Publications by authors named "Yuanjia Chen"

Plant and microbially derived carbon (C) are the two major sources of soil organic carbon (SOC), and their ratio impacts SOC composition, accumulation, stability, and turnover. The contributions of and the key factors defining the plant and microbial C in SOC with grassland patches are not well known. Here, we aim to address this issue by analyzing lignin phenols, amino sugars, glomalin-related soil proteins (GRSP), enzyme activities, particulate organic carbon (POC), and mineral-associated organic carbon (MAOC).

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Vegetation restoration can effectively enhance soil quality and soil organic carbon (SOC) sequestration. In this study, the distribution characteristics of soil nutrients and SOC along soil profile (0-100 cm), and their responses to restoration years (16, 28, 38 years) were studied in plantations in the southern mountainous area of Ningxia, compared with cropland and natural grassland. The results showed that: 1) the contents of SOC, soil total nitrogen (TN), total phosphorus (TP), particulate organic carbon (POC), mineral-associated organic carbon (MAOC) and the proportion of particulate organic carbon to total organic carbon (POC/SOC) all decreased with increasing soil depth.

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Background: There have been few studies on the role of autophagy in pancreatic neuroendocrine tumours (PNETs). SQSTM1/p62 (also called Sequestosome 1) is a potential autophagy regulator, and its biological roles and clinical significance in PNETs remain poorly understood.

Purpose: The purpose of this study was to evaluate the clinical significance of SQSTM1/p62 in human PNET specimens and to evaluate its potential value as a therapeutic target by studying its biological function in PNET cell lines.

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Background: Fibroblasts, especially cancer-associated fibroblasts (CAFs), represent the predominant stromal cell population in the tumor microenvironment and have an important function in tumorigenesis by interacting with tumor cells. However, their interaction remains elusive in an inflammatory tumor microenvironment induced by Helicobacter pylori (H. pylori).

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Background: Gastric cancer (GC) is a common malignant tumor with high incidence and mortality rates globally, especially in East Asian countries. () infection is a significant and independent risk factor for GC. However, its underlying mechanism of action is not fully understood.

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A robust method using HPLC-UV was developed to improve the accuracy and repeatability of a quantitative method to detect 5 nucleotides (cytidine-monophosphate, uridine monophosphate, adenosine monophosphate, guanine monophosphate, and inosine monophosphate) in infant formulas. The results showed that efficient separation could not be achieved without strict conditions. The proposed method displayed a strong linear relationship (R > 0.

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Objective: The clinical significance of the YY1 gene mutation and expression in pancreatic neuroendocrine tumors (PNETs) remains unknown. Therefore, this study aimed to comprehensively analyze the somatic mutation of YY1 in the different subtypes of PNETs.

Methods: A total of 143 PNETs were assessed by Sanger sequencing to identify the somatic mutation of YY1 gene in various subtypes of PNETs.

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A rapid, low-cost, and selective method for simultaneous and direct determination of maneb group residues (containing ethylenebis and propylenebis dithiocarbamates) in fruit by liquid chromatography coupled to tandem mass spectrometry was developed and validated in the current study. The results showed the maneb group could be melt and stabilized by 5 v% ethylenediamine for 60 days keeping in conventional refrigerators, in which a stable and ionizable pentadentate ligand complex was considered to be formed by the bidentate diamine and sulfhydryl followed by Density Functional Theory calculation. The validated method showed a sensitive quantification limits (0.

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Background: Insulinoma is a subtype of pancreatic neuroendocrine tumors. Many patients with insulinoma are obese due to frequent food intake. Ghrelin is associated with obesity and blood levels of insulin.

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Background: Pancreatic neuroendocrine tumors (pNET) are rare and heterogeneous. New biomarkers are needed for better predicting the prognosis and for providing individualized treatment. Versican (VCAN) plays an important role in tumorigenesis.

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Background: The neuronal intermediate filament alpha-internexin (α-internexin) is a cytoskeleton protein which is involved in the tumor initiation and progression. In this study, we examined the expression and prognosis value of α-internexin in gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs).

Methods: α-internexin was detected with immunohistochemical staining in 286 tumor specimens from patients with GEP-NENs.

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Aberrant blood vessel formation and hemorrhage may contribute to tumor progression and are potential targets in the treatment of several types of cancer. Pancreatic neuroendocrine tumors (PNETs) are highly vascularized, particularly when they are well-differentiated. However, the process of vascularization and endothelial cell detachment in PNETs is poorly understood.

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Background: Representative data on the gastroenteropancreatic neuroendocrine neoplasms (GEP-NENs) in Asian patients is rare, especially in China. This study aims to create a GEP-NENs profile of Chinese patients.

Methods: This was a hospital-based, nation-wide, and multi-center 10-year (2001-2010) retrospective study which collected GEP-NEN patients' information in tertiary referral hospitals.

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Prognostic biomarkers for the pancreatic neuroendocrine tumors are needed. Proteomic study on insulinoma has been rarely reported. We identified the differential expression of proteins between insulinoma and their paired tissues by proteomic analysis, and evaluated the prognostic significance of specific proteins in pancreatic neuroendocrine tumors including insulinoma.

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Polypyrimidine tract-binding protein 1 (PTBP1) involving in almost all steps of mRNA regulation including alternative splicing metabolism during tumorigenesis due to its RNA-binding activity. Initially, we found that high expressed PTBP1 and poor prognosis was interrelated in colorectal cancer (CRC) patients with stages II and III CRC, which widely different in prognosis and treatment, by immunohistochemistry. PTBP1 was also upregulated in colon cancer cell lines.

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Objective: The aim of the study was to address the origin and natural history of malignant insulinoma.

Methods: Retrospective review of medical records of patients diagnosed with insulinoma at Cedars-Sinai Medical Center between 2000 and 2015 was conducted. Hormonal expression in tumor specimens was examined by immunostaining.

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Gastrointestinal neuroendocrine tumors are a group of highly heterogeneous tumors. Their incidences have increased in the Western countries as well as in Asia for years. In recent years, predominant progression has been made in the basic and translational studies on gastrointestinal neuroendocrine tumors.

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The presentation, pathology, and prognosis of pancreatic neuroendocrine tumors (PNETs) in Asian patients have not been studied in large cohorts. We hypothesized that the clinicopathological features of PNETs of Chinese patients might be different from those of US patients. The objectives of this study were to address whether PNETs in Chinese patients exhibit unique clinicopathological features and natural history, and can be graded and staged using the WHO/ENETS criteria.

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The cells of origin of pancreatic gastrinomas remain an enigma, since no gastrin-expressing cells are found in the normal adult pancreas. It was proposed that the cellular origin of pancreatic gastrinomas may come from either the pancreatic cells themselves or gastrin-expressing cells which have migrated from the duodenum. In the current study, we further characterized previously described transient pancreatic gastrin-expressing cells using cell lineage tracing in a pan-pancreatic progenitor and a pancreatic endocrine progenitor model.

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O(6)-methylguanine-DNA methyltransferase (MGMT) is a widespread DNA repair enzyme defending against mutation caused by guanine O(6)-alkylating agents. Until now, we know only little about the expression of MGMT in gastroenteropancreatic neuroendocrine neoplasm (GEP-NEN). To study the expression of MGMT and its clinical significance in GEP-NEN, 174 specimens of GEP-NEN were examined, of which 152 specimens came from The First Affiliated Hospital, Sun Yat-sen University during October 1995 to November 2013, 22 specimens came from Peking Union Medical College Hospital during September 2004 to April 2010.

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Background: Pancreatic neuroendocrine tumors (PNETs) are a group of rare tumors. Chromogranin A (CgA) was considered as the most practical and useful serum tumor marker in PNET patients. But peripheral blood levels of CgA are not routinely tested in Chinese patients with PNETs.

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Purpose: We aimed to test whether α-internexin could be a molecular biomarker of tumor aggressiveness and prognosis in pancreatic neuroendocrine tumors (PNETs).

Patients And Methods: Using immunohistochemical staining and Western blot, we detected the expression of α-internexin in 350 tumors from 343 patients, of whom 257 were followed up. Methylation of α-internexin promoter was examined by bisulfite sequencing to identify the crucial region that determines gene expression.

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Cytoplasmic poly(A) binding protein 4 (PABPC4) is an RNA-processing protein that plays an important role in the regulation of gene expression. The aim of this study was to investigate the expression pattern and identify the potential clinical significance of PABPC4 in colorectal cancer. Immunohistochemical analysis revealed that 26.

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Previous studies have shown that S100P contributes to the development of a number of tumors. However, its prognostic significance in colorectal cancer (CRC) has not been demonstrated. This study aimed to confirm the expression of S100P in colorectal cancer as well as the epigenetic mechanism underlying its gene expression, and to demonstrate whether S100P could be used to predict prognosis as a biomarker.

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