BACKGROUND:With the deepen understanding on the biological function of Rho/ROCK pathway, new ROCK inhibitors continue to be discovered, and ROCK inhibitors show good promoting effects on the survival, proliferation and migration of keratocytes. Research on ROCK inhibitors wil provide more donor materials or seed cels for regenerative medicine and clinical cel transplantation. OBJECTIVE:To summarize and explore the progress in the treatment and application of corneal disease using the ROCK inhibitors Y-27632 and Y-39983. METHODS:The PubMed database and CNKI database were retrieved by computer to search the relevant literature published between 2008 to 2015 using the key words of “corneal endothelial cel, corneal epithelial cel, ROCK inhibitor, Y-39983, Y-27632” in English and Chinese, respectively. Relevant articles in line with the theme were screened and analyzed. RESULTS AND CONCLUSION:Totaly 264 papers were initialy searched. At last, 45 papers were selected. Currently there are two main ROCK inhibitors: Y-27632 and Y-39983, but both of which are stil in basic research stage and clinical testing stage. Y-27632 promotes the proliferation and activity of corneal epithelial stem cel after resuscitation; Y-39983 as a novel ROCK inhibitor can be better to inhibit Rho kinases activity than Y-27632, thereby more effectively promoting the healing of the corneal endothelium. There are many studies on the application of ROCK inhibitors in corneal treatment, but not a stable method established to obtain seed cels. Each method has its own advantages and disadvantages, and how to overcome these disadvantages and to find fast and stable access to seed cels is the future direction of development.

Objective:To investigate the risk factors and prognostic effects of intolerance of early enteral nutrition after surgery for gastric cancer.Methods:The clinical data of 75 patients with gastric cancer who were admitted in the Shoukang hospital and received early enteral nutrition after surgery were retrospectively retrived and analyzed.Patients were divided into the tolerance group and the non-tolerance group according to whether the patients developed the symtoms of nausea,vomiting,abdominal pain,distention and diarrhea after early enteral nutrition.Results:51 patients (68％) showed enteral nutrition intolerance after early enteral nutrition postoperatively,whereas 24 (32％) were in the tolerance group.The activity time out of bed on the first postoperative day,the time of initiation of enteral nutrition,and nutrition pump were significantly different between two groups.Logistic analysis revealed that the activitity time and nutrition pump were independent favourable factors.Besides,patients with intolerance had longer time to exhaust and defecation,and postoperative hospital stay.Conclusion:Insufficient postoperative activity time and nonuse of nutrition pump are risk factors of intolerance of early enteral nutrition,which may slow the recovery of patients.

OBJECTIVE:To study the relative bioavailability,pharmacokinetics and bioequivalence of domestic nisoldipine tablets in healthy volunteers.METHODS:A single oral dose of 10 mg test and reference nisoldipine tablets were given to 24 male healthy volunteers in an open randomized 2?2 latin square design.The plasma concentrations of nisoldipine at different time points were determined by LC-MS and the pharmacokinetic parameters of the two kinds of tablets were computed and their bioequiavailability was evaluated.RESULTS:The main pharmacokinetic parameters of the test vs.reference formulations of nisoldipine in 24 healthy volunteers were as follows:Cmax(2.94?2.78)ng?mL-1 vs.(3.22?2.16)ng?mL-1,tmax(1.70?1.00)h vs.(1.40?1.00)h,t1/2(6.81?4.11)h vs.(5.55?2.35)h,AUC0～24(10.60?7.70)ng?h?mL-1 vs.(9.90?6.76)ng?h?mL-1,AUC0～∞(11.30?7.90)ng?h?mL-1 vs.(10.20?7.00)ng?h?mL-1.The relative bioavailability of domestic nisoldipine tablets was(110.3?30.8)%.CONCLUSION:The reference preparation and the test preparation of nisoldipine tablets were proved to be bioequivalent.

OBJECTIVESTo compare the stability of an enhanced load sharing dynamic pedicle screw fixation device with its equivalent rigid device and to evaluate biomechanical roles of the dynamic fixation.

METHODSA model of L(1) body fracture was produced on seven specimens of fresh adult cadaver spine from T(10) to L(4). Both dynamic and rigid devices were applied in the specimens to strength the injured level. Ranges of three dimensional movements and stiffness under flexion-compression were measured in intact, injured and stabilized specimens.

RESULTSBoth dynamic and rigid devices were found to provide significant stability for injured segment in flexion-extension and lateral bending. In axial rotation, the devices could restore the stability to levels similar to those in an intact spine. Results indicated 40% increase in range of motion in flexion-extension and 24.1 Nmm reduction in stiffness of flexion-compression for dynamic device, compared with the rigid device.

CONCLUSIONThe dynamic device offers a design that may enhance load sharing without sacrificing the stability and will decrease stress-shielding and stress concentration.

Biomechanical Phenomena ; Bone Screws ; Fracture Fixation, Internal ; instrumentation ; Humans ; Male ; Spinal Injuries ; surgery

Objective:To compare the biomechanical properties of triangular supporting fixation and Gamma nail fixation for intertrochanteric fractures of the femur.Methods:The femoral CT imaging data provided by a healthy adult male volunteer aged 40 years, height 172 cm, and weight 75 kg were used to reconstruct the femur model using Mimics 21.0 software and Geomagics 2013 software. Evans type I intertrochanteric fracture models were established using UG12.0 software, and Gamma nail and triangular supporting intramedullary nail models were reconstructed to simulate intertrochanteric fracture internal fixation, respectively. In Abaqus software, two internal fixation models of Gamma nail and triangular supporting intramedullary nail in standing state are simulated, and the stress peaks of the main nail, fixation screw and bone substance were collected, also the stress peak of supporting screw of the triangular supporting intramedullary nail is obtained. Additionally, the maximum displacement of the fracture model fixed by Gamma nail and triangular supporting intramedullary nail is measured.Results:Under the load of 1 200 N, the peak stress of the two fracture internal fixation models was located in the main nail, in which the peak stress of the triangular supporting intramedullary nail was 233.73 MPa, which was 11.9% lower than that of the Gamma nail (265.21 MPa); the peak stress of the fixation screw was located in the contact area between the pressure screw and the main nail, which was 23.2% lower in triangular supporting intramedullary nail than that of the Gamma nail (138.86 MPa vs. 180.75 MPa); the peak stress of the bone model was located in the medial cortex of the femur, which was 61.67 MPa and 32.38 MPa, respectively, 47.5% lower in the triangular supporting intramedullary nail than that of the Gamma nail; the peak stress of the supporting screw in the triangular supporting intramedullary nail was 92.04 MPa. The maximum displacement of the fracture model fixed with triangular supporting intramedullary nail was 17.34 mm, which was 10.5% less than the maximum displacement of the fracture model fixed with Gamma nail (19.37 mm). Conclusion:Compared with Gamma nail, triangular supporting intramedullary nail fixation can significantly improve the stability of intertrochanteric fractures and stress distribution as well as reduce stress peak and stress concentration area, which is helpful to improve the efficacy of intertrochanteric fractures.

Objective:To study the morphologic features of the fusion site of proximal tibial epiphysis in normal adults and analyze its potential clinical value based on Mimics three-dimensional (3D) reconstruction.Methods:CT images of knee joint of 68 patients without obvious abnormalities of lower limbs were retrospectively analyzed in electronic database of our hospital from June 2020 to June 2021, including 41 males and 27 females. The mean age of the patients was 38.7±8.4 years (range, 25-55 years), and the mean body mass index (BMI) was 25.3±4.0 kg/m 2 (range, 18.75-41.8 kg/m 2). Mimics 3D reconstruction technique was used to reconstruct the 3D model of the proximal tibia and epiphyseal fusion site. The relationship between the surface area of epiphyseal fusion site and age and BMI was studied, and the changes of cortical thickness and density at epiphyseal fusion site were also explored. Results:The fusion site of adult epiphyseal reconstructed by Mimics 3D reconstruction is a complex wavy surface structure in 3D space. The surface area of the epiphyseal fusion site was 2,994.7±645.3 mm 2 (range, 1,704.0-4,650.0 mm 2) obtained by 3-Matic Research 12.0. The fusing area of male epiphysis was 3 269.3±533.9 mm 2 than that of female 2,577.6±578.7 mm 2, the difference was statistically significant ( t=5.06, P<0.001). However, there was no significant correlation between the epiphyseal fusion site surface area and age ( R2=0.02, P=0.268) and BMI ( R2=0.04, P=0.125). Mimics software was used to obtain the CT values of bone cortex at the epiphysis line and the distal end of the epiphysis line at 10 mm and 20 mm levels as 451.059±74.953 Hu, 1,018.412±125.732 Hu and 1,414.162±107.848 Hu, respectively. The thickness of bone cortex was 1.814±0.090 mm, 2.511±0.089 mm and 3.189±0.185 mm at 10 mm and 20 mm layers of epiphysis line and distal epiphysis line, respectively. Conclusion:In this study, Mimics 3D reconstruction technique was used to visualize the fusion site of the proximal tibial epiphysis in normal adults. The epiphyseal fusion site of adult is a undulating plate-like structure, and the cortical bone density of epiphyseal fusion site is low and thin, theoretically, it is easy to fracture under indirect violence.

Objective:To characterize the biomechanics of distal dynamic locking and distal static locking of proximal femur bionic nails (PFBN) in fixation of intertrochanteric fractures by a finite element analysis.Methods:The CT image data from the hip to the upper tibia from an adult male volunteer were used to establish a three-dimensional model of the femur by Mimics 20.0 and Geomagic 2013 which was processed further into a model of Evans type I intertrochanteric fracture by software NX 12.0. With reference to the internal fixation parameters commonly used, 4 models of PFBN fixation were established: distal single transverse nail dynamic locking (model A), single oblique nail dynamic locking (model B), single nail static locking (model C) and double nail dynamic locking (model D). Abaqus 6.14 software was used to load and analyze the internal fixation stresses and displacements of fracture ends.Results:Under a 2100N loading, the peak stress was located upon the main nail in the 4 models. The smallest peak stress upon the main nail was in Model D (161.9 MPa), decreased by 15.9% compared with model A (192.5 MPa), by 15.6% compared with model B (191.9 MPa), and by 0.9% compared with model C (163.3 MPa). The peak stress upon the fixation screw was the largest in model A (95.3 MPa), the smallest in model B (91.5 MPa), and 91.5 MPa and 92.2 MPa in models C and D, respectively. The overall displacements of the implants, in a descending order, were 10.14 mm in model A, 10.10 mm in model B, 10.09 mm in model C, and 10.05 mm in model D. Similarly, the displacements of fracture ends were 0.125 mm in model A, 0.121 mm in model B, 0.110 mm in model C, and 0.098 mm in model D.Conclusion:Compared with dynamic locking, distal static locking of PFBN provides a better mechanical stability and reduces stress concentration upon internal fixation.