bluuebunny/crossref_metadata_2025_split huggingface dataset:
Understanding Rho/Rac biology in T‐cells using animal models
Authors: Bustelo Xosé R. 
Published: October 2002

AbstractExperiments with cell lines have unveiled the implication of the Rho/Rac family of GTPases in cytoskeletal organization, mitogenesis, and cell migration. However, there have not been adequate animal models to investigate the role of these proteins in more physiological settings. This scenario has changed recently in the case of the T‐cell lineage after the generation of animal models for Rho/Rac family members, their regulators, and effectors. These studies have revealed the implication of these GTPases on multiple regulatory layers of T‐cells, including the coordination of cytoskeletal change, activation of kinase cascades, stimulation of calcium fluxes, and the induction of gene expression. These pathways affect the transition of different T‐cell maturation stages, the positive/negative selection of thymocytes, T‐cell responses to antigens, and the homeostasis of peripheral T‐lymphocytes. Moreover, these animals have revealed interesting cross‐talks between Rho/Rac pathways and other signal transduction routes that participate in lymphocyte responses. BioEssays 24:602–612, 2002. © 2002 Wiley Periodicals, Inc.
Identification of the mouse Loop‐tail gene: a model for human craniorachischisis?
Authors: Kapron Carolyn 
Published: October 2002

AbstractNeural tube defects are one of the commonest human birth defects, with more than 0.5% of some populations affected. Mouse models are being used in an attempt to identify genes that could be involved in these malformations. Only two mouse mutations are known to lead to craniorachischisis, failure of closure of almost the entire neural tube. Two recent papers report that the gene for one of these, Loop‐tail, has now been identified and sequenced.1, 2 It has been given the designation Ltap/Lpp1 and appears to function in floor plate formation. It will be of great interest to investigate the role of this gene in human neural tube defects. BioEssays 24:580–583, 2002. © 2002 Wiley Periodicals, Inc.
Inheriting a structural scaffold for Golgi biosynthesis
Authors: Jesch Stephen A. 
Published: October 2002

AbstractIn animal cells, the Golgi complex undergoes reversible disassembly during mitosis. The disassembly/reassembly process has been intensively studied in order to understand the mechanisms that govern organelle assembly and inheritance during cell division. A long‐standing controversy in the field has been whether formation of Golgi structure is template‐mediated or self‐organizes from components of the endoplasmic reticulum. A recent study1 however, has demonstrated that a subset of proteins that form a putative Golgi matrix can be inherited during cell division in the absence of membrane input from the endoplasmic reticulum. The outcome of this study suggests that a templating mechanism for the formation of Golgi structure may exist. This study has important implications for understanding mechanisms that govern Golgi biogenesis. BioEssays 24:584–587, 2002. © 2002 Wiley Periodicals, Inc.
Regulation by transcription attenuation in bacteria: how RNA provides instructions for transcription termination/antitermination decisions
Authors: Henkin Tina M. , Yanofsky Charles 
Published: October 2002

AbstractRegulation of gene expression by premature termination of transcription, or transcription attenuation, is a common regulatory strategy in bacteria. Various mechanisms of regulating transcription termination have been uncovered, each can be placed in either of two broad categories of termination events. Many mechanisms involve choosing between two alternative hairpin structures in an RNA transcript, with the decision dependent on interactions between ribosome and transcript, tRNA and transcript, or protein and transcript. In other examples, modification of the transcription elongation complex is the crucial event. This article will describe and compare several of these regulatory strategies, and will cite specific examples to illustrate the different mechanisms employed. BioEssays 24:700–707, 2002. © 2002 Wiley Periodicals, Inc.
FTIR spectroscopic method for detection of cells infected with herpes viruses
Authors: Salman Ahmad , Erukhimovitch Vitaly , Talyshinsky Marina , Huleihil Mahmoud , Huleihel Mahmoud 
Published: October 2002

AbstractMicroscopic FTIR spectroscopy was used to investigate the spectral differences between normal cells in culture and cells infected with various members of the herpes family of viruses [Herpes simplex (HSV) and Varicella zoster (VZV)]. The main objective of this study is to evaluate the possibility of developing microscopic FTIR spectroscopy as a sensitive assay for the detection of herpetic infections at their early stages. The advantage of this method over conventional FTIR spectroscopy is that it facilitates inspection of restricted regions of tissue. Our results showed significant and consistent differences between all normal and HSV or VZV infected cells that were tested. Detectable and significant spectral differences between normal and infected cells are seen as early as 24 h postinfection, but the damage of the cells (cytopathic effect), caused by the infecting virus, can be seen by optical microscope observations at only 3 days postinfection. An impressive increase in the levels of vital cellular metabolites was seen in the herpes virus infected cells compared to normal cells. It seems that this spectral behavior is unique for infection with herpes viruses, because when these cells were infected with other viruses from different families like retroviruses, a considerable decrease in the levels of vital cellular metabolites was seen in infected cells compared to normal cells. Cluster analysis performed on FTIR mass chromatography yielded 100% accuracy in classifying control uninfected and VZV or HSV infected cells. Our data strongly support the possibility of developing FTIR microscopy as a diagnostic method for early detection of herpetic infections. © 2002 Wiley Periodicals, Inc. Biopolymers (Biospectroscopy) 67: 406–412, 2002
The response of GS‐NS0 myeloma cells to single and multiple pH perturbations
Authors: Osman Jason J. , Birch John , Varley Julie 
Published: October 2002

AbstractAnimal cells are cultured in several types of vessels at laboratory and industrial scale the most common being the stirred tank and the air‐lift. Economically, it is preferable to culture animal cells at the largest possible scale but the perceived sensitivity of animal cells to hydrodynamic shear has, until now, limited the aeration and agitation rates used. This has been reported to cause inhomogeneities in operational parameters such as dissolved oxygen concentration, temperature and pH. pH is of special interest during the latter stages of many animal cell fermentation because alkali additions, used for pH control, can cause large local pH perturbations of varying size and duration. The effect of single and multiple pH perturbations on the cell growth of a widely used GS‐NS0 mouse myeloma cell line grown in batch culture was investigated. The effect of perturbation amplitude and duration was investigated using a single stirred tank reactor (STR). In the single STR system cells were subjected to one pH 8.0 or 9.0 perturbation ranging in duration from 0–90 minutes. No measurable decrease in viable cell number was seen for pH 8.0 perturbations of any duration whereas pH 9.0 perturbations lasting for 10 minutes caused a 15% decrease in viable cell number. The proportion of viable cells decreased with increasing perturbation time and a 90‐minute exposure killed all of the cells. The effect of multiple pH perturbations on GS‐NS0 cells was investigated using two connected STR's. More specifically the number of perturbations and the perturbation frequency were investigated. Cells were subjected to between 0 and 100 perturbations at pH 8.0; the time between each perturbation (frequency) was 6 minutes and each perturbation lasted for 200 seconds. Viable cell number decreased with increasing perturbation number, with 100 perturbations causing death of 27.5% of cells. Cells were also exposed to 10 perturbations at pH 9.0, each of 200 second duration at frequencies of either 6, 18 or 60 minutes. Approximately 8 times more cells were killed with perturbations at a 6‐minute frequency (28.3% cell death) than at a 60‐minute frequency (3.4% cell death). © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 398–407, 2002.
Application of a pore‐blockage—Cake‐filtration model to protein fouling during microfiltration
Authors: Palacio Laura , Ho Chia‐Chi , Zydney Andrew L. 
Published: October 2002

AbstractAlthough protein fouling is a critical factor governing the performance of microfiltration systems, there have been relatively few studies comparing the fouling behavior of different proteins. Flux‐decline data were obtained for the filtration of bovine serum albumin, lysozyme, pepsin, immunoglobulin G, and myoglobin through polycarbonate track‐etch membranes. The data were analyzed using a recently developed model that accounts for simultaneous pore blockage and cake formation. The model was in very good agreement with the data for all five proteins, demonstrating the general applicability of this new theoretical framework. The initial fouling due to pore blockage is directly related to the concentration of protein aggregates in solution, which was measured independently by quasi‐elastic light scattering. The results provide important insights into the mechanisms of protein fouling during microfiltration. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 260–270, 2002.
High‐gradient magnetic affinity separation of trypsin from porcine pancreatin
Authors: Hubbuch Jürgen J. , Thomas Owen R. T. 
Published: October 2002

AbstractWe introduce a robust and scale‐flexible approach to macromolecule purification employing tailor‐made magnetic adsorbents and high‐gradient magnetic separation technology adapted from the mineral processing industries. Detailed procedures for the synthesis of large quantities of low‐cost defined submicron‐sized magnetic supports are presented. These support materials exhibit unique features, which facilitate their large‐scale processing using high magnetic field gradients, namely sufficiently high magnetization, a relatively narrow particle size distribution and ideal superparamagnetism. Following systematic optimization with respect to activation chemistry, spacer length and ligand density, conditions for preparation of effective high capacity (Qmax = 120 mg g−1) strongly interacting (Kd < 0.3 μm) trypsin‐binding adsorbents based on immobilized benzamidine were established. In small‐scale studies ≈95% of the endogenous trypsin present in a crude porcine pancreatin feedstock was recovered with a purification factor of ≈4.1 at the expense of only a 4% loss in α‐amylase activity. Efficient recovery of trypsin from the same feedstock was demonstrated at a vastly increased scale using a high‐gradient magnetic separation system to capture loaded benzamidine‐linked adsorbents following batch adsorption. With the aid of a simple recycle loop over 80% of the initially adsorbed trypsin was recovered in‐line with an overall purification factor of ≈3.5. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 301–313, 2002.
Polymer surfaces derivatized with poly(vinyl‐N‐hexylpyridinium) kill airborne and waterborne bacteria
Authors: Tiller Joerg C. , Lee Sang Beom , Lewis Kim , Klibanov Alexander M. 
Published: October 2002

AbstractA facile methodology has been developed for covalently derivatizing the surfaces of common materials with a designed antibacterial polycation, poly(vinyl‐N‐pyridinium bromide), wherein the first, key step involves surface coating with a nanolayer of silica. Various commercial synthetic polymers derivatized in this manner become bactericidal—they kill up to 99% of deposited, from either an aerosol or an aqueous suspension, Gram‐positive and Gram‐negative bacteria on contact. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 465–471, 2002.
Affinity separation using an Fv antibody fragment–“smart” polymer conjugate
Authors: Fong Robin B. , Ding Zhongli , Hoffman Allan S. , Stayton Patrick S. 
Published: October 2002

AbstractPoly(N‐isopropylacrylamide), or PNIPAAm, is considered a “smart” polymer because it sharply precipitates when heated above a critical temperature, about 32°C in water, and redissolves when cooled. Conjugates made of PNIPAAm and IgG antibodies also exhibit the same critical temperature behavior. Interestingly, antigens that are complexed with these conjugates can also be phase‐separated along with the conjugates. In this work, we conjugated PNIPAAm for the first time to the immunoglobulin Fv fragment, the smallest fragment of an antibody that still retains the antigenic affinity of the whole antibody. For our studies, we used an Fv fragment that strongly binds hen egg white lysozyme (HEL). The purified Fv fragment–polymer conjugate precipitated at the same temperature as did the pure polymer. After addition of the conjugate to a mixture containing HEL and after thermal separation of the conjugate at 37°C, the amount of HEL in solution was reduced by as much as 80%. We were able to demonstrate the reversibility of the separation through three cycles of precipitation and dissolution. It was also possible to recover free HEL by thermal separation of the conjugate in the presence of an eluant, 50 mM diethylamine. The conjugate can then be recycled for second use. In conclusion, immunoseparations can be performed using smart polymer conjugates made with just the variable domains of an antibody. Unlike whole antibodies, fragments of antibodies can be produced in Escherichia coli, allowing easier genetic engineering of the antibody and tailoring of the conjugate. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 271–276, 2002
Modeling aerobic carbon source degradation processes using titrimetric data and combined respirometric–titrimetric data: Structural and practical identifiability
Authors: Gernaey Krist , Petersen Britta , Dochain Denis , Vanrolleghem Peter A. 
Published: October 2002

AbstractThe structural and practical identifiability of a model for description of respirometric–titrimetric data derived from aerobic batch substrate degradation experiments of a CxHyOzcarbon source with activated sludge was evaluated. The model processes needed to describe titrimetric data included substrate uptake, CO2production, and NH3uptake for biomass growth. The structural identifiability was studied using the Taylor series method and a recently proposed generalization method. It showed that combining respirometric and titrimetric data allows structural identifiability of one extra parameter combination, the biomass yield,YH, compared to estimation on separate data sets, on condition that the nitrogen fraction in biomass (iXB) is known. However, data from short‐term batch substrate degradation experiments were not sufficiently informative to allow practical identification of all structurally identifiable parameters. Combining respirometry and titrimetry resulted in improvements of parameter confidence intervals compared to estimation on separate respirometric or titrimetric data sets. However, the level of the improvement seems to be substrate dependent: parameter confidence intervals improved considerably more for dextrose than for acetate degradation models. Noteworthy is the finding that the half‐saturation substrate concentrations can be different depending on whether they are estimated from respirometric or titrimetric data. Moreover, this difference appears to be dependent on the carbon source considered: for dextrose, titrimetry‐basedKSvalues are higher than respirometry‐based values while for acetate the opposite was found. It was hypothesized that this can be explained by the different point in cell metabolism where the proton production or consumption takes place, leading to a corresponding difference in timing between pH effect and oxygen consumption. Finally, the biomass yieldYHand the nitrogen content of the biomassiXBcould be estimated from combined respirometric–titrimetric data obtained with addition of a known amount of carbon source.YHcan also be estimated fromrOdata when the initial substrate concentrationSS(0) is known. The values found correspond to values reported in literature, but, interestingly, also seem able to reflect the occurrence of storage processes when pulses of acetate and dextrose are added. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 754–767, 2002.
Intracellular expression of Vitreoscilla hemoglobin modifies microaerobic Escherichia coli metabolism through elevated concentration and specific activity of cytochrome o
Authors: Tsai Philip S. , Nägeli Michael , Bailey James E. 
Published: October 2002

AbstractThe function of the reversible oxygen‐binding hemoprotein from Vitreoscilla (VHb), which enhances oxygen‐limited cell growth and recombinant protein production when functionally expressed in Escherichia coli, was investigated in wild‐type E. coli and in E. coli mutants lacking one of the two terminal oxidases, cytochrome o complex (aerobic terminal oxidase, Cyo) or cytochrome d complex (microaerobic terminal oxidase, Cyd). Deconvolution of VHb, cytochrome o, and cytochrome d bands from in vivo absorption spectra revealed a 5‐fold enhancement in cytochrome o content and a 1.5‐fold increment in cytochrome d by VHb under microaerobic environments (dissolved oxygen less than 2% air saturation). Based upon oxygen uptake kinetics measurements of these mutants, the apparent oxygen affinity of the Cyo+, Cyd− E. coli was increased in the presence of VHb, but no difference in the apparent Km was observed for the Cyo−, Cyd+ strain. Results suggest that the expression of VHb in E. coli increases the level and activity of terminal oxidases and thereby improves the efficiency of microaerobic respiration and growth. © 2002 Wiley Periodicals, Inc. Biotechnol Bioeng 79: 558–567, 2002.
The role of proxies in treatment decisions: evaluating functional capacity to consent to end‐of‐life treatments within a family context
Authors: Allen Rebecca S. , Shuster John L. 
Published: October 2002

AbstractPsychology as a profession has entered the arena of palliative and hospice care later in the process than other health care professions. Through the use of Familial Advance Planning Evaluations (FAPEs), however, psychologists can assist individuals and families in facing end‐of‐life transitions in important ways. Hospice and palliative care philosophy treats the patient and family as the unit of care. End‐of‐life decision‐making is therefore a family matter as well as a normative developmental transition. Yet, little is known about the decision‐making process. This paper reviews the literature regarding informed consent, advance care planning, and proxy decision‐making and outlines a theoretical model for familial decision‐making. Previous models of end‐of‐life capacity evaluations and family assessments are presented and serve as the basis for a comprehensive assessment of familial decision‐making at the end of life. Functional capacity evaluations of individuals at the end of life regarding decisions about life‐sustaining medical treatments enable both the individual patient and one identified proxy from his or her family to discuss important issues families may face during medical crises at the end of life. The information gleaned from such evaluations has the potential to assist psychologists and other professionals in designing family‐specific interventions to reduce caregiving distress, improve quality of life for dying patients, and ease the transition to bereavement for caregivers. Copyright © 2002 John Wiley & Sons, Ltd.
Legal implications for failure to comply with advance directives: an examination of the incompetent individual's right to refuse life‐sustaining medical treatment
Authors: Perry Sherynn J. 
Published: October 2002

AbstractLife‐sustaining medical technology in the past century has created a growing body of case law and legislation recognizing the incompetent individual's right to make his or her own end‐of‐life decisions. This article focuses on California's leadership in the area of these specific end‐of‐life issues: specifically, exploring the right of an incompetent individual to refuse life‐sustaining medical treatment. The article examines advance directives along with various judicial decision‐making standards for incompetent individuals and explores the sociobehavioral and legal rationale for compliance with incompetent individual's rights to make end‐of‐life decisions. Finally this article concludes (i) that advance directives allow competent individuals to state the medical treatment they would prefer in the event they should later become incompetent and (ii) that when advance directives are properly executed in a detailed manner, under laws currently in effect in some jurisdictions, the preferences stated in the directive bind health care providers. Copyright © 2002 John Wiley & Sons, Ltd.
Reinterpreting the controlled substances act: predictions for the effect on pain relief
Authors: Werth James L. 
Published: October 2002

AbstractOn November 6, 2001 U.S. Attorney General Ashcroft reinterpreted the Controlled Substances Act in a manner consistent with the Pain Relief Promotion Act, a bill introduced in the last Congress. This reinterpretation criminalizes actions related to the provision of controlled substances (e.g. opioids, barbiturates) in the event that a patient dies and external observers believe the intent of providing the medication was to hasten the patient's death. This paper analyzes the arguments regarding the need for reinterpretation and the potential consequences of such an action on pain relief. The conclusion is that the weight of the data clearly leads to the prediction that this reinterpretation of the Controlled Substances Act will lead physicians to be less likely to provide adequate types and doses of pain medication to patients who may die. Copyright © 2002 John Wiley & Sons, Ltd.
Rethinking justice
Authors: Small Mark A. , Kimbrough‐Melton Robin 
Published: October 2002

AbstractChanges in the way people marry, bear children and live together, combined with the changing nature of support for families, has put pressure on the justice system to adjust to new family and community realities in order to accomplish justice goals. Although the entire legal system is implicated by the changing nature of families and communities, most scholars and practitioners have focused on the judicial system and those courts most relevant to family issues: namely, the juvenile, family, and criminal courts. As scholars and practitioners began to ‘rethink justice,’ whole new reform movements of therapeutic jurisprudence, restorative justice, and community justice (among others) have emerged to offer new paradigms for the administration of justice. In this essay we discuss ways in which families and the justice system interact to strengthen and weaken each other to accomplish justice goals. Copyright © 2002 John Wiley & Sons, Ltd.
Youth prostitution: a literature review
Authors: Cusick Linda 
Published: October 2002

AbstractThis article reviews the academic literature on young people involved in prostitution. The prevalence and aetiology of youth prostitution and its links with drug use and criminal careers are explored. It argues that whatever the power of personal experiences which incline a person towards prostitution, prostitution can still only be possible in specific cultural conditions. The phenomenon of prostitution has the sexual double standard, poverty and an unequal labour market as prerequisites. We should not expect prostitution to either disappear or occur with equal frequency in men and women while these aspects of inequality continue. This article reviews debates on the particular challenges for service delivery and working together with this vulnerable group. In a civilized society, we should organize that the burden of inequalities which underlie prostitution should not be carried by children. Copyright © 2002 John Wiley & Sons, Ltd.