bluuebunny/crossref_metadata_2025 huggingface dataset:
Anisotropy of photofragment recoil as a function of dissociation lifetime, excitation frequency, rotational level, and rotational constant
Authors: Kim Hahkjoon , Dooley Kristin S. , North Simon W. , Hall Gregory E. , Houston P. L.
Published: October 2006

Quantum mechanical calculations of photofragment angular distributions have been performed as a function of the frequency of excitation, the lifetime of the dissociative state, the rotational level, and the rotational constant. In the limit of high J values and white, incoherent excitation, the general results are found to agree exactly with both those of Mukamel and Jortner [J. Chem. Phys. 61, 5348 (1974)] and those of Jonah [J. Chem. Phys. 55, 1915 (1971)]. Example calculations describe how the anisotropy is dependent on the degree of broadening, the rotational constant, the initial rotational level, and the frequency of excitation. Applications are also made to interpret experimental results on the photodissociation of ClO via the 11-0, 10-0, and 6-0 bands of the AΠ3∕22–XΠ3∕22 transition and on the photodissociation of O2 via the 0-0 band of the EΣu−3–XΣg−3 transition.
Remote experiment of ultrashort-pulse reflectometry for large helical device plasmas
Authors: Mase Atsushi , Yokota Yuya , Uchida Kazuyuki , Kogi Yuichiro , Ito Naoki , Tokuzawa Tokihiko , Kawahata Kazuo , Tanaka Kenji , Nagayama Yoshio , Hojo Hitoshi
Published: October 2006

An ultrashort-pulse reflectometer (USPR) has been applied to the large helical device plasmas in National Institute for Fusion Science for edge density profile measurement. Remote control system using super science information network has been introduced to the USPR system. The remote console at Kyushu University having graphical user interface is prepared to control the instruments of the USPR via the general-purpose interface bus. The operations such as the adjustment of supply voltage fed to amplifiers and the frequency doubler, timing control of the impulse, data acquisition, and monitoring can be performed from the remote site. The position of transmitter and receiver antennas can also be controlled remotely in order to observe the cutoff layer depending on various plasma conditions. The directly recorded signal by a sampling scope is analyzed and reconstructed by means of the signal record analysis method.
Electrical conductance and breakdown in individual CNx multiwalled nanotubes
Authors: Burch Hilary J. , Davies Julia A. , Brown Elisabetta , Hao Ling , Contera Sonia Antoranz , Grobert Nicole , Ryan J. F.
Published: October 2006

Doping of carbon nanotubes with nitrogen during growth strongly modifies their electronic structure through n-type doping. This provides the possibility of producing nanotubes with high conductances, independent of tube chirality. To date, electrical measurements on individual nitrogen-doped multiwalled nanotubes (CNx MWNTs) have reported surprisingly low conductances (∼0.01G0). Here the authors present high conductance (1.0±0.3G0) measurements at low bias for individual CNx MWNTs. Conductance increases linearly with voltage at a rate of 0.7±0.2G0∕V until the threshold for electrical breakdown is reached. Discrete current steps of 20±10μA are then observed.
High‐resolution optical coherence tomography as a non‐destructive monitoring tool for the engineering of skin equivalents
Authors: Spöler F. , Först M. , Marquardt Y. , Hoeller D. , Kurz H. , Merk H. , Abuzahra F.
Published: October 2006

Background: Three dimensional skin equivalents are widely used in dermatopharmacological and toxicological studies and as autologous transplants in wound healing. In pharmacology, there is tremendous need for monitoring the response of engineered skin equivalents to external treatment. Transplantation of skin equivalents for wound healing requires careful verification of their quality prior to transplantation. Optical coherence tomography (OCT) is a non‐contact, non‐destructive imaging technique for living tissues offering the potential to fulfill these needs. This work presents an analysis of OCT for high‐resolution monitoring of skin equivalents at different stages during the culture process.

Methods: We developed a high‐resolution OCT imaging setup based on a commercially available OCT system. A broadband femtosecond laser light source replaces the original superluminescence diode. Tomograms of living skin equivalents were recorded with an axial resolution of 3 μm and correlated with histology and immunofluorescence images. Comparison with standard low‐resolution OCT is presented to emphasize the advantages of high‐resolution OCT for this application.

Results: OCT is particularly able to distinguish between different layers of skin equivalents including stratum corneum, epidermal and dermal layer as well as the basement membrane zone. The high‐resolution OCT scans correlate closely with two key benchmarks, histology and immunofluorescence imaging.

Conclusions: This study clearly demonstrates the benefits of high‐resolution OCT for identifying living tissue structure and morphology. Compared with the current gold standard histology, OCT offers non‐destructive tissue imaging, enabling high‐resolution evaluation of living tissue morphology and structure as it evolves.
Assessing the Importance of Factors Determining Decision‐Making by Actors Involved in Innovation Processes
Authors: Heerkens Hans
Published: October 2006

Innovations can be seen as chains of non‐routine decisions. With each decision, the innovator has to assess how important the various decision attributes are. Because the decisions are non‐routine, innovators cannot fall back on judgements of past importance. Most decision support methods elicit importance judgements but do not help innovators or other decision‐makers with the mental processes leading to the judgment. The ‘importance assessment process’ can be divided into seven phases (such as (sub‐)attribute processing and various forms of weighting). The phase ‘(sub)‐attribute processing’ is the most important phase in terms of effort devoted to it, and the most obvious pitfalls that prevent valid importance assessments appear in this phase. This article describes some of these pitfalls. A few simple instruments may provide better‐founded importance judgements that can be better communicated to other actors involved in innovation processes.
FREE NUCLEOTIDES IN NERVE CELLS EXTRACTION
Authors: Brattgård S. ‐O. , Løvtrup‐Rein H. , Moss M. L.
Published: October 2006

Several means for inhibiting degradation of free ribonucleotides in brain tissue have been investigated, along with extraction agents that minimize subsequent breakdown. The conditions selected are suitable for isolation of single nerve cells without appreciable loss in triphosphate levels, and thus, provide means for turnover studies at the cellular level by isotope incorporation in the free nucleotides.
CHANGES IN MEMORY, ELECTROPHYSIOLOGY, NEUROCHEMISTRY AND NEURONAL ULTRA‐STRUCTURE AFTER DEUTERON IRRADIATION OF THE BRAIN IN C57B1/10 MICE
Authors: Ordy J. M. , Samorajski T. , Horrocks L. A. , Zeman W. , Curtis H. J.
Published: October 2006

Abstract— Changes in memory, electrocorticograms (ECoG), protein, DNA, RNA, neurotransmitters, enzyme activity and neuronal ultrastructure were examined after deuteron irradiationof the brain in C57B1/10 mice. Twenty animals served as sham‐irradiated controls, while three irradiated groups received a dose of either 500, 5000 or 10,000 rads covering an area of 9 × 5 mm over the dorsal surface of the brain and extending to a depth of 2 mm from the skull. The 10,000 rad group differed significantly in retention of spontaneous locomotor performance and dark maze exploration during a 16‐month post‐irradiation period. Desynchronization with an overall amplitude reduction of both spontaneous and light evoked ECoG was observed in the 10,000 rad group. There was a dose‐dependent decrease in protein, DNA and RNA content but not in their concentrations. Brain irradiation resulted in a significant change in content as well as concentration of 5‐HT and in acetylcholinesterase activity both per brain and per gram fresh weight. Morphologically, there was a significant reduction in brain and pituitary weight. Histochemical observations indicated a uniform and dose‐dependent reduction in vascular alkaline phosphatase activity and a selective decrease in staining for cellular DNA and RNA in different regions of the irradiated tissue of the brain. Electron microscopic comparisons of nuclear and cytoplasmic changes indicated serration of some nuclear membranes in the 10,000 rad group, accumulation of glycogen, numerous phagocytes and formation of multi‐lamellar intraneuronal membranes. Prominent synaptic changes were not observed in the remaining neurons within the irradiated tissue of the brain. From the multidisciplinary comparisons it was concluded that deuteron irradiation of the CNS can be used as another approach for relating changes in such unique functions as learning and memory to subcellular and cellular changes in specific regions of the brain.
THE EFFECT OF BILIRUBIN ON THE ENERGY METABOLISM OF BRAIN MITOCHONDRIA
Authors: Vogt Molly T. , Basford R. E.
Published: October 2006

Abstract— Unconjugated bilirubin caused uncoupling of oxidative phosphorylation in brain mitochondria prepared from mature or weanling rats. Human serum albumin in an amount sufficient to bind 100 per cent of the added bilirubin was able to protect the mitochondria from the inhibitory effects of bilirubin. Bilirubin inhibited both the endogenous and DNP‐activated ATPase activities but had no effect upon the Mg2+‐stimulated ATPase; albumin prevented the inhibition.
ENZYMIC CONVERSION OF URIDINE NUCLEOTIDE TO CYTIDINE NUCLEOTIDE BY RAT BRAIN
Authors: Dawson D. M.
Published: October 2006

—After in vivo administration of [14C]uridine monophosphate to rats, radioactivity appears in cytidine nucleotides at comparable rates in the brain and the liver.

An in vitro assay, on the soluble fraction of rat brain showed that the enzyme required for amination of uridine nucleotide to cytidine nucleotide occurs in the brain.
CHOLINERGIC NERVE ENDINGS IN OCTOPUS BRAIN
Authors: Florey E. , Winesdorfer J.
Published: October 2006

—Optic lobes of the brains of Octopus dofleini werehomogenized hasaline–sucrose medium and subjected to differential and density gradient centrifugation. The fractions and subfractions thus obtained were analysed for acetylcholine (ACh) (bioassay) and protein content and were subjected to electronmicroscopy. Bound ACh was associated with particulate fractions, and a large portion of it could be recovered in subfractions that contained predominantly nerve endings.

Expressed in terms of amount of ACh per mg protein, the ACh content of the nerve ending fractions was nearly 100 times greater than that of corresponding fractions previously obtained by others from mammalian brain. Calculations show that this was the minimal amount of ACh to be expected if the isolated nerve endings were predominantly cholinergic. Octopus brain tissue is in therefore very promising for future studies on ACh metabolism and compartmentation cholinergic nerve endings.
INFLUENCE OF AGE IN THE INCORPORATION OF [14C]GLYCINE INTO ISOLATED RAT NERVE SEGMENTS IN VITRO
Authors: Matheson D. F.
Published: October 2006

—(1) Sciatic nerves of young rats have been shown to incorporate [14C]glycine in vitro into the protein fraction at a higher rate than nerves from adult rats under the same conditions.

(2) Whilst there is little change in the DNA content of the sciatic nerve of rats with age, there is a is noticeable decline in the RNA content with age.

(3) There a linear relationship between the specific activity of the protein fraction and the RNA content of the sciatic nerve under in vitro conditions.

(4) There is a decline in the specific activity of the protein fraction with age when expressed against DNA.

(5) A linear relationship exists between the logarithm of the specific activity and the length of the femur.
CEREBRAL AMINO ACIDS AND LIPIDS IN DRUG‐INDUCED STATUS EPILEPTICUS*
Authors: Whisler K. E. , Tews J. K. , Stone W. E.
Published: October 2006

—Dogs were given repeated doses of pentylenetetrazol to maintain a condition of status epilepticus for periods of 30–40 min. Analyses of cerebral tissue frozen in situ showed significant increases in alanine, arginine, γ‐aminobutyric acid, glycine, histidine, leucine, lysine, phenylalanine, serine, tyrosine, and valine. Decreases occurred in the glutamic and aspartic acid levels. Other measured amino compounds were unchanged. Ammonia was increased, but not more than occurs in seizures of brief duration. A large decrease was noted in the ganglioside fraction, and a decrease also in a fraction containing the lecithins and sphingomyelins. The cephalin, cerebroside–sulphatide, and cholesterol fractions were not affected.

Similar repetitive seizures induced by bemegride and continuing for shorter periods (5–9 min) brought about less extensive changes. Glutamic acid was increased, in contrast to the pentylenetetrazol effect, and the apparent decrease in aspartic acid was not statistically significant. Increases were noted in alanine, γ‐aminobutyric acid, lysine, and ammonia. The ganglioside and lecithin‐sphingomyelin fractions were decreased.
THE INFLUENCE OF HIGH PHENYLALANINE AND TYROSINE ON THE CONCENTRATIONS OF ESSENTIAL AMINO ACIDS IN BRAIN
Authors: McKean C. M. , Boggs D. E. , Peterson N. A.
Published: October 2006

—High circulating levels of phenylalanine caused depletions of threonine, valine, methionine, isoleucine, leucine, histidine, tryptophan, and tyrosine in immature and adult rat brains. The branched‐chain amino acids were most affected. Their reductions ranged between 38–64 per cent of control values when phenylalanine was administered either parenterally or in the diet. The pattern of cerebral amino acid depletions found in phenylalanine‐injected infant rats was similar to that of the adults. Phenylalanine loading caused depletions in serum amino acid levels in adult rats, but in infant rats the serum levels were either unchanged or somewhat elevated.

Tyrosine, when administered to adult rats either parenterally or via the diet, caused cerebral depletions in essential amino acids, but the depletions were not as striking as with phenylalanine.

In both the infant and adult rat, brain‐blood ratios of most of the essential amino acids were significantly reduced by phenylalanine loading.
HISTOCHEMISTRY OF RAT BRAIN STEM MONOAMINE OXIDASE DURING MATURATION
Authors: Robinson N.
Published: October 2006

—Monoamine oxidase (MAO) activity in the nuclei and tracts of the medulla and pons of the rat from birth to 90 days is reported.

Prominent MAO activity was present in the locus coeruleus and nucleus ambiguus at birth. At 5 days a weak reaction localized mainly within the neuropil and glia cells was detected in several other nuclei. By 10 days all nuclei were identified with MAO activity varying from weak to intense, the activity showing further increases at 15 and 20 days. Staining in nerve fibres was negligible at 5 days but increased rapidly to 15 days in some tracts when the characteristic beading pattern was distinct. At 30 days differentiation in intensity of MAO activity between the nuclei diminished and no increase was apparent after 55 days.

The results are compared with the distribution of brain stem acetylcholinesterase during maturation and also with regions specific in catecholamine or serotonin content in the adult rat brain stem.

This and an earlier study on the cerebrum suggest that MAO is another component of the brain that falls into the caudal‐rostral concept of biochemical maturation and that it fits into a group of enzymes exhibiting a similar pattern of increase in activity during development.
HYDRAZINOPROPIONIC ACID: A NEW INHIBITOR OF AMINOBUTYRATE TRANSAMINASE AND GLUTAMATE DECARBOXYLASEI
Authors: van Gelder N. M.
Published: October 2006

Abstract— This paper deals with the synthesis of 3‐pyrazolidone and the biochemical action of hydrazinopropionic acid. The latter compound is formed upon alkaline hydrolysis of 3‐pyrazolidone.

Hydrazinopropionic acid was found in vitro to be a very potent inhibitor of bacterial aminobutyrate transaminase as well as of aminobutyrate transaminase and glutamate decarboxylase from mouse brain. This inhibition was shown to occur despite the presence of high concentrations of pyridoxal phosphate in the incubation media.

Injections of 20 mg hydrazinopropionic acid/kg into mice resulted in complete inhibition of aminobutyrate transaminase in brain and approximately 20 per cent inactivation of glutamate decarboxylase. This inhibition could not be prevented or antagonized by administration of pyridoxine to the animals. Addition of pyridoxal phosphate to homogenates of brain from animals treated with hydrazinopropionic acid also failed to reactivate the enzymes.

The tentative conclusion reached from these results is that hydrazinopropionic acid has inhibitory action because of its close similarity to GABA with respect to molecular size, structural configuration and molecular charge distribution. This can be demonstrated by comparing a Dreiding model of hydrazinopropionic acid with that representing GABA.
CHOLESTERYL ESTERS OF THE GLIOBLASTOMA*
Authors: White H. B. , Smith R. R.
Published: October 2006

Abstract The sterol ester fraction in the human glioblastoma was isolated and characterized. Cholesterol was identified as the constituent sterol. Contained in the complex mixture of fatty acids were members with 0‐4 double bonds and 14‐28 carbon atoms. About 1/4 of the acids were polyunsaturated. Long chain members (C20 and above) composed 1/3 of the mixture. The results suggest that the sterol ester component in the glioblastoma does not derive from blood plasma.
THE EFFECT OF SLOW WAVE SLEEP AND REM SLEEP ON REGIONAL CEREBRAL BLOOD FLOW IN CATS*
Authors: Revich M. , Isaacs G. , Evarts E. , Kety S.
Published: October 2006

Abstract Regional cerebral blood flow was measured by means of an autoradiographic technique in unanaesthetized, unrestrained cats during wakefulness, slow wave sleep (S‐SW), and rapid eye movement sleep (S‐REM). The electrocorticogram, electro‐oculogram, and electromyogram from the posterior neck muscles were continuously recorded. All operative procedures were completed at least four days prior to the experiment. Arterial blood samples were obtained immediately prior to the regional cerebral blood flow determination and analysed for PCO2, PO2, pH, and haematocrit. There were no significant differences in these parameters among the three groups.

During S‐REM there was a significant increase in flow in all twenty‐five regions measured which varied from 62 per cent in the cerebellar white matter and sensory‐motor cortex to 173 per cent in the cochlear nuclei. During S‐SW a significant increase in flow occurred in only ten of the twenty‐five regions, and these changes were smaller in magnitude, varying from 26 per cent in the association cortex to 68 per cent in the superior olive. It is postulated that local changes in cerebral metabolism account for the regional cerebral blood flow changes demonstrated.
OXIDATIVE PHOSPHORYLATION IN MITOCHONDRIA OF DEVELOPING RAT BRAIN
Authors: Milstein J. M. , White J. G. , Swaiman K. F.
Published: October 2006

Abstract—

Oxygen uptake, ADP/O ratios and respiratory control ratios (RCR) were studied by oxygen electrode techniques in mitochondria prepared from developing rat brain.

Oxygen consumption, ADP/O ratios and RCR based on mitochondrial protein concentration increased with maturation. Of the substrates employed, succinate supported oxygen uptake best and malate poorest.

The addition of exogenous NAD to the mitochondrial preparation had no effect on rate of oxygen uptake.

Lack of change in ADP/O ratio in the presence of glucose, a tricarboxylic acid cycle intermediate (α‐oxoglutarate), and ATP leads us to believe that there is no significant hexokinase activity in this preparation.
METABOLISM OF SPECIFICALLY LABELLED GLUCOSE BY EXPLANTS OF NEWBORN MOUSE CEREBELLUM*
Authors: Hoskin F. C. G. , Allerand C. Dominique
Published: October 2006

Abstract— Newborn mouse cerebellum developing in culture metabolizes specifically labelled glucose to labelled carbon dioxide at a high rate and in a manner indicating virtually no participation of the pentose phosphate pathway. Furthermore, there appears to be no shift to this alternate metabolic route prior to or during myelin formation, or during the later stage of myelin maintenance and neuronal maturation. The equal incorporation of specifically labelled glucose into phospholipids further substantiates these conclusions. The higher rate of metabolism of this material than of the more conventional tissue slices makes brain tissue developing in culture a most promising material for neurochemical studies.
DEVELOPMENTAL CHANGES IN MOUSE BRAIN: WEIGHT, WATER CONTENT AND FREE AMINO ACIDS
Authors: Agrawal H. C. , Davis J. M. , Himwich W. A.
Published: October 2006

Abstract— —Glutamic acid, glutamine, GABA and aspartic acid exhibited postnatal increases in the developing mouse brain at the same time that the other amino acids, both essential and non‐essential, of the pool decreased. The most significant decreases were observed in the concentrations of taurine, phosphoethanolamine, glycine and alanine. The period of rapid accumulation of the members of the glutamic acid family in the mouse brain was concurrent with dramatic increases and decreases in brain weight and water content, respectively.
WALLERIAN DEGENERATION IN RABBIT TIBIAL NERVE: CHANGES IN AMOUNTS OF THE S‐100 PROTEIN1
Authors: Perez V. J. , Moore B. W.
Published: October 2006

Abstract— —A soluble protein (S‐100) which is unique to the nervous system was measured in rabbit tibial nerve at 0, 3, 7, 14, 21, and 28 days of degeneration. Amounts of S‐100 in the degenerated peripheral segment of the transected nerve fell progressively during degeneration to 2 per cent of that measured in the corresponding portion of nerve taken from control rabbits 28 days postoperatively. Total soluble proteins increased 42 per cent during this time. Levels of S‐100 and total soluble proteins remained unchanged in non‐degenerated nerve segments from experimental and control rabbits. Correlations of amounts of S‐100 measured in the study reported here with cellular changes demonstrated by other investigators to characterize Wallerian degeneration in peripheral nerve suggest that the S‐100 protein is localized primarily in axons rather than in Schwann cells or myelin.
SYNTHESIS OF ADENOSINE TRIPHOSPHATE BY MYELIN OF SPINAL NERVES OF RABBIT1
Authors: Miani N. , Cavallotti C. , Caniglia A.
Published: October 2006

Abstract—

The myelin fraction isolated by isopycnic gradient centrifugation from rabbit nerve is able to synthesize ATP at substrate level through the Embden‐Meyerhof pathway. Suitable conditions are described to preserve the association of glycolytic enzymes with isolated myelin.

Except for phosphofructokinase and ketose‐1‐phosphate aldolase, all the remaining glycolytic enzymes are present in the myelin. A wide divergence was found in the firmness of the association of individual glycolytic enzymes with myelin under the condition of isolation; some, like glucosephosphate isomerase and glyceraldehydephosphate dehydrogenase were retained in high percentage (about 60 per cent of the activity of the homogenate is myelin‐bound); others were weakly bound (no more than 7–6 percent of the lactate dehydrogenase activity of the homogenate is myelin‐bound).

By using glyceraldehyde‐3‐phosphate as substrate for glycolysis, about 25 per cent of the total glycolytic activity of rabbit‐nerve homogenate is associated with the myelin.

Glucosephosphate isomerase and lactate dehydrogenase may be extracted from and readily recombined with the myelin.
RELEASE OF γ‐AMINOBUTYRIC ACID INTO THE FOURTH VENTRICLE INDUCED BY STIMULATION OF THE CAT'S CEREBELLUM
Authors: Obata K. , Takeda K.
Published: October 2006

Abstract— The fourth ventricle of the cat was perfused and the release of γ‐aminobutyric acid (GABA) into the perfusate was measured. GABA was released at a rate of 6·69 × 10−10 moles/min and increased about three times during cerebellar cortical stimulation at 200/sec. It is suggested that GABA is released from axon terminals of Purkinje cells in cerebellar subcortical nuclei.
SYNTHESIS OF SULPHATIDE‐CONTAINING LIPOPROTEINS IN RAT BRAIN1
Authors: Herschkowitz N. , McKhann G. M. , Saxena S. , Shooter E. M. , Herndon R.
Published: October 2006

Abstract—

Puromycin inhibits [14C]leucine Hincorporation into brain proteins, but has no effect on the incorporation of [35S]sulphate into sulphatide. These effects of puromycin are observed not only with the proteins and sulphatide of whole brain, but also with the protein and sulphatide portion of water‐soluble lipoprotein complexes.

Microsomes can be separated into three subfractions which differ chemically, morphologically and metabolically. Protein synthesis and sulphatide synthesis are located in different submicrosomal fractions.

The addition of water‐soluble brain proteins to the incubation medium causes release of newly synthesized [35S]sulphatide and formation of soluble sulphatide protein complexes. One acceptor protein is identified as the lipoprotein previously shown to bind [35S]sulphatide in vivo (Herschkowitz, McKhann, Saxena and Shooter, 1968b).

These results suggest that protein and sulphatide synthesis can function independently and that association of newly synthesized lipid to preformed protein is possible.
VERÄNDERUNGEN DER AMINOSÄUREKONZENTRATIONEN IM RATTENHIRN BEI VERRINGERUNG DER K+‐ZUFUHR IN VIVO
Authors: Gründig E. , Hanbauer I.
Published: October 2006

Zusammenfassung—

Bei Verfütterung des Kationenaustauschers Resonium A an Ratten konnte im ZNS keine Abnahme der K+‐Konzentration gefunden werden wie etwa im Lebergewebe. Hingegen stieg der K+‐Gehalt in ‘Cortex’ und ‘Striatum’ leicht an.

Gleichzeitig erhöhte sich die Konzentration der freien Aminosäuren in ‘Cortex’, ‘Striatum’, ‘Thalamus’ und Cerebellum—für Glutaminsäure nur etwa um 70–80 Prozent, die der meisten übrigen Aminosäuren auf das 2–3 fache: am stärksten war der Anstieg von GABA und Glycin.

K+‐Restitution durch K+‐reiche Kost führte nach 7 Tagen zur Normalisierung des Aminosäuren‐Gehaltes in ‘Cortex’ und Cerebellum; in ‘Striatum’ und ‘Thalamus’ konnte ein Overshoot beobachtet werden.

Das Analysenverfahren zur Bestimmung der Konzentrationen freier Aminosäuren im Hirngewebe wird diskutiert.
METABOLISM OF THE PHOSPHOINOSITIDES IN GUINEA‐PIG BRAIN SYNAPTOSOMES
Authors: Harwood J. L. , Hawthorne J. N.
Published: October 2006

Abstract— The subcellular distribution of a number of enzymes concerned with inositol lipid metabolism has been studied in sub‐fractions of disrupted guinea‐pig brain synaptosomes. The enzymes were CDP‐diglyceride: inositol phosphatidate transferase, phospha‐tidylinositol kinase, diphosphoinositide kinase, diphosphoinositide phosphomonoesterase and diphosphoinositide diesterase. The distribution of phosphatidylinositol kinase in sub‐fractions from water‐treated synaptosomes was compared with that of other plasma membrane enzymes. After partial solubilization of synaptosomes by Triton X‐100 the activities of phosphatidylinositol kinase and several other enzymes were examined.

Distribution of phosphatidylinositol kinase closely resembled that of acetylcholinesterase in sub‐fractions of synaptosomes. Both enzymes appeared to be localised in the outer membrane of the synaptosome. CDP‐diglyceride: inositol phosphatidate transferase was present in all types of synaptosomal membrane. All three enzymes concerned with diphosphoinositide metabolism were found in the cytoplasm of the synaptosome.
EFFECTS OF ANTIEPILEPTIC DRUGS ON BRAIN ENERGY RESERVES DURING CONVULSIONS1
Authors: King Lucy J. , Carl Juanita
Published: October 2006

Abstract—

Cerebral cortical ATP, P‐creatine, glucose, and lactate were measured 6 sec after 1 sec of 150/sec rectangular pulses, at 0,20 v, 40 v, 60 v, 80 v, or 100 v, applied to the heads of intact mice which had been given either no drug, phenobarbitone (25 mg/kg), trimethadione (600 mg/kg), or diphenylhydantoin (40 mg/kg), intraperitoneally. In general, regardless of stimulus strength or drug used, animals which exhibited maximal (tonic‐clonic) convulsions showed similar striking decreases in brain P‐creatine, decreases in ATP and glucose, and increases in lactate. On the other hand, in animals which exhibited less than maximal clinical response, there was little or no change in these metabolites. An exception was the case of diphenylhydantoin. Tonic‐clonic seizures did not occur after diphenylhydantoin administration, even with 100 v stimuli, but substrate changes at this voltage were, nevertheless, similar to those observed in brains of other mice undergoing maximal convulsions.
STUDIES OF AMINES IN THE STRIATUM IN MONKEYS WITH NIGRAL LESIONS
Authors: Goldstein M. , Anagnoste B. , Battista A. F. , Owen W. S. , Nakatani S.
Published: October 2006

Abstract—

The effects of ventromedial tegmental lesions on the biosynthesis and disposition of biogenic amines in the striatum of monkeys were investigated. The concentrations of endogenous dopamine and of the intraventricularly injected [3H]dopamine were distinctly lower in the striatum on the lesion side than on the intact side.

The storage of [3H]dopamine in the caudate nucleus was impaired to a much greater extent than the storage of the newly synthesized [3H]norepinephrine.

The concentrations of endogenous serotonin and of the intraventricularly injected [14C]serotonin were lower in the striatum on the lesion side than on the intact side. However following MAO inhibition, the concentration of [14C]serotonin did not differ significantly on the two sides of the caudate nucleus.

The in vivo biosynthesis of dopamine from tyrosine was significantly reduced in the striatum on the lesion side. Tyrosine hydroxylase and DOPA decarboxylase activities were decreased on the lesion side of the striatum as compared with the intact side. Thus, the ventromedial tegmental lesions affect the storage and the synthesis of dopamine and serotonin in the ipsilateral striatum.
URIDINE PHOSPHORYLASE FROM RAT BRAIN: CHARACTERISTICS AND DEVELOPMENTAL COURSE
Authors: Guroff G. , Rhoads Carol A.
Published: October 2006

—Uridine phosphorylase (uridine: orthophosphate ribosyltransferase; EC 2.4.2.3) from rat brain was purified and its properties were studied. The enzyme resembled preparations made from other mammalian sources. Its pH optimum was between 7·6 and 8·0. An examination of its action on various substrates showed rates of reaction in the order: uridine > deoxyuridine > thymidine > cytidine. The enzyme showed a requirement for phosphate which could also be satisfied by arsenate. The activity of the enzyme was protected from heat inactivation by uridine and by phosphate. In brain and liver the activity of the enzyme increased five‐ to ten‐fold between 10 and 20 days of life. Injections of cortisol or of uridine did not increase the enzymic activity.
A METHOD FOR THE STUDY OF CHOLESTEROL BIOSYNTHESIS IN THE CENTRAL NERVOUS SYSTEM
Authors: Chevallier F. , Gautheron C.
Published: October 2006

Abstract—

After intraperitoneal injection, there is negligible incorporation of [2‐14C]‐mevalonic lactone into the CNS of the adult rat.

Mevalonic lactone injected into the CSF is quickly transferred to blood.

Mevalonic lactone injected in the cistema magna or the lateral ventricle of the brain does not diffuse readily into the whole CSF. Spinal cord cholesterol is most heavily labelled after intracisternal injection, as is brain cholesterol after intraventricular administration.

After intraventricular perfusion, the diffusion of mevalonic lactone into the ventricle opposite the side of the injection is increased when the rate of perfusion is doubled from 5 to 10 μ1/hr. After injection, optimal homogeneity is obtained if a large volume (70μl) is administered.

An increase in the volume of injection from 70 μl to 130μl does not alter the distribution of activity between the left and right ventricles, nor does it increase the diffusion of mevalonic lactone from ventricle to spinal cord CSF.

The mean yield of mevalonic lactone incorporation into brain cholesterol is much higher after injection than after perfusion of precursor into the lateral cerebral ventricle.
THE EFFECT OF PHENYLALANINE AND ITS METABOLITES ON GLUCOSE UTILIZATION IN DEVELOPING BRAIN
Authors: Swaiman K. F. , Lemieux B.
Published: October 2006

Abstract— High concentrations of phenylalanine, o‐tyrosine, and phenylpyruvic acid do not modify the ability of immature rabbit brain to utilize glucose for support of respiration or for oxidative decarboxylation.
ISOLATION AND IDENTIFICATION OF α‐ASPARTYL‐SERINE, ALANYLPHENYLALANINE AND ISOLEUCYLLEUCINE FROM CALF BRAIN STEM
Authors: Versteeg D. H. G , Witter A
Published: October 2006

Abstract— A reproducible extraction and fractionation scheme for the isolation of peptides from nervous tissue is described. The low molecular weight fraction, obtained by this procedure from calf brain stem tissue, was further investigated. The presence of N‐acetyl‐aspartic acid, N‐acetyl‐α‐aspartylglutamic acid and pyrrolidone‐2‐carboxylic acid was confirmed. The occurrence of minor quantities of glutamylpeptides, identical with or related to known γ‐glutamyldipeptides and glutathione, was indicated.

Three hitherto unknown dipeptides α‐aspartylserine, alanylphenylalanine and isoleucylleucine were identified. Mass spectrometry was used in the final structure analysis.
PROPERTIES OF RAT BRAIN NAD‐KINASE
Authors: Fernandes M
Published: October 2006

Abstract— NAD‐kinase was purified from rat brain acetone powder according to the method of Wang and Kaplan (1954). The acetate buffer supernatant showed only very low specific activity but was largely free of the factors that interfere with the enzyme assay. The Michaelis constants for both substrates were determined, the values were 0·5 mm for NAD and 4·0 mm for ATP. The optimal pH was 7·4 in tris‐HCl buffer and the highest NAD‐kinase activity was observed in the hyaloplasm fraction. NADH2 inhibited the enzyme whereas NADPH2 did not. Finally, the reversible inhibition of SH‐binding compounds is described and the observed properties of rat brain NAD‐kinase compared with the properties of NADP synthesizing enzymes from pigeon liver and rat liver.
FATTY ACID COMPOSITION OF CEREBROSIDES IN MICROSOMES AND MYELIN OF MOUSE BRAIN
Authors: Blass J. P
Published: October 2006

Abstract— The fatty acid composition of cerebrosides isolated from myelin and from light and heavy microsomes of adult mouse brain was determined. 2‐Hydroxy fatty acids represented 80 per cent of the fatty acids in myelin cerebrosides and approximately 55 per cent of the fatty acids in both light and heavy microsomes. In myelin, the majority of the fatty acids, both normal and hydroxy, were of chain length > C‐20; in microsomes, shorter chain acids (C‐16 to C‐20) predominated.
GLYCOPROTEINS OF SUBMAXILLARY SALIVA OF THE CAT: DIFFERENCES IN COMPOSITION PRODUCED BY SYMPATHETIC AND PARASYMPATHETIC NERVE STIMULATION1
Authors: Dische Z , Kahn N , Rothschild C , Danilchenko A , Licking J , Wang S. C
Published: October 2006

Abstract— Saliva samples were obtained from the cannulated submaxillary ducts of the cat during stimulation of the peripheral cut end(s) of (1) the cervical sympathetic nerve, (2) the chordalingual (parasympathetic) nerve and (3) both nerves at the same time. In nine experiments the ratios of neuraminic acid to fucose and to hexosamine were consistently 2·5–4 times higher in saliva evoked by sympathetic nerve stimulation than in that produced by parasympathetic stimulation. This was not attributable to differences in the rate of synthesis of the carbohydrate of the glycoproteins or in salivary flow rate. The presence of glycolipids and blood glycoproteins was excluded. Saliva produced by stimulation of the sympathetic and parasympathetic nerves each showed a single, but different, peak after ultracentrifugation in 0·1 m‐NaCl with 0·01 m‐phosphate buffer (pH 7·4). The S20, w of the former was 6·5 and of the latter, 39. Both peaks were demonstrable in saliva produced when both nerves were stimulated at the same time.
DAS MEDIKAMENTÖSE PARKINSONOID BEI DER RATTE ALS MODELL FÜR BIOCHEMISCHE UNTERSUCHUNGEN DES PARKINSONSYNDROMS BRAIN AMINOACIDS IN PHENOTHIAZIN‐INDUCED PARKINSONISM DRUG‐INDUCED PARKINSONISM IN THE RAT—A MODEL FOR BIOCHEMICAL INVESTIGATIONS OF THE PARKINSON‐SYNDROME
Authors: Gründig E. , Hanbauer I.
Published: October 2006

Zusammenfassung Durch kombinierte Gaben von Majeptil2 und Randolectil3 wurde bei Ratten ein extrapyramidales Syndrom ausgelöst, in dessen Verlauf die Konzentrationen der‘Inhibitor’‐Aminosäuren Glycin und γ‐Aminobuttersäure in den von uns untersuchten Hirnregionen (‘Cortex’, ‘Striatum’, ‘Thalamus’ und Cerebellum) anstiegen, die der Glutaminsäure aber abnahm.
BRAIN LIPID MODIFICATIONS INDUCED BY ESSENTIAL FATTY ACID DEFICIENCY IN GROWING MALE AND FEMALE RATS
Authors: Galli C. , White H. B. , Paoletti R.
Published: October 2006

—Essential fatty acid (EFA) deficiency initiated in rats prior to birth and continued for one year affects brain lipids to an extent which differs in the two sexes. It was found that:

(1) Brain weight and lipid content were decreased in deficient conditions, especially in males.

(2) Total phospholipids were present in lower concentrations, particularly in the deficient male brain, while the percentage of the major phospholipid classes‐ethanolamine phosphoglyceride (EPG), choline phosphoglyceride (CPG) and serine phosphoglyceride (SPG) did not change.

(3) Brain EPG, CPG and SPG had distinctive fatty acid patterns differing greatly in polyunsaturation content. PE acids of control females had elevated monoenes and reduced saturates in comparison with control males. This sex difference was lost in the deficient animals.

(4) Polyunsaturated fatty acids of EPG, CPG and SPG were markedly changed in animals lacking dietary linoleic acid. Trienoic (C20 and C22) and docosapentaenoic acids were greatly increased, whereas arachidonic, docosatetraenoic and docosahexaenoic acids were much decreased.

(5) In spite of the changes in fatty acid composition each of the three phospholipid classes maintained its particular level of unsaturation during EFA deficiency.

(6) EPG aldehydes did not change appreciably in deficient conditions.
SPHINGOLIPIDS OF DEVELOPING HUMAN CENTRAL NERVOUS TISSUE: CHANGES IN COMPOSITION OF SPHINGOSINE BASES12
Authors: Isaacson Elizabeth , Moscatelli Ezio. A.
Published: October 2006

—Developmental changes in composition of sphingosine bases of cerebrosides, sulphatides and sphingomyelins were investigated in samples from brain stem or corpus callosum from premature infants and patients aged 14 months, 39 and 59 years who died of non‐neurological causes. Since insufficient material was obtainable from the premature brains, sulphatides were studied only in older cases. Individual sphingolipids were isolated by combinations of column chromatography and TLC, and were examined for purity by analytical TLC. Sphingosine bases were released by acid‐catalysed methanolysis, and analysed as aldehydes by GLC. Effectiveness and limitations of methods used for analyses of sphingosine bases were evaluated.

In contrast to adult sphingolipids in which approximately 95 per cent of the sphingosine bases was 18: sphingosine, as much as 10 per cent of the total was 18: dihydrosphingosine in immature sphingolipids. A compound tentatively identified as 20: sphingosine was present in foetal, infant and adult sphingomyelin at 5, 3 and 1 per cent of the total, respectively. Composition of sphingosine bases of non‐ganglioside sphingolipids in human brain varies with age, presumably in a complex manner.
THE EFFECT OF N‐METHYL‐4‐PIPERIDYL‐DIPHENYL GLYCOLATE ON THE INCORPORATION OF 32P INTO PHOSPHOLIPIDS FROM RAT BRAIN CORTEX SLICES AND ITS SUBCELLULAR LOCALIZATION
Authors: Heilbronn E. , Widlund L.
Published: October 2006

—N‐Methy‐4‐piperidy1‐diphenyl glycolate (N‐methy1‐4‐piperidy1 benzilate), an anticholinergic drug, was shown to stimulate 32P‐incorporation into total phospholipids of rat brain cortex slices. Analysis of the total phospholipids showed stimulation in phosphatidic acid, phosphatidylinositol and phosphatidylethanolamine. Stimulated 32P‐incorpora‐tion was accompanied by a decrease in the Qo2 (μ1 O2/mg dry tissue) value. The effects of the drug were compared with those of some other CNS‐active drugs known to interfere with the ACh content of brain; tremorine, oxotremorine and atropine; and in the presence of eserine, with that of the neurotransmitter acetylcholine.

Increase of the outer K+‐concentration resulted in increased Qo2 and 32P‐incorporation into the slices. The effect of the glycolate and perhaps that of atropine tended to increase in this medium. Subcellular fractionation of slices showed that the glycolate stimulated 32P‐incorporation occurred mainly in the nerve end fraction. The total amount of the individual phospholipids was not changed, but the specific activity had significantly increased in phosphatidic acid and phosphatidylinositol. The possibility that glycolate‐induced stimulated 32P‐incorporation into nerve end phospholipids is due to increased glycolysis is discussed.
GLUTAMATE METABOLISM IN OCTOPUS BRAIN IN VIVO;ABSENCE OF A WAELSCH EFFECT
Authors: Rose S. P. R. , Cory H. Therese
Published: October 2006

Abstract— The metabolism of [U‐14C]glutamate was followed in vivo in the octopus Eledone cirrhosa following intracranial injection, and compared with that in the mammalian brain.

By contrast with the rat brain, the specific activity of glutamine recovered from Eledone optic and vertical lobes was lower than that of glutamate at short time intervals after injection. Thus the Waelsch effect was not apparent in this species. Again, in contrast with the rat brain, radioactivity could be found in alanine but not in GABA following [U‐14C]glutamate injection. This was compatible with observations made previously in vitro.

The significance of these intraspecies differences in metabolism and compartmentation is discussed.
THE INTERACTION BETWEEN PERIPHERAL NERVE POLYANIONS AND ALCIAN BLUE
Authors: Langley O. K.
Published: October 2006

—A study of the staining characteristics of Alcian blue in mammalian peripheral myelinated nerve in the presence of added electrolyte has enabled a comparison to be made of polyanions, formerly shown to be present at nodes of Ranvier, with other chemically defined macromolecules present in the same tissue. Two types of polyanion were shown to exist at nodes, one probably carboxylated and the other containing in addition sulphate ester groups. The possible physiological functions of such materials are discussed in relation to the role played by the nodes of Ranvier in conduction of the nerve impulse.
INCORPORATION IN VIVO OF RADIOACTIVE LEUCINE INTO NEURONAL AND GOAL NUCLEAR PROTEINS OF RAT BRAIN
Authors: Burdman J. A.
Published: October 2006

Purified neuronal and glial nuclei were separated from rat brain cells. The fraction rich in neuronal nuclei contained 68 ± 9 per cent neuronal nuclei and the fraction rich in glial nuclei contained 89 ± 6 per cent glial nuclei. The fraction rich in neuronal nuclei isolated from cells of adult rat brain incorporated l‐[4,5‐3H]leucine into TCA‐insoluble material at a rate comparable to those of the microsomal and the soluble fractions of the brain, and at a much higher rate than the fraction rich in glial nuclei. The proteins soluble in buffered‐saline, the acid‐soluble deoxyribonucleoproteins, and the residual proteins of the neuronal nuclei are apparently the proteins which account for the higher specific activity of neuronal proteins compared with glial nuclear proteins. In liver and kidney, the incorporation of [3H]leucine into nuclear proteins was lower than into other subcellular fractions from the same organs.
THE ACTIVATION OF THIAMINE DIPHOSPHATASE BY ATP IN RAT BRAIN
Authors: Inoue A. , Shim S. , Iwata H.
Published: October 2006

Abstract—

Thiamine diphosphatase (TDPase) of brain was activated by a low concentration of ATP.

In thiamine‐deficient rats TDPase activity in the brain increased significantly relative to that in pair‐fed animals, while in liver it decreased by the same amount as in the pair‐fed controls.

Liver TDPase was localized almost entirely in the soluble fraction, but in the brain it was bound to insoluble protein. On treatment with Triton X‐100 brain TDPase activity increased.

The ATP content of the brain of deficient rats, but not the ADP or AMP content, was significantly higher than in the control group. The level of inorganic phosphate in the brain and spinal cord of deficient animals was elevated markedly, while that of P‐creatine was unchanged.

The possible roles of brain TDPase in relation to nerve conduction and the blood‐brain barrier are discussed.
UPTAKE AND RELEASE OF 45Ca BY BRAIN MICROSOMES, SYNAPTOSOMES AND SYNAPTIC VESICLES1,2
Authors: Diamond I. , Goldberg A. L.
Published: October 2006

Abstract— Microsomes and synaptosomes from rat brain accumulated 4,5Ca against a concentration gradient by an ATP‐dependent process. Calcium accumulation occurred to the same extent in microsomes prepared from white matter and from grey matter, an observation suggesting that calcium uptake may be in part an activity of the axonal membrane. Microsomes and synaptosomes accumulated calcium to a similar extent but less actively than mitochondria. By contrast, synaptic vesicles showed relatively little calcium accumulation. Isotonic concentrations of sucrose, NaCl, KCl and choline chloride inhibited calcium accumulation, with NaCl and KCl the least effective of these inhibitory agents. No consistent effects on calcium uptake were obtained with adenosine 3′,5′‐monophosphate, dibutyryl cyclic AMP or the methyl xanthines.

Incubation of prelabelled microsomes resulted in a release of 45Ca, and ATP inhibited this release process. In the absence of added ATP, isotonic NaCl promoted calcium release to a significantly greater extent than KCl choline chloride or sucrose. In the presence of ATP, these agents all promoted a similar degree of release. Adenosine 3′,5′‐monophosphate or agents that affect its metabolism did not significantly affect calcium release. Magnesium ions reduced calcium release under all conditions tested.
THE EFFECTS OF ALTERED ENDOCRINE STATES AND OF ETHER ANAESTHESIA ON MOUSE BRAIN1
Authors: Passonneau Janet V. , Brunner E. A. , Molstad C. , Passonneau Rebecca
Published: October 2006

Abstract—

The effects of ether anaesthesia on metabolites of mouse brain in altered endocrine states has been examined. Alloxan diabetic mice, with elevated levels of blood and brain glucose, exhibited changes in brain metabolites after ether anaesthesia that were comparable to those seen in normal animals. Sympathectomized and/or adrenalectomized mice had decreased levels of brain glucose. The percentage elevation of glucose in the brains of these animals under ether anaesthesia approximated to normal values, although the absolute cerebral levels were lower. Increases in glycogen in the brains of these animals were somewhat diminished. In none of the altered endocrine states were the changes in brain metabolites following ether anaesthesia eliminated.

The activity of UDPglucose‐glycogen glucosyltransferase (UDPglucose: glycogen α‐4‐glucosyltransferasee, EC 2.4.1.11) in the mouse brain was measured in the absence and in the presence of glucose‐6‐P. Neither the total activity nor the percentage of the I form (measured in the absence of glucose‐6‐P) was altered by anaesthesia or by the endocrine state of the animal. The Michaelis constants with UDPglucose as substrate for the total and I forms were 0·36 mM and 1·0 mM, respectively. Considerable UDPglucose‐glycogen glucosyltransferase activity was observed in the absence of added glycogen primer. The observed increase in activity in the presence of added glucose‐6‐P was greater than would have been anticipated if the hexose phosphate were acting at only one site.