Objective:To evaluate the potential value of 18×10 3 translocator protein (TSPO) radioligand ( N, N-diethy1-2-(2-(4-(2- 18F-fluoroethoxy) phenyl)-5, 7-dimethylpyrazolo[1, 5-A]pyrimidin-3-yl)acetamide, 18F-DPA-714) PET compared with conventional MR in the detection of autoimmune encephalitis (AE), the correlation with clinical symptoms, and the monitoring of immunotherapy efficacy in patients with AE. Methods:From December 2021 to June 2024, 45 AE patients (17 males, 28 females, age (38.3±17.0) years) diagnosed at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine and 10 healthy volunteers (7 males, 3 females, age (28.7±5.1) years) were enrolled in this prospective study. All participants underwent baseline 18F-DPA-714 PET/MR scans, and 23 of these AE patients underwent further follow-up 18F-DPA-714 PET/MR scans. 18F-DPA-714 PET positivity was defined as having an uptake intensity threshold higher than the mean SUV ratio (SUVR)+ 2 s of the corresponding brain region in healthy controls. MR positivity was defined as abnormal hyperintensity in a specific brain region or multiple brain regions on the T 2 fluid attenuated inversion recovery (FLAIR). The positive detection rates of 18F-DPA-714 PET and MR was analyzed using McNemar χ2 test, and the differences in the uptake intensity (SUVR) of 18F-DPA-714 between symptomatic and non-symptomatic groups, and between remission and non-remission groups after immunotherapy were compared using independent-sample t test or Wilcoxon rank sum test. Spearman rank correlation analysis was used to analyze the correlation between the changing rate of SUVR and the changing of the modified Rankin Scale (mRS) score before and after treatment. Results:The positive detecting rate of 18F-DPA-714 PET for AE was significantly higher than that of MR (73.3%(33/45) vs 35.6%(16/45); χ2=11.56, P=0.001). The cerebellar SUVR of ataxia patients was significantly higher than that of asymptomatic patients (1.22(1.06, 1.33) vs 1.08(0.99, 1.20); Z=-2.14, P=0.034). Follow-up imaging showed that the SUVR of patients in the remission group after immunotherapy was significantly lower than that in the non-remission group ((-15.19±10.17)% vs (14.26±13.36)%; t=5.81, P<0.001). There was a significant correlation between the changing rate of SUVR and the changing of the mRS score before and after treatment ( rs=0.65, P<0.001). Conclusion:Compared with conventional MR, 18F-DPA-714 PET has a higher positive detecting rate for AE, and has the potential to reflect the clinical symptoms of AE and monitor the efficacy of immunotherapy.

Objective·[18F]F-FMISO and[18F]F-FLT are specific PET imaging agents for detecting the hypoxia microenvironment and cell proliferation,respectively.This study aims to visualize and monitor the impact of drug resistance in pancreatic cancer on the hypoxia microenvironment and cell proliferation through[18F]F-FMISO and[18F]F-FLT PET/CT dual-nuclide imaging,with the goal of providing a theoretical basis for clinical application.Methods·The CCK-8 assay was conducted to assess drug resistance in the PANC-1/R(PR)pancreatic cancer cell line compared to the parental PANC-1(P)cell line.Subcutaneous xenograft models of pancreatic cancer were established by injecting male BALB/c nude mice with pancreatic cancer cells into the left axillary subcutaneous region.Subgroups were treated with gemcitabine(GEM)chemotherapy starting on day 18(18D-G group)or day 12(12D-G group)after inoculation of tumor cells.[18F]F-FMISO and[18F]F-FLT PET/CT imaging were performed before and after treatment to obtain semi-quantitative parameters(maximum standardized uptake value,SUVmax).ΔSUVmax was calculated by using the following equation:ΔSUVmax=(SUVmax of second imaging-SUVmax of first imaging)/SUVmax of first imaging.Receiver operating characteristic(ROC)curves were used to determine the optimal threshold for the semi-quantitative parameters to assess pancreatic cancer drug resistance.Results·The CCK-8 assay confirmed that the PR cells exhibited high resistance to GEM,with a resistance index of 4.24(n=5).In vivo experiments showed that GEM chemotherapy significantly inhibited tumor growth and prolonged survival in the parental pancreatic cancer group(12D-G group,P=0.025),whereas GEM chemotherapy accelerated tumor growth and shortened survival(18D-G and 12D-G,P=0.025)in the drug-resistant pancreatic cancer group.In addition,in the non-chemotherapy group,ΔSUVmax-FLT might be negatively correlated with survival time,while in the chemotherapy group,both ΔSUVmax-FMISO and ΔSUVmax-FLT were negatively correlated with survival time(P=0.050,P=0.006).In the 18D-G and chemotherapy group,the second imaging showed significantly lower ΔSUVmax-FMISO and ΔSUVmax-FLT in P tumors compared to PR tumors(P=0.045,P=0.050).In the 12D-G and chemotherapy group,the second imaging showed slightly lower ΔSUVmax-FLT in P tumors compared to PR tumors(P=0.051).ROC analysis identified the optimal threshold for assessing pancreatic cancer drug resistance:when ΔSUVmax-FLT=0.45 in the non-chemotherapy group,the sensitivity and specificity were 100.00%and 50.00%,respectively;when ΔSUVmax-FMISO=0.37 and ΔSUVmax-FLT=0.36 in the chemotherapy group,the sensitivity and specificity were 100.00%and 83.33%,respectively.Conclusion·[18F]F-FMISO and[18F]F-FLT PET/CT dual-nuclide imaging can be used to assess drug resistance in pancreatic cancer.The comparison of[18F]F-FMISO and[18F]F-FLT PET differences before and after chemotherapy provides the most accurate prediction of drug resistance and survival time.

Objective·[18F]F-FMISO and[18F]F-FLT are specific PET imaging agents for detecting the hypoxia microenvironment and cell proliferation,respectively.This study aims to visualize and monitor the impact of drug resistance in pancreatic cancer on the hypoxia microenvironment and cell proliferation through[18F]F-FMISO and[18F]F-FLT PET/CT dual-nuclide imaging,with the goal of providing a theoretical basis for clinical application.Methods·The CCK-8 assay was conducted to assess drug resistance in the PANC-1/R(PR)pancreatic cancer cell line compared to the parental PANC-1(P)cell line.Subcutaneous xenograft models of pancreatic cancer were established by injecting male BALB/c nude mice with pancreatic cancer cells into the left axillary subcutaneous region.Subgroups were treated with gemcitabine(GEM)chemotherapy starting on day 18(18D-G group)or day 12(12D-G group)after inoculation of tumor cells.[18F]F-FMISO and[18F]F-FLT PET/CT imaging were performed before and after treatment to obtain semi-quantitative parameters(maximum standardized uptake value,SUVmax).ΔSUVmax was calculated by using the following equation:ΔSUVmax=(SUVmax of second imaging-SUVmax of first imaging)/SUVmax of first imaging.Receiver operating characteristic(ROC)curves were used to determine the optimal threshold for the semi-quantitative parameters to assess pancreatic cancer drug resistance.Results·The CCK-8 assay confirmed that the PR cells exhibited high resistance to GEM,with a resistance index of 4.24(n=5).In vivo experiments showed that GEM chemotherapy significantly inhibited tumor growth and prolonged survival in the parental pancreatic cancer group(12D-G group,P=0.025),whereas GEM chemotherapy accelerated tumor growth and shortened survival(18D-G and 12D-G,P=0.025)in the drug-resistant pancreatic cancer group.In addition,in the non-chemotherapy group,ΔSUVmax-FLT might be negatively correlated with survival time,while in the chemotherapy group,both ΔSUVmax-FMISO and ΔSUVmax-FLT were negatively correlated with survival time(P=0.050,P=0.006).In the 18D-G and chemotherapy group,the second imaging showed significantly lower ΔSUVmax-FMISO and ΔSUVmax-FLT in P tumors compared to PR tumors(P=0.045,P=0.050).In the 12D-G and chemotherapy group,the second imaging showed slightly lower ΔSUVmax-FLT in P tumors compared to PR tumors(P=0.051).ROC analysis identified the optimal threshold for assessing pancreatic cancer drug resistance:when ΔSUVmax-FLT=0.45 in the non-chemotherapy group,the sensitivity and specificity were 100.00%and 50.00%,respectively;when ΔSUVmax-FMISO=0.37 and ΔSUVmax-FLT=0.36 in the chemotherapy group,the sensitivity and specificity were 100.00%and 83.33%,respectively.Conclusion·[18F]F-FMISO and[18F]F-FLT PET/CT dual-nuclide imaging can be used to assess drug resistance in pancreatic cancer.The comparison of[18F]F-FMISO and[18F]F-FLT PET differences before and after chemotherapy provides the most accurate prediction of drug resistance and survival time.

Objective:To evaluate the potential value of 18×10 3 translocator protein (TSPO) radioligand ( N, N-diethy1-2-(2-(4-(2- 18F-fluoroethoxy) phenyl)-5, 7-dimethylpyrazolo[1, 5-A]pyrimidin-3-yl)acetamide, 18F-DPA-714) PET compared with conventional MR in the detection of autoimmune encephalitis (AE), the correlation with clinical symptoms, and the monitoring of immunotherapy efficacy in patients with AE. Methods:From December 2021 to June 2024, 45 AE patients (17 males, 28 females, age (38.3±17.0) years) diagnosed at Ruijin Hospital, Shanghai Jiao Tong University School of Medicine and 10 healthy volunteers (7 males, 3 females, age (28.7±5.1) years) were enrolled in this prospective study. All participants underwent baseline 18F-DPA-714 PET/MR scans, and 23 of these AE patients underwent further follow-up 18F-DPA-714 PET/MR scans. 18F-DPA-714 PET positivity was defined as having an uptake intensity threshold higher than the mean SUV ratio (SUVR)+ 2 s of the corresponding brain region in healthy controls. MR positivity was defined as abnormal hyperintensity in a specific brain region or multiple brain regions on the T 2 fluid attenuated inversion recovery (FLAIR). The positive detection rates of 18F-DPA-714 PET and MR was analyzed using McNemar χ2 test, and the differences in the uptake intensity (SUVR) of 18F-DPA-714 between symptomatic and non-symptomatic groups, and between remission and non-remission groups after immunotherapy were compared using independent-sample t test or Wilcoxon rank sum test. Spearman rank correlation analysis was used to analyze the correlation between the changing rate of SUVR and the changing of the modified Rankin Scale (mRS) score before and after treatment. Results:The positive detecting rate of 18F-DPA-714 PET for AE was significantly higher than that of MR (73.3%(33/45) vs 35.6%(16/45); χ2=11.56, P=0.001). The cerebellar SUVR of ataxia patients was significantly higher than that of asymptomatic patients (1.22(1.06, 1.33) vs 1.08(0.99, 1.20); Z=-2.14, P=0.034). Follow-up imaging showed that the SUVR of patients in the remission group after immunotherapy was significantly lower than that in the non-remission group ((-15.19±10.17)% vs (14.26±13.36)%; t=5.81, P<0.001). There was a significant correlation between the changing rate of SUVR and the changing of the mRS score before and after treatment ( rs=0.65, P<0.001). Conclusion:Compared with conventional MR, 18F-DPA-714 PET has a higher positive detecting rate for AE, and has the potential to reflect the clinical symptoms of AE and monitor the efficacy of immunotherapy.

Animal health systems initially established in Australia,Canada and other countries,played a very important role in prevention and control of animal diseases.Based on comparing the animal health systems of Australia with the veterinary medical system in China,some strategies was obtained for establishing a more reasonable official veterinary system and animal health system in China,thus speeding up the integration process of veterinary and human medical public health system.