bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of pH of Fermentation Medium on Biosynthesis of Poly[(3‐hydroxybutyrate)‐co‐(3‐mercaptopropionate)] by Wautersia eutropha
Authors: Isemori Yuichi , Tajima Koichiro , Tanaka Syogo , Yu Fang , Ishida Kazuki , Inoue Yoshio
Published: October 2006

Summary: A series of P(3HB‐co‐3MP)s with different 3MP unit content was biosynthesized by the fermentation of W. eutropha in a medium containing sodium gluconate and DTDP as carbon sources at different pH conditions ranging from pH 6.0 to 8.0. The P(3HB‐co‐3MP) samples were fractioned using the solvent/nonsolvent mixed solvent chloroform/heptane and the comonomer unit composition was investigated. It was found that W. eutropha produces P(3HB‐co‐3MP)s with extremely different 3MP unit content ranging from 3.6 to 70.0 mol‐%, depending on the pH value of the fermentation medium. The copolyester samples produced in mild basic medium have a considerably narrower compositional distribution than the samples from acidic medium. The highest polymer yield was obtained at pH 8.0.

DSC diagram for P(3HB‐co‐3MP)s biosynthesized in different pH medium.

magnified image

DSC diagram for P(3HB‐co‐3MP)s biosynthesized in different pH medium.
Iron filled singlewalled carbon nanotubes – synthesis and characteristic properties
Authors: Borowiak‐Palen E. , Bachmatiuk A. , Rümmeli M. H. , Gemming T. , Pichler T. , Kalenczuk R. J.
Published: October 2006

An efficient and simple wet chemistry methodology to synthesize iron filled singlewalled carbon nanotubes (Fe‐SWCNT) is presented. The route leads to the formation of long continuous iron cables within the tubes. Partial filling is also observed. The morphology, high filling aspect and the chemical profile of the produced sample is studied by high resolution transmission electron microscopy and its X‐ray energy dispersive spectroscopy (EDX) mode. The bulk scale chemical composition is confirmed with a bulk sensitive electron energy‐loss spectrometer (EELS). The resulting material exhibits ferromagnetic properties at room temperature and 3 K. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Determinants of cost efficiencies in the mutual fund industry
Authors: Malhotra D.K. , Martin Rand , Russel Philip
Published: October 2006

We evaluate determinants of cost efficiencies in the U.S. mutual fund industry for 1998–2003. Our empirical results show that cost increases in this industry have been less than proportional to increases in assets. We find that funds without a 12b‐1 plan show larger economies of scale than funds with a 12b‐1 plan; institutional funds show greater economies of scale than do retail funds; and that fund families that are more focused in their investment objectives reap benefits of lower fund management costs than do fund families that are more diversified in their investment objectives.
The NIMH MATRICS Initiative: Development of a Consensus Cognitive Battery
Authors: Kern Robert S. , Green Michael F. , Marder Stephen R.
Published: October 2006

ABSTRACT

A key obstacle to the development of new drugs to treat the cognitive deficits of schizophrenia was the absence of a standard by which to measure their efficacy. Before granting approval for any new drug for this condition, the US Food and Drug Administration wanted a standard cognitive endpoint based on a broad consensus-based method. To address this obstacle, the Measurement and Treatment Research to Improve Cognition in Schizophrenia (MATRICS) intiative oversaw a process to develop a consensus neurocognitive battery. Its development included a ten-step process that is described in this article.
Dynamical contrasts between pancake and pack ice, investigated with a drifting buoy array
Authors: Doble Martin J. , Wadhams Peter
Published: October 2006

The motion of pancake ice was investigated using an array of specialised drifting buoys, deployed into the advancing ice edge of the Weddell Sea in April 2000. The buoys remained in the ice as the pancakes consolidated into a coherent ice sheet, and the study examined the contrasts in dynamics for equivalent periods before and after consolidation. Drift velocities were largely determined by the meridional component, perpendicular to the ice edge. Prior to consolidation, these showed significantly elevated magnitudes at high frequencies (periods shorter than six hours). Scalar velocities were higher than previously reported values, reducing with time and distance from the ice edge. The same trends were not evident from in situ wind data. Derivation of momentum transfer parameters (wind factor, turning angle) was hampered by a lack of reliable wind directions from the outermost buoys, however. Relative motions between buoys were investigated using differential kinematic parameters. These displayed high amplitude, high frequency oscillations in unconsolidated ice, with RMS invariant values up to two orders of magnitude higher than normally reported for Weddell Sea pack ice. The values were found to be strongly dependent on sampling interval, increasing further at intervals less than one hour. In situ winds did not display an equivalent variation, suggesting that wind‐forcing was not responsible, and translation under wave action, either internal or surface gravity, was postulated as the forcing.
Analysis of HIV-1 pol sequences using Bayesian Networks: implications for drug resistance
Authors: Deforche K. , Silander T. , Camacho R. , Grossman Z . , Soares M. A. , Van Laethem K. , Kantor R. , Moreau Y. , Vandamme A.-M. ,   on behalf of the non-B Workgroup
Published: October 2006

Human Immunodeficiency Virus-1 (HIV-1) antiviral resistance is a major cause of antiviral therapy failure and compromises future treatment options. As a consequence, resistance testing is the standard of care. Because of the high degree of HIV-1 natural variation and complex interactions, the role of resistance mutations is in many cases insufficiently understood. We applied a probabilistic model, Bayesian networks, to analyze direct influences between protein residues and exposure to treatment in clinical HIV-1 protease sequences from diverse subtypes. We can determine the specific role of many resistance mutations against the protease inhibitor nelfinavir, and determine relationships between resistance mutations and polymorphisms. We can show for example that in addition to the well-known major mutations 90M and 30N for nelfinavir resistance, 88S should not be treated as 88D but instead considered as a major mutation and explain the subtype-dependent prevalence of the 30N resistance pathway.

Contact:  koen.deforche@uz.kuleuven.ac.be

Supplementary information: Supplementary data are available at Bioinformatics online.
Assessment of anti‐inflammatory activity of Poria cocos in sodium lauryl sulphate‐induced irritant contact dermatitis
Authors: Fuchs S. M. , Heinemann C. , Schliemann‐Willers S. , Härtl H. , Fluhr J. W. , Elsner P.
Published: October 2006

Objective: In the present study, we evaluated the anti‐inflammatory activity of Poria cocos (PoCo) on experimentally induced irritant contact dermatitis (ICD) in a repeated sodium lauryl sulphate (SLS) irritation model.

Methods: The anti‐irritative effect of PoCo was evaluated with a visual score and quantified by non‐invasive bioengineering methods, namely chromametry and transepidermal water loss. Three concentrations of PoCo in base cream DAC (amphiphilic emollient; German pharmacopoeia) were tested in a 4‐day repetitive irritation test using SLS.

Results: A statistically significant anti‐inflammatory activity was observed for PoCo by all three methods when applied in parallel to the induction period of ICD. Application of PoCo after induction of ICD once a day for 5 days, starting just at the end of 4 days, was without any effect.

Conclusion: An anti‐inflammatory efficacy of PoCo on the elicitation phase of the ICD induced by repeated SLS test could be observed and quantified by three independent, non‐invasive biophysical assessment parameters. This effect can be explained by its influence on pro‐inflammatory enzymes, namely phospholipase A2.
Costs of patient management of visceral leishmaniasis in Muzaffarpur, Bihar, India
Authors: Meheus Filip , Boelaert Marleen , Baltussen Rob , Sundar Shyam
Published: October 2006

Objectives To identify and quantify the direct and indirect economic cost of treatment for visceral leishmaniasis (VL) with conventional Amphotericin B deoxycholate, currently the first‐line treatment in Muzaffarpur.

Methods Costs of patient management for VL were estimated from a societal and household perspective by means of a questionnaire designed for this study, interviews and financial reports.

Results The total cost of care per episode of VL from the societal perspective was estimated at US$355, equivalent to 58% of annual household income. The largest cost category was medical costs (55%), followed by indirect costs (36%) and non‐medical costs (9%). The cost from the household perspective was equivalent to US$217. The largest cost category was indirect costs (59%), followed by medical costs (27%) and non‐medical costs (15%). Loss of income because of illness and hospitalization and expenses for drugs were the largest cost components.

Conclusions The economic costs related to VL are substantial, both to society and the patient. Public health authorities in Bihar should focus on policies that detect VL in the early stage and implement interventions that minimize the burden to households affected by VL.
Winter mortality of Aceria chondrillae, a biological control agent released to control rush skeletonweed (Chondrilla juncea) in the western United States
Authors: Milan J. D. , Harmon B. L. , Prather T. S. , Schwarzländer M.
Published: October 2006

Abstract:  Classical biological control of weeds is based on the assumptions that: (1) plant species are in part invasive in their introduced range because of the absence of coevolved specialist herbivore arthropods and plant pathogens; and (2) that these specialist herbivores can regulate host‐plant populations. Although the need for quantitative post‐release monitoring studies testing these assumptions has been acknowledged repeatedly, the number of assessments is still remarkably small and usually restricted to systems with notable impact of an agent species. However, studying systems where biological control agents cause no observable target weed reductions may be important to identifying factors that limit the population size or impact of biological control agents. Three biological agents were released for the control of the herbaceous perennial rush skeletonweed, Chondrilla juncea in North America between 1975 and 1977. Although all three species are widely established, weed densities are increasing and there is little quantitative information on factors limiting biological control efficacy. We examined the winter biology and survivorship of the rush skeletonweed gall mite Aceria chondrillae at two rush skeletonweed field sites in south‐western Idaho over 2 years. Gall mite winter mortality was high (>90%) in both years and for both sites. Gall mites were more abundant on plants that produced rosettes in fall and rush skeletonweed plants growing on southern aspect were 3.4 times more likely to produce rosettes than those growing on northern aspects. Our data suggest that A. chondrillae population densities are limited by its high winter mortality. The gall mites may require fall rosettes to successfully survive the winter, which are commonly absent on north‐facing aspects, impairing the efficacy of A. chondrillae to control rush skeletonweed in the intermountain western United States.
DISTRIBUTION OF N‐ACETYL‐l‐ASPARTIC ACID IN RAT BRAIN
Authors: Marcucci F. , Mussini E. , Valzelli L. , Garattini S.
Published: October 2006

The distribution of N‐acetyl‐l‐aspartic acid in the rat brain has been studied by means of a new gas‐chromatographic method. The results obtained concern twelve different brain areas.
THE ISOLATION OF HOMOANSERINE FROM BOVINE BRAIN*†
Authors: Nakajima T. , Wolfgram F. , Clark W. G.
Published: October 2006

Homocarnosine, homoanserine, 3‐methylhistidine, and 1‐methylhistidine have been isolated from bovine brain. The first three compounds were crystallized and compared with the synthetic compounds. The synthesis of homoanserine nitrate is described.
[14C]ACETYLCHOLINE SYNTHESIS BY CORTEX SLICES OF RAT BRAIN12
Authors: Browning E. T. , Schulman M. P.
Published: October 2006

Abstract—

A procedure has been developed to measure ACh synthesis from [14C]‐precursors. As little as 10−9 moles of ACh were detected as the result of de nova synthesis. Following incubation of cortex slices of rat brain with eserine and a tagged metabolite, ACh carrier was added to the incubation medium and to an extract from the slices. ACh was purified by chromatography on Amberlite CG‐50, precipitation and recrystallization of ACh chloroaurate.

[U−14C]glucose and [2−14C]pyruvate formed similar amounts of [14C]ACh. Hydrolysis of ACh with subsequent chromatography of the resultant acetic acid demonstrated that all of the label was located in the acetyl moiety. [14C]acetate did not serve as a precursor of the acetyl group of ACh. Equivalent incorporation of carbons 1 and 6 of glucose into ACh indicated that glucose metabolism to ACh occurred via the Embden‐Meyerhof pathway.

The amount of ACh detected by bioassay after incubation of cortex slices with [U−14C]glucose was approximately the same as that calculated as labelled ACh; this demonstrates that all of the acetyl groups of ACh formed during incubation were derived from glucose.

[14C]choline, either methyl or chain labelled, formed [14C]ACh while labelled ethanolamine, serine and methionine did not. Synthesis from labelled choline did not occur in the absence of glucose.

When both [U−14C]glucose and [14C]choline were incubated with brain slices, the acetyl and choline moieties of ACh were equally labelled; this demonstrates that the entire molecule was formed from added precursors. Slices supported a high rate of ACh synthesis without addition of choline. The addition of 10−4m‐hemicholinium‐3 inhibited ACh formation by more than 90 per cent from either [U‐14C]glucose or [Me‐14C]choline.

Study of the time course of ACh synthesis from glucose demonstrated a rapid formation of [14C]ACh within the slices which reached a maximum during the first hour of incubation. [14C]ACh in the incubation medium accumulated at a linear rate for 3 hr. Replacement of a portion of the sodium chloride of the incubation medium by potassium chloride to a final concentration of 31 mm‐KCI markedly increased the formation of [14C]ACh found in the incubation medium. Decreased amounts of [14C]ACh were extracted from the slices by homogenization or by subsequent heating at pH 4 in the high potassium ion medium.
ACID PHOSPHATASE LOCALIZATION IN INDIVIDUAL NEURONS BY A QUANTITATIVE HISTOCHEMICAL METHOD*
Authors: Hirsch Hilde E.
Published: October 2006

—By an adaptation of the fluorometric method of Campbell and Moss (1961), the activity of α‐naphthyl acid phosphatase was measured in individual neurons of monkey and human spinal cord and found to be many times higher in nerve cell bodies than in the surrounding neuropil. It was also measured in cerebellar cortex and found most concentrated in the granular (neuronal) layer. As this distribution is distinctive and paralleled by two other acid hydrolases, β‐galactosidase and β‐glucuronidase, it is considered to offer additional support for the lysosomal concept in nervous tissue and to indicate that nerve cell perikarya are much richer in lysosomes than are axons, dendrites or glial cells.
CHARACTERIZATION OF SULPHATIDE‐CONTAINING LIPOPROTEINS IN RAT BRAIN1
Authors: Herschkowitz N. , McKhann G. M. , Saxena S. , Shooter E. M.
Published: October 2006

—(1) Water‐soluble [35S]sulphatide is found in the 105,000 g supernatant (SN) of rat brain after intraperitoneal injection of Na235SO4. This labelled sulphatide has a density between those of free lipid and free protein.

(2) Fractionation of SN by preparative acrylamide gel electrophoresis indicates that the [35S]sulphatide is not distributed among all SN proteins, but is associated with certain specific proteins. One of the isolated [35S]sulphatide‐containing proteins appears homogeneous by analytical acrylamide gel electrophoresis at several pH values.

(3) Comparison of the turnover of [35S]sulphatide in microsomes, SN, and myelin indicates that these three subcellular fractions behave as distinct metabolic pools, which meet the requirements for a precursor‐product relationship between microsomes and SN and between SN and myelin.

(4) These results suggest that sulphatide, synthesized in the microsomes, is transported to the myelin membrane as water‐soluble sulphatide containing Iipoproteins in SN.
PROTEIN SYNTHESIS IN THE ISOLATED MAUTHNER NERVE FIBRE OF GOLDFISH
Authors: Edström A. , Sjöstrand J.
Published: October 2006

Abstract— Mauthner nerve fibres isolated from the spinal cord of goldfish were incubated, in the presence of radioactive amino acids for varying periods of time. It was found that the Mauthner fibre synthesizes proteins in the absence of cell nuclei. Amino acid incorporation showed sensitivity to puromycin and to acetoxycycloheximide but resistance to chloramphenicol. Only slight inhibition was caused by actinomycin‐D. The contribution of the denuded axon to the total protein synthesis was about 30 per cent per unit length Mauthner fibre. The remaining activity was due to the myelin sheath compartment. Fractionation experiments showed that the incorporation in the sheath was due to components other than the myelin lamellae. The subcellular distribution of newly synthesized proteins in the isolated and incubated Mauthner fibre was compared to that found in the incubated spinal cord. The results strongly suggested the existence in the Mauthner fibre of a primary microsomal, rather than a mitochondrial, protein synthesizing system.
A RADIOISOTOPIC METHOD FOR MEASURING THE FORMATION OF ADENOSINE 3′,5′‐CYCLIC MONOPHOSPHATE IN INCUBATED SLICES OF BRAIN
Authors: Shimizu H. , Daly J. W. , Creveling C. R.
Published: October 2006

Abstract— A simple and sensitive method for measuring the effect of neurohormones and other chemical agents on the formation of adenosine 3′,5′‐cyclic monophosphate (cyclic 3′,5′‐AMP) in incubated slices of brain was developed. The principle of the method depends on pulse‐labelling of adenosine‐5′‐triphosphate in slices of brain with [8‐14C]adenine, followed by incubation in a medium containing the test substance, separation by thin‐layer chromatography of the cyclic nucleotide formed in the slices, and radioassay. The purity of the cyclic nucleotide was confirmed by chromatography in a variety of systems and by hydrolysis with a specific, bovine‐heart phosphodiesterase. The method was used to study the effect of histamine, norepinephrine, and adenosine on the accumulation of adenosine 3′,5′‐cyclic monophosphate in incubated slices of brain.
MONOAMINE OXIDASE ACTIVITY IN THE HYPOTHALAMUS AND VARIOUS OTHER BRAIN AREAS AND IN SOME ENDOCRINE GLANDS OF THE RAT DURING THE ESTRUS CYCLE12
Authors: Kamberi I. A. , Kobayashi Yutaka
Published: October 2006

—The activity of monoamine oxidase (MAO, EC 1.4.3.4) was measured in the entire hypothalamus and different hypothalamic regions, in the amygdala, frontal and lateral cerebral cortex, in the pituitary, adrenals and genital organs of male rats and of female rats during the estrus cycle. Activity of MAO changed cyclically in the hypothalamus, amygdala, adrenals and ovaries. The highest levels in the hypothalamus occurred at 10 a.m. on the day of proestrus and during estrus. The lowest levels occurred at 6 p.m. on the day of proestrus, of metestrus and during diestrus. Cyclical variations similar to those found in the whole hypothalamus were also observed in anterior, posterior and lateral portions and the median eminence of the hypothalamus. Activity in the median eminence was greater than that of the whole hypothalamus or its various other portions. The amygdala exhibited less marked cyclical activity which followed the pattern of the hypothalamus by increasing at 10 a.m. and peaking at 3 p.m. on the day of proestrus. At the‘post‐critical’period of proestrus, when the activity of MAO in the hypothalamus and amygdala decreased, the activity of MAO in the ovaries and adrenals rose. During the estrus cycle much lower levels of activity of MAO were demonstrated in other regions of the brain (frontal and lateral cerebral cortex), in the pituitary and in the uterus, none of which showed cyclical changes. The changes in activity of MAO in cerebral tissues, endocrine glands and genital organs have been discussed in relation to the probable participation of monoamines in the mechanism(s) of secretion of gonadotrophins by the hypothalamus.
BIOSYNTHESIS OF LACTOSYLCERAMIDE BY RAT BRAIN PREPARATIONS AND COMPARISON WITH THE FORMATION OF GANGLIOSIDE GM1 AND PSYCHOSINE DURING DEVELOPMENT
Authors: Hildebrand J. , Stoffyn P. , Hauser G.
Published: October 2006

—This report deals with some properties of the enzyme from rat brain, which catalyses in vitro the formation of lactosylceramide, a probable precursor of the gangliosides, from UDP‐galactose and glucosylceramide. The enzyme is present in microsomes, mitochondria and synaptosomes, the latter having the highest specific activity, and appears to be firmly bound to the membranes of these particles. The enzymic activity is optimal at pH 6·8 and requires the presence of Mn2+.

Lactosylceramide, the product of the reaction, was tentatively identified by its elution pattern from a Florisil column, its resistance to mild alkaline hydrolysis, thin‐layer co‐chromatography with authentic standards in six solvent systems, and location of the radioactivity in the galactose portion of the product obtained after incubation of labelled UDP‐galactose with unlabelled glucosylceramide and in the glucose portion after incubation of glucose‐labelled glucosylceramide with unlabelled UDP‐galactose.

The activity of this enzyme, per unit of brain weight, was found to be highest at birth and to decrease gradually thereafter. A similar age distribution was observed for another galactosyltransferase, the one which catalyses the formation of ganglioside GM1 from Tay‐Sachs’ganglioside. In contrast, the activity of a third galactosyltransferase, which catalyses the formation of psychosine, and thus possibly is related to the increase of cerebrosides during myelination, is negligible during the first week and maximal about 20 days after birth.
OCCURRENCE AND PROPERTIES OF MONOAMINE OXIDASE IN ADRENERGIC NEURONS
Authors: Jarrott B.
Published: October 2006

—Monoamine oxidase activity of peripheral organs of various species has been examined after surgical, chemical and immunological sympathectomy to assess the proportion of enzyme activity in adrenergic neurons and in extraneuronal cells. Significant falls in monoamine oxidase activity of vas deferens, submaxillary gland, iris and spleen were seen after sympathetic denervation although not in heart, small intestine and kidney. It was suggested that a correlation exists between the extent of the fall in monoamine oxidase activity after sympathectomy and the density of sympathetic innervation of the control organ. Studies of monoamine oxidase activity in vas deferens after inhibition with clorgyline suggested multiple forms of monoamine oxidase. Differences in inhibitor sensitivity, substrate specificity and thermal inactivation of monoamine oxidase in normal and denervated vas deferens were found and it was suggested that differences exist in the properties of the neuronal and extraneuronal monoamine oxidase.
THE EFFECT OF ELECTROCONVULSIVE SHOCK ON PROTEIN SYNTHESIS IN MOUSE BRAIN
Authors: Dunn A. , Giuditta A. , Pagliuca Nicola
Published: October 2006

The effect of a single electroconvulsive shock on protein synthesis in mouse brain cortex was studied by observing the incorporation into protein of intraperitoneally injected [3H]‐ or [14C]leucine. When the precursor was injected immediately after the electroshock there was a 50 per cent inhibition of the incorporation which was not seen with injections at times later than 10 min. To investigate a possible specificity, the cerebral cortices of experimental and sham control animals which had been injected with different isotopes were homogenized together and fractionated by differential centrifugation. Cell fractions were then separately extracted with phosphate buffer and with Triton X‐100. The ratio of 3H to 14C in each fraction was compared with that of the total homogenate to reveal any specific effects due to the electroconvulsive shock. The treatment produced a slight inhibition of the incorporation of the isotope into the heavier particulate fractions (i.e. nuclei, mitochondria, synaptosomes) relative to that in the microsome and cell sap fractions. A possible explanation of these results is given with a discussion of the limitations of the technique.
COMPARATIVE STUDIES ON THE MYELIN PROTEINS OF BOVINE PERIPHERAL NERVE AND SPINAL CORD
Authors: Uyemura K. , Tobari C. , Hirano S. , Tsukada Y.
Published: October 2006

Abstract— (1) Two myelin fractions of bovine peripheral nerve and spinal cord have been studied comparatively. Cholesterol as well as cerebroside content per mg of protein in the peripheral nerve myelin was less than that in the spinal cord myelin, while no significant difference in the total phospholipid content was noted.

(2) The basic proteins in myelin fractions were quantitatively estimated by disc gel electrophoresis. Around one‐fourth of the total myelin protein in the bovine peripheral nerve was a basic protein with a mobility of 1.07 relative to lysozyme by Reisfeld's disc gel electrophoresis.

(3) The myelin proteins in the peripheral nerve were less completely solubilized than those of the spinal cord by treatment with deoxycholate as well as by Triton‐salt solution. The protein fractions obtained from the peripheral nerve myelin by techniques similar to that for obtaining the proteolipids from the spinal cord myelin, contained different types of protein.

(4) 2′,3′‐Cyclic nucleotide 3′‐phosphohydrolase activity in the peripheral nerve myelin was only one tenth of that in the spinal cord myelin. The Triton‐salt insoluble fraction showed remarkable high activity among subfractions of the spinal cord myelin.

(5) By immunological studies, it may be concluded that an antigenic substance for experimental allergic neuritis was localized in the peripheral nerve myelin, but not in its basic protein.
ON THE PHOSPHOLIPASE A2 ACTIVITY OF HUMAN CEREBRAL CORTEX
Authors: Cooper Mary F. , Webster G. R.
Published: October 2006

Abstract— Preparations of phospholipase Az have been obtained from human cerebral cortex. The enzyme was extracted from acetone‐dried tissue and purified by heat‐treatment and gel filtration on Sephadex.

Although heating at 65°C or 70°C destroys most of the phospholipase A1 activity that is present in crude extracts, a small proportion remains associated with the A2 activity during these procedures. The heat‐treated extracts hydrolyse lecithin in preference to phosphatidyl‐ethanolamine but have no action on lysolecithin or neutral lipids. The results suggest that A2 activity and the heat‐stable component of A1 may both be due to a single phospholipase A that can hydrolyse diacylglycerophosphatides at either the 2‐or the 1‐position, to form a mixture of isomeric lysoderivatives.

A molecular weight of 55,000 was calculated for the enzyme.
TAURINE DISTRIBUTION IN CAT BRAIN
Authors: Guidotti A. , Badiani G. , Pepeu G.
Published: October 2006

Abstract— The distribution of taurine was investigated in 16 areas of the brain, in cats transected either at collicular or at midpontine level. A comparison was also made between the content in the same areas of the cerebral cortex of the two groups of cats showing respectively either a synchronized or an activated electrocorticogram. Taurine was determined in picric acid extracts by means of column chromatography followed by thin layer chromatography of the eluates. The levels of taurine were fairly uniform in all areas investigated with the exception of the lateral geniculate bodies, the pituitary gland and the pineal gland where the levels were higher than in all other regions. The taurine content of the cortex of cats showing a synchronized EEG pattern was higher than in the cortex of cats showing an activated pattern. The results are discussed in the light of the limited information available on the possible role of taurine in the CNS.
LEUCINE TRANSPORT FROM THE VENTRICLES AND THE CRANIAL SUBARACHNOID SPACE IN THE CAT1
Authors: Lorenzo A. V. , Snodgrass S. R.
Published: October 2006

Abstract— The clearance of [14C]leucine from the ventricular and cranial subarachnoid space was studied in cats subjected to ventriculo‐cisternal and ventriculo‐craniosubarachnoidal perfusions. Clearance from both the ventricles and the subarachnoid space was mediated by transport mechanisms with nonsaturable and saturable components. Net clearance from the subarachnoid space was considerably greater than from the ventricles. Analysis of the transport kinetics revealed the affinity constants (Kt) to be comparable for both compartments but transport sites appeared to be more numerous in the subarachnoid space (greater Vmax).

Proportionally, the amount of [14C]leucine retained by brain declined as the concentration of leucine in the perfusate was increased. Since at high concentrations the CSF transport systems and presumably cellular uptake were inhibited (self‐saturated) it was assumed that the lower brain levels of [14C]leucine reflected a proportionately greater loss of [14C]‐leucine from the brain interstitial space to blood.
EFFECTS OF CORTICOSTEROIDS ON THE BIOCHEMICAL MATURATION OF RAT BRAIN: POSTNATAL CELL FORMATION
Authors: Cotterrell Mary , Balaazs R. , Johnson A. L.
Published: October 2006

(1) Treatment with cortisol acetate (0.2 mg daily during the first 4 days after birth) reduced the rate of growth in the rat: at 35 days of age the body weight was reduced by 50 per cent and the brain weight, depending on the region, by up to 30 per cent.

(2) In the brain the normal increase in cell number was severely inhibited during the period of cortisol treatment; this resulted in a final deficit in cell number of about 20 per cent in the cerebrum and 30 per cent in the cerebellum.

(3) To determine whether cortisol affected primarily cell formation or cell destruction the labelling of brain DNA was studied 1 h after a subcutaneous injection of 20 Ci/100 g [2‐14C]thymidine. In the controls the amount of labelled DNA increased by a factor of two in the cerebrum and seven in the cerebellum during the period 2‐13 days, and it decreased to 40 and 27 per cent of the peak values in the cerebrum and cerebellum respectively in the following 7 days. The results indicated that mitotic activity is higher in the cerebellum than in the cerebrum in the 2nd week of life. It would appear that in the cerebrum appreciable cell death accompanies new cell formation, especially during the period 13‐35 days of age.

(4) Cortisol treatment affected cell division rather than cell destruction in the brain since it strongly inhibited the incorporation of [2‐14C]thymidine into DNA. The inhibition was severe during the period of treatment but it did not result in a lasting fall in mitotic activity. At the age of 13 days the amount of labelled DNA formed approached the normal level and it was twice that in controls at 20 days, indicating a tendency for compensating cell deficit by an accelerated mitotic activity. Nevertheless, massive cell proliferation ceased at about the same age as in normals; the labelling of DNA decreased markedly between 13 and 20 days after birth, and the DNA content did not increase after the age of 20 days.

(5) In contrast to the marked effect on cell number, cortisol treatment did not influence significantly the maturational changes related to average cell size (DNA concentration) or the chemical composition of cells (RNA/DNA and protein/DNA).
ON THE MECHANISM OF THE NULLIFICATION OF CNS EFFECTS OF l‐DOPA BY PYRIDOXINE IN PARKINSONIAN PATIENTS1
Authors: Pfeiffer R. , Ebadi M.
Published: October 2006

Administration of either Levodopa (l‐DOPA) or pyridoxine increased the concentration of dopamine in the basal ganglia of rats. However, administration of pyridoxine to rats pretreated with l‐DOPA for several days resulted in a reversal of the l‐DOPA‐induced elevation of dopamine. Pretreatment of rats with Ro 4‐4602 (an inhibitor of peripheral aromatic amino acid decarboxylases) enhanced the l‐DOPA‐induced rise in the CNS level of dopamine. This effect was also reduced substantially after the administration of pyridoxine. We interpret these results to indicate that the antagonistic effect of pyridoxine on the beneficial effects of l‐DOPA in the CNS is centrally mediated as a result of decreased formation of dopamine.
THE REGIONAL DISTRIBUTION OF THE POLYAMINES SPERMIDINE AND SPERMINE IN BRAIN
Authors: Shaw G. G. , Pateman A. J.
Published: October 2006

Abstract— The distribution in brain of the polyamines spermidine and spermine is described in the rat, dog, sheep, rabbit and in man. The distribution pattern was about the same in all the species, spermidine concentration being highest in areas rich in white matter. The concentration of spermine was lower than that of spermidine and showed less variation from area to area. Rat brain polyamine content was the same in rats killed by decapitation as in those killed by rapid freezing in liquid nitrogen and was also unchanged up to 48 h after the death of the animal.
The occurrence of N‐acetylaspartate amidohydrolase (Aminoacylase II) in the developing rat1
Authors: D'Adamo A. F. , Smith J. Crispin , Woiler C.
Published: October 2006

Of The amino acids and derivatives, N‐acetyl‐L‐aspartic acid is present in a uniquely high level (5–6 μmol/g) in the brain of mammals after myelination has occurred. Much lower levels (0·06–0·17 μmol/g) are found prior to this stage of brain development (Tallan, 1957). In non‐nervous tissues, on the other hand, only trace amounts of this acetyl amino acid are present (Tallan, Moore and Stein, 1956). N‐acetyl aspartic acid serves as an excellent source of acetyl groups for lipogenesis in the developing rat brain (D'Adamo and Yatsu, 1966; Dadamo, Gidez and Yatsu, 1968). Non‐nervous tissues such as kidney and mammary gland also rapidly metabolize the acetyl amino acid, the former tissue converting the acetyl group primarily to CO2 and the latter to fatty acids (Benuck and D'Adamo, 1968). An enzyme with a high specificity for N‐acetyl‐L‐aspartic acid initially termed aminoacylase II, was originally isolated from hog kidney by Birnbaumet al. (1952). Since the physiological role of the substrate is not known, it was of interest to study the occurrence of this enzyme, N‐acetyl‐L‐aspartate amidohydrolase (EC 3.5.1.15), in developing tissues of the rat.
EVIDENCE FOR DEGENERATION OF SYMPATHETIC NERVE TERMINALS CAUSED BY THE ORTHO‐ AND PARA‐QUINONES OF 6‐HYDROXYDOPAMINE
Authors: Heikkila R. E. , Mytilineou C. , Cócté L. , Cohen G.
Published: October 2006

6‐Hydroxydopamine and its corresponding ortho‐ and para‐quinones were injected intraperitoneally into male Swiss‐Webster mice. Measurements made 72 h after injection showed that all three compounds caused a decrease in the uptake of [3H]norepinephrine into slices of mouse heart tissue in vitro, a decrease in the endogenous content of heart norepine‐phrine, and a disappearance of the adrenergic nerve plexus of the mouse iris as viewed by fluorescence histochemistry. These data suggest that both the ortho‐ and para‐quinones of 6‐hydroxydopamine are capable of producing a chemical sympathectomy similar to that caused by 6‐hydroxydopamine.
Estrone sulphate in rat brain: uptake from blood and metabolism in vivo12
Authors: Kishimoto Y.
Published: October 2006

It Has been well established that the estrogens, estrone and estradiol, enter the brain from the circulatory system. These compounds are concentrated and retained in the hypothalamus and preoptic regions, particularly in the nuclei of the cells in these regions (McEwen, ZIGMOKD, AZMITIA and Weiss, 1970; Zigmond and Mcewen, 1970). In a previous communication from this laboratory we indicated that a small portion of blood bound dehydroepiandrosterone sulfate enters the brain intact and then is converted to free dehydroepiandrosterone and to androstenediol sulfate (Kishimoto and Hoshi, 1972). Estrone sulfate is the most abundant estrogen in plasma at a concentration of 0.349 pg/ml of plasma, a level which is as much as 10‐fold higher than that of free estrone and estradiol in both male and female plasma (Loriaux, Ruder and Lipsett, 1971). Therefore, we deemed it important to establish whether estrone sulfate also enters the brain and if it acts as the source of other brain estrogens. In this communication, we wish to report the results obtained by intracardiac and intracerebral injection of [3H] estrone [35S] sulfate into the developing rat.
THE EFFECT OF l‐3,4‐DIHYDROXYPHENYLALANINE ADMINISTRATION ON GLUCOSE METABOLISM IN BRAIN1
Authors: Tyce Gertrude M. , Owen C. A.
Published: October 2006

The effect of the administration of l‐3,4‐dihydroxyphenylalanine (l‐DOPA) on the metabolism of glucose in brain was studied by administering [U‐14C]glucose to three groups of rats: (1) those injected previously with l‐DOPA, 100 mg/kg; (2) those fed 1 % (w/w) l‐DOPA in their diet for several months and also injected 15 min before the administration of glucose with l‐DOPA, 100 mg/kg; and (3) appropriate controls. Chronic treatment with l‐DOPA caused a decrease in the flux of carbon from glucose in plasma to those amino acids in brain that are in equilibrium with the tricarboxylic acid cycle intermediates but not to lactate and alanine. Similar differences from controls, but of smaller magnitude, were observed in rats given a single injection of l‐DOPA. Concentrations of glucose in plasma and in brain were increased after acute or chronic treatment with l‐DOPA. A single injection of l‐DOPA did not cause changes in the levels of the most abundant amino acids in brain, but after chronic treatment with l‐DOPA modest changes were noted in the brain levels of some ninhydrin‐reacting substances; the contents of taurine and aspartate were lower and those of threonine, serine, glutamine, and glycine were higher.
STUDIES ON RNA SYNTHESIS IN TWO POPULATIONS OF NUCLEI FROM THE MAMMALIAN CEREBRAL CORTEX
Authors: THOMPSON R. J.
Published: October 2006

A method is presented for the rapid separation of cell nuclei from the rabbit cerebral cortex into two populations. The first of these consists largely of nuclei with the morphological characteristics of neuronal nuclei, the second almost entirely of nuclei with the morphological characteristics of glial cell nuclei. From studies based upon sensitivity to the toxin α‐amanitin, the ratio of incorporation of different bases, ionic requirements and differential sensitivity to actinomycin D, it is concluded that under both the classical low and high salt conditions described by other workers, two enzymes are active in RNA synthesis. The presence of a third enzyme of low activity cannot be excluded. No qualitative difference in the number of enzymes involved in RNA synthesis in neuronal and glial cell nuclei has been found, but there are quantitative differences in activity between the two nuclear populations.
SOME ENZYMIC ASPECTS OF THE PRODUCTION OF OXIDIZED OR REDUCED METABOLITES OF CATECHOLAMINES AND 5‐HYDROXYTRYPTAMINE BY BRAIN TISSUES
Authors: Duncan R. J. S. , Sourkes T. L.
Published: October 2006

The Michaelis constants of purified aldehyde dehydrogenase (aldehyde: NAD oxidoreductase, EC 1.2.1.3) and aldehyde reductases (alcohol: NADP oxidoreductase, EC 1.1.1.2) from pig brain have been obtained for a number of biologically important aldehydes. The aldehydes include 3,4‐dihydroxyphenylacetaldehyde, D‐3,4‐dihydroxyphenylglycolaldehyde, and 5‐hydroxyindoleacetaldehyde. The relative activities of the aldehyde‐catabolizing enzymes in the soluble fractions of the cerebral cortex and caudate nucleus of pig brain have also been obtained. The values are used to show that the metabolic fates of the various aldehydes—and hence of the parent amines—may be explained in terms of the simple kinetics of these enzymes. It is also shown that the metabolic fates of the aldehydes may be influenced by their rates of synthesis. As the rate of aldehyde production increases the proportion of aldehyde reduced may be expected to increase at the expense of the proportion of aldehyde oxidized.

It is further concluded from the kinetic constants that selective inhibition of aldehyde dehydrogenase may greatly affect the catabolism of dopamine and 5‐hydroxytryptamine by altering the relevant aldehyde concentrations, while the catabolism of norepinephrine is little affected under these circumstances. Conversely, it is concluded that selective inhibition of the aldehyde reductases should scarcely affect the catabolism of dopamine and 5‐hydroxytryptamine, but that the catabolism of norepinephrine should be markedly affected.

The results also indicate that the concentrations of the various deaminated metabolites of the biogenic amines could be selectively controlled by modulation of the activity of the enzymes of aldehyde catabolism in brain.
ALTERATIONS IN CYCLIC AMP METABOLISM ASSOCIATED WITH PHOTORECEPTOR CELL DEGENERATION IN THE C3H MOUSE1
Authors: Lolley R. N. , Schmidt Susan Y. , Farber Debora B.
Published: October 2006

Previous studies have shown an abnormality in cyclic nucleotide phosphodiesterase activity in the retina of mice (C3H/HeJ) with an inherited degeneration of the photoreceptor layer. Adenyl cyclase activity and cyclic AMP content have been measured in C3H retina and compared with that in normal retina (DBA/1J) during postnatal maturation, to assess the influence of the mutation upon cyclic AMP metabolism. Adenyl cyclase activity increases normally for the first 7 days of age; thereafter, it becomes greater than normal. Cyclic AMP becomes obviously abnormal after 10 days of age. The elevated levels of cyclic AMP persist in the surviving cells of the inner layers of the adult C3H retina. Adenyl cyclase activity and cyclic AMP content are concentrated in the inner layers of the normal retina, while the photoreceptor layer has only a very low level of enzyme activity and cyclic AMP. The data suggest that the synthesis of cyclic AMP in the inner layers of C3H retina is significantly enhanced, during the period of postnatal development in which the photoreceptor cells have begun to degenerate.
CHANGES OF ENZYME PATTERN IN THE SYMPATHETIC NERVOUS SYSTEM OF ADULT MICE AFTER SUBMAXILLARY GLAND REMOVAL; RESPONSE TO EXOGENOUS NERVE GROWTH FACTOR
Authors: Hendry I. A. , Thoenen H.
Published: October 2006

—Removal of the submaxillary glands, the apparent site of NGF synthesis in adult mice, caused a decrease in the activity of all the enzymes involved in the biosynthesis of noradrenaline in the peripheral sympathetic nervous system. Thus, tyrosine hydroxylase (phenylalanine 4‐monooxygenase, EC 1.14.16.1) DOPA decarboxylase (EC 4.1.1.28.) and dopamine β‐hydroxylase (EC 1.14.17.1.) showed reduced activity 10 days after removal of the submaxillary glands in both superior cervical and stellate ganglia. This decrease in enzyme activity persisted up to 100 days after surgery. The fourth enzyme studied, choline acetyl‐transferase (EC 2.3.1.6.) which is exclusively localized within the presynaptic cholinergic terminals of the ganglia was not affected by sialectomy. A dose of 50 μg NGF/animal/day given over 4 days was only able to restore the enzyme activity to control levels in the superior cervical ganglia of sialectomized mice whereas in stellate ganglia the enzyme activities rose above control levels to a similar extent in sialectomized and non‐sialectomized animals.

These results provide biochemical evidence that NGF may play a role not only during the growth and normal development of the peripheral sympathetic nervous system but also in the maintenance of its functional integrity in the adult animal.
THE PRIMARY BIOCHEMICAL LESION LEADING TO THE DELAYED NEUROTOXIC EFFECTS OF SOME ORGANOPHOSPHORUS ESTERS
Authors: Johnson M. K.
Published: October 2006

—In contrast with neurotoxic organophosphates of the type (RO)2P.O.X several phosphinates (R2P.O.X) cause prolonged inhibition of ‘neurotoxic esterase’in vivo but do not cause delayed neurotoxicity even after repeated administration. Prior administration of these phosphinates protected hens against the neurotoxic effects of several organophosphates: this protection lasted until about 70 per cent of the enzyme site again became available for phosphorylation. In this respect phosphinates behave like carbamate and sulphonyl fluoride inhibitors of ‘neurotoxic esterase'. It is proposed that the development of delayed neurotoxicity requires phosphorylation of the esterase followed by hydrolysis of one remaining phosphoryl ester bond to produce a charged monosubstituted phosphoric acid group attached to the protein. Generation of such a group could not occur after inhibition by the protective phosphinates, carbamates or sulphonates. It is proposed that the charged group is responsible for the metabolic disturbance leading to degeneration of long axons.
IN VIVO METHYLATION AND TURNOVER OF RAT BRAIN HISTONES
Authors: Duerre J. A. , Lee Catherine Ting
Published: October 2006

Abstract— The turnover of the different histone components from brain nuclei was studied after the administration of l‐[3H]lysine and l‐[14C‐methyl]methionine to newborn rats. The radioactivities of the different histone subfractions as well as other proteins were determined over a 280‐day period. Biphasic type decay curves (3H and 14C) were obtained for total brain histones and all the subfractions. From 6 to 40 days of age the half life of total brain histones was 19 days. After reaching brain maturity the half life was 132 days. The lysine rich histone (F1) was found to turnover the fastest of all the histones, having half lives of 13 and 112 days, respectively. The decay curve for the slightly lysine rich histones (F2a2, F2b) gave half lives of 25 days up to 40 days of age and 189 days after reaching brain maturity. The arginine rich histones (F2a1, F3) gave a half life of 32 days up to 40 days of age, while no turnover was observed after maturity. The turnover rates of the methyl groups and/or methionyl residues did not vary significantly from the turnover rates of the lysyl residues in the F2 and F3 histones. The lysine‐rich histones did not contain significant amounts of methionyl residues or methyl groups.

Amino acid analysis of the brain histones revealed that about 3·6 per cent of the lysyl residues in the slightly lysine rich histones were methylated, mainly as ε‐N‐dimethyllysine. About 13 per cent of the lysyl residues in the arginine rich histones were methylated, mainly as ε‐N‐monomethyllysine and ε‐N‐dimethyllysine.
ELECTROPHORETIC PROFILES OF AQUEOUS‐SOLUBLE PROTEINS OF HUMAN CEREBRAL CORTEX: POPULATION AND DEVELOPMENTAL CHARACTERISTICS1
Authors: Caplan R. , Cheung Shelly C.‐Y. , Omenn G. S.
Published: October 2006

—Aqueous‐soluble brain proteins from 100 adult humans have been screened by discontinuous polyacrylamide and by continuous‐SDS‐polyacrylamide electrophoresis for evidence of genetically determined variation. In addition 42 adult Macaca nemestrina and 36 inbred strains of mice were screened in the SDS‐continuous system. No variation in position of major bands was found within species, although differences in relative intensity of staining were noted. Fetal human cerebral cortex gave profiles of aqueous‐soluble proteins distinguishable from that of adults. After affinity chromatography on Concanavalin‐A‐agarose, adult samples gave one band on SDS‐polyacrylamide gels, while fetal samples gave the same band plus an additional band, presumably representing glycoproteins.