bluuebunny/crossref_metadata_2025 huggingface dataset:
Time‐dependent density functional theory studies of the electronic absorption spectra of metallophthalocyanines of group IVA
Authors: Zhang Yuexing , Cai Xue , Zhang Xianxi , Xu Hui , Liu Zhongqiang , Jiang Jianzhuang
Published: October 2006

Time‐dependent density functional theory (TD‐DFT) calculations were carried out in a comparative study of the electronic absorption spectra of lead(II) phthalocyaninate (PbPc), tin(II) phthalocyaninate (SnPc), tin(IV) dichlorophalocyaninate (PcSnCl2), germanium(II) phthalocyaninate (GePc), and germanium (IV) dichlorophalocyaninate (PcGeCl2) with the B3LYP method and LANL2DZ basis set. Our calculated bands correspond well with the experimental results. The electronic natures of all the bands in the absorption spectra are assigned and analyzed comparatively according to the calculated electronic transition contributions. With the increase of the dielectric constant from CHCl3 to DMSO, all the electronic absorption bands are somewhat red shift, consistent with the shift rules measured experimentally. The radius of the central metals has great influence to the absorption spectra, especially for the B bands. The influence of the radius of the central metals to the absorption spectra of PcSnCl2 and PcGeCl2 is smaller than to the spectra of the nonplanar MPcs (M = Pb, Sn, and Ge). Axial ligands also greatly changed the electronic absorption spectra due to the change of the orbital energy level and the molecular symmetry. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Solving constrained mechanical systems by the family of Newmark and α‐methods
Authors: Lunk Ch. , Simeon B.
Published: October 2006

The family of Newmark and generalized α‐methods is extended to constrained mechanical systems by using simultaneous position and velocity stabilization as key ideas. In this way, the acceleration constraints need not be evaluated, and the overall algorithm is about as expensive as the application of a BDF method to the GGL‐stabilized equations of motion. Moreover, the RATTLE method of molecular dynamics is included as special case. A convergence analysis of the presented α‐RATTLE algorithm shows global second order in both position and velocity variables while the Lagrange multipliers are computed to first order accuracy. Additonally, the property of adjustable numerical dissipation carries over from the unconstrained case.
Differential expression of phospholipases D1 and D2 in mouse tissues
Authors: Kim Heechul , Lee Jeeyoung , Kim Seungjoon , Shin Min Kyoung , Min Do Sik , Shin Taekyun
Published: October 2006

The differential expression of phospholipase D (PLD) isozymes, which include PLD1 and PLD2, was examined in various murine tissues, including the cerebrum, cerebellum, heart, lung, liver, spleen, stomach, pancreas, ileum, colon, adrenal gland, kidneys, testes, ovaries, and uterus.

In Western blot analysis, only PLD1 was detected in the heart and ovary, while only PLD2 was detected in the pancreas and ileum. Both PLD1 and PLD2 were strongly expressed in the cerebrum, cerebellum, and lung, and both were also expressed in the liver, spleen, stomach, colon, kidney, testes, and uterus.

Immunohistochemistry showed intense PLD immunostaining in the cerebrum, cerebellum, lungs, intestines, and testis, and weak PLD immunostaining in the liver, kidneys, spleen, and heart.

These findings suggest that PLD1 and PLD2 are differentially expressed in the various organs of mice, and that each PLD isozyme plays a distinct role in each organ.
Ejecta deposit thickness, heat flow, and a critical ambiguity on the Moon
Authors: Hagermann A. , Tanaka S.
Published: October 2006

The Apollo lunar heat flow measurements gave values of 21 and 16 mW m−2 which, after extrapolation based on thorium abundances, yields a global estimate of 18 mW m−2. A refinement of the assumptions of the subsurface structure and the resulting focusing of heat flux later led to a revision of the global value to 12 mW m−2. We think that to date none of the models linking the Apollo heat flow measurements has sufficiently highlighted a critical source of ambiguity. Little attention has been paid to the full magnitude of the uncertainty in these measurements caused by near–surface Thorium abundances and the local thickness of the ejecta blanket generated by the Imbrium impact. In a simple study we show that lunar heat flow is contingent upon the thickness of the ejecta blanket of the hypothetical impact. A model with an exponential decrease of Th concentration with depth can explain the difference in surface heat flow between the Apollo 15 and the Apollo 17 measurements. A constant Thorium concentration within the ejecta layer amplifies this effect. The variation in local surface Th abundance, if taken as representative of the subsurface Th distribution within the ejecta blanket, amplifies the uncertainty. We conclude that further measurements are essential for making well‐founded statements about the subsurface abundance of radioactive elements, mantle heat flux and the thermal state of the Moon.
Reaction dynamics of OH+(Σ−3)+C2H2 studied with crossed beams and density functional theory calculations
Authors: Liu Li , Martin Courtney , Farrar James M.
Published: October 2006

The reactions between OH+(Σ−3) and C2H2 have been studied using crossed ion and molecular beams and density functional theory calculations. Both charge transfer and proton transfer channels are observed. Products formed by carbon-carbon bond cleavage analogous to those formed in the isoelectronic O(P3)+C2H2 reaction, e.g., C3H2+HCO+, are not observed. The center of mass flux distributions of both product ions at three different energies are highly asymmetric, with maxima close to the velocity and direction of the precursor acetylene beam, characteristic of direct reactions. The internal energy distributions of the charge transfer products are independent of collision energy and are peaked at the reaction exothermicity, inconsistent with either the existence of favorable Franck-Condon factors or energy resonance. In proton transfer, almost the entire reaction exothermicity is transformed into product internal excitation, consistent with mixed energy release in which the proton is transferred with both the breaking and forming bonds extended. Most of the incremental translational energy in the two higher-energy experiments appears in product translational energy, providing an example of induced repulsive energy release.
Multichord optical interferometry of FRX-L’s field reversed configuration
Authors: Ruden E. L. , Zhang Shouyin , Wurden G. A. , Intrator T. P. , Renneke R. , Waganaar W. J. , Analla F. T. , Grabowski T. C.
Published: October 2006

A 0.633μm laser interferometer provides detailed time resolved information about the spatial distribution of the plasma density of field reversed configurations (FRC’s) produced by the FRX-L experiment at Los Alamos National Laboratory. This experiment is an effort to produce a magnetized plasma with closed field lines suitable for compression by a solid metal liner imploded by the Shiva Star capacitor bank at the Air Force Research Laboratory. The interferometer probes a fanned array of eight chords through the FRC midplane, measuring the line integrated free electron density via its effect on optical phase shift relative to eight reference beams as a function of time. The reference beams are given nominally identical optical paths, except that they are folded for compactness and given an 80MHz higher optical frequency by use of a Bragg cell beam splitter. After the beams are recombined, interference results in 80MHz electromagnetic beat waves with dynamic phase shifts equal to those of the corresponding optical probes. Quadrature mixing of the electronically monitored light is then performed with rf components. Noteworthy features of the interferometer’s design are the unique compact folding scheme of the reference paths, inclusion of a fused quartz tube in the reference path similar to that of the FRC’s vacuum vessel to compensate for cylindrical lensing, and transmission of the interfering light via optical fibers to a rf shielded room for processing. Extraneous contributions to the phase shift due to vibration resulting from the system’s pulsed magnetic field, and dynamic refractive changes in or near the fused quartz tube wall (possibly due to radiation heating) are corrected for.
Electrostatically actuated resonance of amorphous silicon microresonators in water
Authors: Adrega T. , Chu V. , Conde J. P.
Published: October 2006

The resonance of electrostatically actuated amorphous silicon microbridges immersed in de-ionized water is characterized. It is shown that under correct actuation conditions resonance can be measured in water without electrolysis or electrode screening. The resonance frequency of these nonpassivated structures is also studied in air and under vacuum for microbridges with different lengths. When the operating medium is changed from vacuum to air, the resonance frequency decreases by 5% and the quality factor decreases from approximately 1000 to 100. Operation in de-ionized water produces a 60% shift in resonance frequency to lower values and the quality factor decreases to 10.
Thermal noise driven computing
Authors: Kish Laszlo B.
Published: October 2006

A new type of computing, where thermal noise is the information carrier and the clock in a computer, is proposed. The energy requirement/dissipation is studied in a simple digital system with zero threshold voltage when the thermal noise is equal to or greater than the digital signal. In a simple realization of a thermal noise driven gate, the lower limit of energy needed to generate the digital signal is ≈1.1kT∕bit. The arrangement has potentially improved energy efficiency and it is free of leakage current, cross-talk, and ground plane electromagnetic interference problems. Disadvantage is the larger number of required elements.
Theoretical hardness of PtN2 with pyrite structure
Authors: Gou Huiyang , Hou Li , Zhang Jingwu , Sun Guifang , Gao Lihua , Gao Faming
Published: October 2006

Using first-principles technique, the authors have investigated the structural, mechanical, and electronic properties of the PtN2 with cubic pyrite and orthorhombic FeS2 structure. The calculated results of the pyrite-type PtN2 are in agreement with the available theoretical and experimental values. The pyrite-type PtN2 is more energetically stable under the ambient condition. Results indicate that the two PtN2 phases are semiconducting materials. Based on Mulliken overlap population analysis in first-principles technique, the hardness of both the cubic and orthorhombic PtN2 is predicted. Results show that the PtN2 with pyrite structure possesses excellent mechanical properties.
Staphylococcus aureusFibronectin Binding Protein-A Induces Motile Attachment Sites and Complex Actin Remodeling in Living Endothelial Cells
Authors: Schröder Andreas , Schröder Barbara , Roppenser Bernhard , Linder Stefan , Sinha Bhanu , Fässler Reinhard , Aepfelbacher Martin
Published: October 2006

Staphylococcus aureus fibronectin binding protein-A (FnBPA) stimulates α5β1-integrin signaling and actin rearrangements in host cells. This eventually leads to invasion of the staphylococci and their targeting to lysosomes. Using live cell imaging, we found that FnBPA-expressing staphylococci induce formation of fibrillar adhesion-like attachment sites and translocate together with them on the surface of human endothelial cells (velocity ∼50 μm/h). The translocating bacteria recruited cellular actin and Rab5 in a cyclic and alternating manner, suggesting unsuccessful attempts of phagocytosis by the endothelial cells. Translocation, actin recruitment, and eventual invasion of the staphylococci was regulated by the fibrillar adhesion protein tensin. The staphylococci also regularly produced Neural Wiskott-Aldrich syndrome protein-controlled actin comet tails that further propelled them on the cell surface (velocity up to 1000 μm/h). Thus, S. aureus FnBPA produces attachment sites that promote bacterial movements but subvert actin- and Rab5 reorganization during invasion. This may constitute a novel strategy of S. aureus to postpone invasion until its toxins become effective.
INCORPORATION OF [14C]AMINO ACIDS INTO THE PROTEOLIPID OF SUBCELLULAR PREPARATIONS OF RAT BRAIN IN VITRO*
Authors: MOKRASCH L. C.
Published: October 2006

IN a previous report (MOKRASCH and MANNER, 1963) some of the characteristics of the incorporation of p4C]amino acids and pT]palmitate into the proteolipid from rat brain slices were detailed. This report deals with a further resolution of the incorporating system in centrifugal subfractions of rat brain homogenate. Some similarities in the reaction condition requirements are seen when the incorporations for slices are compared with those for particle preparations. Differences between the incorporation of p4C]amino acids into ptoteolipid by the system used here and incorporation by microsomal systems ate several.

A report with preliminary information on the particulate system has appeared (MOKRASCH, 1963).
STRUCTURAL STUDIES ON SULPHATIDES IN METACHROMATIC LEUCODYSTROPHY
Authors: Malone Michael J. , Stoffyn Pierre , Moser Hugo
Published: October 2006

Sulphatides have been isolated by a newly developed method from the brain white matter of normal human adult and child, and of two patients with metachromatic leucodystrophy.

Only galactose was found in chromatographic analysis of the carbohydrate component. Following permethylation of the sulphatides, the methylated hexose, in all cases, was 2,4,6‐trimethylgalactose.

The sulphate group is located solely at the C‐3 position of the galactopyranose moiety, and in metachromatic leucodystrophy, although there is an accumulation of sulphatides, their composition and structure remain normal.
FLUID COMPARTMENTATION AND ELECTROLYTES OF CAT CEREBRAL CORTEX IN VITRO–III ONTOGENETIC AND COMPARATIVE ASPECTS*
Authors: Tower Donald B. , Bourke Robert S.
Published: October 2006

Studies on swelling and fluid compartmentation have been carried out in vitro on incubated slices of cerebral cortex from kittens 1.5‐120 days post‐natal age and on incubated sections of corpus callosum and slices of liver and kidney cortex from adult cats. The findings have been compared with analogous data for incubated slices of adult cat cerebral cortex, studied under identical conditions (Bourke and Tower, 1966a, b), in order to identify the probable morphological correlates of fluid and electrolyte distribution.

Incubated cortical slices from neonatal (1.5‐4‐day‐old) kittens exhibit none of the relevant characteristics of slices from adult cerebral cortex. By 1 month post‐natal age, K+‐dependent swelling of slices becomes demonstrable, and the K+ and Na+ contents of slices approximate adult levels. Both these developments coincide with the morphological and physiological maturation of cortical neurons. At 3 months post‐natal age, slice swelling accessible to C1− but not to sucrose becomes observable and the dependence of sucrose space size on time, during incubation, of solute addition becomes demonstrable. Both these developments follow completion of axonal myelination in the cortex but coincide with the period of cortical glial cell proliferation.

Incubated sections of corpus callosum from adult cats exhibit none of the relevant characteristics observed for cortical slices under identical conditions. Tissue swelling is minimal and uninfluenced by K+ concentrations of incubation media. Tissue fluid spaces accessible to sucrose are approximately twice the size of spaces accessible to inulin. In general, qualitatively similar results have been obtained for incubated slices of cat liver or kidney cortex or for incubated sections of rat diaphragm under the same conditions. A behaviour for glial cells (? astrocytes) in cerebral cortex under such in vitro conditions distinctly different from behaviour of subcortical glial cells is suggested.
THE QUANTITATIVE HISTOCHEMISTRY OF A CHEMICALLY INDUCED EPENDYMOBLASTOMA–II THE EFFECT OF ISCHAEMIA ON SUBSTRATES OF CARBOHYDRATE METABOLISM*
Authors: Maker Howard S. , Lehrer Gerard M. , Weiss Cipora , Silides Demetra J. , Scheinberg Labe C.
Published: October 2006

Several metabolic intermediates of glycolysis have been assayed by sensitive, quantitative microtechniques in an experimental mouse ependymoblastoma growing in brain and in cerebral hemispheres of the tumour‐bearing animals after exposure to varying periods of ischaemia prior to freezing. Initial levels of glucose and lactate were higher, and ATP and glucose‐6‐phosphate lower, in the ependymoblastoma than in brain. During ischaemia glucose fell and lactate increased less rapidly in the tumour than in brain. The overall patterns of change in glucose‐6‐phosphate were similar in tumour and brain although the level of glucose‐6‐phosphate was consistently lower in the ependymoblastoma. ATP was very low in the tumour at the time of decapitation and it declined less precipitously than in brain, so that after 2 min of ischaemia levels were similar in the two tissues.
COMPARATIVE STUDIES ON THE OXIDATION OF 5‐HYDROXYTRYPTAMINE AND 3,4‐DIMETHOXY‐ PHENYLETHYLAMINE IN RAT, DOG AND HUMAN BRAIN
Authors: Huszti Z. , Borsy J.
Published: October 2006

Abstract— Comparative studies were carried out on 5‐hydroxytryptamine (5‐HT) and 3,4‐dimethoxyphenylethylamine (DMPEA) oxidation using brain homogenates from different animals as the source of enzyme. Differences in the enzyme saturation curves, in the inhibitor spectra and variations of enzyme activity depending on the substrate used, suggested that the enzymes taking part in the oxidation of 5‐HT and of DMPEA slightly differ from each other. Differences were interpreted on the basis of the heterogeneity of monoamine oxidase (MAO), suggested by earlier investigations. Thus the possibility of an individual inhibition of the degradation of certain amines has to be considered.
PYRIMIDINE SYNTHESIS IN TISSUE CULTURE1
Authors: Appel S. H. , Silberberg D. H.
Published: October 2006

Abstract— Myelinated cerebellar tissue culture (organ culture) was used to assess the salvage and de novo pathways of pyrimidine synthesis in mammalian brain. Radioactive orotic acid and carbamyl aspartic acid were readily incorporated into UMP and into perchloric acid‐insoluble RNA. The incorporation was effectively blocked by azauridine. Neither radioactive sodium bicarbonate or citrulline was incorporated into UMP or blocked by azauridine. [3H]Uridine, on the other hand, rapidly entered the cultures, was incorporated into UMP and perchloric acid‐insoluble material, and was partially inhibited by azauridine. The failure to demonstrate activity of carbamyl phosphate synthetase suggests the potential importance of the salvage pathway and the likely dependence of the brain upon exogenous and endogenous pyrimidine precursors.
DECOMPOSITION OF PHOSPHOLIPIDS DURING WALLERIAN DEGENERATION J. DOMONKOS
Authors: Domonkos J. , Heiner L.
Published: October 2006

—Of the lipid metabolic changes in Wallerian degeneration, the decomposition of phosphatides was studied in the early stages, 2–14 days after the nerve had been cut. It was found that the decomposition of phosphatides begins only 6 days after section. The amounts of lipid‐P and fatty acid ester decrease in parallel. However, a greatcr decrease in the amount of fatty aldehyde was observed than of the lipid‐P and fatty acid ester; this indicates that the vinyl ether bonds of glycerophosphatides are more sensitive to the degenerative process than the fatty acid ester or phosphorus.

The fatty acid ester: lipid‐P ratio, calculated from the results, does not change; however, the fatty aldehyde: lipid‐P ratio shows a marked decrease during this same period. The values of the ratios indicate that in the 2nd week following nerve section, decomposition of glycerophosphatides containing fatty aldehyde (i.e. plasmalogens), in contrast to glycerophosphatides of diacyl form, may be only partial. Thus, in the 2nd week of Wallerian degeneration the formation of lysophosphatides may be presumed to come from the plasmalogens.
EFFECT OF PYRIDOXINE DEFICIENCY ON AROMATIC l‐AMINO ACID DECARBOXYLASE IN THE DEVELOPING RAT LIVER AND BRAIN
Authors: Eberle Elizabeth D. , Eiduson S.
Published: October 2006

—Maternal pyridoxine deficiency begun 2 weeks before mating and continued throughout pregnancy and the nursing period resulted in diminished wt. gains in the brain, the liver and the body in the first 16 days of life, as well as lowered levels of the aromatic l‐amino acid decarboxylase in both brain and liver tissue. The fetus was protected from the effect of vitamin B6 deficiency during pregnancy, since at birth the body wt., organ weights, and decarboxylase levels in these tissues were comparable to those of control litters. The brain was affected less than the liver, both in rate of wt. increase and decarboxylase activity.

The cerebellum normally developed measurable decarboxylase activity only during the second week of life. The cortex normally slowly increased its low decarboxylase activity during the first week postnatally, with a more rapid increase during the second week. This rapid increase was primarily in the holoenzyme moiety. The rest of the brain, which had well developed levels of decarboxylase activity at birth, normally showed a sharp increase during the second week of life which was also largely in the holoenzyme portion. When the increasing weights of these tissues were considered, it became obvious that the total amount of apoenzyme as well as the amount of holoenzyme were increasing in the normally developing rat, although the greatest amount of the change was in the holoenzyme form.

The liver normally showed a much more rapid increase in decarboxylase activity than did the brain, and showed the increase much earlier. The holoenzyme normally increased rapidly after the first 4 days, whereas the apoenzyme concentration levelled off at this time.

The effect of the pyridoxine deficiency on decarboxylase activity was almost entirely on the holoenzyme form of the decarboxylase, since the apoenzyme form generally remained the same in the control and the deficient pups during development.

There appeared to be no decarboxylase inhibitor present in pyridoxine deficient tissues, nor any evidence in control tissues for an enzyme required for the activation of the decarboxylase by cofactor.
IN VITRO RNA SYNTHESES BY INTACT RAT BRAIN NUCLEI1
Authors: Dutton G. R. , Mahler H. R.
Published: October 2006

Abstract— The characteristics of DNA‐dependent RNA polymerase activity in intact rat cerebral cortex nuclei tested at low ionic strength are presented. The system was most dependent on the presence of spermidine and an ATP‐generating system and to a lesser extent on Mg2+ and K+ for maximal incorporation. Substitution of Mg2+ by Mn2+ or of K+ by Na+ resulted in substantially less activity than under the optimum conditions described. Maximal incorporation was about 10 per cent that of brain nuclear systems of high ionic strength.

In addition, the labelling patterns of the in vitro RNA products were shown to be very similar to those found in vivo. The stability of isolated nuclei toward degradation of RNA synthetic capacity and products formed was much greater than that of a similar liver system.
CHOLINE ACETYLTRANSFERASE ACTIVITY AND TOTAL PROTEIN CONTENT IN SELECTED OPTIC AREAS OF THE RAT AFTER COMPLETE LIGHT‐DEPRIVATION DURING CNS DEVELOPMENT1
Authors: Maletta G. J. , Timiras P. S.
Published: October 2006

Abstract— Choline acetyltransferase (acetyl‐CoA: choline 0‐acetyltransferase, I.U.B. 2.3.1.6) activity and total protein content in visual and extra‐visual areas were compared in normal Long‐Evans rats and in rats subjected to complete light‐deprivation for 21 days from birth. The enzyme activity and the protein content in the superior colliculi, lateral geniculate bodies and visual cortex, as well as in the sensory‐motor cortex, hypothalamus, brain stem and cerebellum, were measured in both mothers and progeny. By means of a radiochemical technique modified in this laboratory, a significant decline of ChAc activity was observed in the lateral geniculate bodies and superior colliculi, with no significant decline in the visual cortex of the experimental progeny. Total protein content, measured colorimetrically, was significantly decreased in the superior colliculi of the progeny. The biochemical data obtained from all other brain areas in the experimental animals (progeny and mothers) and controls demonstrated no marked differences. The enzymic alterations observed in the cholinergic system of progeny after complete light‐deprivation during this critical period of CNS development can be specifically correlated with decreased functional maturation of the visual system. If it is accepted that ACh is a neuro‐transmitter in some parts of the visual pathway, the data presented here suggest that complete light‐deprivation from birth to 21 days of age in the rat has an effect on a biochemical system involved in synaptic transmission.
ON THE SITE OF ACTION OF PHOSPHATIDE ACYL‐HYDROLASE ACTIVITY OF RAT BRAIN HOMOGENATES ON LECITHIN
Authors: WEBSTER G. R. , COOPER MARY
Published: October 2006

Abstract— ‐The hydrolysis of 2‐ [14C]acyl‐labelled and [Me‐3H]choline‐labelled lecithins by rat brain homogenates has been studied. The acyl‐labelled substrate was hydrolysed with the production of both radioactive lysolecithin and radioactive free fatty acid in the proportions of 60 per cent and 40 per cent; traces of labelled mono‐ and diglyceride were also formed.

In addition to radioactive lysolecithin the [3H]choline‐labelled lecithin also gave rise to much smaller amounts of radioactive water soluble derivatives, consisting almost entirely of free choline and phosphorylcholine with only traces of glycerylphosphorylcholine.

The results provide evidence for the production of a mixture of 1‐ and 2‐acyl isomers of lysolecithin by phospholipase action in brain homogenates at pH 7·4, the latter predominating slightly.
CAT BRAIN MUCOPOLYSACCHARIDES AND THEIR IN VIVO HYALURONIDASE DIGESTION
Authors: Custod J. T. , Young I. James
Published: October 2006

Abstract— ‐The average yield of mucopolysaccharides isolated from adult cat brain was 3·29 mg, representing 0·02 per cent of the wet wt. of brain tissue. The lipid‐free dried brain was approximately 10 per cent of the wet brain tissue weight. Mucopolysaccharide fraction distributions and concentration ratios are presented.
THE EFFECT OF HYPERCAPNIA IN VIVO ON RAT BRAIN GANGLIOSIDES
Authors: Holm M. R.
Published: October 2006

Abstract— ‐An investigation on the effect of hypercapnia in vivo on the rat brain gangliosides is reported. In contradiction to the results reported by Lowden and Wolfe (1964) for the cat, no diminution in total brain ganglioside concentration could be demonstrated. The ganglioside pattern in test and control animals was the same.
THE EFFECT OF AMINO‐OXYACETIC ACID ON BRAIN CATECHOLAMINES
Authors: Buniatian H. Ch. , Yessaian N. H.
Published: October 2006

Abstract— —Administration of amino‐oxyacetic acid (AOAA) to rats induced a pronounced decrease of midbrain norepinephrine (NE) and adrenal epinephrine (E) after 30 min, at which time the GABA level of midbrain had increased to 117 per cent of the initial value. The concentrations of NE in the pons‐medulla and of dopamine (DA) in the cerebral hemispheres were not changed.

Further increases in brain GABA were accompanied by a rise of NE in midbrain and pons‐medulla beginning 1 hr after AOAA administration. A rise of cerebral DA level was observed only after 4 hr. Six hours after AOAA administration the levels of both NE and DA in brain were reduced.

From the results of these and other studies, where administration of small amounts of GABA were shown to affect brain NE and serotonin levels, it is suggested that monoamines may be involved in the physiological action of GABA in the brain.
AMINOACYL‐RNA SYNTHETASE AND TRANSFER RNA BINDING ACTIVITY DURING EARLY MAMMALIAN BRAIN DEVELOPMENT1
Authors: Johnson T. C.
Published: October 2006

Abstract— Aminoacyl‐RNA synthetase activity in mouse brain tissue was measured during the first few days after birth. Although the rate of protein synthesis rapidly diminished during this period, the activity of these specific enzymes was not reduced. In contrast, the binding of tyrosine and arginine was actually greater when the older enzyme preparations were employed. The ability of tRNA to bind amino acids during this critical stage of development was tested. Preparations of tRNA, isolated from 2‐, 7‐, 11‐ and 13‐day‐old, and adult brain tissue were employed with both young and old enzymes. No significant loss in binding activity was measured with these tRNA preparations.
THE EFFECT OF ANTIOXIDANT‐DEFICIENCY ON PHOSPHOLIPID COMPOSITION IN THE CHICK BRAIN1
Authors: Witting L. A.
Published: October 2006

Abstract— A significant increase in arachidonate was noted in the total phospholipids of brain of chicks with nutritional antioxidant‐deficiency and encephalomalacia. After thin‐layer chromatography of the brain lipids, this increase in arachidonate was found to be restricted to the phosphatidyl serine fraction. Significant decreases in docosahexaenoate and docosapentaenoate were noted in the phosphatidyl ethanolamine fraction. The changes in fatty acid composition of phospholipids in chick brain are comparable to those previously observed in phospholipids of skeletal muscle, liver and testes of the rat.
THE EFFECT OF HYPOCHOLESTEREMIC AGENTS ON MYELINOGENESIS
Authors: Fumagalli R. , Smith Marion E. , Urna G. , Paoletti R.
Published: October 2006

Abstract— Three drugs known to inhibit biosynthesis of cholesterol, Clofibrate, 20, 25‐diazacholesterol and AY‐9944 were administered by stomach intubation to suckling rats. At weaning the rats were killed and subcellular fractions, including myelin, were prepared from the brains and spinal cords and analysed for sterol content. Central nervous tissue fractions from Clofibrate‐treated rats showed some decrease in total sterols, but the sterol species were qualitatively normal. AY‐9944 given to rats caused high amounts of 7‐dehydro‐cholesterol to accumulate in all brain and spinal cord fractions with the highest amounts (32–38 percent of total sterols) in myelin. In diazasterol‐treated rats desmosterol reached 48 per cent of the sterols of myelin. A group of rats was allowed to survive after the final drug intake (21 days) and their brain and spinal cord sterol content followed up to 60 days. At 30 days the proportion of dehydrocholesterol or desmosterol comprised over half the total myelin sterol. By 60 days of age the 7‐dehydrocholesterol had almost completely disappeared from all fractions while substantial amounts of desmosterol were retained in myelin. Myelination was retarded by treatment with AY‐9944 and 20, 25‐diazasterol, possibly by the limited amount of sterols available. The metabolism of the abnormal myelin constituents in drug‐treated animals is discussed in relation to the molecular structure of the myelin membrane.
HOMOVANILLIC ACID AND 5‐HYDROXYINDOLEACETIC ACID IN THE CEREBROSPINAL FLUID OF PATIENTS WITH SENILE DEMENTIA, PRESENILE DEMENTIA AND PARKINSONISM
Authors: Gottfries C. G. , Gottfries I. , Roos B. E.
Published: October 2006

Abstract— Four groups, one of healthy volunteers, one of senile dementia, one of presenile dementia, and one of patients with parkinsonism were compared according to the values of HVA and 5‐HIAA in CSF. The levels of HVA and 5‐HIAA were highest in the group of healthy volunteers and decreased in the following order: senile dementia, presenile dementia, and parkinsonism. In the groups the two metabolites were positively correlated. These results are in agreement with earlier investigations showing disturbances of monoamine metabolism in the brain of patients suffering from these syndromes.
CONCENTRATION AND FATTY ACID COMPOSITION OF CHOLESTERYL ESTERS OF NORMAL HUMAN BRAIN1
Authors: Alling C. , Svennerholm L.
Published: October 2006

Abstract— —Cholesteryl esters were isolated from the cerebral cortex and white matter of human brains at different ages, and their concentration and composition determined.

The esters were separated from other lipids by chromatography on silicic acid and finally purified by TLC. The fatty acids were converted to the methyl esters by alkaline trans‐methylation and analysed by GLC. A TLC method was elaborated for quantitative determination of small amounts of cholesteryl esters in the presence of free cholesterol.

The concentration of cholesteryl esters was only 0·1–0·2 per cent of the total cholesterol content of cerebral tissue in older children and adults. During early myelination the concentration was many times greater, especially in the white matter but it never exceeded 2 per cent of the total cholesterol in any subject.

The major fatty acids of human brain cholesteryl esters were oleic, palmitic, palmitoleic and arachidonic acid. After completion of myelination, arachidonic acid constituted the major fatty acid. There were fairly small differences in the fatty acid pattern of the cholesteryl esters between grey and white matter, but the concentration of polyunsaturated fatty acids was larger in the grey matter.

Cholesteryl esters appear to play an important role in the metabolism of the phosphoglyceride fatty acids in cerebral tissue.
ACETYLCHOLINE ESTERASE ACTIVITY OF SYNAPTIC VESICLE FRACTIONS AND MEMBRANE FRACTIONS PREPARED FROM RAT BRAIN TISSUE1
Authors: Trotter J. L. , Burton R. M.
Published: October 2006

Abstract— —The synaptic vesicle fraction, M2, isolated from rat brain tissue contained acetylcholine, acetylcholine esterase activity, and gangliosides. The separation of M2 into several subfractions showed that the enriched synaptic vesicle subfraction, M2A, contained acetylcholine, but little acetylcholine esterase and ganglioside. The membrane subfraction, M2B, was enriched in the enzyme and ganglioside. Calcium ions facilitated the removal of membrane material from the synaptic vesicle fraction. In addition, the acetylcholine esterase of the synaptic vesicle fractions, M2 and M2A, frequently were activated by calcium ions as well as other cations.
RNA BASE RATIO CHANGES IN PLANARIA DURING CONDITIONING
Authors: Hydén H. , Egyházi E. , John E. R. , Bartlett F.
Published: October 2006

Abstract— —Four groups of planaria were stimulated with light and shock: Group LAC received light systematically paired with shock delivered while the animal's head was oriented toward the cathode. Group LAA received light systematically paired with shock delivered while the animal's head was oriented toward the anode. Group L=C received light in random temporal relationship to cathodal head shock. Group L=C=A received light in random temporal relationship to randomized cathodal or anodal shock.

Groups LAC animals acquired a conditioned flexion reflex in contrast to the other three groups. As each animal in Group LAC reached criterion, one animal which had received an equated amount of light and shock stimulation was selected from each of the other three groups. Each such set of four animals was fixed in Carnoy's solution and imbedded in paraffin. All subsequent analyses were run‘blind’in a different laboratory. Nerve cells from the head ganglion and from the tail were isolated with a micromanipulator after sectioning and pre‐treatment. RNA was extracted and base ratios determined by micro‐electrophoresis.

The relationship of base ratio differences between groups to conditioning and stimulation is discussed.
THE EFFECT OF ELECTRICAL STIMULATION UPON THE ACCUMULATION OF ADENOSINE 3′,5′‐PHOSPHATE IN ISOLATED CEREBRAL TISSUE
Authors: Kakiuchi S. , Rall T. W. , McIlwain H.
Published: October 2006

Abstract—

The application of electrical pulses to slices of guinea pig cerebral cortex led to an increase in the levels of adenosine 3′,5′‐phosphate (cyclic 3′,5′‐AMP) of more than 11‐fold within 10 min. This effect of electrical pulses was severely reduced in the presence of theophylline. Cyclic 3′,5′‐AMP accumulation in slices was increased in the presence of norepinephrine and histamine about 1·5‐fold and six‐fold, respectively; the effect of electrical pulses was augmented in the presence of maximal amounts of either amine. For these and other reasons, the accumulation of cyclic 3′,5′‐AMP induced by electrical stimulation cannot be ascribed to the release and action of either histamine or norepinephrine.
METABOLIC EFFECTS OF AZASERINE IN RAT BRAIN
Authors: Held Irene , Wells W. , Koenig H.
Published: October 2006

Abstract—

The de novo biosynthesis of purine nucleotides in rat brain was markedly and rapidly inhibited by intracerebral injections of azaserine. After 48 hr the animals became paraplegic. The biosynthesis of purine and pyrimidine nucleotides, RNA and protein was investigated by radioactive tracer studies over a 4‐day period in an attempt to correlate the azaserine‐induced, metabolic lesions found in rat brain and the manifested, peripheral, neurological disturbance.
BIOCHEMICAL CHANGES IN β,β′‐IMINODIPROPIONITRILE‐TREATED RAT BRAIN AND PREVENTION OF TOXICITY BY ETHIONINE
Authors: Brownlow E. K. , Heath H.
Published: October 2006

Abstract—

The administration of β,β′‐iminodipropionitrile (IDPN) to rats, either in five daily injections of 30 mg, or in a single injection of 100 mg/100 g body wt., resulted in the development of severe damage to the central nervous system and retinal vasculature. These changes were prevented by the daily intraperitoneal injection of 24 mg dl‐ethionine/100 g body wt.

Significant increases in the oxygen uptake of IDPN‐treated rat brain were found when measured in the presence of succinate or glutamate as substrates. IDPN (5 mm) did not affect the oxygen uptake of brain homogenates in vitro when measured in the presence of the same substrates.

The cytochrome oxidase activity of rat brain was not significantly changed by in vivo administration of IDPN, nor by the presence of 5 mm‐IDPN in vitro.

The lactate content of the IDPN‐treated rat brain was significantly increased by the eighth day.

There were no changes in the dry wt., total protein, lipid or phospholipid content of the IDPN‐treated rat brain, even after 4 weeks.

These findings are discussed with reference to previous experiments on the toxic action of IDPN on the central nervous system and retinal vasculature.
COMPARATIVE STUDIES OF HIGHLY BASIC PROTEINS OF OX BRAIN AND RAT BRAIN. MICROHETEROGENEITY OF BASIC ENCEPHALITOGENIC (MYELIN) PROTEIN
Authors: Martenson R. E. , Gaitonde M. K.
Published: October 2006

Abstract—

(1) The total amount of highly basic proteins in acid extracts of whole ox brain, ox white matter and ox grey matter was determined quantitatively after electrophoresis on 5% polyacrylamide gels at pH 10‐6 in the presence of 8 M‐urea.

(2) Ox white matter gave 13 mg and ox grey matter 2 mg of highly basic proteins per g fresh tissue on treatment with 0‐03 n‐HCl. The yield of total basic proteins of ox white matter increased to 17‐6 mg/g fresh brain on stepwise extraction at pH 3‐0, 2‐0 and 1‐0; the extract at pH 3.0 accounted for 90 per cent of the total basic proteins.

(3) The high encephalitogenic activity of the fraction of highly basic proteins extracted at pH 3.0 from ox white matter indicated that these basic proteins were derived from myelin. It is suggested that the amount of basic proteins in a sample of brain extracted under these conditions is proportional to the amount of white matter in the sample.

(4) The encephalitogenic (myelin) basic protein fraction was homogeneous with respect to molecular size but could be resolved into at least six components by electrophoresis at high pH.

(5) The myelin basic proteins extracted from ox white matter had lower electrophoretic mobilities at high pH than did those of two basic proteins of rat brain apparently derived from myelin.
GLUCOSE AND AMINO ACID METABOLISM IN SOME INVERTEBRATE NERVOUS SYSTEMS
Authors: Bradford H. F. , Chain E. B. , Cory Helene T. , Rose S. P. R.
Published: October 2006

Abstract—

(1) The in vitro metabolism of [U‐14C]glucose and [U‐14C]glutamate was compared in snail, octopus and locust ganglia, and in rat cerebral cortex.

(2) The metabolic patterns are quantitatively similar. The major labelled metabolites formed from glucose or glutamate by rat cortex and the invertebrate systems were CO2, aspartate, glutamate, glutamine and alanine. γ‐Aminobutyric acid (GABA) was formed in substantial amounts only by locust and rat.

(3) A much larger proportion of labelled glucose and glutamate was converted to alanine by the invertebrates compared with rat cortex, although 14CO2 production was lower.

(4) The effect of glucose in reducing aspartate formation and stimulating glutamine formation from [U‐14C]glutamate in mammalian cortex was observed in the locust but not in the molluscs.

(5) Labelled citric acid cycle intermediates were formed in substantial quantities from glucose and glutamate only by snail and locust.
GLUCOSE AND AMINO ACID METABOLISM IN OCTOPUS OPTIC AND VERTICAL LOBES IN VITRO
Authors: Cory Helene T , Rose S. P. R.
Published: October 2006

Abstract—

(1) The metabolism of glucose and amino acids in vitro was compared in the rat cerebral cortex and the optic and vertical lobes of the octopus brain.

(2) Specific activities and pool sizes of the five amino acids, glutamate, aspartate, glutamine, alanine and γ‐aminobutyric acid (GABA), were determined in octopus and rat brain slices after 2 hr incubation with 10 mm‐[U‐14C]glucose, 10 mm‐L‐[U‐14C]glutamate, and 10mm‐L‐[U‐14C]glutamate with added 10 mM‐glucose. Amino acid pool sizes were similar in rat and octopus brain, with the exception of alanine, which was higher in the octopus. Generally specific activities were from four‐ to 20‐fold higher in rat brain. With [U‐14C]glucose as substrate, specific activities of GABA and glutamate were highest in rat; those of alanine and glutamine highest in octopus brain. With L‐[U‐14C]glutamate the specific activities of GABA and aspartate were highest in rat, that of aspartate highest and GABA lowest in octopus. The addition of glucose to L‐[U‐14C]glutamate as substrate had little effect on the specific activities of any of the amino acids.

(3) The uptake of some amino acids was determined by incubation with [U‐14C]amino acids for 2 hr, and 14CO2 formation was also measured. The amount of label taken up by octopus was uniformly 20‐25 per cent of that found for rat brain. The amount of 14CO2, however, differed according to the amino acid. Four times as much 14CO2 was generated from alanine by octopus optic lobe and twice as much by the vertical lobe than rat cortex, but from glutamate, only 24 per cent in the optic and 15 per cent in the vertical lobe. No 14CO2 was generated from [U‐14C]GABA in the octopus, by contrast with the rat.

(4) Activity of some of the enzymes involved in amino acid metabolism was determined in homogenates of rat cortex and octopus optic and vertical lobes, with and without activation by Triton X‐100. Enzymic activities in the octopus, with the exception of alanine aminotransferase, were lower than in the rat, and glutamate decarboxylase could not be detected in octopus brain, in the absence of detergent.
STUDIES ON THE LABELLING PATTERNS OF RNA FROM CEREBRAL CORTEX NUCLEI
Authors: Dutton G. R. , Campagnoni A. T. , Mahler H. R. , Moore W. J.
Published: October 2006

Abstract—

RNA labelling patterns in nuclei from rat cerebral cortex were investigated subsequent to intracerebral injection of [3H]uridine. Although there was a rapid uptake of label into the ‘heavy’ regions when nuclear RNA was analysed in density gradients, it was not possible to show conclusive evidence for 455 ribosomal precursor RNA. Methyl‐ation of 18S and 28S nuclear RNA became evident only after 2 hr and did not appear to involve the intermediacy of RNA species of higher molecular weight.
CARBOXYMETHYLATION OF SULPHYDRYL GROUPS IN PROTEOLIPIDS1
Authors: Lees Martorie B. , Leston J. A. , Marfey P.
Published: October 2006

Abstract—

(1) The sulphydryl groups of brain white matter proteolipids were studied by alkylation with iodoacetic acid and iodoacetamide in an organic solvent medium. To make sterically hindered sulphydryl groups available, the reaction was also carried out in the presence of sodium dodecyl sulphate.

(2) In all cases, iodoacetamide was a better alkylating agent than was iodoacetic acid.

(3) Only minimal alkylation of crude white matter proteolipids was obtained in the absence of detergent; addition of sodium dodecyl sulphate increased the availablity of SH groups.

(4) Purified proteolipids prepared by column chromatography were alkylated to a lesser degree than were crude proteolipids.

(5) Prior reduction with mercaptoethanol resulted in the quantitative conversion of cysteine to S‐carboxymethylcysteine with either alkylating agent and in both preparations.

(6) The possibility of a conformational difference between the protein in the crude and purified preparations is discussed.
STOFFWECHSELUNTERSUCHUNGEN DES CERE‐BRALEN ANFALLSGESCHEHENS
Authors: Wiechert P. , Göllnitz G.
Published: October 2006

Zusammenfassung— Die Aktivität der Glutaminase und Glutaminsynthetase sowie die Konzentration des freien Ammoniaks werden im Gehirn von Ratten während und vor cerebralen Anfällen bestimmt. Mit Einsetzen des Krampfes, nach i.e. Injektion von Pyridoxal‐5‐phosphat bereits in der Phase der sham rage, steigt die Aktivität der Glutaminase stark an. Der hierdurch bedingte erhöhte Substratumsatz führt zur Anhäufung von freier Glutaminsäure und Ammoniak im Hirngewebe. Diese Stoffwechselentgleisung ist möglicherweise eine weitere Ursache für das Entstehen cerebraler Anfälle.

Die Glutaminsynthetase ist am Zustandekommen der von uns untersuchten experimentellen Krampfanfälle nicht merklich beteiligt.

Die Konzentration des Ammoniaks ist sowohl in der präkonvulsiven als auch in der tonischen Phase des Krampfanfalls erhöht. Die beobachteten Veränderungen werden übereinstimmend mit anderen Autoren als Folge eines veränderten Stoffwechsels im erregten Nervengewebe angesehen, jedoch nicht als spezifisches oder auslösendes Merkmal cerebraler Anfälle.
TRIPHOSPHOINOSITIDE PHOSPHODIESTERASE IN DEVELOPING BRAIN OF THE RAT AND IN SUBCELLULAR FRACTIONS OF BRAIN
Authors: Keough K. M. W , Thompson W
Published: October 2006

Abstract— An assay system for the measurement of triphosphoinositide phosphodiesterase in homogenates of rat brain is described. With triphosphoinositide (TPI) as substrate, and in the presence of 0·1 m‐KCI and saturating amounts of diethyl ether, the activity of phosphodiesterase in myelinated brain was 400–500 μmoles of TPI hydrolysed per g wet wt. per hr. One quarter of the adult level of the enzyme was present in rat brain one day after birth, with the remainder being added prior to and during the early stages of myelination. On subfractionation of brain homogenates, substantial activity of the enzyme was located in the soluble portion and in the paniculate fractions enriched in myelin and synaptosomes. The enzyme associated with the particulate fractions could not be detached from the membranes by any of several methods employed. There was a rough correlation between distribution of phosphodiesterase and that of 5′‐nucleotidase, an enzyme associated with plasma membrane in a number of tissues. Some implications of the results are discussed.