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Despite advances in immunotherapy for the treatment of cancers,not all patients can benefit from programmed cell death ligand 1(PD-L1)immune checkpoint blockade therapy.Anti-PD-L1 therapeutic effects reportedly correlate with the PD-L1 expression level;hence,accurate detection of PD-L1 expression can guide immunotherapy to achieve better therapeutic effects.Therefore,based on the high affinity antibody Nb109,a new site-specifically radiolabeled tracer,68Ga-NODA-cysteine,aspartic acid,and valine(CDV)-Nb109,was designed and synthesized to accurately monitor PD-L1 expression.The tracer 68Ga-NODA-CDV-Nb109 was obtained using a site-specific conjugation strategy with a radiochemical yield of about 95％and radiochemical purity of 97％.It showed high affinity for PD-L1 with a dissociation constant of 12.34±1.65 nM.Both the cell uptake assay and positron emission tomography(PET)imaging revealed higher tracer uptake in PD-L1-positive A375-hPD-L1 and U87 tumor cells than in PD-L1-negative A375 tumor cells.Meanwhile,dynamic PET imaging of a NC1-H1299 xenograft indicated that doxorubicin could upregulate PD-L1 expression,allowing timely interventional immunotherapy.In conclusion,this tracer could sensitively and dynamically monitor changes in PD-L1 expression levels in different cancers and help screen patients who can benefit from anti-PD-L1 immunotherapy.
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Objective:To synthesize a novel site-specifically labelled probe 68Ga-1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-Cys-Asp-Val (CDV)-Nb109 and explore its potential for detection of the programmed cell death ligand 1 (PD-L1) expression level in different tumors. Methods:Firstly, CDV was inserted into the tail of the sequence of Nb109 by genetic engineering. Then the precursor DOTA-CDV-Nb109 was prepared by mixing the maleimide-DOTA and the single-domain antibody CDV-Nb109 (amount of substance ratio 1∶1) via the maleimide-cysteine site-specific coupling strategy. Subsequently, the DOTA-CDV-Nb109 was labeled with 68Ga and purified by PD-10 column. Human melanoma A375, human PD-L1 transfected melanoma A375-hPD-L1 and human glioma U87 tumor-bearing mice models were established, and the diagnostic value of 68Ga-DOTA-CDV-Nb109 was evaluated by stability assay, cellular uptake, and microPET imaging. One-way analysis of variance and the least significant difference t test were used to analyze the data. Results:The probe 68Ga-DOTA-CDV-Nb109 was obtained with the radiochemical yield of (69.79±4.69)%, radiochemical purity more than 97%, and molar activity of (12.85±1.51) GBq/μmol. 68Ga-DOTA-CDV-Nb109 had strong binding affinity for A375-hPD-L1 with the dissociation constant ( Kd) of (66.43±17.89) nmol/L. The uptake of 68Ga-DOTA-CDV-Nb109 in A375-hPD-L1 and U87 cells were (3.17±0.15) percentage of the added radioactivity dose (%AD) and (2.08±0.03) %AD respectively, which were significantly higher than that in A375 cells ((1.21±0.14) %AD; F=82.87, t values: 15.23, 9.98, P values: <0.001, 0.003). The tumor uptake of the probe in A375-hPD-L1 ((5.21±0.35) percentage of injected dose per ml (%ID/ml)) and U87 tumor-bearing mice ((3.44±0.69) %ID/ml) were significantly higher than that in A375 tumor-bearing mice ((2.17±0.36) %ID/ml; F=249.72, t values: 35.70, 3.43, both P<0.001). Conclusion:The site-specifically labelled probe 68Ga-DOTA-CDV-Nb109, which can non-invasively and dynamically monitor the change of PD-L1 expression level in different tumors and help screen patients who can benefit from PD-L1 immune checkpoint blocking therapy, is successfully synthesized with high radiochemical purity.
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Objective To explore the effectiveness of 12-week exercises with different intensities on cardiorespiratory fitness(CRF)of rats,so as to provide theoretical evidences for evaluating effective exercise loads.Methods Forty male Wistar rats were randomly divided into a low intensity group(50％ VO2max),a moderate intensity group(65％VO2max),a high intensity group(80％VO2max)and a sedentary group,each of 10.All rats were measured the VO2max after three-day adaptive training,then they were repeated the VO2max test every two weeks on the non-training days and the load of the next two weeks was adjusted according to the test result.The treadmill speed was controlled to maintain the specific exercise intensity of each group in the training period.The rats in the exercise groups were trained 5 days per week and 60 minutes per day.After 12 weeks of exercise intervention,the ultrasonic cardiogram tests were conducted.Results After 12 weeks of exercise,compared with the sedentary group,the average weight of the low and high intensity groups decreased significantly(P＜0.05,P＜0.01).After the 12-week exercise intervention,the average VO2max of the three exercise groups were significantly higher than the sedentary group (P＜0.01).The average CRF of the moderate and high intensity group improved faster,with their peak value at the 6th and 8th week respectively.However,in the low intensity group significant improvement in the average CRF was observed from the 10th week,with the peak value appearing at the 12th week.The average left ventricular internal dimension systole of the high intensity group was lower than the low intensity group(P＜0.05),while the ejection fraction and left ventricular shortening fraction increased significantly (P＜0.05).Conclusions Exercises with different intensity can improve the CRF.However,compared with moderate and high intensity exercise,it requires longer time to improve CRF with low intensity exercise.Only exercise with 80％VO2max can significantly improve the cardiac pumping function.
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Objective To investigate the effect of acute exercises of different intensities on the "browning" of epididymal white adipose tissue(WAT) in rats.Methods Thirty Sprague-Dawley male rats were randomly divided into a control group(C,n=6) and an exercises group(E,n=24).Rats in group E were further randomly divided into a moderate intensity exercise (EM,n=12,V=15 m/min) group and a high intensity intermittent exercise(EH,n=12,V=35 m/min,6min's exercises followed by 5 min's rest,repeating 3 times) group.Right after and 6 hours after the acute exercises,the epididymal WAT was taken,and the fibronectin type Ⅲ domain-containing 5 protein(FNDC5) and the uncoupling protein 1(UCP-1) mRNA were detected using RT-qPCR,while the level of FNDC5 and UCP-1 protein was evaluated using Western Blotting.Results Right after the acute exercises,compared with group C,the level of FNDC5 mRNA in group EH increased significantly (P＜0.01),while that of UCP-1 mRNA in group E decreased immediately(P＜0.05) but increased significantly six hours later(P＜0.05).Compared with group C,the level of FNDC5 in groups EM and EH tended to rise,and that of group EM increased significantly(P＜0.05).Compared with group C,the level of UCP-1 in group EM and EH had the tendency to rise,and it increased significantly immediately after exercises in group EH (P＜0.05).Conclusion The acute exercise at different intensities can promote the level of FNDC5 and UCP-1 in epididymal white adipose tissue,"browning" and heat production from fat issues.The level of UCP-1 mRNA increased significantly at 6 hours after exercises,while that of FNDC5 mRNA increased most immediately after the high-intensity intermittent exercises.
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Objective To explore the optimal exercise way of improving the risk indicators of electrocardiogram (ECG) during exercise.Methods Twenty-four healthy male subjects aged between 40 and 49 years old were divided randomly into a control group (n=9),a low amount exercise group of 1200 kcal/wk (n=7) and a high amount exercise group of 2000 kcal/wk (n=8).The intensity of the exercise groups was 65％～ 80％VO2max training in the standard 400 m track for 12 weeks.The accelerometer and polar watch were worn to monitor the exercise process.During the exercise,the exercise amount was controlled using the distance and duration while the intensity was controlled using target heart rate.The subjects took part in the graded exercise test before and after the exercise intervention.Twelve lead electrocardiograms were used to measure the indicators of ST segment depression and corrected QT interval dispersion (QTcd) during the exercise.Results The exercise intervention did not result in significant change in ST segment depression,while the QTcd indicator in both the exercise groups decreased significantly after the intervention (P＜0.05).Moreover,the decrease of QTcd indicator in the low amount exercise group was significantly higher than that of the control group (P＜0.05),while the decrease of QTcd indicator in high volume group was higher than that of the control group (P＜0.01).No significant differences were found in the ST segment depression among the 3 different groups.Conclusion The Twelve-weeks exercise interventions with intensity of 65％ ～ 80％ VO2max and exercise amount of 1200 kcal/wk and 2000 kcal/wk have no effect on the ST segment depression during the exercise.However,they can result in significant decrease in the QTcd of ECG during exercise,reducing the risk of exercise-induced myocardial ischemia.
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Objective To observe the effects of high fat diet and 6?week voluntary wheel running on the structure of hypothalamus, pituitary and testis and sex hormone levels in pubertal male rats. Methods Forty 3?week?old male Spra?gue?Dawley rats were randomly divided into following groups: the control group fed with normal diet (C), training group fed with normal diet ( CE) , control group fed with high fat diet ( D) , and training group fed with high fat diet ( DE) , 10 rats in each group. The groups C and D were bred for 8 weeks freely, and the groups CE and DE were assigned to have vol?untary wheel running twice/d, 1 h/time, 5 d/w, for 6 weeks after a 2?week adaptive feeding. Eight weeks later, blood sample was collected to detect the serum T, E2 , FSH and LH, and the E2 and T of testis were also detected. The histology of hypothalamic, pituitary, and testis tissues was observed by light microscopy. Results ( l) Compared with the group C, the group D had significantly decreased levels of serum T and E2 and testicular T (P<0?05), and significantly increased serum E2, FSH and LH levels (P<0?05). In the group D, vacuolar lipid droplets were increased in the hypothalamus, e?osinophils and basophils were reduced in the pituitary, and the area of seminiferous tubules, percentage of sperm cells, and quantity of Leygid cells were significantly decreased in the testis. (2) Compared with the group D, the serum T and testic?ular T concentrations were increased, but the serum E2, FSH and LH were decreased significantly (P<0?05) in the group DE, and vacuolar lipid drops were increased in the hypothalamus, eosinophil cells were increased in the pituitary gland, and the area of seminiferous tubules was increased but not significantly in the testis. Conclusions 6?week voluntary wheel exercise can improve the high fat diet?induced abnormal secretion of sex hormones, but not effectively improve the histologi?cal changes in hypothalamus, pituitary gland and testis.
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Objective To observe the effects of different interventions on the body mass index (BMI) and body fat content in overweight and obese adolescents, with an attempt to design reasonable weight relief program.Methods Totally 67 overweight or obese adolescents from a middle school of Beijing were randomly divided into three groups: control group ( n = 16 ), diet intervention group ( n= 22), and combined interventions group ( n =29). The changes of BMI and body fat rate (BFR) were observed. Results BMI significantly decreased after interventions ( diet intervention group: P = 0. 000; combined interventions group: P = 0. 018 ); the change of BMI in diet intervention group was significantly larger than that in control group ( P = 0. 035 ). The trunk and body BFRs also significantly decreased after interventions (diet intervention group: P=0. 000, P = 0. 013; combined interventions group: P = 0. 000, P = 0. 000 ); the changes of trunk and body BFRs were significantly larger in combined interventions group than those in control group ( P = 0.005, P = 0. 003 ). Conclusion Diet intervention and combined interventions are both effective in achieving weight loss in adolescents, and combined interventions have superior effectiveness.
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Objective To explore the effects of diet and/or exercise intervention on oxidative stress of overweight or obese adolescents.Methods Thirty-one adolescents with normal body weight(normal control group)and 93 overweight or obese adolescents(average age(13.6 ±0.7)years; body mass index (BMI)22.4 to 34.1 kg/m2)were enrolled in this study.The overweight or obese participants were then randomly assigned to the diet group(group A),exercise group(group B),diet plus exercise group(group C),and non-intervention group(group D).Individualized caloric intake was carried out.One-hour afterschool exercise was performed once per day,4 days per week for 10 weeks.Changes of anthropometry,body composition,and metabolic biomarkers were determined.Results Compared to the normal control group,serum levels of fasting glucose,total cholesterol(TC),low-density lipoprotein cholesterol(LDL-C),and malondialdehyde(M DA)of the in overweight group were significant increased(all P ＜ 0.05),although the level of SOD was significant decreased(P ＜ 0.05).Serum MDA level was positively correlated with bodyweight,BMI,TC,and LDL-C(R values were 0.209,0.228,0.274,and 0.263,respectively ; all P ＜0.05),and serum SOD level was negatively correlated with bodyweight and BMI(R values were-0.334 and-0.362,respectively ; both P ＜ 0.05).Group A,B and C showed a significant decrease in BMI,waist circumference and body fat after the intervention(all P ＜ 0.05).The level of MDA was significantly decreased after the intervention in group A and B(both P ＜ 0.05); the levels of TC and LDL-C were significantly decreased in group B and C(both P ＜ 0.05).Conclusion:Oxidative stress could have existed in overweight adolescents even when their serum glucose and lipid profiles are at a normal level.Ten-week diet and/or exercise intervention may contribute to improved body weight control,lipid metabolism,and oxidative stress response in this population.