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Abstract: We have previously demonstrated that human adipose‐derived stem cells (hADSCs) can be differentiated into lymphatic endothelial like cells. The purpose of this study was to investigate the feasibility of utilizing the induced lymphatic endothelial like cells and decellularized arterial scaffold to construct the tissue‐engineered lymphatic vessel. The hADSCs were isolated from adipose tissue in healthy adults and were characterized the multilineage differentiation potential. Decellularized arterial scaffold was prepared using the Triton x‐100 method. ADSCs were differentiated into lymphatic‐like endothelial cells, and the induced cells were then seeded onto the decellularized arterial scaffold to engineer the lymphatic vessel. The histological analyses were performed to examine the endothelialized construct. The decellularized arterial scaffold was successfully obtained and was able to maintain its vessel morphology. The isolated ADSCs can be differentiated into osteocytes and adipocytes. After seeding onto the scaffold, the seeded cells attached and grew well on the decellularized arterial scaffold. Our preliminary results demonstrated that the induced lymphatic endothelial like cells combined with decellularized arterial scaffold could be utilized to successfully engineer the lymphatic vessel. Our findings may be helpful for the development of tissue‐engineering of the lymphatic graft. [ABSTRACT FROM AUTHOR]

Human adipose-derived stem cells (hADSCs) may provide a suitable number of progenitors for the treatment of lymphatic edema; however, to date the protocols for inducing hADSCs into this tissue type have not been standardized. We wished to investigate the induction of hADSCs into lymphatic endothelial-like cells using vascular endothelial growth factor-C156S (VEGF-C156S) and other growth factors in vitro. hADSCs from healthy adult adipose tissue were purified using enzyme digestion. Differentiation was induced using medium containing VEGF-C156S and bovine fibroblast growth factor (bFGF). Differentiation was confirmed using immunostaining for lymphatic vessel endothelial hyaluronan receptor (LYVE-1) and fms-related tyrosine kinase 4 (FLT-4), two lymphatic endothelial cell markers. The expression levels of LYVE-1, prospero homeobox 1 (PROX-1), and FLT-4 throughout induction were assessed using reverse transcriptase quantitative polymerase chain reaction. hADSCs were successfully obtained by trypsin digest and purification. Flow cytometry showed these cells were similar to mesenchymal stem cells, with a high positive rate of CD13, CD29, CD44, and CD105, and a low positive rate of CD31, CD34, CD45, and HLA-DR. Induction to lymphatic endothelial-like cells was successful, with cells expressing high levels of LYVE-1, PROX-1, and FLT-4. Adipose-derived stem cells can be induced to differentiate into lymphatic endothelial-like cells using a medium containing VEGF-C156S, bFGF, and other growth factors. This population of lymphatic endothelial-like cells may be useful for lymphatic reconstruction in the future. [ABSTRACT FROM AUTHOR]

Acellular nerve allografts can help preserve normal nerve structure and extracellular matrix composition. These allografts have low immunogenicity and are more readily available than autologous nerves for the repair of long-segment peripheral nerve defects. In this study, we repaired a 40-mm ulnar nerve defect in rhesus monkeys with tissue-engineered peripheral nerve, and compared the outcome with that of autograft. The graft was prepared using a chemical extract from adult rhesus monkeys and seeded with allogeneic Schwann cells. Pathomorphology, electromyogram and immunohistochemistry findings revealed the absence of palmar erosion or ulcers, and that the morphology and elasticity of the hypothenar eminence were normal 5 months postoperatively. There were no significant differences in the mean peak compound muscle action potential, the mean nerve conduction velocity, or the number of neurofilaments between the experimental and control groups. However, outcome was significantly better in the experimental group than in the blank group. These findings suggest that chemically extracted allogeneic nerve seeded with autologous Schwann cells can repair 40-mm ulnar nerve defects in the rhesus monkey. The outcomes are similar to those obtained with autologous nerve graft., Competing Interests: Conflicts of Interest: None declared.

Objective: To study the efficacy of intravenous urokinase administration in preventing and treating vascular crisis in limb or finger replantation (LFR)., Methods: From September, 1999 to October, 2003, 158 patients underwent RSLF in whom 600,000 U of urokinase diluted in 30 ml saline was injected intravenously after blood vessel suture. An intermittent dose (200,000 U) per 12 h given postoperatively for maintenance. A large dose of 1,000,000-1,500,000 U of urokinase was used in the event of vascular crisis. The D-dimer, fibrinogen, hematin, and blood platelet were measured in these patients before and after urokinase administration., Results: Vascular crisis was not observed in 117 patients (74.1%) undergoing LFR, and in the 41 patients who developed vascular crisis, relief was achieved by high-dose urokinase (90.2%) with failure occurring in only 4 cases (one with wrist and 3 with finger replantation) for whom re-operation was required. The result was better than those in relevant reports., Conclusion: A moderate dose of urokinase can be used after suturing the vessels and intermittent small doses prove feasible postoperatively to prevent thrombosis in RSLF. A high dose of urokinase can be safely used for vascular crisis management in the early stage.

Objective: To study the effect of vascularized fibular graft on large defects of long bones and the monitoring method for the vascular status of the grafted fibula., Methods: From March 1988 to February 1998, 30 patients with long bone defects over 6 cm in length received vascularized fibular graft including a monitoring island flap in our department to monitor the blood circulation of the fibulae., Results: Monitoring island abnormalities were indicated in 6 flaps, which accurately gave the alarm of the circulation crisis of the fibular graft. Surgical exploration was performed timely and the blood supply was recovered instantaneously. All the bone defects were healed at 6 months postoperatively. After 4 years of follow-up, all the grafted fibulae were thickened and were just like tibiae., Conclusions: A monitoring island flap is a satisfactory method for repairing large defects of the long bones and a reliable method for assessing the vascular status of the grafted fibulae.