therapeutic strategies for patients with kidney disease. [source]

Circulating Endothelial Progenitor Cells After Kidney Transplantation

María José Soler
Circulating endothelial progenitor cells (EPCs) promote vascular repair and maintain integrity of the endothelial monolayer. Reduced EPCs number has been associated with endothelial dysfunction in various cardiovascular diseases. Cardiovascular disease risk is higher in renal transplant patients (RT) than the general population. We studied EPCs number and proliferation in RT, and examined the association with other cardiovascular risk factors such as reduced glomerular filtration rate (GFR) and LDL cholesterol. EPCs concentration was determined in 94 RT and 39 control subjects (C) by flow cytometry. EPCs proliferation was also studied after 7 days in culture. EPCs concentration was significantly reduced in RT versus C (median 33.5 [5,177] vs. 53 [9,257] EPCs/105 PMN cells, p = 0.006). EPCs proliferation was also reduced in RT versus C (mean ± SD; 372.7 ± 229.3 vs. 539.8 ± 291.3 EPCs × field, p = 0.003). In multiple regression analysis, GFR, HDL, LDL and body weight were independent predictors of EPCs concentration in RT (r2= 0.25, p < 0.001). EPCs number is reduced in RT, particularly in patients with reduced GFR. Moreover, EPCs from RT studied in vitro, showed reduced proliferation, which is a sign of functional impairment. These alterations may be involved in increased cardiovascular risk of RT. [source]