Objective To study the mechanism of cytotoxic T lympocytes in the acute rejection of xenogenic liver transplantation(XLT). Methods Hamster to rat orthotopic liver transplantation model was performed with three cuff method. In XLT,lymphocytes including CD8 and CD4 subsets were observed by histology and immunohistochemistry; the expression of perforin and Fas- L was observed by immunohistochemistry; and apoptotic cells of XLT were observed in situ end-labelling of fragmented DNA. Results In the XLT, T cell infiltration firstly ocurred on the 2nd day posttansplantation and located at the portal triads; the infiltrating lymphocytes proliferated increased with time and reached the peak on the 5th to 6th days.Perforin and Fas-ligand were expressed on the 4th day after XLT, and peaked on the 5th to 6th day,and the expression of perforing was still higher than the expression of Fas-ligand. Conclusions T lymphocyte participates in the acute rejection of XLT through the expression of perforin and Fas-ligand, which leads to apoptosis or necrosis of hepatocytes.

Objective To study the occurrence of apoptosis in acute rejection of hamster-to-rat liver transplantation and the molecular mechanism. Methods On the basis of establishment of hamster-to-rat orthotopic liver transplantation, the apoptosis in xenograft were observed by histology and in situ end-lebelling of fragmented DNA;the expression of Fas-L and TGF-?1 were observed by Immunohistochemistry. Rseults In acute rejection of liver xenograft, the apoptosis of hepatocyte was detectable, meanwhile, the expression of Fas-L and TGF-?1 were found. The more severe apoptosis, the more severe acute rejection , and the more expression of Fas-L and TGF-?1 . Conclusions Apoptosis as a mechanism of cell death exists in the acute rejection of liver xenograft, and it is closely related to the expression of TGF-?1 and Fas-L.

Objective To explore the effect of long-term low dose ionizing radiation on telomere length in adults. Methods Forty female residents aged more than 55 years old from high level natural background radiation area in Yangjiang city and forty age-matched female residents from control area in Enping city were selected by quota sampling as high background group and control group, respectively. Genomic DNA was isolated from their peripheral blood. Telomere length was determined using real time q-PCR. The t-test was used to compare the square roots of the means of two groups. The individuals were divided into four groups based on ages ( 55 -, 60 -, 65 - and ≥70 ) and four groups based on BMI ( <18. 5, 18. 5-23. 99, 24. 0 -27. 99 and ≥28. 0). After adjusting age and BMI, multivariate linear regression analysis was performed to study the relationship between telomere length and cumulative exposure dose. The individuals were divided into longer telomere length group (≥2 ) and shorter telomere length group ( <2). Logistic regression analysis was performed to study the relationship between telomere length and cumulative exposure dose. Results The average cumulative dose was(169. 52 ± 27. 43)mSv for high background group and(47. 52 ± 6. 50)mSv for control group. The telomere length of high background group was( 1. 98 ± 1. 25 ) , shorter than that of control group ( 2. 69 ± 1. 44 ) with statis-tically significant difference(t=2. 24, P <0. 05). The multivariate linear regression analysis revealed that the effect of cumulative dose on telomere length was not significant ( P>0. 05 ) . Association between telomere length and cumulative dose was explored through Logistic regression, and odds ratio was taken as 0. 992(95% CI, 0. 985-0. 999 ) . There was a weak inverse association between telomere length and cumulative dose, because the odds ratio ( OR) was very close to 1. Conclusions No obvious dose-effect relationship between telomere length of residents and cumulative radiation doses was found. But the long-term low dose ionizing radiation may lead to the shortening of the telomere length in adults.

Objective To investigate the differences in output results between difference analysis software, and to provide a reference for the improvement of quality control and the standard revision of SPECT equipment. Methods The image analysis software for quality control held by 14 radiological health technical service institutions was selected as the research subjects using the cluster sampling method. The results of the comparison were analyzed and evaluated according to the Z-score method with certified reference values. Results In the comparison items of “intrinsic uniformity” and “intrinsic spatial linearity”, the number of software with suspicious, deviated and incorrect results accounted for a relatively high proportion, while the results of other comparison items were satisfactory. Conclusion The applicability of SPECT image analysis software lacks effective supervision measures. Relevant departments should introduce feasible measures to standardize the software production and update process, accelerate the construction of radiological health information reporting platform, and promote the healthy development of the radiation health testing industry.

OBJECTIVE: To explore the effect of long-term low-dose ionizing radiation exposure on arterial vascular elasticity in female residents. METHODS: A cluster random sampling method was used,95 female residents in 2 regions with high external γ radiation dose rate in the high radiation background area( HBRA) in Yangjiang City were selected as the HBRA group,and 96 female residents from the control area( CA) in Enping City were chosen as the CA group. The height,body mass,waist circumference,hip circumference and blood pressure were measured in individuals of these two groups. The fasting blood samples of elbow vein were collected to measure high-density lipoprotein cholesterol( HDL-C),low-density lipoprotein cholesterol( LDL-C),triglycerides( TG) and blood glucose. The cardio-ankle vascular index( CAVI) was measured using the blood pressure and pulse check device. RESULTS: The CAVI of the CA and HBRA groups were( 8. 09 ±1. 03) and( 8. 35 ± 1. 60) m/s,respectively. The abnormal rates of CAVI were 25. 00% and 29. 47%,respectively. The results of multiple linear regression analysis showed that after adjustment for age,HDL-C,LDL-C,TG,hypertension,abnormal glucose metabolism and abdominal obesity,the CAVI adjustment mean values of the CA and HBRA groups were8. 19 and 8. 25 m/s,respectively. The HBRA group was about 0. 73% higher than the CA group,but the difference was not statistically significant( standardized partial regression coefficient = 0. 021,P > 0. 05). After matching age of both groups,the difference of the adjusted mean of CAVI between the two groups was not statistically significant( P > 0. 05).CONCLUSION: Long-term low-dose radiation exposure is not associated with atherosclerosis in female population.

OBJECTIVE: To analyze the research status and developmental trend of open-access patents at home and abroad of radioactive decontamination technology for human body surface. METHODS: The basic information of open-access patents related to human body radioactive decontamination was searched and collected from the IncoPat Global Patent Database. Based on patent analysis method, the number of patent application, legal status, patent types, application trends, applicants, functional application fields, and citations were analyzed and compared, with focus on their research and development capabilities in domestic and foreign patent application status.RESULTS: A total of 981 patents of radioactive decontamination technology for human body surface were retrieved. Among them, 144 were domestic(14.7%) and 837 were from abroad(85.3%). After merge, 207 patents were confirmed, 88 were from domestic(42.5%) and 119 from abroad(57.5%). The top 5 countries with the most patents were China, Japan, the United States, France and Germany with patent amount of 88, 47, 20, 14 and 13 respectively,accounting for 87.9%(182/207) of all patents. Japan had a large number of patents with a stable growth; France and Germany started patent research very early; the United States focused on technology inheritance; Chinese patent applications are developing rapidly, followed by South Korea, and Russia had few open-access patents. Chinese patent applicants were mainly from Beijing with major enterprises and government organizations. Patents in China had few patent family, foreign patents had a wide distribution, 35.3% of which had more than five of the same family. The proportions of valid patents, utility model patents and patents of integrated device & technology in China were higher than that from abroad(35.2% vs 17.6%, 53.4% vs 3.4%, 62.5% vs 26.9%, P<0.01). The proportion of domestic patents citing other patents in China was lower than that from abroad(13.6% vs 52.1%, P<0.01), but the proportion of Chinese patents cited by other patents showed no statistical significance compared with that of abroad(27.3% vs 39.5%, P>0.05). CONCLUSION: Patents of radioactive decontamination technology for human body surface in China have developed rapidly in recent years. Patent emphasis is placed on integration and multifunctionality. However, the awareness of patent protection and regional layout is not strong enough, and the technical level needs to be improved. It is suggested to propose strategic deployment as soon as possible and strengthen technological research, development and innovation.