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The NMDA receptor GluN2B subunit is a target of interest in neuropsychiatric disorders but to date there is no selective radiotracer available to quantify its availability in vivo. Here we report direct comparisons in non-human primates of three GluN2B-targeting radioligands: (R)-[11C]NR2B-Me, (R)-[18F]OF-Me-NB1, and (S)-[18F]OF-NB1. Plasma free fraction, metabolism, tissue distribution and kinetics, and quantitative kinetic modeling methods and parameters were evaluated in two adult rhesus macaques. Free fraction in plasma was 11C]NR2B-Me and (R)-[18F]OF-Me-NB1 and higher for (S)-[18F]OF-NB1 (15%). All radiotracers showed good brain uptake and distribution throughout grey matter, with substantial (>68%) blockade across the brain by the GluN2B-targeting drug Co-101,244 (0.25 mg/kg), including in the cerebellum. Time-activity curves were well-fitted by the one-tissue compartment model, with volume of distribution values of 20–40 mL/cm3 for (R)-[11C]NR2B-Me, 8–16 mL/cm3 for (R)-[18F]OF-Me-NB1, and 15–35 mL/cm3 for (S)-[18F]OF-NB1. Estimates of regional non-displaceable binding potential were in the range of 2–3 for (R)-[11C]NR2B-Me and (S)-[18F]-OF-NB1, and 0.5-1 for (R)-[18F]OF-Me-NB1. Altogether, each radiotracer showed an acceptable profile for quantitative imaging of GluN2B. (S)-[18F]OF-NB1 has particularly promising imaging characteristics for potential translation into humans. However, the source of unexpected displaceable binding in the cerebellum for each of these compounds requires further investigation.

Introduction We recently reported 11C-NR2B-SMe ([S-methyl-11C](R,S)-7-thiomethoxy-3-(4-(4-methyl-phenyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepin-1-ol) and its enantiomers as candidate radioligands for imaging the GluN2B subunit within rat N-methyl-D-aspartate receptors. However, these radioligands gave unexpectedly high and displaceable binding in rat cerebellum, possibly due to cross-reactivity with sigma-1 (σ1) receptors. This study investigated 11C-labeled enantiomers of a close analogue (7-methoxy-3-(4-(p-tolyl)butyl)-2,3,4,5-tetrahydro-1H-benzo[d]azepin-1-ol; NR2B-Me) of 11C-NR2B-SMe as new candidate GluN2B radioligands. PET was used to evaluate these radioligands in rats and to assess potential cross-reactivity to σ1 receptors. Methods NR2B-Me was assayed for binding affinity and selectivity to GluN2B in vitro. 11C-NR2B-Me and its enantiomers were prepared by Pd-mediated treatment of boronic ester precursors with 11C-iodomethane. Brain PET scans were conducted after radioligand intravenous injection into rats. Various ligands for GluN2B receptors or σ1 receptors were administered at set doses in pre-blocking or displacement experiments to assess their impact on imaging data. 18F-FTC146 and enantiomers of 11C-NR2B-SMe were used for comparison. Radiometabolites from brain and plasma were measured ex vivo and in vitro. Results NR2B-Me enantiomers showed high GluN2B affinity and selectivity in vitro. 11C-NR2B-Me enantiomers gave high early whole rat brain uptake of radioactivity, including high uptake in cerebellum, followed by slower decline. Radioactivity in brain at 30 min ex vivo was virtually all unchanged radioligand. Only less lipophilic radiometabolites appeared in plasma. When 11C-(R)-NR2B-Me was used, three high-affinity GluN2B ligands—NR2B-SMe, Ro25-6981, and CO101,244—showed increasing pre-block of whole brain radioactivity retention with increasing dose. Two σ1 receptor antagonists, FTC146 and BD1407, were ineffective pre-blocking agents. Together, these results strongly resemble those obtained with 11C-NR2B-SMe enantiomers, except that 11C-NR2B-Me enantiomers showed faster reversibility of binding. When 18F-FTC146 was used as a radioligand, FTC146 and BD1407 showed strong pre-blocking effects whereas GluN2B ligands showed only weak blocking effects. Conclusion 11C-NR2B-Me enantiomers showed specific binding to GluN2B receptors in rat brain in vivo. High unexpected specific binding in cerebellum was not due to σ1 receptors. Additional investigation is needed to identify the source of the high specific binding. Graphical Abstract

Glucosamine hydrochloride (GAH), one of the most basic and important derivatives of chitin, is obtained by hydrolysis of chitin in concentrated hydrochloric acid. At present, little is known about how GAH functions in skeletal development. In this report, we demonstrate that GAH, extracted from the cell wall of Agaricus bisporus, acts in a dose-dependent manner to promote not only cartilage and bone development in larvae but also caudal fin regeneration in adult fish. Furthermore, GAH treatment causes a significant increase in expression of bone-related marker genes, indicating its important role in promoting skeletal development. We show that in both larval and adult osteoporosis models induced by high iron osteogenic defects are significantly ameliorated after treatment with GAH, which regulates expression of a series of bone-related genes. Finally, we demonstrate that GAH promotes skeletal development and injury repair through bone morphogenetic protein (Bmp) signaling, and it works at the downstream of the receptor level. Taken together, our findings not only provide a strong research foundation and strategy for the screening of natural osteoporosis drugs and product development using a zebrafish model but also establish the potential for the development of Agaricus bisporus-derived GAH as a new drug for osteoporosis treatment.

Rapid progress has been made to identify and study the causative agent leading to coronavirus disease 2019 (COVID‐19) but many questions including who is most susceptible and what determines severity remain unanswered. Angiotensin‐converting enzyme 2 (ACE2) is a key factor in the infection process of severe acute respiratory syndrome coronavirus‐2 (SARS‐CoV‐2). In this study, molecularly specific positron emission tomography imaging agents for targeting ACE2 are first developed, and these novel agents are evaluated in vitro, in preclinical model systems, and in a first‐in‐human translational ACE2 imaging of healthy volunteers and a SARS‐CoV‐2 recovered patient (NCT04422457). ACE2 expression levels in different organs in live subjects are quantitatively delineated and observable differences are measured in the patient recovered from COVID‐19. Surprising sites of uptake in the breast, reproductive system and very low uptake in pulmonary tissues are reported. This novel method can add a unique tool to facilitate SARS‐CoV‐2 related research and improve understanding of this enigmatic disease. Molecular imaging provides quantitative annotation of ACE2, the SARS‐CoV‐2 entry receptor, to noninvasively monitor organs impacted by the COVID‐19., Severe acute respiratory syndrome coronavirus‐2 gains infect cells through binding to the angiotensin‐converting enzyme 2 (ACE2) receptor. Using a high affinity radiolabeled peptide to the receptor, the whole body and quantitative determination of ACE2 expression can be imaged. This molecular imaging approach enables animal model and clinical evaluation of this critical receptor, noninvasively.

Purpose: To evaluate whether the European Neuroendocrine Tumor Society (ENETS) system or the 8th American Joint Committee on Cancer (AJCC) staging manual are suitable for gastric neuroendocrine carcinomas and/or mixed adenoneuroendocrine carcinomas (G-NECs/MANECs). Methods: Patients in a multicentric series with G-NEC/MANEC who underwent curative-intent surgical resection for a primary tumor were included. An optimal staging system was proposed base on analysis of the T and N status and validated by the SEER database. Results: Compared with the ENETS system, the survival curves of the T category and N category in the 8th AJCC system were better separated and distributed in a more balanced way, but the survival curves of T2 vs. T3, N0 vs. N1, and N3a vs. N3b overlapped. For the T category, the 8th AJCC T category was modified by combining T2 and T3, which was consistent with the T category in the 6th AJCC manual for GC. For the N category, the optimal cut-off values of metastatic lymph nodes using X-tile were also similar to those of the N category in the 6th AJCC system. The Kaplan-Meier plots of the 6th AJCC system showed statistically significant differences between individual substages. Compared with the other 2 classifications, the 6th AJCC system also showed superior prognostic stratification. Similar results were obtained in both multicentric and SEER validation sets. Conclusions: Compared to the 8th AJCC and ENETS systems, the 6th AJCC staging system for GC is more suitable for G-NEC/MANEC and can be adopted in clinical practice.

1212 Objectives: The pretargeting strategy, which has been proposed as an alternative to radioimmunotherapy, increases the absorbed dose to the tumor while reducing the side effects of normal tissues, resulting in a high therapeutic effect. From the early development stage, the combination of streptavidin and biotin for in vivo binding, which controls the pharmacokinetics and therapeutic effects, has been expected to have clinical application owing to its high affinity for the recognition pair. However, due to the strong immunogenicity of streptavidin in vivo, the streptavidin/biotin pair has not been studied extensively. Hence, we designed Cupid, which is a mutated streptavidin with low immunogenicity and can fuse to four single-chain Fv fragments (scFv), and synthesized Psyche, which is a corresponding biotin variant with a specific affinity to Cupid (Sugiyama et al., Prc. Jpn. Acad. Ser. B 95:602, 2019). In this study, in addition to using these combinations, we labeled Psyche with an alpha-emitting radionuclide 211At, which is expected to have high therapeutic effects in the tumor and fewer side effects on the surrounding tissue in vivo. The aim of this study was to evaluate the labeling, stability, and pharmacokinetics of 211At labeled Psyche and scFV-Cupid in mice. Methods: 211At was produced using 209Bi(α, 2n)211At reaction and isolated through dry distillation. 80 MBq of 211At was labeled to Psyche derivatives (Psyche-B) and purified as a no-carrier-added product using Reversed-Phase HPLC. For the stability evaluation, 211At-Psyche-B was incubated with PBS and serum for 24 h. In total, 1×107 human gastric cancer cells (MKN-45) with a high expression of CEA were xenografted subcutaneously in male, 9-week-old BALB/c nu/nu mice. Thirteen days after the transplantation, 100 pmol of anti-CEACAM5 scFv-Cupid was intravenously administered to mice. After an interval of 24 h, 250 kBq of 211At labeled Psyche-B was intravenously administered to mice. The mice were sacrificed 1 min, 1 h, 6 h, and 24 h after the 211At-Psyche-B injection (n = 3 in each group). Samples were collected from the blood, brain, thyroid, heart, lung, liver, spleen, stomach, small intestine, pancreas, kidney, adrenal gland, muscle, bone, urine, and feces. Subsequently, they were weighed and measured for radioactivity using a gamma counter. Results: The radiochemical yield of 211At-Psyche-B was 96%, as determined by a radio-HPLC analysis of the crude product. 211At-Psyche-B showed high stability in PBS after 24 h but dissociated in serum within 1 h. In the biodistribution study, the clearance of 211At-Psyche-B from blood was 46.4 ± 1.4%ID/g after 1 min, 40.6 ± 3.2 %ID/g after 1 h, 29.4 ± 0.9 %ID/g after 6 h, and 6.2 ± 1.3 %ID/g after 24 h. The accumulation of 211At-Psyche-B in blood decreased with time, and approximately 94% of the injected dose was excreted within 24 h. The accumulation of 211At-Psyche-B in the tumor was 0.6 ± 0.1 %ID/g in 1 min, 3.2 ± 0.4 %ID/g in 1 h, 11.8 ± 1.5 %ID/g in 6 h, and 16.3 ± 4.1 %ID/g in 24 h. The tumor-to-blood ratios were 0.01 ± 0.00 after 1 min, 0.08 ± 0.01 after 1 h, 0.40 ± 0.05 after 6 h, and 2.63 ± 0.10 after 24 h. 211At-Psyche-B showed high liver uptakes in the experiment period: 17.4 ± 2.3 %ID/g in 1 min, 13.6 ± 1.4 %ID/g in 1 h, 16.0 ± 1.4 %ID/g in 6 h, and 15.5 ± 0.1 %ID/g in 24 h. 211At-Psyche-B uptakes in the spleen were 4.9 ± 1.7 %ID/g in 1 min, 7.9 ± 1.1 %ID/g in 1 h, 10.1 ± 0.3 %ID/g in 6 h, and 9.6 ± 2.4 %ID/g in 24 h. 211At-Psyche-B uptakes in the kidney were 29.3 ± 1.5 %ID/g in 1 min, 14.2 ± 1.3 %ID/g in 1 h, 9.8 ± 0.7 %ID/g in 6 h, and 4.7 ± 0.8 %ID/g in 24 hours. Conclusion: Although 211At-Psyche-B showed low serum stability in vitro, tumor uptake was confirmed and accumulation increased over time in vivo. Thus, this study suggested that our pre-targeting strategy of low-immunogenic CEA scFv-Cupid and 211At labeled Psyche might work for advanced cancer treatment. Acknowledgments: This work was financially supported by AMED under Grant Number JP19ck0106414.

The present study was designed to evaluate the dynamic survival and recurrence of remnant gastric cancer (RGC) after radical resection and to provide a reference for the development of personalized follow‐up strategies. A total of 298 patients were analyzed for their 3‐year conditional overall survival (COS3), 3‐year conditional disease‐specific survival (CDSS3), corresponding recurrence and pattern changes, and associated risk factors. The 5‐year overall survival (OS) and the 5‐year disease‐specific survival (DSS) of the entire cohort were 41.2% and 45.8%, respectively. The COS3 and CDDS3 of RGC patients who survived for 5 years were 84.0% and 89.8%, respectively. The conditional survival in patients with unfavorable prognostic characteristics showed greater growth over time than in those with favorable prognostic characteristics (eg, COS3, ≥T3: 46.4%‐83.0%, Δ36.6% vs ≤T2: 82.4%‐85.7%, Δ3.3%; P 0.05). Time‐dependent logistic regression analysis showed that the AJCC stage independently affected recurrence within 2 years after surgery (P, Patients with RGC usually have a high likelihood of death or recurrence within 3 years after radical surgery. We developed a postoperative follow‐up model for RGC patients of different stages.

Key Points Question Are there any differences in prognoses or recurrence patterns associated with gastric neuroendocrine carcinoma, mixed adenoneuroendocrine carcinoma, or adenocarcinoma? Findings This cohort study included 3689 patients with resectable gastric adenocarcinoma, gastric neuroendocrine carcinoma, or gastric mixed adenoneuroendocrine carcinoma. Propensity score matching analysis found that, compared with gastric adenocarcinoma, gastric neuroendocrine carcinoma and gastric mixed adenoneuroendocrine carcinoma were independent risk factors associated with worse disease-free survival, postrecurrence survival, and distant recurrence outcomes. Meaning These findings suggest that different follow-up and treatment strategies should be developed to improve the long-term survival of patients with gastric neuroendocrine carcinoma or gastric mixed adenoneuroendocrine carcinoma, especially for patients with tumors penetrating into the subserosa or deeper layers and with lymph node metastasis., This cohort study examines differences in long-term survival and patterns of recurrence among patients with gastric neuroendocrine carcinoma, gastric mixed adenoneuroendocrine carcinoma, and gastric adenocarcinoma., Importance Gastric neuroendocrine carcinoma and mixed adenoneuroendocrine carcinoma are rare pathological types of gastric cancer, and there is a lack of multicenter studies comparing the prognosis and recurrence patterns of gastric neuroendocrine carcinoma, gastric mixed adenoneuroendocrine carcinoma, and gastric adenocarcinoma. Objective To compare the differences in long-term survival and patterns of recurrence among gastric neuroendocrine carcinoma, gastric mixed adenoneuroendocrine carcinoma, and gastric adenocarcinoma. Design, Setting, and Participants This cohort study included patients with resectable gastric neuroendocrine carcinoma and gastric mixed adenoneuroendocrine carcinoma at 23 hospitals in China from January 2006 to December 2016. In addition, patients with gastric adenocarcinoma were selected as controls. Propensity score–matched analysis was used to match pathological stage among the different pathological types, and disease-free survival (DFS), postrecurrence survival (PRS), and patterns of recurrence were examined. Data analysis was conducted from July 15, 2020, to October 21, 2020. Exposures Curative resection for gastric neuroendocrine carcinoma, gastric mixed adenoneuroendocrine carcinoma, and gastric adenocarcinoma. Main Outcomes and Measures The main outcomes were DFS and patterns of recurrence. Results A total of 3689 patients were analyzed (median [interquartile range] age, 62 [55-69] years; 2748 [74.5%] men), including 503 patients (13.6%) with gastric neuroendocrine carcinoma, 401 patients (10.9%) with gastric mixed adenoneuroendocrine carcinoma, and 2785 patients (75.5%) with gastric adenocarcinoma. After propensity score matching, 5-year DFS was 47.6% (95% CI, 42.7%-52.5%) for patients with gastric neuroendocrine carcinoma, compared with 57.6% (95% CI, 55.1%-60.1%) with gastric adenocarcinoma (P

In this study, three pairs of optically pure 18F-labeled 2-phenylquinoxaline derivatives were evaluated as Tau imaging agents for the diagnosis of Alzheimer's disease (AD). The chiral 2-fluoromethyl-1,2-ethylenediol side chain was attached to the 2-phenylquinoxaline backbone to increase hydrophilicity, thereby improving the binding affinity of the probe to tangles and their selectivity toward Tau tangles over β-amyloid plaques (Aβ). These probes displayed excellent fluorescent properties and high selectivity for tangles on brain sections from transgenic mice (rTg4510) and AD patients. Quantitative binding assays with AD homogenates showed that the probes (R)-5 and (S)-16 have a high affinity (Ki = 4.1 and 10.3 nM, respectively) and high selectivity (30.5-fold and 34.6-fold, respectively) for tangles over Aβ. The high affinity and selectivity of (R)-[18F]5 and (S)-[18F]16 for tangles were further confirmed with autoradiography on AD brain tissue in vitro. In addition, they displayed sufficient blood-brain barrier penetration (7.06% and 10.95% ID/g, respectively) and suitable brain kinetics (brain2 min/brain60 min = 10.1, 6.5 respectively) in normal mice. Ex vivo metabolism studies and micro-positron emission computed tomography (PET) revealed high brain biostability, good brain kinetic properties, and low nonspecific binding for (S)-[18F]16. Together, these results demonstrate that (R)-[18F]5 and (S)-[18F]16 are promising PET probes for Tau tangles imaging.

To establish a novel nomogram to predict individual 1, 3, and 5 years disease-free survival (DFS) of patients with gastric neuroendocrine carcinoma/mixed adenoneuroendocrine carcinoma [(MA)NEC]. Among patients undergoing radical resection of gastric (MA)NEC, there is still a high tendency for relapse. A retrospective analysis of 777 patients with gastric (MA)NEC at 23 centers in China from 2004 to 2015 was performed. Based on the established nomogram, which included age, ASA, pT, pN and Ki67, the overall patients were divided into low-risk group (LRG) and high-risk group (HRG). The median follow-up time was 40 months (1–169 months). The C-index, AUC and time-ROC of the nomogram were significantly higher than that of the 8th edition AJCC and ENETS TNM staging systems. The 3-year DFS of patients in HRG generated by the nomogram was significantly lower than that in LRG (all patients: 35% vs 66.9%, p

For patients with locally advanced proximal gastric cancer (LAPGC), the individualized selection of patients with highly suspected splenic hilar (No. 10) lymph node (LN) metastasis to undergo splenic hilar lymphadenectomy, is a clinical dilemma. This study aimed to re-evaluate the feasibility and safety of laparoscopic spleen-preserving splenic hilar lymphadenectomy (LSPSHL) and to identify the population who would benefit from it. A total of 1068 patients (D2 group = 409; D2 + No. 10 group = 659) who underwent laparoscopic total gastrectomy from four prospective trials between January 2015 and July 2019 were analyzed. No significant difference in the incidence (16.9% vs. 16.4%; P = 0.837) of postoperative complications were found between the two groups. The metastasis rate of No. 10 LN among patients in the D2 + No. 10 group was 10.3% (68/659). Based on the decision tree, patients with LAPGC with tumor invading the greater curvature (Gre), patients with non-Gre-invading LAPGC with a tumor size > 5 cm and clinical positive locoregional LNs were defined as the high-priority No. 10 dissection group. The metastasis rate of No. 10 LNs in the high-priority group was 19.4% (41/211). In high-priority group, the 3-year overall survival of the D2 + No. 10 group was better than that of the D2 group (74.4% vs. 42.1%; P = 0.005), and the therapeutic index of No. 10 was higher than the indices of most suprapancreatic stations. LSPSHL for LAPGC is safe and feasible when performed by experienced surgeons. LSPSHL could be recommended for the high-priority group patients even without invasion of the Gre.

Emerging evidence suggests that microRNAs (miRNAs) serve an important role in tumorigenesis and development. Although the low expression of miR‐125a‐5p in gastric cancer has been reported, the underlying mechanism remains unknown. In the current study, the low expression of miR‐125a‐5p in gastric cancer was verified in paired cancer tissues and adjacent non‐tumour tissues. Furthermore, the GC islands in the miR‐125a‐5p region were hypermethylated in the tumour tissues. And the hypermethylation was negatively correlated with the miR‐125a‐5p expression. Target gene screening showed that the histone methyltransferase Suv39H1 was one of the potential target genes. In vitro studies showed that miR‐125a‐5p could directly suppress the Suv39H1 expression and decrease the H3K9me3 levels. On the other hand, the Suv39H1 could induce demethylation of miR‐125a‐5p, resulting in re‐activation of miR‐125a‐5p. What is more, overexpessing miR‐125a‐5p could also self‐activate the silenced miR‐125a‐5p in gastric cancer cells, which suppressed cell migration, invasion and proliferation in vitro and inhibited cancer progression in vivo. Thus, we uncovered here that the epigenetic silenced miR‐125a‐5p could be self‐activated through targeting Suv39H1 in gastric cancer, suggesting that miR‐125a‐5p might be not only the potential prognostic value as a tumour biomarker but also potential therapeutic targets in gastric cancer.

Altered expression of microRNA (miRNA) is strongly implicated in gastric cancer (GC). Here, we demonstrated a decreased expression of miRNA-329 in GC. Then we explored the regulatory mechanisms responsible for its effect on GC cells. GC tissues and their adjacent non-tumor tissues were collected. Complete follow-up was updated. A series of inhibitors, mimics, and siRNA against KDM1A were introduced to validate regulatory mechanisms for miR-497 and KDM1A in BGC-823 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot assay were employed for evaluating the expressions of miRNA-329, KDM1A, H3K4me1, and H3K4me2. Cell proliferation, cycle progression, and apoptosis were assessed by means of an MTT assay and flow cytometry. Cell colony formation was assessed. uman gastric cancer xenotransplanted into nude mice was studied. As opposed to adjacent tissues and gastritis tissues, miRNA-329 was highly expressed and KDM1A was low expressed in GC tissues. The patients with high miRNA-329 expression or low KDM1A expression had longer survival periods. The miRNA-329 mimics and siRNA against KDM1A decreased KDM1A expression and increased H3K4me1 and H3K4me2 expressions. Forced expression of miRNA-329 in gastric cancer cells significantly promotes their capacity of apoptosis but reduces proliferation, migration, and invasion. KDM1A is a direct downstream target for miRNA-329. In a nude mouse subcutaneous tumor system, in vivo tumor growth of BGC-823 was significantly inhibited after treatment of miRNA-329 mimics or siRNA against KDM1A. We conclude that miRNA-329 functions as a tumor suppressor in GC, which could be achieved via transcriptional suppression of KDM1A.

Positron emission tomography (PET) is an important molecular imaging technique for medical diagnosis, biomedical research and drug development. PET tracers for molecular imaging contain β+-emitting radionuclides, such as carbon-11 (t1/2 = 20.4 min) or fluorine-18 (t1/2 = 109.8 min). The [18F]2-fluoro-pyridyl moiety features in a few prominent PET radiotracers, not least because this moiety is usually resistant to unwanted radiodefluorination in vivo. Various methods have been developed for labeling these radiotracers from cyclotron-produced no-carrier-added [18F]fluoride ion, mainly based on substitution of a leaving group, such as halide (Cl or Br), or preferably a better leaving group, such as nitro or trimethylammonium. However, precursors with a good leaving group are sometimes more challenging or lengthy to prepare. Methods for enhancing the reactivity of more readily accessible 2-halopyridyl precursors are therefore desirable, especially for early radiotracer screening programs that may require the quick labeling of several homologous radiotracer candidates. In this work, we explored a wide range of additives for beneficial effect on nucleophilic substitution by [18F]fluoride ion in 5-subsituted 2-halopyridines (halo = Cl or Br). The nucleophilic cyclic tertiary amines, quinuclidine and DABCO, proved effective for increasing yields to practically useful levels (> 15%). Quinuclidine and DABCO likely promote radiofluorination through reversible formation of quaternary ammonium intermediates.

Background and Objective: Few reports address the impact of surgery on the prognosis of rare and heterogeneous gastric neuroendocrine neoplasms (G-NENs). This study analyzed the influence of surgical treatments on prognosis to provide a personalized surgical treatment strategy for G-NEN patients. Methods: The clinicopathological data of 1126 G-NEN patients from 28 Chinese hospitals were analyzed. Cox regression analyses were used to analyze the prognostic factors affecting survival and recurrence, respectively. Results: Cox analysis revealed that in stage I-II but not stage III gastric neuroendocrine carcinoma/mixed adenoneuroendocrine carcinoma (NEC/MANEC) patients, Extended lymph node dissection (ELND) was an independent protective factor for OS and DFS (p 0.05). Furthermore, among patients with stage III disease, the incidence of complications after ELND was significantly greater than that after LLND (28.4% vs. 12.1%, p < 0.001), especially severe complications (Clavien-Dindo grade III-V). Conclusion: ELND may lead to enhanced long-term survival for stage I and II but not stage III NEC/MANEC patients. Our results in multicenter patients do not support the routine use of ELND in stage III NEC/MANEC patients. Funding Statement: This work was supported by National natural science foundation of China (No.81871899); Scientific and technological innovation joint capital projects of Fujian Province (2016Y9031, 2017Y9011); Construction Project of Fujian Province Minimally Invasive Medical Center (No. [2017]171); The second batch of special support funds for Fujian Province innovation and entrepreneurship talents (2016B013). China scholarship council (201908350095). National natural science foundation of China (No.81802312). Declaration of Interests: None of the authors have any competing interests in the manuscript. Ethics Approval Statement: The research proposal was reviewed by the Research Ethics Committee at the university, and all procedures were performed after obtaining written informed consent from the patients following an explanation of the surgical and oncological risks.

Background: Apatinib, a tyrosine kinase inhibitor targeting vascular endothelial growth factor receptor 2 (VEGFR-2), is a novel treatment option for advanced gastric cancer (AGC) refractory to two or more lines of prior chemotherapy but has not yet been evaluated in patients with locally AGC. This trial investigated the efficacy and safety of apatinib combined with S-1 plus oxaliplatin (SOX) as a neoadjuvant treatment for locally AGC. Methods: Patients with M0 and either T2-T4 or N+ disease received apatinib (500 mg orally once daily on days 1-21 and discontinued in the last cycle) plus SOX (S-1, 40-60 mg orally twice daily on days 1-14; oxaliplatin, 130 mg/m2 intravenously on day 1) given every 3 weeks for 2-5 cycles. D2 gastrectomy was performed 2-4 weeks after the last cycle. To further compare the efficacy and safety between apatinib plus SOX (ASOX group) and SOX alone (SOX group), we reviewed historical control patients receiving SOX as neoadjuvant chemotherapy at the central center. The primary end point was the R0 resection rate. Findings: Between July 2017 and June 2019, 48 and 58 patients were enrolled in the ASOX and SOX groups, respectively. Forty patients in the ASOX group (83.3%) and 47 patients in the SOX group (81.0%) underwent surgery, with R0 resection rates of 75.0% and 67.2%, respectively (P=0.382). For patients proceeding surgery, the R0 resection rates were 90.0% (36/40) and 82.3% (39/47), respectively (P = 0.534). The proportion of patients with T downstaging in the ASOX group was significantly higher than that in the SOX group (36.4% vs 18.5%, P=0.036). For patients with target lesions, the radiological response rate was significantly higher in the ASOX group (75.0% vs 38.5%, P=0.015). Moreover, the ASOX group was associated with significantly higher proportions of patients achieving major pathological response (25.0% vs 10.3%, P=0.046). Grade 3 toxicities occurred in 33.3% of the ASOX patients, and no grade 4 toxicities or drug-related deaths were observed. Interpretation: Apatinib combined with SOX showed promising efficacy with an acceptable safety profile as the first-line neoadjuvant treatment for locally AGC. Trial Registration: The trial is registered with ClinicalTrials.gov, number NCT03192735. Funding Statement: This study was supported by Scientific and technological innovation joint capital projects of Fujian Province, China (No.2017Y9011, No.2017Y9004). Minimally invasive medical center of Fujian Province (No. [2017]171). National natural science foundation of China (No.81871899). The second batch of special support funds for Fujian Province innovation and entrepreneurship talents (No.2016B013). Declaration of Interests: There are no conflicts of interest or financial ties to disclose from any authors. Ethics Approval Statement: The informed consent form and study protocol were approved by the Institutional Review Boards of each participating institution. The study was conducted in accordance with the International Conference on Harmonization Good Clinical Practice guidelines, the Declaration of Helsinki, and Chinese law. All patients provided written informed consent before enrollment.

Over the last half-century, the molecular imaging technique of positron emission tomography (PET) has emerged as an important tool for biomedical research, drug development and medical diagnosis. The power of PET derives from its utilization of radiotracers that can report specific information on pharmacology, biochemistry, and physiology. Many of these radiotracers are heterocycles that have been labeled with a short-lived cyclotron-produced radioisotope, either carbon-11 (t1/2 = 20.4 min) or fluorine-18 (t1/2 = 109.8 min). This review addresses the chemical challenges to be met in producing PET radiotracers with these radioisotope labels at heterocyclic moieties and the methods now available for doing so.

The aim of this study was to evaluate whether adjuvant chemotherapy is associated with improved survival in patients with resectable gastric neuroendocrine carcinomas (G-NECs) or mixed adenoneuroendocrine carcinomas (G-MANECs).The study included patients with G-NECs or G-MANECs who underwent surgery in one of 21 centres in China between 2004 and 2016. Propensity score matching analysis was used to reduce selection bias, and overall survival (OS) in different treatment groups was estimated by the Kaplan-Meier method.In total, 804 patients with resectable G-NECs or G-MANECs were included, of whom 490 (60·9 per cent) received adjuvant chemotherapy. After propensity score matching, OS in the chemotherapy group was similar to that in the no-chemotherapy group. Among patients with G-NECs, survival in the fluorouracil (5-FU)-based chemotherapy group and the non-5-FU-based chemotherapy group was similar to that in the no-chemotherapy group. Similarly, etoposide plus cisplatin or irinotecan plus cisplatin was not associated with better OS in patients with G-NECs. Among patients with G-MANECs, OS in the non-5-FU-based chemotherapy group was worse than that in the no-chemotherapy group. Patients with G-MANECs did not have better OS when platinum-based chemotherapy was used.There was no survival benefit in patients who received adjuvant chemotherapy for G-NECs or G-MANECs.El objetivo de este estudio fue evaluar si la quimioterapia adyuvante mejoraba la supervivencia en pacientes con carcinomas gástricos resecables neuroendocrinos (gastric neuroendocrine carcinomas, G-NECs) y carcinomas adenoneuroendocrinos mixtos (mixed adenoneuroendocrine carcinomas, G-MANECs). MÉTODOS: Se incluyeron pacientes con G-NECs y G-MANECs tratados quirúrgicamente en 21 centros en China entre 2004 y 2016. Se utilizó un análisis de emparejamiento por puntaje de propensión para reducir el sesgo de selección y el método de Kaplan-Meier para estimar la supervivencia global (overall survival, OS) de los pacientes en los diferentes grupos de tratamiento.En total, se incluyeron en el estudio 804 pacientes con G-NECs y G-MANECs resecables y 490 pacientes (60,9%) recibieron quimioterapia adyuvante. Después del emparejamiento por puntaje de propensión, la OS del grupo con quimioterapia fue similar a la del grupo sin quimioterapia. En los pacientes con G-NECs, la supervivencia en los grupos con quimioterapia basada en 5-FU (fluorouracilo) y de quimioterapia sin 5-FU fue similar a la del grupo sin quimioterapia. Asimismo, la combinación de etopósido y cisplatino o de irinotecán y cisplatino no se asoció con una mejor OS en pacientes con G-NECs. En pacientes con G-MANECs, la OS del grupo con quimioterapia sin 5-FU fue peor que la del grupo sin quimioterapia. Los pacientes con G-MANECs no presentaron una mejor OS cuando se administró quimioterapia basada en platinos. CONCLUSIÓN: La administración de quimioterapia adyuvante en pacientes con G-NECs y G-MANECs no mejoró la supervivencia.

Previous retrospective studies have shown that laparoscopic spleen-preserving D2 total gastrectomy (LSTG) for advanced upper third gastric cancer (AUTGC) is safe. However, all previous studies were underpowered. We therefore conducted a prospective, multicenter study to evaluate the technical safety and feasibility of LSTG for patients with AUTGC. Patients diagnosed with AUTGC (cT2-4a, N−/+, M0) underwent LSTG at 19 institutions between September 2016 and October 2017 were included. The number of No. 10 lymph node (LN) dissections, metastasis rates, intraoperative and postoperative complications were investigated. A total of 251 patients were enrolled in the study, and 242 patients were eligible for the per protocol analysis. The average numbers of No. 10 LN dissections and metastases were 2.4 and 0.1, respectively. Eighteen patients (7.4%) had No. 10 LN metastases, and among patients with advanced gastric cancer, the rate of No. 10 LN metastasis was 8.1% (18/223). pN3 status was an independent risk factor for No. 10 LN metastasis. Intraoperative complications occurred in 7 patients, but no patients required conversion to open surgery or splenectomy. The overall postoperative complication rate was 13.6% (33/242). The major complication and mortality rates were 3.3% (8/242) and 0.4% (1/242), respectively. The number of retrieved No. 10 LNs, No. 10 LN metastasis and TNM stage had no significant influence on postoperative complication rates. LSTG for AUTGC was safe and effective when performed by very experienced surgeons, this technique could be used in patients who needed splenic hilar lymph node dissection.

Importance Apatinib is a novel treatment option for chemotherapy-refractory advanced gastric cancer (GC), but it has not been evaluated in patients with locally advanced GC. Objective To investigate the effectiveness and safety of apatinib combined with S-1 plus oxaliplatin (SOX) as a neoadjuvant treatment for locally advanced GC. Design, setting, and participants This multicenter, prospective, single-group, open-label, phase 2 nonrandomized controlled trial was conducted in 10 centers in southern China. Patients with M0 and either clinical T2 to T4 or N+ disease were enrolled between July 1, 2017, and June 30, 2019. Statistical analysis was performed from December 1, 2019, to January 31, 2020. Interventions Eligible patients received apatinib (500 mg orally once daily on days 1 to 21 and discontinued in the last cycle) plus SOX (S-1: 40-60 mg orally twice daily on days 1 to 14; oxaliplatin: 130 mg/m2 intravenously on day 1) every 3 weeks for 2 to 5 cycles. A D2 gastrectomy was performed 2 to 4 weeks after the last cycle. Main outcomes and measures The primary end point was R0 resection rate. Secondary end points were the response rate, toxic effects, and surgical outcome. Results A total of 48 patients (mean [SD] age, 63.2 [8.2] years; 37 men [77.1%]) were enrolled in this study. Forty patients underwent surgery (38 had gastrectomy, and 2 had exploratory laparotomy), with an R0 resection rate of 75.0% (95% CI, 60.4%-86.4%). The radiologic response rate was 75.0%, and T downstaging was observed in 16 of 44 patients (36.4%). The pathological response rate was 54.2% (95% CI, 39.2%-68.6%); moreover, this rate was significantly higher in patients who achieved a radiologic response compared with those who did not (12 [80.0%] vs 1 [20.0%]; P = .03) and in those who had an Eastern Cooperative Oncology Group Performance Status score of 0 (20 [76.9%] vs 10 [45.5%]; P = .03) or had tumors located in the upper one-third of the stomach (16 [61.5%] vs 7 [31.8%]; P = .04). Patients who achieved a pathological response (vs those who did not) had significantly less blood loss (median [range]: 60 [10-200] mL vs 80 [20-300] mL; P = .04) and significantly more lymph nodes harvested (median [range]: 40 [24-67] vs 32 [19-51]; P = .04) during surgery. Postoperative complications were observed in 7 of 38 patients (18.4%). Grade 3 toxic effects occurred in 16 of 48 patients (33.3%), and no grade 4 toxic effects or preoperative deaths were observed. Conclusions and relevance This nonrandomized controlled trial found that apatinib combined with SOX was effective and had an acceptable safety profile as a neoadjuvant treatment for locally advanced GC. A large-scale randomized clinical trial may be needed to confirm the findings. Trial registration ClinicalTrials.gov Identifier: NCT03192735.

[(18)F]THK-523 and [(18)F]807 are promising radioligands for imaging neurofibrillary tangles (NFTs) with positron emission tomography (PET) in neurodegenerative diseases, such as Alzheimer's disease (AD) and traumatic brain injury. Although [(18)F]THK-523 and [(18)F]T807 are considered high-affinity selective radioligands for NFTs, uncertainty has existed as to whether PET radioligands for imaging NFTs bind to the same molecular site because in vitro assays for ligands binding to NFTs have been lacking. We labeled THK-523 and T807 with tritium to serve as reference radioligands for in vitro binding assays with AD brain homogenates for newly synthesized ligands. With these radioligands, we identified two distinct binding sites for small molecules, one site with high affinity for THK-523 and the other with high affinity for T807. Moreover, binding assays with [(3)H]PIB confirmed that the two newly identified binding sites are also distinct from the thioflavin-T binding site where all current clinically useful PET radioligands for imaging β-amyloid plaque bind with high affinity. The two newly identified binding sites are considered to reside on NFTs rather than on β-amyloid plaques. Furthermore, we applied all three binding assays to a set of newly prepared compounds, based on chain modifications to THK-523. Some compounds with high affinity and selectivity for the THK-523 binding site emerged from this set, including one with amenability to labeling with fluorine-18, namely, ligand 10b.

TPS4647 Background: Postoperative chemotherapy (S-1, CAPOX, or Docetaxel/S-1) is a standard treatment for stage II/III gastric cancer in Asia. With regard to single agent or doublet, the need for improvement has consistently been pointed out because of the relatively poor outcome for patients with stage III gastric cancer. Triplet (FLOT) has shown significant survival benefits in perioperative setting. POF, our regiment similar to FLOT, demonstrated priority to doublet (FOLFOX) in advanced setting (2019 ASCO-GI). We conducted a randomized, multicenter, phase III study to compare triplet to doublet regimens for patients with stage III gastric cancer. Methods: This is currently enrolling patients (n = 544) with pathologic stage III gastric cancer after D2 lymph node dissection. Patients are randomized 1:1 and stratified by tumor stage (IIIA, IIIB, or IIIC, AJCC 8th) into POF or SOX/CAPOX/FOLFOX (chosen by the clinicians). SOX: oxaliplatin 130 mg/m2 on day 1, oral S-1 80mg/m2 divided by two on days 1 to 14 every 21 days for 8 cycles. CAPOX: oxaliplatin 130 mg/m2 on day 1, oral capecitabine 1000 mg/m2 twice daily on days 1 to 14 every 21 days for 8 cycles. FOLFOX: oxaliplatin 85 mg/m2, levo-leucovorin 200 mg/m2, and 5-FU 400 mg/m2 bolus on day 1, then 5-FU 2400 mg/m2 continuous infusion over 46 hours, every 14 days for 12 cycles. Three doublets were chosen by the clinicians. POF: paclitaxel 135 mg/m2, followed by FOLFOX omitted 5-FU bolus, every 14 days for 12 cycles. Eligibility criteria: patients aged 18-70 years, primary histologically proven gastric adenocarcinoma (including adenocarcinoma of the gastroesophageal junction) of stage III with no evidence of metastatic disease, R0 resection with D2 lymph node dissection, good performance status (ECOG PS ≤1). Subjects must be able to take orally, and without other concomitant medical conditions that required treatment, initially treated with curative surgery followed by chemotherapy within 42 days. Life expectancy estimated more than 6 months. Adequate organ function. All patients provided written informed consent prior to treatment. Key exclusion criteria: patients with other primary malignancies, gastrointestinal bleeding. The primary end point is 3-year disease-free survival. Secondary end points are 3-year overall survival, 5-year overall survival, 5-year disease-free survival, and adverse events. Clinical trial information: NCT03788226 .

Background. Remnant gastric cancer (RGC) is a rare malignant tumor with poor prognosis. There is no universally accepted prognostic model for RGC. Methods. We analyzed data for 253 RGC patients who underwent radical gastrectomy from 6 centers. The prognosis prediction performances of the AJCC7th and AJCC8th TNM staging systems and the TRM staging system for RGC patients were evaluated. Web-based prediction models based on independent prognostic factors were developed to predict the survival of the RGC patients. External validation was performed using a cohort of 49 Chinese patients. Results. The predictive abilities of the AJCC8th and TRM staging systems were no better than those of the AJCC7th staging system (c-index: AJCC7th vs. AJCC8th vs. TRM, 0.743 vs. 0.732 vs. 0.744; P>0.05). Within each staging system, the survival of the two adjacent stages was not well discriminated (P>0.05). Multivariate analysis showed that age, tumor size, T stage, and N stage were independent prognostic factors. Based on the above variables, we developed 3 web-based prediction models, which were superior to the AJCC7th staging system in their discriminatory ability (c-index), predictive homogeneity (likelihood ratio chi-square), predictive accuracy (AIC, BIC), and model stability (time-dependent ROC curves). External validation showed predictable accuracies of 0.780, 0.822, and 0.700, respectively, in predicting overall survival, disease-specific survival, and disease-free survival. Conclusions. The AJCC TNM staging system and the TRM staging system did not enable good distinction among the RGC patients. We have developed and validated visual web-based prediction models that are superior to these staging systems.

Positron emission tomography (PET) is an important molecular imaging technique for medical diagnosis, biomedical research and drug development. PET tracers for molecular imaging contain β+-emitting radionuclides, such as carbon-11 (t1/2 = 20.4 min) or fluorine-18 (t1/2 = 109.8 min). The [18F]2-fluoro-pyridyl moiety features in a few prominent PET radiotracers, not least because this moiety is usually resistant to unwanted radiodefluorination in vivo. Various methods have been developed for labeling these radiotracers from cyclotron-produced no-carrier-added [18F]fluoride ion, mainly based on substitution of a leaving group, such as halide (Cl or Br), or preferably a better leaving group, such as nitro or trimethylammonium. However, precursors with a good leaving group are sometimes more challenging or lengthy to prepare. Methods for enhancing the reactivity of more readily accessible 2-halopyridyl precursors are therefore desirable, especially for early radiotracer screening programs that may require the quick labeling of several homologous radiotracer candidates. In this work, we explored a wide range of additives for beneficial effect on nucleophilic substitution by [18F]fluoride ion in 5-subsituted 2-halopyridines (halo = Cl or Br). The nucleophilic cyclic tertiary amines, quinuclidine and DABCO, proved effective for increasing yields to practically useful levels (> 15%). Quinuclidine and DABCO likely promote radiofluorination through reversible formation of quaternary ammonium intermediates.

We aimed to label tubastatin A (1) with carbon-11 (t1/2 = 20.4 min) in the hydroxamic acid site to provide a potential radiotracer for imaging histone deacetylase 6 in vivo with positron emission tomography. Initial attempts at a one-pot Pd-mediated insertion of [(11)C]carbon monoxide between the aryl iodide (2) and hydroxylamine gave low radiochemical yields (

N-Methyl-d-aspartate (NMDA) receptor dysfunction has been linked to several neuropsychiatric disorders, including Alzheimer's disease, epilepsy, drug addiction, and schizophrenia. A radioligand that could be used with PET to image and quantify human brain NMDA receptors in the activated "open channel" state would be useful for research on such disorders and for the development of novel therapies. To date, no radioligands have shown well-validated efficacy for imaging NMDA receptors in human subjects. In order to discover improved radioligands for PET imaging, we explored structure-affinity relationships in N'-3-(trifluoromethyl)phenyl derivatives of N-aryl-N'-methylguanidines, seeking high affinity and moderate lipophilicity, plus necessary amenability for labeling with a positron-emitter, either carbon-11 or fluorine-18. Among a diverse set of 80 prepared N'-3-(trifluoromethyl)phenyl derivatives, four of these compounds (13, 19, 20, and 36) displayed desirable low nanomolar affinity for inhibition of [(3)H](+)-MK801 at the PCP binding site and are of interest for candidate PET radioligand development.

A method was established for the determination of fipronil and its metabolites in eggs and egg products with gas chromatography-negative chemical ionization-mass spectrometry (GC-NCI-MS). The targets were extracted from samples with acetonitrile, and followed by a simple cleanup step known as dispersive solid-phase extraction QuEChERS. The extracts were determined by GC-NCI-MS, and quantified by external standard method with matrix correction standard curves. The recoveries were in the range of 87.0% to 99.3% at four spiked levels (0.1, 2.0, 4.0 and 20.0 μg/kg), and all RSDs were not more than 12.7% for the four analytes. The linearity of the method was good between 0.005 and 0.10 mg/L, and all LOQs were less than 0.10 μg/kg. So this method can be used to determine the residues of fipronil and its metabolites in eggs and egg products.

An expansive set of N -aryl- N ′-(3-(substituted)phenyl)- N ′-methylguanidines was prepared in a search for new leads to prospective PET ligands for imaging of the open channel of the N -methyl- d -aspartate (NMDA) receptor in vivo. The N -aryl rings and their substituents were varied, whereas the N -methyl group was maintained as a site for potential labeling with the positron-emitter, carbon-11 ( t 1/2 = 20.4 min). At micromolar concentration, over half of the prepared compounds strongly inhibited the binding of [ 3 H]TCP to its binding site in the open NMDA receptor in vitro. Four ligands displayed affinities that are similar or superior to those of the promising SPECT radioligand ([ 123 I]CNS1261). The 3′-dimethylamino ( 19 ; K i 36.7 nM), 3′-trifluoromethyl ( 20 ; K i 18.3 nM) and 3′-methylthio ( 2 ; K i 39.8 nM) derivatives of N -1-naphthyl- N ′-(phenyl)- N ′-methylguanidine were identified as especially attractive leads for PET radioligand development.

How to identify whether T1-2 colorectal cancers have lymph nodes metastases pre-op or intra-op is a crucial problem in clinic. The purpose of this study was to evaluate the feasibility of using carbon nanoparticles to track lymph nodes metastases in T1-2 colorectal cancers.A multi-center study was performed between July 2012 and January 2014. Seventy-three patients with T1-2 colorectal cancer identified by pre-op endoscopic ultrasonography (EUS) were recruited. 1 ml carbon nanoparticles suspension was endoscopically injected into the submucosal layer at four points around the site of the primary tumor 1 day before surgery. Laparoscopic radical resection with lymphadenectomy was performed. Sentinel lymph nodes (SLNs) were defined as nodes that were black-dyed by carbon nanoparticles. Pathology confirmed whether lymph nodes have cancer metastases and the SLNs accuracy.SLNs were easily found under laparoscopy. The mean number of SLNs was 3 (range 1-5). All patients had SLNs lying alongside the mesenteric vessel or main arterial vessel. After pathological analysis, 2 patients (9.52%) had lymph node metastasis in 21 patients with EUS T1 cancers, and 10 patients (19.23%) had lymph node metastasis in 52 patients with EUS T2 cancers. In two T1 cases with lymph node metastasis, SLNs were positive with 100% accuracy. In ten T2 cases with lymph node metastasis, SLNs were positive in nine cases. In pathology, carbon nanoparticles were seen in lymphatic vessels, and lymphoid sinus and macrophages in negative SLNs. When SLNs were positive, carbon nanoparticles were seen around cancer cells in lymph nodes. The overall sensitivity, specificity, accuracy of SLNs in T1-2 colorectal cancers were 91.67, 100, 98.63%, respectively.We demonstrated the feasibility of using carbon nanoparticles to track lymph nodes metastases in T1-2 colorectal cancers. Carbon nanoparticles black-dyed lymph nodes play a role as SLNs in T1-2 colorectal cancers.

To clarify the priority of lymph node dissection (LND) in advanced Siewert type II and III AEG, in which the center of the tumor is located below the esophagogastric junction (EGJ). Data in 395 patients with advanced Siewert type II or III AEG was analyzed retrospectively. The index of estimated benefit from LND (IEBLD) was used to evaluate the efficacy of LND for each nodal station. The mean number of dissected LNs did not differ significantly between patients with type II and III AEG, nor did the mean number of retrieved LNs at each station significantly differ between the 2 groups. According to the IEBLD, the dissection of parahiatal LNs (No.19 and 20) and LNs along the distal portion of the stomach (No.5, 6, and 12a) seemed unlikely to be beneficial, whereas the dissection of Nos.1–3, 7, 9 and 11p yielded high therapeutic benefit (IEBLD>3.0) in both groups. The IEBLDs of No.4d, 8a, and 10 were much higher in type III than in type II AEG cases. No.10 LND may improve survival for type III AEG cases (IEBLD = 2.9), especially for subgroups with primary tumors invading the serosa layer, undifferentiated cancers, macroscopic type 3–4 tumors and tumors ≥50 mm in size (all IEBLDs > 4.0). For advanced AEG located below the EGJ, the dissection of paracardial LNs, lesser curvature LNs, and LNs around the celiac axis would promote higher survival benefits regardless of the Siewert subtype. Patients with type III AEG, especially those with serosa-invasive tumors, undifferentiated tumors, macroscopic type 3–4 tumors and tumors ≥50 mm in size may obtain relatively higher survival benefits from No. 10 lymphadenectomy.

e15552 Background: As the fifth most common malignancies and the third leading cause of cancer death in the world, gastric cancer (GC) is often diagnosed in locally advanced or metastatic stage and, therefore, has a poor prognosis. Copy number instability (CNI) score, interpreted as the general measure of genomic instability, was reported as a prognosis predictor of some types of cancer, but its role in prognosis of GC patients remains unknown. The aim of the present study was to investigate its prognostic value in patients with GC after surgical resection and adjuvant chemotherapy. Methods: The present study included 120 patients who had received gastrectomy and adjuvant chemotherapy with stage II-IV GC. Follow-up was available for them. DNA was extracted from primary formalin-fixed paraffin-embedded (FFPE) tumor specimens and matched blood samples. Genomic profiles were analyzed by using a designed panel (1408 genes) based on next generation sequencing (NGS). Results: The most frequently mutated genes were TP53 (49%), PIK3CA (8%), RNF43 (6%) ERBB3 (6%) and APC (6%), and the most frequently amplified genes were TRPS1 (41%), COL1A2 (31%), CSMD3 (29%), ZFHX4 (29%), NAV3 (23%). CNI score was negatively correlated with OS, the CNI-high group had markedly shorter OS than CNI-low group ( p= 0.0093). In addition, there were statistically significant differences in OS between different clinical staging ( p= 0.0468). Moreover, the Cox proportional hazard model showed that CNI score was an independent prognosis factor in GC. Conclusions: The current study indicates that CNI score in primary tumor tissue is an independent predictive prognostic biomarker for GC.

51 Background: Gastric cancer (GC) is a highly heterogeneous disease. Cell-free DNA (cfDNA) has been a research hotspot in molecular tumor profiling. In advanced GC patients, malignant pleural effusion (MPE) and ascites provide a wealth of tumor cells that can be investigated. The aim of this study is to investigate fusion landscape in advanced GC. Methods: A multicenter study in China was initiated from Aug. 2016, and GC patients have been enrolled as of Aug. 2018. To determine the fusion frequency in GC, we analyzed data from 371clinical GC cases, each of which had results from next-generation sequencing (NGS)-based 381 genes panel assay, analogous to the index patient. Results: Of this entire cohort, 61 patients (16.44%) were identified with fusions, including TMEM45B-FGF3 (3), AXIN1-SMPD3 (3), B3GNTL1-ERBB2 (2), ERBB2-LAMA3 (2), ERBB2-ACLY (2), TRIM24-BRAF (2), ARHGEF1-CD79A (2), FGFR4-UIMC1 (2), MSH2-TTC7A (2), SMARCA4-LDLR (2), GON4L-RIT1 (2), AKT1-CPSF2 (2), GATA6-COLEC12 (2), RICTOR-EFNA5 (2), KAT6A-PLAT (2), ROCK1-CCDC178 (2), HBS1L-MYB (2), SLC30A2-ARID1A (2), MSI2-BIRC5 (2), NOTCH3-UCA1 (2), PIK3C2B-KISS1 (2), RICTOR-OSMR (2), FGFR2-MIR5694 (2), FGFR2-FGFR1 (2), MAN2A2-BLM (2), EGFR-MED15 (1), EML4-ALK(1), GOPC-ROS1 (1), FXR2-TP53 (1), NF1-PSMD11 (1), IRS2-PRKCI (1), FGFR2-KIAA1217(1), FGFR2-TACC2 (1), FGFR3-TACC3 (1). ERBB2, BRAF, EGFR, ALK and ROS1 fusionswere seen in 18.03% (11/61) of advanced Chinese gastric cancer fusion landscape patients. Conclusions: Advanced Chinese gastric cancer fusion landscape is rich, ERBB2, BRAF, EGFR, ALK and ROS1 fusions are rare but potentially druggable in TKIs. Detection of ERBB2, BRAF, EGFR, ALK and ROS1 fusions should be part of comprehensive profiling panels to determine TKIs and direct appropriate combination therapeutic strategies.

[11C]Methyl iodide is the most widely used reagent for labeling radiotracers with carbon-11 (t1/2 = 20.4 min) for molecular imaging with positron emission tomography. However, some substrates for labeling, especially primary arylamines and pyrroles, are sluggishly reactive towards [11C]methyl iodide. We found that insoluble inorganic bases, especially Li3N or Li2O, effectively promote rapid reactions (≤ 10 min) of such substrates with no-carrier-added [11C]methyl iodide in N,N-dimethylformamide (DMF) at room temperature to give 11C-methylated products in useful radiochemical yields. In particular, we discovered that some primary arylamines in Li3N/DMF were converted into their corresponding formanilides, and that these were readily N-methylated with [11C]methyl iodide, which preceded easy basic hydrolysis to the desired [11C]N-methyl secondary arylamines. The use of a solid base permitted selective reaction at an arylamino group and, in some cases, avoided undesirable side reactions, such as ester group hydrolysis. An ultrasound device proved useful to provide remote and constant agitation of the radioactive heterogeneous reaction mixtures but imparted no ultrasound-specific chemical effect.

Palladium-catalyzed coupling between aryl halides, especially less reactive ones or N-heteroaryls, and trimethylsilylacetylene in the presence of dimethylaminotrimethyltin generated the coupled products in high yields. The reaction does not need CuI and base as auxiliary agents.

The scope of protection for gene technology patents in China is still narrow compared with that of Europe and the United States.

A highly efficient method for specific synthesis of N-monomethylarylamines is presented. Anilines were treated with acetic anhydride and triethylamine in dry CH2Cl2 to give the corresponding acetamides. The subsequent N-monomethylation of acetyl aryl amines with methyl iodide and NaH in THF introduced methyl group. Acid hydrolysis of the N-methyl acetanilides in ethylene glycol generated the corresponding N-methyl-N-aryl amines in high yields. This method was also used to synthesize (E)-2-bromo-5-(4-methylaminostyryl)pyridine that may be useful as an amyloid imaging agent for Alzheimer’s disease.

Alzheimers disease (AD) is characterized pathologically by the accumulation of β-amyloid plaques in brain. We developed a novel positron emission tomographic (PET) radioligand, [11C]MeS-IMPY ([S-methyl-11C]N,N-dimethyl- 4-(6-(methylthio)imidazo[1,2-a]pyridine-2-yl)aniline). The objective of this study was to determine if [11C]MeS-IMPY can detect β-amyloid plaques in patients with AD. Ten subjects (4 patients with AD and 6 healthy controls) had PET scans of 90 min as well as serial sampling of arterial plasma. Total distribution volume was calculated from radioactivity in brain and concentrations of radioligand in arterial plasma. After injection of [11C]MeS-IMPY in both groups, peak brain uptake was high (∼ 450% SUV), peaked early at ∼ 2 min and washed out quickly. The time-course of brain radioactivity in all regions was virtually identical in AD patients and healthy controls. Although distribution volume of neocortical regions was ∼ 26% higher in AD patients than in controls, the differences were statistically insignificant (P = 0.143). In addition, distribution volume in all regions and in both groups increased during the entire scan, which is consistent with the accumulation of radiometabolite(s) in brain. The rapid washout of [11C]MeS-IMPY from brain may have been caused by inadequate binding affinity, and the small differences between patients and healthy subjects were likely caused, in part, by the accumulation of radiometabolite(s) in brain. We conclude that [11C]MeS-IMPY is able to image β-amyloid in brains of patients with AD, but that chemical analogs with higher affinity and non-problematic radiometabolites will be more useful imaging agents.

Various aryl triflates, bearing ketone or aldehyde groups, were evaluated for palladium-mediated introduction of an amino group at the triflate position in the presence of various phosphine ligands. BINAP was best for secondary amines, MOP-type ligand for primary or small secondary amines and Xantphos for primary or cyclic secondary amides. No ligand was found effective for acyclic secondary amides.