X-ray implanted in fixing the fracture localization and navigation in orthopedics / 中国组织工程研究

BACKGROUND:The traditional orthopedic fixation by C-arm positioning surface is completed, but the large C-arm injury on the human body and the long fixed time increase the suffering of patients. OBJECTIVE:To investigate the X-ray fixed in position within the orthopedic implants, navigation and effect. METHODS:Twenty-six New Zealand white rabbits were randomly divided into C-arm machine group and X-ray group, with 13 in each group. Rabbits in both groups were used to simulate soft tissue foreign body localization, intramedul ary nail implantation at distal fracture end and spinal pedicle screw entry point position. In the C-arm machine group, positioning navigation was conducted with C-arm machine. In the X-ray group, X-ray positioning navigation was used. The positioning and navigation effects were compared between the two groups. RESULTS AND CONCLUSION:(1) Compared with the C-arm machine group, the time required for navigation in the X-ray group targeting soft tissue foreign body localization, fracture distal locking intramedul ary nail implantation and pedicle screw spinal needle point location was significantly shorter (P<0.05);navigation displacement and deviation produced were significantly less (P<0.05). (2) These findings suggested that the X-ray positioning for orthopedic fixation method is relatively simple, with high availability, and can obtain a high performance-price ratio. Meanwhile, the X-ray localization can improve accuracy and shorten the fixed time.

Effects of natural and recombinant hirudin on VEGF expression and random skin flap survival in a venous congested rat model.

We aim to investigate the effects of locally injected natural and recombinant hirudin on vascular endothelial growth factor (VEGF) expression and flap survival in venous congested skin flaps using a rat model. A dorsal random skin flap (10 × 3 cm) was prepared on each of 30 Wistar rats to establish a venous congested model. The rats were randomly divided into 2 treatment groups [receiving subcutaneous injection of either natural hirudin (6 U) or recombinant hirudin (6 U)] and a control group, which received subcutaneous injection of physiologic saline. After treatment, skin flap survival rates were calculated. VEGF messenger RNA levels and VEGF-positive vessel density as a marker for VEGF levels were measured in the flaps during and after treatment. The skin flap VEGF messenger RNA levels increased in the natural hirudin-treated group. The VEGF-positive vessel density was increased in all 3 groups. Statistically significant increases of VEGF levels were observed in the natural and recombinant hirudin-treated groups compared with the control group (P < 0.05). The skin flap survival rates were improved in both hirudin treated groups. Natural and recombinant hirudin can increase VEGF expression in random skin flaps, which can potentially improve random skin flap survival in rats through angio genic mechanisms. Our results showed that hirudin treatment led to an increase in VEGF expression in the congested skin flaps. Natural hirudin demonstrated more pronounced effects than recombinant hirudin. Further studies are needed to understand the specific mechanisms.

Preparation of valsartan nanosuspensions and its in vitro dissolution / 药学学报

To increase the dissolution rate and extent of valsartan, valsartan nanosuspensions have been prepared. Controlled precipitation assisted with sonication is utilized to prepare valsartan nanosuspensions, the concentration of the drug, stabilizer and costablizer had a great effect on the stability of the preparation according to the pre-experiment. So the method of central composite design-response surface is used to optimize the prescription based on the above three factors and the particle size as the response value. The software Origin 8.0 is used to draw the view of the three-dimensional effects and 2D contour map, to get the optimal prescription area. Valsartan nanosuspensions were prepared. The mean diameter and zeta potential are about 216.6 nm and -57.7 mV, respectively. Compared with the microsuspensions and commercial preparation, the dissolution of valsartan nanosuspensions was faster and the bioavailability can be enhanced to some extent.