bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression profiling of transforming growth factor β superfamily genes in developing orofacial tissue
Authors: Mukhopadhyay Partha , Greene Robert M. , Pisano M. Michele 
Published: August 2006

AbstractBACKGROUND:Numerous signaling molecules have been shown to participate in the dynamic process of orofacial development. Among these signal mediators, members of the transforming growth factor β (TGFβ) superfamily have been shown to play critical roles. Developing orofacial tissue expresses TGFβ and bone morphogenetic protein (BMP) mRNAs, their protein isoforms and TGFβ‐ and BMP‐specific receptors. All these molecules display unique temporospatial patterns of expression in embryonic orofacial tissue, suggesting functional roles in orofacial development. For example, the TGFβs and BMPs regulate maxillary mesenchymal cell proliferation and extracellular matrix synthesis. This is particularly noteworthy in that perturbation of either process results in orofacial clefting. Although the cellular and phenotypic effects of the TGFβ superfamily of growth factors on embryonic orofacial tissue have been extensively studied, the specific genes that function as effectors of these cytokines in orofacial development have not been well defined.METHODS:In the present study, oligonucleotide‐based microarray technology was utilized to provide a comprehensive analysis of the expression of the panoply of genes related to the TGFβ superfamily, as well as those encoding diverse groups of proteins functionally associated with this superfamily, during orofacial ontogenesis.RESULTS:Of the ˜7000 genes whose expression was detected in the developing orofacial region, 249 have been identified that encode proteins related to the TGFβ superfamily. Expression of some (27) of these genes was temporally regulated. In addition, several candidate genes, whose precise role in orofacial development is still unknown, were also identified. Examples of genes constituting this cluster include: TGFβ1‐induced antiapoptotic factor‐1 and ‐2, TGFβ‐induced factor 2, TGFβ1 induced transcript‐1 and ‐4, TGFβ‐inducible early growth response 1, follistatin‐like 1, follistatin‐like 3, transmembrane protein with EGF‐like and two follistatin‐like domains (Tmeff)‐1 and ‐2, nodal modulator 1, various isoforms of signal transducers and activators of transcription (Stat), notch, and growth and differentiation factors.CONCLUSIONS:Elucidation of the precise physiological roles of these proteins in orofacial ontogenesis should provide unique insights into the intricacies of the TGFβ superfamily signal transduction pathways utilized during orofacial development. Birth Defects Research (Part A) 76:528–543, 2006. © 2006 Wiley‐Liss, Inc.
Review: Hyperthermia and fever during pregnancy
Authors: Edwards Marshall J. 
Published: August 2006

AbstractAn episode of hyperthermia is not uncommon during pregnancy. The consequences depend on the extent of temperature elevation, its duration, and the stage of development when it occurs. Mild exposures during the preimplantation period and more severe exposures during embryonic and fetal development often result in prenatal death and abortion. Hyperthermia also causes a wide range of structural and functional defects. The central nervous system (CNS) is most at risk probably because it cannot compensate for the loss of prospective neurons by additional divisions by the surviving neuroblasts and it remains at risk at stages throughout pre‐ and postnatal life. In experimental animals the most common defects are of the neural tube, microphthalmia, cataract, and micrencephaly, with associated functional and behavioral problems. Defects of craniofacial development including clefts, the axial and appendicular skeleton, the body wall, teeth, and heart are also commonly found. Nearly all these defects have been found in human epidemiological studies following maternal fever or hyperthermia during pregnancy. Suggested future human studies include problems of CNS function after exposure to influenza and fever, including mental retardation, schizophrenia, autism, and cerebral palsy. Birth Defects Research (Part A) 76:507–516, 2006. © 2006 Wiley‐Liss, Inc.
Combined supplementation of folic acid and vitamin E diminishes diabetes‐induced embryotoxicity in rats
Authors: Gäreskog Mattias , Eriksson Ulf J. , Wentzel Parri 
Published: August 2006

AbstractBACKGROUND: Oxidative stress and enhanced apoptosis may be involved in the induction of embryonic dysmorphogenesis in diabetic pregnancy. Administration of folic acid or vitamin E diminishes embryonic dysmorphogenesis. We aimed to evaluate the effect of combined treatment with folic acid and vitamin E on the disturbed development in embryos of diabetic rats. METHODS: Pregnant nondiabetic and diabetic rats were treated with daily injections of 15 mg/kg folic acid or with 5% vitamin E in the diet. A third group received combined treatment. Day 10 and day 11 embryos were evaluated for development and apoptotic profile. RESULTS: We found increased malformations, resorptions, and profound growth retardation in embryos of diabetic rats compared to control embryos. Vitamin E or folic acid alone, or the 2 compounds combined, normalized embryonic demise. Maternal diabetes caused decreased nuclear factor–κB (NF‐κB) activity and B‐cell lymphoma 2 (Bcl‐2) protein level, and increased Bcl‐2–associated x proteins (Bax) in embryos. Supplementation of vitamin E alone normalized the Bax protein level in a diabetic environment. Administration of folic acid to diabetic rats increased NF‐κB activity and Bcl‐2 protein level. Combined treatment normalized Bcl‐2 and Bax protein level in a diabetic environment. CONCLUSIONS: Combined supplementation of folic acid and vitamin E to pregnant diabetic rats diminished diabetes‐induced malformations and resorptions, concomitant with normalization of apoptotic protein levels. No treatment completely abolished the embryonic demise; therefore, other mechanisms than oxidative stress and apoptosis are likely to be involved in diabetic embryopathy. Birth Defects Research (Part A) 76:483–490, 2006. © 2006 Wiley‐Liss, Inc.
Zebrafish as a model for developmental neurotoxicity testing
Authors: Ton Christopher , Lin Yingxin , Willett Catherine 
Published: August 2006

AbstractBACKGROUND:To establish zebrafish as a developmental toxicity model, we used 7 well‐characterized compounds to examine several parameters of neurotoxicity during development.METHODS:Embryos were exposed by semistatic immersion from 6 hrs postfertilization (hpf). Teratogenicity was assessed using a modified method previously developed by Phylonix. Dying cells in the brain were assessed by acridine orange staining (these cells are likely to be apoptotic). Motor neurons were assessed by antiacetylated tubulin staining and catecholaminergic neurons were visualized by antityrosine hydroxylase staining.RESULTS:Atrazine, dichlorodiphenyltrichloroethane (DDT), and 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin (TCDD) were primarily teratogenic and not specifically neurotoxic. 2,4‐dichlorophenoxyacetic acid (2,4‐D), dieldrin, and nonylphenol showed specific neurotoxicity; dieldrin and nonylphenol were specifically toxic to catecholaminergic neurons. Malathion, although not teratogenic, showed some nonspecific toxicity.CONCLUSIONS:Teratogenicity measured in 96‐hpf zebrafish is predictive of mammalian teratogenicity and is useful in determining whether a compound causes specific neurotoxicity or general developmental toxicity. Induction of apoptosis or necrosis is an indicator of neurotoxicity. An effect on motor neurons in the caudal third of the embryo correlates with expected defects in motility. Overall, our results showed a strong correlation with mammalian data and suggest that zebrafish is a predictive animal model for neurotoxicity screening. Birth Defects Research (Part A) 76:553–567, 2006. Published 2006 Wiley‐Liss, Inc.
Integrity of the methylation cycle is essential for mammalian neural tube closure
Authors: Dunlevy Louisa P.E. , Burren Katie A. , Mills Kevin , Chitty Lyn S. , Copp Andrew J. , Greene Nicholas D.E. 
Published: August 2006

AbstractBACKGROUND:Closure of the cranial neural tube during embryogenesis is a crucial process in development of the brain. Failure of this event results in the severe neural tube defect (NTD) exencephaly, the developmental forerunner of anencephaly.METHODS:The requirement for methylation cycle function in cranial neural tube closure was tested by treatment of cultured mouse embryos with cycloleucine or ethionine, inhibitors of methionine adenosyl transferase. Embryonic phenotypes were investigated by histological analysis, and immunostaining was performed for markers of proliferation and apoptosis. Methylation cycle intermediates s‐adenosylmethionine and s‐adenosylhomocysteine were also quantitated by tandem mass spectrometry.RESULTS:Ethionine and cycloleucine treatments significantly reduced the ratio of abundance of s‐adenosylmethionine to s‐adenosylhomocysteine and are, therefore, predicted to suppress the methylation cycle. Exposure to these inhibitors during the period of cranial neurulation caused a high incidence of exencephaly, in the absence of generalized toxicity, growth retardation, or developmental delay. Reduced neuroepithelial thickness and reduced density of cranial mesenchyme were detected in ethionine‐treated but not cycloleucine‐treated embryos that developed exencephaly. Reduced mesenchymal density is a potential cause of ethionine‐induced exencephaly, although we could not detect a causative alteration in proliferation or apoptosis prior to failure of neural tube closure.CONCLUSIONS:Adequate functioning of the methylation cycle is essential for cranial neural tube closure in the mouse, suggesting that suppression of the methylation cycle could also increase the risk of human NTDs. We hypothesize that inhibition of the methylation cycle causes NTDs due to disruption of crucial reactions involving methylation of DNA, proteins or other biomolecules. Birth Defects Research (Part A) 76:544–552, 2006. © 2006 Wiley‐Liss, Inc.
Acridin‐9‐yl exchange: A proposal for the action of some 9‐aminoacridine drugs
Authors: Šebestík Jaroslav , Šafařík Martin , Stibor Ivan , Hlaváček Jan 
Published: August 2006

AbstractThe finding that several derivatives of 9‐aminoacridine were deacridinylated in the presence of primary aliphatic amines during the solid phase synthesis of acridine–peptide conjugates prompted us to investigate the acridin‐9‐yl moiety transfer from a relatively low‐molecular acridine source to a high‐molecular carrier. The hydrophobic polymer was used as a model of hydrophobic core of biologically active proteins. While the α‐amino group in the peptide was found to play the role of weak acridine acceptor, the ϵ‐amino group of lysine appeared to serve as a moderate acceptor of acridine moiety. The covalent modification of the lysine residues side chain in the hydrophobic core of prion protein aggregates could thus explain the discrepancy between the ability of the acridine drug quinacrine to reduce efficiently the incidence of prion protein in cell culture and its weak prion binding affinity. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 605–614, 2006This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Bioprocess monitoring and computer control: Key roots of the current PAT initiative
Authors: Junker B.H. , Wang H.Y. 
Published: August 2006

AbstractThis review article has been written for the journal, Biotechnology and Bioengineering, to commemorate the 70th birthday of Daniel I.C. Wang, who served as doctoral thesis advisor to each of the co‐authors, but a decade apart. Key roots of the current PAT initiative in bioprocess monitoring and control are described, focusing on the impact of Danny Wang's research as a professor at MIT. The history of computer control and monitoring in biochemical processing has been used to identify the areas that have already benefited and those that are most likely to benefit in the future from PAT applications. Past applications have included the use of indirect estimation methods for cell density, expansion of on‐line/at‐line and on‐line/in situ measurement techniques, and development of models and expert systems for control and optimization. Future applications are likely to encompass additional novel measurement technologies, measurements for multi‐scale and disposable bioreactors, real time batch release, and more efficient data utilization to achieve process validation and continuous improvement goals. Dan Wang's substantial contributions in this arena have been one key factor in steering the PAT initiative towards realistic and attainable industrial applications. © 2006 Wiley Periodicals, Inc.
From microcarriers to hydrodynamics: Introducing engineering science into animal cell culture
Authors: Croughan Matthew S. , Hu Wei‐Shou 
Published: August 2006

AbstractProfessor Daniel I.C. Wang has conducted research in animal cell culture for approximately 40 years. Over that long time period and still to this day, he successfully addresses a multitude of engineering challenges, taking a unique, creative, systems‐driven but still fundamental approach. As mammalian cell culture has become the predominant method of manufacturing therapeutic proteins, the impact of his leadership, not only in research but also student recruitment and education, has played a key role in the success of the bio/pharmaceutical industry. © 2006 Wiley Periodicals, Inc.
Daniel I.C. Wang: A tribute to an inspirational leader and colleague
Authors: Hatton T. Alan 
Published: August 2006

AbstractDaniel I.C. Wang has been an influential leader of the biotechnology industry over the past four decades through his inspirational research activities, the legions of students and other researchers that have studied under him, his development of many research and educational initiatives, both nationally and internationally, and the advice he has given worldwide to companies, research institutions, universities, and governments. He has played an important role in the mentoring and nurturing of junior faculty members, and has been a supportive collaborator in research and teaching. This two‐part article provides a brief overview of Danny Wang's many contributions to furthering the global development of biotechnology, with particular emphasis on his recent activities in Asia, and concludes with an account of his research collaborations with the author over the past two decades. © 2006 Wiley Periodicals, Inc.
Computer‐aided material balancing for prediction of fermentation parameters
Authors: Cooney Charles L. , Wang Henry Y. , Wang Daniel I.C. 
Published: August 2006

AbstractDespite the importance of biomass as a parameter in fermentation processes, there are no commercially available sensors suitable for its measurement. An indirect approach for the assessment of biomass concentration can be based on material balances and on the direct monitoring of fermentation parameters for which there are established sensors (e.g., gaseous oxygen and carbon dioxide). As a consequence, this method requires no assumption of cellular yield coefficients or rate constants. This approach is also readily adaptable to general use since it requires only some knowledge of the compositions of the substrate, cells, and noncellular products. © 2006 Wiley Periodicals, Inc.
Computer control of the penicillin fermentation using the filtration probe in conjunction with a structured process model
Authors: Nestaas Eirik , Wang Daniel I. C. 
Published: August 2006

AbstractA structured model for the penicillin fermentation is presented. This model includes three different cell types: 1) hyphae tips, 2) penicillin‐producing cells, and 3) degenerated, matabolically inactive cells. Cell degeneration has been described previously as a gradual loss of cytoplasmic material by endogenous metabolism. The rate at which such loss of cytoplasm (and activity) proceeds can be expressed as a linear function of the specific growth rate. At growth rates above some minimum value (0.0115 h−1) cell degeneration can be prevented. This model served as the control basis during open‐loop as well as closed‐loop computer control of the fermentation. Closed‐loop control was achieved through feedback information of biomass concentration using a filtration probe and was required when complex nutrients contributed significantly to the overall biomass production. © 2006 Wiley Periodicals, Inc.
A mechanistic analysis of the inoculum requirement for the cultivation of mammalian cells on microcarriers
Authors: Hu W.S. , Meier J. , Wang D.I.C. 
Published: August 2006

AbstractFor the cultivation of mammalian cells on microcarriers a minimum inoculum concentration is required to initiate cell attachment and subsequent cell growth. A critical cell number model has been proposed to elucidate the mechanism of the inoculum requirement. In this model it was hypothesized that after inoculation a critical number of cells per microcarrier is required for normal growth to occur; failure to acquire enough cells will impede cell growth. This critical cell number model was expressed mathematically and used to simulate cell distribution and growth on microcarriers under different cultivation conditions. By comparing the simulated growth kinetics with the experimental results, the actual critical cell number per microcarrier was identified. The critical number could be reduced by employing an improved medium for the cultivation. © 2006 Wiley Periodicals, Inc.
Hydrodynamic effects on animal cells grown in microcarrier cultures
Authors: Croughan Matthew Shane , Hamel Jean‐Francois , Wang Daniel I.C. 
Published: August 2006

AbstractHydrodynamic phenomena in microcarrier cultures are investigated with regard to the development of improved reactor designs for large‐scale operations. New concepts and theoretical models that describe new data as well as previously published data are presented. © 2006 Wiley Periodicals, Inc.
Protein refolding in reversed micelles
Authors: Hagen Anna J. , Hatton T. Alan , Wang Daniel I.C. 
Published: August 2006

AbstractA novel process has been developed which uses reversed micelles to isolate denatured protein molecules from each other and allows them to refold individually. These reversed micelles are aqueous phase droplets stabilized by the surfactant AOT and suspended in iso‐octane. By adjusting conditions such that only one protein molecule is present per reversed micelle, it was possible to achieve independent folding without encountering the problem of aggregation due to interactions with neighboring molecules. The feasibility of this process was demonstrated using bovine pancreatic ribonuclease A as a model system. It was shown that denatured and reduced ribonuclease can be transferred from a buffered solution containing guanidine hydrochloride into reversed micelles to a greater extent than native enzyme under the same conditions. The denaturant concentration can then be significantly reduced in the reversed micellar phase, while retaining most of the protein, by means of extractive contacting stages with a denaturant‐free aqueous solution. Denatured and reduced ribonuclease will subsequently recover full activity inside reversed micelles within 24 h upon addition of a mixture of reduced and oxidized glutathione to reoxidize disulfide bonds. Extraction of this refolded enzyme from reversed micelles back into aqueous solution can be accomplished by contacting the reversed micelle phase with a high ionic strength (1.0 M KCI) aqueous solution containing ethyl acetate. © 2006 Wiley Periodicals, Inc.
Fed‐batch cultivation of animal cells using different medium design concepts and feeding strategies
Authors: Xie Liangzhi , Wang Daniel I.C. 
Published: August 2006

AbstractIn animal cell cultivation, cell density and product concentration are often low due to the accumulation of toxic end‐products such as ammonia and lactate and/or the depletion of essential nutrients. A hybridoma cell line (CRL‐1606) was cultivated in T‐flasks using a newly devised medium feeding strategy. The goals were to decrease ammonia and lactate formation by the design of an initial medium which would provide a starting environment to achieve optimal cell growth. This was followed by using a stoichiometric equation governing animal cell growth and then designing a supplemental medium for feeding strategy used to control the nutritional environment. The relationship between the stoichiometric demands for glutamine and nonessential amino acids was also studied. Through stoichiometric feeding, nutrient concentrations were controlled reasonably well. Consequently, the specific production rate of lactate was decreased by fourfold compared with conventional fed‐batch culture and by 26‐fold compared with conventional batch culture. The specific production rate of ammonia was decreased by tenfold compared with conventional fed‐batch culture and by 50‐fold compared with conventional batch culture. Most importantly, total cell density and monoclonal antibody concentration were increased by five‐ and tenfold respectively, compared with conventional batch culture. © 2006 Wiley Periodicals, Inc.
A Facile Route to the Non‐IPR Fullerene Sc3N@C68: Synthesis, Spectroscopic Characterization, and Density Functional Theory Computations (IPR=Isolated Pentagon Rule)
Authors: Yang Shangfeng , Kalbac Martin , Popov Alexey , Dunsch Lothar 
Published: August 2006

AbstractOwing to the unique feature of the non‐IPR D3 (isomer 6140) C68 cage (IPR=isolated pentagon rule), Sc3N@C68 has been attracting great interest in the fullerene community. Herein we report the first high‐yield synthesis of Sc3N@C68 by the “reactive gas atmosphere” method and its facile isolation by single‐step HPLC to a high purity (≥99 %). Thus, Sc3N@C68 is isolated in sufficient quantities for its further spectroscopic characterization, while the high purity of the sample ensures the reliability of the spectroscopic data obtained. In particular, the electronic and vibrational structures of Sc3N@C68 were studied in detail experimentally and by theoretical computations. The assignment of the observed absorption bands to particular electronic transitions is given in detail on the basis of time‐dependent DFT computations. Vibrational spectroscopy of Sc3N@C68 reveals good agreement between the measured spectra and the theoretically calculated spectra. A detailed assignment of the vibrational modes, including the Sc3N cluster modes, cage modes, and vibrations of the adjacent pentagons are discussed. This study reveals that the effect of Sc3N encapsulation in the cage is much more complicated than just a formal transfer of six electrons. Consequently the electronic and vibrational spectra of the carbon cage in Sc3N@C68 cannot be adequately understood on the basis of a C686− cage alone.
Silver Coordination Complexes as Room‐Temperature Multifunctional Materials
Authors: Pucci Daniela , Barberio Giovanna , Bellusci Anna , Crispini Alessandra , Donnio Bertrand , Giorgini Loris , Ghedini Mauro , La Deda Massimo , Szerb Elisabeta Ildyko 
Published: August 2006

AbstractA series of bischelate ionic silver complexes [Ag(L*)2][X] was prepared by complexation of a newly synthesized 2,2′‐bipyridine containing chiral alkoxy chains in the 4,4′ positions. The appropriate choice of the construction motifs allows the preparation of new materials in which several functionalities can be introduced. Indeed, when the anion X−is a triflate or a dodecylsulfate group, the right combination of intermolecular interactions promotes the production of liquid crystalline mesophases. Therefore, the presence of coordinating anions, which drives the supramolecular assembly, is essential to generate, at the same time, room‐temperature columnar hexagonal mesomorphism, the columnar helical supramolecular structure, and excimeric emission.