bluuebunny/crossref_metadata_2025 huggingface dataset:
One‐Step Electrochemical Immunoassay for Carcinoembryonic Antigen in Human via Back‐Filling Immobilization of Gold Nanoparticles on DNA‐Modified Gold Electrodes
Authors: Tang Dian‐Quan , Zhang Da‐Jun , Tang Dian‐Yong , Ai Hua
Published: October 2006

A new amperometric immunobiosensor for carcinoembryonic antigen (CEA) determination in human serum was developed via encapsulation of horseradish peroxidase‐labeled carcinoembryonic antibody (HRP‐anti‐CEA) in a gold nanoparticles/DNA composite architecture. The presences of gold nanoparticles provided a congenial microenvironment for the immobilized biomolecules and decreased the electron transfer impedance, leading to a direct electrochemical behavior of the immobilized HRP. The formation of the antibody–antigen complex by a simple one‐step immunoreaction between the immobilized HRP‐anti‐CEA and CEA in sample solution introduced a barrier of direct electrical communication between the immobilized HRP and the gold electrode surface. Under optimal conditions, the current change obtained from the labeled HRP relative to H2O2 system was proportional to the CEA concentration in two linear ranges from 0.5 to 15 ng/mL and 15 to 300 ng/mL with a detection limit of 0.1 ng/mL (at 3δ). The precision and reproducibility are acceptable with the intraassay CV of 6.3% and 4.7% at 8 and 60 ng/mL CEA, respectively. The storage stability of the proposed immunosensor is acceptable in a pH 7.0 PBS at 4 °C for 9 days. Moreover, the proposed immunosensors were used to analyze CEA in human serum specimens. Analytical results of clinical samples show the developed immunoassay has a promising alternative approach for detecting CEA in the clinical diagnosis.
Cobalt Phthalocyanine Molecular Electrode for the Electrochemical Investigation of the Release of Glutathione upon Copper‐Catalyzed Decomposition of S‐Nitrosoglutathione
Authors: Sehlotho Nthapo , Griveau Sophie , Nyokong Tebello , Bedioui Fethi
Published: October 2006

Decomposition of S‐nitrosoglutathione (GSNO) in phosphate buffer solution at physiological pH 7.4 in the presence of cuprous ion as a catalyst and sodium borohydride as a reducing agent is analyzed by observing the transient apparition of reduced glutathione GSH through its electrooxidation. Transient formation of GSH, upon decomposition of 1 mM GSNO in presence of 0.025 mM Cu(NO3)2 and 1 mM NaBH4 was detected by using an ordinary pyrolytic graphite electrode modified with an adsorbed monolayer of cobalt phthalocyanine at 0 V vs. SCE.
Generation of ultra‐fast laser pulses using nanotube mode‐lockers
Authors: Rozhin A. G. , Scardaci V. , Wang F. , Hennrich F. , White I. H. , Milne W. I. , Ferrari A. C.
Published: October 2006

We report a simple way to fabricate a high optical quality single wall carbon nanotubes (SWNTs) polyvinyl alcohol (PVA) composite. The composites demonstrate strong saturable absorption at ∼1.5 μm, the spectral range for optical communications. These are used as mode‐lockers in a fiber laser. We achieve ∼713 fs pulse generation and up to 8 mW output power. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
1‐Density operators and algebraic version of the Hohenberg–Kohn theorem
Authors: Panin A. I.
Published: October 2006

Interrelation of the Coleman's representabilty theory for 1‐density operators and abstract algebraic form of the Hohenberg–Kohn (HK) theorem is studied in detail. Convenient realization of the HK set of classes of 1‐electron operators and the Coleman's set of ensemble representable 1‐density operators is presented. Dependence of the HK class structure on the boundary properties of the ground‐state 1‐density operator is established and is illustrated on concrete simple examples. An algorithm of restoration of many electron determinant ensembles from a given 1‐density diagonal is described. A complete description of the combinatorial structure of Coleman's polyhedrons is obtained. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007
Simulation of a push belt CVT considering uni‐ and bilateral constraints
Authors: Geier T. , Foerg M. , Zander R. , Ulbrich H. , Pfeiffer F. , Brandsma A. , van der Velde A.
Published: October 2006

In this paper, a two dimensional hybrid model of a continuously variable transmission with push belt is provided. The system is characterized by a large number of contacts with impacts and friction. These interactions are modeled by uni‐ and bilateral constraints also considering friction. The established equations of motion are integrated numerically by a time‐stepping algorithm. The simulation model allows for the computation of the dynamics of the push belt and all contact forces.
Human breast cancer cell lines and tissues express tartrate‐resistant acid phosphatase (TRAP)
Authors: Adams Lisa M. , Warburton Michael J. , Hayman Alison R.
Published: October 2006

Tartrate‐resistant acid phosphatase (TRAP) is expressed by osteoclasts, macrophages and dendritic cells. TRAP has been identified in a wide variety of tissues, however, its biological function is not fully understood. Serum TRAP is a marker of diseases involving excessive bone resorption including metastatic bone disease in breast cancer patients and can be used to monitor responses to treatment. Our aim in this study was to determine whether TRAP is expressed by human breast tumours. Four breast cancer cell lines were assayed for TRAP activity. MDA‐MB‐435, the most tumourigenic line, had an activity twofold higher than the other cell lines. Immunohistochemistry using a TRAP specific antibody confirmed that both cell lines and human breast tumours express TRAP. Expression was absent in benign tissues and abundant in more aggressive tumours. This work suggests that tumour derived TRAP contributes to the raised enzyme activity found in the serum of breast cancer patients.
Observation of night OH in the mesosphere
Authors: Pickett H. M. , Read W. G. , Lee K. K. , Yung Y. L.
Published: October 2006

Satellite measurements from the Aura MLS instrument show a layer of OH near 82 km in the night. This layer confirms earlier measurements by ground‐based LIDAR. The MLS and LIDAR observations measure OH in the lowest vibrational state and are distinct, but related chemically, from vibrationally‐excited emission from the OH Meinel bands in the near infrared. The Caltech 1‐D model has been extended to include vibrational dependence of OH reactions and shows good agreement with MLS OH data and with observations of the Meinel bands. The model shows a chemical lifetime of HOx that increases from less than a day at 80 km to over a month at 87 km. Above this altitude transport processes become an important part of HOx chemistry. The model predicts that ground state OH represents 99% of the total OH up to 84 km.
Role of eastward propagating convection systems in the diurnal cycle and seasonal mean of summertime rainfall over the U.S. Great Plains
Authors: Jiang Xianan , Lau Ngar‐Cheung , Klein Stephen A.
Published: October 2006

By diagnosing the 3‐hourly North American Regional Reanalysis rainfall data set for the 1979–2003 period, it is illustrated that the eastward propagation of convection systems from the Rockies to the Great Plains plays an essential role for the warm season climate over the central U.S. This eastward propagating mode could be the deciding factor for the observed nocturnal rainfall peak over the Great Plains. The results also suggest that nearly half of the total summer mean rainfall over this region is associated with these propagating convection systems. For instance, the extreme wet condition of the 1993 summer may be attributed to the frequent occurrence of propagating convection events and enhanced diurnal rainfall amplitude over the Great Plains. Thus, proper representation of this important propagating component in GCMs is essential for simulating the diurnal and seasonal mean characteristics of summertime rainfall over the central US.
Striated auroral kilometric radiation emission: A remote tracer of ion solitary structures
Authors: Mutel R. L. , Menietti J. D. , Christopher I. W. , Gurnett D. A. , Cook J. M.
Published: October 2006

We describe the statistical properties of narrowband drifting auroral kilometric radiation (“striated” AKR) based on observations from the Cluster wideband receiver during 2002–2005. We show that the observed characteristics, including frequency drift rate and direction, narrow bandwidth, observed intensity, and beaming angular sizes are all consistent with triggering by upward traveling ion solitary structures (“ion holes”). We calculate the expected perturbation of a horseshoe electron distribution function by an ion hole by integrating the resonance condition for a cyclotron maser instability (CMI) using the perturbed velocity distribution. We find that the CMI growth rate can be strongly enhanced as the horseshoe velocity distribution contracts inside the passing ion hole, resulting in a power gain increase greater than 100 dB. The gain curve is sharply peaked just above the R‐mode cutoff frequency, with an effective bandwidth ≤50 Hz, consistent with the observed bandwidth of striated AKR emission. Ion holes are observed in situ in the acceleration region moving upward with spatial scales and speeds consistent with the observed bandwidth and slopes of SAKR bursts. Hence we suggest that SAKR bursts are a remote sensor of ion holes and can be used to determine the frequency of occurrence, locations in the acceleration region, and lifetimes of these structures.
Change in phase separation and electronic structure of nitrided Hf-silicate films as a function of composition and post-nitridation anneal
Authors: Cho M.-H. , Chung K. B. , Ko D.-H.
Published: October 2006

The thermal stability and electronic structure of nitrided xHfO2∙(100−x)SiO2 (HfSiO) (x=25%, 50%, and 75%), prepared using an NH3 annealing treatment, were investigated. The quantity of N incorporated into the Hf-silicate film was dependent on the mole fraction of SiO2 in the film: i.e., a silicate film containing a high mole fraction of SiO2 contained a higher quantity of N, resulting in the suppression of phase separation. In particular, the incorporated N easily diffuses out through a silicate film that contains a small quantity of SiO2 during the post-nitridation anneal, while in a film with a high quantity of SiO2, it is relatively stable. The phase separation effect in the nitrided film with a low SiO2 mole fraction was significantly influenced by the stability of N in the film and interface.
Compression of stacked niobium bilayers: Void-induced strain localization at interfaces
Authors: Liu Y. , Brunner D. , Ruehle M.
Published: October 2006

An optical full-field strain mapping technique has been used to provide direct evidence for the existence of a highly localized strain at the interface of stacked Nb∕Nb bilayers during the compression tests loaded normal to the interface. No such strain localization is found in the bulk Nb away from the interface. The strain localization at the interfaces is due to a high void fraction resulting from the rough surfaces of Nb in contact, which prevents the extension of deformation bands in bulk Nb crossing the interface, while no distinguished feature from the stress-strain curve is detected.
Artificial evolution extends the spectrum of viruses that are targeted by a disease-resistance gene from potato
Authors: Farnham Garry , Baulcombe David C.
Published: October 2006

A major class of disease-resistance (R) genes in plants encode nucleotide-binding site/leucine-rich repeat (LRR) proteins. The LRR domains mediate recognition of pathogen-derived elicitors. Here we describe a random
in vitro
mutation analysis illustrating how mutations in an R protein (Rx) LRR domain generate disease-resistance specificity. The original Rx protein confers resistance only against a subset of potato virus X (PVX) strains, whereas selected mutants were effective against an additional strain of PVX and against the distantly related poplar mosaic virus. These effects of LRR mutations indicate that
in vitro
evolution of R genes could be exploited for enhancement of disease resistance in crop plants. Our results also illustrate how short-term evolution of disease resistance in wild populations might be toward broader spectrum resistance against multiple strains of the pathogen. The breadth of the disease-resistance phenotype from a natural R gene may be influenced by the tradeoff between the costs and benefits of broad-spectrum disease resistance.
Mechanobiology and force transduction in scars developed in darker skin types
Authors: Quatresooz Pascale , Hermanns Jean Francois , Paquet Philippe , Piérard Gérald E.
Published: October 2006

Background: Scarring is a complex process involving many cell types, cytokines and biological pathways including mechanobiology. Some subtle mechanical properties of skin can be assessed by measuring the speed of ultrasound shear wave propagation. The orientation of abnormal skin tension forces can be visualized, particularly in darker skin types, using dermoscopy showing distinct patterns of rete ridges' conformation.

Aim: To assess some mechanobiological features of scars in darker skin types.

Patients and methods: Large atrophic and hypertrophic surgical scars were examined on the trunk of 35 darker skin subjects. The surrounding skin was used as a comparator. Dermoscopic aspects were recorded. Resonance running time measurements (RRTM) were performed using a shear wave propagation device (Reviscometer®). They were performed in four specific directions at given angles with regard to the long axis of the scar. The minimum, maximum and mean RRTM values were recorded at each site.

Results: Dermoscopy revealed patterns of melanin deposits in scars distinct from the normal honeycomb network seen in the surrounding skin. Hypertrophic scars showed a patchy pattern of large macular melanoderma dispersed in a lighter background. In these cases, low RRTM values were obtained with little variations according to the orientation of the measurements. By contrast, atrophic scars showed a streaky laddering melanotic pattern under dermoscopy. Higher RRTM values were often obtained, particularly in the transversal direction of the scars. Mechanical anisotropy was greater in the atrophic scars compared with the normal skin.

Discussion: Darker skin types represent a model for visualizing the main orientation of the epidermal rete ridges. A correlation was found between the pattern of melanized rete ridges of scars and the main orientation of the intrinsic forces in the skin.
Natural priming as an important metabolic event in the life history of Wigandia urens (Hydrophyllaceae) seeds
Authors: Gamboa‐deBuen Alicia , Cruz‐Ortega Rocio , Martínez‐Barajas Eleazar , Sánchez‐Coronado María Esther , Orozco‐Segovia Alma
Published: October 2006

Natural priming promotes fast and synchronic seed germination and enhances the establishment of seedlings from Wigandia urens seeds. In this study, seeds of this species were buried in the field in three different sites, and each site was divided into three different microsites (natural priming). They were then exhumed and air‐dried at the beginning of the rainy season. The control and exhumed W. urens seeds were tested for differences in germination, and in the protein patterns derived from heat‐stable and phospho‐protein enriched fractions, sucrose concentrations, amylase isoenzyme patterns, as well as catalase activity and H2O2 levels. All the exhumed seeds germinated faster and more synchronically than the control seeds. Nevertheless, the germinative pattern showed a microsite effect related to the microenvironmental conditions. Most exhumed samples kept the germinative advantages acquired from the soil during natural priming for 2 years but seeds from the most heterogeneous site (a forest gap) did not. Natural priming also promoted mobilization of 7‐S globulin‐like proteins, solubilization of the 11‐S globulin‐like proteins as well as sucrose consumption before radicle protrusion. Although there were no changes in starch concentration during the germination of either the control or buried seeds, a different isoenzyme amylase pattern was observed. Catalase activity decreased and hydrogen peroxide levels were lower in exhumed seeds during germination. The changes in the protein and sucrose patterns were related to advances in the germinative process acquired during burial. Metabolic advantages were maintained systematically in all seed samples along the 2 years. The ecological significance of natural priming is discussed.
Development of the herbivore Pieris rapae and its endoparasitoid Cotesia rubecula on crucifers of field edges
Authors: Harvey J. A. , Wagenaar R.
Published: October 2006

Abstract:  Several studies have reported that flowering herbs, which grow naturally or are sown adjacent to agricultural fields, may be an important source of nutrients for natural enemies. Many parasitoids readily feed on plant exudates such as floral nectar, which contain different types of sugars that enable the insects to optimize their longevity, mobility and reproductive success. However, leaf tissues of plants grown in the margins of agricultural fields may also provide food for immature stages of insect herbivores, such as caterpillars, that are in turn attacked by parasitoids. Herbivores and their parasitoids may later disperse into the crop, so the nutritional quality of surrounding plants, as this affects herbivore and parasitoid fitness, may also influence the success of biological control programmes, especially later in the season. Here, we compare the suitability of three species of cruciferous plants (Brassicaceae) on the development of Pieris rapae L. (Lep., Pieridae) and its solitary endoparasitoid, Cotesia rubecula Marshall (Hym., Bracondiae). Insects were reared on a feral population of cabbage, Brassica oleracea, on radish Raphanus sativus, which is widely sown in agricultural margins, and on hedge mustard, Sisymbrium officinale, a wild crucifer which often grows in medium to large stands along road verges and field edges. Development time in both the herbivore and parasitoid were extended on R. sativus, compared with the other two species, whereas C. rubecula completed its development most rapidly on B. oleracea. Moreover, adult butterflies and parasitoids were significantly smaller when reared on R. sativus plants. Our results reveal that differences in the quality of plants growing adjacent to agricultural fields can affect the development of key herbivores and their parasitoids. This should be borne in mind when establishing criteria for the selection of floral biodiversity.
A RADIOAUTOGRAPHIC STUDY OF THE SYNTHESIS OF PHOSPHORUS COMPOUNDS IN CENTRAL NERVOUS TISSUES OF THE DOG
Authors: Morita S. , Kobayashi Y. , Ito Y.
Published: October 2006

Gross and microscopic radioautographic observations have been made on the sequential distribution of 32P in the brain and spinal cord of the dog after intracisternal injection as orthophosphate.

There appear to be two stages in the process of 32P incorporation into central nervous tissues. In the first, the phosphate in the CSF penetrates the central nervous tissue by diffusion. In the second, the phosphate is incorporated into various organic compounds in response to metabolic processes.

The chronological changes in intraneuronal 32P localization indicate incorporation into cellular protein, RNA, DNA, and lipid and depend upon the turnover rate of 32P in these fractions.

In the metabolism of phosphate the molecular layer of the cerebellum probably is involved only in rapid changes reflected by the acid‐soluble fraction. The cellular layers in addition are concerned with slower processes such as incorporation into structural compounds.
SOME OBSERVATIONS ON THE ESTIMATION OF TRYPTAMINE IN TISSUES
Authors: Eccleston D. , Ashcroft G. W. , Crawford T. B. B. , Loose R.
Published: October 2006

The method of Hess and Udenfriend (1959) for the estimation of tryptamine in tissues, is demonstrated to allow the carry over of tryptophan to the final extract, resulting in falsely high values for the amine. A modification of the original method is described, incorporating ion‐exchange chromatography, which gives complete separation of these components. Using this method, tryptamine is found neither in the brain of normal guinea pigs, nor in animals treated with l‐tryptophan. It is found only when l‐tryptophan is administered following pretreatment with an amine oxidase inhibitor.
BIOCHEMICAL EVIDENCE FOR A SECRETORY ROLE OF THE PINEAL BODY. OXIDATION OF [1‐14C]‐ AND [6‐14C]GLUCOSE IN VITRO BY PINEAL BODY, PITUITARY, AND BRAIN FROM YOUNG AND ADULT ANIMALS*
Authors: Krass Melvin E. , LaBella Frank S.
Published: October 2006

The conversion of [1‐14C] label from glucose to 14CO2in vitro by bovine pineal bodies was 7‐24 times as great as that of [6‐14C]. These values for C‐1/C‐6 oxidation ratios are similar to those found for all known endocrine tissues and in contrast to those for brain which range from 1.0 to 1.4. Total glucose oxidation, both C‐1 and C‐6, and C‐1/C‐6 ratios were lower in pineal bodies from adult (3‐8 years) than from young (5‐10 months) animals. Total glucose oxidation by the posterior pituitary was lower in the adult than in the young, generally lower in the anterior pituitary of the adult, and higher in the brain of the adult. Epinephrine, 10−4m, increased the oxidation by pineal tissue of [1‐14C] by 170 per cent and of [6‐14C] by 46 per cent. The relatively high C‐1/C‐6 ratios found for pineal tissue are indicative of an operative hexosemonophosphate pathway, which we have previously suggested to be correlated with hormone secretion and/or storage. The present findings provide biochemical support for the hypothesis that the pineal body has an endocrine function in mammals.
THE EFFECT OF PHYSOSTIGMINE AND NEOSTIGMINE ON THE CONCENTRATION OF GLYCOGEN IN VARIOUS BRAIN STRUCTURES OF THE RAT
Authors: Mršulja B. , Terzić M. , Varagić V. M.
Published: October 2006

Abstract—

Hypothalamus, mesencephalon, cerebral cortex, cerebellar cortex and medulla oblongata of the rat brain contain varying amounts of glycogen. The highest concentration was found in the medulla, and the lowest in the hypothalamus.

Low doses of physostigmine produced a significant decrease in the concentration of glycogen in mesencephalon, cerebral cortex, cerebellar cortex and medulla. Higher doses of physostigmine were necessary to produce glycogenolysis in the hypothalamus. In the first four structures glycogen stores were almost equally sensitive to the action of physostigmine. Neostigmine did not affect brain glycogen. The glycogenolytic effect of physostigmine was dose‐dependent.

Both atropine and propranolol were found to block the glycogenolytic effect of physostigmine in brain.

It is concluded that probably both cholinergic and adrenergic processes participate in the glycogenolytic effect of physostigmine. It is suggested that physostigmine initiates the cholinergic processes which then trigger adrenergic processes.
FETTSÄUREN UND ALDEHYDE VON GEHIRNPHOS‐PHATIDEN WÄHREND DER FÖTALEN UNO FRÜH‐KINDLICHEN ENTWICKLUNG DES MENSCHEN12
Authors: Altrock K. , Debuch H.
Published: October 2006

Zusanunenfassung—

Es wurden fotale Gehirne mens III, V, VI und VII, sowie ein Neugeborenen‐Gehirn, zwei Gehirne von Säuglingen im Alter von 3 bzw. 7 Monaten und ein kindliches Gehirn im Alter von 13 Monaten im Hinblick auf den Gehalt an Gesamtlipoiden, Neutrallipoiden und “Rohphosphatiden” untersucht. Die Fettsáuren und Aldehyde der Phosphatide wurden gaschromatographisch analysiert. Es zeigte sich, daβ sowohl bei den Fettsäuren als auch bei den Aldehyden die C14‐kettigen Anteile im Beobachtungszeitraum abnehmen, während die C18‐Anteile insgesamt zunehmen. Anders verhalten sich sowohl die C18‐Monoenfettsauren als auch die C18‐Monoenaldehyde, deren Anteil sich‐beginnend vom jüngsten Fötalgehirn bis zur Geburt verringert und dann in der Myelinisierungsperiode wieder ansteigt. Die C20‐ und C22‐Polyenfettsäuren bleiben im untersuchten Zeitraum fast konstant. Bei den Aldehyden sind auβer den C16‐ und C18‐gesätt., sowie den C18‐Monoenaldehyden praktisch keine anderen Aldehyde auffindbar.
INHIBITION OF NOREPINEPHRINE RE‐UPTAKE BY ANGIOTENSIN IN BRAIN1
Authors: Palaic D. , Khairallah P. A.
Published: October 2006

—A method for perfusion of rat brain ventricles accompanied by electrical stimulation of right vagus nerve was used in the study of the re‐uptake mechanism of norepinephrine in rat brain. Tritiated norepinephrine was injected into the left lateral brain ventricle. After a 1‐hr equilibration period, the brain was perfused, and effluent was collected and assayed for norepinephrine, normetanephrine and acid metabolites by means of column chromatography and liquid scintillation counting. Electrical stimulation of central end of right vagus nerve produced a significant release of norepinephrine and decrease of acid metabolites; this indicates a shift of catecholamines to extracellular sites. Angiotensin (200 ng/min) added to the perfusion fluid potentiated the effect of nerve stimulation. Cocaine, desmethylimipramine and phenoxybenzamine greatly reduced the release of norepinephrine from brain tissue. None on these drugs potentiated the effect of angiotensin. It is concluded that angiotensin prevents re‐uptake of norepinephrine released by nerve stimulation. As a naturally occurring, physiologically active peptide, angiotensin seems to be highly specific in modulation of adrenergie neurotransmission, allowing increased extraneuronal accumulation of neurotransmitter.
STEROLS WITH 29, 28 AND 27 CARBON ATOMS METABOLICALLY RELATED TO CHOLESTEROL, OCCURRING IN DEVELOPING AND MATURE BRAIN1
Authors: Weiss J. F. , Galli G. , Paoletti E. Grossi
Published: October 2006

Abstract—

Brain sterols from chick embryos (11 and 18 days of incubation) and mature rats, previously injected with [2‐14C]mevalonate, were analysed.

Acetate derivatives of the sterols were chromatographed on Silica Gel:Celite:AgNO3 columns. Sterol fractions were assayed for radioactivity and the amounts determined by gas chromatography. Sterol structures were elucidated by gas chromatography‐mass spectrometry. The method used allowed the identification of some sterols representing no more than 0‐01 per cent of the total mixture.

The following brain sterols were identified: cholesterol, cholestanol, cholest‐5,24‐dien‐3β‐ol (desmosterol); 4,4′‐dimethyl‐cholest‐8‐en‐3β‐ol, 4α‐methyl‐cholest‐8‐en‐3β‐ol, cholest‐8‐en‐3β‐ol, 4,4′‐dimethyl‐choIest‐8,24‐dien‐3β‐ol, 4α‐methyl‐cholest‐8,24‐dien‐3β‐ol, cholest‐8,24‐dien‐3β‐ol and cholest‐7,24‐dien‐3β‐ol. Small amounts of other sterols including polyhydroxy sterols, were also detected. There were no qualitative differences in the sterols detected in developing and mature brain. In the developing chick brain, cholesterol represented approximately 90 per cent of the total sterols. In the mature rat brain, cholesterol accounted for 98 per cent of the sterols.

The adult rat brain, as well as the embryonic chick brain, demonstrated the capacity to incorporate mevalonate into cholesterol precursors and cholestanol. The sterols retaining the double bond in the lateral chain, that is, those of the Δ8,24 series with 29, 28 and 27 carbon atoms and desmosterol, were highly labelled compared with the other identified intermediates. The possibility, supported by our data, that a preferential biosynthetic route for cholesterol exists in brain, is discussed.
ELEVATED PLASMA PHENYLALANINE CONCENTRATION AND LYSINE INCORPORATION INTO RIBOSOMAL PROTEIN OF DEVELOPING BRAIN
Authors: Swaiman K. F. , Hosfield W. B. , Lemieux B.
Published: October 2006

Abstract—

Hyperphenylalaninemia was induced in 7‐day‐old rabbits over a 6‐hr period by intraperitoneal injection of phenylalanine.

l‐[U‐14C]Lysine was injected intraperitoneally into these rabbits and into a control group. The rate of incorporation of l‐[U‐14C]lysme into brain ribosomal protein was decreased during a 5‐hr period in the presence of elevated plasma phenylalanine concentrations. Lysine transport from the peritoneum to the plasma was unaffected by the high plasma phenylalanine concentrations.
ADRENAL CATECHOLAMINES AND RELATED CHANGES DURING DIFFERENT PHASES OF MORPHINE ADMINISTRATION—A HISTOCHEMICAL STUDY
Authors: Ray A. K. , Mukherji M. , Ghosh J. J.
Published: October 2006

Abstract— (1) Acute morphine treatment of rats reduced the total catecholamine content as well as the noradrenaline content of the adrenal gland. This was accompanied by increased ATPase activity and increased calcium content of the medullary cells.

(2) After chronic morphine treatment, the total catecholamine content remained more or less unaltered, but the noradrenaline content was markedly increased together with the noradrenaline‐containing areas, in comparison with what was observed in control animals. The ATPase activity of the medullary cells was found to be diminished along with the decreased calcium content.

(3) In nalorphine‐induced abstinence, a decrease in total catecholamine content together with a reduction of noradrenaline content and of noradrenaline‐containing areas were observed. ATPase activity was also found to be increased with increased calcium content.
ESTERASES OF DEVELOPING HUMAN BRAIN*
Authors: Barron K. D. , Bernsohn J.
Published: October 2006

Abstract The free and bound nonspecific esterases occurring in, respectively, the saline and triton X‐100 extracts of adult and developing human brain were studied by starch gel electrophoresis (zymograms). Zymograms of the free esterase fraction visualized with NA as substrate were qualitatively similar at 5‐12 days of age to the electrophoretic patterns observed in adult material. In both adult and developing brain, zymograms of bound esterase resembled those of the free enzyme, the major difference being the presence in the former of a slow, broad, anodic zone of diethyl‐p‐nitrophenyl phosphate‐inhibited enzyme.

Esterases characteristic of adult white matter and having preferential affinity for alpha‐naphthylpropionate, alpha‐naphthyl butyrate and alpha‐naphthyl valerate were not identified in infant brain until about 4 months postnatal age.

A far‐moving, anodic enzyme was distinctly evident in zymograms of brains of less than 1 month of age. This enzyme hydrolysed NP, NB, and NV more actively than alpha‐naphthyl acetate. It was present in the adult brain but, in contrast to the infant, was no longer electrophoretically‐separable from another enzyme which had greater affinity for NA and had previously been designated the A10 band.

Quantitative assays demonstrated that the bound esterase increased in cerebral and cerebellar cortex during development. In contrast, the proportion of free to bound esterase showed little change in white matter.

Acetylcholinesterase and butyrylcholinesterase zymograms became identical to adult patterns from 1 to 4 months of age.

Thiolacetic acid esterase was present at 38 weeks gestation.

Some functional and anatomical correlations were attempted in explanation of the biochemical observations.
ISOLATION AND DETERMINATION OF NON‐DIFFUSIBLE SIALOFUCOHEXOSAMINOGLYCANS DERIVED FROM BRAIN GLYCOPROTEINS AND THEIR ANATOMICAL DISTRIBUTION IN BOVINE BRAIN
Authors: Brunngraber Eric G. , Brown Barbara D. , Aguilar Virginia
Published: October 2006

Abstract— Glycoproteins in brain tissue were assayed by determining the amount of N‐acetylneuraminic acid (NANA), hexosamine, hexose, and fucose present in glycopeptides released by the proteolytic action of papain on the defatted protein residue that remains after treatment of the sample with chloroform‐methanol (2:1 and 1:2, v/v). Diffusible and non‐diffusible glycopeptides (sialofucohexosaminoglycans) were released by proteolysis. The procedure demonstrated that successive treatment of brain tissue with chloroform‐methanol (2:1, v/v) and chloroform‐methanol (1:2, v/v) removed all of the gangliosides present in the tissue.

A 1 hr autolysis of rat brain tissue had no effect on the amount of glycopeptides recovered from the tissue. The carbohydrate composition of the non‐diffusible sialofucohexosaminoglycans was also unaffected.

Areas of the brain that are enriched in neuronal cell bodies contained a higher concentration of gangliosides and glycoproteins than areas that consist largely of myelinated fibre tracts. On the other hand, there was a greater concentration of glycoprotein relative to that of gangliosides in areas that consist predominately of myelinated fibre tracts and glia than in areas enriched in neuronal cell bodies. The concentration of non‐diffusible sialofucohexosaminoglycans in whole bovine brain was less than that in whole rat brain. The non‐diffusible sialofucohexosaminoglycans from whole bovine brain contained less fucose and NANA per mole of hexosamine and hexose than non‐diffusible sialofucohexosaminoglycans isolated from whole rat brain. The non‐diffusible sialofucohexosaminoglycans isolated from bovine cerebral white matter were lower in fucose and NANA content per mole of hexose and hexosamine than those isolated from other brain areas. It is suggested that the fucose and NANA content of the non‐diffusible sialofucohexosaminoglycans associated with myelinated axons and (or) glia is less than that of the non‐diffusible sialofucohexosaminoglycans associated with the nerve cell body.
MYELIN METABOLISM IN VITRO IN EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS1
Authors: Smith Marion E.
Published: October 2006

Abstract— Spinal cord slices from rats in different stages of allergic encephalomyelitis (EAE) were incubated with [U‐14C]glucose. Normal rats and rats injected with Freund's adjuvant served as controls. The slices were fractionated by a discontinuous sucrose gradient into purified myelin and a heavy membrane residue, the lipids and proteins were extracted, and their specific activities were determined. Uptake of 14C into myelin lipids was depressed in the rats with acute EAE, while an increase was shown in myelin protein and heavy membrane lipids and proteins. The increased synthesis in non‐myelin fractions was ascribed to invasion of metabolically active cells. The depression in myelin lipid synthesis occurred early in the disease before lesions appeared or the inflammatory reaction became widespread. Myelin from guinea pigs with acute EAE resulting from injection of a purified basic protein also showed a depression of uptake in both lipids and proteins. It is suggested that a metabolic insult as a result of the immunological process is dealt the oligodendroglial cells early in the course of the disease which leads to a weakening of the myelin sheath and subsequent phagocytosis of myelin.
AN INTRALAMINAR ANALYSIS OF β‐GLUCURONIDASE IN CEREBRAL CORTEX OF RAT1
Authors: Allen N. , DeKirmenjian H. K.
Published: October 2006

Abstract— Activities of β‐glucuronidase were measured microchemically in the rat within cortical layers and subcortical white matter of somatosensory and visual cortex and the dorsal hippocampus. Distributions were related to histological composition, densities of myelinated fibers, and lysosome content as indicated by acid phosphatase staining. Three zones of relatively high activities were noted. The first corresponded to the pia‐arachnoid and has been related to lysosmal particles within pericytes and macrophages of the meninges and in the pial cells. A second peak appeared in layer V and correlated well with the presence of neuronal lysosomes as detected by histochemical reaction. A third contribution was related to the presence of myelinated fibre bundles and white matter. Data from the literature and from unpublished results were cited to support the conclusion that nonlysosomal sources of enzyme in white matter included a major component from particles sedimenting with the microsomal fraction and a small component from myelin.
TRANSPORT OF 14C INCORPORATED PROTEIN IN THE CORTICOSPINAL TRACT OF THE RAT BRAIN
Authors: Foulkes J. A. , Robinson N.
Published: October 2006

Abstract— The origin of fibres of a corticospinal pathway in rat brain was located by cortical ablation and Marchi staining and also by electrical stimulation of the motor cortex.

Enzyme changes investigated histochemically over 0–14 days post‐injection of 5 μ10.15 m NaCl into the neocortex indicated that very little apparent disturbance of nerve cell metabolism beyond a narrow band adjacent to the path of the microneedle within the cortex had occurred. [14 C]Leucine as a precursor of protein synthesis was used to study incorporation of the amino acid into protein. At the site of injection the maximum level of labelled protein was recorded at 30 min post‐injection, the level decreasing to less than 2 per cent of this at 6 hr.

The subsequent axonal flow of labelled protein along the corticospinal pathway was investigated during the period 15 min to 21 days post‐injection. Within 24 hr increasing amounts of labelled proteins were measured caudally, but not more than 6 per cent had migrated beyond 5 mm from the site of injection. At 3 days this percentage had increased to 14.6 per cent, the labelled proteins being distributed in progressively decreasing amounts to a further 13 mm caudal. Very little change from this position was seen during the following 18 days.
THE EFFECT OF HYPERBARIC OXYGEN ON METABOLISM OF THE GABA SHUNT1
Authors: Myles W. S. , Wood J. D.
Published: October 2006

Abstract— —The GABA‐α‐ketoglutarate transaminase pathway provides, in the brain, an alternative route for the conversion of α‐ketoglutarate to succinate. In vitro experiments with rat brain homogenates and either [14C]GABA or [14C]α‐ketoglutarate showed the percentage metabolism via the transaminase pathway to be about 17 per cent in air and 10 per cent oxygen at high pressure. Since the transaminase shunt was more sensitive to hyperbaric oxygen than the direct pathway, these results do not support the hypothesis of an alternative route operating under conditions of oxygen poisoning.
AMINO ACIDS AND CEREBRAL EXCITABILITY1
Authors: Gallagher B. B.
Published: October 2006

Abstract— —Seizure threshold, measured with hexafluorodiethyl ether, was shown to be reduced in immature albino rats fed a diet containing excess tryptophan. Similar diets containing excess glycine, serine, leucine, valine or lysine had no effect on seizure threshold. Previous studies had shown phenylalanine, tyrosine and methionine to enhance cerebral excitability with the same technique. The increased cerebral excitability was shown to occur within 24 hr following diet supplementation with phenylalanine. Brain concentration of hexafluorodiethyl ether was identical in control and experimental animals, although the experimental animals had lowered seizure thresholds; this established an alteration in cerebral excitability rather than variation in tissue penetration by the convulsant. Alterations were found in blood and brain ammonia in serine, lysine and methionine supplemented animals. Brain glutamate and glutamine were lowered in methionine‐supplemented animals; however, it was concluded that this effect was not causally related to the increased cerebral excitability.
THE INFLUENCE OF EXCESS METHIONINE ON THE FREE AMINO ACIDS OF BRAIN AND LIVER OF THE WEANLING RAT*
Authors: Daniel R. G. , Waisman H. A.
Published: October 2006

Abstract— —High circulating levels of l‐methionine produced by inclusion in the diet or parenteral injection of the amino acid caused alterations in the free amino acid pattern of liver and brain tissues. Acute effects following l‐methionine injection were more pronounced than those following long term feeding where adaptation played a role. The net effect following parenteral injection was to increase the total free amino acids of liver while decreasing those of brain.

Individually, hepatic levels of aspartic acid, threonine, serine, glutamine, glutamic acid, glycine, and alanine were depressed while levels of taurine, cystathionine, methionine, lysine, and ornithine were markedly elevated. Brain levels of aspartic acid, threonine, serine, glutamic acid, glycine, alanine, and γ‐aminobutyric acid were markedly depressed and increased levels of cystathionine, methionine, lysine, and glutamine were observed.

A generalized aminoaciduria occurred shortly after excessive methionine intake.

Disruption of the free amino acid pools was of two kinds. The first depended on the continued presence of excess l‐methionine, the second did not.
EFFECTS OF DIFFERENT SUPPLEMENTS TO LOW PROTEIN AND POOR QUALITY PROTEIN DIETS ON PERFORMANCE AND BRAIN ENZYMES IN THE ALBINO RAT1
Authors: Rajalakshmi R. , Pillai K. R. , Ramakrishnan C. V.
Published: October 2006

Abstract—

Groups of albino rats were fed low and high protein diets and the former group was fed with different supplements. The supplements used were niacin, pyridoxine and glutamic acid. A low protein diet was found to decrease the activities of l‐glutamate‐NAD‐oxidoreductase and l‐glutamate‐1‐carboxy‐lyase in the cerebrum; this confirmed the results of previous work in this laboratory. Addition of glutamic acid to a low protein diet was found to reverse the effects of a low protein diet to some extent.

Groups of animals were fed kodri (Paspalum scorbiculatum), a millet deficient in lysine, with or without lysine itself or foodstuffs rich in it, e.g. moth bean (Phaseolus aconitifolius Jacq.), peas (Pisum sativuni) and skim milk powder. When combined, the groups fed on the lysine or lysine‐source supplemented diets were found to perform better in a water maze on the basis of the relative ease with which they could reverse a previous learned pattern. They also had higher activities of l‐glutamate‐NAD‐oxidoreductase and l‐glutamate‐1‐carboxy‐lyase than groups with no lysine or lysine source added. There was no significant difference between the groups receiving the different lysine supplements.
COMPARISON OF THE BEHAVIOUR OF A SOLUBLE AND A MEMBRANE‐BOUND ENZYME IN TRANSECTED PERIPHERAL NERVES
Authors: Skangiel‐Kramska Jolanta , Niemierko Stella , Lubińska Liliana
Published: October 2006

Abstract—

Phosphoglucoisomerase (PGI), a soluble enzyme, and AChE, a membrane‐bound enzyme were studied in transected peroneal nerves of dog and in isolated segments of these nerves. Although activities of both enzymes increased at the ends of transected nerves, marked differences in their behaviour were observed. The increment in AChE activity was much sharper than that of PGI and continued to grow with time whereas the increase in PGI developed fully within the initial hours after transection and did not change thereafter.

In an isolated nerve segment AChE accumulated at both ends with a concomitant decrease in the middle part, whereas changes in PGI activity appeared only in the terminal parts, the rest of the nerve remaining at the normal level. The terminal increase of PGI did not, contrary to that of AChE, depend on the length of the isolated segment.

The changes in PGI activity may be features of a local peritraumatic reaction whereas those of AChE indicate involvement of the whole segment along which the enzyme containing organelles are transported.
WALLERIAN DEGENERATION: A SEQUENTIAL PROCESS
Authors: Simon R. G. , Wade R. R. , DeLarco J. E. , Baker May‐Louise
Published: October 2006

—A study of Wallerian degeneration as a function of time has indicated that the degenerative process is sequential, that it begins with myelin that was laid down last and progresses toward myelin that was laid down first. It is proposed that Wallerian degeneration is a relatively poor model for the study of degeneration of nervous tissue in many pathological conditions.
INFLUENCE OF THYROID ON FORMATION OF MYELIN LIPIDS 1
Authors: Walravens P. , Chase H. P.
Published: October 2006

—The formation of lipids found primarily in the myelin sheath was investigated in rats made hypothyroid, at birth. A marked reduction in cerebroside, sulphatide, and cholesterol of brains was found in 18‐day‐old hypothyroid animals. These lipids were also reduced, although to a lesser degree, in 30‐day‐old ex‐hypothyroid animals allowed to return to the euthyroid state at age 18 days.

The onset of formation of sulphatide in vivo was delayed in the hypothyroid animals. Sulphatide formation reached a peak at a later time and was greatly reduced in comparison to control animals. The activity in vitro of galactolipid sulphotransferase, which forms sulphatide from cerebroside and PAPS, was reduced only when exogenous PAPS was not added to the assay medium. This finding suggests a defect in the formation of PAPS from ATP and sulphate in the hypothyroid brain. In addition, T3 (tri‐iodothyronine) had a stimulatory effect in vivo of formation brain sulphatide when administered to rats during the first 5 days of life.
TRITON SOLUBILIZED ACETYLCHOLINESTERASE OF BRAIN
Authors: Ho I. K. , Ellman G. L.
Published: October 2006

—The total AChE of brain can be readily extracted into aqueous Triton X‐100. By column chromatography of these extracts a preparation was obtained at least six times as active as the original material and in yields of 60‐80 per cent of the original amounts. The molecular weight of this material was estimated to be over 200,000. When brain tissue was treated with venom or bacterial protease, a water‐soluble AChE was obtained with an overall purification of 150‐fold. The most active preparation of AChE hydrolysed 880 μ‐moles of acetylthiocholine/hr/mg of protein. The molecular weight of this preparation was estimated to be about 100,000. The enzyme which was extracted by Triton X‐100 is probably the precursor of the more water‐soluble enzyme that can be prepared from brain tissue by treatment with venom or protease.
DNA AND DNA‐POLYMERASE ACTIVITY IN CHICKEN BRAIN REGIONS DURING ONTOGENY1
Authors: Margolis F. L.
Published: October 2006

Abstract—

The DNA content of cerebral hemispheres, optic lobes, cerebellum and remainder was determined in chicken brains from the 11th day of embryonic life to 6 weeks after hatch. Each region showed a characteristic pattern of variation during development. The cerebellum showed the most rapid and the optic lobes the least rapid rate of DNA increase during the period studied. The concentration of DNA within these regions decreased continuously with age except for that of the cerebellum which passed through a maximum just before hatching.

The nature of the DNA‐polymerase activity in soluble extracts from these brain regions seemed to be similar to the properties reported for this enzyme activity in other vertebrate tissues. Glycerol was stimulatory and denatured DNA was preferred to native DNA as primer. The requirements for magnesium ions and DNA were absolute. The requirement for deoxynucleoside triphosphates indicated this to be a replicative rather than a terminal addition enzyme. At nearly every age the level of enzyme activity was highest in extracts from the embryonic cerebellum.

The particulate fraction from brain homogenates decreased the DNA‐polymerase activity observed in soluble brain extracts. Data are presented which indicate that this inhibition was the result of dephosphorylation of the deoxynucleoside triphosphate substrates by an ATPase in the brain particulate fraction whose activity increases during ontogeny.
THE ISOLATION OF GAMMA‐GLUTAMYL PEPTIDES FROM MONKEY BRAIN
Authors: Reichelt K. L
Published: October 2006

Abstract— The isolation and identification of the following gamma‐glutamyl peptides from the brain of Macaca irus and Cercopithecus ethiops is reported: glutamyl‐glutamine, glutamyl‐glycine, glutamyl‐alanine, glutamyl‐valine, glutamyl‐isoleucine, glutamyl‐glutamate, glutamyl‐serine and glutamyl‐alanyl‐glycine.