Objective To explore the expression and change on the neurokinin A(NKA) of rat ileum during the development. Methods PAP immunohistochemistry method and image analysis were used to detect systematically the expression of NKA in rat ileum from E13 to adult stage. Results 1.In rat ileum, the NKA-IR could first be found in the myenteric plexus at E17, and then appeared on the longitudinal muscle layer, circular muscle layer, intestinal villus, intestinal gland, submucosa and deep muscular plexus. On P30, they showed the distribution feature of adult rat.2.The results of quantitative analysis were in correspondence with the developmental change of NKA-IR in ileum.3.The NKA-IR positive cells showed the typical feature of morphology and distribution of gastrointestinal endocrine cells.Conclusion 1. The ontogeny and development of NKA in rat ileum mainly appeare in the last E1 week and P4 weeks, whereas the density of positive fiber in villus is not as same as adulthood until P60. 2.There are two key periods during the development of NKA in rat ileum. The first crucial stage is from the last El week to P1 week. The second important stage is in the end of P4 weeks. 3.The NKA-IR cells may be the endocrine cell which produces NKA in rat digestive tract.4.NKA may play an important role in the development and physiological function of rat ileum.

Objective To investigate the diagnosis,operation characteristics and clinical effect of anterior Pilon fracture.Methods A retrospective analysis was carried out to analyze 13 patients who had been treated for anterior pilon fracture from September 2012 to March 2014.All had fresh closed fracture.Mean age was 39.8 years (range,18-61 years).Injury resulted from high falls in 11 patients and falls in 2 patients.According to the preoperative imaging manifestations and four column fracture classification,the fracture type was mainly anterior column fracture.All underwent open reduction and internal fixation with buttress plates,and allograft bone was performed in 8 patients.At the last followup,American Orthopedic Foot and Ankle Society (AOFAS) ankle-hindfoot score and visual analogue scale(VAS) were employed for clinical evaluation.Results Mean period of follow-up was 15.7 months (range,12-30 months).Mean AOFAS score was 91.38 points (range,74-100 points).Excellent results were found in 10 patients,good in 2 and fair in 1,with the excellent-good rate of 92％.Mean VAS score was 1.08 points (range,0-3 points).Traumatic arthritis occurred in 1 patient.Skin necrosis occurred in 1 patient,and was cured by dressing change.There were no complications such as infection,refracture or implant failure.Conclusions Mechanism of injury in anterior pilon fracture is vertical violence when the foot in dorsiflexion position.Imaging findings are mainly characterized by the compression in anterior articular surface of the distal tibia,which is often implicated in the anterior medial malleolus but in part is combined with lateral malleolus fracture.The fracture is the result of high energy injury,and can be diagnosed by mechanism of injury and imaging manifestations.Through anterior approach,open reduction and internal fixation with buttress plates plus allogenic bone grafting obtain satisfactory outcomes.

Objective Based on hemodynamic analysis, to investigate the cause of distal re-entry tear in Stanford type B aortic dissection after thoracic endovascular aortic repair (TEVAR).Methods A patient with type B aortic dissection was reexamined regularly with computed tomography angiography (CTA) at 1st month, 6th month, 12th month and 24th month after TEVAR. Based on the CTA images in each period, three-dimensional (3D) aorta models were reconstructed to perform morphological analysis and hemodynamic simulation.Results Compared with the diameter at 1st month after TEVAR, the diameter of true lumen at 12 months after TEVAR increased by 1.8 times and the global distortion of aorta increased by 16.67%. At postoperative 1st, 6th and 12th month, the maximum blood velocities at the new entry tear in systole were 69.6%, 33.7% and 92.1% higher than the average ones at distal landing zone, and the maximum wall shear stresses (WSSs) were 2.52, 2.32 and 3.52 times of the average WSSs respectively. In addition, the maximum time-averaged WSS (TAWSS) at 1st, 6th and 12th month after TEVAR were 1.88, 2.53 and 3.62 times of the mean TAWSS respectively.ConclusionsThe morphology of the aorta remodeled after TEVAR, and a sudden change in the diameter of true lumen occurred at distal anchoring zone and continued to increase. As a result, the blood flow velocity in this area accelerated, and the intima was continuously exposed to high WSS, leading to the redissection.