AIM: To examine the 2′,5′-oligoadenylate synthetase activity and the peritoneal pathological changes when using commercially dialysates in order to reveal effects of the peritoneal dialysate biocompatibility on the immune function and morphological changes. METHODS: (1) CAPD animal models were made using dialysates. (2) Dynamic measurements of 2′,5′-oligoadenylate synthetase activity were made by paper chromatography. (3)The pathological changes of the peritoneal mesothelial cells were examined by light microscope. RESULTS: 2′,5′-oligoadenylate synthetase activities in both experimental (dialysis solution groups) and control group were increased and the mesothelial cell began to exfoliate and become thicker with the infiltration of inflammatory cells at different degrees in the experimental groups, while in the Baxter group, no active inflammation was observed. When the peritoneal dialysis stopped, activity of 2′,5′-oligoadenylate synthetase began to be normal in control group and continued to decline in experimental groups.CONCLUSION: Prolonged immune suppression existed with long-term peritoneal dialysis, causing pathological changes of the peritoneum at certain degrees. Different dialysis solutions resulted in different degrees of immuno-supression and peritoneal damages, which was relevant to the biological compatibility of the peritoneal dialysate.

Objective:To evaluate the accuracy of an ultrasound-guided robot-assisted system for percutaneous facet joint puncture in an animal experiment by registration of ultrasound images and two-dimensional X-ray fluorescence images.Methods:Six specimens of fresh adult sheep lumbar spine were prepared and soaked in gelatin solution. The specimens contained a total of 48 facet joints with 24 ones respectively on the left and right sides. Half of the joints were assigned by the random number table method into a robot-assisted group which were subjected to percutaneous facet joint puncture assisted by the ultrasound-guided robot-assisted system while the contralateral ones into a freehand group which were subjected to percutaneous facet joint puncture by freehand. In the robot-assisted group, the left facet joints were 3 L 1, 3 L 2, 3 L 3 and 3 L 4 ones while the right facet joints were 2 L 1, 3 L 2, 5 L 3 and 2 L 4 ones. In this self-control animal experiment, both the robot-assisted punctures and the freehand punctures were carried out in the same specimen. The puncture success rate, puncture needle adjustment, positioning deviation, orientation deviation and operation time were recorded. Results:The positioning deviation and orientation deviation in the robot-assisted group [(2.21 ± 1.12) mm and 1.51° ± 0.47°] were significantly lower than those in the freehand group [(3.26 ± 1.44) mm and 2.24° ± 0.89°] ( P < 0.05). All the articular facet joint punctures were successfully accomplished for the first time in the robot-assisted group while those required multiple adjustments in the freehand group. In the robot-assisted group, the total operation time [(463.84 ± 34.93) s] was significantly longer than that in the freehand group [(298.40 ± 27.48) s], but the puncture time [(37.97 ± 6.87) s] was significantly shorter than that in the freehand group [(261.61 ± 33.15) s] ( P < 0.05). Conclusion:The ultrasound-guided robot-assisted system for percutaneous facet joint puncture can lead to accurate puncture with limited needle adjustments.