bluuebunny/crossref_metadata_2025_split huggingface dataset:
Myelin‐specific domain on the plasmalemma of oligodendroglia: Differential expression in the rat and hypomyelinating mouse mutants jimpy and quaking
Authors: Gard A. L. , Dutton G. R. 
Published: January 2005

AbstractMonoclonal antibody, 1A9, prepared against bovine white matter, recognizes a proteinaceous, myelin‐specific domain in the CNS that is restricted to the surface of oligodendroglia in primary dissociated cell cultures. The antigen is not detected in the PNS or non‐neural tissues. Antibody binding is abolished by heating, exposure to SDS and delipidation, indicating that a conformationally sensitive epitope is recognized. The antigen is present in tracts of developing white matter in rat cerebellum beginning at 5 days postnatally. In developing cultures of fetal rat brain the period of rapid onset for the phenotypic expression of 1A9 antigen is similar to that of galactocerebroside, corresponding to 2–4 postnatal days of age. The 1A9 antigen is not observed in white matter or cultured oligodendroglia of the hypomyelinating jimpy mutant mouse, but its expression is qualitatively normal in the quaking mutant. The possibility is raised that 1A9 may be the primary target of the jimpy mutation.
Response of rat encephalitogenic T lymphocyte lines to synthetic peptides of myelin basic protein
Authors: Offner H. , Hashim G. , Vandenbark A. A. 
Published: January 2005

AbstractT lymphocyte lines and clones selected from Lewis rats immunized with guinea pig basic protein (GP‐BP) proliferate and acquire the ability to transfer experimental autoimmune encephalomyelitis (EAE) after activation by the 68–88 peptide of GP‐BP in concert with autologous I‐A major histocompatibility antigens. In order to evaluate the amino acid sequence required for activation, encephalitogenic T lymphocytes were stimulated with synthetic peptides representing the 69–89, 69–84, 72–84, and 75–84 sequence of GP‐BP. The three longest peptides, but not the 75–84 peptide, induced encephalitogenic lines and clones to proliferate and to transfer clinical EAE; none of the peptides, however, could activate T cell lines of a different epitope specificity. The 69–89 sequence was the most efficient of the synthetic peptides, inducing optimal stimulation comparable to GP‐BP at 10 μg/ml. The 69–84 and 72–84 sequences induced comparable levels of stimulation at 250 μg/ml, but the 75–84 sequence was not active at any concentration. These results show that the 11 amino acids representing the 72–84 sequence of GP‐BP are sufficient to trigger encephalitogenic T cell activity, and suggest that the 85–89 sequence may stabilize the conformation of the encephalitogenic epitope. The close association observed between proliferation and EAE transfer activities, induced in highly purified T cell populations using synthetic peptides, suggests that these two functional properties of T cells result from a common activation pathway involving a single T cell receptor specificity.
Maturation of a large neurofilament protein (NF 150K) in rat postnatal development
Authors: Dahl D. 
Published: January 2005

AbstractThe mammalian neurofilament is made of three neu‐ron‐specific proteins with approximate molecular weights of 70 kilodaltons (kDa) (NF 70K), 150 kDa (NF 15OK), and 200 kDa (NF 200K) by SDS‐PAGE. As previously reported in the rat by Strocchi et al (J Neurochem 39:1132–1141,1982) and Nixon et al (J Cell Biol) 94:150–58, 19821, NF 150K comprises three molecular weight variants with the same isoelectric point. A fourth lower molecular weight and slightly less acidic variant was identified by monoclonal and polyclonal antibodies reacting with the a‐helical middle domain of NF 150K. With few exceptions, this lower molecular weight variant did not stain with monoclonal antibodies reacting with the peripheral carboxyterminal domain. Staining with these antibodies was abolished or markedly reduced following neurofilament dephosphorylation. The distribution of the NF 150K variants varied in different regions of the nervous system. The higher molecular weight variant (component a) was less prominent in brain compared to spinal cord, optic nerve, and sciatic nerve. Further‐more, the lower molecular weight variant (component d) was not identified in optic nerve and sciatic nerve. All four variants were identified in brain and spinal cord extracts of newborn rats with monoclonal and polyclonal antibodies reacting with the a‐helical middle domain of NF 150K. As a general rule (see Results for exceptions) monoclonal antibodies reacting with the carboxy‐terminal region of NF 150K did not stain the variants in newborn rat brain extracts until day 10 when immunoreactivity of component a first appeared. The adult pattern was first observed on postnatal day 15. With the same antibodies component a was already stained at birth in spinal cord extracts while the adult pattern first appeared on day 10. The delayed appearance of immunoreactivity of the NF 150K variants in development suggests the occurrence of post‐translational modifications probably related to axonal maturation.
Gangliosides fail to enhance behavioral recovery after bilateral ablation of the visual cortex
Authors: Butler W. M. , Griesbach E. , Labbe R. , Stein D. G. 
Published: January 2005

AbstractPostsurgical injections of GM1 gangliosides (30 mg/kg IP) reduced neither behavioral deficits in rats following bilateral ablation of the visual cortex nor the extent of retrograde degeneration of neurons in the dorsolateral geniculate nucleus that typically accompanies large lesions of the visual cortex. Our findings are in contrast to previous research, in which ganglioside treatments have been shown to enhance the rate of functional recovery after lesions in other parts of the central nervous system. The negative findings in the present experiment may be due to the disruption of normal circadian rhythms caused by occipital cortex injury.
The polyclonal antibody responses of lewis rats to the synthetic encephalitogenic neuropeptide S55S (residues 72–84 of guinea pig myelin basic protein) and its analogs
Authors: Day E. D. , Hashim G. A. , Ireland D. J. 
Published: January 2005

AbstractImmunochemical analysis of polyclonal antisera from Lewis rats immunized with peptide analogs and sub‐peptides of residues 72–84 of guinea pig myelin basic protein (MBP) indicated that there were four main epitopic specificities involved: one represented by residues 76–80, one by residues 72–74, one by 81–84‐Gly, and one involving 74–76 in a heteroclitic way even when the immunogen contained a tetraleucine spacer between residues 74 and 75. The affinities were all relatively low, ranging from 3 × 104M−1 to 7.2 × 106M−1, ad each affinity population was very restricted with respect to heterogeneity. The result were commensurate with out hypothesis that autoimmune responses to homologous encephalitogenic neuropeptide determinants reflect an evolutionarily imposed degeneration of the overall response, and were also i agreement with our hypothesis that the affinities of autoantibodies against epitopes in the molecular neighbourhood of an encephalitogen would be necessarily low. I t was also found that peptide 69–81‐Gly(S67) in solution would not interact in liquid phase radioimmunoassays with any of the above antibody populations, thus indicating that its preferred conformation did not allow the expression of autoreactive epitopes. There was no evidence that S67 in solution, even in the presence of S53, would express any epitopes reactive with autoantibodies. How this finding for a B cell product correlates with T cell‐mediated immunologic responses is not totally understood, but it will be recalled that S67 by itself does not induce T cell‐mediated experimental allergic encephalomyelitis (EAE), that S53 (residues 75–84‐Gly) induces only clinical symptoms of EAE without attendant pathological disease, but that the two together induce classical EAE. Thus, it is hypothesized that residues 76–80 (Gln‐Arg‐Ser‐Gln), modulated by Asn‐84, form the B cell determinant essential for subsequent activation of T cell responses to 72–77 to produce the full expression of EAE disease.
Asymmetrical involvement of the cerebral neocortex on the response to an immunopotentiator, sodium diethyldithiocarbamate
Authors: Renoux G. , Bizière K. 
Published: January 2005

AbstractWe have previously shown that the neocortex in mice has a lateralized influence on the immune system. A partial left or bilateral neocortical lesion selectively decreases spleen T‐cell numbers and function, natural killer and (NK) activity, but a right neocortical lesion do not affect NK activity, and increases T‐cell numbers and T‐cell‐mediated events. Here we report that the immunopotentiating activity of sodium diethyldi‐thiocarbamate (Imuthiol®), a compound that selectively increases T‐cell numbers and activities, is dependent on an intact neocortex. The effects of Imuthiol were examined in female C3H/HeJ mice 10 seeks after partial neocortical lesions. In animals with right or bilateral neocortical lesions, Imuthiol failed to increase the percentage of spleen T cells, did not influence the expression of class I MHC antigen on these cells, no longer induced the release in serum of specific T‐cell‐inducing factors, and failed to enhance T‐cell numbers and activities in a fashion that was comparable to that observed in unlesioned controls, but did not enhance NK activity. It is concluded that Imuthiol may affect immune responsiveness by acting directly on the neocortex and/or by interacting at subcortical levels with signals emitted by the neocortex. Moreover, this study reveals a major hemispheric asymmetry in the response to a drug.
Carrier‐mediated transport of vasorpressin across the blood‐brain barrier of the mouse
Authors: Banks W. A. , Kastin A. J. , Horvath A. , Michals E. A. 
Published: January 2005

AbstractA brain to blood carrier‐mediated transport system for agrinine vasopressin (AVP) was investigated in mice after intraventricular injection of iodinated AVP and varying amounts of unlabeled material or candidate inhibitors. Residual activity in the brain detected after decaptiation was used as the main determinant ot transport activity. The half‐time disappearance of iodinated AVP from the brain was 12.4 min, the Vmax was 1.41 nmol/g min, and the apparent Km was 28.7 nmol/g. A 30‐nmol dose of AVP, mestocin, arginine vasotocin, pressionoic, amide, pressinoic acid, tocinoic acid, and lysine vasotocin, but not oxytocin, lysine vasopressin, AVP free acid, tocinoic amide, Tyr‐MIF‐1, or cyclo Leu‐Gly, significantly (P<0.05) inhibited the transport of iodinated AVP out of the brain. The 30 nmol dose of AVP had no effect on the tranport of iodide or iodotyrosine out of the brain. High‐preformance liquid chromatography showed that 59.2% of the radioactivity found in the blood 2 min after an i.c.v. injection of labeld AVP eluted at same postiton as labeled AVP compared with 68.8% of radioactivity eluting at that postition after material was infused i.v. for 2 min. This indicates that intact peptide is transported across the blood‐brain barrier and that most of the degradation of AVP occurs during circulation in the blood. Calculations based on the appearance of radioactivity in the periphery showed that 56.2% of the material injected centrally would have been transported into the periphery by 10 min. This appearance of material in the periphery was inhibited by the simulataneous injection of an excess of unlabeled peptide. Water loading significantly decreased the brain to blood transport rate of AVP by 40%. It is concluded that a saturable system exists for brain to blood transport of AVP and some structurally similar peptides.
Dopamine and noradrenaline content in fish retina: Modulation by serotonin
Authors: Jaffé E. H. , Urbina M. , Ayala C. , Drujan Y. , Drujan B. D. 
Published: January 2005

AbstractThe presence of noradrenaline (NA) and the possible interaction of serotonin (5‐HT) with dopaminergic and noradrenergic neuronal elements was studied in the retina of the teleost Eugerres plumieri. By Means of a histofluorescent technique, paired amacrine cells can be visualized after intravitreal injection of NA or 5,6‐dihydroxytriptamine, suggesting their probable catecholaminergic and indoleaminergic nature. With a high‐performance liquid chromatographic (HPLC) method and after pargyline treatment of the animal, 6.86 ng/mg protein ofdopamine (DA) was detected, while NA content was 0.50 ng/mg protein. The NA levels of the retina increased, whereas the DA levels decreased in a significant manner after in vivo treatment with 5‐HT. 5‐methoxy‐N, N‐demethyltryptamine, a 5‐HT agonist, was able to mimic this effect partially, while the agonists tryptamine and quipazine did not affect the levels of DA and NA. The antagonissts methysergide, metergoline, and cyproheptadine significantly blocked the 5‐HT‐induced NA increase, whereas only the first two antagonists were effective in inhibiting the5‐HT‐induced DA decrease. The 5‐HT modulation of NA and DA is apparently receptor mediated and is not due to a hetero‐exchange, since mipramine was not able to block the 5‐HT effect.These findings support the suggsted interaction between serotoninergic and dopaminergic cells [Negishi et al: J Neurosci Res 5:621–635, 1980; Neurosci Lett 25:1‐5, 1981]. Furthermore, they demonstrate the possible modulation which 5‐HT exerts on the endogenous livels of NA.
Heterogeneity of opioid receptor binding in brain slices
Authors: Barchfeld‐Rothschild C. C. , Medzihradsky F. 
Published: January 2005

AbstractA methodological approach was established for the study of ligand binding to multiple opioid receptors in slices from rat brain striatum. Specific binding of radiolabeled opiates was resolved from total binding with enantiomers or excess unlabeled ligand. Equilibrium binding of triated etorphine, dihydromorphine, and ethylketocyclazocine, and competitive displacement of [3H]dihydromorphine by the unlabeled opiates were used to assess both high and low affinity receptor sites. The high‐affenity binding components of the radiolabeled opiates were characterized by linear Scatchard plots, Kd values of 2.8–3.7 nM, and binding site densities of 180‐297 fmol/mg protein. The displacement of [3H]etorphine by morphine and ethylketocyclazocine displayed Hill coefficients of 0.62 and 0.47, respectively, and revealed receptor sites with much lower affinities than those described by the direct binding of these opiates. On the other hand, both morphine and ethylketocyclazocine displaced [3H]dihydromorphine with similar high potencies (apparent Kds, 3‐4 nM). The results support the feasibility of using brain slices as a cellular preparation to study opioid receptor mechanisms.
Hypothalamo‐neurohypophysial neurons in vitro: Developmental potentials depend on the donor rat stock
Authors: Schilling K. , Pilgrim C. 
Published: January 2005

AbstractPrimary dispersed cell cultures were established from fetal diencephalic tissue derived from two stocks of outbred rats. The overall growth pattern, as followed by phase‐contrast microscopy and visualized by immunocytochemistry for neurofilament proteins and neuron specific enolase, depended on the age of the donor animal. Stock differences were not revealed by these methods. In contrast, when the cultures were immunostained in order to assess the yield of a specific type of cell, i.e., magnocellular hypothalamic neurons, striking differences were observed between the two stocks of rats. Whereas neurophysin‐immunoreactive cells could be grown in culture established from fetal Chbb: Thom rats at embryonic days 14, 15, and 18, no such cells could be detected in cultures derived from CrI: CD (SD) BR rats older than embryonic day 14. These findings may reflect differences in the differentiation schedule and/or requirements for certain epigenietic and trophic factors between magnocellular neuroblasts derived from the two stock of rats.
A major epitope of synthetic rabbit encephalitogen S24 disclosed through the use of a tritiated peptide probe
Authors: Tyrey S. J. , Potter N. T. , Day E. D. , Hashim G. A. 
Published: January 2005

AbstractThe antibody recognition of synthetic rabbit encephalitogen S24 (TTHYGSLPQKG), which had been inactivated by extensive iodination, was fully restored by tritium‐iodine exchange during boron hydride reduction. A highly active form of 3H‐S24 was obtained by reverse‐phase high‐performance liquid chromatography (HPLC) purification of the crude product and could be further separted into three continuous subfractions, the latter two of which were fully active from an immunochemical point of view. A major epitope was diclosed through use of the 3H‐S24 probe, which required the intact S24 peptide for its expression. Confirmation of two linear epitopes previously encountered, GSLPQK and THYGSL, was also obtained, the latter through the use of the third HPLC subfraction of 3H‐S24.
Age‐dependent differences in 125I‐nerve growth factor binding properties of rat adrenal chromaffin cells
Authors: Hofmann H.‐D. , Ebener C. , Unsicker K. 
Published: January 2005

AbstractNerve growth factor (NGF) has ben shown to influence survival, morphology, and transmitter phenotype of young postnatal rat chromaffin cells in vitro. Significant differences in NGF responses of chromaffin cells from newborn rats compared to 8–10‐day‐old ones have been reported. For this reason we studied equilibrium binding and dissociation kinetics of 125I‐NGF on newborn (D1) and 10‐day‐old (D10) rats. Under equilibrium conditions no differences were found between the two cell types, with respect to dessociation constant (∼2.5 × 10−9 M) and receptor number (10–22,000 per cell). In dissociation experiments D10 chromaffin cells exhibited two classes of NGF receptors, similar to those found in other NGF‐responsive cells. Fromfast receptors 125I‐NGF wasreleased rapidly both at 4°C and at 37°C, whereas dissociation from “slow” receptors was observed only at 37°C. The slow receptor class was not found on D1 cells. Instead, more than 50% of specifically bound 125I‐NGF did not dissociate in the presence of excess unlabeled NGF at 37°C. These age‐dependent differences seem to indicate regulatory developmental changes in NGF‐binding properties of rat chromaffin cells.
48‐kilodalton intermediate‐filament‐associated protein in astrocytes
Authors: Abd‐El‐Basset E. M. , Kalnins V. I. , Subrahmanyam L. , Ahmed I. , Fedoroff S. 
Published: January 2005

AbstractWe provide evidence that a protein of 48 kilodaltons (KD), recognized by a normal rebbit serum (F2N), is associated with intermediate filaments (IF) of astrocytes both in cell cultures and in situ. Immunofluorescence staining shows that the F2N serum gives a fibrous staining pattern similar to that seen with antiserum to glial filament protein (GFP), a protein sepecific for IF of astrocytes, and that both proteins are present in the perinuclear fibrous aggregates of IF produced by treating the cells with colchicine. At the ultrastructural level the gold particles decorating the 48‐KD protein are localized on the IF in a linear patterns. This difference in distribution and the fact that the two proteins have different electrophoretic mobilities on SDS gels indicates that the 48‐KD protein although associated with IF is different from GFP.The 48‐KD protein appears to be a distinct, developmentally regulated intermediate‐filament‐associated protein (IFAP), different from other IFAP'S reported to date and the first IFAP described in astrocytes. Its appearance in late developmental stages when motile astroblasts are changing into nonmotile setllate cells suggests that the 48‐KD protein may be involved in cross‐linking the GFP‐containing IF to provide more tensile stregth to the cytoplasm at the expense of flexibility.
Isolation and characterization of cDNA clones encoding epitopes shared with alzheimer neurofibrillary tangles
Authors: Dammerman M. , Goldstein M. , Yen S.‐H. C. , Shafit‐Zagardo B. 
Published: January 2005

AbstractA pool of ten monoclonal antibodies of SDS‐insoluble epitopes of Alzheimer neurofibrillary tangles (NFT) was used to screen and adult brain cDNA expression library. Fourteen clones were isolated, two of which are described. The largest of the clones encodes 80 kD, or approximately 600 amino acids, of microtubule‐associated protein 2 (MAP 2). The MAP 2 region encoded by the cline shares at least two epitopes with human tau, another microtubule‐associated protein which cross‐reacts with NFT. In rat brain mRNA, the MAP 2 cDNA hybridizes to a single transcript of 9.5 kb. In human neuroblastoma mRNA, the MAP 2 cDNA hybridizes, at high stringency, to two transcripts of 9.5 kb and 6 kb. The 6‐kb transcript comigrates with the transcript for tau, as detected by a human tau cDNA. The properties of the MAP 2 cDNA suggest that, in humans, MAP 2 and tau have a common domain which may play a role in NFT formation. Another clone isolated with the anti‐NFT antibodies shares epitopes, but not nucleic acid homology, with the MAP 2 cDNA. This clone detects a single abundant transcript of 1 kb present in RNA from human neuroblastoma and from several non‐neuronal human cell lines. The properties of this cDNA suggest that it encodes a protein other than those previously reported to cross‐react with NFT.
Marcophate colony‐stimulating factor in nerve growth factor preparations
Authors: Erickson‐Miller C. L. , Abboud C. N. , Stach R. W. , Frantz C. N. , Brennan J. K. 
Published: January 2005

AbstractFollowing a report that nerve growth factor preparations have granulocyte‐colony‐stimulating activity, we investigated the presences of colony‐stimulating factors in 7s mouse submaxillary nerve growth factor and its subunits. Macrophage colonies were formed in mouse bone marrow cultures after exposure to preparations of 7s nerve growth factor, the γ subunit, and, to a small extent, the α subunit: the β subunit, which is responsible for the nerve growth function, did not stimulate colony growth. Furthermore, the esteropeptidase activity of the γ subunit was not detected in preparations of macrophage colony‐stimulating factor purified from the giant cell tumor (GCT) cell line. Immunoprecipitation of radiolabeled γ subunit witha polyclonal antibody to L‐cell macrophage colony‐stimulating factor showed a protein band that could represent the γ subunit of nerve growth factor. Separation of the marcophage activity from the esteropeptidase activity of the γ subunit was accomplished on the basis of molecular size. Thus, macrophage colony‐stimulating factor was a contaminant of nerve growth factor produced by the mouse submaxillary gland and copurified with the γ subunit.
Occurrence of phospholipase A1–A2 and lysophosphatidylcholine acyltransferase activities in axolemma‐enriched fractions of brain stem, optic pathway, and cranio‐spinal nerves of the rabbit
Authors: Alberghina M. , Buonacera P. , Agodi A. , Stella A. M. Giuffrida 
Published: January 2005

AbstractAn axolemma‐enriched fraction was isolated and characterized from homogenates of brain stem, pooled optic nerve and tract, and sciatic and hypoglossal nerves of adult rabbits. In these fractions, the phospholipase A1 and A2, as well as the activity of acylCoA:2 ‐ acyl ‐ sn ‐ glycero ‐ 3 ‐ phosphorylcholine acetyl transferase, using 1‐acyl‐ and 2‐acyl‐GPC as acyl acceptors, were studied. The activity of the four enzymes was clearly detecable in the central nervous system (CNS) and peripheral nervous system (PNS) axolemmatic perparations, as well as in other subcellular fractions examined. The axolemma fracions, in which acetylcholinesterase displayed the highest activities, were particularlyenriched in the acylatin reaction enzymes. These latter showed specific activities about twofold higher compared with those of the homogenates and significant correlation with acetylcholinesterase. The noticeable presence of these enzymeactivities in both CNS and PNS axolemma suggests that a deacylation–reacylation system for phospholipids may be operative in this membrane.