bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE BIOSYNTHESIS OF TRIPHOSPHOINOSITIDE BY PURIFIED MYELIN OF PERIPHERAL NERVE
Authors: Iacobelli S. 
Published: October 2006

Abstract—The distribution of diphosphoinositide kinase activity in homogenates and myelin of rabbit nerve was determined by measuring the synthesis of labelled triphosphoinositide. Evidence is presented to show that the biosynthesis of triphosphoinositide in peripheral myelin involves a membrane‐bound diphosphoinositide kinase.
AN ISOTOPIC MICROMETHOD FOR THE MEASUREMENT OF CHOLINESTERASE ACTIVITY IN INDIVIDUAL CELLS
Authors: Koslow S. H. , Giacobini E. 
Published: October 2006

Abstract—A microisotopic method for measuring acetylcholinesterase activity in isolated cells is described. The assay employs [14C]acetylcholine and can measure 7 × 10‐12 moles of acetylcholine hydrolysed/hr in 50‐150 samples per experiment.The method described has been applied to the measurement of cholinesterase activity in individual sympathetic ganglion cells of the cat. It has been shown that under standard conditions the substrate has complete access to the enzymatic site.
ISOLATION AND CHARACTERIZATION OF GLYCOSAMINOGLYCANS IN PERIPHERAL NERVE AND SPINAL CORD OF MONKEY
Authors: Chandrasekaran E. V. , Bachhawat B. K. 
Published: October 2006

Abstract—The isolation of uronic acid‐containing glycosaminoglycans from peripheral nerve and spinal cord of monkey was done by combining the cetyl pyridinium procedure and DEAE‐Sephadex column chromatography. The constituent analyses of the isolated GAG‐fractions indicated that hyaluronic acid, chondroitin‐4‐sulphate, chondroitin‐6‐sulphate, heparan sulphate and a testicular hyaluronidase‐resistant galactosamine‐containing GAG were present in both tissues. Hyaluronic acid was the predominant GAG (63 per cent) in both tissues and its level was much higher than in brain. Chondroitin‐4‐sulphate constituted 16 per cent in both tissues. The levels of heparan sulphate and hyaluronidase‐resistant galactosamine‐containing GAG in these tissues were much lower than in brain. The results indicate that the patterns of GAGs in peripheral nerve and spinal cord of monkey are similar but differ from that of brain.
PURIFICATION AND CHARACTERISTICS OF RNase INHIBITOR FROM PIG CEREBRAL CORTEX
Authors: Takahashi Y , Mase K , Suzuki Y 
Published: October 2006

Abstract— An RNase inhibitor has been purified from pig cerebral cortex by DEAE‐cellulose and hydroxylapatite chromatography and Sephadex G‐100 gel filtration. The purified RNase inhibitor could be resolved into a major band (about 80–85 per cent of total protein) and several minor components by polyacrylamide gel electrophoresis.The ultraviolet absorption curve of the purified RNase inhibitor indicated a typical protein spectrum. The inhibitor was inactivated by digestion with trypsin or prozyme, and by heating at 70ºC for 5 min. The inhibitor was also inactivated by an SH reagent such as p‐chloromercuribenzoate. The inhibitor did not affect RNase T1. It has been suggested that the inhibitor is an acidic protein and also a SH‐protein. The molecular weight of the RNase inhibitor was estimated to be about 60,000.
FRACTIONNEMENT DE L'ORGANE ELECTRIQUE DE LA TORPILLE: LOCALISATION SUBCELLULAIRE DE L'ACETYLCHOLINE SUBCELLULAR FRACTIONATION OF THE ELECTRIC ORGAN OF TORPEDO MARMORATA
Authors: Israël M , Gautron J , Lesbats B 
Published: October 2006

Résumé— L'acètylcholine a été localisée au niveau d'une fraction de vésicules synaptiques isolée à partir de l'organe électrique; le taux d'acétylcholine est fonction de la pression osmotique du milieu. La choline‐acétyltransfèrase (EC 2.3.1.6) n'est pas associée à cette fraction. Les distributions sont comparées à celles de diverses enzymes.Abstract—The electric organ of Torpedo is a purely cholinergic tissue from which fractions of small vesicles 800 Å in diameter may be isolated by homogenisation and centrifugation. The vesicle fraction is rich in acetylcholine. The yield of acetylcholine in the vesicle fraction is dependent on the osmolarity of the homogenisation medium, 800 mosm being optimal. The isolated vesicles themselves lose acetylcholine when subjected to hypo‐osmotic conditions. Choline acetyltransferase (EC 2.3.1.6) behaves as a cytoplasmic enzyme and is not associated with the vesicular fraction. Acetylcholinesterase (EC 3.1.1.7) is found in fractions containing membrane fragments. The cellular distribution of these components of the cholinergic synapse is similar in Torpedo electric organ and mammalian cortex.
PHOSPHOLIPID COMPOSITION OF SOME PARTS OF RAT HYPOTHALAMUS, AND ITS RELATION WITH SOME HISTOCHEMICAL OBSERVATIONS1
Authors: Roozemond R. C. 
Published: October 2006

Abstract—In continuation of a histochemical investigation of phospholipids in rat brain, the content and composition of these lipids in some regions of rat hypothalamus were examined using ultra‐micromethods. The supraoptic and paraventricular nuclei, the anterior area of the hypothalamus, and the adjacent optic chiasma were chosen for this study. The phospholipid content of all of these regions was found to be almost equally high. Proportionally higher amounts were found for phosphatidylethanolamine in the optic chiasma and for phosphatidylcholine in the neurosecretory nuclei. In all regions investigated the sphingomyelin content was nearly the same. From these results it was concluded that the large differences in staining properties of myelinated and unmyelinated areas of the tissue when applying Baker's acid haematein test could not be ascribed to large differences in the content of the Baker‐positive, choline‐containing, phospholipids. Treatment of fixed tissue with cold acetone in order to extract non‐polar lipids that may mask phospholipids, did not abolish the staining differences.The possible involvement of cerebrosides and proteolipids mainly found in myelinated tissue in the Baker reaction is discussed. It is suggested that the differences in staining properties might be ascribed to differences in structure of myelinated and unmyelinated tissue, rather than to differences in the content of Baker‐positive lipids.
CEREBRAL LIPIDS IN A CASE OF SYSTEMIC GM2‐GANGLIOSIDOSIS OF A LATE INFANTILE TYPE1
Authors: Klibansky Chaya , Saifer A. , Feldman N. I. , Schneck L. , Volk B. W. 
Published: October 2006

Abstract—Quantitative analyses performed on the lipids of cerebral grey matter from brains of a normal child and a child with Tay‐Sachs (T‐S) disease were compared with such analyses on the brain of a 6‐year‐old, non‐Jewish male with systemic GM2‐gangliosidosis of a late infantile type (GM2‐LI). Analysis of gangliosides showed a 3·5‐fold increase of total gangliosides in the GM2‐LI brain and a six‐fold increase in the T‐S brain, compared to normal brain. Both pathological brains had similar distribution patterns for gangliosides, with the GM2‐ganglioside component constituting more than 80 per cent of the total. Lipid components in the T‐S brain were below normal values except for lecithin and cholesterol, while in the GM2‐LI brain there were increases in sulphatides, cerebrosides, sphingomyelin and cholesterol. Approximately twice as much ceramide trihexoside was present in the T‐S brain as in the GM2‐LI brain, and none could be detected in the normal brain. The clinical, pathological and biochemical data support the conclusion that this case represents a new variant of systemic late‐infantile gangliosidosis in which there is an accumulation of the GM2‐ganglioside like that in Tay‐Sachs disease.
THYMIDINE METABOLISM AND DEOXYRIBONUCLEIC ACID SYNTHESIS IN THE DEVELOPING RAT BRAIN
Authors: Mori K. , Yamagami S. , Kawakita Y. 
Published: October 2006

Abstract—In growing rat brain, the specific activity of DNA at 12 h after the subcutaneous injection of [3H]thymidine underwent a sharp rise during the first 6 days of life, dropping just as precipitously by 15 days, thereafter continuing to decrease with increasing age.When [3H]thymidine was given to 6‐day‐old rats, a considerable amount was taken up immediately into the brain. Thymidine taken up into the acid‐soluble fraction was readily phosphorylated to its nucleotides, thymidine mono‐, di‐, and triphosphate (TMP, TDP and TTP) within only 30 min following injection. The highest specific activity was found in TTP. The incorporation of of [3H]thymidine into DNA took place over a longer period of time after injection.
THE EFFECT OF MORPHINE ON THE TRANSPORT AND METABOLISM OF INTRACISTERNALLY‐INJECTED LEUCINE IN THE RAT
Authors: Clouet Doris H. , Neidle A. 
Published: October 2006

Abstract—Intracisternally injected l or d‐[14C]leucine was retained longer in the brains of morphine‐treated rats than in saline‐injected control animals. This resulted in higher levels of the labelled leucine and of labelled metabolites of the l‐isomer in free pools of brain tissue. However, the absolute levels of brain amino acids and the relative distribution of radioactivity among l‐leucine metabolites in brain were unaffected by treatment with morphine, indicating that no disturbance of leucine oxidation through the citric acid cycle was produced by the drug. The inhibition of protein synthesis caused by acute administration of morphine was calculated to be greater than previously reported since morphine treatment increased the specific radioactivity of the free pool of leucine in brain following the intracisternal injection of the labelled amino acid. Possible mechanisms responsible for these morphine effects are discussed.
SURFACE CHARGE OF CHOLINE ACETYLTRANSFERASE FROM DIFFERENT SPECIES
Authors: Fonnum F. 
Published: October 2006

Abstract—The adsorption of partially purified choline acetyltransferase (ChAc) from cat, rat, guinea‐pig and pigeon brains by the cation exchange resins, CM‐Sephadex (C‐50) and Amberlite CG‐50 II, was studied at various pH values and ionic strengths. ChAc from cat and rat were more strongly adsorbed by cation exchangers and therefore have a stronger net positive surface charge than those from guinea pig and pigeon. Experiments showed that the difference in adsorption between these two groups of enzymes could not be explained by overloading of the resin, by competitive effect of other proteins present in the enzyme preparations or by the presence of any component suppressing the adsorption of ChAc in any of the enzyme preparations. The adsorption of ChAc by a cation exchanger is very similar to its binding to synaptosome membranes. The significance of the positive surface charge of ChAc in studies on the compartmentation of ChAc in synaptosomes is discussed.
EFFECTS OF HYPOPHYSECTOMY ON RNA METABOLISM IN RAT BRAIN STEM
Authors: Gispen W. H. , Wied D. De , Schotman P. , Jansz H. S. 
Published: October 2006

Abstract— Ribosomal aggregates were isolated from rat brain stem and characterized as polysomes by sedimentation analysis and by their sensitivity to RNase and EDTA treatment.Three weeks following hypophysectomy there was a significant decrease in the content of large polysomes in the rat brain stem. The incorporation of radioactive uridine into RNA was studied using a double‐labelling technique with [3H]‐ and [14C]uridine and labelling periods of 70 and 180 min. It was found that after hypophysectomy the incorporation of radioactive uridine into total, nuclear and cytoplasmic RNA and in polysomes was decreased after 70 and 180 min. Information on the nature of the rapidly‐labelled RNA in the various subcellular fractions was obtained by sucrose gradient sedimentation analysis.After 70 min of labelling the nucleus contained heterogeneous RNA with a considerable fraction of RNA sedimenting faster than 28 S. In the cytoplasmic fraction heterogeneous 4 to 30 S RNA was found, presumably associated with RNP particles, whereas after 180 min the polyribosomal aggregates were also labelled.The present results indicate a profound effect of hypophysectomy on the metabolism of all species of brain RNA investigated.
CHOLESTEROL ESTERS AND HYDROLYTIC CHOLESTEROL ESTERASE DURING WALLERIAN DEGENERATION1
Authors: Mezei Catherine 
Published: October 2006

Abstract—To study the involvement of cholesterol esters in myelination and demyelination, we determined the concentration of free cholesterol and cholesterol esters and the activity of hydrolytic cholesterol esterase (sterol ester hydrolase; EC 3.1.1.13) in hen sciatic nerve during Wallerian degeneration. A progressive increase in the ratio of cholesterol ester to free cholesterol was observed in the degenerating nerve at 8, 16 and 32 days after nerve section. Hydrolytic cholesterol esterase activity decreased progressively in the degenerating nerves at the same time.In addition we measured the ratio of RNA to DNA, and the activity of the NADP+‐dependent isocitrate dehydrogenase [L8‐isocitrate: NADP oxidoreductase (decarboxylating); EC 1.1.1.42] at 8, 16 and 32 days after nerve section. The RNA to DNA ratios decreased progressively in the degenerating nerves. NADP+‐dependent isocitrate dehydrogenase increased in activity after nerve section, reaching a peak at 16 days.
DEVELOPMENTAL CHANGES OF CHOLINESTERASES AND MONOAMINE OXIDASE IN CHICK EMBRYO SPINAL AND SYMPATHETIC GANGLIA
Authors: Giacobini G. , Marchisio P. C. , Giacobini E. , Koslow S. H. 
Published: October 2006

Abstract— Total cholinesterase, acetylcholinesterase, (AChE) and monoamine oxidase (MAO) activity and protein content were determined throughout the embryonic life of the chick in spinal and sympathetic ganglia. The greatest part of total cholinesterase activity was due to AChE.AChE and MAO activity increased in both spinal and sympathetic ganglia very similarly from the 6th to the 12th day of incubation; from this day on a significant divergence occurred, mainly owing to a steady fall in spinal ganglion AChE, which decreased to approximately one tenth of the maximum value. The ratio of MAO activity in sympathetic and spinal ganglia increased from the 8th day onwards and approached 5·0 at hatching. The ratio between sympathetic and spinal ganglia, for AChE, choline acetylase (ChAc) and MAO activity, suggests a relationship between the maturation of the synapse in the sympathetic ganglia and the maximal activity of these enzymes.
COMPOSITION OF CEREBRAL LIPIDS IN MURINE LEUCODYSTROPHY: THE QUAKING MUTANT
Authors: Hogan E. L. , Joseph K. C. 
Published: October 2006

Abstract—The composition of sphingolipids and phospholipids of mouse brain during myelination was determined in the Quaking mutant, which manifests a genetic disorder of myelin formation, and in littermate controls. The biochemical changes during myelination in the brains of the controls corresponded quantitatively with previous findings in a different strain of mice. The Quaking mutant exhibited concentrations of sphingolipids and phospholipids in brain which were comparable to those of controls in the early stage of myelination but the tissue content failed to increase with maturation. The greatest differences occurred in the cerebrosides which at 65 days of postnatal age were only 10 per cent of control levels. During development the pattern of cerebral levels of sphingomyelin, plasmalogen and total phospholipid in the mutants tended to resemble that of the cerebrosides.The defect in the Quaking mutant is compatible with a failure in maturation of myelin. These findings have been compared with those in the Jimpy mutant, a different genetic disorder of myelin in the mouse previously studied in a similar fashion. The Jimpy mutant is characterized by a quantitatively more pronounced deficiency of myelin lipids and a decline in cerebrosides during brain development.
DIFFERENTIAL METABOLISM OF RNA IN NEURONAL‐ENRICHED AND GLIAL‐ENRICHED FRACTIONS OF RAT CEREBRUM
Authors: Flangas A. L. , Bowman R. E. 
Published: October 2006

Abstract—Cerebral tissue of rat, disrupted by passage through a custom‐designed tissue press, was diluted to a 10% (w/v) cellular suspension in 10% (w/v) Ficoll and was then fractionated in the Spinco Model L ultracentrifuge into: (1) two enriched cellular layers (alpha and beta) in an isopycnic Ficoll gradient in the Spinco 40 angular rotor; or (2) into four layers (A, B, C, and D) in a discontinuous Ficoll gradient in the Spinco SW 39 swinging bucket rotor. The cellular composition of these layers was identified microscopically and enzymically as either glial‐enriched (alpha and B layers) or neuronal‐enriched (beta and C layers) fractions of cerebral cortex. Portions of the neuronal and glial fractions were used for determinations of total nitrogen, and for colorimetric determinations of carbonic anhydrase activity (a glial cell marker). These data established that glial contamination of the neuronal‐enriched layer averaged 6·5 per cent. The data also indicated glial enrichment of Layer B, although no quantitative assessment of the amount of neuronal contamination was possible.The kinetics of metabolism of RNA in the glial‐enriched and neuronal‐enriched fractions were studied from 0·5 to 16 h after‐intracisternal injection of either [3H]cytidine or [3H]orotic acid. In addition, the incorporation of [3H]cytidine into crude nuclear and cytoplasmic components of the layers was studied by the use of 1 h pulses. Our findings indicated greater incorporation of [3H]cytidine into nuclear fractions than into cytoplasmic fractions at 1 h and greater incorporation of both precursors into neuronal‐enriched fractions than into glial‐enriched fractions at all pulse times.
THE INCORPORATION OF [14C]LYSINE INTO THE PROTEIN OF THE GUINEA PIG CENTRAL AUDITORY SYSTEM1
Authors: Davies W. E. 
Published: October 2006

Abstract—The incorporation of [14C]lysine into various brain proteins was studied. The proteins of different areas of the auditory system and cortical subcellular fractions were analysed using a disc electrophoretic technique that allows both protein and radioactivity assays along the gels. The highest level of incorporation was found in the mid brain nuclei, particularly the inferior colliculus, and was lowest in the auditory cortex proteins. This was true for both saline soluble proteins and proteins solubilized by Triton X‐100 treatment. Of the subcellular fractions, the highest level of activity was found in the microsomal fraction. Considerable radioactivity was also found in the proteins isolated from the synaptosome‐rich fraction. Of particular interest in this fraction was a slow migrating protein band which was soluble in Triton X‐100, had a high specific activity, and appeared to be synaptosome specific. These observations are in concurrence with the hypothesis that the nerve ending contains protein synthesizing machinery.
EFFECTS OF COLCHICINE ON AXONAL TRANSPORT IN PERIPHERAL NERVES
Authors: Sjöstrand J. , Frizell M. , Hasselgren P.‐O. 
Published: October 2006

Abstract—Colchicine injected intracisternally markedly inhibited the rapid migration (300‐400 mm/day) of labelled proteins in the hypoglossal and vagus nerve of the rabbit. The transport of acetylcholinesterase (EC 3.1.1.7) and choline acetyltransferase (EC 2.3.1.6) previously shown to move with the slow (5‐26 mm/day) phase of axoplasmic transport in these nerves, was only partially blocked. In view of this differential effect on axonal flow, we suggest that the neurotubules, on which colchicine acts preferentially, are primarily involved in the rapid (300‐400 mm/day) axoplasmic flow. After local injection of colchicine into the nerves both the rapidly migrating labelled proteins and the enzymes (AChE and ChAc) accumulated above the site of injection to the same degree as they accumulate above a nerve ligation. Since this blockage of enzyme transport occurred after concentrations of colchicine much higher than those used for intracisternal injections these findings after local injection may represent more severe effects on axonal transport systems.
AXONAL TRANSPORT OF PROTEINS IN THE HYPOTHALAMO‐NEUROHYPOPHYSIAL SYSTEM OF THE RAT
Authors: Norströ A. , Sjöstrand J. 
Published: October 2006

Abstract—Axonal transport of proteins in the hypothalamo‐neurohypophysial system of the rat was studied after a local injection of [35S]cysteine in the region of the supraoptic nucleus. The migration of labelled proteins was followed by measuring the specific radioactivity of the proteins in various parts of the hypothalamo‐neurohypophysial tract. Between 2 and 4 h after the isotope injection there was a sharp increase in the protein‐bound specific radioactivity of the posterior pituitary lobe, demonstrating that a transport of 35S‐labelled proteins had occurred from the supraoptic nucleus to the neurohypophysis. The rate of the transport was 2‐3 mm/h. During the first 24 h after the injection a continuous accumulation of labelled material occurred in the neural lobe. Considerable radioactivity could still be recovered 6 days after the isotope injection.Fractionation of the neurohypophysial proteins by polyacrylamide gel electrophoresis revealed that approximately 90 per cent of the radioactivity of the soluble proteins was recovered in a single protein fraction. Labelling of this fraction was not observed until 2 h after isotope injection. The radioactivity increased markedly up to 4 h. It is suggested that this protein component is involved in the neurohypophysial response to osmotic stress since the protein disappeared from the posterior lobe upon dehydration of the rat.
ELECTROPHORETIC CHARACTERIZATION OF BASIC PROTEINS IN ACID EXTRACTS OF CENTRAL NERVOUS SYSTEM TISSUE
Authors: Martenson R. E. , Deibler Gladys E. , Kies Marian W. 
Published: October 2006

Abstract—A technique has been outlined for identification of myelin basic proteins in mixtures of CNS proteins. Myelin basic proteins can be recognized easily by high cathodic mobility at low pH, a unique electrophoretic pattern exhibited at high pH and a characteristic colour when complexed with Amido black. The major protein extracted at pH 3·0 from either brain or spinal cord is myelin basic protein. In the low pH electrophoretic pattern of these extracts it is the most conspicuous component and the component migrating farthest cathodically; it does not appear in comparable electrophoretic patterns of liver extracts. Guinea pig myelin basic protein appears as a single dense blue‐green band in low pH electrophoretic patterns, in contrast to the other proteins which are stained greyish‐blue or greyish‐purple by Amido black. The pattern of rat myelin basic protein is similar except that it consists of a pair of dense blue‐green bands.A third characteristic which facilitates the identification of myelin basic proteins in mixtures is a considerable cathodic mobility and electrophoretic heterogeneity at pH 10·6. Most other basic CNS proteins barely penetrate the gel at this pH. We have also examined in detail the behaviour of two other components of pH 3·0 extracts which migrate close to myelin basic protein at low pH. Both are present in pH 3·0 extracts of liver and brain but not of spinal cord, and both stain grey instead of blue‐green, a characteristic which readily distinguishes them from myelin basic protein. Neither of these components affects the characteristic pattern of microheterogeneity observed in high pH electrophoretograms of myelin basic proteins. One of these components has been purified and tentatively identified as lysine‐rich histone F1.
ISOLATION OF TWO PANTOTHEINE‐CONTAINING ACIDIC PROTEINS FROM MONKEY BRAIN
Authors: Reichelt K. L. 
Published: October 2006

AbstractThe isolation of two acid‐soluble proteins from Macaca irus brain is reported. The proteins contained 34 and 35.6 per cent polar amino acids, respectively. One protein had a mol. wt. of approx. 37,100 and the other of 23,000 with subunits of 11,500. Each protein contained 4′‐phosphopantetheine, which was hydrolytically determined as taurine and β‐alanine and microbiologically as pantothenate. The smaller protein is found to be present in the supernatant following homogenization both in 0‐32 M‐sucrose and in 0‐32 M‐sucrose with 40 mm‐NaCl. The larger protein is also mainly present in the supernatant fluid. The function of these proteins is unknown, but the mol. wt. 23,000 species could be acetylated from glucose and acetate in mouse brain tissue slices and the acetyl groups could be isolated as the hydroxamate.