Heng Chen

Xijing University, 西荆, Shaanxi, China

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Publications (18)25.99 Total impact

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    ABSTRACT: The aim of this study was to investigate physiological factors that affect serum insulin levels and to establish insulin reference intervals for healthy Chinese Han adults. A total of 4401 subjects with normal glucose tolerance (NGT) were screened from 10,027 individuals in an epidemiological study. Based on the exclusion criteria, 2414 apparently healthy adults (healthy) were selected as reference individuals. Serum insulin levels of the reference individuals were measured at fasting, 30 min and 120 min after oral glucose tolerance test (OGTT). Significant correlations were found between serum insulin levels and physiological factors in healthy subjects, including body mass index (BMI), weight, systolic blood pressure (SBP), diastolic blood pressure (DBP), etc. (p < 0.05). No increase or decrease was found in age-dependent insulin levels by ANOVA (p > 0.05). There was also no substantial difference in fasting serum insulin levels between males and females (p > 0.05). However, we detected notable differences in serum insulin levels between males and females at 30 min (p < 0.01), which became more pronounced at 120 min (p < 0.001). According to our data, BMI/gender-related insulin reference intervals were defined by calculating 2.5th and 97.5th percentiles. The insulin reference intervals, determined after assessing the relationship between physiological factors and serum insulin levels in Chinese adults, will provide valuable information for physicians in their interpretation of insulin levels.
    Scandinavian Journal of Clinical and Laboratory Investigation 03/2015; 75(4):1-8. DOI:10.3109/00365513.2014.992947 · 2.01 Impact Factor
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    ABSTRACT: Islet autotransplantation (IAT) is a viable treatment for patients with severe chronic pancreatitis, this modality may prevent brittle diabetes mellitus after pancreatectomy. This systematic review and meta-analysis was performed to evaluated the outcomes of IAT after TP and discuss the factors that may affect the efficacy of this procedure. Methods: MEDLINE, Embase, Web of Science and the Cochrane Central Register of Controlled Trials (CENTRAL) were searched from 1977 to 30 April 2014. Cohort Studies reported patients with IAT after TP were included. The studies and data were identified and extracted by two reviewers independently. Data were analyzed using STATA 12.0 and Comprehensive Meta AnalysisV2 software. Random effects model, meta-regression analysis, sensitivity analysis and publication bias were conducted to improve the comprehens ive analysis. Results: Twelve studies reporting the outcomes of 677 patients were included in this review. The insulin independent rate for IAT after TP at last follow-up was 3.72 per 100 person-years (95% CI: 1.00-6.44). The 30-day mortality was 2.1% (95% CI: 1.2-3.8%). The mortality at last follow-up was 1.09 per 100 person-years (95% CI: 0.21-1.97). Factors associated with incidence density of insulin independence in univariate meta-regression analyses included IEQ/kgBW (P=0.026). Conclusions: Our systematic review suggests that IAT is a safe modality for patients with CP need to undergo TP. A significant number of patients will achieve insulin independence for a long time after receiving enough IEQ/kg.
    Endocrine Journal 01/2015; 62(3). DOI:10.1507/endocrj.EJ14-0510 · 2.02 Impact Factor
  • 01/2015; 713-715:934-937. DOI:10.4028/www.scientific.net/AMM.713-715.934
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    ABSTRACT: Abstract Objective: To investigate the protective effects of a pentadecapeptide of islet neogenesis-associated protein (INGAP-PP) on transplanted islets function. Methods: Islets were cultured in RPMI 1640 with or without INGAP-PP (10 μg/mL). After 24 h, the viability of the islets and glucose-stimulated insulin secretion (GSIS) were measured. The expression of genes B cell lymphoma/lewkmia2 (Bcl2) and protein kinase B (Akt) were detected by RT-PCR assay. Healthy rats transplanted with islets under the renal capsule were injected with INGAP-PP or saline in in the abdominal cavity. One week later, the expression of insulin nestin pancreatic (nestin) and duodenal homeobox 1 (Pdx1) and proliferating cell nuclear antigen (PCNA) in the transplanted islets were observed by immunohistochemistry. After that they were transplanted to the renal capsule of diabetic rats. Results: 1. The amount of insulin released was increased in co-cultured group in concentration of 16.7 mmol/L glucose, which was (185.00±20.01 μU/mL) vs. (58.67±17.03 μU/mL). Gene expression of Bcl2 (0.61±0.22 vs. 0.50±0.21) and Akt (1.12±0.19 vs. 0.94±0.16) in the co-cultured group were increased compared with that of the control group. Islets viability in the co-cultured group (683.9±7.08) was higher than that of control group (547.9±8.02). The stimulating index (SI) of the co-cultured group was also higher than that of the control group. 2. The group of islets under the renal capsule which were co-cultured and injected with INGAP-PP had the more nestin expression in the islets. Conclusions: The function of islet can be protected by the INGAP-PP, which will promote the viability, differentiation and regeneration of islet before transplantation. And it will be beneficial for the function of allograft after islets transplantation.
    Journal of pediatric endocrinology & metabolism: JPEM 08/2014; 27(11-12). DOI:10.1515/jpem-2014-0127 · 0.71 Impact Factor
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    ABSTRACT: In this paper, a new chaotic system is constructed. This system contains four parameters and two nonlinear terms. The fractal dimension and the heteroclinic orbit are analyzed in the system. Meanwhile, the circuit of the chaotic system is designed by using Mutisim software. The conclusion confirms the consistency of the numerical simulation and circuit. Because of the above properties, the proposed system has a wide application in such as weak signal detection secure communications and secure communications.
    07/2014; 986-987:1726-1729. DOI:10.4028/www.scientific.net/AMR.986-987.1726
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    ABSTRACT: In this paper, the directly driven wind turbine with permanent magnet synchronous generator (D-PMSG) is investigated, the mathematical model of which is built up. Also, the chaotic behaviors or limit cycle phenomena is demonstrated under certain working conditions or the parameters of the model having a certain range of values. A novel adaptive controller is designed based on the quasi-Lyapunov stability theory for fractional-order systems. Also, electronic circuits are designed to realize the controllers using Multisim. The simulation results demonstrate the effectiveness and realizable ness of the proposed methods, besides, the research results will be provided as theoretical references for the study of improving control performance.
    07/2014; 986-987:1039-1042. DOI:10.4028/www.scientific.net/AMR.986-987.1039
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    ABSTRACT: According to the requirements of the aircraft power supply equipment, the high voltage DC-DC power converter module is developed. In this paper, the HVDC (High Voltage DC-DC Converter) topology is studied. The starting circuit is designed based on the control chip TL3844. The components parameters are calculated. An overvoltage protection circuit and a current limiting protection circuit are designed to improve the stability of the system. At the same time voltage compensation circuit is designed to compensate the voltage.
    06/2014; 978:63-66. DOI:10.4028/www.scientific.net/AMR.978.63
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    ABSTRACT: In this paper, the dynamic motion of the wind turbine permanent magnet synchronous generator is studied. After the permanent magnet synchronous generator motion is analyzed, the system has a complex chaotic motion in some parameters condition. A controller is designed based on optimal control theory. The optimal controller is used to avoid PMSG chaos and ensure the system is stable. This controller is simple and easy to implement. The simulation results show the whole control system has the good performance. The wind turbine PMSG optimal controller can be used by the other researchers.
    03/2014; 543-547:1291-1295. DOI:10.4028/www.scientific.net/AMM.543-547.1291
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    ABSTRACT: The calibration wells laboratory is an important experimental system of petroleum logging instrument. There is a large of calibration wells information need manage, so it is very difficult to manage the calibration wells information. In this paper, computer information management system is applied to the calibration wells information management. It is necessary to manage the large of the calibration wells information. Because the calibration wells have the similar shape, it is difficult to detect the calibration wells in the laboratory. Therefore, the mobile phone platform and QR two-dimensional bar code technology are introduced to strengthen the management of calibration wells information. These will greatly improve the efficiency of management. The QR bar code and the zBar technology are used in the information system. The design of calibration wells group information management system is implemented based on QR code. The mobile platform is used to collect and display information. The experiments show the good performance of the information management systems.
    03/2014; 543-547:4284-4287. DOI:10.4028/www.scientific.net/AMM.543-547.4284
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    ABSTRACT: A remote monitoring system based on GPRS is designed to monitor the oil production in this paper. This system can help us to realize unmanned oil production. The system realizes data acquisition, transmission, storage and processing of oil wells production data. The system is mainly composed of the field monitoring terminal, wireless router and monitoring center etc. Through the GPRS wireless data transmission technology, we can realize the operation state monitoring and real-time monitoring of oil production and improve the efficiency of oil well monitoring. This system has the reliable information transmission, low cost, more automation and maintenance simple. The system can greatly improve the production management level.
    03/2014; 543-547:1001-1004. DOI:10.4028/www.scientific.net/AMM.543-547.1001
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    ABSTRACT: In this paper, infrared thermal wave NDT techniques are used for aircraft composites. After the infrared image is sharpened and the temperature field is analyzed, aircraft composite material defects can be diagnosed. Experiments show that the infrared NDT techniques can detect defects in aircraft composite image. Images and first-order differential image can be presented more clearly outline the process and temperature variations. Defect size and depth can also be measured. The best experiments are designed for different materials. After several experiments of the precise temperature calibration can be further studied. Defects can be interpreted intelligent.
    03/2014; 543-547:1018-1021. DOI:10.4028/www.scientific.net/AMM.543-547.1018
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    ABSTRACT: Follicular helper T (Tfh) cells exert an important role in autoimmune diseases. Whether it might be involved in type 1 diabetes (T1D) is unknown. Our aim was to investigate the role of Tfh cells in patients with T1D and the effect of anti-CD20 monoclonal antibody (rituximab) on Tfh cells from T1D patients. Fifty-four patients with T1D and 37 healthy controls were enrolled in the current study. 20 of those patients were treated with rituximab. The frequencies of circulating CD4(+)CXCR5(+)ICOS(+)T cells were analyzed by flow cytometry. The serum autoantibodies were detected by radioligand assay. The levels of IL-21, IL-6 and BCL-6 were assessed using ELISA and/or real-time PCR. Increased frequencies of circulating Tfh cells together with enhanced expression of IL-21 were detected in patients. The correlation between the frequencies of circulating Tfh cells and the serum autoantibodies or C-peptide level was comfirmed. After rituximab therapy, follow-up analysis demonstrated that the frequencies of circulating Tfh cell and serum IA2A were decreased. The levels of IL-21, IL-6 and Bcl-6 mRNA were decreased after treatment. Furthermore, beta cell function in 10 of 20 patients was improved. These data indicate Tfh cells may participate in the T1D-relatede immune responses and B cells might play a role in the development of Tfh responses in the disease progression.
    PLoS ONE 11/2013; 8(11):e79858. DOI:10.1371/journal.pone.0079858 · 3.53 Impact Factor
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    ABSTRACT: Type 1 diabetes (T1D) is perceived as an autoimmune disease caused by T cell-mediated destruction of the insulin-producing pancreatic β cells. However, the number of inflammatory T cells in blood, as well as the relative importance of each cell type is unclear. Forty-two patients with T1D and 30 controls were enrolled. Circulating primary CD4(+) or CD8(+) T cells were quantified with 5-color flow cytometry. Serum IL-22 and IL-17 levels were examined by ELISA. Serum autoantibodies were measured by radio-binding assays, using (35)S-labeled glutamic acid decarboxylase-65 (GAD65), protein tyrosine phosphatase-2 (IA-2), and zinc transporter 8 (ZnT8). Th17-Th22 and Tc1-Tc17 were significantly elevated in patients with T1D compared to control subjects, while there were no significant differences in Th1 cells. The levels of these T cells in different stages of T1D were investigated. Th22 cells showed a positive correlation with Th17 cells in T1D patients. However, we did not find any correlation between IL-17 and IL-22 in sera. Autoantibodies were not significantly different between patients with early T1D and those who have had it for a longer duration. This study indicates that Th22 may contribute to the pathogenesis of T1D. Blockade of Th22 cells might be of clinical profit in T1D patients.
    Endocrine 08/2013; 46(1). DOI:10.1007/s12020-013-0030-z · 3.53 Impact Factor
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    ABSTRACT: BACKGROUND AND AIM: Nonalcoholic fatty liver disease (NAFLD) is strongly associated with obesity, hyperlipidemia, and type 2 diabetes mellitus. Several studies have found that fat mass and the obesity-associated (FTO) gene is linked to obesity. The aim of this work is to investigate the expression and function of FTO in liver with lipid metabolism diseases. METHODS: We investigated the basal FTO expression in an NAFLD rat model and compared it with control subjects. The function of FTO in lipid metabolism was further studied in L02 cells through overexpression experiments. RESULTS: A significant increase in FTO mRNA and protein levels was found in the NAFLD group. In addition, the FTO levels were positively associated with malondialdehyde and superoxide dismutase concentrations. FTO overexpression in L02 cells enhanced lipogenesis and oxidative stress. CONCLUSIONS: This study demonstrates that increased FTO levels in the liver are involved in oxidative stress and lipid deposition, which characterize NAFLD.
    Digestive Diseases and Sciences 01/2013; 58(4). DOI:10.1007/s10620-012-2516-6 · 2.55 Impact Factor
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    ABSTRACT: Identification of cognate peptides recognized by human leucocyte antigen (HLA)/T cell receptor (TCR) complex provides insight into the pathogenic process of type 1 diabetes (T1D). We hypothesize that HLA-binding assays alone are inadequate metrics for the affinity of peptides. Zinc transporter-8 (ZnT8) has emerged in recent years as a novel, major, human autoantigen. Therefore, we aim to identify the HLA-A2-restricted ZnT8 epitopes using both binding and dissociation assays. HLA class I peptide affinity algorithms were used to predict candidate ZnT8 peptides that bind to HLA-A2. We analyzed 15 reported epitopes of seven β-cell candidate autoantigens and eight predicted candidate ZnT8 peptides using binding and dissociation assays. Using IFN-γ ELISpot assay, we tested peripheral blood mononuclear cells (PBMCs) from recent-onset T1D patients and healthy controls for reactivity to seven reported epitopes and eight candidate ZnT8 peptides directly ex vivo. We found five of seven recently reported epitopes in Chinese T1D patients. Of the eight predicted ZnT8 peptides, ZnT8(153-161) had a strong binding affinity and the lowest dissociation rate to HLA-A*0201. We identified it as a novel HLA-A*0201-restricted T-cell epitope in three of eight T1D patients. We conclude that ZnT8(153-161) is a novel HLA-A*0201-restricted T-cell epitope. We did not observe a significant correlation (P = 0.3, R = - 0.5) between cytotoxic T cell (CTL) response and peptide/HLA*0201 complex stability. However, selection of peptides based on affinity and their dissociation rate may be helpful for the identification of candidate CTL epitopes. Thus, we can minimize the number of experiments for the identification of T-cell epitopes from interesting antigens.
    Autoimmunity 03/2012; 45(2):176-85. DOI:10.3109/08916934.2011.622014 · 2.75 Impact Factor
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    ABSTRACT: The evaluation of susceptibility loci is an important addition to the current predictive and screening models in type 1 diabetes of Chinese Han population. Therefore, the aim of this study is to provide evidence for the association between type 1 diabetes and two polymorphisms (rs3747517, rs1990760) from interferon induced with helicase C domain 1 (IFIH1). Here, 464 Type 1 diabetes patients and 465 control subjects were genotyped for these 2 polymorphisms. The results indicated that the allelic frequencies of rs3747517 revealed a strong association with type 1 diabetes risk (P < 0.001); yet, no significant association was observed on rs1990760(P = 0.76). Furthermore, IFIH1 rs3747517 polymorphism had no influence on the positive rates of pancreatic auto-antibodies, and both of the polymorphisms had no interaction with HLA class I-linked risk or phenotypes. In conclusion, IFIH1 rs3747517, but not rs1990760 polymorphism, plays an important role in type 1 diabetes risk in Chinese Han population.
    Autoimmunity 11/2011; 45(3):226-32. DOI:10.3109/08916934.2011.633134 · 2.75 Impact Factor
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    ABSTRACT: To reveal the aetiology of diabetes, the relationships between the islet autoantibodies, human leukocyte antigen (HLA)-A and DRB1 genotypes in the Chinese patients with type l diabetes (T1D) were investigated in our study. In the cross-sectional and case-control study, peripheral blood samples were collected from 600 T1D patients and 102 healthy controls. The genetic polymorphisms of HLA-A and DRB1 are examined with polymerase chain reaction-sequence oligonucleotide probe method. The zinc transporter 8 antibody (ZnT8A), glutamic acid decarboxylase antibody (GADA) and protein-tyrosine-phosphatase-2 autoantibody (IA2A) were detected by radioligand assay. The A*2402, DRB1*0301, DRB1*0405 and DRB1*0901 alleles, and A*1101-DRB1*0901, A*2402-DRB1*0405 and A*2402-DRB1*0901 haplotypes were associated with T1D (all p<0.05). The positive rates of ZnT8A in patients carried DRB1*0901, IA2A in patients carried DRB1*0405 and A*1101-DRB1*0901 and GADA in patients carried DRB1*0901 and A*2402-DRB1*0901 were significantly higher than those not carried (p<0.05). HLA-DRB1*0901 was the independent risk factor of positive antibody in T1D patients. In addition, higher body mass index is also related with the loss of islet function besides high-risk HLA gene and islet autoantibody (p<0.05). The discordant association of autoantibodies with high-risk HLA gene may indicate the different immunology mechanisms of those autoantibodies. And metabolic burden resulting from overweight may accelerate apoptosis of beta cells.
    Diabetes/Metabolism Research and Reviews 11/2011; 27(8):899-905. DOI:10.1002/dmrr.1270 · 3.59 Impact Factor
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    ABSTRACT: To investigate the association of solute carrier family 30 member 8 (SLC30A8) rs13266634 C/T polymorphism with type 2 diabetes (T2DM), impaired glucose tolerance (IGT), and type 1 diabetes (T1DM). We searched all the publications about the association between SLC30A8 and diabetes from PubMed, and evaluated the association between SLC30A8 rs13266634 C/T polymorphism and T2DM, IGT and T1DM, respectively, by meta-analysis of all the validated studies. Allelic and genotypic comparisons between cases and controls were evaluated. Thirty six studies were included in the meta-analysis: 31 studies were analysed for rs13266634 C/T polymorphism with T2DM, 3 studies with IGT and 4 studies with T1DM. The pooled odds ratios (ORs) for allelic and genotypic comparisons (including additive model, co-dominant model, dominant model and recessive model) showed that rs13266634 C/T polymorphism was significantly associated with increased T2DM risk: OR=1.15, 95% confidence interval (CI)=1.13-1.17, P<0.001, P(heterogeneity)=0.041, OR=1.34, 95% CI=1.26-1.41, P<0.001, P(heterogeneity)=0.908, OR=1.20, 95% CI=1.16-1.24, P<0.001, P(heterogeneity)=0.699, and OR=1.23, 95% CI=1.17-1.30, P<0.001, P(heterogeneity)=0.801, respectively. In subgroup analyses, we found that rs13266634 C/T polymorphism was associated with T2DM risk both in Asian and European subgroup (P<0.001), but not in African (P>0.05). And the pooled odds ratio (OR) for allelic frequency comparison showed that rs13266634 C/T polymorphism was also significantly associated with IGT: OR=1.15, 95% CI=1.06-1.26, P<0.001, P(heterogeneity)=0.364. Meanwhile, our meta-analysis did not suggest that rs13266634 C/T polymorphism was associated with T1DM risk (P>0.05): OR=1.02, 95% CI=0.98-1.06, P=0.328, P(heterogeneity)=0.488 for allelic frequency comparison. Our meta-analysis results revealed the significant association between rs13266634 C/T polymorphism and T2DM and IGT, but did not support the association between this polymorphism and T1DM.
    Diabetes research and clinical practice 12/2010; 91(2):195-202. DOI:10.1016/j.diabres.2010.11.012 · 2.54 Impact Factor