Purpose: This study aimed to evaluate the safety and efficacy of gemcitabine and cisplatin (GP) regimen in combination with immune checkpoint inhibitor sintilimab as neoadjuvant therapy for muscle-invasive bladder cancer (MIBC) patients and the feasibility of the following selective bladder sparing surgery. Materials and Methods: Patients with histopathologically confirmed urothelial carcinoma without distant metastases (T2-4a, N ≤ 1, M0, American Joint Committee of Cancer 8th) and with adequate organ function will be enrolled. The therapeutic regimen was sintilimab 200 mg once on day 8, gemcitabine 1,000 mg/m2 and cisplatin 35 mg/m2 once on days 1 and 8, every 21 days for four cycles. The primary endpoint was pathologic complete response (pCR, pT0N0) rate. The secondary end points were ypT < 2 rate, R0 resection rate, event-free survival, and safety. Results: From May 4, 2020, to May 20, 2023, 55 patients were enrolled. Forty-six patients were evaluated for efficacy. Among the 42 patients who underwent surgery, 16 patients (38.0%) achieved pCR. Thirty-three patients (78.6%) achieved pT < 2. With a median follow-up of 15.7 months, the 1-year event-free survival was 91.3%. Notwithstanding the poor pathological baseline characteristic of a high T3-T4a proportion (39.1%), a promising bladder preservation (including 22 patients transurethral resection of bladder tumor, 5 patients partial cystectomy, and 4 surveillances) rate was achieved (67.4%). The most common grade ≥ 3 treatment-related adverse events was neutropenia (n=15, 27.3%), which was related to chemotherapy. There were no grade 3 immune-related adverse events. Conclusion Neoadjuvant GP plus sintilimab is a promising regimen for MIBC patients, with relatively high pT < 2 rate and triggering the emerging roles for the multi-disciplinary team decision-making for bladder sparing surgery.

Objective:To develop a novel fibroblast activation protein (FAP) cyclic peptide imaging agent, Al 18F-FAP-NOX, evaluate its in vitro and in vivo properties, and explore its feasibility of PET/CT imaging in tumors with FAP positive expression. Methods:Al 18F-FAP-NOX was manually synthesized. The in vitro stability of Al 18F-FAP-NOX was determined using radio high performance liquid chromatography (HPLC). The lipid water partition coefficient log P, in vitro cell uptake experiments, microPET/CT imaging and biodistribution in 293T-FAP tumor-bearing mice were conducted to preliminarily evaluate the pharmacokinetics and biological efficacy of Al 18F-FAP-NOX. Afterwards, a patient (male, 65 years old) with lung cancer underwent Al 18F-FAP-NOX PET/CT imaging. Results:Al 18F-FAP-NOX was successfully synthesized with a yield of (26.28±2.31)% without attenuation correction ( n=4), and the radiochemical purity was more than 95%. Al 18F-FAP-NOX exhibited good stability and hydrophilicity (log P=-3.02±0.08, n=5). In cell assays, the uptake of Al 18F-FAP-NOX in HT1080-FAP cells reached the plateau phase at 15 min ((7.31±0.53) percentage activity of injection dose per million cells (%ID/mio cells)), exhibiting high cellular uptake. The uptake of Al 18F-FAP-NOX could be significantly inhibited by 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-FAP-2286. The microPET/CT results of 293T-FAP tumor-bearing mice in vivo showed that Al 18F-FAP-NOX was highly uptaken in FAP-positive tumor tissues (60 min: (12.47±1.66) percentage activity of injection dose per gram of tissue (%ID/g)), while the uptake was very low in FAP-negative tumors. The biodistribution results were similar to the microPET/CT imaging results of tumor-bearing mice. The human clinical imaging showed an abnormal increase in Al 18F-FAP-NOX uptake (SUV max 5.5) of the lung cancer lesions. Conclusions:A novel cyclic peptide radiopharmaceutical, Al 18F-FAP-NOX, demonstrates good stability and hydrophilicity. It can be quickly distributed to tumor tissue in vivo. The human clinical PET/CT imaging shows certain diagnostic ability of Al 18F-FAP-NOX for lung cancer lesions. It is a promising cyclic peptide agent for PET imaging.

Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.

Artificial intelligence (AI) has emerged as a transformative force in healthcare, with applications spanning diagnostics to drug development. However, its integration into drug regulation remains nascent, with varying degrees of adoption and implementation across different regulatory bodies worldwide. This review aims to provide a comprehensive overview of the current state of AI in drug regulation, encapsulating AI-related policies, initiatives, and its practical application in regulatory agencies globally. It further discusses the challenges and future prospects of AI in this field. The findings reveal that numerous agencies have launched action plans and initiatives to incorporate AI, aiming to streamline regulatory processes and enhance data-driven regulatory decision-making. Moreover, AI's deployment in safety surveillance, workflow optimization, and regulatory science research is expanding, highlighting its increasing impact on drug regulation. Nonetheless, key challenges persist, such as data quality and reliability, technical limitations, talent shortage and the absence of standards. The review concludes that interdisciplinary collaboration is crucial to harness AI's full potential in drug regulation and overcoming its current limitations. In the future, AI may become a pivotal catalyst in drug regulation, promising a new era of enhanced scrutiny, efficiency, and innovation that will benefit public health on a global scale.

Objective:To develop a novel fibroblast activation protein (FAP) cyclic peptide imaging agent, Al 18F-FAP-NOX, evaluate its in vitro and in vivo properties, and explore its feasibility of PET/CT imaging in tumors with FAP positive expression. Methods:Al 18F-FAP-NOX was manually synthesized. The in vitro stability of Al 18F-FAP-NOX was determined using radio high performance liquid chromatography (HPLC). The lipid water partition coefficient log P, in vitro cell uptake experiments, microPET/CT imaging and biodistribution in 293T-FAP tumor-bearing mice were conducted to preliminarily evaluate the pharmacokinetics and biological efficacy of Al 18F-FAP-NOX. Afterwards, a patient (male, 65 years old) with lung cancer underwent Al 18F-FAP-NOX PET/CT imaging. Results:Al 18F-FAP-NOX was successfully synthesized with a yield of (26.28±2.31)% without attenuation correction ( n=4), and the radiochemical purity was more than 95%. Al 18F-FAP-NOX exhibited good stability and hydrophilicity (log P=-3.02±0.08, n=5). In cell assays, the uptake of Al 18F-FAP-NOX in HT1080-FAP cells reached the plateau phase at 15 min ((7.31±0.53) percentage activity of injection dose per million cells (%ID/mio cells)), exhibiting high cellular uptake. The uptake of Al 18F-FAP-NOX could be significantly inhibited by 1, 4, 7, 10-tetraazacyclododecane-1, 4, 7, 10-tetraacetic acid (DOTA)-FAP-2286. The microPET/CT results of 293T-FAP tumor-bearing mice in vivo showed that Al 18F-FAP-NOX was highly uptaken in FAP-positive tumor tissues (60 min: (12.47±1.66) percentage activity of injection dose per gram of tissue (%ID/g)), while the uptake was very low in FAP-negative tumors. The biodistribution results were similar to the microPET/CT imaging results of tumor-bearing mice. The human clinical imaging showed an abnormal increase in Al 18F-FAP-NOX uptake (SUV max 5.5) of the lung cancer lesions. Conclusions:A novel cyclic peptide radiopharmaceutical, Al 18F-FAP-NOX, demonstrates good stability and hydrophilicity. It can be quickly distributed to tumor tissue in vivo. The human clinical PET/CT imaging shows certain diagnostic ability of Al 18F-FAP-NOX for lung cancer lesions. It is a promising cyclic peptide agent for PET imaging.

Objective:To systematically evaluate the safety and efficacy of the novel fibroblast activation protein (FAP)-targeted tracer 64Cu-FAP inhibitor (FAPI)-XT117 in patients with malignant solid tumors, and to compare with 18F-FDG. Methods:This self-controlled study was conducted on fifteen patients (8 males, 7 females; age (60 ±9) years) with malignant solid tumors from the First Affiliated Hospital of Guangzhou Medical University between July 2023 and December 2023. Each subject underwent 64Cu-FAPI-XT117 PET/CT at 30, 60, and 120min post-injection and was assigned to three dose cohorts (111MBq, 148MBq, and 185MBq; 5 patients in each cohort), and safety assessments were conducted within 24h after injection. In addition, all patients underwent 18F-FDG PET/CT at 60min post-injection. Time-activity curves were generated for 64Cu-FAPI-XT117, and the dosimetry was calculated. Image quality was evaluated using a 5-point Likert scale, and the optimal injected activity and imaging time point were determined. The paired t test was used to compare differences of the lesion detection count and SUV max between 64Cu-FAPI-XT117 and 18F-FDG PET/CT. Results:64Cu-FAPI-XT117 was well tolerated, with no adverse events reported. Time-activity curves of 68Ga-FAPI-XT117 revealed prominent uptake in the uterus, while the background activity in other organs remained low, with the whole-body effective dose of (0.0084±0.0021)mSv/MBq. The optimal imaging time point for 64Cu-FAPI-XT117 PET/CT was 60min post-injection, with an optimal administered activity of 111MBq. Compared with 18F-FDG, 64Cu-FAPI-XT117 demonstrated significantly higher uptake and more lesions in lymph-node metastases (SUV max: 8.6±3.8 vs 15.3±6.8, t=2.33, P=0.048; number of lesions: 8.3±5.4 vs 15.0±6.4; t=4.21, P=0.003) and distant metastases (SUV max: 11.8±3.7 vs 20.9±7.2, t=3.66, P=0.022; number of lesions: 7.0±3.2 vs 12.4±3.7, t=2.86, P=0.046). Conclusions:64Cu-FAPI-XT117 PET/CT is well tolerated in patients with solid tumors, with a controllable radiation risk. Moreover, it outperforms 18F-FDG PET/CT in the assessment of metastases.

Purpose To investigate the effect of shortening the acquisition time of 18F-D6-AV133 PET/CT on image quality and diagnostic efficacy in Parkinson's disease.Materials and Methods A total of 51 participants(27 of Parkinson's disease,24 of healthy-controls)from the First Affiliated Hospital of Guangzhou Medical University from October 2021 to June 2022 were retrospectively selected.Images were obtained after the injection of the tracer 18F-D6-AV133(371.04±16.30)MBq for 60 min,with collection times of 10 min.Four sets of images were reconstructed using CT attenuation correction with acquisition times of 3,5,7 and 10 min.Semi-quantitative analysis was performed on the PET images,calculating the striatum-to-occipital lobe standardized uptake value ratio(SUVR).Two physicians independently conducted qualitative evaluations for each image group.The differences of SUVR and visual score results among four sets of images were performed.The optimal critical value of SUVR was obtained by analyzing the receiver operating characteristic curve of the subjects.Results The visual analysis of image quality had a strong consistency between the two doctors(ICC=0.853,P<0.001).The images with acquisition time of 5 min could reach the common quality level in clinical work,accounting for 78.4%(40/51).The semi-quantitative results of image quality showed that there was no significant difference between SUVR and diagnostic efficiency obtained by acquisition time 5 min and 10 min(Z=1.821,P=0.069),and the best critical value of the two groups was equal to 3.Therefore,properly shortening the acquisition time had no effect on the diagnosis of Parkinson's disease.Conclusion With the development and advancement of technical equipment,PET image quality is gradually improving and the scanning time is also gradually shortening.The acquisition time for 18F-D6-AV133 can be shortened from the conventional 10 min to 5 min.

Carotid atherosclerotic plaque is the main cause of ischemic stroke. In recent years, with the continuous innovation of novel imaging technologies, numerous classification standards for carotid plaques provide more powerful evidence for the features of carotid plaques and perioperative vascular assessment, as well as the reference for surgeons in choosing therapeutic decisions. Ultrasound is the preferred non-invasive and convenient screening tool for carotid stenosis. Invasive examinations such as CT angiography and magnetic resonance angiography are suitable for carotid stenosis patients to determine the plaque composition and stability, which can guide surgical decision-making and help to prevent serious cardiovascular and cerebrovascular adverse events. Advances in the treatment of carotid artery stenosis have focused on the improvement and innovation of vascular interventional devices and surgical procedures, including double-layer stents, coated stents and transcarotid artery revascularization. As technology continues to evolve, molecular imaging and more minimally invasive screening as well as therapies will be the way forward.

Objective To explore the mechanism by which Sestrin2(SESN2)regulates autophagy activity of chondrocytes by mediating mammalian rapamycin target protein complex 1(mTORC1)signaling pathway.Methods The normal chondrocytes were treated with interleukin-1 β(IL-1β)to establish an osteoarthritis(OA)chondrocyte model,which was divided into the control group and the IL-1 β-treated group.Real-time quantitative PCR(qPCR)and Western blot were used to detect the expression levels of matrix metalloproteinase 13(MMP13),type Ⅱ collagen(COL2A1)and SESN2 in the two groups.The cell models of the chondrocyte overexpression SESN2 group and knockdown SESN2 group were obtained via cell transfection technology,and the expression levels of SESN2 in each group were detected by qPCR while those of SESN2,MMP13,COL2A1,mTORC1 pathway-related proteins and autophagy-related proteins in each group were detected by Western blot.The effects of SESN2 on cell proliferation and migration were detected by CCK-8 and cell scratch assay.Results(1)The expression level of MMP13 in the IL-1 β-treated group was significantly up-regulated,while the expression levels of COL2A1 and SESN2 were significantly decreased.(2)Compared with the control group,the expressions of p-mTORC1,ribosomal protein S6 kinase 1(S6K1),and MMP13 protein in OA chondrocytes in the overexpression group were significantly down-regulated,while the expressions of adenosine 5'-monophosphate(AMP)-activated protein kinase(AMPK)and chondroprotective gene COL2A1 were significantly increased,and the expression level of Beclin-1 and the ratio of microtubule associated protein 1 light chain 3-Ⅱ(LC3-Ⅱ)/(LC3-Ⅰ)were increased.Meanwhile,overexpression of SESN2 could up-regulate the proliferation and migration of chondrocytes,but the results were opposite after knockdown of SESN2.Conclusion SESN2 can enhance autophagy,proliferation and migration of chondrocytes by inhibiting mTORC1 pathway,which has provided data for revealing the pathogenesis of OA and exploring new therapeutic methods.

Carotid atherosclerotic plaque is the main cause of ischemic stroke. In recent years, with the continuous innovation of novel imaging technologies, numerous classification standards for carotid plaques provide more powerful evidence for the features of carotid plaques and perioperative vascular assessment, as well as the reference for surgeons in choosing therapeutic decisions. Ultrasound is the preferred non-invasive and convenient screening tool for carotid stenosis. Invasive examinations such as CT angiography and magnetic resonance angiography are suitable for carotid stenosis patients to determine the plaque composition and stability, which can guide surgical decision-making and help to prevent serious cardiovascular and cerebrovascular adverse events. Advances in the treatment of carotid artery stenosis have focused on the improvement and innovation of vascular interventional devices and surgical procedures, including double-layer stents, coated stents and transcarotid artery revascularization. As technology continues to evolve, molecular imaging and more minimally invasive screening as well as therapies will be the way forward.