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 explore the infection status and clinical characteristics of human parvovirus B19 (HPV-B19) in patients with hematological disease. Methods A total of 94 patients with benign hematological disease, 128 patients with hematological malignancy, and 89 healthy individuals at Shanghai Eighth People’s Hospital from February 2019 to February 2020 were selected. The levels of specific IgM and nucleic acid of HPV-B19 in the plasma were detected using ELISA and PCR. The infection rates among the 3 groups and clinical characteristics between HPV-B19 positive and negative patients with hematological disease were compared. Results The positive rate of HPV-B19 IgM was 9.6% (9/94), the positive rate of nucleic acid was 11.7% (11/94), and the overall infection rate of HPV-B19 (IgM and/or nucleic acid positive) was 14.9% (14/94) in benign group of patients. The positive rate of HPV-B19 IgM was 18.0% (23/128), the positive rate of nucleic acid was 19.5% (25/128), and the overall infection rate of HPV-B19 was 26.6% (34/128) in malignant group of patients. The positive rate of HPV-B19 IgM was 1.1% (1/89), the positive rate of nucleic acid was 2.2% (2/89), and the overall infection rate of HPV-B19 was 2.2% (2/89) in healthy controls. The overall HPV-B19 infection rate in benign group of patients was higher than that in healthy controls (P＝0.006). The overall HPV-B19 infection rate was higher in malignant group of patients than that in benign group of patients (P＝0.037) and healthy controls (P＜0.001). In the benign group, the HPV-B19 infection rates in patients with pure red cell aplasia (PRCA), autoimmune hemolytic anemia (AIHA), immune thrombocytopenic purpura (ITP), and aplastic anemia (AA) were higher, with 44.4% (4/9), 27.3% (3/11), 25.0% (4/16), and 21.4% (3/14), respectively. In the malignant group, the HPV-B19 infection rates in patients with non-Hodgkin lymphoma (NHL) and chronic lymphocytic leukemia (CLL) were higher, with 42.9% (9/21) and 37.5% (6/16), respectively. The HPV-B19 positive patients in both hematological disease groups were older (P＜0.05). In patients with NHL, CLL or multiple myeloma (MM), HPV-B19 infection decreased the reticulocyte ratio (P＜0.05); in patients with NHL, acute myeloid leukemia (AML) or acute lymphoblastic leukemia (ALL), HPV-B19 infection prolonged bone marrow suppression time after chemotherapy (P＜0.05). Conclusions HPV-B19 infection rate in patients with hematological disease is elevated and HPV-B19 infection may influence the condition and treatment efficiency of these patients.

Objective:To evaluate the accuracy of the oral healthcare information provided by different large language models (LLM) to explore their feasibility and limitations in the application of oral auxiliary, treatment and health consultation.Methods:This study designed eight items comprising 47 questions in total related to the diagnosis and treatment of oral diseases [to assess the performance of LLM as an artificial intelligence (AI) medical assistant], and five items comprising 35 questions in total about oral health consultations (to assess the performance of LLM as a simulated doctor). These questions were answered individually by the five LLM models (Erine Bot, HuatuoGPT, Tongyi Qianwen, iFlytek Spark, ChatGPT). Two attending physicians with more than 5 years of experience independently rated the responses using the 3C criteria (correct, clear, concise), and the consistency between the raters was assessed using the Spearman rank correlation coefficient, and the Kruskal-Wallis test and Dunn post hoc test were used to assess the statistical differences between the models. Additionally, this study used 600 questions from the 2023 dental licensing examination to evaluate the time taken to answer, scores, and accuracy of each model.Results:As an AI medical assistant, LLM can assist doctors in diagnosis and treatment decision-making, with an inter-evaluator Spearman coefficient of 0.505 ( P<0.01). As a simulated doctor, LLM can carry out patient popularization, with an inter-evaluator Spearman coefficient of 0.533 ( P<0.01). The 3C scores of each model as an AI medical assistant and a simulated doctor were respectively: 2.00 (1.00, 3.00) and 2.00 (2.00, 3.00) points of Erine Bot, 1.00 (1.00, 2.00) and 2.00 (1.00, 2.00) points of HuatuoGPT, 2.00 (1.00, 2.00) and 2.00 (1.00, 3.00) points of Tongyi Qianwen, 2.00 (1.00, 2.00) and 2.00 (1.75, 2.25) points of iFlytek Spark, 3.00 (2.00, 3.00) and 3.00 (2.00, 3.00) points of ChatGPT (full score of 4 points). The Kruskal-Wallis test results showed that, as an AI medical assistant or a simulated doctor, there were statistically differences in the 3C scores among the five large language models (all P<0.001). The average score of the 5 LLMs on the dental licensing examination was 370.2, with an accuracy rate of 61.7% (370.2/600) and a time consumption of 94.6 min. Specifically, Erine Bot took 115 min, scored 363 points with an accuracy rate of 60.5% (363/600), HuatuoGPT took 224 min and scored 305 points with an accuracy rate of 50.8% (305/600), Tongyi Qianwen took 43 min, scored 438 points with an accuracy rate of 73.0% (438/600), iFlytek Spark took 32 min, scored 364 points with an accuracy rate of 60.7% (364/600), and ChatGPT took 59 min, scored 381 points with an accuracy rate of 63.5% (381/600). Conclusions:Based on the evaluation of LLM′s dual roles as an AI medical assistant and a simulated doctor, ChatGPT performes the best, with basically correct, clear and concise answers, followed by Erine Bot, Tongyi Qianwen and iFlytek Spark, with HuatuoGPT lagging behind significantly. In the dental licensing examination, all the 4 LLM, except for HuatuoGPT, reach the passing level, and the time consumpution for answering is significantly reduced compared to the 8 h required for the exam regulations in all of the five models. LLM has the feasibility of application in oral auxiliary, treatment and health consultation, and it can help both doctors and patients obtain medical information quickly. Howere, their outputs carry a risk of errors (since the 3C scoring results do not reach the full marks), so prudent judgment should be exercised when using them.

OBJECTIVE To explore the mechanism of Qingwen Baidu Drink in treating sepsis-induced lung injury.METHODS One hundred C57BL/6 mice were randomly divided into blank group,model group,Qingwen Baidu Drink low-dose group,Qingwen Baidu Drink medium-dose group,and Qingwen Baidu Drink high-dose group,with 20 mice in each group.HE staining was used to examine the pathological changes of lung tissues.ELISA was used to detect the expression levels of serum interleukin-1β(IL-1β),tumor necrosis factor-α(TNF-α),chemokine ligand 10(CXCL10)and plasma coagulation factor Ⅲ(F3).qPCR was used to detect the mRNA expression levels of monocyte chemoattractant protein-1(MCP-1),cyclooxygenase-2(COX-2)and interferon-γ(IFN-γ)in lung tissues.The number of platelets(PLT)in plasma was analyzed by routine blood analysis instrument.Immunofluorescence a-nalysis was used to detect vascular endothelial cadherin(VE-cadherin),endothelial adhesion junction marker occludin 5(CLDN5)and pericyte marker neuronal collagen antigen 2(NG2)in alveolar capillary endothelial cells.Western blot was used to detect the pro-tein expression levels of cysteine-containing aspartate proteinase 11(Caspase11),GSDMD and GSDMD-N in mouse lung tissues.RESULTS Compared with the blank group,the lung tissue of the mice in the model group showed obvious pathological dam-age.The levels of serum IL-1β,TNF-α,and CXCL10 and the mRNA expression levels of MCP-1,COX-2,and IFN-γ in lung tis-sue were significantly increased(P<0.01),and the number of PLT and the content of F3 in plasma were significantly decreased(P<0.01).The fluorescence expression of VE-cadherin,CLDN5,and NG2 proteins in lung tissue was significantly enhanced(P<0.01),while the expression of Caspase11 and GSDMD-N proteins was increased(P<0.01).Compared with the model group,the pathological damage of the lung tissue of the mice in all doses of Qingwen Baidu Drink groups was alleviated,the levels of serum IL-1β,TNF-α,and CXCL10 and the mRNA expression levels of MCP-1,COX-2,and IFN-γ in lung tissue were significantly decreased(P<0.05,P<0.01),and the number of PLT and the content of F3 in plasma were increased(P<0.05,P<0.01);the fluorescence expression of VE-cadherin,CLDN5,and NG2 proteins in lung tissues was weakened(P<0.05,P<0.01),and the expression of Caspase11 and GSDMD-N/GSDMD proteins was reduced(P<0.05,P<0.01).CONCLUSION Qingwen Baidu Drink can inhibit the activation of GSDMD-N and Caspase11,reduce the release of inflammatory factors,decrease blood loss and damage to vascular barrier function,and thus improve the lung injury caused by sepsis.

This review aimed to provide a comprehensive analysis of the etiology, epidemiology, pathology, and conventional treatment of heterotopic ossification (HO), especially emerging potential therapies. HO is the process of ectopic bone formation at non-skeletal sites. HO can be subdivided into two major forms, acquired and hereditary, with acquired HO predominating. Hereditary HO is a rare and life-threatening genetic disorder, but both acquired and hereditary form can cause severe complications, such as peripheral nerve entrapment, pressure ulcers, and disability if joint ankylosis develops, which heavily contributes to a reduced quality of life. Modalities have been proposed to treat HO, but none have emerged as the gold standard. Surgical excision remains the only effective modality; however, the optimal timing is controversial and may cause HO recurrence. Recently, potential therapeutic strategies have emerged that focus on the signaling pathways involved in HO, and small molecule inhibitors have been shown to be promising. Moreover, additional specific targets, such as small interfering RNAs (siRNAs) and non-coding RNAs, could be used to effectively block HO or develop combinatorial therapies for HO.
Humans ; Ossification, Heterotopic/genetics*

Objective:To investigate the effect of cytoskeleton-associated protein 4 (CKAP4) gene knockout on maxillary expansion osteogenesis and its regulatory mechanism on the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSC).Methods:Nineteen wild type (WT) and nineteen CKAP4 gene knockout (Ckap4 -/-) mice aged 6-8 weeks were selected to establish a mouse model of rapid maxillary expansion. Samples were taken on the 7th and 14th day after the operation. Micro-CT and HE staining were used to evaluate bone regeneration. Tissue proteins in the modeled area were collected, and Western blotting analysis (WB) was used to detect the protein expression levels of alkaline phosphatase (ALP), Runt-related transcription factor 2 (RUNX2), and osteocalcin (OCN). BMSC were isolated from WT and Ckap4 -/- mice. The expression of surface markers CD29, Sca-1, CD44, CD45, CD34, and CD11b was detected by flow cytometry, and cell proliferation ability was detected by 5-ethynyl-2'-deoxyuridine (EdU). After 7 days of osteogenic induction, real-time fluorescence quantitative PCR (RT-qPCR) and WB were used to detect the expression levels of RUXN2, ALP, OCN, protein kinase B (AKT), and phosphorylated protein kinase B (p-AKT). After 21 days, alizarin red staining and cetyl pyridine chloride quantification were used to detect the differences in mineralized nodule formation in each group. In CKAP4 gene knockout BMSC, the small-molecule AKT agonist sc79 (4 μg/ml) was added as the intervention group (Ckap4 -/- +sc79), and dimethyl sulfoxide (DMSO) treatment was used as the control group (Ckap4 -/- +DMSO). After osteogenic induction, RT-qPCR, WB, and alizarin red staining were used to compare the osteogenic differentiation differences between the two groups of cells. Results:The micro-CT results showed that at 7 days and 14 days after surgery, the new bone volume in the Ckap4 -/- group [(0.070±0.010) and (0.146±0.019) mm 3] was significantly lower than that in the WT group [(0.094±0.006) and (0.196±0.013) mm 3] (both P<0.01). HE-stained histological sections showed that the area of new bone tissue in the Ckap4 -/- group at 7 days and 14 days after surgery [(0.101±0.008) and (0.158±0.010) mm 2] was also significantly lower than that in the WT group [(0.116±0.005) and (0.183±0.008) mm 2] (both P<0.05). WB was used to detect the tissue proteins in the maxillary modeling area of mice in the two groups 7 days after surgery. The results showed that the expression levels of ALP, RUNX2 and OCN in the Ckap4 -/- group were significantly lower than those in the WT group. BMSC from wild-type mice and CKAP4 knockout mice were both positively expressed for CD29, CD44, and Sca-1, and basically not expressed for CD45, CD34, and CD11b. EdU assay showed that there was no significant difference in the proliferation ability of cells in the two groups. After 21 days of osteogenic induction of BMSC, alizarin red staining results showed that the number of mineralized nodules in the Ckap4 -/- group was significantly less than that in the WT group. After adding sc79, the number of mineralized nodules increased significantly, which was consistent with the results of cetyl pyridine chloride quantification. After 7 days of osteogenic induction, It was found that the expression levels of ALP, RUNX2, and OCN in the CKAP4 -/-group (0.751±0.066, 0.484±0.040, 0.679±0.063) were significantly lower than those in the WT group (1.000±0.113, 1.000±0.081, 1.000±0.113) (all P<0.001). The results of WB were consistent with those of RT-qPCR. At the same time, the WB results showed that the level of p-AKT protein in the CKAP4 -/-group (0.518±0.114) was significantly lower than that in the WT group (1.000±0.234) ( P<0.05). After treatment with sc79 for 7 days of osteogenic induction, RT-qPCR was used to detect the gene expression levels of ALP, RUNX2, and OCN. The results showed that the expression levels in the CKAP4 -/-+sc79 group (2.755±0.353, 4.800±0.990, 2.524±0.137) were significantly higher than those in the CKAP4 -/-+DMSO group (1.000±0.078, 1.000±0.247, 1.000±0.175) (all P<0.001). Conclusions:CKAP4 knockout inhibits the osteogenic differentiation of BMSC by reducing the activity of the PI3K/AKT signaling pathway, thereby suppressing osteogenesis in maxillary expansion.

BACKGROUND: Neoadjuvant therapeutic strategies play a pivotal role in the comprehensive treatment of non-small cell lung cancer (NSCLC). However, lung squamous cell carcinoma (SCC) generally exhibits a more favorable response to neoadjuvant therapy compared with lung adenocarcinoma (ADC). The aim of this study is to elucidate how baseline cancer-associated fibroblasts (CAFs) and tumor-associated endothelial cells (TAECs) influence the differential therapeutic outcomes of neoadjuvant treatment in SCC versus ADC. METHODS: We retrospectively collected pretreatment biopsy samples from 104 patients with stage II-III NSCLC who underwent neoadjuvant chemotherapy (NAC) or neoadjuvant chemoimmunotherapy (NAIC) at Shandong Cancer Hospital between January 1, 2018 and December 31, 2023. Tissue microarrays were constructed using an automated arrayer, and multiplex immunofluorescence staining (α-SMA/CD31/CK/DAPI) was performed to identify CAFs (α-SMA+/CK-) and TAECs (CD31+/CK-). Quantitative analyses included CAFs and TAECs densities, the nearest neighbor distance (NND) between CAFs and TAECs, and their spatial proximity (30 μm). Differences in major pathological response (MPR) between groups, defined as residual viable tumor cells ≤10% in resected specimens after neoadjuvant therapy, were assessed using the χ² test. The Mann-Whitney U test was applied to analyze intergroup differences in quantitative indicators, and receiver operating characteristic (ROC) curve analysis was conducted to evaluate the predictive performance of immune-related markers for MPR in the NAIC cohort. RESULTS: Among the 104 NSCLC patients who received neoadjuvant therapy, 35 underwent NAIC and 69 received NAC. Overall, patients with SCC were more likely to achieve MPR compared with those with ADC (50.0% vs 22.4%, P=0.006). This trend persisted in the NAIC subgroup (72.7% vs 30.8%, P=0.038), whereas no significant difference in MPR rates was observed between SCC and ADC in the NAC subgroup. At baseline, prior to NAIC or NAC, programmed cell death ligand 1 (PD-L1)/programmed cell death 1 (PD-1) expression, CAFs and TAECs densities, CAFs-TAECs NND, and CAFs-TAECs proximity (30 μm) showed no significant differences between SCC and ADC. In patients with SCC receiving NAIC, baseline PD-L1/PD-1 expression, CAFs density, and TAECs density showed not significant differences between MPR and NMPR groups. However, the CAFs-TAECs distance was significantly greater in the MPR group (NND: 31.2 vs 24.7 μm, P=0.038), and the number of TAECs within 30 μm of CAFs was significantly lower (proximity: 1.1 vs 3.6, P=0.038). Univariate Cox regression analysis indicated that low TAECs density was associated with MPR following NAIC (OR=36.00, 95%CI: 2.68-1486.88, P=0.019). Furthermore, ROC analysis demonstrated that baseline CAFs-TAECs NND and proximity (30 μm) exhibited strong predictive performance for MPR in SCC patients treated with NAIC, with an area under the curve (AUC) of 0.893, sensitivity of 0.857, and specificity of 1.000. CONCLUSIONS CAFs are more spatially distant from TAECs and more prone to MPR after NAIC in SCC, which may be related to the reduced interaction of CAFs with TAECs and reduced tumor-associated angiogenesis.
Humans ; Lung Neoplasms/therapy* ; Neoadjuvant Therapy ; Male ; Female ; Middle Aged ; Retrospective Studies ; Endothelial Cells/drug effects* ; Aged ; Cancer-Associated Fibroblasts/drug effects* ; Immunotherapy ; Carcinoma, Squamous Cell/drug therapy* ; Carcinoma, Non-Small-Cell Lung/drug therapy* ; Adult

Objective:To systematically evaluate the efficacy, patient-reported outcomes (PROs) and safety of hyaluronic acid (HA) fillers and collagen stimulators (PCL/PLLA) for various facial aesthetic indications.Methods:This study focused on facial fillers approved and widely used in China, including HA fillers such as Juvéderm?, Restylane?, Belotero?, Fillmed?, and PCL/PLLA such as Ellansé?, L?viselle?, and CureWhite?. A systematic literature search was conducted across both English and Chinese databases, including PubMed, Cochrane Library, Embase, CNKI, and Wanfang Data, covering the period from database inception to August 24, 2023, to identify randomized controlled trials (RCTs). The characteristics and outcomes of the included RCTs were summarized and analyzed, including efficacy indicators by injection site, patient satisfaction, and safety profiles. Network meta-analysis (NMA) was performed using R software to compare efficacy outcomes, including the 6-month improvement response rate for nasolabial folds (NLF) and the global aesthetic improvement scale (GAIS).Results:A total of 38 articles were included. Among them, Juvéderm? was most frequently used as the treatment group (17 out of 38 articles), while Restylane? was the most common comparator (17 out of 38 articles), particularly in studies involving NLF injections (15 out of 16 articles). For collagen stimulators, only 2 studies on Ellansé? were included, both focusing solely on NLF treatment. Quality assessment showed that 34 studies were of medium to high quality, with Juvéderm? accounting for the majority of high-quality studies (11 articles). Based on injection sites, NLF was the most studied area (16 articles), followed by the midface (8 articles), and the remaining 14 articles covered other regions including lips, nose, chin, and infraorbital area. In the NLF region, the 6-month improvement response rate assessed by blinded investigators showed that Juvéderm? showed better outcomes than Restylane? ( RR=1.07, 95% CI: 0.89-1.32), while Belotero? was slightly inferior to Restylane? ( RR=0.97, 95% CI: 0.65-1.44), although the differences were not statistically significant. Subject-reported outcomes showed consistent trends with investigator assessments. For 6-month GAIS improvement, Juvéderm? and Restylane? showed comparable result within the HA filler category ( RR=1.01, 95% CI: 0.71-1.43). The collagen stimulator Ellansé? demonstrated numerically higher values than HA fillers ( RR=1.32, 95% CI: 0.86-2.08). However, none of these differences reached statistical significance. In midface treatments, Juvéderm? had more long-term evidence, with follow-up periods extending up to 24 months. Four studies reported numerically greater volume enhancement with Juvéderm? compared to Restylane?. For other facial areas, Juvéderm? had the most comprehensive clinical evidence, covering the widest range of injection sites. No relevant RCTs were available for collagen stimulators in these regions. Regarding patient satisfaction, 19 studies reported patient-reported outcomes, with Juvéderm? contributing 16 of them, and showing higher satisfaction in 6 head-to-head comparisons with Restylane?. In contrast, collagen stimulators currently lack such evidence. Safety result indicated that HA fillers were generally safe and well tolerated, while safety data for collagen stimulators remain limited due to insufficient high-quality evidence. Conclusion:Among the HA fillers, Juvéderm? has a large quantity and highest quality of clinical studies, and NMA result shows its superior efficacy in NLF. In comparison, the current evidence is still not sufficient to draw a clear conclusion for the PCL/PLLA due to a lack of adequate high-quality clinical evidence regarding its clinical efficacy, PROs, and safety.

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.