Trigonometric-spline dwell time scheduling and real-time interpolator under dynamic constraints for deterministic polishing.

Dwell time scheduling is a critical stage of deterministic polishing for ultra-precision fabrication of optics. Recently the dwell time algorithms for deterministic polishing have been widely studied. Nevertheless, there exist some shortcomings when those methods were applied in the industry, including low computational efficiency, large memory consumption, insufficiently-considered dynamic constraints, poor smoothness of the feedrate profile, and reliance on non-open CNC interpolator. To overcome those deficiencies, this work proposes a highly-efficient dwell time algorithm under the dynamic constraints of machine tools. The method calculates the initial dwell time density (DTD) sequence through non-blind deconvolution algorithm, and provides the feasible set of DTD profiles based on trigonometric-spline model. And the DTD repairing tactics are developed based on a self-adaptive offset algorithm under confined feedrate and acceleration. Finally, a C1-continuous DTD profile satisfying dynamic constraints is generated. A real-time interpolator based on trigonometric-spline DTD profile is developed. The simulation results show that the proposed method generates a C1-continuous feedrate profile rigidly respecting dynamic constraints, and preserves the ideal dwell time gradient distribution, achieving a more ideal residual error with high computational efficiency compared with the previous methods. The comparative experiments demonstrate that the proposed method performs better in suppressing the multi-frequency errors compared with the previous methods, and achieves high computational efficiency. The algorithm is applicable to highly-precise and highly-efficient fabrication of large-aperture optical components.

Efficacy of neoadjuvant chemotherapy combined with prophylactic intraperitoneal hyperthermic chemotherapy for patients diagnosed with clinical T4 gastric cancer who underwent laparoscopic radical gastrectomy: a retrospective cohort study based on propensity score matching.

BACKGROUND: Clinical T4 (cT4) stage gastric cancer presents with frequent postoperative recurrence and poor prognosis. This study is to evaluate the oncological efficacy of laparoscopic radical total gastrectomy combined with postoperative prophylactic hyperthermic intraperitoneal chemotherapy (HIPEC) in patients with cT4N + M0 gastric cancer who received neoadjuvant chemotherapy. METHODS: We reviewed the clinicopathological data of 174 patients with clinical T4 gastric cancer who underwent neoadjuvant chemotherapy followed by laparoscopic radical total gastrectomy between June 2017 and December 2021. Among them, 142 were included in the non-HIPEC group, and 32 in the HIPEC group. Patients in both groups were paired based on propensity score in a 2:1 ratio to assess disparities in tumor recurrence and long-term survival. RESULTS: After matching, there were no significant differences in the clinicopathological data between the two groups. The peritoneum (16.1%) and distant organs (10.9%) were the most frequent locations for recurrence. Prior to matching, the recurrence rates were similar at all sites for both groups. Compared with those in the non-HIPEC cohort, the recurrence rates at all sites, the lung, and the peritoneum were notably lower in the HIPEC cohort. Prior to matching, the 3-year overall survival and disease-free survival rates were similar between the two groups; following matching, the HIPEC group exhibited notably greater survival rates than did the non-HIPEC group. The disparities in survival rates between the groups became even more pronounced after conducting a stratified analysis among patients with stage III disease. CONCLUSIONS: Neoadjuvant chemotherapy combined with prophylactic HIPEC after laparoscopic radical gastrectomy can effectively reduce the rate of peritoneal metastasis in patients with cT4N + M0 advanced gastric cancer and significantly improve the prognosis of such patients, which is of great clinical value.

Gas Phase Transformations in Carbon-11 Chemistry.

The short-lived positron-emitter carbon-11 (t1/2 = 20.4 min; ß+, 99.8%) is prominent for labeling tracers for use in biomedical research with positron emission tomography (PET). Carbon-11 is produced for this purpose with a cyclotron, nowadays almost exclusively by the 14N(p,α)11C nuclear reaction, either on nitrogen containing a low concentration of oxygen (0.1-0.5%) or hydrogen (~5%) to produce [11C]carbon dioxide or [11C]methane, respectively. These primary radioactive products can be produced in high yields and with high molar activities. However, only [11C]carbon dioxide has some utility for directly labeling PET tracers. Primary products are required to be converted rapidly and efficiently into secondary labeling synthons to provide versatile radiochemistry for labeling diverse tracer chemotypes at molecular positions of choice. This review surveys known gas phase transformations of carbon-11 and summarizes the important roles that many of these transformations now play for producing a broad range of labeling synthons in carbon-11 chemistry.

Gastric cancer peritoneal metastasis related signature predicts prognosis and sensitivity to immunotherapy in gastric cancer.

Gastric cancer peritoneal metastases (GCPM) is a leading cause of GC-related death. Early detection of GCPM is critical for improving the prognosis of advanced GC. Differentially expressed genes (DEGs) were identified in the GSE62254 database to distinguish between GCPM and non-GCPM. The gastric cancer peritoneal metastases signature (GCPMs) was developed using DEGs. We analysed the effectiveness of GCPMs as indicators for prognosis, chemotherapy, and immune therapy response in GC patients. Subsequently, we analysed the correlation between GCPMs and immune microenvironment as well as immune escape in GC patients. Random forest model and immunohistochemistry was utilized to identify the crucial genes that can aid in the diagnosis of GCPM. We identified five DEGs and utilized their expression to construct GCPMs. Patients with high GCPMs had a higher likelihood of a poor prognosis, while those with low GCPMs appeared to potentially benefit more from chemotherapy. GCPMs were a dependable marker for predicting the response to immunotherapy. Additionally, GCPMs was found to be significantly linked to stromal score and cancer-associated fibroblasts. SYNPO2 has been identified as the gene with the highest significance in the diagnosis of GCPM. Immunohistochemistry suggests that SYNPO2-positive expression in tumour cells, fibroblasts, inflammatory cell may be associated with promoting peritoneal metastasis in GC. GCPMs have shown to be a promising biomarker for predicting the prognosis and response of GC patients to chemotherapy and immunotherapy. The use of GCPMs for individual tumour evaluation may pave the way for personalized treatment for GC patients in the future.

Radiographical Evaluation of Tumor Immunosuppressive Microenvironment and Treatment Outcomes in Gastric Cancer: A Retrospective, Multicohort Study.

BACKGROUND: The tumor immunosuppressive microenvironment can influence treatment response and outcomes. A previously validated immunosuppression scoring system (ISS) assesses multiple immune checkpoints in gastric cancer (GC) using tissue-based assays. We aimed to develop a radiological signature for non-invasive assessment of ISS and treatment outcomes. METHODS: A total of 642 patients with resectable GC from three centers were divided into four cohorts. Radiomic features were extracted from portal venous-phase CT images of GC. A radiomic signature for predicting ISS (RISS) was constructed using the least absolute shrinkage and selection operator (LASSO) regression method. Moreover, we investigated the value of the RISS in predicting survival and chemotherapy response. RESULTS: The RISS, which consisted of 10 selected features, showed good discrimination of immunosuppressive status in three independent cohorts (area under the curve = 0.840, 0.809, and 0.843, respectively). Multivariate analysis revealed that the RISS was an independent prognostic factor for both disease-free survival (DFS) and overall survival (OS) in all cohorts (all p < 0.05). Further analysis revealed that stage II and III GC patients with low RISS exhibited a favorable response to adjuvant chemotherapy (OS: hazard ratio [HR] 0.407, 95% confidence interval [CI] 0.284-0.584); DFS: HR 0.395, 95% CI 0.275-0.568). Furthermore, the RISS could predict prognosis and select stage II and III GC patients who could benefit from adjuvant chemotherapy independent of microsatellite instability status and Epstein-Barr virus status. CONCLUSION: The new, non-invasive radiomic signature could effectively predict the immunosuppressive status and prognosis of GC. Moreover, the RISS could help identify stage II and III GC patients most likely to benefit from adjuvant chemotherapy and avoid overtreatment.

Synthesis and Evaluation of Fluorine-18 Labeled 2-Phenylquinoxaline Derivatives as Potential Tau Imaging Agents.

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 ß-amyloid plaques (Aß). 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 Aß. 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.

Which Staging System Is More Suitable for Gastric Neuroendocrine Cancer and Mixed Adenoneuroendocrine Carcinomas? A Multicenter Cohort Study.

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.

Multi-institutional development and validation of a nomogram to predict recurrence after curative resection of gastric neuroendocrine/mixed adenoneuroendocrine carcinoma.

OBJECTIVE: 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]. BACKGROUND: Among patients undergoing radical resection of gastric (MA)NEC, there is still a high tendency for relapse. METHODS: 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). RESULTS: 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 < 0.001), and there were still significant differences in stratified analysis of the TNM staging systems. The local recurrence rate (10.5% vs 2.6%) and distant recurrence rate (45.1% vs 22.6%) in HRG were significantly higher than those in LRG, especially in anastomotic recurrence (6.3% vs 2%), liver recurrence (20.7% vs 13.4%) and peritoneal metastasis (12.7% vs 2.6%). CONCLUSIONS: Compared with AJCC and ENETS TNM staging systems, the established novel validated nomogram had a significantly better prediction ability for DFS and recurrence patterns in patients with gastric (MA)NEC. It can also compensate for the shortcomings of existing AJCC and ENETS TNM staging in predicting individual recurrence risk.

Reappraise role of No. 10 lymphadenectomy for proximal gastric cancer in the era of minimal invasive surgery during total gastrectomy: a pooled analysis of 4 prospective trial.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Agaricus bisporus-Derived Glucosamine Hydrochloride Facilitates Skeletal Injury Repair through Bmp Signaling in Zebrafish Osteoporosis Model.

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.

Conditional survival and recurrence of remnant gastric cancer after surgical resection: A multi-institutional study.

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 < 0.001). Most recurrences (93.5%) occurred in the first 3 years after surgery. The American Joint Committee on Cancer (AJCC) stage was the only factor that affected recurrence. Time-dependent Cox regression showed that for both OS and DSS, after 4 years of survival, the common prognostic factors that were initially judged lost their ability to predict survival (P > 0.05). Time-dependent logistic regression analysis showed that the AJCC stage independently affected recurrence within 2 years after surgery (P < 0.05). A postoperative follow-up model was developed for RGC patients. In conclusion, 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, which may affect the design of future clinical trials.

Safety and feasibility of laparoscopic spleen-preserving No. 10 lymph node dissection for locally advanced upper third gastric cancer: a prospective, multicenter clinical trial.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSION: 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.

Epigenetic silenced miR-125a-5p could be self-activated through targeting Suv39H1 in gastric cancer.

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.

MicroRNA-329 inhibits cell proliferation and tumor growth while facilitates apoptosis via negative regulation of KDM1A 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.

Quinuclidine and DABCO Enhance the Radiofluorinations of 5-Substituted 2-Halopyridines.

Positron emission tomography (PET) is an important molecular imaging technique for medical diagnosis, biomedical research and drug development. PET tracers for molecular imaging contain ß+-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.

A multicenter study of using carbon nanoparticles to show sentinel lymph nodes in early gastric cancer.

BACKGROUND: Lymph node metastasis occurs in approximately 10% of early gastric cancer. Preoperative or intra-operative identification of lymph node metastasis in early gastric cancer is crucial for surgical planning. The purpose of this study was to evaluate the feasibility of using carbon nanoparticles to show sentinel lymph nodes (SLNs) in early gastric cancer. METHODS: A multicenter study was performed between July 2012 and November 2014. Ninety-one patients with early gastric cancer identified by preoperative endoscopic ultrasonography were recruited. One milliliter carbon nanoparticles suspension, which is approved by Chinese Food and Drug Administration, was endoscopically injected into the submucosal layer at four points around the site of the primary tumor 6-12 h before surgery. Laparoscopic radical resection with D2 lymphadenectomy was performed. SLNs were defined as nodes that were black-dyed by carbon nanoparticles in greater omentum and lesser omentum near gastric cancer. Lymph node status and SLNs accuracy were confirmed by pathological analysis. RESULTS: All patients had black-dyed SLNs lying in greater omentum and/or lesser omentum. SLNs were easily found under laparoscopy. The mean number of SLNs was 4 (range 1-9). Carbon nanoparticles were around cancer in specimen. After pathological analysis, 10 patients (10.99%) had lymph node metastasis in 91 patients with early gastric cancer. SLNs were positive in 9 cases and negative in 82 cases. In pathology, carbon nanoparticles were seen in lymphatic vessels, lymphoid sinus, and macrophages in SLNs. When SLNs were positive, cancer cells were seen in lymph nodes. The sensitivity, specificity, and accuracy of black-dyed SLNs in early gastric cancers were 90, 100, and 98.9 %, respectively. No patient had any side effects of carbon nanoparticles in this study. CONCLUSIONS: It is feasible to use carbon nanoparticles to show SLNs in early gastric cancer. Carbon nanoparticles suspension is safe for submucosal injection.

Exploration of the labeling of [11C]tubastatin A at the hydroxamic acid site with [11C]carbon monoxide.

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 (<5%) of [(11) C]1. Labeling was achieved in useful radiochemical yields (16.1 ± 5.6%, n = 4) through a two-step process based on Pd-mediated insertion of [(11)C]carbon monoxide between the aryl iodide (2) and p-nitrophenol to give the [(11)C]p-nitrophenyl ester ([(11)C]5), followed by ultrasound-assisted hydroxyaminolysis of the activated ester with excess hydroxylamine in a DMSO/THF mixture in the presence of a strong phosphazene base P1-t-Bu. However, success in labeling the hydroxamic acid group of [(11)C]tubastatin A was not transferable to the labeling of three other model hydroxamic acids.

New N-aryl-N'-(3-(substituted)phenyl)-N'-methylguanidines as leads to potential PET radioligands for imaging the open NMDA receptor.

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 (t1/2=20.4min). 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; Ki 36.7nM), 3'-trifluoromethyl (20; Ki 18.3nM) and 3'-methylthio (2; Ki 39.8nM) derivatives of N-1-naphthyl-N'-(phenyl)-N'-methylguanidine were identified as especially attractive leads for PET radioligand development.

A multi-center study of using carbon nanoparticles to track lymph node metastasis in T1-2 colorectal cancer.

BACKGROUND: 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. METHODS: 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. RESULTS: 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. CONCLUSIONS: 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.

Ligand-Based Virtual Screening as a Path to New Chemotypes for Candidate PET Radioligands for Imaging Tauopathies.

Ligand-based virtual screening (LBVS) has rarely been tested as a method for discovering new structural scaffolds for PET radioligand development. This study used LBVS to discover potential chemotype leads for developing radioligands for PET imaging of tauopathies. ZINC12, a free database of over 12 million commercially available compounds, was searched to discover novel scaffolds based on similarities to four query compounds. Thirteen high-ranking hits were purchased and assayed for their ability to compete against three tritiated radioligands at their distinct binding sites in Alzheimer's disease brain tissue. Three hits were 2-substituted 6-methoxy naphthalenes. Synthetic elaboration of this new chemotype yielded three new ligands (25, 26, and 28) with high affinity for the [3H]6 (flortaucipur) neurofibrillary tangle binding site. Compound 28 showed remarkably high affinity (Ki, 7 nM) and other desirable properties for a candidate PET radioligand, including low topological polar surface area, moderate computed log D, and amenability for labeling with carbon-11. LBVS appears to be uniquely valuable for discovering new chemotypes for candidate PET radioligands.