Chao Chen

Fudan University, Shanghai, Shanghai Shi, China

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Publications (78)142.53 Total impact

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  • Experimental and therapeutic medicine 06/2015; DOI:10.3892/etm.2015.2554 · 0.94 Impact Factor
  • Mei Lyu · Xinzhu Lin · Chao Chen
    Zhonghua er ke za zhi. Chinese journal of pediatrics 05/2015; 53(5):383-4.
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    ABSTRACT: Phenylalanine, which is an essential aromatic amino acid, is either used for protein synthesis or irreversibly hydroxylated to tyrosine. The provision of optimal amounts of dietary phenylalanine is not only important for growth and development but might also influence catecholamine synthesis and release rates. The current recommended aromatic amino acid requirement for infants aged 0-6 mo is based on the amino acid content of human milk. We quantified the requirements for phenylalanine in the presence of excess tyrosine (166 or 177 mg/kg per day for term and preterm infants, respectively) for term and preterm neonates by using the indicator amino acid oxidation method with l-[1-(13)C]lysine 2HCl as an indicator. Hence, we determined the minimum obligatory phenylalanine requirement. Fully enterally fed term and preterm infants received randomly graded amounts of phenylalanine (5-177 mg/kg per day) as part of an elemental formula. Data are expressed as means ± SDs. Twenty term (birth weight: 3.19 ± 0.34 kg; gestational age: 38.9 ± 1 wk) and 16 preterm (birth weight: 1.75 ± 0.17 kg; gestational age: 32.5 ± 0.6 wk) Asian infants participated at a postnatal age of 17 ± 8 d. In total, 44 studies were performed. The minimum obligatory phenylalanine requirement was 58 mg/kg per day (95% CI: 38-78 mg/kg per day) and 80 mg/kg per day (95% CI: 40-119 mg/kg per day) for term and preterm infants, respectively. The determined mean phenylalanine-requirement estimates are lower than the contents of term and preterm formulas currently on the market. This trial was registered at www.trialregister.nl as NTR1610. © 2015 American Society for Nutrition.
    American Journal of Clinical Nutrition 04/2015; 101(6). DOI:10.3945/ajcn.114.089664 · 6.92 Impact Factor
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    ABSTRACT: Hypomyelination is the major cause of neurodevelopmental deficits that are associated with perinatal white matter injury. Chondroitin sulfate proteoglycans (CSPGs) are known to exert inhibitory effects on the migration and differentiation of oligodendrocytes (OLs). However, few studies describe the roles of CSPGs in myelination by OLs and the cognitive dysfunction (CD) that follows perinatal white matter injury. Here, we examined the alterations in the expression of CSPGs and their functional impact on the maturation of OLs and myelination in a neonatal rat model of hypoxic-ischemic (HI) brain injury. Three-day-old Sprague-Dawley (SD) rats underwent a right common carotid artery ligation and were exposed to hypoxia (6% oxygen for 2.5h). Rats were given cABC via an intracerebroventricular injection to digest CSPGs. Animals were sacrificed at 7, 14, 28 and 56days after HI injury and the accompanying surgical procedure. We found that the expression of CSPGs was significantly up-regulated in the cortical regions surrounding the white matter after HI injury. cABC successfully degraded CSPGs in the rats that received cABC. Immunostaining showed decreased expression of the pre-oligodendrocyte marker O4 in the cingulum, external capsule (EC) and corpus callosum (CC) in HI+cABC rats compared to HI rats. However HI+cABC rats exhibited greater maturation of OLs than did HI rats, with increased expression of O1 and myelin basic protein (MBP) in the white matter. Furthermore, using electron microscopy, we demonstrated that myelin formation was enhanced in HI+cABC rats, which had an increased number of myelinated axons and decreased G-ratios of myelin compared to HI rats. Finally, HI+cABC rats performed better in the Morris water maze task than HI rats, which indicates an improvement in cognitive ability. Our results suggest that CSPGs inhibit both the maturation of OLs and the process of myelination after neonatal HI brain injury. The data also raise the possibility that modifying CSPGs may repair this type of lesion associated with demyelination. Copyright © 2015. Published by Elsevier Inc.
    Experimental Neurology 04/2015; 269. DOI:10.1016/j.expneurol.2015.03.026 · 4.62 Impact Factor
  • Journal of microbiology, immunology, and infection = Wei mian yu gan ran za zhi 04/2015; 48(2):S48. DOI:10.1016/j.jmii.2015.02.089 · 2.08 Impact Factor
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    ABSTRACT: Few data are available on central-line associated bloodstream infections (CLABSIs) in Chinese neonatal intensive care units (NICUs). The aims of this study were to characterize CLABSIs among neonates in a Chinese NICU and evaluate the impact of a multifaceted evidence-based practice for improving quality program to decrease CLABSI. We conducted a prospective before-after intervention study with a 1-year follow-up among patients with central lines at the NICU of the Children's Hospital of Fudan University between January 2008 and December 2010. The study was conducted in 3 phases: before, during, and after the intervention. A multifaceted infection control program was introduced in phase 2 with successive surveillance. CLABSIs were prospectively monitored and compared. A total of 171 patients with central lines (CLs) were observed; 29 of them developed CLABSI corresponding to 7.35 per 1,000 catheter days, with a CL utilization ratio of 37.9%. Overall CLABSI rate decreased gradually from 16.7 per 1,000 CL days in phase 1 to 7.6 per 1,000 CL days in phase 2 (P = .08) to 5.2 per 1,000 CL days in phase 3 (P < .01). Gram-negative bacterium (54.5%) was the predominant pathogen in CLABSIs. A multifaceted infection control program is effective in reducing the CLABSI rate among neonates. Such interventions could be extended to other resource-limited countries. Copyright © 2015 Association for Professionals in Infection Control and Epidemiology, Inc. Published by Elsevier Inc. All rights reserved.
    American Journal of Infection Control 03/2015; 43(3):275-9. DOI:10.1016/j.ajic.2014.12.001 · 2.33 Impact Factor
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    ABSTRACT: Since 1986, the reference of birth weight for gestational age has not been updated. The aim of this study was to set up Chinese neonatal network to investigate the current situation of birth weight in China, especially preterm birth weight, to develop the new reference for birth weight for gestational age and birth weight curve. A nationwide neonatology network was established in China. This survey was carried out in 63 hospitals of 23 provinces, municipalities and autonomous regions. We continuously collected the information of live births in participating hospitals during the study period of 2011-2014. Data describing birth weight and gestational age were collected prospectively. Newborn's birth weight was measured by electronic scale within 2 hours after birth when baby was undressed. The evaluation of gestational age was based on the combination of mother's last menstrual period, ultrasound in first trimester and gestational age estimation by gestational age scoring system. the growth curve was drawn by using LMSP method, which was conducted in GAMLSS 1.9-4 software package in R software 2.11.1. A total of 159 334 newborn infants were enrolled in this study. There were 84 447 male and 74 907 female. The mean birth weight was (3 232 ± 555) g, the mean birth weight of male newborn was (3 271 ± 576) g, the mean weight of female newborn was (3 188 ± 528) g. The test of the variables' distribution suggested that the distribution of gestational age and birth weight did not fit the normal distribution, the optimal distribution for them was BCT distribution. The Q-Q plot test and worm plot test suggested that this curve fitted the distribution optimally. The male and female neonatal birth weight curve was developed using the same method. Using GAMLSS method to establish nationwide neonatal birth weight curve, and the first time to update the birth weight reference in recent 28 years.
    Zhonghua er ke za zhi. Chinese journal of pediatrics 02/2015; 53(2):97-103.
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    ABSTRACT: TLR insufficiency increases newborn's susceptibility to infectious disease. The peripheral blood of four premature births has been collected weekly from the 28(th) gestational week (GW) until maturity at 36(th) GW. Microarray assays were used to derive dynamic follow-up data of TLR1-10 and other TLR signaling pathway associated factor changes. The follow-up results showed that the transcription level of TLR1 increased at the 36(th), TLR 3 decreased at the 33(rd) and TLR7 increased at the 34(th) GW significantly, whereas NFkB and its activator TBK1 were highest transcribed in the 28(th) and 32(nd) GW. Low TLR4 transcription in addition to late MD-2 maturation (33(rd) GW) indicated a lack of defense mechanisms against bacterial infections in preterm births particular in the first weeks after birth. Late transcriptional enhancements of TLR1 and MYD88 (35(th) week) as well as β 2 microglobulin (35(th) GW) also indicated a weak immune system in the early maturation stages. The transcription levels of TLR1, 3, 7 and the signaling pathway associated cofactors were different transcribed during the 28(th) and 36(th) GWs of the premature newborns. In the early stage after preterm birth, beside peak transcriptions of NFkB and TBK1, the immune system is not fully developed and maturation takes place mainly between the 33th and 35(th) GW.
    International Journal of Clinical and Experimental Medicine 01/2015; 8(3):4108-14. · 1.42 Impact Factor
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    ABSTRACT: Low birth weight is associated with an increased risk of adverse outcomes in many diseases in adult life. We investigated the expression of IGF-II and the status of differentially methylated regions (DMR) in small for gestational age (SGA) infants after birth. Plasma IGF-II, IGF-II receptor (IGF2R), IGF-I, and IGF-binding protein 3 (IGFBP3) levels were measured after birth in 150 newborn infants. These included 30 term appropriate for gestational age (AGA), 30 term SGA, 30 term large for gestational age (LGA), 30 preterm AGA, and 30 preterm SGA infants. Plasma IGF-II levels after birth were lower in both term SGA (435.1±33.82 vs. 620.4±44.79, p=0.002) and LGA infants (483.7±33.8 vs. 620.42±44.79, p=0.018) than in term AGA infants. The expression of IGF-II was associated with birth weight and expressed at high levels, which suggests that IGF-II may continue to play an important role after birth.
    Journal of pediatric endocrinology & metabolism: JPEM 12/2014; 28(5-6). DOI:10.1515/jpem-2014-0269 · 0.71 Impact Factor
  • Weiwei Lin · Chao Chen
    Zhonghua er ke za zhi. Chinese journal of pediatrics 10/2014; 52(10):763-6.
  • Bi Ze · Chao Chen
    Zhonghua er ke za zhi. Chinese journal of pediatrics 10/2014; 52(10):760-3.
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    ABSTRACT: Objectives: To investigate plasma ghrelin and obestatin levels, and ghrelin/obestatin prepropeptide gene polymorphisms, in sequentially enrolled small for gestational age (SGA) infants. Methods: Neonates were sequentially enrolled into this study and were then subdivided into different groups, according to different study aims and availability of study materials. Consequently, plasma ghrelin and obestatin levels were measured in term SGA, term appropriate for gestational age (AGA), term large for gestational age (LGA), preterm SGA and preterm AGA neonates. Levels of both peptides were also measured in AGA infants of different gestational ages, and in term AGA neonates at different days following birth. Three ghrelin/obestatin prepropeptide gene single nucleotide polymorphisms (SNPs), Arg51Gln, Leu72Met, and Gln90Leu, were measured in neonates. Results: The study involved a total cohort of 581neonates. Out of 150 neonates (30 term AGA, 30 term SGA, 30 term LGA, 30 preterm AGA, and 30 preterm SGA), plasma obestatin levels were significantly higher in term SGA versus term LGA neonates (0.21 +/- 0.02 ng/ml versus 0.17 +/- 0.01 ng/ml, respectively). Out of a wider cohort, there were no significant differences in genotypes and allele frequencies of Arg51Gln, Leu72Met, and Gln90Leu SNPs between term SGA and AGA neonates, or between preterm SGA and AGA neonates. Conclusions: Ghrelin/obestatin prepropeptide polymorphisms were not found to be associated with SGA status in neonates; however, ghrelin and obestatin levels may be involved in growth and development. Further studies are required to understand the relationship between ghrelin, obestatin and prenatal development.
    The Journal of international medical research 09/2014; 42(6). DOI:10.1177/0300060514533525 · 1.10 Impact Factor
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    ABSTRACT: Background Human toll-like receptor 4 (TLR4) is an important receptor in innate immunity, particularly against gram-negative bacterial infection (GNBI). In our study, we evaluated associations of TLR4 single nucleotide polymorphisms (SNPs) with GNBI in Han Chinese neonates. Patients and Methods Polymorphisms in TLR4 were genotyped in 201 neonates with GNBI and 279 gestational age and birth weight-matched controls without GNBI. Polymorphism analyses were applied to allele frequencies of the detected TLR4 SNPs and their associations with various clinical entities, including premature birth and GNBI were assessed. Results A total of six SNPs with more than 5% frequency were found in several promoter sequences, including rs10759931, rs2737190, rs10116253, rs10983755, rs1927914, and rs10759932. Mutation allele frequencies ranged from 23 to 41%. There were no SNPs with a frequency greater than 5% in exon analyses. Allele G rs2737190 mutations and GGCGGC haplotypes were more frequent among preterm GNBI neonates (odds ratio [OR], 1.32; 95% confidence interval [CI], 1.02-1.71 and OR, 1.89; 95% CI, 1.19-3.00, respectively). No specific alleles or haplotypes were associated with GNBI status among term neonates. Conclusion In this study population of Han Chinese, there was a significant association between an ethnical unique SNP in the TLR4 promoter region and preterm neonatal GNBIs.
    American Journal of Perinatology 09/2014; 32(04). DOI:10.1055/s-0034-1387929 · 1.60 Impact Factor
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    ABSTRACT: Objectives: Tryptophan not only is an amino acid essential to protein synthesis but also serves as a precursor in 2 important metabolic pathways: the serotonin and the kynurenine pathways. Tryptophan is related to sleeping patterns. The objective of the present study was to determine the tryptophan requirement of term infants using the indicator amino acid oxidation (IAAO) method with L-[1-C-13] phenylalanine as the indicator. Methods: Enterally fed infants were randomly assigned to tryptophan intakes ranging from 0.5 to 73 mg . kg(-1) . day(-1) as part of an elemental diet. After 1-day adaptation to the test diet, [C-13]bicarbonate and L-[1-C-13]phenylalanine tracers were given enterally. Breath samples were collected at baseline and during isotopic plateaus. The mean tryptophan requirement was determined by using the biphasic linear regression crossover analysis on the fraction of 13 CO2 recovery from L-[1-C-13]phenylalanine oxidation ((FCO2)-C-13). Data are presented as mean +/- standard deviation. Results: A total of 30 term neonates (gestational age 39 +/- 1 weeks) were studied at 9 +/- 4 days. (FCO2)-C-13 decreased until a tryptophan intake of 15 mg . kg(-1) . day(-1); additional increases in tryptophan intake did not affect F-13 CO2. Mean requirement was determined to be 15 mg . kg(-1) . day(-1). Conclusions: The mean tryptophan requirement for elemental formula-fed term infants is 15 mg .kg(-1) . day(-1). This requirement is lower than the present recommended intake of 29 mg . kg(-1) . day(-1), which is based on the average intake of a breastfed infant.
    Journal of Pediatric Gastroenterology and Nutrition 09/2014; 59(3):374-379. DOI:10.1097/MPG.0000000000000434 · 2.87 Impact Factor
  • International Conference of Information Science and Management Engineering; 09/2014
  • Jinping Zhang · Wenjing Shi · Chao Chen
    Pediatrics & Neonatology 08/2014; 56(1). DOI:10.1016/j.pedneo.2014.05.003 · 0.88 Impact Factor
  • Bo Sun · Xuewen Wu · Jun He · Xiaoming Zhu · Chao Chen
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    ABSTRACT: Sparse representation classification method has been increasingly used in the fields of computer vision and pattern analysis, due to its high recognition rate, little dependence on the features, robustness to corruption and occlusion, and etc. However, most of these existing methods aim to find the sparsest representations of the test sample y in an overcomplete dictionary, which do not particularly consider the relevant structure between the atoms in the dictionary. Moreover, sufficient training samples are always required by the sparse representation method for effective recognition. In this paper we formulate the classification as a group-structured sparse representation problem using a sparsity-inducing norm minimization optimization and propose a novel sparse representation-based automatic target recognition (ATR) framework for the practical applications in which the training samples are drawn from the simulation models of real targets. The experimental results show that the proposed approach improves the recognition rate of standard sparse models, and our system can effectively and efficiently recognize targets under real environments, especially, where the good characteristics of the sparse representation based classification method are kept.
    SPIE Defense + Security; 06/2014
  • Jun He · Tian Zuo · Bo Sun · Xuewen Wu · Chao Chen
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    ABSTRACT: This paper is aiming at applying sparse representation based classification (SRC) on face recognition with disguise or illumination variation. Having analyzed the characteristics of general object recognition and the principle of the classifier of SRC method, authors focus on evaluating blocks of a probe sample and propose an optimized SRC method based on position-preserving weighted block and maximum likelihood model. Principle and implementation of the proposed method have been introduced in the article, and experiments on Yale and AR face database have been given too. From experimental results, it can be seen that the proposed optimized SRC method works well than existing methods.
    SPIE Defense + Security; 06/2014
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    ABSTRACT: Objetivo validar de forma prospectiva um nomograma de bilirrubina transcutânea (BTc) para identificar hiperbilirrubinemia grave em neonatos a termo e pré‐termo tardios saudáveis na China. Métodos foi realizado um estudo multicêntrico que incluiu 9174 neonatos a termo e pré‐termo tardios saudáveis em oito unidades da China. Foram realizadas dosagens de BTc utilizando um bilirrubinômetro. Os valores de BTc foram traçados em um nomograma de BTc para identificar a capacidade de predição de hiperbilirrubinemia significativa. Resultados 972 recém‐nascidos (10,6%) desenvolveram hiperbilirrubinemia significativa. O percentil 40 de nosso nomograma pode identificar todos os recém‐nascidos com risco de hiperbilirrubinemia significativa, porém com baixo valor preditivo positivo (VPP) (18,9%). De 453 recém‐nascidos acima do percentil 95, 275 recém‐nascidos desenvolveram posteriormente hiperbilirrubinemia significativa, com VPP elevado (60,7%), porém com baixa sensibilidade (28,3%). O percentil de 75 foi altamente específico (81,9%) e moderadamente sensível (79,8%). A área sob a curva (ASC) de nosso nomograma de BTc foi de 0,875. Conclusões este estudo validou o nomograma de BTc, que pode ser utilizado para prever hiperbilirrubinemia significativa em neonatos a termo e pré‐termo tardios saudáveis na China. Contudo, combinar o nomograma de BTc e fatores de risco clínicos pode melhorar a precisão de predição da hiperbilirrubinemia grave, o que não foi avaliado neste estudo. São necessários estudos adicionais para confirmar essa combinação.
    Jornal de pediatria 05/2014; 90(3). DOI:10.1016/j.jped.2013.08.013 · 0.94 Impact Factor

Publication Stats

318 Citations
142.53 Total Impact Points

Institutions

  • 2007–2015
    • Fudan University
      • Department of Pediatrics
      Shanghai, Shanghai Shi, China
  • 2014
    • The University of Warwick
      • Department of Computer Science
      Coventry, England, United Kingdom
  • 2013
    • Shanghai Children's Hospital
      Shanghai, Shanghai Shi, China