bluuebunny/crossref_metadata_2025_split huggingface dataset:
Selective specification of CNS stem cells into oligodendroglial or neuronal cell lineage: Cell culture and transplant studies
Authors: Espinosa‐Jeffrey Araceli , Becker‐Catania Sara G. , Zhao Paul M. , Cole Ruth , Edmond John , de Vellis Jean 
Published: October 2002

AbstractNeural stem cells (NSCs) were isolated from embryonic day 16 Sprague–Dawley rats and cultured in a novel serum‐free stem cell medium that selected for the growth of NSCs and against the growth of GFAP+ cells (astrocytes). NSCs maintained in culture for extended periods of time retained immunoreactivity for both nestin and PSA‐NCAM, two markers characteristic of the stem cell phenotype. Moreover, using an oligodendrocyte (OL) specification medium, NSCs differentiated into OL as evidenced by their morphology and expression of multiple oligodendrocyte/myelin‐specific markers. In addition, NSCs are capable of acquiring a neuronal phenotype as evidenced by expressing neuronal markers, such as neurofilament (NF) and NeuN when cultured in a defined medium for neurons indicating that these cells are also a good source of neuroblasts, which could be used to replace neuronal populations in the brain. We also showed successful propagation and differentiation of NSCs into OL after cryostorage, allowing for the later use of stored NSCs. The long‐term goal of culturing NSCs and committed oligodendrocyte progenitors (OLP) is to obtain homogeneous populations for transplantation with the goal of remyelinating the myelin‐deficient CNS. Our preliminary experiments carried out on normal and myelin deficient rats demonstrate that these cells survive and migrate extensively in both types of hosts. NSCs grafted as such, as well as cells derived from NSCs exposed to selective specification before grafting, are able to differentiate within the host brain. As expected, NSCs are capable of giving rise to astrocytes in a medium favoring this phenotype. © 2002 Wiley‐Liss, Inc.
Developmental regulation of the effects of fibroblast growth factor‐2 and 1‐octanol on neuronogenesis: Implications for a hypothesis relating to mitogen–antimitogen opposition
Authors: Goto T. , Takahashi T. , Miyama S. , Nowakowski R.S. , Bhide P.G. , Caviness V.S. 
Published: October 2002

AbstractNeocortical neurons arise from a pseudostratified ventricular epithelium (PVE) that lies within the ventricular zone (VZ) at the margins of the embryonic cerebral ventricles. We examined the effects of fibroblast growth factor‐2 (FGF‐2) and 1‐octanol on cell output behavior of the PVE in explants of the embryonic mouse cerebral wall. FGF‐2 is mitogenic and 1‐octanol antimitogenic in the PVE. Whereas all postmitotic cells migrate out of the VZ in vivo, in the explants some postmitotic cells remain within the VZ. We refer to these cells as the indeterminate or I fraction, because they neither exit from the VZ nor reenter S phase as part of the proliferative (P) fraction. They are considered to be either in an extremely prolonged G1 phase, unable to pass the G1/S transition, or in the G0 state. The I fate choice is modulated by both FGF‐2 and 1‐octanol. FGF‐2 decreased the I fraction and increased the P fraction. In contrast, 1‐octanol increased the I fraction and nearly eliminated the P fraction. The effects of FGF‐2 and 1‐octanol were developmentally regulated, in that they were observed in the developmentally advanced lateral region of the cerebral wall but not in the medial region. © 2002 Wiley‐Liss, Inc.
Nestin enhancer requirements for expression in normal and injured adult CNS
Authors: Johansson Clas B. , Lothian Carina , Molin Magnus , Okano Hideyuki , Lendahl Urban 
Published: October 2002

AbstractThe nestin gene is expressed in many CNS stem/progenitor cells, both in the embryo and the adult, and nestin is used commonly as a marker for these cells. In this report we analyze nestin enhancer requirements in the adult CNS, using transgenic mice carrying reporter genes linked to three different nestin enhancer constructs: the genomic rat nestin gene and 5 kb of upstream nestin sequence (NesPlacZ/3), 636 bp of the rat nestin second intron (E/nestin:EGFP), and a corresponding 714 bp region from the human second intron (Nes714tk/lacZ). NesPlacZ/3 and E/nestin:EGFP mice showed reporter gene expression in stem cell‐containing regions of brain and spinal cord during normal conditions. NesPlacZ/3 and E/nestin:EGFP mice showed increased expression in spinal cord after injury and NesPlacZ/3 mice displayed elevated expression in the periventricular area of the brain after injury, which was not the case for the E/nestin:EGFP mice. In contrast, no expression in adult CNS in vivo was seen in the Nes714tk/lacZ mice carrying the human enhancer, neither during normal conditions nor after injury. The Nes714 tk/lacZ mice, however, expressed the reporter gene in reactive astrocytes and CNS stem cells cultured ex vivo. Collectively, this suggests a species difference for the nestin enhancer function in adult CNS and that elements outside the second intron enhancer are required for the full injury response in vivo. © 2002 Wiley‐Liss, Inc.
Neurospheres modified to produce glial cell line‐derived neurotrophic factor increase the survival of transplanted dopamine neurons
Authors: Ostenfeld Thor , Tai Yu‐Tzu , Martin Peter , Déglon Nicole , Aebischer Patrick , Svendsen Clive N. 
Published: October 2002

AbstractGlial cell line‐derived neurotrophic factor (GDNF) has been shown to increase the survival of dopamine neurons in a variety of in vitro and in vivo model systems. Therefore, it constitutes an important therapeutic protein with the potential to ameliorate dopamine neuronal degeneration in Parkinson's disease or to support dopamine neuronal replacement strategies. However, biophysical and practical considerations present obstacles for the direct delivery of the GDNF protein to CNS neurons. Here we show that rodent neural precursor cells isolated and expanded in culture as neurospheres (NS) can be genetically modified to express green fluorescent protein (GFP) or to release GDNF using lentiviral constructs. GDNF‐NS increased the fibre outgrowth of primary embryonic dopamine neurons in cocultures, showing that the protein was released in biologically significant quantities. Furthermore, after transplantation into the 6‐hydroxydopamine‐lesioned rat striatum, GDNF‐NS significantly increased the survival of cografted primary dopamine neurons. However, this was not reflected in behavioural recovery in these animals. We found that, by 6 weeks, few cells expressed GDNF or GFP, suggesting either that transgene expression was down‐regulated over time or that the cells died. This may explain the initial effects on dopamine neuronal survival within the graft but the lack of long‐term effect on subsequent fibre outgrowth and behaviour. Providing sustained levels of neural precursor‐mediated transgene expression can be achieved following transplantation in the future; this approach may prove beneficial as an alternative therapeutic strategy in the cell‐based management of Parkinson's disease. © 2002 Wiley‐Liss, Inc.
Amphiregulin is a mitogen for adult neural stem cells
Authors: Falk Anna , Frisén Jonas 
Published: October 2002

AbstractNeurons are continuously generated from stem cells in the hippocampus and along the lateral ventricles in the adult brain. Neural stem cells can be propagated in vitro in the presence of epidermal growth factor (EGF) or fibroblast growth factor‐2. We report here that amphiregulin, a growth factor related to EGF, is a mitogen for adult mouse neural stem cells in vitro and displays potency similar to that of EGF. Neural stem cell cultures can be initiated and the cells propagated as efficiently in the presence of amphiregulin only as with EGF. Furthermore, we show that amphiregulin is expressed in the choroid plexus of the ventricular system and in the hippocampus in the adult brain, suggesting that amphiregulin may participate in the regulation of neural stem cell proliferation and neurogenesis in the adult brain. © 2002 Wiley‐Liss, Inc.
Engraftment of sorted/expanded human central nervous system stem cells from fetal brain
Authors: Tamaki Stanley , Eckert Karl , He Dongping , Sutton Richard , Doshe Monika , Jain Gitanjali , Tushinski Robert , Reitsma Michael , Harris Brent , Tsukamoto Ann , Gage Fred , Weissman Irving , Uchida Nobuko 
Published: October 2002

AbstractDirect isolation of human central nervous system stem cells (CNS‐SC) based on cell surface markers yields a highly purified stem cell population that can extensively expand in vitro and exhibit multilineage differentiation potential both in vitro and in vivo. The CNS‐SC were isolated from fetal brain tissue using the cell surface markers CD133+, CD34–, CD45–, and CD24–/lo (CD133+ cells). Fluorescence‐activated cell sorted (FACS) CD133+ cells continue to expand exponentially as neurospheres while retaining multipotential differentiation capacity for >10 passages. CD133–, CD34–, and CD45– sorted cells (∼95% of total fetal brain tissue) fail to initiate neurospheres. Neurosphere cells transplanted into neonatal immunodeficient NOD‐SCID mice proliferated, migrated, and differentiated in a site‐specific manner. However, it has been difficult to evaluate human cell engraftment, because many of the available monoclonal antibodies against neural cells (β‐tubulin III and glial fibrillary acidic protein) are not species specific. To trace the progeny of human cells after transplantation, CD133+‐derived neurosphere cells were transduced with lentiviral vectors containing enhanced green fluorescent protein (eGFP) expressed downstream of the phosphoglycerate kinase promoter. After transduction, GFP+ cells were enriched by FACS, expanded, and transplanted into the lateral ventricular space of neonatal immunodeficient NOD‐SCID brain. The progeny of transplanted cells were detected by either GFP fluorescence or antibody against GFP. GFP+ cells were present in the subventricular zone‐rostral migrating stream, olfactory bulb, and hippocampus as well as nonneurogenic sites, such as cerebellum, cerebral cortex, and striatum. Antibody against GFP revealed that some of the cells displayed differentiating dendrites and processes with neurons or glia cells. Thus, marking human CNS‐SC with reporter genes introduced by lentiviral vectors is a useful tool with which to characterize migration and differentiation of human cells in this mouse transplantation model. © 2002 Wiley‐Liss, Inc.
Effects of gamma irradiation on physical and chemical properties of chickpeas (Cicer arietinum)
Authors: Graham John A , Panozzo Joe F , Lim Patrick C , Brouwer Jan Bert 
Published: October 2002

AbstractChanges in the physical and chemical properties of chickpeas gamma irradiated with 60Co at doses of 0–50 kGy were investigated. Irradiation between 0 and 20 kGy had no significant effect on the hydration capacity of the chickpeas; however, increasing the dose from 20 to 50 kGy significantly decreased the hydration capacity owing to leaching of soluble compounds from the cotyledon to the water. There was an improvement in cooking quality (defined as degree of softness) with increased irradiation. Gelatinisation properties of the starch (measured with a Rapid Visco‐Analyser) exhibited a deterioration with increasing irradiation dose, while reversed phase HPLC identified a sequential decrease in low‐molecular‐weight protein composition with increasing irradiation dose.© 2002 Society of Chemical Industry
In vitro availability of minerals from oat products
Authors: Skibniewska Krystyna A , Kozirok Witold , Fornal Lucja , Markiewicz Kazimierz 
Published: October 2002

AbstractThe content of macroelements P, Mg and Ca and microelements Mn, Fe, Zn and Cu was determined in 10 commercially sold oat products made by different technological processes (dehulling, instantinising, extrusion, flaking). Phosphorus was the most prevalent of the macroelements (from 240.8 ± 2.2 to 845.5 ± 8.1 mg per 100 g), followed by magnesium (from 73.2 ± 0.7 to 271.9 ± 2.7 mg per 100 g) and calcium (from 30.69 ± 0.01 to 112.7 ± 0.3 mg per 100 g). The Ca/P ratio ranged from 1:5.3 in crushed oat to 1:8.2 in oat flakes. Regarding the microelements, manganese was present at the highest concentrations (from 2.62 ± 0.02 to 8.69 ± 0.01 mg per 100 g). The content of iron was similar and that of zinc not much lower, whereas the amount of copper was considerably smaller (from 0.23 ± 0.002 to 0.59 ± 0.002 mg per 100 g). The highest concentrations of mineral elements were found in instant oat bran flakes and the lowest in extruded oat and corn crisps containing 50% corn grouts. Samples of the products analysed were subjected to in vitro enzymatic digestion, simulating the digestive process occurring in the human alimentary tract. The supernatants thus obtained were analysed for their content of the previously determined mineral components; the percentage of minerals released from the products was calculated. The following sequence of mineral components released was observed: Cu (57.2–95.6%) > P (39.7–60.9%) > Ca (18.2–39.5%) > Mg (16.4–39.8%) > Mn (6.4–24.7%) > Fe (6.5–29%) > Zn (11–17.2%). The Ca/P ratio in the supernatant worsened from 1:8.2 in crushed oat to 1:23.3 in extruded oat and corn crisps. Crushed oat released the highest amounts of mineral elements during enzymatic hydrolysis, with oat grouts coming second. As regards the other products, it is difficult to establish their relative sequence in the release of minerals.© 2002 Society of Chemical Industry
Effect of minimal processing on the textural and structural properties of fresh‐cut pears
Authors: Soliva‐Fortuny Robert C , Grigelmo‐Miguel Nuria , Hernando Isabel , Lluch M Ángeles , Martín‐Belloso Olga 
Published: October 2002

AbstractThe feasibility of minimal processing and modified atmosphere packaging to preserve the original textural quality of fresh‐cut pears was evaluated throughout storage under refrigeration. Fresh‐cut pear firmness could be extended up to several weeks with low‐O2 atmospheres. A packaging atmosphere of 100% N2 combined with the use of plastic bags with an O2 permeability of 15 cm3 m−2 bar−1 day−1 maintained cell structure and partially avoided membrane breakdown and exudate accumulation in intercellular spaces. Under the other conditions studied, pear texture underwent dramatic deterioration, which could be related to complete inundation of the extracellular environment. Firmness decreased linearly throughout the storage period studied, with rate constants ranging from 0.0097 to 0.040 day−1. The consideration of other textural variables also gave valuable information, similar to that provided by firmness data.© 2002 Society of Chemical Industry
Dehydroepiandrosterone as an enhancer of functional recovery following crush injury to rat sciatic nerve
Authors: Gudemez Eftal , Ozer Kagan , Cunningham Brian , Siemionow Krzysztof , Browne Earl , Siemionow Maria 
Published: October 2002

AbstractThis study was designed to investigate the effect of dehydroepiandrosterone (DHEA) on the recovery of the rat sciatic nerve following crush injury. A standard hemostat system was used to create the injury, with a length of 1.5 mm in three groups of 18 animals each. In group I, the crush injury was applied without any treatment. In groups II and III, vehicle (ethylene glycol) and DHEA solutions were injected subepineurally 30 min following the crush injury. Sciatic function index (SFI), toe contracture measurement, gastrocinemius muscle weight, total number of myelinated fibers, fiber diameters, myelin thickness, and axon/fiber cross‐sectional ratio were measured at 3, 6, and 12 weeks. The SFI values in the DHEA group showed a faster return to normal values confirmed at 3 and 6 weeks (P < 0.05). The number of myelinated fibers and fiber diameters at 6 and 12 weeks were significantly higher in the DHEA group (P < 0.05). In this study, the subepineural injection of DHEA following crush injury was found to enhance functional recovery of the rat sciatic nerve. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:234–241 2002
Repeated upper limb salvage in a case of severe traumatic soft‐tissue and brachial artery defect
Authors: Noaman Hassan Hamdy , Shiha Anis Elsayed 
Published: October 2002

AbstractWe present the case of a 9‐year‐old male patient who suffered a gunshot injury to the right arm. The patient arrived in shock, his right arm severely traumatized, with soft‐tissue loss involving the anterior surface and both sides of the right arm. The humerus was exposed. There was brachial artery defect and damage to the lateral fibers of the median nerve. The mangled extremity severity score (MESS) was 8 points. The patient was treated with general resuscitation, blood transfusion, and debridement. A venous graft, 12 cm in length, to bridge the brachial artery defect, and tendon transfer, triceps to the biceps, was performed in one step. Postoperatively, there was a normal radial pulse, normal skin color, normal temperature, and normal movement of the fingers without pain. Unfortunately, the patient then sustained a second trauma to the right arm 3 weeks later, rupturing the graft. This time he lost 1,500 cc of blood. After another blood transfusion, we performed a second reverse saphenous vein graft. The patient stayed at the hospital for 3 weeks. At follow‐up 12 months later, the limb has good function and, except for the presence of a scar and skin graft, is equal in appearance to the left side. © 2002 Wiley‐Liss, Inc. MICROSURGERY 22:249–253 2002
Transient deformation of a poroelastic channel bed
Authors: Hsieh P.C. , Shih W.P. , Huang L.H. 
Published: October 2002

AbstractThe coupled transient response of a poroelastic bed form due to stream flow and non‐linear water waves is investigated numerically. The theory of potential flow is applied to channel flow while Biot's theory of poroelasticity (J. Appl. Phys. 1962; 33(4):1482) is adopted to deal with the deformable porous bed. A boundary‐fitted co‐ordinate system is used to calculate the variation in the bed form. The result of a simple periodic wave form over a soft poroelastic bed agrees well with the analytical solution of Hsieh et al. (J. Eng. Mech., ASCE 2000; 126(10):1064). However, due to the rapidly damping second dilatational wave inside the soft poroelastic bed, the solution for transient bed form near the interface is not easy to compute accurately. In order to overcome this difficulty, a simplified numerical model based on the boundary layer correction concept proposed by Hsieh et al. (2000) is established, which neglects Darcy's terms. The transient deformation of an irregular poroelastic bed that includes a trench and a downward step at the channel bed is simulated successfully. Copyright © 2002 John Wiley & Sons, Ltd.
A theoretical framework for constructing elastic/plastic constitutive models of triaxial tests
Authors: Collins Ian F. , Hilder Tamsyn 
Published: October 2002

AbstractModern ideas of thermomechanics are used to develop families of models describing the elastic/plastic behaviour of cohesionless soils deforming under triaxial conditions. Once the form of the free energy and dissipation potential functions have been specified, the corresponding yield loci, flow rules, isotropic and kinematic hardening rules as well as the elasticity law are deduced in a systematic manner. The families contain the classical linear frictional (Coulomb type) models and the classical critical state models as special cases. The generalized models discussed here include non‐associated flow rules, shear as well as volumetric hardening, anisotropic responses and rotational yield loci. The various parameters needed to describe the models can be interpreted in terms of ratio of the plastic work, which is dissipated, to that which is stored. Non‐associated behaviour is found to occur whenever this division between dissipated and stored work is not equal. Micro‐level interpretations of stored plastic work are discussed. The models automatically satisfy the laws of thermodynamics, and there is no need to invoke any stability postulates. Some classical forms of the peak‐strength/dilatancy relationship are established theoretically. Some representative drained and undrained paths are computed. Copyright © 2002 John Wiley & Sons, Ltd.
Making ‘modernising government initiatives’ work: culture change through Collaborative Inquiry (CI)
Authors: Kakabadse Andrew , Kakabadse Nada 
Published: October 2002

AbstractThe purpose of this article is to share experience of a strategic intervention adopting a collaborative inquiry (CI) process that took place in a formal institutional setting and which evolved into a community‐based inquiry. The article illustrates the CI process through a twelve‐month exploration with a group of senior managers from within the UK Civil Service. The form of CI demonstrated is similar to what has become known as community based research, in that all participants collaboratively pursued the inquiry. A critical element of this collaborative inquiry is that although it started formally and did not spontaneously emerge from the inquiry community, its members shaped the inquiry, conveyed the message, acted as advocates and evaluated the outcomes of the inquiry. The impact of this inquiry is now being positively felt within the UK Civil Service as the members of the inquiry community apply their learning within their own departments. Copyright © 2002 John Wiley & Sons, Ltd.
Building civic infrastructure: implementing community partnership grant programmes in South Africa
Authors: Adams Charles F. , Bell Michael E. , Brown Trevor 
Published: October 2002

AbstractThis article examines recent efforts to establish Community Partnership Grant Programmes (CPG) in six South African communities. CPG programmes provide the financial and organizational infrastructure to support citizen‐initiated neighbourhood projects. We review our efforts to disseminate the CPG programme model in three different environments in South Africa—a large metropolitan area, three smaller municipalities and two tribal villages—and analyse why preliminary implementation results were positive in some communities but not others. Our findings form the basis of a model of CPG programme implementation based on the mode of implementation and the breadth of stakeholder involvement. We use this model to make recommendations to increase the likelihood of implementation success for similar programmes. The article concludes with observations about the applicability of the CPG programme idea as a way to develop civic infrastructure, and on the political lessons learned from our implementation experience in South Africa. Copyright © 2002 John Wiley & Sons, Ltd.