Objective To review the methods of overcoming immunological rejection in xenotransplantation.Methods The strategies of overcoming immunological rejection in xenotransplantation were analyzed and summaried on the basis of an extensive review of the latest l iterature concerned. Results The research development of immunological rejection mechanism and molecular biological technique provided new approaches for overcoming immunological rejection in xenotransplantation. Conclusion It is only a matter of time for xenotransplantation to be appl ied cl inically.
To discuss the advantages of two flap contouring methods and to explore the best choice for the flap contouring. Methods From March 2002 to March 2006, 59 patients were admitted for a flapcontouring operation. Of the 59 patients, 40 (32 males, 8 females; average age, 34 years) underwent the multiphase lipectomy (the multiphase lipectomy group). The original flaps included the abdominal flap in 19 patients, the groin flap in 10, the thoracic flap in 4, the free anteriolateral thigh flap in 6, and the cross leg flap in 1. The flaps ranged in size from 6cm×4 cm to 32 cm×17 cm. However, the remaining 19 patients (16 males, 3 females; average age, 28 years) underwent the onephase lipectomy with skin graft transplantation(the onephase lipectomy group). The original flaps included the abdominal flap in 4 patients, the groin flap in 6, the thoracic flap in 3, and the free anteriolateral thighflap in 6. The flaps ranged in size from 4 cm×3 cm to 17 cm×8 cm. The resultswere analyzed and compared. Results In the multiphase lipectomy group, partial flap necrosis developed in 4 patients but the other flaps survived. The followedup of 27 patients for 3 months to 2 years revealed that the flaps had a good appearance and texture, having no adhesion with the deep tissues. However, the flaps became fattened in 22 patients with their body weight gaining. The patietns who had a flap gt; 5 cm×5 cm in area had their sensation functions recovering more slowly; only part of the sensations to pain and heat recovered. The two point discrimination did not recover. In the onephase lipectomy group, total graft necrosis developed in 1 patient but the healing was achieved with additional skin graft transplantation; partial graft necrosis developed in 2patients but the wounds were healed after the dressing changes; the remaining flaps survived completely. The followup of the 16 patients for 3 months to 3 years revealed that all the 16 patients had a good sensation recovery, 12 patientshad the two point discrimination lt; 15 mm, with no recurrence of the fattening of the flaps; however, the grafted skin had a more severe pigmentation, and no sliding movement developed between the skin and the tissue basement. Conclusion The multiphase lipectomy and the onephase lipectomy with skin graft transplantation are two skin flap contouring methods, which have their ownadvantages and disadvantages. Which method is taken should be based on the repair location of the 〖WT5”BZ〗skin flap and the condition of the skin flap.
Objective To observe the plastic changes of sensory nerve in terms of structure and function when targetorgan changed through making the rat model of nerve regeneration by anastomosing the proximal end of sensory nerve and the distal end of motor nerve. Methods Thirty adult SD rats (male or female), weighing 200-250 g, were randomized into three groups (n=10 per group). The left upper l imb of the each rat was used as the experimental side, while the right upper l imb as the control side. In group A, the medial antebrachial cutaneous nerve was cut 5 mm away from its origin and its proximal end was anastomozed end-to-end to the distal end of musculocutaneous nerve. In group B, the musculocutaneous nerve was cut 5 mm away from its nerve entry point and the proximal end of medial antebrachial cutaneous nerve were anastomozed end-to-end to the distal end of musculocutaneous nerve. In group C, medial antebrachial cutaneous nerve and musculocutaneous nerve were cut, without further anastomosis. Twenty-four weeks after operation, the general condition and the motion of the elbow joint of rats, the wet weight and muscle fiber cross-section area of the biceps brachii as well as the latent period and the ampl itude of the evoked potential were observed and the acetylchol inesterase (AchE) staining of nerve of proximal end of anastomosis was conducted. Results All the rats survived for 24 weeks with good general condition and without wound infection. The rats in groups A, B and C were lost the active flexion of left elbow joint after operation. The rats in groups A and B got recovered to some degree at 24 weeks. The behavioral evaluation showed that there were 7 l imbs in group A and 5 l imbs in group B scoredas 4-5 points, there was a significant difference when compared with group C (P lt; 0.05), but there was no significant difference between group A and group B (P gt; 0.05). Group A and group B were superior to group C in terms of the wet weight and the muscle fiber cross-section area of the biceps brachii (P lt; 0.05), but no significant difference between group A and group B was detected (P gt; 0.05). The evoked potential of the biceps brachii and motor nerve fibers in proximal end of anastomosis could be detected in both group A and group B. But there was no significant difference between group A and group B with respects of function recovery of elbow joint, the latent period and the ampl itude of the evoked potential of the biceps brachii and the quantity of motor nerve fiber in proximal end of anastomosis (P gt; 0.05). Conclusion The change of target organ leads to the sensory nerve plasticity structurally and functionally, which may provide a new approach for peripheral nerve repair.
Network meta-analysis (NMA) is a statistical technique that integrates data from multiple clinical studies and compares the efficacy and safety of multiple interventions, which can provide pro and con ranking results for all intervention options in the evidence network and provide direct evidence support for clinical decision-making. At present, NMA is usually based on the aggregation of the same type of data set, and there are still methodological and software difficulties in achieving cross-study design and cross-data format data set merging. The crossnma package of R programming language is based on Bayesian framework and Markov chain Monte Carlo algorithm, extending the three-level hierarchical model to the standard NMA data model to achieve differential merging of varied data types. The crossnma package fully considers the impact of risk bias caused by the combination of different types of data on the results by introducing model variables. In addition, the package provides functions such as result output and easy graphing, which makes it possible to combine NMA across study designs and evidence across data formats. In this study, the model based on crossnma package method and software operation will be demonstrated and explained through the examples of four individual participant datasets and two aggregate datasets.