bluuebunny/crossref_metadata_2025 huggingface dataset:
IN YOUR CAR NO ONE CAN HEAR YOU SCREAM! ARE TRAFFIC CONTROLS IN CITIES A NECESSARY EVIL?
Authors: Cassini Martin
Published: December 2006

Although widely accepted, traffic controls are an unnecessary evil, imposed on a road network by governments with no commercial incentive to ensure the free flow of traffic. Far from making our roads safer and less congested, traffic lights make matters worse. They take our eyes off the road, obstruct our progress and cause needless delay. In the process they damage our health, the economy and the environment. There is another way: remove controls and restore the common law principle of first‐come, first‐served – or ‘filter‐in‐turn’, as it's known in the Channel Islands. The optimum form of traffic control is self‐control. The onus should be on government to prove otherwise.
Trade Reorientation and Its Effects on Regional Port Systems: The Korea‐China Link along the Yellow Sea Rim
Authors: LEE JUNG‐YOON , RODRIGUE JEAN‐PAUL
Published: December 2006

ABSTRACT  Owing to its competitive labor costs, its open‐market policy, and a substantial amount of capital investments, China has become a global manufacturing pole and an export‐based economy replicating the conventional Asian model but on a much wider scale. This is creating acute competition on other Asian export‐based economies such as Korea that have to adapt to the “China effect.” Consequently, many Korean manufacturing companies have repositioned their capital and equipment in China to enlarge their market potential as well as to reduce their production costs. Because Korea is adjacent to China—both are sharing the Yellow Sea Rim—this shift is creating a unique geographical dimension with a high level of functional integration of Sino‐Korean manufacturing supply chains. This transition has also brought substantial changes in the regional logistic network by organizing new flows of raw materials, parts, and final products, most of them along the Yellow Sea Rim. New logistic flows have given substantial influences on regional port competition by creating diverse links. These changes are bringing a reorientation of the regional maritime industry and of the port system.
Rural migrant workers in urban China: living a marginalised life
Authors: Keung Wong Daniel Fu , Li Chang Ying , Song He Xue
Published: December 2006

The rural migrant worker population in China is attracting more and more attention because of its magnitude and potential economic and social impact on Chinese society. While literature abounds in describing the demographic trends and economic impacts of rural to urban migration, very few articles have been written about the psychosocial impacts of migration on the lives of rural migrant workers in urban China. Drawing on the concept of marginalisation, this article describes the nature and characteristics of marginalised living experienced by migrant workers. More importantly, it examines the underlying policy issues contributing to such marginalised living. It is argued that the Hukou system (household registration system), the process of decentralisation and the obscure role of trade unions have contributed to the experience of marginalisation of rural migrant workers in urban cities in China. Implications for policy changes are also discussed.
Studies of selection in vitro for novel resistance to phytotoxic products of Leptosphaeria maculans (Desm.) Ces. & De Not. in secondary embryogenic lines of Brassica napus ssp. oleifera (Metzg.) Sinsk., winter oilseed rape
Authors: NEWSHOLME DOROTHY M. , MACDONALD MARY V. , INGRAM D. S.
Published: December 2006

Culture filtrates of Leptosphaeria maculans (Desm.) Ces. & De Not. inhibited the germination of seeds of Brassica napus ssp. oleifera (Metzg.) Sinsk., winter oilseed rape. The toxicity of filtrates was broadly correlated with the pathogen icily of the isolates of L. maculans from which they were obtained, and the sensitivity of seeds of different cultivars was broadly correlated with the known resistances ot those cultivars to the fungus. Culture filtrates of B. maculans, when incorporated into culture media, were also toxic to secondary embryoids of B. napus ssp. oleifera, as also was Sirodesmin P.L., a putative pathotoxin of L. maculans. Variation for the ability to grow in culture in the presence of toxic levels of culture filtrate and Sirodesmin P. L. was detected among populations of secondary embryoids, and the proportion of resistant embryoids present in the population was increased by successive rounds of re‐selection on toxic, selective media. However, when embryoids were removed to non‐selective media, resistance to toxic culture filtrates and to Sirodesmin P.L. was rapidly lost. Plants regenerated from secondary embryogenic lines selected for resistance to toxic culture filtrate or Sirodesmin P.L. were no more resistant to infection by L. maculans then were plants regenerated from unselected, control secondary embryoids, and were consistently more susceptible than were plants grown from seed. It was concluded, firstly, that the rate of stable, heritable somatic variation may be insufficiently high in the secondary embryogenic lines to he of value in attempts to select in vitro for novel resistance to L. maculans secondly, that although the seed germination tests indicated that toxic culture filtrates may have potential as screening agents for detecting novel resistance to L. maculans in vitro, no evidence in support of this view was obtained in the experiments with secondary embryoids; and, finally, that because a relatively high level of resistance to L. maculans already exists in cultivars of H. napus ssp. oleifera, any novel variation m disease reaction that does occur m secondary embryogenic lines is likely to be towards greater susceptibility rather than increased resistance.
Interactions between hosts and non‐hosts of Pinus spp. and Matsucoccus josephi: anatomical responses of stem to infestation
Authors: LIPHSCHITZ NILI , MENDEL ZVI
Published: December 2006

Artificial infestation of seven pine species revealed that Matsucoccus josephi (Homoptera: Margarodidae) completes its development on Pinus brutia, P. eldarica and P. halepersis, whereas only a small number of the scale larvae infesting P. cunariensis and P. pined reached the second instar and none developed to the adult stage. M. josephi crawlers died while trying to feed on P. radiata and P. pinaster. Histological examination of the infested plant sections indicated that necrosis in shoot and stem barks of P. eldarica and P. halepensis occurs just before or after the scale completes its development. Injury reached the cambium, and traumatic resin ducts; parenchyma cells instead of tracheids and curved tracheids were formed. In P. brutia wound periderm was observed in the stem section but not in the shoot cortex following scale development. Wound periderm was also formed in the stem cortex of P. canariensis and P. pinena whereas no pathological changes were detected in the infested cortex of P. pinaster and P. radiata.

Mechanical lesions caused by needle punctures resulted in the production of parenchyma cells instead of tracheids in all four pine species investigated. The response of the pine cortex was non‐specific; however several similarities in the response to scale infestation, such as the formation of resin ducts, were observed. We hypothesize that the response of the pine tissue to the scale saliva is a hypersensitive reaction. It is suggested that the development of Matsucoccus species on particular pine species is related to the scale's inability to trigger the defence system of the host while the larvae are feeding.
Sequential response of whole plant water relations to prolonged soil drying and the involvement of xylem sap ABA in the regulation of stomatal behaviour of sunflower plants
Authors: ZHANG JIANHUA , DAVIES W. J.
Published: December 2006

Sunflower plants (Helianihus animus cv. Tall Single Yellow} were grown in the greenhouse in drain pipes (100 mm inside diameter and 1 m long) rilled with John Innes No. 2 compost. When the fifth leaf had emerged, half of the plants were left unwatered for 6 days, rewatered for 2 days and then not watered for another 12 days. Measurements of water relations and abaxial stomatal conductance were made at each leaf position at regular intervals during the experimental period. Estimates were also made of soil water potentials along the soil profile and of ABA concentrations in xylem sap and leaves.

Soil drying led to some reduction in stomatal conductance alter only 3 days but leaf turgors were not reduced until day 13 (6 days after rewatering). When the water relations of leaves did change, older leases became substantially dehydrated while high turgors were recorded in younger leaves. Leaf ABA content measured on the third youngest leaf hardly changed over the first 13 days of the experiment, despite substantial soil drying, while xylem ABA concentrations changed very significantly and dynamically as soil water status varied, even when there was no effect of soil drying on leaf water relations. We argue that the highest ABA concentrations in the xylem, found as a result of substantial soil drying, arise from synthesis in both the roots and the older leaves, and act to delay the development of water deficit in younger leases.

In other experiments ABA solutions were watered on to the root systems of sunflower plants to increase ABA concentrations in xylem sap. The stomatal response to applied ABA was quantitatively very similar to that to ABA generated as a result of soil drying. There was a log‐linear relationship between the reduction of leaf conductance and the increase of ABA concentration m xylem sap.
The mechanics of anchorage in seedlings of sunflower, Helianthus annuus L.
Authors: ENNOS A. ROLAND
Published: December 2006

Forces applied to plants will subject many of the roots to tension, which must be transferred to the soil via shear if uprooting is to be prevented. The stress distribution will depend on the relative stiffnesses of the earth and root, and the mode of failure will depend on the relative strength of the soil and of the root soil bond. This study of the anchorage of sunflower radicles combined uprooting tests performed by a tensile testing machine with mechanical tests on the roots and soil.

The maximum extraction force increased with length to an asymptotic value and was reached at a very low displacement. Root hairs and soil particles covered the tapered top 20 mm of extracted root, but the lower cylindrical region was bare. The soil was stiffer than the root, so shear stress was initially concentrated at the top of the root, soil strength over the top 20 mm resisting uprooting. Lower regions of the root were stressed later, their sparser root hairs being sheared off, and resist uprooting only by friction. In a further lest upper and lower regions of radicles were uprooted separately. As predicted, the upper region generated much greater resistance to uprooting per unit length, and at much lower displacements than the lower region.

The top of the radicle is well adapted for anchorage, the profuse root hairs and mucigel it produces glueing the root to the soil. The lower regions are thus protected from damage.
The effects of culture medium rigidity on adventitious bud production and tissue vitrification in needle cultures of Sitka spruce [Picea sitchensis (Bong.) Carr.]
Authors: SELBY C. , LEE R. , HARVEY B. M. R.
Published: December 2006

Adventitious bud formation on Sitka spruce [Picca sitchensis (Bong.) Carr.] needle explants was strongly dependent upon the rigidity of the culture medium. In general, of organogenesis was greatest on weak gels and poorest on more rigid gels resulting from increased medium pH or agar strength. There was a significant interaction between agar strength and pH, with the optimum pH for organogenesis declining with increasing agar strength. Poor organogenesis at high agar concentrations was not due to toxic impurities since increased adventitious bud production could be stimulated by decreasing the medium pH whilst maintaining a high agar strength and an agar washing treatment had no significant effect. Although high levels of organogenesis could be sustained on weak gels the resultant adventitious shoots often showed severe vitrification. The frequency of shoots showing vitrification could be reduced by growing the tissues on harder media but this resulted in reduced shoot elongation. Vitrification of needle tissues did not stimulate the formation of adventitious buds in the absence of cytokinins.
The effects of aluminium and Paxillus involutus Fr. on the growth of Norway spruce [Picea abies (L.) Karst.]
Authors: WILKINS D. A. , HODSON M. J.
Published: December 2006

Norway spruce [Picea aides (L.) Karst.] seed lots were obtained from populations growing on an acid soil in the Black Forest, West Germany (acid), and a calcareous soil in the Schwabische Alb, West Germany (calc). Seedlings were grown in sterile perlite culture containing 0–6 mM aluminium. Hypocotyl extension was inhibited by aluminium in the calcareous seedlings, hut not in the acidic seedlings. In a longer term experiment acidic and calcareous plants were grown for 10 weeks in perlite. Some of the tubes were inoculated with the fungus Paxillus involutus Fr. (designated F +) and some were not (F ‐). Aluminium sulphate solutions were then added to the tubes to raise the aluminium concentrations to 0–6 mM. Plants were harvested after a further 10 weeks. Fungus was associated with the roots in F+ plants, but mycorrhizas did not form. Growth of acid(F ‐) was somewhat stimulated by aluminium treatment, but that of calc(F ‐) was greatly reduced, and the plants were chlorotic. The presence of a rhizospherie fungus (F +) enhanced the growth of the calcareous plants, but had little effect on the acidic plants. Shoot analyses suggested that the greater aluminium sensitivity of the calcareous plants involves an inability to exclude aluminium or to maintain normal levels of calcium and magnesium uptake in its presence. The presence of rhizospheric fungi reduced the effects of aluminium.
FEEDBACK CONTROL OF RAT BRAIN 5‐HYDROXYTRYPTAMINE SYNTHESIS1
Authors: Macon J. B. , Sokoloff L. , Glowinski J.
Published: December 2006

Abstract— The effect of increased levels of 5‐hydroxytryptamine (5‐HT) on the synthesis of [3H]5‐HT from intracisternally injected tracer doses of [3H]tryptophan was studied in the rat brain stem. The [3H]5‐HT which accumulated in the first 15 min after [3H]tryptophan injection was measured at various times after the acute intraperitoneal administration of the monoamine oxidase inhibitors Catron or Pargyline. The 5‐HT levels reached two and three times control values respectively at 20 min and 180 min after monoamine oxidase inhibitor administration but [3H]5‐HT accumulation was decreased (40 per cent) at 180 min when compared with 20 min. These data as well as those obtained after chronic treatment with monoamine oxidase inhibitors revealed that there is an inverse relationship between [3H]5‐HT accumulation and the endogenous 5‐HT level. Monoamine oxidase activity was undetectable during all the intervals in which [3H]5‐HT accumulation was measured. No inhibition of [3H]5‐HT accumulation was detected when [3H]5‐hydroxytryptophan was injected instead of [3H]tryptophan. The results are consistent with a negative feedback of 5‐HT synthesis at the rate‐limiting tryptophan hydroxylation step.
METAL CHELATES IN THE STORAGE AND TRANSPORT OF NEUROTRANSMITTERS: INTERACTIONS OF METAL IONS WITH BIOGENIC AMINES1
Authors: Rajan K. S. , Davis J. M. , Colburn R. W.
Published: December 2006

Abstract— Equilibrium studies on the interaction of biogenic amines with iron (Fe2+ and Fe3+) and magnesium (Mg2+) were undertaken in an attempt to correlate the stabilities of metal‐amine chelates and the reported granule‐binding affinities of the biogenic amines. By means of potentiometric equilibrium measurements at 25°C and an ionic strength of 10 (KNO3) the formation constants of the Fe2+ chelates with norepinephrine (NE) and adenosine‐S‐triphosphate (ATP) were determined. Possible structures were derived for the co‐ordinate binding of Fe2 + with NE. The interactions of Fe2+ and Fe2+‐ATP with NE were investigated and the formation of Fe2+‐NE‐ATP (1:1:1) mixed ligand ternary chelate was proposed on the basis of the equilibrium data. Information obtained from chelation studies of Fe2+ with pyrocatechol and ethanolamine taken together with the data obtained on the Fe2+‐NE system indicated that the binding of Fe2+ by NE was probably via the pyrocatechol moiety. Equilibrium constants for the binding of tyramine (TA) dopamine (DA) and NE with Mg2+ were also determined. The equilibrium data obtained on the Mg2+‐amine systems indicated a correlation between the metal‐amine binding affinities and the structure and amine‐release (and storage) activities of the biogenic amines. A consideration of the stabilities of the Fe2+ and Mg2+ chelates together with the occurrence of these metal ions in synaptosomes suggests their possible involvement in the intra vesicular amine‐binding and storage sites.
HISTOCHEMISTRY OF MYELIN—XII ANIONIC STAINING OF MYELIN BASIC PROTEINS FOR HISTOLOGY, ELECTROPHORESIS AND ELECTRON MICROSCOPY
Authors: Adams C. W. M. , Bayliss O. B. , Hallpike J. F. , TURNER D. R.
Published: December 2006

Abstract— Phosphotungstic acid haematoxylin, trypan blue and amidoblack techniques have been developed as anionic dye methods for staining myelin basic proteins. All methods displayed central and peripheral nervous system myelin in histochemical prepa rations and stained brain basic proteins in electrophoretic polyacrylamide gels: phosphotungstic acid haematoxylin appeared to be the most selective of these techniques. Electron photomicrographs of peripheral nerve stained by phosphotungstic acid haematoxylin showed that the major part of myelin basic protein is located in the period dense line. The basic proteins stained by phosphotungstic acid haematoxylin showed an early loss in rat sciatic nerve undergoing Wallerian degeneration and had completely disappeared from the centre of 20 plaques of multiple sclerosis.
GLYCOSYL TRANSFERASES OF MICROSOMAL FRACTIONS FROM BRAIN: SYNTHESIS OF GLUCOSYL CERAMIDE AND GALACTOSYL CERAMIDE DURING DEVELOPMENT AND THE DISTRIBUTION OF GLUCOSE AND GALACTOSE TRANSFERASE IN WHITE AND GREY MATTER1
Authors: Shah S. N.
Published: December 2006

Abstract— The substrate specificity for glycosyl transferases of microsomal fractions from brain was investigated. Ceramides were found to be better acceptors than sphingosine for both glucose and galactose when a Celite dispersion of lipid substrate was used. For galactose transfer only hydroxy fatty acid ceramide served as an acceptor. For transfer of glucose both non‐hydroxy and hydroxy fatty acid ceramide served as acceptors, but the hydroxy fatty acid ceramide was the more effective of the two. Glucose transferase activity was found to be highest between birth and 15 days of age and declined slowly with later development. Galactose transferase activity did not appear until the 10th day of postnatal age and reached a peak at about the 30th day. Galactose transferase activity was present principally in white matter microsomes, but glucose transferase activity was present in the microsomal fractions of both white and grey matter. The developmental alteration in the activities of galactosyl and glucosyl transferases and their distribution in white and grey matter correlated with development and distribution of cerebroside and ganglioside, respectively.
EFFECT OF STRESS ON THE DISPOSITION OF CATECHOLAMINES LOCALIZED IN VARIOUS INTRANEURONAL STORAGE FORMS IN THE BRAIN STEM OF THE RAT
Authors: Thierry A. M. , Blanc G. , Glowtnski J.
Published: December 2006

Abstract— The utilization of [3H]norepinephrine newly taken up or newly synthesized from [3H]tyrosine was studied in the brain stem of normal and stressed rats up to 5 h after the intracistemal injection of [3H]norepinephrine or [3H]tyrosine. The biphasic disappearance of the exogenous as well as of the endogenously synthesized [3HJnorepinephrine revealed that the amine is localized in at least two main compartments (A and B). The half‐life of the amine newly taken up or newly synthesized, mainly localized in compartment A, is of short duration (between 15 and 30 min); the amine stored for a longer period of time and mainly distributed in compartment B is utilized more slowly (half‐life, 180 to 260 min). A stress of short duration (15 min) induced by electric shocks applied to the feet increased the utilization of [3HJnorepinephrine newly taken up or newly synthesized from [3H]dopamine or [3H]tyrosine, but has no effect on the [3H]norepinephrine stored for a longer time period, indicating that the amine in compartment A is released in preference to that stored in compartment B. A stress of longer duration (180 min) increased the utilization of [3H] norepinephrine in both compartments and induced a sustained increased in norepinephrine synthesis as shown by the enhanced formation of [3H]norepinephrine from [3H]tyrosine in brain stem slices in vitro. The electrical stress was without effect on [3H]norepinephrine uptake. As for [3H]norepinephrine, the 15 min of stress enhanced the utilization of [3H] dopamine newly taken up or newly synthesized from [3H]tyrosine and had no effect on [3H]dopamine stored for a longer time period. These results suggest an increased release of both [3H]dopamine and [3H]norepinephrine from noradrenergic terminals of the rat brain stem. Finally, the 15 min of stress appeared to have no effect on the utilization of [3H] serotonin newly synthesized from [3H]tryptophan in serotonergic neurons of the brain stem, whereas the 180 min of stress increased the utilization of 5‐HT in this structure.
DISC ELECTROPHORETIC SEPARATION OF PROTEINS IN NEURONAL, GLIAL AND SUBCELLULAR FRACTIONS FROM CEREBRAL CORTEX
Authors: Packman P. M. , Blomstrand C. , Hamberger A.
Published: December 2006

Abstract— Soluble proteins were studied in preparations from rabbit brain cortex enriched in neuronal or glial cells and in subcellular cortical fractions. Analytical polyacrylamide gels were used for acidic (pH 9‐5) and basic (pH 4‐3) proteins and qualitative and quantitative differences are described. The isozymes of lactic dehydrogenase, brain specific proteins and radioactive labelling patterns were used to characterize some soluble proteins.
DEVELOPMENTAL PROFILES OF GANGLIOSIDES IN HUMAN AND RAT BRAIN
Authors: Vanier M. T. , Holm M. , ÖHman R. , Svennerholm L.
Published: December 2006

Abstract— The developmental profiles of individual gangliosides of human brain were compared with those of rat brain. Interest was focused mainly on the pre‐ and early postnatal development. Human frontal lobe cortex covering the period from 10 foetal weeks to adult age and the cerebrum of rat from birth to 21 days were analysed. Lipid‐NANA and lipid‐P were followed; in the rat, also protein and brain weight. A limited number of samples of human cerebral white matter and cerebellar cortex were also studied. The following major results were obtained:

The ganglioside concentration increased approximately three‐fold within a short period: in rat cerebrum, from birth to the 17th day; in human cerebral cortex, from the 15th foetal week to the age of about 6 months. The largest increase in the rat brain occurred by the 11th to the 13th day; in human brain by term. The relative increase of gangliosides during this period was more rapid than that of phospholipids.

A hitherto unknown distinct early period of ganglioside and phospholipid formation in rat occurred by the second to fourth day.

The changes in brain ganglioside pattern, characteristic of the developmental stages of the rat, were found to be equally pronounced in the human brain.

Regional developmental differences in the ganglioside pattern were demonstrated in human brain. A characteristic white matter pattern, rich in monosialogangliosides, had developed by the age of 1 year. The increase in ganglioside concentration and the formation of the definitive ganglioside pattern of cerebellar cortex occurred later than in cerebral cortex. This cerebellar pattern was characterized by a very large trisialoganglioside fraction.

The two periods of rapid ganglioside metabolism in rat brain preceded the two periods of rapid protein biosynthesis.
FRACTIONATION OF THE RNA COMPONENTS OF RAT BRAIN POLYSOMES
Authors: Campagnoni A. T. , Dutton G. R. , Mahler H. R. , Moore W. J.
Published: December 2006

Abstract—The incorporationin vivoof [3H]uridine into the RNA isolated from the free polyribosomes of rat cerebral cortex was studied. Sedimentation in sucrose gradients showed that initially (at times less than 60 min after injection of precursor) the label was associated with a heterodisperse species, while at longer times there was an increased coincidence of label with stable rRNA. Further fractionation was accomplished by means of differential extraction with phenol and analysis on polyacrylamide‐agarose gels. Most of the rapidly labelled RNA was concentrated in a fraction obtained at pH 8‐3 and 40°C. The base composition of this fraction differed greatly from that of rRNA, preribosomal RNA and DNA. Analysis by electrophoresis on polyacrylamide‐agarose gels showed it to be composed of several distinct species in addition to residual 18 and 28S rRNA. Most of the latter was concentrated in a fraction extracted at pH 60 at 0°C.
THE REGIONAL DISTRIBUTION, AGE DEPENDENT VARIATION AND SPECIES DIFFERENCES OF BRAIN ARYLSULPHATASES
Authors: Farooqui A. A. , Bachhawat B. K.
Published: December 2006

Abstract— The relative proportions of arylsulphatase A and B were determined by the method of Baum, Dodgson and Spencer (1959) in brains of various animal species and it was found that there was a considerable variation in the concentration of these two enzymes.

Arylsulphatase A and B of various animal species including rat, man, monkey, sheep and chicken were partially separated using zinc acetate fractionation procedure and gel electrophoresis. The chicken brain arylsulphatase A had a similar electrophoretic mobility to that of arylsulphatase B of other species. Further, chicken brain arylsulphatase A precipitated at a zinc acetate concentration of 0005 M, a condition under which arylsulphatase B from the brain of other species precipitated.

Kinetic properties such as Km value and inhibitory effect of sulphite and phosphate ions indicated that chicken brain arylsulphatase A was similar to arylsulphatase A of other species.

The results on regional distribution of arylsulphatase A and B activities in monkey brain and in developing rat brain suggest a relationship between arylsulphatase A and sulphatides and arylsulphatase B and mucopolysaccharides.
THE INFLUENCE OF TYROSINE, PHENYLPYRUVATE AND VITAMIN B6 UPON SEIZURE THRESHOLDS 1
Authors: Gallagher B. B.
Published: December 2006

Abstract— Thresholds to the first appearance of a myoclonic jerk and to the appearance of tonic‐clonic seizures induced by the convulsant, hexafiuorodiethyl ether, were examined in immature rats at sequential time intervals following the administration of L‐tyrosine, L‐phenylalanine, Na‐phenylpyruvate and several forms of vitamin B6. l‐Tyrosine failed to lower either seizure threshold even though plasma and brain levels of tyrosine exceeded those obtained with a dose of phenylalanine that was effective in lowering threshold. Na‐phenylpyruvate lowered both seizure thresholds at a time that correlated with elevation of brain phenylalanine. Pyridoxine hydrochloride, pyridoxal‐5′‐phosphate and pyridoxamine phosphate all lowered both seizure thresholds. The time course and dose dependency of the effects of B6 vitamers were examined; the effect of phenylalanine on seizure threshold was unrelated to derived tyrosine or phenylpyruvate and vitamin B6 was not involved. The enhanced cerebral excitability following administration of B6 vitamers is discussed.
NEUROCHEMISTRY OF THE SPINAL CORD IN EXPERIMENTAL BORDER DISEASE (HYPOMYELINOGENESIS CONGENITA) OF LAMBS
Authors: Patterson D. S. P. , Terlecki S. , Done J. T. , Sweasey D. , Hebert C. Nancy
Published: December 2006

Abstract— The total lipid, cholesterol (free and esterified), cerebroside, phospholipid and fat‐free dry matter contents were estimated in spinal cords of lambs affected with experimentally produced Border Disease. Comparisons were made with a healthy control group and with a group of lambs obtained from vaccinated ewes.

Clinically affected lambs showing tremors ('shaking’), a‘hairy’birthcoat or both were found to possess one or two myelin lipid abnormalities. These were a generalised deficiency of myelin lipids (notably cerebroside) and the presence of abnormal quantities of esterified cholesterol. The former was particularly associated with the birthcoat defect and the latter with the neurological signs.

Previous exposure of the ewes to the infective agent (vaccination 28 days before mating) appeared to give considerable protection against the degenerative lipid changes and against 'shaking’but less against myelin dysgenesis and‘hairiness’.
PATTERNS AND LABELLING CHARACTERISTICS IN NEURONAL AND GLIAL RNA
Authors: Jarlstedt J. , Hamberger A.
Published: December 2006

Abstract— Rabbit cortex slices were incubated in a medium containing [3H]‐uridine for various periods of time. Following incubation, neuronal and glial cell fractions were prepared on a discontinuous Ficoll‐sucrose gradient. RNA was extracted from neurons and glia with a tris‐sodium dodecyl sulphate‐phenol solution and fractionated on a composite agarose‐polyacrylamide gel. The stained gel showed major bands corresponding to 28 s, 18 s, 5 s and 4 s fractions and additional minor bands at the position of 24 s, 21 s and 13 s. Neuronal and glial RNA had the same general RNA pattern but the 5 s fraction was more pronounced in neuronal RNA and 4 s more pronounced in glial RNA. After 30 min labelling both neuronal and glial RNA had maximum activities in fractions higher than 28 s with a peak corresponding to 45 s. In the lower mol. wt. region the labelling was essentially poly‐disperse. With increasing incubation time, peaks corresponding to 38 s and 32 s appeared as well as to ribosomal and soluble fractions. Incorporation of activity into total RNA expressed as d.p.m/μg of nucleic acids, showed similar labelling in neurons and glia after 30 and 60 min and a 3‐4 times higher incorporation into neuronal RNA after 180 min. The possible implications of these results are discussed.
LEVELS OF 5‐HYDROXYTRYPTAMINE, DOPAMINE AND NOREPINEPHRINE IN WHOLE BRAIN OF RABBITS IN CHRONIC MANGANESE TOXICITY
Authors: Mustafa S. J. , Chandra Satya V.
Published: December 2006

Abstract— The levels of 5‐Hydroxytryptamine (5‐HT), dopamine and norepinephrine were estimated in whole brain of rabbits inoculated intratracheally with manganese dioxide (400 mg). Twenty one and 58 per cent lowering in the concentrations of dopamine and norepinephrine, respectively, were observed as compared to that of controls, the concentration of 5‐HT was found to be unaltered.
STANDARDIZATION OF A RADIOCHEMICAL ASSAY OF CHOLINE ACETYLTRANSFERASE AND A STUDY OF THE ACTIVATION OF THE ENZYME IN RABBIT BRAIN
Authors: Bull G. , Oderfeld‐Nowak Barbara
Published: December 2006

Abstract—

The standardization of a radiochemical assay of choline acetyltransferase (acetyl‐CoA: choline‐O‐acetyltransferase EC 2.3.1.6. [ChAc]) is described. The method depends upon the use of [l‐C14]acetyl‐CoA as substrate and has been modified from the procedure originally published by MCCAMAN and HUNT (1965).

The modified method gave results which were comparable with two methods depending on bioassay as the end step, which had previously given the highest recorded values for rabbit brain ChAc.

Methods of extraction and activation of the enzyme were also investigated. The results showed that ether‐treated sucrose homogenates and cysteine‐saline extracts of acetone‐dried brain have comparable enzyme activities; both procedures give higher values than are obtained with untreated water homogenates, or sucrose homogenates treated with Nonex 501 or Triton X‐100.
CIRCULAR DICHROISM AND VISCOMETRIC STUDIES ON A BASIC PROTEIN FROM PIG BRAIN 1
Authors: Kornguth S. E. , Perrin J. H.
Published: December 2006

Abstract— A highly purified basic protein prepared from pig brain was studied by circular dichroism and viscometry. The circular dichroism spectrum of the protein in 50% (v/v) aqueous n‐propanol showed two negative bands (at 217‐220 nm and 204 nm); the spectrum in 90% (v/v) aqueous trifluoroethanol similarly showed two negative bands (at 217 nm and at 206 nm). The molar ellipticity of this protein in aqueous solvents was relatively flat and no negative bands were observed above 200 nm. The ηap C of the protein from pig brain was 0‐12 as C → O in tris buffer (0‐1 M, pH 7‐8). On the basis of these studies we concluded that the protein is asymmetric and extended in aqueous systems and contains a maximum of 20 per cent α‐helix in trifluoroethanol.
STUDIES IN VIVO ON THE RELATIONSHIP BETWEEN BRAIN TRYPTOPHAN, BRAIN 5‐HT SYNTHESIS AND HYPERACTIVITY IN RATS TREATED WITH A MONOAMINE OXIDASE INHIBITOR AND L‐TRYPTOPHAN
Authors: Grahame‐Smith D. G.
Published: December 2006

Abstract— The effect of l‐tryptophan loading upon the amount of 5‐HT accumulating in the brains of rats pretreated with a monoamine oxidase inhibitor was studied. The amount of brain 5‐HT accumulated increased with increasing tryptophan dosages and brain tryptophan concentrations up to a tryptophan dose of 120 mg/kg body wt. and a brain tryptophan of about 70 μg/g brain. Above this dose and concentration no further increase in brain 5‐HT accumulation occurred. After monoamine oxidase inhibition and tryptophan loading gross hyperactivity and hyperpyrexia occurred. Monoamine oxidase inhibition, tryptophan administration and intact aromatic amino acid decarboxylase activity were all collectively essential for the production of hyperactivity and hyperpyrexia. DL‐Parachlorophenyl‐alanine prevented both the occurrence of hyperactivity and the increased accumulation of, brain 5‐HT. Indices of hyperactivity correlated with the amount of brain 5‐HT accumulating in 1 h after tryptophan loading but not with the overall concentration of brain 5‐HT, suggesting that hyperactivity was dependent upon the rate of 5‐HT synthesis. Reserpine and tetra‐benazine pretreatment speeded the onset and rate of development of the hyperactive state without altering the synthesis of brain 5‐HT. It is suggested that when monoamine oxidase is inhibited and the rate of 5‐HT synthesis is increased, granular uptake and storage of 5‐HT and other rate‐limiting mechanisms for 5‐HT inactivation are unable to prevent 5‐HT 'spilling over’to produce hyperactivity.

The crucial dependence of 5‐HT synthesis upon brain tryptophan concentration and the ability of intraneuronal metabolism, when monoamine oxidase activity is intact, to cope with increased 5‐HT synthesis and prevent ‘spillover’, raise the possibility that brain 5‐HT synthesis is normally in excess of functional needs, and suggest that intraneuronal metabolism and the intraneuronal organization of 5‐HT pools are of more importance than synthesis in regulating the amount of 5‐HT available for functional activity.
EXTRACTION, PURIFICATION AND TURNOVER OF RAT BRAIN GLYCOGEN
Authors: Strang R. H. C. , Bachelard H. S.
Published: December 2006

Abstract— Glycogen was prepared from rapidly frozen rat brain by the usual techniques and found to contain considerable amounts of non‐glycogen carbohydrate. The crude glycogen was partially purified by extraction with hot or cold water and reprecipitation. Enzymic estimation showed that the carbohydrate extracted into hot water contained only 50 per cent of glucose after hydrolysis; of the hot water insoluble material, namely some 30 per cent of the total carbohydrate present in the crude glycogen, less than half of the carbohydrate was released by hydrolysis in 1 M‐HC1. The glycogen soluble in hot water incorporated 14C from [14C]glucose at considerably higher rates than the residual material and also decreased more rapidly during post‐mortem autolysis. Glycogen extracted into cold water was of higher purity than that extracted by hot water; although the material behaved as glycogen during precipitation and re‐extraction it contained only 75 per cent of its carbohydrate as glucose. Contaminants included fucose, galactose and hexuronic acid. The rates of metabolism of the partially purified glycogen are compared with published rates; it is suggested that the observed rates are inaccurate due to the impurities present in brain glycogen prepared by classical techniques.
METABOLIC CONSEQUENCES OF ETHANOL OXIDATION IN BRAINS FROM MICE CHRONICALLY FED ETHANOL
Authors: Rawat A. K. , Kuriyama K. , Mose Josephine
Published: December 2006

Abstract— Effects of the acute and chronic administration of ethanol have been investigated in mouse brain on the redox‐state, citric acid cycle function, levels of adenine nucleotides and other metabolites. Cerebral oxidation of ethanol, activity of alcohol dehydrogenase and the permeability of brain and liver mitochondrial preparations after chronic ethanol administration have been also investigated. Acute or chronic administration of ethanol resulted in a small but significant increase in the reduced components of certain dehydrogenase‐linked substrate pairs in brain. Pyrazole, an inhibitor of alcohol dehydrogenase, prevented the ethanol‐induced changes in brain. 14CO2 production from several substrates was inhibited in brains from chronically ethanol‐fed animals. Addition of pyrazole, however, prevented the ethanol‐mediated inhibition of 14CO2 production. Chronic administration of ethanol resulted in decreased levels of ATP and creatine phosphate in the brain, and increased contents of ADP and AMP. The cerebral activities of alcohol dehydrogenase and succinic dehydrogenase, oxidation of ethanol, mitochondrial oxidation of a‐glycerophosphate, and levels of NADH remained unaffected by the chronic administration of ethanol. In contrast to liver, where chronic administration of ethanol increased the contribution of 'substrate shuttles’resulting in increased oxidation of ethanol; in brain, the contribution of these 'shuttles’remained unaffected.
A SOLUBLE PREPARATION FROM RAT BRAIN THAT INCORPORATES INTO ITS OWN PROTEINS [14C]ARGININE BY A RIBONUCLEASE‐SENSITIVE SYSTEM AND [14C]TYROSINE BY A RIBONUCLEASE‐INSENSITIVE SYSTEM
Authors: Barra H. S. , Rodriguez J. A. , Arce C. A. , Caputto R.
Published: December 2006

Abstract— A 100,000 g supernatant fraction from rat brain that was passed through a column of Sephadex G‐25‐40 was able, after addition of some factors, to incorporate [I4C]arginine (apparent Km= 5 μM) and [14C]tyrosine (apparent Km= 20 μM) into its own proteins. The factors required for the incorporation of [14C]arginine were: ATP (optimal concentration = 0‐25‐2 μM) and Mg2+ (optimal concentration 5 mM). For the incorporation of [I4C]tyrosine the required factors were: ATP (apparent Km= 0‐75 μM), Mg2+ (optimalconcentration 8‐16 mM) and K+ (apparent Km= 16 mM). Addition of 19 amino acids did not enhance these incorporations. Optimal pHs were: for [14C]arginine and [14C]tyrosine, respectively, 7‐4 and 7‐0 in phosphate buffer and 7–9 and 7‐3‐8‐1 in tris‐HCl buffer. Pancreatic ribonuclease abolished the incorporation of [14C]arginine but had practically no effect in the incorporation of [14C]tyrosine. Furthermore, [14C]arginyl‐tRNA was a more effective donor of arginyl groups than [14C]arginine, whereas [14C]tyrosyl‐tRNA was considerably less effective than [14C]tyrosine. The incorporations of [14C]arginine and [14C]tyrosine into brain proteins were from 25‐ to 2000‐fold higher than for any other amino acid tested (12 in total). In brain [14C]arginine incorporation was higher than in liver and thyroid but somewhat lower than in kidney. In comparison to brain, the incorporation of [14C]tyrosine was negligible in liver, thyroid or kidney. Kinetic studies showed that the macromolecular factor in the brain preparation was complex. The protein nature of the products was inferred from their insolubilities in hot TCA and from the action of pronase that rendered them soluble. [14C]Arginine was bound so that its a‐amino group remained free. Maximal incorporation of [14C]tyrosine in brain of 30‐day‐old rats was about one‐third of that in the 5‐day‐old rat. The changes with postnatal age in the incorporation of [14C]arginine were not statistically significant.
ENZYMES OF ENERGY‐CONVERTING SYSTEMS IN INDIVIDUAL MAMMALIAN NERVE CELL BODIES1
Authors: Kato T. , Lowry O. H.
Published: December 2006

Abstract— The activities of 7 enzymes (hexokinase, phosphofructokinase, glucose‐6‐P dehydrogenase, 6‐P‐gluconic dehydrogenase, NADP linked isocitric dehydrogenase, malic dehydrogenase and lactic dehydrogenase) were measured in individual nerve cell bodies of 8 different neuronal types: pyramidal cells from cerebral cortex and Amnion's horn, Purkinje cells, giant cells in the reticular formation, Deiters’nucleus cells, facial nucleus cells, anterior horn cells and dorsal root ganglion cells. Samples of similar size were analysed from the molecular layer of cerebellum.

The cell bodies were dissected from frozen‐dried tissue sections and weighed on quartz fibre balances. The weights ranged from 0–2 ng for the smallest pyramidal cells to 9 ng for the largest giant cells. The specific enzymatic reactions were carried out in small volumes (0–01–5 μl) under mineral oil (‘oil‐well technique’). The NADPH2 or NAD formed was amplified by‘enzymatic cycling’and measured fluorometrically. A new cycling method was used for measuring the NAD formed in three of the enzymatic methods. Double cycling was used to measure glucose‐6‐P and 6‐P‐gluconate dehydrogenases in the smallest cell bodies.

Each type of neuron exhibited a unique enzyme pattern, but four general patterns could be distinguished. The most variable of the enzymes was glucose‐6‐P dehydrogenase which was nearly 10‐fold higher in anterior horn cells than in pyramidal cells from the cerebral cortex. Malic dehydrogenase was the most constant, with a 3‐fold range from the highest (Purkinje cells) to the lowest (dorsal root ganglion cells).
RNA AND DNA IN DEVELOPING RETINAE: COMPARISON OF A NORMAL WITH THE DEGENERATING RETINAE OF C3H MICE1
Authors: Lolley R. N.
Published: December 2006

Abstract— The Nucleic acids were measured in developing retinae of normal (DBA) mice and those afflicted with an inherited degenerative disease (C3H). The content of RNA in normal and C3H retinae increased to a maximum at 5 days of postnatal age. Thereafter, that of C3H retinae declined to a value lower than the normal. The content of DNA in normal and C3H retinae was maximal at 10 and 5 days of postnatal age, respectively. By 20 days, it declined in both retinae to nearly adult values. The DNA/RNA ratio of normal adult retinae was about 3, while that of C3H adult retinae was nearly 1–5. It is proposed that the photoreceptor cells possess a smaller cytoplasmic volume and a larger DNA/RNA ratio than the cells of the inner retina. The loss of DNA in developing normal and C3H retinae appears to result from cellular death. It was calculated that approximately 1 million cells in normal and 6 million cells in C3H retinae disappear during development. Cellular death in C3H retinae may not be restricted to the photoreceptor population.
FREEZE‐BLOWING: A NEW TECHNIQUE FOR THE STUDY OF BRAIN IN VIVO
Authors: Veech R. L. , Harris R. L. , Veloso D. , Veech E. H.
Published: December 2006

Abstract— A new apparatus is described which removes and freezes brains of conscious rats more rapidly than was heretofore possible. The apparatus consists of two probes which are driven simultaneously into the cranial vault of the rat immobilized in a specially constructed restraining cage. When in position, air under pressure enters through one probe and blows the supratentorial portion of the brain tissue (situated between the olfactory bulbs and the superior colliculi) out the other probe and into a thin chamber previously cooled in liquid N2. This method stops brain tissue metabolism more rapidly than the previously‐described methods of microwave irradiation, decapitation into liquid N2, or whole‐animal immersion into liquid N2, as evidenced by the measurement of labile metabolites and redox states. Thus, samples of freeze‐blown brain had higher levels of a‐oxoglutarate, creatine phosphate, pyruvate, glucose and glucose‐6‐phosphate and lower levels of lactate, malate and AMP than brain tissue obtained by the other methods. The free cytoplasmic [NAD+]/[NADH2], [NADP+]/[NADPH2] and [ATP]/[ADP] [HPO42‐] ratios were higher in freeze‐blown samples. These data indicate that more extensive anoxic metabolism occurred when methods other than freeze‐blowing were used. We conclude that the levels of metabolites measured in brain obtained with the freeze‐blowing technique more closely resemble those which occur in vivo.
PYRUVATE METABOLISM BY HOMOGENATES OF HUMAN BRAIN: EFFECTS OF PHENYLPYRUVATE AND IMPLICATIONS FOR THE ETIOLOGY OF THE MENTAL RETARDATION IN PHENYLKETONURIA
Authors: Patel M. S. , Grover W. D. , Auerbach V. H.
Published: December 2006

Abstract— The effect of phenylalanine and phenylpyruvate on the metabolism of pyruvate by homogenates of human brain was investigated. In the presence of 5 mM pyruvate as substrate homogenates of human cerebral cortex fixed about 1 μmol of H14CO3‐‐ per g of tissue in 30 min. Phenylpyruvate at a concentration of 5 raw inhibited the fixation of H14 CO3‐‐ by homogenates of human brain by approximately 50 per cent, whereas 5 mM phenylalanine had no effect. The inhibition of pyruvate carboxylation by phenylpyruvate was dependent upon the concentration of the inhibitor. The activity of pyruvate carboxylase (EC 6.4.1.1) in human cerebral cortex was 02–0.4 units, with a Km for pyruvate of about 0.2 mM. Homogenates of human cerebral cortex decarboxylated [1‐14C]pyruvate to 14CO2 at a rate of about 5 μmol per g of tissue per 15 min, with a 20–50 per cent reduction in the presence of 5 mM phenylpyruvate; phenylalanine at the same concentration had no effect. The possible toxic effect of phenylpyruvate on the metabolism of pyruvate in the brains of untreated phenylketonuric patients is discussed.
GABA UPTAKE IN RAT BRAIN SLICES: INHIBITION BY GABA ANALOGUES AND BY VARIOUS DRUGS
Authors: Beart P. M. , Johnston G. A. R.
Published: December 2006

Abstract— 2‐Hydroxy‐, 2‐chloro‐, 2‐ and Cmethyl‐GABA are linear competitive inhibitors of GABA uptake in rat brain slices. These analogues are thus potential substrates for the GABA transport system and possible‘false transmitters'. 2‐Hydroxy‐GABA is the most potent inhibitor of GABA uptake yet described. No specific inhibitor of GABA uptake was revealed amongst the drugs tested.