Objective To explore the expression and change of ski-interacting protein (SKIP) in rats after spinal cord injury. Methods A total of 60 adult female Sprague-Dawley rats were randomly divided into sham group (n=30) and spinal cord injury (SCI) group (n=30), each group was further divided into five time points including one day, three days, five days, seven days, and 14 days with six rats in each time points. The model was established at T10 with modified Allen's technique, and the sham group only bit the lamina of rats. The hindlimbs behavior was assessed with Basso-Beattie-Bresnahan (BBB) score at each time point. The pathological changes of spinal cord neurons were detected with Nissl staining. The expression of SKIP were observed with immunofluorescence staining. Results The BBB scores were signif-icantly lower in each time point in SCI group than in the sham group (t>48.267, P<0.001). Compared with the sham group, Nissl bodies in the cytoplasm of spinal cord neurons began to disintegrate, coalesce and irregularly distribute, the neurons began to degenerate and die on the fifth day, and the damage deteriorated on the 14th day. Immunofluorescence staining showed that SKIP expression was mainly expressed in the gray matter of the spinal cord and little expressed in the white matter. The expression of SKIP gradually increased after SCI, and reached a peak on the fifth day (t=-17.035, P<0.001) and decreased significantly on the 14th day (t=3.853, P<0.05). Conclusion SKIP may be a new signaling molecule, which play an important role in neuronal apoptosis after SCI.

Objective To observe the regulative effect of high dose of glucocorticoid (GC) on protein synthesis and mRNA transcription of corticotropin-releasing hormone (CRH) in paraventricular hypothalamic nucleus (PVN) so to ascertain whether there exists difference upon effect of GC either at high dose or at normal dose. Methods A total of 60 Wistar rats were divided into five groups, ie, blank control group, 10 -6 mol/L dexamethasone (DEX) group, 10 -9 mol/L DEX group, 9 g/L saline group and group that was treated with 10 -4 mol/L RU486 first and then with 10 -6 mol/L DEX. The drugs were given through femoral vein. CRH protein expression was measured by means of immunohistochemistry and laser confocal scanning microscophy (LCSM); CRH mRNA transcription level was investigated by in situ hybridization. Results There appeared positive CRH mRNA granules in cytoplasm of PVN after administration with 10 -6 mol/L DEX for 20 minutes but could be seen positive fluorescent granules of CRH protein 30 minutes later, which was reversed at an in advance blockage of GR, as was free in 10 -9 mol/L DEX group, 9 g/L saline group and blank control group. Conclusions High dose of GC can up regulate CRH gene expression in PVN and differs much from the traditional effect of GC at normal dose, as may be due to that high dose of GC exerts effects depending on membrane glucocorticoid receptor but normal dose of GC dose via iGR.

Objective To explore the expression and the changes of ski with time in the injured spinal cord in rats. Methods Sixty adult female Sprague-Dawley rats were randomly divided into sham group (n=30) and injury group (n=30), each group were further divided into 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks subgroups, with 6 rats in each subgroup. Spinal cord injury at T10 was established with modi-fied Allen's technique (10 g × 25 mm) in the injury group. The hindlimbs behavior of rats was rated with Basso-Beattie-Bresnahan (BBB) scores 1 day, 3 days, 1 week, 2 weeks, 4 weeks, 8 weeks and 12 weeks after spinal cord injury. Three rats in each subgroup were stained with HE staining to observe the pathological changes of the spinal cord and the formation of cavity. The other 3 rats were analyzed with im-munofluorescence staining of ski and semi quantitative analysis. Results The BBB scores of each time point were less in the injury group than in the sham group (P<0.05). Necrosis was the major pathological change in the injury groups 1 and 2 weeks after injury;cystic cavity completely formed 4 weeks after injury, with dense scar tissue around it;there was no significant change in the cavity and scar 8 and 12 weeks after injury, however, the adjacent spinal cord was obviously thinner. Ski expressed little in the normal spinal cord, and expressed more and more after injury, peaked at 8 weeks and decreased then. Ski was mainly observed in white matter in the sham group and 12 weeks injury subgroup, which was in gray matter 2, 4 and 8 weeks after injury. Ski was highly expressed around the cavity in injury center and formed high expression band. Conclusion Ski expresses after spinal cord injury in rats, that may be associated with the activation and prolif-eration of astrocytes and the formation of glial scar.

Objective To study the differentiation and proliferation ability of the spinal neural stem cells (NSCs) at different gestational ages in fetal rats. Methods Sprague-Dawley fetal rats were divided into group A (12 days of pregnancy), group B (14 days of pregnancy) and group C (16 days of pregnancy). NSCs were separated with enzyme-assisted microdissection. The diameter and numbers of NSCs balls were measured at different time. The cell growth curve was drawn with CCK8 colorimeter. NSCs were identified with BrdU/Nestin immunohistochemical staining. They were induced with 10% fetal bovine serum for 10 days, and the expression of β-tubulinⅢ and glial fibrillary acidic protein was detected with immunocytochemistry. Results There were cells expressed BrdU, Nestin, β-tubulinⅢ and GFAP in all the group. The most cells (22.74±0.79%) expressed β-tubulinⅢ in the group B, but no significant difference between group B and group C. The cell vitality on the 5th day of third-generation neural stem cells was the most in group B. Conclusion For enzyme-assisted microdissection, it may obtain more neurons to isolate the neural stem cells from 14 days of pregnancy pregnant rats.

Objective To explore the learning and memory impairment and pathology in hippocampus in rats after spinal cord contu-sion. Methods 36 adult female Sprague-Dawley rats were randomly divided into sham group (n=18) and spinal cord injury group (n=18). Spinal cord injury model at T10 was established with modified Allen's technique (10 g × 25 mm). The hindlimbs behavior of rats was rated with Basso-Beattie-Bresnahan (BBB) scores once a week for 5 weeks. They were tested with motor evoked potentials (MEP) and Morris wa-ter maze 5 weeks after injury. The pathology of hippocampus was detected with HE staining 1 week, 3 weeks and 5 weeks after injury, 4 rats in a group, repectively. Results The BBB scores were significantly lower in the spinal cord injury group than in the sham group at each time point (P<0.05). The latencies of both N1 and P1 wave of MEP were significantly longer in the spinal cord injury group than in the sham group (P<0.001), while the amplitudes were significantly less (P<0.001). For the Morris water maze, the latency of arrival platform were sig-nificantly longer in the spinal cord injury group than in the sham group (P<0.001), and the time in target was significantly less (P<0.001), with more systematic positioning or annular positioning, while the sham group with more space-based positioning. Morphologically abnor-mal cells in hippocampus gradually increased since the first week after injury, with the decrease of cells survival, while it was normal in the sham group. Conclusion Spinal cord contusion can cause learning and memory impairment in rats, which may be related to injury in hippo-campus.

Objective:To develop an information system for testing radiological protection that can interface with National Radiation Health Information Platform/Medical Radiation Monitoring Subsystem and to improve the testing efficiency.Methods:Complying with the relevant national regulations and standards, the analysis was carried out of demand investigation and system modeling. An information system for testing radiological protection was established using B/S architecture, comprising three modules such as testing, audit and system management. The users at four levels were set of administrator, inspector, auditor and report issuer.Results:Based on test result, the developed information system has been shown to realize the informatization of the whole process from filling, auditing, issuing, issuing of the testing report to data uploading, with improved testing efficiency.Conclusions:The developed information system for testing radiological protection can improve the testing efficiency, and can be successfully interfaced with the National Radiation Health Information Platform/Medical Radiation Protection Monitoring Subsystem.

Objective:To evaluate 90Y activity concentration in renal excretions during the first 48 hours after being treated with 90Y resin microspheres seleceive internal radiation therapy(SIRI) and to provide advice on the management of patient excreta after surgery. Methods:After surgery, urine excreted from 3 patients during 0-24 h and 24-48 h was collected respectively, and the 90Y activity concentration in urine was tested and analyzed. Results:90Y radioctivity in the urine excreted from 3 patients after surgery was (1 266±258)kBq/GBq during 0-24 h and (140±106) kBq/GBq during 24-48 h, respectively, and 90Y activity concentration were (640±113) kBq/L during 0-24 h and (53±12) kBq/L during 24-48 h. Conclusions:90Y radioactivity in patient′s urine excreted at 1 d was about 10 times higher than that at 2 d. After surgery, patients can accelerate the reduction of free 90Y activity by increasing excretion. Urine excreted by the patients during hospitalization should be handled in accordance with the requirements of the national standard HJ 1188-2021 Radiation protection and safety requirements for nuclear medicine.