bluuebunny/crossref_metadata_2025_split huggingface dataset:
Curing kinetics of fluorene containing benzoxazine investigated by nonisothermal differential scanning calorimetry
Authors: Lu Yanbing , Li Mingming , Ke Lili , Hu Ding , Xu Weijian 
Published: March 2011

AbstractFluorene containing benzoxazine monomer (B‐pbf) was synthesized from 9, 9‐bis(4‐hydroxyphenyl) fluorene, aniline, and paraformaldehyde via a solution method. The chemical structure of B‐pbf was characterized with FTIR and 1H‐NMR. The curing reaction of B‐pbf was investigated by nonisothermal differential scanning calorimetry (DSC) at different heating rates. The kinetic parameters and the kinetic models of the curing processes were examined utilizing Kissinger, Ozawa, Flynn‐Wall‐Ozawa, and Friedman methods. The average activation energy of the curing reaction was determined to be 95.1 kJ mol−1 and 99.0 kJ mol−1, respectively, according to Kissinger and Ozawa method. The autocatalytic kinetic model was found to be the best description of the investigated curing reaction. The reaction order m and n are 0.95 and 2.03, respectively. In addition, the predicted curves from the kinetic models fit well with the nonisothermal DSC thermograms. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011
Epigenetic programming: From gametes to blastocyst
Authors: Hales Barbara F. , Grenier Lisanne , Lalancette Claudia , Robaire Bernard 
Published: March 2011

AbstractEmbryo development requires a series of cell fate decisions; cell lineages are established early during development and must be “remembered” through multiple cell divisions. It is increasingly evident that epigenetic marks, DNA methylation, histone modifications, and noncoding RNAs, have a critical role in this cell memory during development. During gametogenesis, epigenetic programming results in the production of spermatozoa and oocytes with distinctive chromatin. The goal of this article is to review what is known about the epigenetic marks in mature gametes and how these marks change during early embryo development. An understanding of the role of epigenetic programming during normal development will lay the basis for the elucidation of its role when development goes awry and the consequence is a birth defect. Birth Defects Research (Part A) 2011. © 2011 Wiley‐Liss, Inc.
Expression patterns of placental microRNAs
Authors: Mouillet Jean–Francois , Chu Tianjiao , Sadovsky Yoel 
Published: March 2011

AbstractAmong different types of small RNA molecules, distinct types of microRNAs (miRNAs) are expressed in many cell types, where they modulate RNA stability and translation, thus controlling virtually every aspect of tissue development, proliferation, differentiation, and function. Aberrant miRNA expression has been linked to discrete pathologic processes. As the placenta plays a pivotal role in governing fetal development, it is not surprising that the placenta expresses numerous types of miRNAs. Whereas many of these miRNAs are ubiquitously expressed, certain miRNA species are largely unique to the placenta. Research in the field of placental miRNAs is in its early phase, with most studies centering on cataloging placental miRNA species or examining differences in placental miRNA expression between placentas from normal pregnancies and those from pregnancies complicated by pathologies that are associated with placental dysfunction. Recent research endeavors ventured to assess the function of miRNAs in cultured placental trophoblasts, using in vitro conditions that model relevant pathophysiological processes. The impact of miRNA‐mediated repression on the trophoblast transcriptome, particularly in response to genetic and environmental perturbations, remains largely unknown. Further indepth studies are required to unravel the functional significance of miRNAs in molding placental robustness, which must constantly adapt to altered maternal physiologic status to sustain optimal support to the developing embryo. In this review, we summarize the current information about placental miRNAs expression, and the lingering challenges in this field. Birth Defects Research (Part A) 2011. © 2011 Wiley‐Liss, Inc.
IUGR differentially alters MeCP2 expression and H3K9Me3 of the PPARγ gene in male and female rat lungs during alveolarization
Authors: Joss–Moore Lisa A. , Wang Yan , Ogata Elizabeth M. , Sainz Anthony J. , Yu Xing , Callaway Christopher W. , McKnight Robert A. , Albertine Kurt H. , Lane Robert H. 
Published: March 2011

AbstractIntrauterine growth restriction (IUGR) increases the risk of postnatal lung disease, with males more affected. In rat lungs, IUGR impairs alveolarization in conjunction with altered expression of peroxisome proliferator‐activated receptor gamma (PPARγ). In non‐lung cells, PPARγ transcription is regulated in part by the epigenetic modifying enzyme, and the methyl CpG binding protein 2 (MeCP2). However, it is unknown if IUGR affects MeCP2 expression or its interaction with PPARγ in the rat lung during alveolarization. In this study, we hypothesized that the rat lung would be characterized by the presence of MeCP2 short and long mRNA transcripts, MeCP2 protein isoforms, and the MeCP2 regulatory micro RNA, miR132. We further hypothesized that IUGR would, in a gender‐specific manner, alter the levels of MeCP2 components in association with changes in PPARγ mRNA, MeCP2 occupancy at the PPARγ promoters, and PPARγ histone 3 lysine 9 trimethylation (H3K9Me3). To test these hypotheses, we used a well‐characterized rat model of uteroplacental insufficiency‐induced IUGR. We demonstrated the presence of MeCP2 mRNA, protein, and miR132 in the rat lung throughout alveolarization. We also demonstrated that IUGR alters MeCP2 expression and its interaction with PPARγ in a gender‐divergent manner. We conclude that IUGR induces gender‐specific alterations in the epigenetic milieu in the rat lung. We speculate that in the IUGR rat lung, this altered epigenetic milieu may predispose to gender‐specific alterations in alveolarization. Birth Defects Research (Part A) 2011. © 2011 Wiley‐Liss, Inc.
Symbiosis and development: The hologenome concept
Authors: Rosenberg Eugene , Zilber‐Rosenberg Ilana 
Published: March 2011

AbstractAll animals and plants establish symbiotic relationships with microorganisms; often the combined genetic information of the diverse microbiota exceeds that of the host. How the genetic wealth of the microbiota affects all aspects of the holobiont's (host plus all of its associated microorganisms) fitness (adaptation, survival, development, growth and reproduction) and evolution is reviewed, using selected coral, insect, squid, plant, and human/mouse published experimental results. The data are discussed within the framework of the hologenome theory of evolution, which demonstrates that changes in environmental parameters, for example, diet, can cause rapid changes in the diverse microbiota, which not only can benefit the holobiont in the short term but also can be transmitted to offspring and lead to long lasting cooperations. As acquired characteristics (microbes) are heritable, consideration of the holobiont as a unit of selection in evolution leads to neo‐Lamarckian principles within a Darwinian framework. The potential application of these principles can be seen in the growing fields of prebiotics and probiotics. Birth Defects Research (Part C) 93:56–66, 2011. © 2011 Wiley‐Liss, Inc.
Endocrine disrupting chemicals and the developmental programming of adipogenesis and obesity
Authors: Janesick Amanda , Blumberg Bruce 
Published: March 2011

AbstractObesity and related disorders are a burgeoning public health epidemic, particularly in the U.S. Currently 34% of the U.S. population is clinically obese (BMI > 30) and 68% are overweight (BMI > 25), more than double the worldwide average and 10‐fold higher than Japan and South Korea. Obesity occurs when energy intake exceeds energy expenditure; however, individuals vary widely in their propensity to gain weight and accrue fat mass, even at identical levels of excess caloric input. Clinical, epidemiological, and biological studies show that obesity is largely programmed during early life, including the intrauterine period. The environmental obesogen hypothesis holds that prenatal or early life exposure to certain endocrine disrupting chemicals can predispose exposed individuals to increased fat mass and obesity. Obesogen exposure can alter the epigenome of multipotent stromal stem cells, biasing them toward the adipocyte lineage at the expense of bone. Hence, humans exposed to obesogens during early life might have an altered stem cell compartment, which is preprogrammed toward an adipogenic fate. This results in a higher steady state number of adipocytes and potentially a lifelong struggle to maintain a healthy weight, which can be exacerbated by societal influences that promote poor diet and inadequate exercise. This review focuses on the developmental origins of the adipocyte, the relationship between adipocyte number and obesity, and how obesogenic chemicals may interfere with the highly efficient homeostatic mechanisms regulating adipocyte number and energy balance. Birth Defects Research (Part C) 93:34–50, 2011. © 2011 Wiley‐Liss, Inc.
The role of developmental plasticity and epigenetics in human health
Authors: Gluckman Peter D. , Hanson Mark A. , Low Felicia M. 
Published: March 2011

AbstractConsiderable epidemiological, experimental and clinical data have amassed showing that the risk of developing disease in later life is dependent on early life conditions, mainly operating within the normative range of developmental exposures. This relationship reflects plastic responses made by the developing organism as an evolved strategy to cope with immediate or predicted circumstances, to maximize fitness in the context of the range of environments potentially faced. There is now increasing evidence, both in animals and humans, that such developmental plasticity is mediated in part by epigenetic mechanisms. However, recognition of the importance of developmental plasticity as an important factor in influencing later life health—particularly within the medical and public health communities—is low, and we argue that this indifference cannot be sustained in light of the growing understanding of developmental processes and the rapid rise in the prevalence of obesity and metabolic disease globally. Birth Defects Research (Part C) 93:12–18, 2011. © 2011 Wiley‐Liss, Inc.
Role of epigenetics in developmental biology and transgenerational inheritance
Authors: Skinner Michael K. 
Published: March 2011

AbstractThe molecular mechanisms involved in developmental biology and cellular differentiation have traditionally been considered to be primarily genetic. Environmental factors that influence early life critical windows of development generally do not have the capacity to modify genome sequence, nor promote permanent genetic modifications. Epigenetics provides a molecular mechanism for environment to influence development, program cellular differentiation, and alter the genetic regulation of development. The current review discusses how epigenetics can cooperate with genetics to regulate development and allow for greater plasticity in response to environmental influences. This impacts area such as cellular differentiation, tissue development, environmental induced disease etiology, epigenetic transgenerational inheritance, and the general systems biology of organisms and evolution. Birth Defects Research (Part C) 93:51–55, 2011. © 2011 Wiley‐Liss, Inc.
The effects of alcohol on fetal development
Authors: Jones Kenneth Lyons 
Published: March 2011

AbstractPrenatal exposure to alcohol has profound effects on many aspects of fetal development. Although alterations of somatic growth and specific minor malformations of facial structure are most characteristic, the effects of alcohol on brain development are most significant in that they lead to substantial problems with neurobehavioral development. Since the initial recognition of the fetal alcohol syndrome (FAS), a number of important observations have been made from studies involving both humans and animals. Of particular importance, a number of maternal risk factors have been identified, which may well be of relevance relative to the development of strategies for prevention of the FAS as well as intervention for those who have been affected. These include maternal age >30 years, ethnic group, lower socioeconomic status, having had a previously affected child, maternal under‐nutrition, and genetic background. The purpose of this review is to discuss these issues as well as to set forth a number of questions that have not adequately been addressed relative to alcohol's effect on fetal development. Of particular importance is the critical need to identify the full spectrum of structural defects associated with the prenatal effects of alcohol as well as to establish a neurobehavioral phenotype. Appreciation of both of these issues is necessary to understand the full impact of alcohol on fetal development. Birth Defects Research (Part C) 93:3–11, 2011. © 2011 Wiley‐Liss, Inc.
Epigenetics and the brain: Transcriptome sequencing reveals new depths to genomic imprinting
Authors: Kelsey Gavin 
Published: March 2011

AbstractTranscriptome sequencing has identified more than a thousand potentially imprinted genes in the mouse brain. This comes as a revelation to someone who cut his teeth on the identification of imprinted genes when only a handful was known. Genomic imprinting, an epigenetic mechanism that determines expression of alleles according to sex of transmitting parent, was discovered over 25 years ago in mice but remains an enigmatic phenomenon. Why do these genes disobey the normal Mendelian logic of inheritance, do they function in specific processes, and how is their imprinting conferred? Next generation sequencing technologies are providing an unprecedented opportunity to survey the whole genome for imprinted genes and are beginning to reveal that imprinting may be more pervasive than we had come to believe. Such advances should lay the foundation for a definitive account of imprinting, but may also challenge accepted views on what it means to be imprinted.Editor's suggested further reading in BioEssays RNA as the substrate for epigenome‐environment interactions Abstract
Nucleolar aggresomes as counterparts of cytoplasmic aggresomes in proteotoxic stress
Authors: Latonen Leena 
Published: March 2011

AbstractThe nucleolus may represent a key stress response organelle in the nucleus following proteotoxic stress by serving as a platform for protein aggregates. Aggregation of proteins often results from insufficient protein degradation by the ubiquitin‐proteasome system (UPS), occurring in inclusion diseases, upon treatment by proteasome inhibitors (PIs) or due to various forms of stress. As the nucleolar inclusions resemble cytoplasmic aggresomes in gathering ubiquitin and numerous UPS components and targets, including cancer‐related transcription factors and cell cycle regulators (e.g. p53 and cyclin D) and proteins involved in neurodegenerative diseases (e.g. ataxin‐1, Malin), these organelles are termed herein as nucleolar aggresomes. These nucleolar aggresomes contain polyadenylated RNA, and seem to be linked to defects in nuclear export. Nucleolar aggresomes have been identified in non‐neuronal cells, but prominent similarities with nuclear ubiquitin and/or ribonuclear foci detected in triplet and other repeat disease pathologies are revealed here, creating a common interest between research in cancer and neurodegeneration.
Selectivity and delignification kinetics for oxidative short‐term lime pretreatment of poplar wood, part I: Constant‐pressure
Authors: Sierra‐Ramírez Rocío , Garcia Laura A. , Holtzapple Mark Thomas 
Published: March 2011

AbstractKinetic models applied to oxygen bleaching of paper pulp focus on the degradation of polymers, either lignin or carbohydrates. Traditionally, they separately model different moieties that degrade at three different rates: rapid, medium, and slow. These models were successfully applied to lignin and carbohydrate degradation of poplar wood submitted to oxidative pretreatment with lime at the following conditions: temperature 110–180°C, total pressure 7.9–21.7 bar, and excess lime loading of 0.5 g Ca(OH)2 per gram dry biomass. These conditions were held constant for 1–6 h. The models properly fit experimental data and were used to determine pretreatment selectivity in two fashions: differential and integral. By assessing selectivity, the detrimental effect of pretreatment on carbohydrates at high temperatures and at low lignin content was determined. The models can be used to identify pretreatment conditions that selectively remove lignin while preserving carbohydrates. Lignin removal ≥50% with glucan preservation ≥90% was observed for differential glucan selectivities between ∼10 and ∼30 g lignin degraded per gram glucan degraded. Pretreatment conditions complying with these reference values were preferably observed at 140°C, total pressure ≥14.7 bars, and for pretreatment times between 2 and 6 h depending on the total pressure (the higher the pressure, the less time). They were also observed at 160°C, total pressure of 14.7 and 21.7 bars, and pretreatment time of 2 h. Generally, at 110°C lignin removal is insufficient and at 180°C carbohydrates do not preserve well. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Efficient suspension bioreactor expansion of murine embryonic stem cells on microcarriers in serum‐free medium
Authors: Alfred Roz , Radford Jaret , Fan Jessica , Boon Kathryn , Krawetz Roman , Rancourt Derrick , Kallos Michael S. 
Published: March 2011

AbstractLarge numbers of cells will be required for successful embryonic stem cell (ESC)‐based cellular therapies or drug discovery, thus raising the need to develop scaled‐up bioprocesses for production of ESCs and their derived progeny. Traditionally, ESCs have been propagated in adherent cultures in static flasks on fibroblasts layers in serum‐containing medium. Direct translation of two‐dimensional flatbed cultures to large‐scale production of the quantities of cells required for therapy simply by increasing the number of dishes or flasks is not practical or economical. Here, we describe successful scaled‐up production of ESCs on microcarriers in a stirred culture system in a serum‐free medium. Cells expanded on CultiSpher S, Cytodex 3, and Collagen microcarriers showed superior cell‐fold expansions of 439, 193, and 68, respectively, without excessive agglomeration, compared with 27 in static culture. In addition, the ESCs maintained their pluripotency after long‐term culture (28 days) in serum‐free medium. This is the first time mESCs have been cultured on microcarriers without prior exposure to serum and/or fibroblasts, while also eliminating the excessive agglomeration plaguing earlier studies. These protocols provide an economical, practical, serum‐free means for expanding ESCs in a stirred suspension bioprocess. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Protein hydrolysis by immobilized and stabilized trypsin
Authors: Marques Daniela , Pessela Benavides C. , Betancor Lorena , Monti Rubens , Carrascosa Alfonso V. , Rocha‐Martin Javier , Guisán Jose M. , Fernandez‐Lorente Gloria 
Published: March 2011

AbstractThe preparation of novel immobilized and stabilized derivatives of trypsin is reported here. The new derivatives preserved 80% of the initial catalytic activity toward synthetic substrates [benzoyl‐arginine p‐nitroanilide (BAPNA)] and were 50,000‐fold more thermally stable than the diluted soluble enzyme in the absence of autolysis. Trypsin was immobilized on highly activated glyoxyl‐Sepharose following a two‐step immobilization strategy: (a) first, a multipoint covalent immobilization at pH 8.5 that only involves low pKa amino groups (e.g., those derived from the activation of trypsin from trypsinogen) is performed and (b) next, an additional alkaline incubation at pH 10 is performed to favor an intense, additional multipoint immobilization between the high concentration of proximate aldehyde groups on the support surface and the high pKa amino groups at the enzyme surface region that participated in the first immobilization step. Interestingly, the new, highly stable trypsin derivatives were also much more active in the proteolysis of high molecular weight proteins when compared with a nonstabilized derivative prepared on CNBr‐activated Sepharose. In fact, all the proteins contained a cheese whey extract had been completely proteolyzed after 6 h at pH 9 and 50°C, as determined by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE). Under these experimental conditions, the immobilized biocatalysts preserve more than 90% of their initial activity after 20 days. Analysis of the three‐dimensional (3D) structure of the best immobilized trypsin derivative showed a surface region containing two amino terminal groups and five lysine (Lys) residues that may be responsible for this novel and interesting immobilization and stabilization. Moreover, this region is relatively far from the active site of the enzyme, which could explain the good results obtained for the hydrolysis of high‐molecular weight proteins. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011
Immobilization of active human carboxylesterase 1 in biomimetic silica nanoparticles
Authors: Edwards Jonathan S. , Kumbhar Amar , Roberts Adam , Hemmert Andrew C. , Edwards Carol C. , Potter Philip M. , Redinbo Matthew R. 
Published: March 2011

AbstractThe encapsulation of proteins in biomimetic silica has recently been shown to successfully maintain enzymes in their active state. Organophosphate (OP) compounds are used as pesticides as well as potent chemical warfare nerve agents. Because these toxicants are life threatening, we sought to generate biomimetic silicas capable of responding to OPs. Here, we present the silica encapsulation of human drug metabolism enzyme carboxylesterase 1 (hCE1) in the presence of a range of catalysts. hCE1 was successfully encapsulated into silica particles when lysozyme or the peptide R5 were used as catalysts; in contrast, polyethyleneimine, a catalyst used to encapuslate other enzymes, did not facilitate hCE1 entrapment. hCE1 silica particles in a column chromatography format respond to the presence of the OP pesticides paraoxon and dimethyl‐p‐nitrophenyl phosphate in solution. These results may lead to novel approaches to detect OP pesticides or other weaponized agents that bind hCE1. © 2011 American Institute of Chemical Engineers Biotechnol. Prog., 2011