bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparison of the morphological effects of acidic and basic fibroblast growth factors on rat astroblasts in culture
Authors: Perraud F. , Labourdette G. , Miehe M. , Loret C. , Sensenbrenner M. 
Published: January 2005

AbstractThe effect of acidic and basic fibroblast growth factors (aFGF and bFGF) on the morphology of cultured rat astroblasts and on the expression of glial fibrillary acidic protein (GFAP) were compared. The addition of either aFGF or bFGF affected the morphology of the flat, irregular, polygonal‐shaped astroblasts, which formed processes and acquire a fibrous appearance. Appreciable different morphological aspects were observed between aFGF‐ and bFGF‐induced cells, essentially between 11 and 14 days in culture. In the presence of bFGF the astroglial cells were more fibrous with a more compact perikaryon as compared to aFGF treated cells.At the ultrastructural level abundant intermediate filaments were observed in astroglial cells as an effect of aFGF and rare filaments but numerous microtubules were seen in bFGF‐treated cells.The immunoreactivity for GFAP increased with time in culture and was much stronger in aFGF‐treated cells compared to bFGF‐treated cells at day 14. An intense positive staining was observed in the somata of the astroglial cells and their processes in the presence of aFGF, while essentially the processes were stained in the presence of bFGF. After 21 days in culture GFAP immunoreaction was also found in the perikarya of cells treated with bFGF.These results show that rat astroglial cells respond somewhat differently to aFGF and bFGF.
Localization of ingensin in rat central nervous system and skeletal muscle
Authors: Kamakura Keiko , Ishiura S. , Nonaka I. , Sugita H. 
Published: January 2005

AbstractA high molecular weight, fatty acid‐ and SDS‐sensitive protease named ingensin was purified from rat brain in this study. The enzyme purified from rat brain has the same biochemical properties as those purified from other tissues, e.g., porcine skeletal muscle, human placenta, and rat liver in our laboratory, and rat skeletal muscle and bovine pituitary gland in other laboratories, independently. Immunoblot bands were detected in the same positions as those in the case of ingensin from rat liver.In addition, its topographical distribution was studied in rat brain and muscle by means of the immunohistochemical method. The cytoplasm of motor neurons of the spinal cord, pyramidal cells, and granular cells were stained. Axons were stained. The cytoplasm of muscle was also stained, especially that of type 2 fibers.
Spread of Trypanosoma brucei to the nervous system: Early attack on circumventricular organs and sensory ganglia
Authors: Schultzberg M. , Ambatsis M. , Samuelsson E.‐B. , Kristensson K. , van Meirvenne N. 
Published: January 2005

AbstractThe distribution of Trypanosoma brucei brucei in the nervous system of experimentally infected Sprague‐Dawley rats and BALB/c and deer mice was examined with immunohistochemical techniques. The trypanosomes showed an early invasion in areas lacking a so‐called blood‐brain or blood‐nerve barrier, i.e., in sensory ganglia and circumventricular organs including the area postrema, pineal gland, and median eminence. This distribution of trypanosomes may relate to the origin of cardinal symptoms of the disease, e.g., sensory disturbances, nausea, disturbed circadian rhythm, and neuroendocrinological dysfunctions. Trypanosome infections in rodents may provide a model for studies of how an infectious agent or factors released by the immune response may relatively selectively interfere with these functionally defined regions of the nervous system.
Growth and differentiation properties of O‐2A Progenitors purified from rat cerebral hemispheres
Authors: Behar T. , McMorris F. A. , Novotný E. A. , Barker J. L. , Dubois‐Dalcq M. 
Published: January 2005

AbstractWe have used the monoclonal antibody A2B5 (which binds to subclasses of surface gangliosides) to select glial precursor cells from postnatal rat brain and compare their properties in culture with those of the bipotential O‐2A progenitor cells of newborn optic nerve. Two methods, fluorescence‐activated cell sorting (FACS) and differential adhesion, resulted in >90% enrichment in A2B5‐positive bipolar cells and multipolar cells with short processes. These cells expressed vimentin and reacted with yet another antibody (NSP4), which binds to O‐2A progenitor cells of optic nerve. The 2–10% of the remaining cells consisted of type 1 astrocytes and/or microglial cells. When maintained in defined medium for 3 days, 28‐40% of A2B5‐positive cells incorporated thymidine, while most other cells became differentiated into galactocerebroside‐positive oligodendrocytes. In the presence of 10% fetal calf serum for 3 days, over 50% of the cells developed a stellate phenotype and expressed GFAP, characteristic of type 2 astrocytes. This phenotypic plasticity of the A2B5 positive cells was also observed in clones derived from single cells grown on a layer of type 1 astrocytes. Thus, A2B5‐positive cells from cerebrum are O‐2A progenitors that can generate O‐2A lineage cells. The effects of the two growth factors, insulin and platelet derived growth factor (PDGF) (which is synthesized by type 1 astrocytes), were tested on cerebrum O‐2A progenitors. PDGF induced a doubling of the percentage of A2B5‐positive cells incorporating thymidine during a 20‐hr pulse and a large increase (up to 40‐fold) of the progenitor population over 3 days. The largest number of O‐2A lineage cells was obtained when purified progenitors were grown in the presence of PDGF and insulin. Thus, A2B5‐positive glial cells from cerebrum overall behave as the O‐2A progenitors of optic nerve, but they more readily divide than differentiate, as if they were at an earlier stage along the O‐2A lineage pathway.
Ability of developing epithelia to attract neurite outgrowth in culture is not correlated with the appearance of laminin
Authors: Nishi R. 
Published: January 2005

AbstractUsing a new technique for organ explants that facilitates the visualization of developing epithelia, we tested the abilities of salivary gland and lung rudiments to support de novo axonal outgrowth from the embryonic submandibular ganglion. We confirmed that salivary gland epithelia, but not lung epithelia, are able to support axonal outgrowth. This neurite outgrowth is also supported by salivary gland epithelia that have been lightly fixed with paraformaldehyde. When given a choice of both salivary gland and lung epithelia as a substrate for axonal outgrowth, the submandibular ganglion neurons showed an absolute preference for the salivary gland. Immunohistochemical localization of laminin was performed on whole mounts of developing epithelia after growing neurites were localized with a histochemical stain for esterase. Areas of lung epithelium devoid of any neurite outgrowth contained substantial immunoreactivity for laminin. In addition, Western blot analyses of extracts of embryonic lung and salivary gland indicate that the same amount of laminin or more is present on a per protein basis in the lung as in the salivary gland. An antiserum directed against laminin and a monoclonal antibody that blocks axonal regeneration on basal laminae in vitro (INO) were unable to block the outgrowth of axons over fixed epithelia. This suggests that molecules other than laminin are responsible for the preferential growth of axons over the salivary gland epithelia.
Developmental and regional regulation of rab3: A new brain specific “ras‐like” gene
Authors: Ayala J. , Olofsson B. , Tavitian A. , Prochiantz A. 
Published: January 2005

AbstractRecently, the expression of rab3, a new ras‐like gene, has been shown to be restricted to brain tissues (Olofsson et al., 1988). This finding has prompted us to study the expression of rab3 in different brain regions of the developing mouse. The two transcripts corresponding to rab3 (1.8 and 1.3 kb) were first detected in the brains of E13 mouse embryos and were not randomly distributed. Highest levels were found in the mesencephalon, followed by the cortex, striatum, cerebellum, and brain stem in that order. In vitro, the expression of the 1.8‐kb transcript was neuron specific, whereas the small transcript was present in neurons and astrocytes. This is the first report showing developmental and regional regulation of a nervous system‐restricted ras‐like gene. Based on the homologies found between the rab genes and YPT1 or sec‐4, we suggest that the physiological role of rab3 might be related to the stabilization of the neuronal cytoskeleton or to post‐Golgi vesicle transport and fusion.
Acute effects of lithium on catecholamines, serotonin, and their major metabolites in discrete brain regions
Authors: Gottberg E. , Grondin L. , Reader T. A. 
Published: January 2005

AbstractThe acute effects of lithium on the central catecholamine and serotonin systems were investigated in welldefined cortical areas in the rat: the anterior cingulate cortex (CIN), the piriform‐entorhinal region (PiEn), and the primary visual area (VIS) as well as in the hippocampus (HIP), the neostriatum (CPU; caudateputamen), and the olfactory bulbs (OBs). In these microdissected regions, the catecholamines noradrenaline (NA) and dopamine (DA), the indoleamine 5hydroxytryptamine (5‐HT; serotonin), as well as some of their major metabolites (3‐methoxy‐4‐hydroxyphenylglycol; 3,4‐dihydroxyphenylacetic acid; homovanillic acid; 3‐methoxytyramine; 5‐hydroxy‐ltryptophan; and 5‐hydroxyindole‐3‐acetic acid) were assayed by using high‐performance liquid chromatography (HPLC) with electrochemical detection. One hour after the administration of lithium chloride (2 and 10 mEq/kg; i.p.) the endogenous NA levels increased in the CIN and PiEn cortices, in the HIP, and in the CPU. The DA contents remained unchanged in the CPU, HIP, OB, and VIS cortex but were increased in the CIN and PiEn regions. These increases in cortical DA levels were accompanied by reductions in HVA and DOPAC. The levels of HVA and DOPAC but not 3‐MT were also reduced in the CPU, in spite of a normal DA content. The discrepancies between changes of DA and the levels of its metabolites indicate changes in the turnover rates as well as an action of lithium on DA synthesis and/or storage in the nigrostriatal and mesocortical systems. The 5‐HT contents were also increased by lithium throughout all regions, except for the OB. The 5‐HTP and 5‐HIAA levels remained constant except for slight decreases of 5‐HIAA in the CIN and VIS cortices.
Glucose transporter localization in brain using light and electron immunocytochemistry
Authors: Gerhart D. Z. , Levasseur R. J. , Broderius M. A. , Drewes L. R. 
Published: January 2005

AbstractA polyclonal antibody to a synthetic 13 amino acidpeptide found at the carboxyl‐terminal end of the glucose transporter protein was raised in rabbit and used in light and electron immunocytochemical studies of human and canine brain. This antibody identified a broad band of polypeptide of average Mr 55,000 on immunoblots (immunogold‐silver stains) of electrophoresed membrane proteins from human red blood cells. A similar polypeptide band (Mr 45,000–60,000) was identified on immunoblots of microvessel membrane proteins isolated from canine cerebrum, suggesting that this antibody is a useful tool for studying the distribution and abundance of the glucose transporter protein in mammalian nervous tissue. Peroxidase antiperoxidase stains of cerebrum using this antibody demonstrated that transporters are abundant in the intima pia, in the endothelium of blood vessels in the subarachnoid space, and in the endothelium of arterioles, venules, and capillaries of gray and white matter. In cerebellum, reaction product was localized in the vessels of the subarachnoid space and in microvessels of the molecular layer, the granular layer, and the white matter. However, transporters were not found in the intima pia of cerebellum. In medulla oblongata, transporters were found in the intima pia, the endothelium of some subarachnoid vessels, and the microvessels of gray and white matter. In pituitary, microvessels in adenohypophysis contained no reaction product, but the antigen was detected in some microvessels in neurohypophysis. Electron microscopy of cerebral cortex using a protein A‐gold technique demonstrated that glucose transporters are equally abundant on the luminal and abluminal membranes of microvessel endothelial cells. When thin sections were stained by floating grids on top of antibody and reagents (single‐sided staining), 84% of the gold particles counted were associated with endothelial plasma membranes and tight junctions, 9% were associated with endothelial cytoplasm, vesicles, or plasmalemma invaginations, and 6% were associated with nonendothelial structures (basement membrane, pericyte, smooth muscle cell, or vessel lumen).
K‐252a inhibits the increase in c‐fos transcription and the increase in intracellular calcium produced by nerve growth factor in PC12 cells
Authors: Lazarovici P. , Levi B.‐Z. , Lelkes P. I. , Koizumi S. , Fujita K. , Matsuda Y. , Ozato K. , Guroff G. 
Published: January 2005

AbstractK‐252a, a kinase inhibitor isolated from the culture broth of Nocardiopsis sp., selectively inhibits, in a dose‐ and time‐dependent fashion, the increased transcription of the protooncogene c‐fos induced by nerve growth factor in PC12 cells. Induction of c‐fos by epidermal growth factor, A23187, dBcAMP, or TPA in the same cells is not affected. Pretreatment with K‐252a for 30 min results in a complete inhibition of the nerve growth factor‐induced increase in intracellular calclum. Increases in intracellular calcium induced by carbachol or by high K+ are not altered. K‐252a derivatives selective for the inhibition of various known kinases were used to inhibit the nerve growth factor‐dependent induction of c‐fos mRNA, the nerve growth factor‐dependent increase in intracellular calcium levels, and the nerve growth factor‐dependent outgrowth of neurites. K‐252a is the most effective inhibitor of all three of these actions of nerve growth factor. The possible mechanisms by which K‐252a acts on PC12 cells are considered in the light of the characteristics of the inhibitions seen here.
Human T lymphocyte response to myelin basic protein: Selection of T lymphocyte lines from mbp‐responsive donors
Authors: Vandenbark A. A. , Chou Y. K. , Bourdette D. , Whitham R. , Chilgren J. , Chou C.‐H. J. , Konat G. , Hashim G. , Vainiene M. , Offner H. 
Published: January 2005

AbstractThe goal of this study was to delineate the importance of blood T lymphocyte responses to several myelin basic protein (MBP) preparations in the ultimate selection of MBP‐specific T lymphocyte lines. Proliferation responses to human myelin basic protein (MBP) were assessed in blood samples from 27 multiple sclerosis (MS) patients, 20 patients with other neurologic diseases (OND), and 26 normal subjects, using five MBP preparations with different histories and electrophoretic characteristics to enhance the spectrum of epitopes represented. Substantial variations were observed in the ability of different MBP preparations to induce blood T cell proliferation in a given donor. However, four out of five of the MBPs induced modest but significant proliferation in the MS study population relative to normal individuals, with intermediate responses occurring in OND patients. Positive responses occurred more frequently in MS patients (78%) than in normal donors (31%), and were an important prerequisite for the successful selection of MBP‐specific T cell lines.
Effect of hepes on the taurine uptake by cultured glial cells
Authors: Lleu P. L. , Rebel G. 
Published: January 2005

AbstractHEPES inihibited the taurine uptake in glial cells. A different kind of inhibition was observed when HEPES was present in the culture medium or in the incubation medium used for the taurine‐uptake measurement. As an example of a possible interference of HEPES in pharmacological experiments, we have studied the effect of this buffer on the modulation of taurine uptake by β agonists or ionic concentration.
Aspartate neurotoxicity on cultured cortical neurons
Authors: Choi D. W. , Viseskul V. , Amirthanayagam M. , Monyer H. 
Published: January 2005

AbstractL‐aspartate neurotoxicity was quantitatively characterized in murine cortical cell cultures. Five‐minute exposure to 30 μM–3 mM L‐aspartate resulted in concentration‐dependent (ED50 about 190 μM) neuronal destruction over the next 10 hr; glia were not injured. D‐aspartate and L‐aspartate were roughly equipotent neurotoxins. Ion substitution experiments suggested that L‐aspartate neurotoxicity is comprised of both acute, sodium‐dependent “excitotoxicity” and delayed, calcium‐dependent degeneration, with the latter predominant under conditions of brief exposure. Aspartate neurotoxicity could be attenuated by D‐2‐amino‐5‐phosphonovalerate (D‐APV), dextrorphan, ketamine, and kynurenate, but not by L‐glutamate diethyl ester or gamma‐D‐glutamyl‐aminomethyl sulfonate, consistent with principal involvement of N‐methyl‐D‐aspartate receptors. DAPV and dextrorphan produced different effects on the aspartate concentration–toxicity relation; the former drug was consistent with a competitive and the latter with a noncompetitive mechanism of antagonism.
Tis gene expression in cultured rat astrocytes: Multiple pathways of induction by mitogens
Authors: Arenander A. T. , Lim R. W. , Varnum B. C. , Cole R. , de Vellis J. , Herschman H. R. 
Published: January 2005

AbstractAccumulation of TIS1 and TIS11 (Lim et al.: Oncogene 1:263–270, 1987) mRNAs in secondary cultures of rat neocortical astrocytes was much greater in response to tetradecanoyl phorbol acetate (TPA) than in response to either epidermal growth factor (EGF) or fibroblast growth factor (FGF). In contrast, EGF, FGF, and TPA were equally effective in inducing accumulation of TIS8 and TIS28/c‐fos mRNAs. These data suggested that TPA and the polypeptide mitogens might induce TIS gene expression by distinct pathways. When maximally inducing concentrations of EGF and FGF were co‐administered to astrocyte cultures, TIS mRNA accumulations were no greater than those observed for the individual growth factors, suggesting that EGF and FGF saturate a common, limiting step in their induction pathways. In contrast, when either EGF or FGF was presented to astrocytes in combination with maximally inducing levels of TPA, the resulting levels of accumulation of TIS mRNAs were at least as great as the sum of the levels induced by the individual mitogens. Stimulation of [3H]‐thymidine incorporation demonstrated an identical pattern of interaction; EGF and FGF co‐administration was no more effective than either polypeptide mitogen alone, but, when presented to astrocyte cultures along with maximally inducing concentrations of TPA, either EGF or FGF was able to increase incorporation of [3H]‐thymidine.Superinduction of all the TIS genes occurred if cycloheximide (CHX) was present during TPA exposure. Once again, two distinet classes of responses of the various TIS genes occurred; superinduction of TIS1, TIS7, TIS11, and TIS28/c‐fos mRNA accumulation ranged from 10‐ to 20‐fold, while CHX superinduction of TIS8 and TIS10 was far more modest, ranging from 2‐ to 3‐fold. Differential superinduction of TIS gene expression also occurred when astrocytes were challenged with TPA in the presence of the peripherally active benzodiazepine (BZD) Ro5‐4864, ranging from a high of fivefold (TIS28/c‐fos) to no superinduction effect (TIS8). The temporal patterns and relative efficacies of BZD and CHX superinduction of the various TIS genes were quite distinct.Induction of TIS gene accumulation occurs in response to a wide variety of ligands by several independent pathways and can be secondarily modulated by a number of additional factors. The differential expression of this set of transient primary‐response gene products may play a major role in integrating information that impinges on cells and in directing their physiological responses.
Basic fibroblast growth factor released from synthetic guidance channels facilitates peripheral nerve regeneration across long nerve gaps
Authors: Aebischer P. , Salessiotis A. N. , Winn S. R. 
Published: January 2005

AbstractBasic fibroblast growth factor (b‐FGF) has been shown to enhance the in vitro survival and neurite extension of various types of neurons including dorsal root ganglia (DRG) cells. Alpha‐1 glycoprotein (α1‐GP), an acute phase reactant, has been reported to enhance the in vitro neuritic extensions of chick DRG cells. In the present study, we investigated the ability of synthetic nerve guidance channels, which release sustained controlled amounts of b‐FGF and/or α1‐GP, to support the regeneration of a transected peripheral nerve over a 15 mm long gap, a distance that does not permit regeneration in conventional polymeric tubes. Tubes releasing bovine serum albumin (BSA), cytochrome C, BSA and b‐FGF, BSA and denatured b‐FGF, BSA and α1‐GP, or BSA, b‐FGF, and α‐1GP were fabricated by a dip‐molding technique. In vitro kinetic studies of protein release from these channels showed an initial burst during the 1st day, followed by a linear release for at least 2 weeks thereafter. In vitro studies indicated that the b‐FGF released from the polymer was biologically active as assessed by the ability of channels releasing b‐FGF to induce neurite extensions in PC12 cells. For in vivo studies, the various types of tubes were used as nerve guidance channels for the repair of a 15 mm nerve gap in the sciatic nerve of rats. Four weeks postimplantation, only the tubes releasing b‐FGF or b‐FGF and α1‐GP displayed regenerated cables bridging both nerve stumps, which contained nerve fascleles with myelinated and unmyelinated axons. We conclude that b‐FGF enhances peripheral nerve regeneration and that polymeric tubes releasing macromolecules provide a tool for the study of nerve regeneration.