bluuebunny/crossref_metadata_2025_split huggingface dataset:
Developing rod photoreceptors from normal and mutant Rd mouse retinas: Altered fatty acid composition early in development of the mutant
Authors: Scott B. L. , Racz E. , Lolley R. N. , Bazan Nicolas G. 
Published: January 2005

AbstractThe phospholipid and fatty acid contents of developing rod photoreceptor cells were determind in dissociated photoreceptor cells obtained from normal mice and from rd mice exhibiting an inherited retinal degeneration. Photoreceptors were dissociated from retinas by mechanical agitation after mild protease treatment and characterized by light and electron microscopy. Phospholipid classes were isolated by thin‐layer chromatography, and fatty acyl groups separated and quantitated by capillary gas‐liquid chromatography. Developing photoreceptor cells of normal retinas accumulated all phospholipid classes, but in proportions which shifted with age. The mole % contents of phosphatidylcholine (PC) and phosphatidylinositol (PI) decreased with age, whereas phosphatidylethanolamine (PE) and phosphatidylserine (PS) increased. The content of the polyunsaturated fatty acid docosahexaenoate (22:6), expressed as nmol/μg lipid phosphorus, increased rapidly during development, whereas arachidonate (20:4) content tended to decline. Mono‐unsaturated fatty acid levels (palmitoleate, 16:1; oleate, 18:1) declined with age. Among saturated fatty acids, palmitate (16:0) decreased during normal development, whereas stearate (18:0) increased. The total mass of phospholipid/photoreceptor cell in the normal, adult mouse retina was estimated to be approximately 14 pg.The total phospholipid content and mole % distribution of individual phospholipid classes in immature rd photoreceptors were similar to values for normal cells. In contrast, significant changes in fatty acid composition were detected between immature rd cells and normal cells. Rd cells generally had higher levels of saturated (myristate, 14:0; palmitate, 16:0) and monounsaturated fatty acids (oleate, 18:1) and lower levels of polyunsaturated fatty acids (arachidonate, 20:4; docosahexaenoate, 22:6), suggesting that fatty acid metabolism is altered by expression of the rd gene and/or by the associated impairment of photoreceptor cell differentiation.
Tyrosine hydroxylase and serotonin containing cells in embryonic rat rhombencephalon: A whole‐mount immunocytochemical study
Authors: König Norbert , Wilkie M. B. , Lauder J. M. 
Published: January 2005

AbstractRhombencephala from rat embryos were processed as whole‐mounts for immunocytochemical detection of monoaminergic cell populations, using antibodies to tyrosine hydroxylase (TH) and serotonin (5‐HT). Specific advantages of the whole‐mount technique over the classical serial‐section method were that even isolated immunoreactive (IR) cells could be detected easily, and three‐dimensional relationships could be ascertained without the need for serial reconstruction.Embryos between embryonic days (E) 12 and 16 (the day following nocturnal mating being considered as E1) were used in this study. Both TH and 5‐HT immunoreactivities were already detectable at E12, even in the smallest embryos (crown‐rump length: 6mm), but there was a striking difference in the number and regional distribution of these two types of IR cells. TH was expressed in several cell groups located in the rostral rhombencephalon (the presumed anlage of the A4‐7 complex) as well as in the caudal rhombencephalon (the presumed anlagen of groups A1‐2 and C1‐3), whereas 5‐HT was expressed in very few cells located near the rostral border of the rhombencephalon (presumed anlage of the B4‐9 complex). Although the three‐dimensional distribution of the TH‐IR cell groups underwent some modifications during the period studied, its general pattern remained relatively stable after E12. This contrasted with the sequential appearance of the 5‐HT‐IR cell groups and their spatial transformations during this period.Using the rhombencephalic isthmus as a landmark, we found that conspicuous 5‐HT‐IR fibre bundles penetrated into the mesencephalon from E13 onwards, but that the 5‐HT IR cell bodies were exclusively located caudal to the borderline between the mesencephalon and the rhombencephalon (the rhombencephalic isthmus). We therefore suggest the term “rostral rhombencephalic raphe nuclei” for the rostral 5‐HT cell groups instead of “mesencephalic raphe nuclei,” which is a misnomer.Close spatial association between TH and 5‐HT‐IR elements was observed mainly in the caudal rhombencephalon, where 5‐HT‐IR fibres coursed through an area containing numerous TH‐IR cell bodies (the presumed anlagen of groups A1‐2 and C1‐3).
Early and late appearance of neurofilament phosphorylated epitopes in rat nervous system development: In vivo and in vitro study with monoclonal antibodies
Authors: Dahl D. 
Published: January 2005

AbstractNeurofilament phosphorylation in rat nervous system development was studied by indirect immunofluorescence with monoclonal antibodies reacting with phosphorylated epitopes in tissue sections and in primary dissociated cultures. The antibodies either decorated neurofilaments shortly after their appearance or after a considerable delay (from 4 to 9 days in vivo and from 12 to 27 days in vitro), thus suggesting the existence of at least two classes of phosphorylated epitopes. With most antibodies there was a good correlation between in vivo and in vitro findings as to the early or late appearance of phosphorylated epitopes. Monoclonal NE14 was the main exception in that immunoreactivity with this antibody was present in 1‐day cultures, while it only occurred 4 days after the first appearance of neurofilaments in vivo. The effect of phosphorylation on neurofilament structure and function remains to be determined. Neurofilament expression is an early phenomenon in ontogeny coinciding with neuronal differentiation. It is possible that late phosphorylation events may stabilize the axonal cytoskeleton following the massive loss of axons that occurs in several fiber tracts during late fetal and neonatal life.
Lipids of the developing human retina. I. Total fatty acids, plasmalogens, and fatty acid composition of ethanolamine and choline phosphoglycerides
Authors: Martinez M. , Ballabriga A. , Gil‐Gibernau J. J. 
Published: January 2005

AbstractThe total fatty acid composition of the human retina was studied during early normal development and compared to that found in infancy and in adulthood. The retina of an infant undernourished prenatally and of two malnourished postnatally were also studied and compared to the normal values for the age. The fatty acid patterns of ethanolamine phosphoglycerides (EPG) and choline phosphoglycerides (CPG) were also studied. Total and ethanolamine plasmalogens (EP) were estimated by the aldehyde dimethyl acetal (DMA) content of total lipids and of EPG, respectively. After acid methanolysis, analyses of fatty acid methyl esters (FAME) and of DMA were effected by capillary GLC on a single 30 m long, SP‐2330, capillary column. The main developmental fatty acid changes were an increase in 22:6ω3, 22:5ω3 and 20:3ω6 and a decrease in 20:4ω6. The 22:6ω3/20:4ω6 ratio increased in a very significant, parabolical way throughout development. In contrast to the brain, the proportion of ethanolamine plasmalogens decreased with maturation, whereas the ratio 18DMA/16DMA increased. The two postnatally malnourished infants had a very significant increase in retinal 22:5ω6, but only the child that had been fed on a very unbalanced ω3/ω6 diet since 25 weeks of gestation showed an important decrease in retinal 22:6ω3.
Acylation in vitro of the myelin proteolipid protein and comparison with acylation in vivo: Acylation of a cysteine occurs nonenzymatically
Authors: Ross N. W. , Braun P. E. 
Published: January 2005

AbstractCharacteristics of fatty acylation of myelin proteolipid protein (PLP) in vitro were compared with the corresponding process in vivo. Rapid and efficient separation of labelled PLP from other proteins and lipids was effected by extraction into chloroform/methanol/0.1 N HCl (10/10/1) and chromatography on Sephadex LH‐60 in the same solvent. Covalent linkage of [3H]‐palmitate to PLP was demonstrated by repetitive chromatography on LH‐60, thin layer chromatography, and polyacrylamide gel electrophoresis. Reductive cleavage with sodium borohydride of PLP acylated in vitro or in vivo yielded [3H]‐hexadecanol, identifying at least one of the acyl linkages as a thiolester bond. When PLP was acylated with acyl‐CoA as the fatty acid donor, the reaction occurred non‐enzymatically as supported by the following observations: (1) acylation activity increased with increasing pH above pH 7.5, (2) acylation activity was heat stable, (3) acylation activity was not removed from PLP during purification in organic solvents or in Triton X‐100–containing buffers, and (4) acylation of tryptic fragments occurred in the absence of an exogenously added enzyme source. The relevance of in vitro fatty acylation of PLP to that in vivo was confirmed by comparison of proteolytically derived peptide maps that showed that likely the same domain of PLP was acylated in vitro and in vivo.
Monoclonal antibodies made to chick mesencephalic neural crest cells and to ciliary ganglion neurons identify a common antigen on the neurons and a neural crest subpopulation
Authors: Barald Kate F. 
Published: January 2005

AbstractWe previously reported the production of monoclonal antibodies (Mabs) that identified cell surface components of cultured chick and quail ciliary ganglion (CG) neurons and of a subpopulation of neural crest (NC) cells from 31‐hr chick embryos (stage 9). Here we demonstrate that another Mab, CG‐14, which was prepared to nitrocellulose‐immobilized, lightly fixed (0.125% paraformaldehyde) mesencephalic NC cells from 31‐hr (stage 9) chick embryos, labels the same antigen(s) recognized by CG‐1 and CG‐4 on both the CG neurons and the subpopulation of NC cells. All three Mabs label a polypeptide of 75 kD on Western blots of one‐dimensional SDS‐polyacrylamide gels. CG‐14 blocked the binding of CG‐1 and/or CG‐4 to the 75 kD band on Western blots and blocked the binding of CG‐1 and CG‐4 to CG and NC cells. CG‐1 and/or CG‐4 antibodies, in turn, blocked the binding of CG‐14 to Western blots, as well as NC and CG cells. We had previously shown that antibodies CG‐1 and CG‐4 were synergistically cytotoxic for the majority (95%) of cultured CG neurons in vitro in the presence of guinea pig complement. Here we show that the antibodies, which are both of the γ2a subclass, are also cytotoxic for the NC cells that they label in vitro. After the cells are ablated in culture, no other cells bearing the antigen(s) recognized by any of the three Mabs appear over a 2.5‐week period. CG‐14, however, is not cytotoxic for either the CG or NC cell populations alone or in combinations with CG‐1 or CG‐4.These results confirm our original observation that cultured CG neurons and NC cells share cell‐surface antigen(s). The antigen recognized by all three Mabs appears to be the same whether the immunogen used to produce the antibodies was CG neurons or NC cells. This finding encourages us to continue tests of the hypothesis that the subpopulation of mesencephalic neural crest cells contributes to the formation of the ciliary ganglion in the embryo. Further characterization of the antigen appears in the accompanying paper.
Myelin basic protein and transferrin characterize different subpopulations of oligodendrocytes in rat primary glial cultures
Authors: de los Monteros A. Espinosa , de Vellis Jean 
Published: January 2005

AbstractThe iron transport glycoprotein, transferrin (Tf), localizes exclusively in oligodendrocytes in brain tissue sections. Previously, we showed that Tf is also expressed in oligodendrocytes in primary cultures established from newborn rat brains. Its developmental appearance precedes that of galactocerebroside (GC). In this study, Tf expression in primary brain cell cultures was investigated over a 4‐week period in relation to GC and myelin basic protein (MBP), respectively, early and late markers of oligodendrocyte development. From 9 days in vitro and thereafter, all Tf+ cells were also found to be GC+. With increasing age the number of Tf+ cells decreased while the number of MBP+ cells increased. However, less than 10% of oligodendrocytes co‐expressed Tf and MBP at any age. MBP+ cells were largely found in cell clusters which increased in size and number with age in culture. Interestingly, Tf+ cells were located around the clusters of MBP+ cells which displayed elaborate branched processes. The transient expression of Tf in oligodendrocytes which become MBP+, suggests a role for Tf in the early stages of myelinogenesis. The results also demonstrate the existence of three phenotypically distinct populations of oligodendrocytes. A new model of developmental and functional subpopulations of oligodendrocytes is proposed.
Nerve growth factor rapidly stimulates arachidonate metabolism in PC12 cells: Potential involvement in nerve fiber growth
Authors: DeGeorge J. J. , Walenga R. , Carbonetto S. 
Published: January 2005

AbstractHomogenates prepared from pheochromocytoma (PC12) cells that are extending nerve fibers in response to nerve growth factor (NGF) have an increased capacity to metabolize exogenous arachidonate compared with homogenates prepared from cells untreated with NGF. These changes are not a consequence of cell attachment, since they are also seen in NGF‐treated PC12 cells grown in suspension and are not found in attached cells grown in the absence of NGF. This NGF‐stimulated increase in arachidonate metabolic capacity occurs rapidly and before the extension of nerve fibers. In contrast to NGF, epidermal growth factor does not alter the metabolism of exogenous arachidonate by PC12 cells. Radioimmunoassay of medium from PC12 cultures indicates that intact cells produce and release increased amounts of prostaglandin (PGE) in response to NGF.Drugs that inhibit arachidonate liberation from membrane phospholipids (mepacrine or 4‐bromphenacyl bromide) block NGF‐stimulated nerve fiber growth by PC12 cells. Selective inhibitors of cyclooxygenase metabolism of arachidonate (indomethacin and aspirin) fail to block growth, but inhibitors of lipoxygenase metabolism (baicalein, BW755, and eicosatetraynoic acid) are potent blockers. In cultures of dorsal root ganglion neurons, inhibitors of arachidonate release (mepacrine, 4‐bromphenacyl bromide) or its subsequent metabolism by lipoxygenases (nordihydroquaiaretic acid, eicosatetraynoic acid) also prevent the early morphological events of nerve fiber growth.Our data suggest that NGF rapidly and specifically increases the capacity of PC12 cells to synthesize arachidonate metabolites, and that arachidonate metabolism may be important in nerve fiber growth by both PC12 cells and dorsal root ganglion neurons.
Brain macrophages synthesize interleukin‐1 and interleukin‐1 mRNAs in vitro
Authors: Hetier E. , Ayala J. , Denèfle P. , Bousseau A. , Rouget P. , Mallat M. , Prochiantz A. 
Published: January 2005

AbstractAmoeboid microglial cells (brain macrophages) were purified from early post‐natal mouse brain cultures. The percentage of cells stained with an anti‐Mac‐1 antibody was > 95%. Stimulation of these brain macrophages by lipopolysaccharides induced the synthesis of interleukin‐1 (IL‐1), which, in part, remained associated with the cell surface and, in part, was released into the culture medium. In contrast, pure primary astrocyte cultures and cell lines of transformed or immortalised astrocytes did not synthesise significant amounts of IL‐1, demonstrating that amoeboid microglia and not astrocytes synthesise IL‐1 in vitro. These physiological data were confirmed by RNA hybridisation studies showing that, on LPS treatment, brain macrophages synthesise significant amounts of IL‐1α and IL‐1 β mRNAs.
Expression of an engrailed‐like gene during development of the early embryonic chick nervous system
Authors: Gardner C. A. , Darnell D. K. , Poole S. J. , Ordahl C. P. , Barald K. F. 
Published: January 2005

AbstractThe engrailed gene has been identified in Drosophila as an important developmental gene involved in the control of segmentation. Here we describe the embryonic expression of a chicken gene, ChickEn (Darnell et al.: J Cell Biol 103(5):311a, 1986), which contains homology to the Drosophila engrailed gene. Northern blots of early chick embryo tissue poly(A)+ RNA resulted in hybridization to at least three bands expressed predominantly in the brain/head region when probed with ChickEn genomic fragments. Eight cDNA clones generated from embryonic day 6 (stage 29–30) chick brain poly(A)+ RNA are identical in their nucleotide sequence with the ChickEn genomic clone. In situ hybridization to sections of 4‐day (stage 24) embryos indicated that ChickEn transcripts were concentrated in the posterior mesencephalon and anterior metencephalon. In cultures of chick cranial neural crest cells (eight to nine somites; stage 9) ChickEn transcripts were localized in a subset (approx. 8%) of cells examined after 2 days in culture.A mouse monoclonal antibody, inv‐4D9D4, made by Coleman and Kornberg recognizes the engrailed‐like homeo domain of the engrailed and invected proteins (Martin‐Blanco, Coleman, and Kornberg, personal communication). Patel, Coleman, Kornberg and Goodman (unpublished) have shown that this antibody binds to the hindbrain of 2‐day‐old chick embryos. We have confirmed these results and shown that this antibody binds to the same region of 4‐day (stage 24) chick brains that in situ hybridization showed contained ChickEn transcripts. This antibody also recognizes a homeo domain‐containing ChickEn peptide expressed as a beta‐galactosidase fusion protein in Drosophila cell culture. We have not detected ChickEn protein in any tissue prior to eight to nine somites (stage 9). These results delineate the major expression pattern of the ChickEn gene during early (prior to stage 30) embryonic development in the chick.
Human fetal schwann cells in culture: Phenotypic expressions and proliferative capabibility
Authors: Kim S. U. , Yong V. W. , Watabe K. , Shin D. H. 
Published: January 2005

AbstractIn this report we examined the phenotypic expressions and the proliferative capability of cultured human fetal Schwann cells. Antigens that were expressed included laminin, nerve growth factor receptor, neural cell adhesion molecule, S‐100 protein, and that recognized by the monoclonal antibody HNK‐1. In addition, HLA‐A,B,C and HLA‐DR, respectively, class I and class II antigens of the major histocompatibility complex, were demonstrated on Schwann cells. Mitotic capability was high, with an average of 34% of Schwann cells undergoing proliferation over a 2‐day period.
Identification of a cDNA clone specific for the neural cell adhesion molecule AMOG
Authors: Pagliusi S. , Antonicek H. , Gloor S. , Frank R. , Moos M. , Schachner M. 
Published: January 2005

AbstractA cDNA clone of the neural cell adhesion molecule AMOG was isolated from a lambda gt10 library constructed from 8‐day‐old mouse brain poly(A) + RNA with a 17mer oligonucleotide probe designed from a nonapeptide sequence obtained from tryptic peptides of AMOG. The cDNA clone expressed as a fusion protein that is recognized by polyclonal AMOG antibodies; conversely, polyclonal antibodies prepared against the fusion protein react with AMOG. The clone contains the full sequence derived from the nonapeptide. Of all tissues tested, only brain expresses detectable levels of AMOG by ELISA and Northern blot analyses, indicating a high correlation in expression at the protein and mRNA levels. Both brain and astrocytes express a 3 kb long mRNA, which appears to be encoded by a single gene.
Adult retinal ganglion cells retain the ability to regenerate their axons up to several weeks after axotomy
Authors: Thanos S. , Vanselow J. 
Published: January 2005

AbstractThe present work was to elucidate whether the ability of adult central neurons to regrow their lesioned axons is retained for long periods of time. Using the rat retina as an experimental paradigm, the optic nerve was lesioned by crush in situ. Up to 6 weeks after the trauma, the optic nerve (ON) was again exposed and transected close to the first lesion and autologous sciatic nerve segments were anastomosed at the ocular ON stump. Alternatively, the retina corresponding to the lesioned ON was dissected for in vitro cultivation 1–6 weeks after the crush‐axatomy was applied. Both experimental strategies revealed a regrowth of the lesioned retinal ganglion cell (RGC) axons. When peripheral nerve (PN) segments were grafted without previous ON crush, axon stumps started to reelongate and to penetrate the grafted piece of nerve 6 days later. In contrast, when the PN graft was apposed to the ON stump 1–6 weeks after crush, it was penetrated by regrowing axons within 24 hr. Maximal numbers of regenerating axons were observed if transplantation occurred within the first week after the crush. The numbers of axons decreased progressively if transplantation was performed later than 1 week postcrush and approximated zero values at the 6th week. When the noncrushed retina was explanted and cultured in vitro in a chemically defined, serumfree medium, there was almost no extending fiber. In contrast, explantation of the retina for which the ON had been precrushed in situ resulted in massive regrowth of RGC axons. The numbers of regenerating axons and their temporal changes paralleled those described for the transplantation experiments. The data indicate that axomotized central neurons sustain their ability for axon regrowth over considerable periods of time and can make use of this elongation capability if regeneration‐permissive environmental conditions are provided.
Effect of cocaine and cocaine congeners on veratridine‐induced depolarization in mouse cerebrocortical synaptoneurosomes
Authors: Zimányi I. , Wang E. , Lajtha A. , Reith M. E. A. 
Published: January 2005

AbstractStructure‐activity relationships were determined for cocaine congeners in counteracting the depolarization induced by the action of veratridine on voltage‐dependent sodium channels of synaptoneurosomes from mouse brain cortex, and their potency was compared to those determined previously on Na+ uptake and batrachotoxinin binding. Cocaine, norcocaine, (+)‐pseudococaine, (‐)‐pseudococaine, (+)‐neopseudococaine, benzoyltropine, benzoylpseudotropine, ecgonine methylester, atropine, WIN‐35,428, WIN‐35,140, WIN‐35,065‐3, WIN‐35,004, and procaine were tested for their potency in inhibiting depolarization as measured by the distribution of the lypophilic cation [3H]triphenylmethylphosphonium across the membrane. All of the tested compounds inhibited the veratridine‐induced depolarization in a competitive manner. The structure‐activity relationships were similar to those for inhibition of 22Na+ uptake in mouse brain homogenates, and the potency of these local anesthetics in inhibiting veratridine‐induced uptake of [3H]triphenylmethylphosphonium correlated well with their potency in inhibiting [3H]batrachotoxinin A 20‐α‐benzoate binding in mouse brain synaptosomes.