BACKGROUND:Fisher-Lewis rat kidney transplant models are the international common chronic renal alograft rejection models, but their application is greatly limited because of difficulty in model preparation and high costs. OBJECTIVE:To explore a new method of establishing SD-Wistar rat models of chronic renal alograft rejection. METHODS: Fifty-six pairs of SD-Wistar rats were subjected to left kidney orthotopic transplantation. The right kidneys of the recipients were intact and used as internal controls. 23 rat recipients were randomly divided into model group (n=15) and control group (n=8). The rats in the model group were injected with cyclosporine microemulsion for 10 days (2 mg/kg/day,i.p.) after kidney transplantation. The rats in the control group were not treated with immunosuppressive therapy. RESULTS AND CONCLUSION:The irreversible acute rejection occurred in al the transplanted kidneys of rats in the control group within 4 weeks, leading to the necrosis of transplanted kidney. Moderate inflammatory cel infiltration appeared in the transplanted kidneys of rats in the model group at 4, 8 and 12 weeks after transplantation. Typical histopathological changes of chronic rejection were observed within 12 weeks after transplantation. The Banff total scores were increased with time after transplantation. Al these histopathological changes were not observed in the intact right kidneys of rat recipients in both groups. The valey value of 

Objective:To observe the regulatory effect of microRNA-10b(miR-10b)on the immune effect of glioma cells and explore its mechanism.Methods:Human glioma cell U251 was cultured to obtain cells in logarithmic growth stage.The cell suspen-sion was prepared according to the concentration of 1.0×105 cells/ml,and the control group,overexpression group,low expression group and blank group were set up,with 6 wells in each group.The negative control,miR-10b mimics and miR-10b inhibitor were transfected by liposome transfection in control group,overexpression group and low expression group,respectively.The blank group was given the same amount of sterile normal saline.Natural killer(NK)cells from peripheral blood of a healthy volunteer was isolated and cultured.The killing activity of NK cells was detected by MTT method.The expression of NK cell activated receptor(NKG2D)on the surface of NK cells in each group were detected by flow cytometry,and the expression of major histocompatibility complex class Ⅰ chain-related gene A(MICA),UL16 binding protein 2(ULBP2)and UL16 binding protein 3(ULBP3)on the surface of U251 hu-man glioma cells in each group were detected.Results:The transfection efficiency of control group,overexpression group and low ex-pression group were(93.55±2.05)％,(95.67±3.14)％,(94.18±3.26)％,respectively.Compared with control group and blank group,the expression of miR-10b increased in overexpression group and decreased in low expression group,and the difference were statisti-cally significant(P<0.05).There was no significant difference in the expression of miR-10b between control group and blank group(P>0.05).Compared with control group and blank group,the killing activity of NK cells with different effect target ratios in overex-pression group decreased,the expression of NKG2D decreased,the killing activity of NK cells with different effect target ratios in low expression group increased,and the expression of NKG2D increased,and the difference were statistically significant(P<0.05).The killing activity of NK cells in each group increased with the increase of effect target ratio,and the difference were statistically signifi-cant(P<0.05),and there was no significant difference in NK cell killing activity and NKG2D expression between control group and blank group(P>0.05).Compared with control group and blank group,the expression of MICA,ULBP2 and ULBP3 on the surface of human glioma cell U251 in overexpression group decreased,and the expression of MICA,ULBP2 and ULBP3 on the surface of human glioma cell U251 in low expression group increased,the difference were statistically significant(P<0.05),and there was no signifi-cant difference in the expression of MICA,ULBP2 and ULBP3 on the surface of U251 glioma cells between control group and blank group(P>0.05).Conclusion:Inhibiting the expression of miR-10b can increase the expression of NKG2D on the surface of NK cells and MICA,ULBP2 and ULBP3 on the surface of human glioma cell U251,and enhance the killing activity of NK cells against human glioma cell U251.

Objective:To investigate the relationship between tube voltage kV value for head and neck CT angiography and body weight.Methods:A total of 120 patients with suspected vascular disease of the head and neck who underwent CT angiography of the head and neck in Beihai People's Hospital from January 2020 to May 2022 were included in this study. Patients were divided into three groups according to different tube voltages: group A (tube voltage 120 kV, n = 45), group B (tube voltage 100 kV, n = 45) and group C (tube voltage 80 kV, n = 30). Patients in group A were divided into group A1 (< 70 kg, n = 15), group A2 (70-85 kg, n = 15) and group A3 (> 85 kg, n = 15) according to different body weights. Patients in group B were divided into group B1 (< 70 kg, n = 15), group B2 (70-85 kg, n = 15) and group B3 (> 85 kg, n = 15) according to different body weights. Patients in group C were divided into group C1 (< 70 kg, n = 15) and group C2 (70-85 kg, n = 15) according to different body weights. Group C3 was not used. The contrast medium used was Loversol. The CT value, image noise, signal-to-noise ratio, contrast to noise ratio, and effective radiation dose of arterial vessels in each group were measured. The images were subjectively evaluated by two physicians who had senior professional titles using a 5-point rating scale. Results:Subjective score of image quality was all ≥ 3 grade in each group. There was no significant difference in image quality rating between groups A1 and A2 and groups B1, B2, and C1. There was a remarkable difference in image quality rating between groups A3, B3, and C2 and the other groups. There was a significant difference in the CT value of blood vessels at four different levels between groups A1, B1 and C1 ( F = 76.82, 64.62, 98.79, 71.85, all P < 0.001). There was a significant difference in CT value of blood vessels at four different levels between groups A2, B2 and C2 ( F = 159.82, 112.33, 108.22, 135.18, all P < 0.001). There was a significant difference in CT value of blood vessels at four different levels between groups A3 and B3 ( t = 4.40, 4.27, 3.91, 3.59, all P < 0.05). In groups B3 and C2, the image noise was remarkably increased, signal to noise ratio and contrast to noise ratio were remarkably decreased compared with those in the other groups. The effective radiation dose of arterial vessels in group B1 was 47% lower than that in group A1 and the effective radiation dose of arterial vessels in group C1 was 73% lower than that in group A1 ( F = 116.18, P < 0.001). The effective radiation dose of arterial vessels in group B2 was 49% lower than that in group A2, and the effective radiation dose of arterial vessels in group C2 was 66% lower than that in group A2 ( H = 35.40, P < 0.001). The effective radiation dose in group B3 was 35% lower than that in group A3 ( t = 3.59, P < 0.05). Conclusion:In CT angiography of the head and neck, the selection of tube voltage kV value is related to body weight. Tube voltage 80 kV is suitable for patients with a body weight < 70 kg, tube voltage 100 kV for patients with a body weight of 70-85 kg, and tube voltage 120 kV for patients with a body weight > 85 kg. These tube voltages can decrease effective radiation dose and ensure image quality, meeting the requirement for clinical diagnosis.