bluuebunny/crossref_metadata_2025 huggingface dataset:
Temporal effects of cell adhesion on mechanical characteristics of the single chondrocyte
Authors: Huang Wei , Anvari Bahman , Torres Jorge H. , Lebaron Richard G. , Athanasiou Kyriacos A.
Published: December 2002

Cell adhesion to material surfaces is a fundamental phenomenon in tissue response to implanted devices, and an important consideration in tissue engineering. For example, elucidation of phenomena associated with adhesion of chondrocytes to biomaterials is critical in addressing the difficult problem of articular cartilage regeneration. The first objective of this study was to measure the mechanical adhesiveness characteristics of individual rabbit articular chondrocytes as a function of seeding time to provide further understanding of the cell adhesion process. The second objective was to quantify the force required to separate the plasma membrane from the underlying cytoskeleton as a function of seeding time. After culturing chondrocytes on glass coverslips for 1, 2, 4, 6 h, two biomechanical tests were performed on single chondrocytes: (i) mechanical adhesiveness measurement by the cytodetacher; and (ii) plasma membrane tether formation force measurement by optical tweezers. Cell mechanical adhesiveness increased from 231 ± 149 Pa at 1 h to 1085 ± 211 Pa at 6 h. The cell contact area with the substrata increased from 161 ± 52 μm2 at 1 h to 369 ± 105 μm2 at 6 h. The tether formation force increased from 232 ± 23 pN at 1 h to 591 ± 17 pN at 6 h. Moreover, fluorescence staining by rhodamine‐phalloidin demonstrated the process of actin spreading within the cytoskeleton from 0.5 to 6 h and allowed for measurement of cell height which was found to decrease from 12.3 ± 2.9 μm at 0.5 h to 6.2 ± 0.9 μm at 6 h.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Bimodal upregulation of glial cell line‐derived neurotrophic factor (GDNF) in the neonatal rat brain following ischemic/hypoxic injury
Authors: Ikeda Tomoaki , Koo Heasoo , Xia Yi X. , Ikenoue Tsuyomu , Choi Ben H.
Published: December 2002

In order to delineate the spatial and temporal patterns of glial cell line‐derived neurotrophic factor (GDNF) expression following ischemic/hypoxic injury in immature and neonatal brain, GDNF protein levels and immunocytochemistry were studied in rats subjected to a modified Levine procedure. Significant upregulation of GDNF protein occurred in a bimodal fashion in the damaged left cerebral cortex and hippocampus, while the levels in the right cerebral hemisphere of both control and ischemic groups remained relatively unchanged. Immunocytochemical studies indicated that the early rise in GDNF levels was most likely to be related to enhanced neuronal release of GDNF. The second rise was probably related to progressive astrogliosis that occurred in response to injury. In contrast to the lack of GDNF expression among astrocytes in normal mature brains, reactive astrocytes in the neonate appear to possess a ready capacity to express GDNF. Spatial and temporal changes in the pattern of GDNF expression following injury, as determined in this study may provide insight into the functions of GDNF in vivo and into possible therapeutic approaches toward prevention of damage or rescue of neurons following brain injury.
A peptide agonist of the neural cell adhesion molecule (NCAM), C3, protects against developmental defects induced by a teratogen pyrimethamine
Authors: Klementiev Boris , Bichevaja Natalia , Novikova Tatiana , Chebotar Nikolaj , Bock Elisabeth , Berezin Vladimir
Published: December 2002

The neural cell adhesion molecule, NCAM, not only plays an important role in neuronal migration, differentiation and formation of connections in the developing nervous system, but also in the condensation of the mesodermal mesenchyme of the limb bud. Therefore, NCAM may be regarded as a target molecule for preventive strategies aimed at minimizing the effects of teratogens affecting the prenatal development of the nervous system and the skeleton. Treatment of fetuses with the teratogen pyrimethamine results in a reduced body weight, microcephaly and malformations of the hind limbs and forelimbs, e.g. micromelia, brachydactyly and adactyly. We here show that a peptide agonist of NCAM, C3, partly prevented the defects induced by this treatment. Although intra‐amniotic administration of C3 at gestational day 14 had no effect on the pyrimethamine‐induced reduction in body weight, it rescued the deficit in brain weight (microcephaly), partly reversed a decrease in thickness of the cortical plate, and significantly reduced the number of malformed fetuses. In vitro, C3 promoted survival of PC12‐E2 cells treated with pyrimethamine. Since C3 is a peptide mimetic of NCAM, our data strongly suggest that stimulating of NCAM results in neuroprotection in vivo and in vitro.
Efficacy of a homeopathic Crataegus preparation compared with usual therapy for mild (NYHA II) cardiac insufficiency: results of an observational cohort study
Authors: Schröder D. , Weiser M. , Klein P.
Published: December 2002

Objectives:

To compare the efficacy of the homeopathic Crataegus preparation Cralonin for non‐inferiority to standard treatment for mild cardiac insufficiency.

Methods:

Multicentre non‐randomised cohort study in patients aged 50–75 years in New York Heart Association class II. Patients received Cralonin (n=110) or ACE inhibitor/diuretics (n=102) for 8 weeks. To adjust for confounding by baseline factors, populations were stratified according to propensity score. After adjusting, there were no statistically significant differences between treatment groups. Treatment efficacy was assessed on 15 variables. A stringent non‐inferiority criterion for the upper limit of the 97.5% one‐sided confidence interval of the treatment difference was set to 0.2× the standard deviation (S.D.).

Results:

Both treatment regimens improved scores on most variables studied, with the greatest effect on double product after exercise (average score reduction 15.4% with Cralonin vs. 16.0% for the control group). Stringent non‐inferiority of Cralonin was demonstrated on 7 variables. Medium‐stringent (0.5×S.D.) non‐inferiority was indicated by 13 variables (exceptions: systolic blood pressure (BP) during exercise and diastolic BP at rest; for these, differences between treatments were not significant). Both treatments were well tolerated.

Conclusion:

The Crataegus‐based preparation Cralonin is non‐inferior to usual ACE inhibitor/diuretics treatment for mild cardiac insufficiency on all parameters except BP reduction.
Laser Refractive Surgery: Technological Advance and Tissue Response
Authors: Bansal Aashish K. , Veenashree M.P.
Published: December 2002

Photorefractive keratectomy (PRK) and laser assisted in situ keratomileusis (LASIK), using an excimer laser, are the currently popular techniques of correcting refractive errors. Since these techniques work by selective ablation of corneal stroma, the tissue healing response plays a great role in the ultimate outcome of surgery. Also, various methods of wound healing modulation can be used to achieve better results. While these procedures do lead to a decrease in dioptric power and increase in unaided visual acuity, higher visual functions like contrast sensitivity can sometimes be compromised after the surgery.
The Ocular Lens Epithelium
Authors: Bhat Suraj P.
Published: December 2002

An adult lens contains two easily discernible, morphologically distinct compartments, the epithelium and the fiber-cell mass. The fiber-cell mass provides the lens with its functional phenotype, transparency. Metabolically, in comparison to the fiber cells the epithelium is the more active compartment of the ocular lens. For the purposes of this review we will only discuss the surface epithelium that covers the anterior face of the adult ocular lens. This single layer of cells, in addition to acting as a metabolic engine that sustains the physiological health of this tissue, also works as a source of stem cells, providing precursor cells, which through molecular and morphological differentiation give rise to fiber cells. Morphological simplicity, defined developmental history and easy access to the experimenter make this epithelium a choice starting material for investigations that seek to address universal questions of cell growth, development, epithelial function, cancer and aging. There are two important aspects of the lens epithelium that make it highly relevant to the modern biologist. Firstly, there are no known clinically recognizable cancers of the ocular lens. Considering that most of the known malignancies are epithelial in origin this observation is more than an academic curiosity. The lack of vasculature in the lens may explain the absence of tumors in this tissue, but this provides only a teleological basis to a very important question for which the answers must reside in the molecular make-up and physiology of the lens epithelial cells. Secondly, lens epithelium as a morphological entity in the human lens is first recognizable in the 5th–6th week of gestation. It stays in this morphological state as the anterior epithelium of the lens for the rest of the life, making it an attractive paradigm for the study of the effects of aging on epithelial function. What follows is a brief overview of the present status and lacunae in our understanding of the biology of the lens epithelium.
ASSESSING ORGANIZATIONAL KNOWLEDGE CREATION THEORY IN COLLABORATIVE R&D PROJECTS
Authors: JOHNSON WILLIAM H. A.
Published: December 2002

The paper describes research from an intensive study of technological innovation in collaborative research and development (R&D) projects. Specifically, the factors of organizational knowledge creation presented by Nonaka and Takeuchi are extended into the inter-organizational realm by examining survey results of 25 collaborative R&D projects. A case study is also presented from a set of six in-depth cases from the study's population of projects. It was found that specification of goals and scanning of relevant environment factors were significant positive factors in successful technological innovation in this context. In general, the results presented in this paper indicate that inter-organizational collaboration in R&D may require different technical knowledge-creating factors or enabling conditions from the single organization situation. Practical and theoretical implications regarding the use of such managerial devices in successful technical knowledge creation strategies are also discussed.
MANAGEMENT INNOVATION ANALYSIS FOR TRANSITION ECONOMIES: METHODOLOGICAL ISSUES AND SYSTEM OF MEASURES
Authors: ILYSHEV ANATOLY M. , KOUZOUBOV SERGUEI A.
Published: December 2002

An innovation analysis in conditions of transition economy is the important means of diagnosing a firm's management. This paper presents a view of authors on solving some of the important methodological issues of the innovation analysis application. The proposed system of analytical parameters includes characteristics of a scientific and technical standard of innovations, an innovation process and the efficiency of innovation activity. The parameters of competitiveness (for 1st group), innovation activity (for 2nd group) and market diffusion (for 3rd group) are emphasized. In addition, 5-6 local parameters-characteristics of innovation activity are included in each group. The proposed parameters are segregated by the three stages of innovation activity: innovation creation, innovation deployment (application) and innovation output production.
Frequent occurrence of BCL6 rearrangements in nodular lymphocyte predominance Hodgkin lymphoma but not in classical Hodgkin lymphoma
Authors: Wlodarska Iwona , Nooyen Peet , Maes Brigitte , Martı́n-Subero José I. , Siebert Reiner , Pauwels Patrick , De Wolf-Peeters Chris , Hagemeijer Anne
Published: December 2002

We studied the genomic status of BCL6 in 23 cases of nodular lymphocyte predominance Hodgkin lymphoma (NLPHL) and 40 cases of classical Hodgkin lymphoma (cHL), using dual-color interphase fluorescence in situ hybridization (FISH). The BCL6rearrangement was identified in 48% of NLPHL cases and was not detected in cHL cases. As a confirmation, sequential or simultaneous immunohistochemistry (IHC) and FISH using CD20 or BCL6 antibodies and BCL6 DNA probes was performed in 8 NLPHL cases. The BCL6-associated translocations, t(3;22)(q27;q11), t(3;7)(q27;p12), and the most probable t(3;9)(q27;p13), were identified in 3 cases. A consistent expression of BCL6 protein in popcorn cells with the highest number of intensely stained cells in cases with a genomic BCL6rearrangement was shown by IHC. These findings support the hypothesis of a germinal center B cell–derived origin of NLPHL, indicate a significant role of BCL6 in the pathogenesis of NLPHL, and provide further evidence of the genetic diversity underlying the pathogenesis of NLPHL and cHL.
Mechanoregulation of human articular chondrocyte aggrecan and type II collagen expression by intermittent hydrostatic pressure in vitro
Authors: Ikenoue Takashi , Trindade Michael C. D. , Lee Mel S. , Lin Eric Y. , Schurman David J. , Goodman Stuart B. , Smith R. Lane
Published: December 2002

This study addressed the hypothesis that duration and magnitude of applied intermittent hydrostatic pressure (IHP) are critical parameters in regulation of normal human articular chondrocyte aggrecan and type II collagen expression. Articular chondrocytes were isolated from knee cartilage and maintained as primary, high‐density monolayer cultures. IHP was applied at magnitudes of 1, 5 and 10 MPa at 1 Hz for durations of either 4 h per day for one day (4 × 1) or 4 h per day for four days (4 × 4). Total cellular RNA was isolated and analyzed for aggrecan and type II collagen mRNA signal levels using specific primers and reverse transcription polymerase chain reaction (RT‐PCR) nested with beta‐actin primers as internal controls. With a 4 × 1 loading regimen, aggrecan mRNA signal levels increased 1.3‐ and 1.5‐fold at 5 and 10 MPa, respectively, relative to beta‐actin mRNA when compared to unloaded cultures. Changing the duration of loading to a 4 × 4 regimen increased aggrecan mRNA signal levels by 1.4‐, 1.8‐ and 1.9‐fold at loads of 1, 5 and 10 MPa, respectively. In contrast to the effects of IHP on aggrecan, type II collagen mRNA signal levels were only upregulated at loads of 5 and 10 MPa with the 4 × 4 loading regimen. Analysis of cell‐associated protein by western blotting confirmed that IHP increased aggrecan and type II collagen in chondrocyte extracts. These data demonstrate that duration and magnitude of applied IHP differentially alter chondrocyte matrix protein expression. The results show that IHP provides an important stimulus for increasing cartilage matrix anabolism and may contribute to repair and regeneration of damaged or diseased cartilage.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
The use of specific chondrocyte populations to modulate the properties of tissue‐engineered cartilage
Authors: Waldman Stephen D. , Grynpas Marc D. , Pilliar Robert M. , Kandel Rita A.
Published: December 2002

Tissue engineering of articular cartilage is a promising alternative to the conventional approaches for cartilage repair. However, recent attempts to develop articular cartilage in vitro have proven to be difficult. The tissue formed in vitro may not accumulate enough extracellular matrix, and the resulting mechanical properties are only a fraction of the native tissue. We investigated whether using specific populations of chondrocytes would improve the properties of the cartilaginous tissue that was generated in vitro. Full‐thickness (FT), mid‐and‐deep zone (MD), and deep‐zone (DEEP) chondrocytes were isolated, placed on the surface of porous ceramic substrates and maintained in culture for eight weeks. Tissue developed from DEEP chondrocytes was thicker (FT: 0.94 ± 0.03, MD: 0.88 ± 0.04, DEEP: 2.4 ± 0.1 mm) and had accumulated larger amounts of extracellular matrix (FT: 1.61 ± 0.05, MD: 1.5 ± 0.1, DEEP: 3.8 ± 0.2 mg dry weight) than the tissues formed by the FT and MD chondrocytes. The tissue formed by the FT chondrocytes accumulated the greatest amount of collagen (FT: 211 ± 14, MD: 185 ± 8, DEEP: 178 ± 5 μg/mg dry weight) whereas the tissue formed by the MD chondrocytes accumulated significantly more proteoglycans (FT: 198 ± 10, MD: 265 ± 10, DEEP: 215 ± 5 μg/mg dry weight). Interestingly, MD chondrocytes produced tissue that had compressive mechanical properties up to four times greater than the cartilaginous tissues formed by cells from either the FT or DEEP of cartilage. Thus, a combined population of intermediate and DEEP chondrocytes might be more suitable for the tissue engineering of articular cartilage.

© 2002 Orthopaedic Research Society. Published by Elsevier Science Ltd. All rights reserved.
Information provided by the skeletal muscle and associated neurons is necessary for proper brain development
Authors: Kablar Boris , Rudnicki Michael A.
Published: December 2002

Previously, motor cortex of term Myf5−/−:MyoD−/− fetuses (e.g. have ablated skeletal myogenesis and consequent early loss of lower motor and proprioceptive neurons) was found to lack giant pyramidal cells. We further investigated how the absence of the extrinsic stimuli from the lacking structures influences brain development. Apparently normal motor cortex of mutant fetuses was found to have dramatically reduced presence of nestin‐expressing processes of neural precursors, calretinin‐expressing pyramidal neurons and calbindin‐expressing neurons. Consistently, some areas of the extrapyramidal tract had significantly decreased number of differentiated neurons in mutant brains. Surprisingly, we were unable to detect any change in proliferation or cell death in the mutant neuroepithelium. Together, it appears that the information provided by the lacking structures influences the ratios of the differentiated neuronal types and their progenitor cells.
Influence of neurotrophins on the synaptogenesis of inner hair cells in the deaf Bronx waltzer (bv) mouse organ of Corti in culture
Authors: Sobkowicz Hanna M. , August Benjamin K. , Slapnick Susan M.
Published: December 2002

The Bronx waltzer (bv) deaf mouse is characterized by massive degeneration of the primary auditory receptors, the inner hair cells, which occurs during the time of expected afferent synaptogenesis. The process is associated with degeneration and protracted division of the normally postmitotic afferent spiral ganglion neurons. To investigate the potential role of neurotrophins in the afferent synaptogenesis of inner hair cells, we exposed bv newborn cochleas in organotypic culture to brain‐derived neurotrophic factor (BDNF), neurotrophin‐3 (NT‐3) and nerve growth factor (NGF), and also to gamma aminobutyric acid (GABA), for up to 8 days. The study was done using light and electron microscopy. Only about 20% of the inner hair cells survived in culture, regardless of the treatment, similar to the number in the intact mutant in our colony. Depending on the exogenous treatment, this population consisted of either innervated ultrastructurally normal cells or denervated dedifferentiated cells wrapped—in lieu of nerve endings—by the supporting inner phalangeal and border cells. In the control and GABA cultures, inner hair cells were mostly denervated. BDNF and NT‐3 alone or combined increased synaptogenesis and hair cell survival only during the first 3 days (by about 10%); however, the cells became denervated by 8 postnatal (PN). Only NGF induced stable innervation and differentiation of neurosensory relationships, including supernumerary innervation characteristic of the intact bv. Denervation among the remaining 20% of inner hair cells induced a reactive wrapping by inner phalangeal and border cells which evidently extended inner hair cell survival. Immunocytochemical studies of these reactive supporting cells were done in the intact (8 PN) mutant cochlea. The supporting cells that provide sustenance to the denervated inner hair cells displayed strong BDNF (and possibly NT‐3) immunoreactivity. Subsequently, we revealed the presence of all three neurotrophins in the inner hair cell region of the developing (1–8 PN) cochlea of the normal ICR mouse. The inner hair cells expressed all three neurotrophins; BDNF prevailed in the inner phalangeal cells, NT‐3 in the pillar cells and inner phalangeal cells, and NGF in the pillar cells. In conclusion: initially, the 80% loss of inner hair cells is apparently caused by their failed afferent synaptogenesis. Exogenous neurotrophins influence synaptogenesis in the bv in culture, but NGF alone is successful in promoting stable neurosensory relationships. The presence of neurotrophins in supporting cells in the normal and degenerating cochlea indicates their role in the sustenance of inner hair cells.
INTRODUCING EXISTING FINANCIAL SERVICES OVER NEW ELECTRONIC CHANNELS
Authors: MATTILA MINNA
Published: December 2002

Innumerable cases and much research have been reported about the launching of new innovative products over existing distribution channels, where a misfire may kill the new product. Much less seems to be known about the introduction of existing products via new channels, regardless of the fact that a backfire here can kill the product both in the new and the old channels and leave an established firm without any business. Over the last two decades, banks have transferred their products from branch offices to new electronic fixed-line and mobile channels. This article will outline some findings about the Finnish banks' experience in managing the introduction of existing products via new channels. The main aim of this paper is to make recommendations for managing the move to new electronic channels.
Conference Report: WORKSHOP ON "LINKING IMPACT ASSESSMENT AND MANAGEMENT TOOLS"
Authors: SHEATE WILLIAM R.
Published: December 2002

As the concepts associated with sustainable development mature, and new and modified decision aiding tools are developed, so links between environmental assessment and management tools become all the more essential. Increasingly there is experience of trying to make links between tools, e.g. EIA/SEA and EMS, LCA and SEA, SEA and sustainability appraisal etc. The purpose of this workshop was to exchange experience and to discuss theoretical and practical linkages between tools that can be made and further developed.
Removing risk from safe motherhood
Authors: Rohde J.E.
Published: December 2002

It is necessary to differentiate between complications of pregnancy and population risk groups for those complications. The latter have limited use as most complications occur in the low risk groups. Complications of pregnancy need to be treated in health facilities that can provide blood transfusions, cesarean section, removal of placenta and induction of labor. A plan must exist for each pregnant woman to be moved to such a facility, since it is not possible to predict who will have the complication. Early detection and effective treatment of complications and family planning services to prevent unwanted pregnancies is the way to lower maternal mortality.
The impact of unregulated fertility on maternal and child survival
Authors: Senanayake P.
Published: December 2002

Almost all maternal and child deaths represent merely the endpoint of the ‘road to death’ — a combination of factors that include high‐risk pregnancy, socioeconomic disadvantage and inadequate health care. Unregulated fertility is the underlying cause of most high‐risk pregnancies. They are: unwanted; in mothers younger than 20 or older than 35; closely spaced; and in women who already have several children. The resulting morbidity and mortality create a cycle of further disadvantage, further increases in child mortality and further high‐risk pregnancies. Family planning is the single most important exit from the ‘road to death.’ Over the past 40 years it has contributed to the worldwide reduction in child mortality, and for every 100 women provided with family planning, a woman's life is saved.
Eclampsia: modern outlook on prevention and treatment
Authors: Hussain M.A.
Published: December 2002

This is a review article. Eclampsia is an almost preventable condition. The ratio of prostacycline and thromboxane is reversed in patients with preeclampsia and eclampsia. Lipid peroxides are also increased during pregnancy and there is lack of invasion of the spiral arteries by trophoblasts, particularly the second wave. A good predictive test is urgently needed to detect patients who are at risk of developing these conditions later in their pregnancy. Low‐dose aspirin is a promising preventive therapy in this group of women. Until we have good means of preventing preeclampsia and eclampsia, supportive care in treatment must be improved. Essential obstetric care (EOC) at all levels of health services should be established to reduce maternal mortality and morbidity from this condition, and the community educated and mobilized to respond appropriately in time of need.
Midwives and the achievement of safer motherhood
Authors: Peters M.H.
Published: December 2002

The root problem of unsafe motherhood in developing countries is lack of access to a competent care‐giver throughout pregnancy, childbirth and the postpartum period. These resources, trained midwives, with or without prior nursing training, should be recruited from the communities they are to serve. Community midwives must be involved in any realistic strategic plan to provide this needed midwifery care.
Lessons learned from maternal mortality study to reduce deaths in Egypt
Authors: El‐Shafei M.
Published: December 2002

To identify causes of maternal death in Egypt and with that knowledge to effect its reduction, the Ministry of Health launched a study, a unique aspect of which was exploration of avoidable factory at home, in medical facilities, and during transportation from one to the other. The country must make better use of existing personnel and buildings.
In vivo activation of the constitutive androstane receptor β (CARβ) by treatment with dehydroepiandrosterone (DHEA) or DHEA sulfate (DHEA‐S)
Authors: Fujita Atsushi , Furutama Daisuke , Tanaka Toshifumi , Sakai Reiko , Koyama Akio , Hanafusa Toshiaki , Mitsuhashi Tomoaki , Ohsawa Nakaaki
Published: December 2002

We investigated whether dehydroepiandrosterone (DHEA) or DHEA‐sulfate (S) affected the activities of nuclear receptors, with special reference to constitutive androstane receptor β (CARβ). Administration of DHEA or DHEA‐S enhanced the DNA binding of hepatic nuclear extracts to responsive elements for the retinoic acid receptor, the retinoic acid receptor β 2 and the peroxisome proliferator activated receptor. The bound complexes were shown to be the CARβ‐RXR heterodimer by antibody‐supershift assays. The expression of a target gene of CARβ, Cyp2b10, was increased in liver by DHEA or DHEA‐S treatment, suggesting that DHEA or DHEA‐S actually activated CARβ in vivo. It was suggested that the metabolic conversion of DHEA, DHEA‐S to CARβ ligands could occur in vivo and the metabolites could regulate the expression of CARβ target gene expression. Our results provide new insights into the in vivo relationship between DHEA/DHEA‐S and CARβ activation.
A dispensable peptide from Acidithiobacillus ferrooxidans tryptophanyl‐tRNA synthetase affects tRNA binding
Authors: Zúñiga Roberto , Salazar Juan , Canales Mauricio , Orellana Omar
Published: December 2002

The activation domain of class I aminoacyl‐tRNA synthetases, which contains the Rossmann fold and the signature sequences HIGH and KMSKS, is generally split into two halves by the connective peptides (CP1, CP2) whose amino acid sequences are idiosyncratic. CP1 has been shown to participate in the binding of tRNA as well as the editing of the reaction intermediate aminoacyl‐AMP or the aminoacyl‐tRNA. No function has been assigned to CP2. The amino acid sequence of Acidithiobacillus ferrooxidans TrpRS was predicted from the genome sequence. Protein sequence alignments revealed that A. ferrooxidans TrpRS contains a 70 amino acids long CP2 that is not found in any other bacterial TrpRS. However, a CP2 in the same relative position was found in the predicted sequence of several archaeal TrpRSs. A. ferrooxidans TrpRS is functional in vivo in Escherichia coli. A deletion mutant of A. ferrooxidans trpS lacking the coding region of CP2 was constructed. The in vivo activity of the mutant TrpRS in E. coli, as well as the kinetic parameters of the in vitro activation of tryptophan by ATP, were not altered by the deletion. However, the K
m value for tRNA was seven‐fold higher upon deletion, reducing the efficiency of aminoacylation. Structural modeling suggests that CP2 binds to the inner corner of the L shape of tRNA.
Identification and characterization of single‐domain thiosulfate sulfurtransferases from Arabidopsis thaliana
Authors: Bauer Michael , Papenbrock Jutta
Published: December 2002

Sulfurtransferases/rhodaneses (ST) are a group of enzymes widely distributed in all three phyla that catalyze the transfer of sulfur from a donor to a thiophilic acceptor substrate. All ST contain distinct structural domains, and can exist as single‐domain proteins, as tandemly repeated modules in which the C‐terminal domain bears the active site, or as members of multi‐domain proteins. We identified several ST in Arabidopsis resembling the C‐terminus of the Arabidopsis two‐domain ST1 and the single‐domain GlpE protein from Escherichia coli. Two of them (accession numbers BAB10422 and BAB10409) were expressed in E. coli and purified. Both proteins showed thiosulfate‐specific ST enzyme activity.
Microbead display by in vitro compartmentalisation: selection for binding using flow cytometry
Authors: Sepp Armin , Tawfik Dan S , Griffiths Andrew D
Published: December 2002

In vitro compartmentalisation in an emulsion was used to physically link proteins to the DNA that encodes them via microbeads. These microbeads can be selected for catalysis, or, as demonstrated here, for binding. Genes encoding a peptide containing an epitope (haemagglutinin) were enriched to near purity from a 106‐fold excess of genes encoding a different peptide by two rounds of selection using flow cytometry, indicating ∼1000‐fold enrichment per round. Single beads can be isolated using flow sorting and the single gene on the bead amplified by polymerase chain reaction. Hence, the entire process can be performed completely in vitro.
Host-Defense Mechanism of the Ocular Surfaces
Authors: Sack Robert A. , Nunes Irene , Beaton Ann , Morris Carol
Published: December 2002

The defense of the ocular surfaces presents an unique challenge in that not only must integrity be maintained against microbial, inflammatory and physical assault, but it must be done while minimizing the risk of loss of corneal transparency. This puts severe limitations on the degree to which scarring or neovascularization can occur in the cornea secondary to any infectious, inflammatory, immunological or wound healing process. Moreover, this defense system must be equally effective under two extremes of conditions: those found in the open eye and the closed eye environments. It is our contention that these constraints have resulted in the evolution of a highly complex fail-safe defense system that utilizes distinctly different strategies in open and closed eye conditions. The extraordinary effectiveness of this system is evidenced by the fact that despite continued exposure to a microbe rich environment, the external ocular surfaces maintain a very low microbial titer and are highly resistant to breaching by all but a few pathogens. It is the intent of this review to provide a working model of this defense system as it operates under both open and closed eye conditions, to provide evidence in support of this model as well as highlight some of the many areas of uncertainty.
Grain‐size‐sensitive seismic wave attenuation in polycrystalline olivine
Authors: Jackson Ian , Fitz Gerald John D. , Faul Ulrich H. , Tan Ben H.
Published: December 2002

In order to investigate the processes responsible for the attenuation of seismic shear waves in the Earth's upper mantle, four olivine polycrystals ranging in mean grain size d from 3 to 23 μm have been fabricated, characterized, and mechanically tested in torsion at high temperatures and seismic frequencies. Both the shear modulus, which governs the shear wave speed VS, and the dissipation of shear strain energy Q−1 have been measured as functions of oscillation period To, temperature T, and, for the first time, grain size. At sufficiently high T all four specimens display similar absorption band viscoelastic behavior, adequately represented for 1000 < T < 1200 or 1300°C and 1 < To < 100 s, by the expression Q−1 = A [Tod−1 exp (−E/RT)]α with A = 7.5 × 102 s−α μmα, α = 0.26 and E = 424 kJ mol−1. This mildly grain‐size‐sensitive viscoelastic behavior of melt‐free polycrystalline olivine is attributed to a combination of elastically and diffusionally accommodated grain boundary sliding, the latter becoming progressively more important with increasing T and/or To. Extrapolation to the larger (mm‐cm) grain sizes expected in the Earth's upper mantle yields levels of dissipation comparable with those observed seismologically, implying that the same grain‐size‐sensitive processes might be responsible for much of the observed seismic wave attenuation. The temperature sensitivity of VS is increased substantially by the viscoelastic relaxation allowing the lateral variability of wave speeds to be associated with relatively small temperature perturbations.
Deep arid system hydrodynamics 1. Equilibrium states and response times in thick desert vadose zones
Authors: Walvoord Michelle A. , Plummer Mitchell A. , Phillips Fred M. , Wolfsberg Andrew V.
Published: December 2002

Quantifying moisture fluxes through deep desert soils remains difficult because of the small magnitude of the fluxes and the lack of a comprehensive model to describe flow and transport through such dry material. A particular challenge for such a model is reproducing both observed matric potential and chloride profiles. We propose a conceptual model for flow in desert vadose zones that includes isothermal and nonisothermal vapor transport and the role of desert vegetation in supporting a net upward moisture flux below the root zone. Numerical simulations incorporating this conceptual model match typical matric potential and chloride profiles. The modeling approach thereby reconciles the paradox between the recognized importance of plants, upward driving forces, and vapor flow processes in desert vadose zones and the inadequacy of the downward‐only liquid flow assumption of the conventional chloride mass balance approach. Our work shows that water transport in thick desert vadose zones at steady state is usually dominated by upward vapor flow and that long response times, of the order of 104–105 years, are required to equilibrate to existing arid surface conditions. Simulation results indicate that most thick desert vadose zones have been locked in slow drying transients that began in response to a climate shift and establishment of desert vegetation many thousands of years ago.
Saturn: Search for a missing water source
Authors: Jurac S. , McGrath M. A. , Johnson R. E. , Richardson J. D. , Vasyliunas V. M. , Eviatar A.
Published: December 2002

The origin of the large hydroxyl radical (OH) cloud near the inner moons of Saturn, indicative of a surprisingly large water‐vapor source, has represented a puzzle since its discovery in 1992. A new set of Hubble Space Telescope measurements is used to constrain the OH spatial densities and to pinpoint the source region. Our model indicates that the vast majority of the water vapor (>80%) originates from Enceladus's orbital distance. This may indicate the presence of a dense population of small, as of yet unseen, bodies concentrated near Enceladus; collisions between these fragments are the suggested mechanism for producing the necessary amounts of water vapor. We show that collisions between plasma ions and neutral molecules substantially inflate the OH cloud, and increase the OH loss rate, requiring a water source three times larger than previous estimates.
MANAGING MANUFACTURING ACTION PLANS
Authors: TAN KIM HUA , PLATTS KEN
Published: December 2002

In recent years, we have seen a myriad of action plans (management tools and "best practices") that are available to transform the way organisations work. The action plans could be improvement programmes such as Total Quality Management (TQM), Just in Time (JIT) or specific tools like Single Minute Exchange of Dies (SMED) for reducing tooling set-up time on a work centre. Frequently, these action plans will have an impact on more than one area of performance. This makes it increasingly hard for manufacturing managers wishing to improve their operation to identify the range of options available and decide on which to pursue. This research has sought to address this problem by developing an "action planning handbook" comprising a software tool that offers a database and network which shows the inter-relationship of the action plans and the objectives. The tool has been developed based on Burbidge's Connectance Concept. The database and network is intended to help managers to: (1) get an overall view of the action plans for a particular objective; (2) to see the inter-relationships (if any) among the action plans; and (3) select the most appropriate action. This paper describes the construction of the database and software tool, and concludes with the findings of the application of these in industrial cases.
THE ENVIRONMENTAL IMPACTS OF JAPANESE TOURISM AND LEISURE
Authors: GIELEN D. J. , KURIHARA R. , MORIGUCHI Y.
Published: December 2002

Structural change towards environmentally benign service industries is widely considered a key strategy for sustainable development. However the environmental impact of service industries is not negligible. This paper analyses the environmental impact of Japanese leisure and tourism. The methodological problems and pitfalls are discussed and a new methodological framework is elaborated. The results suggest that leisure and tourism are responsible for 17% of the national greenhouse gas emissions, and 13% of the national primary energy use. Also a considerable part of the national land use is affected by leisure and tourism. The impact on biodiversity is hard to quantify because of inadequate monitoring systems, reference definition problems and interacting causes of environmental pressure. The environmental impact diverge widely for different types of leisure and tourism activities. Given these results, the sustainability of economic growth based on leisure and tourism should be analysed more carefully.
AN EVALUATION OF THE QUALITY OF ENVIRONMENTAL IMPACT STATEMENTS IN THESSALONIKI, GREECE
Authors: CASHMORE MATTHEW , CHRISTOPHILOPOULOS EPAMINONDAS , COBB DICK
Published: December 2002

Environmental Impact Assessment (EIA) legislation was first adopted in Greece in 1979. In the intervening 23 years, competent authorities, practitioners, and developers have gained considerable experience in the practice of EIA. A previous research study conducted for the European Commission indicated, on the basis of the quality of Environmental Impact Statements (EISs) produced, that overall the nation's EIA system was performing satisfactorily. This research builds on the previous study by examining a considerably larger sample (72) of EISs produced for a diverse range of project types. Only 40% of EISs sampled were found to be of a satisfactory quality (compared to 75% in the previous study). An assessment of the performance of different elements of the EIA process indicates that descriptive tasks are, on average, performed better than scientific tasks. Consultation with stakeholder groups and their participation appears to be particularly problematic. Variables that influence the quality of EISs are identified and a number of broad recommendations are made for improving the effectiveness of the EIA system in the short and long term.
Critical switch of the metabolic fluxes by phosphofructo‐2‐kinase:fructose‐2,6‐bisphosphatase. A kinetic model
Authors: Goldstein Boris N. , Maevsky Andrey A.
Published: December 2002

A kinetic model for the bifunctional enzyme, phosphofructo‐2‐kinase:fructose‐2,6‐bisphosphatase, is analysed by application of the graph‐theoretical method, considering comparable levels for all participants. Certain elementary reactions, distributed on the enzyme surface, are considered to be co‐ordinated in a single conformational transition (a model of parallel molecular operations). The method allows us to identify in the kinetic scheme its destabilising sub‐scheme as a branched cycle of elementary reactions. Under certain conditions this sub‐scheme induces critical phenomena (bistability or oscillations). The computer calculations for the estimated parameter values fit well the experimental observations for this system. The model explains the periodic or bistable counterphase changes of the two opposing activities of this enzyme, observed after glucose perfusion of rat hepatic enzyme samples, and predicts drastic critical changes in kinetic behaviour induced by small external signals. The model also shows the necessity of the phosphoryl intermediate in the mechanism of the bisphosphatase for the critical kind of kinetic behaviour.
Introduction of a Na+/H+ antiporter gene from Atriplex gmelini confers salt tolerance to rice
Authors: Ohta Masaru , Hayashi Yasuyuki , Nakashima Asae , Hamada Akira , Tanaka Akira , Nakamura Tatsunosuke , Hayakawa Takahiko
Published: December 2002

We engineered a salt‐sensitive rice cultivar (Oryza sativa cv. Kinuhikari) to express a vacuolar‐type Na+/H+ antiporter gene from a halophytic plant, Atriplex gmelini (AgNHX1). The activity of the vacuolar‐type Na+/H+ antiporter in the transgenic rice plants was eight‐fold higher than that in wild‐type rice plants. Salt tolerance assays followed by non‐stress treatments showed that the transgenic plants overexpressing AgNHX1 could survive under conditions of 300 mM NaCl for 3 days while the wild‐type rice plants could not. These results indicate that overexpression of the Na+/H+ antiporter gene in rice plants significantly improves their salt tolerance.
A mechano‐chemical model for energy transduction in cytochrome c oxidase: the work of a Maxwell's god
Authors: Xavier António V
Published: December 2002

Cytochrome c
3 has a central role in the energetics of Desulfovibrio sp., where it performs an electroprotonic energy transduction step. This process uses a network of cooperativities, largely based on anti‐Coulomb components, resulting from a mechano‐chemical energy coupling mechanism. This mechanism provides a model coherent with the data available for the redox chemistry of haem a of cytochrome c oxidase and its link to the activation of protons. A crucial feature of the model is an anti‐Coulomb effect that sets the stage for a molecular ratchet, ensuring vectoriality for the redox‐driven localised movement of protons across the membrane, against an electrochemical gradient.
LytB protein catalyzes the terminal step of the 2‐C‐methyl‐D‐erythritol‐4‐phosphate pathway of isoprenoid biosynthesis
Authors: Altincicek Boran , Duin Evert C. , Reichenberg Armin , Hedderich Reiner , Kollas Ann-Kristin , Hintz Martin , Wagner Stefanie , Wiesner Jochen , Beck Ewald , Jomaa Hassan
Published: December 2002

Recombinant LytB protein from the thermophilic eubacterium Aquifex aeolicus produced in Escherichia coli was purified to apparent homogeneity. The purified LytB protein catalyzed the reduction of (E)‐4‐hydroxy‐3‐methyl‐but‐2‐enyl diphosphate (HMBPP) in a defined in vitro system. The reaction products were identified as isopentenyl diphosphate and dimethylallyl diphosphate. A spectrophotometric assay was established to determine the steady‐state kinetic parameters of LytB protein. The maximal specific activity of 6.6±0.3 μmol min−1 mg−1 protein was determined at pH 7.5 and 60°C. The k
cat value of the LytB protein was 3.7±0.2 s−1 and the K
m value for HMBPP was 590±60 μM.
Meltrin β mini, a new ADAM19 isoform lacking metalloprotease and disintegrin domains, induces morphological changes in neuronal cells1
Authors: Kurisaki Tomohiro , Wakatsuki Shuji , Sehara-Fujisawa Atsuko
Published: December 2002

Meltrin β (ADAM19) is a metalloprotease‐disintegrin expressed in the peripheral nervous system and other organs during embryogenesis. We report here an alternatively spliced isoform, meltrin β mini, that lacks the prodomain, metalloprotease and disintegrin domains. A comparison of the cDNA and genomic sequences suggested the existence of a new exon. This isoform was detected in murine dorsal root ganglion and neuronal cell lines by RT‐PCR. Overexpression of meltrin β mini but not meltrin β induced neurite outgrowth in neuronal cells. These studies suggest that the novel meltrin β isoform has a distinct function related to neurogenesis.
p80 ROKα binding protein is a novel splice variant of CRMP‐1 which associates with CRMP‐2 and modulates RhoA‐induced neuronal morphology
Authors: Leung Thomas , Ng Yvonne , Cheong Albert , Ng Chong Han , Tan Ivan , Hall Christine , Lim Louis
Published: December 2002

Using antibody against the Rho binding domain of ROKα, two neuronal phosphoproteins of 62 and 80 kDa were co‐immunoprecipitated from brain extracts. Peptide analysis revealed their identity as collapsin response mediator proteins (CRMPs); p62 was CRMP‐2 whereas p80 was a novel splice form of CRMP‐1 with an extended N‐terminus. p80 CRMP‐1 was able to complex with CRMP‐2, suggesting that p80 CRMP‐1 and CRMP‐2 form oligomers. CRMP‐2 was the major substrate of ROK. p80 CRMP‐1 interacted with the kinase domain of ROKα, resulting in inhibition of the catalytic activity towards other substrates. Over‐expression of p80 CRMP‐1 and CRMP‐2 together counteracted the effects of RhoA on neurite retraction, an effect enhanced by mutation of the ROK phosphorylation site in CRMP‐2. p80 CRMP‐1 and CRMP‐2 may be modulators of RhoA‐dependent signaling, through interaction with and regulation of ROKα.
A high‐affinity competitive inhibitor of type A botulinum neurotoxin protease activity
Authors: Schmidt James J. , Stafford Robert G.
Published: December 2002

The peptide N‐acetyl‐CRATKML‐amide is an effective inhibitor of type A botulinum neurotoxin (BoNT A) protease activity [Schmidt et al., FEBS Lett. 435 (1998) 61–64]. To improve inhibitor binding, the peptide was modified by replacing cysteine with other sulfhydryl‐containing compounds. Ten peptides were synthesized. One peptide adapted the structure of captopril to the binding requirements of BoNT A, but it was a weak inhibitor, suggesting that angiotensin‐converting enzyme is not a good model for BoNT A inhibitor development. However, replacing cysteine with 2‐mercapto‐3‐phenylpropionyl yielded a peptide with K
i of 330 nM, the best inhibitor of BoNT A protease activity reported to date. Additional modifications of the inhibitor revealed structural elements important for binding and supported our earlier findings that, with the exception of P1′ arginine, subsites on BoNT A are not highly specific for particular amino acid side chains.