bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical treatment of mouse Ehrlich tumor with direct electric current
Authors: Cabrales Luis Bergues , Ciria Héctor Camué , Bruzón Rodolfo Pérez , Quevedo Magalys Suárez , Aldana Richard Hinojosa , De Oca Libán Montes , Salas Miriam Fariñas , Peña Odalis de la Guardia 
Published: August 2002

AbstractElectrochemical treatment of cancer utilizes direct electric current (DEC) to produce direct alterations and chemical changes in tumors. However, the DEC treatment is not established and mechanisms are not well understood. In vivo studies were conducted to evaluate the effectiveness of DEC on animal tumor models. Ehrlich tumors were implanted subcutaneously in sixty male BALB/c mice. When the tumor volumes reached 850 mm3, four platinum electrodes were inserted into the tumors. DEC of 4 mA was applied for 21 min to the treated group; the total charge was 5 C. The healthy and sick control groups were subjected to the same conditions but without DEC. Hematological and chemical parameters as well as histopathological and peritumoral findings were studied. After the electrochemical therapy it was observed that both tumor volume decrease and necrosis percentage increase were significant in the treated group. Moreover, 24 h after treatment an acute inflammatory response, as well as sodium ion decrease, and potassium ion and spleen weight increase were observed in this group. It was concluded that both electrochemical reactions (fundamentally those in which reactive oxygen species are involved), and immune system stimulation induced by cytotoxic action of the DEC could constitute the most important antitumor mechanisms. Bioelectromagnetics 22:316–322, 2001. © 2001 Wiley‐Liss, Inc.
Health and safety implications of exposure to electromagnetic fields in the frequency range 300 Hz to 10 MHz
Authors: Litvak E. , Foster K.R. , Repacholi M.H. 
Published: August 2002

AbstractAn international seminar on health effects of exposure to electromagnetic fields (EMF) in the frequency range from 300 Hz to 10 MHz (referred to as the Intermediate Frequency (IF) range) was held in Maastricht, Netherlands, on 7–8 June 1999. The seminar, organized under the International EMF Project, was sponsored jointly by the World Health Organization (WHO), the International Commission on Non‐Ionizing Radiation Protection (ICNIRP), and the Government of the Netherlands. This report does not attempt to summarize all of the material presented at the conference, but focuses on sources of exposure, biophysical and dosimetric considerations pertinent to extrapolating biological data from other frequency ranges to IF and identifies potential health concerns and needs for developing exposure guidelines. This paper is based on presentations at the conference and reports of working groups consisting of the speakers and other experts. It concludes with recommendations for further research aimed at improving health risk assessments in this frequency range. Bioelectromagnetics 23:68–82, 2002. © 2002 Wiley‐Liss, Inc.
Novel adipocyte lines from brown fat: A model system for the study of differentiation, energy metabolism, and insulin action
Authors: Klein Johannes , Fasshauer Mathias , Klein Harald H. , Benito Manuel , Kahn C. Ronald 
Published: August 2002

AbstractAdipose tissue has emerged as an important endocrine regulator of glucose metabolism and energy homeostasis. By virtue of the mitochondrial protein uncoupling protein‐1 (UCP‐1), brown fat additionally plays a unique role in thermoregulation. Interest has focused on this tissue not only as a target for pharmacotherapy of obesity and insulin resistance but also as an endocrine tissue with leptin secretion and high insulin sensitivity. Most studies of adipocytes have been limited either to primary cell culture or to a small number of established cell lines. Recently, we have generated immortalized brown adipocyte cell lines from single newborn mice of different knockout mouse models. These cell lines retain the main characteristics of primary cells including UCP‐1 expression. They display sensitive and diverse metabolic responses to insulin and adrenergic stimulation and have proven to be useful in the characterization of UCP regulation and the role of key insulin signaling elements for insulin action. Here, we outline common approaches to the generation of adipose tissue cell lines. Furthermore, we propose that the novel technique of generating brown adipocyte lines from a single newborn mouse will be instrumental in gaining further insight into the role of a broad range of signaling molecules in adipose tissue biology and in the pathogenesis of insulin resistance. BioEssays 24:382–388, 2002. ©2002 Wiley Periodicals, Inc.
O6‐alkylguanine‐DNA alkyltransferase: Role in carcinogenesis and chemotherapy
Authors: Margison Geoffrey P. , Santibáñez‐Koref Mauro F. 
Published: August 2002

AbstractThe DNA in human cells is continuously undergoing damage as consequences of both endogenous processes and exposure to exogenous agents. The resulting structural changes can be repaired by a number of systems that function to preserve genome integrity. Most pathways are multicomponent, involving incision in the damaged DNA strand and resynthesis using the undamaged strand as a template. In contrast, O6‐alkylguanine‐DNA alkyltransferase is able to act as a single protein that reverses specific types of alkylation damage simply by removing the offending alkyl group, which becomes covalently attached to the protein and inactivates it. The types of damage that ATase repairs are potentially toxic, mutagenic, recombinogenic and clastogenic. They are generated by certain classes of carcinogenic and chemotherapeutic alkylating agents. There is consequently a great deal of interest in this repair system in relation to both carcinogenesis and cancer chemotherapy. BioEssays 24:255–266, 2002. © 2002 Wiley Periodicals, Inc.; DOI 10.1002/bies.10063
Innexins get into the gap
Authors: Phelan Pauline , Starich Todd A. 
Published: August 2002

AbstractConnexins were first identified in the 1970s as the molecular components of vertebrate gap junctions. Since then a large literature has accumulated on the cell and molecular biology of this multi‐gene family culminating recently in the findings that connexin mutations are implicated in a variety of human diseases. Over two decades, the terms “connexin” and “gap junction” had become almost synonymous. In the last few years a second family of gap‐junction genes, the innexins, has emerged. These have been shown to form intercellular channels in genetically tractable invertebrate organisms such as Drosophila melanogaster and Caenorhabditis elegans. The completed genomic sequences for the fly and worm allow identification of the full complement of innexin genes in these two organisms and provide valuable resources for genetic analyses of gap junction function. BioEssays 23:388–396, 2001. © 2001 John Wiley & Sons, Inc.
The role of chemoattraction in cancer metastases
Authors: Moore Malcolm A.S. 
Published: August 2002

AbstractIt has long been unclear as to why particular cancers preferentially metastasize to certain sites. The possibilities usually discussed involve differential survival and proliferation at these sites, or selective trapping with or without preferential homing. A recent report by Muller et al.(1) provides evidence for preferential homing of breast cancer to metastatic sites. The findings indicate that the chemokine receptors CXCR4 and CCR7 are found on breast cancer cells and their ligands are highly expressed at sites associated with breast cancer metastases. This results in chemotaxis, or directed migration of tumor cells from their primary site via the circulation to the preferential sites of metastases. The evidence for this model and its significance are reviewed here. BioEssays 23:674–676, 2001. © 2001 John Wiley & Sons, Inc.
Generalized concentration dependence of globular protein self‐diffusion coefficients in aqueous solutions
Authors: Nesmelova Irina V. , Skirda Vladimir D. , Fedotov Vladimir D. 
Published: August 2002

AbstractThe self‐diffusion coefficients of globular proteins (myoglobin, bovine serum albumin, barstar, lysozyme) in aqueous solutions at different temperatures and pH values are obtained by pulsed‐gradient spin‐echo NMR, and their concentration dependence is analyzed. The generalized concentration dependence of globular protein self‐diffusion coefficients is empirically established, and compared to the concentration dependence of diffusion coefficients of flexible polymers and rigid Brownian particles. © 2002 John Wiley & Sons, Inc. Biopolymers 63: 132–140, 2002
Receptor‐dependent G‐protein activation in lipidic cubic phase
Authors: Navarro Javier , Landau Ehud M. , Fahmy Karim 
Published: August 2002

AbstractThe primary step in cellular signaling by G‐protein‐coupled receptors (GPCRs) is the interaction of the agonist‐activated transmembrane receptor with an intracellular G‐protein. Understanding the underlying molecular mechanisms requires the structural determination of receptor G‐protein complexes that are not yet achieved. The crystal structure of the bovine photoreceptor rhodopsin, a prototypical GPCR, was solved recently and the structures of different states of engineered G‐proteins were reported. Posttranslational hydrophobic modifications of G‐proteins are in most cases removed for crystallization but play functional roles for interactions among G‐protein subunits with receptors, as well as membranes. Bovine rhodopsin is reconstituted into lipidic cubic phases to assess their potential for crystallization of receptor G‐protein complexes under conditions that may preserve the structural and functional roles of hydrophobic protein modifications. Three‐dimensional bilayers of a bicontinuous lipidic cubic phase are successfully employed for crystallization of membrane and soluble proteins. UV–visible absorption and attenuated total reflection Fourier transform IR difference spectroscopy reveal that light activation of cubic phase reconstituted rhodopsin results in the generation of a metarhodopsin II‐like state. Via diffusion along aqueous channels, transducin couples efficiently to this photoproduct as evidenced by the nucleotide‐dependent increase of transducin fluorescence. Thus, rhodopsin transducin interactions do not crucially depend on the presence of sn1 and sn2 acyl chains, phospholipid head groups, or membrane planarity. Because lipidic cubic phases preserve the essential functional and structural properties of native rhodopsin and transducin, they appear suitable for the detergent‐free crystallization of receptor G‐protein complexes carrying a normal pattern of hydrophobic modifications. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 167–177, 2002
Influence of Ca2+ cations on low pH‐induced DNA structural transitions
Authors: Muntean C. M. , Puppels G. J. , Greve J. , Segers‐Nolten G. M. J. 
Published: August 2002

AbstractA confocal Raman microspectrometer was used to investigate the influence of Ca2+ cations on low pH‐induced DNA structural changes. The effects of Ca2+ cations on the protonation mechanism of opening AT and changing the protonation of GC base pairs in DNA are discussed. Based on the observation that the midpoint of the transition of Watson–Crick GC base pairs to protonated GC base pairs lies at around pH 3 (analyzing the 681 cm−1 line), measurements were carried out on calf thymus DNA at neutral pH and pH 3 in the presence of low and high concentrations of Ca2+ cations. Raman spectra show that low concentrations of Ca2+ cations partially protect DNA against protonation of cytosine (characteristic line at 1262 cm−1) and do not protect adenine (characteristic line at 1304 cm−1) and the N(7) of guanine (line at 1488 cm−1) against binding of H+. High Ca2+ concentrations can prevent protonation of cytosine and protonation of adenine (little disruption of AT pairs). Analyzing the line at 1488 cm−1, which obtains most of its intensity from a guanine vibration, high salt was also found to protect the N(7) of guanine against protonation. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 282–284, 2002
A novel reactor for making uniform capsules
Authors: Anilkumar A. V. , Lacik I. , Wang T. G. 
Published: August 2002

AbstractA novel chemical reactor was designed and developed for the continuous high‐rate production of uniform capsules. This reactor helps to control precisely the reaction time between the reacting liquids (anion drops and the cation bath, or vice versa), thereby leading to the formation of uniform capsules with walls of identical thickness. In addition, mild tumbling of the capsules during transit through the reactor ensures that every capsule wall is uniformly thick all around. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 581–589, 2001.
Effect of copy number and mRNA processing and stabilization on transcript and protein levels from an engineered dual‐gene operon
Authors: Smolke Christina D. , Keasling Jay D. 
Published: August 2002

AbstractTo study the effect of mRNA stability and DNA copy number on protein production from a dual‐gene operon, a synthetic operon containing the reporter genes gfp and lacZ under the control of the araBAD promoter was placed in pMB1‐based (approximately 100 copies/cell) and F plasmid‐based (approximately 1 copy/cell) vectors. DNA cassettes encoding secondary structures were placed at the 5' and 3' ends of the genes and a putative RNase E site was placed between the two genes. Although the copy number of the pMB1‐based vectors was approximately 100‐fold greater than the copy number of the F plasmid‐based vectors, transcript and protein levels from the pMB1‐based vector were not 100‐fold greater than from the F plasmid‐based vectors. In identical plasmid backbones, different combinations of mRNA control elements were used to alter steady‐state levels of transcripts. Control elements that amplified the stability of one coding region relative to another amplified the ratio of protein produced from those transcripts. The effects of mRNA stability control elements were greater at low inducer concentrations, where mRNA levels limit protein production, than at high inducer concentrations. Although we can alter mRNA and protein levels through copy number, induction level, and mRNA stability control elements, some aspect of gene expression remains dependent on inherent characteristics of the coding region. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 78: 412–424, 2002.
Determination of the maximum specific uptake capacities for glucose and oxygen in glucose‐limited fed‐batch cultivations of Escherichia coli
Authors: Lin H. Y. , Mathiszik B. , Xu B. , Enfors S.‐O. , Neubauer P. 
Published: August 2002

AbstractA simple pulse‐based method for the determination of the maximum uptake capacities for glucose and oxygen in glucose limited cultivations of E. coli is presented. The method does not depend on the time‐consuming analysis of glucose or acetate, and therefore can be used to control the feed rate in glucose limited cultivations, such as fed‐batch processes. The application of this method in fed‐batch processes of E. coli showed that the uptake capacity for neither glucose nor oxygen is a constant parameter, as often is assumed in fed‐batch models. The glucose uptake capacity decreased significantly when the specific growth rate decreased below 0.15 h−1 and fell to about 0.6 mmol g−1 h−1 (mmol per g cell dry weight and hour) at the end of fed‐batch fermentations, where μ was approximately 0.02 h−1. The oxygen uptake capacity started to decrease somewhat earlier when μ declined below 0.25 h−1 and was 5 mmol g−1 h−1 at the end of the fermentations. The behavior of both uptake systems is integrated in a dynamic model which allows a better fitting of experimental values for glucose in fed‐batch processes in comparison to generally used unstructured kinetic models. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 347–357, 2001.
Efficient preparation of (R)‐α‐monobenzoyl glycerol by lipase catalyzed asymmetric esterification: Optimization and operation in packed bed reactor
Authors: Xu Jian‐He , Kato Yasuo , Asano Yasuhisa 
Published: August 2002

AbstractOptically active (R)‐α‐monobenzoyl glycerol (MBG) was synthesized by Candida antarctica lipase B (CHIRAZYME® L‐2) catalyzed asymmetric esterification of glycerol with benzoic anhydride in organic solvents. Various conditions, such as the type and composition of the organic solvent, water content of the system, reaction temperature, and concentrations of the substrates were systematically examined and optimized in screw‐capped test tubes with respect to both the reaction rate and the enzyme selectivity. 1,4‐Dioxane was found to be the best solvent and no additional water was needed for the system. The optimum temperature was around 30°C, while the most suitable substrate concentrations were 100 mM each for glycerol and benzoic anhydride, respectively. However, when excessive anhydride (e.g., 200 mM) was used, the produced MBG could be further transformed into 1,3‐dibenzoyl glycerol (DBG) by the same enzyme with a priority to (S)‐MBG, resulting in a significant improvement of the product optical purity from ca. 50–70% e.e. Under optimal conditions (100 mM glycerol, 100–200 mM benzoic anhydride, dioxane, 25–30°C), the enzymatic synthesis of (R)‐MBG was successfully operated in a packed‐bed reactor for about 1 week, with an average productivity of 0.79 g MBG/day/g biocatalyst in the case of continuous operation and 0.94 g MBG/day/g biocatalyst in the case of semicontinuous operation. After refinement and preferential crystallization of the crude product, (R)‐MBG could be obtained in an almost optically pure form (>98% e.e.). © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 73: 493–499, 2001.
Photosynthetic productivity of conical helical tubular photobioreactors incorporating Chlorella sp. under various culture medium flow conditions
Authors: Morita Masahiko , Watanabe Yoshitomo , Okawa Tomio , Saiki Hiroshi 
Published: August 2002

AbstractThe characteristics of the flow of culture medium significantly affects the photosynthetic productivity of bioreactors incorporating microalgae. Therefore, in order to optimize the performance of a conical helical tubular photobioreactor (CHTP) designed to be useful in practical applications, we characterized the flow pattern of the culture medium through the reactor. The effects of medium flow conditions on the photosynthetic productivity of Chlorella sp. were investigated using several different CHTP units with 0.50‐m2 installation areas which were designed to vary the direction and rate of flow driven by airlift. In addition, the performance of two‐ and four‐unit systems constructed by combining individual CHTP units was evaluated. We found that when medium flowed from the bottom to the top of the photostage, it exhibited smoother flow of culture medium than when flowing from top to bottom, which led to higher photosynthetic productivity by the former. Consistent with theoretical calculations, varying the lengths of vertical flow passages caused flow rates to vary, and higher flow rates meant smoother circulation of medium and better photosynthetic performance. Flow of medium through a four‐unit CHTP system was similar to that in single units, enabling a photosynthetic productivity of 31.0 g‐dry biomass per m2‐installation area per day to be achieved, which corresponded to a photosynthetic efficiency of 7.50% (photosynthetically active radiation (PAR; 400–700 nm)). This high photosynthetic performance was possible because smoother medium flow attained in single units was also attained in the four‐unit system. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 74: 136–144, 2001.
Expression of the transcription factor GADD153 is an indicator of apoptosis for recombinant chinese hamster ovary (CHO) cells
Authors: Murphy Tracy C. , Woods Nigel R. , Dickson Alan J. 
Published: August 2002

AbstractLoss of cell viability, through engagement of apoptotic cell death, represents a limitation to maintenance of high levels of productivity of recombinant animal cells in culture. The ability to monitor the status of recombinant cells, and to define indicators of their “well‐being,” would present a valuable approach to permit a rational intervention at appropriate times during culture. Growth arrest and DNA damage gene 153 (GADD153) is a member of the CCAAT/enhancer‐binding protein (C/EBP) family of transcription factors and has been associated with apoptosis. We have examined the expression of GADD153 in conditions associated with apoptosis of recombinant CHO cells in batch culture. GADD153 expression is very low in CHO cells growing in the exponential phase of batch culture but is activated as cells enter the decline phase. Depletion of nutrients (glucose or glutamine) causes activation of GADD153 expression as does the imposition of endoplasmic reticulum stress. In all cases, there is a good relationship between the extent of apoptosis that occurs in response to each stress and the degree of GADD153 expression. In addition, nutrient refeeding or reversal of stress produces a concomitant decrease in expression of GADD153 and the susceptibility to apoptosis. Thus, GADD153 appears to offer a valid indicator of apoptosis and illustrates the potential for definition of monitors of cellular status related to the likelihood of apoptosis of cell populations. © 2001 John Wiley & Sons, Inc. Biotechnol Bioeng 75: 621–629, 2001.
Preadolescent adjudicative competence: methodological considerations and recommendations for practice standards
Authors: Oberlander Lois B. , Goldstein Naomi E. , Ho Caleb N. 
Published: August 2002

AbstractThis article examines developmental and legal issues directed toward a downward age extension of forensic evaluation practice standards for preadolescent defendants whose competence is questioned. Existing research and practice standards were developed for cases involving adolescents and adults, but they lack sufficient application to evaluations of young children because of the ways in which legal parameters affect young children. We review practice implications of the legal role of “immaturity” for adjudicative competence, alterations of Dusky in some juvenile courts, and the role of parens patriae in competence hearings held in juvenile court. We examine competence abilities in a developmental framework. Examining practice standards is timely because adjudicative competence in preadolescent defendants has taken on recent significance. The last decade saw changes in the stringency of delinquency statutes, increased emphasis on adversarial approaches to juvenile proceedings, and a de‐emphasis on rehabilitation and parens patriae protections. Statutory changes and increased referrals have heightened inquiry into the meaning of preadolescent adjudicative competence. Copyright © 2001 John Wiley & Sons, Ltd.
Murderers' and sexual offenders' experiences of police interviews and their inclination to admit or deny crimes
Authors: Holmberg Ulf , Christianson Sven‐Åke 
Published: August 2002

AbstractThis research concerns murderers' and sexual offenders' experiences of Swedish police interviews and their attitudes towards allegations of these serious crimes. The explorative study is based on a questionnaire answered by 83 men convicted of murder or sexual offences. Results show that when police officers interview murderers and sexual offenders, the individuals perceive attitudes that are characterized by either dominance or humanity. Logistic regression shows that police interviews marked by dominance are mainly associated with a higher proportion of denials, whereas an approach marked by humanity is associated with admissions. When suspects feel that they are respected and acknowledged, they probably gain more confidence and mental space, allowing them to admit criminal behaviour. Copyright © 2002 John Wiley & Sons, Ltd.