bluuebunny/crossref_metadata_2025 huggingface dataset:
A systematic review of primary healthcare provider education and training using the Chronic Care Model for Childhood Obesity
Authors: Jacobson D. , Gance‐Cleveland B.
Published: July 2010

The purpose of this systematic review was to examine 15 studies which evaluated interventions aimed at improving primary care providers' identification, assessment, prevention and/or management of obesity in children and adolescents. Interventions were evaluated in terms of length, components addressing nutrition, physical activity and behavioural counselling consistent with expert recommendations, and inclusion of components of the Chronic Care Model. Overall, training interventions were delivered face to face or in a combination of lecture, assigned readings, preceptorship with experienced providers, and critiqued evaluations of interactions of the provider with the patient and family. Many studies incorporated training of providers as an initial step prior to delivering an obesity intervention for children and adolescents measuring weight loss and behaviour change as outcomes. Each study was evaluated for components of the Chronic Care Model. The interventions most frequently utilized the elements of self‐management support (69%), decision support (100%), delivery system support (77%) and clinical information systems (23%). Although science in this area is emerging, results suggest that intervention programmes that included more components of the Chronic Care Model were more effective.
Prevalence of obesity in Switzerland 1992–2007: the impact of education, income and occupational class
Authors: Faeh D. , Braun J. , Bopp M.
Published: July 2010

Prevalence of excess weight varies substantially by socioeconomic position (SEP). SEP can be defined with different indicators. The strength of the association of SEP with excess weight differs by SEP indicator, between populations and over time. We examined the prevalence of overweight and obesity (body mass index 25–29.9 and ≥30 kg m−2) in Switzerland by educational level, household income tertile and occupational class (three categories for each indicator). Self‐reported data stem from four cross‐sectional population surveys including 53 588 persons aged between 25 and 74 years. The overall prevalence of overweight increased between 1992 and 2007 from 37.4% to 41.4% in men and from 18.8% to 21.9% in women. Obesity prevalence increased from 7.2% to 9.7% in men and from 5.4% to 8.6% in women. Inequalities were calculated with multivariable logistic regression. Inequalities were larger in women than in men and for obesity than for overweight. However, overweight and obesity inequalities did not significantly change over time, despite overall increasing prevalence. Although all SEP indicators were independently associated with excess weight, the association was strongest with education, particularly in women. Programmes and policies aimed at preventing excess weight should target individuals with low education early in life.
Research Note: Fieldwork, supervision and trust
Authors: Michaud Jean
Published: July 2010

In this research note I reflect upon my different experiences as a researcher with ethnic minorities in Southeast Asia, from my years as a postgraduate student to my current work as a professor. From being a graduate student, to supervising them, I have learned many lessons about graduate fieldwork. Nowadays, I pass these on to supervisees as best I can. I consider it my professional and personal duty to actively warn, inform and prepare young anthropologists about to leave for their masters' and doctoral field research in China, Vietnam and Laos about the field locations to which they are travelling, the political negotiations that they will need to undertake, and the cultural, economic and political differences they will encounter. I also stress that the anthropology that is played out in the field in socialist settings is not necessarily that which we read about in textbooks.
Muscle moment arms and function of the siamang forelimb during brachiation
Authors: Michilsens Fana , Vereecke Evie E. , D’Août Kristiaan , Aerts Peter
Published: July 2010

Moment arms have an important modulating impact on muscle function, as they represent the capacity of the muscle to convert muscle action into limb movements. In the current paper, we provide muscle moment arm data of the forelimb of four siamangs, collected by detailed dissections on unfixed cadavers. The aim of this study is to assess the role of different forelimb muscles during brachiation. Moment arm data are compared with similar published data of non‐brachiating primates such as macaques, chimpanzees and humans. Our data show that shoulder adductors and endorotators and the elbow flexors are built for force generation, whereas the shoulder abductors, flexors and exorotators are best suited to gain speed and to change direction. Compared to non‐brachiating species, both elbow and wrist flexors are particularly noticeable in terms of moment of force‐generating capacity. However, the moment of force‐generating capacity of the elbow extensor is not negligible, which indicates that the triceps also plays an active role, especially at the end of the support phase. Except for the elbow flexors, all muscles reach their maximum moment of force‐generating capacity during the support phase of brachiation. When brachiating on a more complex setup, the siamang will flex the elbows to angles that induce maximum moment arms as well.
EFFECTS OF HYPOTHYROIDISM AND UNDERNUTRITION ON DNA CONTENT AND THYMIDINE KINASE ACTIVITY DURING CEREBELLAR DEVELOPMENT IN THE RAT1,2
Authors: Weichsel M. E. , Dawson L.
Published: July 2010

—The effects of hypothyroidism and several degrees of undernutrition on the development of cerebellar weight, DNA, and thymidine kinase activity were studied in young rats ranging in age from 2 to 22 days. Early propylthiouracil treatment caused a delayed cerebellar cell multiplication. The activity of cerebellar thymidine kinase was suppressed at ages 2 and 5 days and was in excess of control values on days 15 and 22, thus resulting in a delay in the developmental spectrum for thymidine kinase, and extending the time span of activity beyond that of controls. Undernutrition led to varying degrees of reduced cell proliferation at experimental ages 5, 12, and 19 days. Cerebella from the most undernourished animals showed significant differences from controls in thymidine kinase activity at ages 5 and 12 days. Comparisons between sub‐groups from within the oversized litters at 5 and 12 days suggested that changes in thymidine kinase activity relate to the degree of undernutrition to which the sub‐group is subjected and that during development there may be a critical degree of undernutrition at which a particular essential enzyme becomes affected.

This study emphasizes the biochemical similarities and differences between neonatal hypothyroidism and undernutrition, while pointing out the difficulties which exist in biochemical separation of components of the two conditions. Further evidence is presented that thymidine kinase is responsive to hormonal stimuli during cerebellar development and may play an important role in the regulation of DNA biosynthesis in brain as well as other organs.
A NEW CHEMICAL METHOD FOR QUANTIFYING MELANIN1
Authors: Das K. C. , Abramson M. B. , Katzman R.
Published: July 2010

—A direct chemical method for the estimation of absolute amounts of synthetic melanin is established by the use of sodium borohydride, a mild reducing agent for the ketonic or aldehyde carbonyl group. Sodium borohydride not only solubilized the melanins obtained from various precursors, but it also restored aromatic characteristics in the absorption spectra. The solubilized melanin has also been used with a radio‐assay method for quantification of synthetic melanin. With this method of solubilization, the presence of lipids or proteins does not alter the linearity of the assay. The limiting amount of melanin detected by this method is 4‐5 μg/ml of the final solution.
EFFECT OF DELTA‐9‐TETRAHYDROCANNABINOL ON GANGLIOSIDES AND SIALOGLYCOPROTEINS IN SUBCELLULAR FRACTIONS OF RAT BRAIN
Authors: Sarkar C. , Ghosh J. J.
Published: July 2010

—The present paper reports the result of studies undertaken to determine the effects of the in vivo administration of Δ9‐THC on the ganglioside and sialoglycoprotein contents of rat brain subcellular fractions. Results indicate that the administration of the drug under both acute and chronic conditions brings about characteristic changes in the sialoglycoproteins and ganglioside content in all the subcellular fractions. Both sialoglycoproteins and ganglioside contents were markedly increased in microsomal and synaptosomal fractions and decreased in the mitochondrial fractions although the increase in the synaptosomal fractions has been found to be most striking.

After chronic treatment, both ganglioside and sialoglycoprotein content did not change substantially in all the fractions except for a small increase in case of synaptosomal fractions.
THE BIOSYNTHESIS OF OCTOPAMINE‐CHARACTERIZATION OF LOBSTER TYRAMINE β‐HYDROXYLASE
Authors: Wallace B. G.
Published: July 2010

—Tyramine β‐hydroxylase catalyzes the biosynthesis of octopamine in the lobster nervous system. This enzyme has been characterized and a rapid microassay, based on the enzymic release of tritiated water from [1,2‐(side chain)3H] tyramine, has been developed. Lobster tyramine β‐hydroxylase resembled mammalian dopamine β‐hydroxylase. The most conspicuous differences were that the lobster enzyme was inhibited by anions, particularly fumarate, and had a higher affinity for substrates. Tyramine β‐hydroxylase activity was present in both particulate and soluble fractions of homogenates of the lobster nervous system. Bound activity, extracted by repeated freezing and thawing, was partially purified. The enzyme had the following properties: (1) The optimum pH for the conversion of tyramine to octopamine was 7·4. (2) The apparent Michaelis constant for tyramine was 0·15 mmand for ascorbic acid was 0·2 mmat pH 6·6. (3) The purified enzyme was inhibited by salts; the degree of inhibition was sensitive to the anion and decreased in the order chloride ⋍ fumarate > sulphate > acetate. (4) Tyramine β‐hydroxylase was inhibited by metal chelating agents and by cupric sulphate at concentrations greater than 10−4m;N‐ethylmaleimide had no significant effect on activity in concentrations up to 3 mm. (5) The purified enzyme also β‐hydroxylated dopamine to form norepinephrine, with an apparent Michaelis constant of 0·24 mm. This activity co‐purified with tyramine β‐hydroxylase, suggesting that a single enzyme catalyzed both reactions.
CYCLIC ADENOSINE 3′,5′‐MONOPHOSPHATE FORMATION IN GUINEA‐PIG BRAIN SLICES: EFFECT OF H1‐ AND H2‐HISTAMINERGIC AGONISTS
Authors: Dismukes K. , Rogers M. , Daly J. W.
Published: July 2010

—A variety of histamine analogs elicit accumulations of radioactive cyclic AMP in guinea‐pig neocortical and hippocampal slices labelled during a prior incubation with [14C]adenine. The H1agonist, 2‐aminoethylthiazole, elicits accumulation of cyclic AMP in neocortical and hippocampal slices both in the absence or presence of adenosine. The presence of adenosine increases the maximum response to 2‐aminoethylthiazole and decreases the EC50by nearly 10‐fold. In the absence of adenosine the effects of 2‐aminoethylthiazole are antagonized in hippocampal slices by bothd‐brompheniramine and metiamide, while in the presence of adenosine onlyd‐brompheniramine is an effective antagonist. The H2‐agonist, 4‐methylhistamine, elicits a somewhat smaller accumulation of cyclic AMP than does 2‐aminoethylthiazole in both cortical and hippocampal slices. In the presence of adenosine the response to 4‐methylhistamine is enhanced, but is markedly lower than that seen with the combination of adenosine and 2‐aminoethylthiazole. The dose‐response relationship for 4‐methylhistamine in the presence of adenosine appears in hippocampal slices to consist of two components. The response to 4‐methylhistamine in the absence of adenosine is blocked by metiamide, while in the presence of adenosine the response is partially blocked by both H1and H2‐antagonists. The accumulation of cyclic AMP elicited by histamine is greatly increased by adenosine but the EC50is not significantly decreased. The results suggest that (i) both H1‐ and H2‐receptors regulate cyclic AMP‐formation in the central nervous system, (ii) the synergism between adenosine and histamine is mediated primarily by interaction with H1‐receptors and (iii) that adenosine greatly increases the affinity of the H1‐receptors for both H1and H2‐agonists without affecting its affinity for histamine.
AXONAL TRANSPORT OF SULFATED GLYCOPROTEINS AND MUCOPOLYSACCHARIDES IN THE GARFISH OLFACTORY NERVE
Authors: Elam J. S. , Peterson Nancy W.
Published: July 2010

—Application of 35SO4 to the olfactory mucosa of the long‐nosed garfish is found to label sulfated macromolecules which are transported down the olfactory nerve. The transported molecules pass along the nerve as a discrete peak whose leading edge has a transport velocity of 206 ± 6 mm/day. A large portion of the radioactivity from the peak is deposited along the axon. At 2 days after isotope application 83% of the total nerve radioactivity is in the axons and the remaining 17% has accumulated at the terminals in the olfactory bulb. Characterization of sulfated material in the migrating peak indicates that both sulfated glycoproteins (isolated as glycopeptides) and mucopolysaccharides, including chondroitin sulfate and heparan sulfate, are undergoing transport.
Differences in Anionic Dependence of the Synaptic Efflux of d‐Aspartic Acid and γ‐Aminobutyric Acid
Authors: Naalsund Liv Unni , Fonnum Frode
Published: July 2010

Abstract: The synaptosomal effluxes of d‐aspartate and γ‐aminobutyric acid (GABA) induced by a substitution of the Cl‐ ions with propionate in the incubation medium were measured in preparations of hippocampal tissue homogenates. The efflux of aspartate was significantly higher than spontaneous efflux at 125 mM Cl‐ (normal = 144 mM) and was increased with decreasing Cl‐ concentration. GABA efflux was much less sensitive to a reduction in Cl concentration than D‐aspartate. The efflux was Ca2+‐dependent in both cases.
Glycine Antagonists Structurally Related to 4,5,6,7‐Tetrahydroisoxazolo[5,4‐c]pyridin‐3‐ol Inhibit Binding of [3H]Strychnine to Rat Brain Membranes
Authors: Braestrup Claus , Nielsen Mogens , Krogsgaard‐Larsen Povl
Published: July 2010

Abstract:[3H]Strychnine binding to rat pons + medulla membranes was used as a measure of glycine receptors or glycine receptor‐coupled chloride channels in vitro. A series of compounds structurally related to 4,5,6,7–tetrahydroisoxazolo[5,4–c]pyridin‐3–ol (THIP), which previously were shown to antagonize glycine responses in cat spinal cord, inhibited [3H]strychnine binding in micromolar concentrations. The most potent of these glycine antagonists, 5,6,7,8–tetrahydro‐4H‐isoxazolo[3,4–d]azepin‐3–ol (iso‐THAZ), was also the most potent inhibitor of [3H]strychnine binding, with aKiof 1,400 nM. TheKivalue for strychnine was 7.0 nM, whereas theKivalue for the mixed γ‐aminobutyric acid (GABA)/glycine antagonist 3α‐hydroxy‐16–imino‐5β‐17–aza‐androstan‐11–one (RU 5,135) was only 4.6 nM. Sodium chloride (1,000 mM) enhanced the affinity of strychnine, brucine, isostrychnine, and the nonselective GABA antagonist pitrazepin for [3H]strychnine binding sites, whereas the affinities of glycine, β‐alanine, and taurine were reduced. These sodium chloride shifts, however, were not predictive of antagonist or agonist properties, since the sodium chloride shift for the glycine antagonist iso‐THAZ and of the other THIP‐related antagonists were similar to those of the glycine‐like agonists. The various sodium chloride shifts show that different groups of ligands bind to glycine receptor sites in different ways.
Inhibition by K+ of Na+‐Dependent D‐Aspartate Uptake into Brain Membrane Saccules
Authors: Danbolt Niels C. , Storm‐Mathisen Jon
Published: July 2010

Abstract: Na+‐dependent uptake of dicarboxylic amino acids in membrane saccules, due to exchange diffusion and independent of ion gradients, was highly sensitive to inhibition by K+. The IC50 was 1–2 mM under a variety of conditions (i.e., whole tissue or synaptic membranes, frozen/thawed or fresh, D‐[3H]aspartate (10–1000 nM) or L‐[3H]glutamate (100 nM), phosphate or Tris buffer, NaCl or Na acetate, presence or absence of Ca2+ and Mg2+). The degree of inhibition by K+ was also not affected on removal of ion gradients by ionophores, or by extensive washing with H2O and reloading of membrane saccules with glutamate and incubation medium in the presence or absence of K+ (3 mM, i.e., IC70). Rb+, NH4+, and, to a lesser degree Cs+, but not Li+, could substitute for K+. [K+] showed a competitive relationship to [Na+]2. Incubation with K+ before or after uptake suggested that the ion acts in part by allowing net efflux, thus reducing the internal pool of amino acid against which D‐[3H]aspartate exchanges, and in part by inhibiting the interaction of Na+ and D‐[3H]aspartate with the transporter. The current model of the Na+‐dependent high‐affinity acidic amino acid transport carrier allows the observations to be explained and reconciled with previous seemingly conflicting reports on stimulation of acidic amino acid uptake by low concentrations of K+. The findings correct the interpretation of recent reports on a K+‐induced inhibition of Na+‐dependent “binding” of glutamate and aspartate, and partly elucidate the mechanism of action.
Metabolic Pools of ATP in Cultured Bovine Adrenal Medullary Chromaffin Cells
Authors: Corcoran James J. , Korner Mira , Caughey Byron , Kirshner Norman
Published: July 2010

Abstract: Cultured bovine adrenal chromaffin cells contain a pool of ATP sequestered within the chromaffin vesicles and an extravesicular pool of ATP. In a previous study it was shown that the turnover of ATP in the extravesicular pool was biphasic. One phase occurred with a t1/2 of 3.5–4.5 h whereas the second phase occurred with a t1/2 of several days. The studies described here were undertaken to characterize further the vesicular and extravesicular pools of ATP by examining the effects of metabolic inhibitors, adenosine, and digitonin on ATP utilization and subcellular localization immediately after and 48 h after labeling with [3H]adenosine and 32Pi. Immediately after labeling a combination of cyanide, 2‐deoxy‐D‐glucose, the β‐glucono‐l,5‐lactone resulted in a 90–95% depletion of the labeled ATP but only a 25% depletion of the endogenous ATP within 30 min. Forty‐eight hours after labeling, addition of the inhibitors resulted in a 70% depletion of the [3H]ATP but only a 25% depletion of the [32P]ATP and endogenous ATP. Addition of 10 μM adenosine to the media resulted in a similar loss of [3HJATP in cells examined immediately after or 48 h after labeling. Adenosine increased the amounts of [32P]ATP when added immediately after labeling but had no effect on the [32P]ATP content when added 48 h after labeling. Permeabilization of the plasma membrane by treatment with digitonin resulted in a loss of 90–95% of the labeled ATP but only 20% of the endogenous ATP in cells examined immediately after labeling and in a 79% loss of [3H]ATP, a 32% loss of [32P]ATP, and a 23% loss of endogenous ATP in cells examined 48 h after labeling. These studies show that ATP contained within chromaffin vesicles is metabolically inert and does not exchange readily with cytosolic ATP, but they do not differentiate extravesicular pools of labeled ATP. Calculation of ATP disappearance after abrupt cessation of ATP production indicates that cultured adrenal chromaffin cells utilize ATP at a rate of 0.24 nmol/min/106 cells, corresponding to a turnover time of 12.5 min for the extravesicular pool.
NAD+Glycohydrolase of the Plasma Membrane Prepared from Glial and Neuronal Cells
Authors: Honma Takeshi , Mandel Paul
Published: July 2010

Abstract:NAD+glycohydrolase (EC 3.2.2.5) activity was detected in the plasma membrane prepared from the primary culture of rat astrocytes. The enzyme has a broad optimum pH range. From the kinetic analysis, a Michaelis constant of 91.2 μMand a maximum velocity of 0.785 μmol/min/mg protein were obtained. ADPribose exhibited a competitive inhibition with respect to NAD. The inhibition by nicotinamide was shown to be of a noncompetitive type. ATP and GTP were found to be competitive inhibitors. NAD+glycohydrolase activity was not detected in the plasma membrane prepared from the primary culture of neuronal cells of chick embryos.
Characterization of the A1Adenosine Receptor‐Adenylate Cyclase System of Cerebral Cortex Using an Agonist Photoaffinity Ligand
Authors: Stiles Gary L. , Daly Daniel T. , Olsson R. A.
Published: July 2010

AbstractEndogenous adenosine acting via A1adenosine receptors is capable of inhibiting adenylate cyclase activity and neurotransmitter release in the brain. In this report, we describe the synthesis and attributes of a new series of A1adenosine receptor agonists. One of these, [125I]N6‐2‐(4‐amino‐3‐iodophenyl)ethyladenosine, can be used as a radioligand and another, [125I]N6‐2‐(4‐azido‐3‐iodophenyl)ethyladenosine, as a photoaffinity probe. The unlabeled ligand,N6‐2‐(4‐aminophenyl)ethyladenosine, and its iodinated product are full agonists, inhibiting cyclic AMP production in rat cerebral cortex membranes to the same extent as the prototypic A1agonistN6‐R‐1‐phenyl‐2‐propyladen‐osine. These new ligands are not substrates for adenosine deaminase. The new photoaffinity azide described here labels an Mr38,000 protein that displays all the pharmacological characteristics expected of the A1adenosine receptor. This is the same molecular‐weight protein previously described using a cross‐linking radioligand. This new azide compound demonstrates a 15‐fold higher efficiency of incorporation, making it the photoaffinity probe of choice for tissues containing low concentrations of A1adenosine receptors.
Photoaffinity Labeling of the 5‐HydroxytryptamineIAReceptor in Rat Hippocampus
Authors: Ransom Richard W. , Asarch Kenneth B. , Shih Jean C.
Published: July 2010

Abstract1‐[2‐(4‐Azidophenyl)ethyl]‐4‐(3‐trifluoromethylphenyl)piperazine (p‐azido‐PAPP) inhibits [3H]5‐hydroxytryptamine ([3H]5‐HT) binding to 5‐HTIAand 5‐HTIBsites in rat brain with equilibrium dissociation constants (KD) of 0.9 nMand 230 nM, respectively. [3H]p‐Azido‐PAPP was synthesized and its reversible and irreversible binding properties to the hippocampal 5‐HTIAsite characterized. [3H]p‐Azido‐PAPP labeled a single class of sites in rat hippocampal membranes with aKDof 1 nMand a maximal binding density of 370 fmol/mg protein. The pharmacological profile of [3H]p‐azido‐PAPP binding was consistent with the radioligand's selective interaction with the 5‐HTIAreceptor. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis of membranes preincubated with [3H]p‐azido‐PAPP and irradiated showed a major band of incorporation of radioactivity at approximately 55,000 daltons. This incorporation could be blocked when membranes were incubated with 1μMof several agents that have high affinity for 5‐HTIAsites [5‐HT, 8‐hydroxy‐2‐(di‐n‐propylamino)tetraline, TVX Q 7821, spiperone, buspirone,d‐lysergic acid diethylamide, metergoline]. The results indicate that on photolysis [3H]p‐azido‐PAPP irreversibly labels a polypeptide that is, or is a subunit of, the 5‐HTIAreceptor in rat hippocampus.
Optimisation of Conditions for Solubilisation of the Bovine Dopamine D2 Receptor
Authors: Hooper R. J. L.
Published: July 2010

Abstract Solubilisation of the dopamine D2 receptor from a membrane preparation of bovine corpus striatum using cholate and NaCl was independently optimised with regard to cholate (0.2%, wt/vol), NaCl (1.5 M), and membrane protein (4 mg/ml) concentrations. A maximum solubilisation yield of 58% was obtained and receptors were measured using a [3H]spiperone binding assay incorporating a polyethylene glycol precipitation step. Soiubilisation was confirmed by ultracentrifugation studies, passage of the receptor through fine‐pore filters, increased thermolability, and by retention of the prelabelled receptor on gel filtration. The soluble receptor showed saturability and reversibility of binding. Displacement of [3H]spiperone from the soluble receptor by competing compounds correlated closely with displacement from the membrane‐bound receptors. [3H]‐Spiperone binding was found to be pH‐dependent, with maximum binding occurring at pH 7.8. A comparison of solubilisation was made with six other agents both with and without added NaCl and it was concluded that the cholate/ NaCl solubilisation system provides an efficient, inexpensive, and reliable method for the preparation of functional bovine dopamine D2 receptors.
Characterization of Brain Calpains
Authors: Nilsson E. , Karlsson J.‐O.
Published: July 2010

Abstract A new, simple one‐step procedure [Karlsson et al. Biochem. J. 231, 201–204 (1985)] for the separation of calpains I and II was used prior to the characterization of these enzymes from rabbit brain, using alkali‐denatured casein as the substrate. Enzyme activity was dependent on Ca2+ ions and free ‐SH groups and was maximal around pH 7.4. Incubation of calpains I and II with Ca2+ in the absence of substrate led to a rapid loss of enzyme activity. Enzyme activity was linear at room temperature and millimolar Ca2+ concentrations. However, when incubation ofcalpain I was performed with micromolar Ca2+ concentrations at room temperature proteolytic activity exhibited a lag period of approximately 10 min. This activation period was not as evident with calpain II.
Modulatory Effects of Thyroxine Treatment on Central and Peripheral Benzodiazepine Receptors in the Rat
Authors: Gavish M. , Weizman A. , Okun F. , Youdim M. B. H.
Published: July 2010

AbstractThe effects of 10 days of D‐thyroxine (T4) treatment on central benzodiazepine (BZ) receptors in the brain and on peripheral‐type BZ binding sites in the heart, kidney, and testis of rats were studied. The experimental hyperthyroidism resulted in an increase in the density of cortical central BZ receptors, without any alteration of the affinity of the receptors to [3H]flunitrazepam. The increase in cortical central BZ receptors was also accompanied by the up‐regulation of peripheral BZ binding sites in the heart, kidney, and testis. The affinity of the peripheral BZ binding sites for the Iigand [3H]PK 11195 was not affected by T4treatment in any of these three organs. The increase in the density of brain cortical central BZ receptors was less prominent than the increase in the peripheral BZ binding sites. The modulatory effect of T4treatment on central and peripheral BZ receptors might be attributed to the direct interaction of the thyroid hormone at these sites or might reflect a physiological compensatory adaptation mechanism to thyrotoxicosis associated with hypermetabolism, anxiety, and stress.
Isolation and Characterization of Multilayered Sheath Membrane Rich in Glucocerebroside from Shrimp Ventral Nerve
Authors: Okamura Nobuyuki , Yamaguchi Hisao , Stoskopf Michael , Kishimoto Yasuo , Saida Takahiko
Published: July 2010

Abstract A membrane fraction rich in glucocerebroside was isolated from homogenates of ventral nerves of pink shrimp (Penaeus duorarum) by sucrose gradient centrifugation. The membrane fraction was observed at 0.15 M sucrose and was rich in lipids (lipid/protein ratio ∼15:1). Electron microscopy showed that the fraction was derived from myelin‐like multilayered glial membrane ensheathing axons, which has morphological similarities to myelin. Most of the lipids in shrimp nerve, including glucocerebroside, sphingomyelin, phosphatidylcholine, phosphatidylserine, phosphatidylethanolamine, and ethanolamine‐plasmalogen, as well as cholesterol, appeared to be concentrated in this fraction. The fatty acids of these phospholipids were exclusively saturated or monounsaturated with C14‐C26 chain lengths. The aldehyde moiety of plasmalogens contained only saturated C14‐C18 carbon chains. Like glucocer ebrosides, the sphingoid base of sphingomyelin consisted mainly of C14‐C16 sphingenines and sphinganines, but they also contained significant amounts of C19 and C20 sphinganines. Sodium dodecyl sulfate‐polyacrylamide gel electrophoresis of the proteins in this fraction showed several bands in the 23,000–85,000 Mr range. Radioimmunoassay, however, did not show cross‐reactivity with antibodies to myelin basic protein. The functional role of this membrane in relation to mammalian myelin is discussed.
Time Course of the Metabolite Patterns of Intraventricularly Injected [3H]Noradrenaline in Rat Brain Regions
Authors: Köster G.
Published: July 2010

AbstractIn the hypothalamus, septum, pons with medulla, and hippocampus regions of rat brain, the level of radioactivity of [3H]noradrenaline and of five of its metabolites were determined up to 6 h after intraventricular injection of the tritiated amine. The following main results were found: (a) In anterior hypothalamus and septum, the [3H]noradrenaline level declined in two phases. (b) Similar turnover curves were obtained for the primary deaminated metabolites, with almost the same final half‐lives as for [3H]noradrenaline. (c) The level of the initial methylation product, normetanephrine, also showed a biphasic decline, which did not correspond to that of [3H]noradrenaline but rather was faster throughout the experiment. (d) The final metabolites (i.e., the glycol sulfates) reached maximal levels in hypothalamus and septum earlier than in other regions. Thereafter, their levels declined with almost similar rates in all areas tested, but always faster than the [3H]noradrenaline level. The following conclusions were drawn: (a) In areas rich in catecholaminergic nerve terminals, there seems to be a site, in addition to the vesicular storage pool, that accumulates exogenous noradrenaline and then releases it with relatively short half‐lives. The contents of primary deaminated metabolites followed the turnover of [3H]noradrenaline at both sites. (b) Exogenous [3H]noradrenaline seems to be methylated at two extraneuronal sites, which are distinguished by the rates of subsequent deamination. The size of the pool of slowly deaminated [3H]normetanephrine that is formed immediately after [3H]noradrenaline injection determined the apparent turnover of this product throughout the experiment and, thus, like the final metabolites, reflects for several hours the initial degradation of the unstored [3H]noradrenaline, rather than the metabolism of the stored amine. (c) The methylating space linked to the slow deamination and the second site of noradrenaline accumulation were more marked in areas rich in noradrenergic nerve terminals than in perikarya or in nonaminergic regions.
Solubilization of the Benzodiazepine/γ‐Aminobutyric Acid Receptor Complex: Comparison of the Detergents Octylglucopyranoside and 3‐[(3‐Cholamidopropyl)‐Dimethylammonio] 1‐Propanesulfonate (CHAPS)
Authors: Hammond James R. , Martin Ian L.
Published: July 2010

AbstractOctylglucopyranoside (OCTG) was three times more efficient than 3‐[(3‐cholamidopropyl)‐dimethylammonio] 1‐propanesulfonate (CHAPS) in solubilizing the benzodiazepine (BDZ)/γ‐aminobutyric acid (GABA) receptor complex from rat cerebellar synaptic membranes. OCTG‐solubilized receptor preparations had ligand binding characteristics that were significantly different from those of the CHAPS‐solubilized receptors. The inclusion of phospholipids in the solubilization media improved the binding characteristics of both soluble receptor preparations and appeared absolutely necessary for the maintenance of chloride facilitation of flunitrazepam (FNZ) binding to OCTG‐solubilized receptors. FNZ and ethyl‐β‐carboline‐3‐carboxylate bound to OCTG‐solubilized preparations with equilibrium dissociation constants of 2.2 nMand 1.6 nM, respectively, and chloride (150 mM) and GABA (100 μM) + chloride facilitated the binding of FNZ by 15% and 55%, respectively; these ligand binding characteristics are similar to those of membrane‐located BDZ receptors. Cartazolate, a pyrazolopyridine that facilitated the binding of FNZ to membrane‐located and CHAPS‐solubilized receptors, did not facilitate FNZ binding to OCTG‐solubilized receptors. These results are discussed in terms of an interaction between the membrane lipid phosphatidylserine (PS) and cartazolate; PS appears to have the capacity to inhibit the effects of cartazolate on FNZ binding. Storage of the soluble receptor preparations for 24 h at 4° resulted in the loss of several characteristic BDZ receptor binding properties. Incorporation of the OCTG‐solubilized receptor complex into liposomes prevented these losses but this procedure did not protect the CHAPS‐solubilized receptors. We conclude that OCTG may have some advantages over CHAPS as the detergent of choice for the solubilization and reconstitution in liposomes of a functional BDZ/GABA receptor‐chloride ionophore complex.
α1‐Adrenergic Receptors in Neuronal Cultures from Rat Brain: Increased Expression in the Spontaneously Hypertensive Rat
Authors: Feldstein Judith B. , Pacitti Anthony J. , Sumners Colin , Raizada Mohan K.
Published: July 2010

Abstract Neuronal cells in primary culture from 1‐day‐old brains of normotensive, Wistar‐Kyoto strain (WKY) and spontaneously hypertensive (SH) rats have been utilized to study the expression of α1‐adrenergic receptors. Binding of a selective α1 antagonist, [125I]2‐[β‐(4‐hydroxy‐3‐iodophenyl)‐ethylaminomethyl]‐tetralone ([125I]HEAT) to neuronal membranes prepared from primary brain cultures of WKY and SH rats was 75–80% specific, rapid, and time‐dependent although the binding was 1.5–2 times higher in neuronal membranes from SH rat brain cultures. Kinetic analysis of the association and dissociation data demonstrated no significant differences between rat strains. Competition‐inhibition experiments provided IC50 values for various antagonists and agonists in the following order: prazosin < phentolamine < yohimbine < phenylephrine < norepinephrine < propranolol, suggesting that [125I]‐HEAT bound selectively to α1‐adrenergic receptors. Scatchard analysis of the binding data provided straight lines for both strains of rats, indicating the presence of a homogeneous population of binding sites. It also showed that the increase in the binding in neuronal cells from SH rat brains over those from normotensive WKY controls was a result of an increase in the number of α1‐adrenergic receptors. Incubation of neuronal cultures from both strains of rats with phenylephrine, an α1‐adrenergic agonist, caused a time‐ and dose‐dependent decrease in the binding of [125I]HEAT. This decrease was due to a decrease in the number of α1‐adrenergic receptors. In conclusion, we demonstrated that the expression of α1‐adrenergic receptors in neuronal cultures of SH rat brain was increased compared with neuronal cultures from normotensive controls. We suggest that the elevated number of these receptors in neurons from the brains of SH rats is an intrinsic property of these cells and therefore provides an etiological basis for the predisposition of these animals to the hypertensive state.
Neocortical Cholinergic Enzyme and Receptor Activities in the Human Fetal Brain
Authors: Perry Elaine K. , Smith Carthage J. , Atack John R. , Candy John M. , Johnson Mary , Perry Robert H.
Published: July 2010

AbstractIn the human fetus, obtained postmortem at estimated gestational ages of 8–22 weeks, biochemical activities of cortical choline acetyltransferase (ChAT) and acetylcho‐linesterase (AChE) were comparable to those of adult brain tissue. In contrast cholinergic receptor binding, including muscarinic Ml and M2 subtypes (measured by displacement of [3H]N‐methylscopolamine with, respectively, pirenzepine and carbachol) and [3H]nicotine (putative nicotinic) binding were undetectable before 13–14 weeks and even at 22 weeks were substantially (three‐ to fourfold) below the respective adult values. Cortical ChAT activity decreased significantly with gestational age whereas binding to the three receptors, including the proportion M1/M2, increased significantly. AChE was present at all ages investigated as the two molecular monomeric (G1) and tetrameric (G4) forms. The proportion of G4, which was much more soluble in fetal compared with adult cortex, increased approximately threefold. Histochemically AChE, although intense in the nucleus of Meynert, was generally confined to subcortical white matter at early fetal developmental periods, appearing later in the cortex localized to nerve fibres and occasional cell bodies. These observations suggest that during the second trimester of human fetal development, cortical cholinergic function may be preceded by relatively high ChAT activity and paralleled not only by increasing receptor binding but also by a proportional increase in the tetrameric form and histochemical reactivity of AChE.
High‐Resolution Proton Magnetic Resonance Analysis of Human Cerebrospinal Fluid
Authors: Petroff O. A. C. , Yu R. K. , Ogino T.
Published: July 2010

AbstractHigh‐resolution proton magnetic resonance spectroscopy was used to analyze human cerebrospinal fluid obtained from patients with several neurological problems. The major metabolites measured included glucose, lactate, glutamine, citrate, inositol, acetate, creatine, creatinine, β‐hydroxybutyrate, alanine, and pyruvate. A drug vehicle, propylene glycol, was also measured. Alterations in the cerebrospinal fluid of these metabolites provided information concerning metabolism of the brain. Magnetic resonance spectroscopy offered a simple and rapid means of assessing these and other exogenous and endogenous compounds in diseases affecting the nervous system.
Synthesis of Quinolinic Acid by 3‐Hydroxyanthranilic Acid Oxygenase in Rat Brain Tissue In Vitro
Authors: Foster Alan C. , White Robert J. , Schwarcz Robert
Published: July 2010

In mammalian peripheral organs, 3‐hydroxy‐anthranilic acid oxygenase (3HAO), catalyzing the conversion of 3‐hydroxyanthranilic acid to quinolinic acid, constitutes a link in the catabolic pathway of tryptophan to NAD. Because of the possible involvement of quinolinic acid in the initiation of neurodegenerative phenomena, we examined the presence and characteristics of 3HA0 in rat brain tissue. A simple and sensitive assay method, based on the use of [carboxy‐14C]3‐hydroxy‐anthranilic acid as a substrate, was developed and the enzymatic product, [14C]quinolinic acid, identified by chro‐matographic and biochemical means. Kinetic analysis of rat forebrain 3HAO revealed aKmof 3.6 ± 0.5 μMfor 3‐hydroxyanthranilic acid and aVmaxof 13.1± 9.5 pmol quinolinic acid/h/mg tissue. The enzyme showed pronounced selectivity for its substrate, since several substances structurally and metabolically related to 3‐hydroxyanthranilic acid caused <25% inhibition of activity at 500 μM. Both the Fe2+dependency and the distinct subcellular distribution (soluble fraction) of brain 3HAO indicated a close resemblance to 3HAO from peripheral tissues. Examination of the regional distribution in the brain demonstrated a 10‐fold variation between the region of highest (olfactory bulb) and lowest (retina) 3HAO activity. The brain enzyme was present at the earliest age tested (7 days postnatum) and increased to 167% at 15 days before reaching adult levels. Enzyme activity was stable over extended periods of storage at — 80°C. Taken together, these data indicate that measurements of brain 3HA0 may yield significant information concerning a possible role of quinolinic acid in brain function and/or dysfunction.
Effects of Purine Nucleotides on the Binding of [3H]Cyclopentyladenosine to Adenosine A‐l Receptors in Rat Brain Membranes
Authors: Williams Michael , Braunwalder Albert
Published: July 2010

Adenine nucleotides displace the binding of the selective adenosine A‐l receptor ligand [3H]cyclopentyl‐adenosine (CPA) to rat brain membranes in a concentration‐dependent manner, with the rank order of activity being ATP > ADP > AMP. Binding was also displaced by GTP, ITP, adenylylimidodiphosphate (AppNHp), 2‐meth‐ylthioATP, and the β‐γ‐methylene isostere of ATP, but was unaffected by the α‐β‐methylene isosteres of ADP and ATP, and UTP. At ATP concentrations >100 μM, the inhibitory effects on CPA binding were reversed, until at 2 mMATP, specific binding of CPA was identical to that seen in controls. Concentrations of ATP >10 mMtotally inhibited specific binding. Inclusion of the catabolic enzyme adenosine deaminase in the incubation medium abolished the inhibitory effects of ATP, indicating that these were due to adenosine formation, presumably due to ectonucleotidase activity. The inhibitory effects were also attenuated by the α‐β‐methylene isostere of ATP, an ectonucleotidase inhibitor. Adenosine deaminase, α‐β‐methylene ATP (100 μM), and β‐γ‐methylene ATP (100 μM) had no effect on the “stimulatory” phase of binding, although GTP (100 μM) slightly attenuated it. Comparison of the binding of [3H]CPA in the absence and presence of 2 mMATP by saturation analysis showed that theKDand apparent Bmaxvalues were identical. Examination of the pharmacology of the control and “ATP‐dependent” CPA binding sites showed slight changes in binding of adenosine agonists and antagonists. The responses observed with high concentrations of ATP were not observed with GTP, AppNHp, the chelating agents EDTA and EGTA, or inorganic phosphate. The divalent cations Mg2+and Ca2+at 10 mMattenuated the stimulatory actions of high (2 mM) concentrations of ATP, whereas EGTA and EDTA (10 mM) enhanced the “stimulatory” actions of ATP. EDTA (10 mM) abolished the inhibitory effects of ATP, indicating a specific dependence on Mg2+for the inhibitory response. The effects of ATP on [3H]CPA binding were reversible for antagonists but not agonists. The mechanism by which ATP reverses its own inhibitory action on adenosine A‐l radioligand binding is unclear, and from the observed actions of the divalent cations and chelating agents probably does not involve a phosphorylation‐dependent process.
Adenosine Inhibition of Calmodulin‐Sensitive Adenylate Cyclase from Bovine Cerebral Cortex
Authors: Yeager Robert E. , Nelson Richard , Storm Daniel R.
Published: July 2010

Calmodulin (CaM)‐sensitive adenylate cyclase has recently been purified extensively from bovine brain. In this study, the sensitivity of the CaM‐sensitive adenylate cyclase to adenosine and adenosine analogs was examined. The highly purified enzyme preparation retained sensitivity to inhibition by adenosine and adenosine analogs with ribose ring modifications, but not to those with purine ring modifications. Adenosine inhibition of this enzyme was not dependent on GTP and was noncompetitive with respect to ATP. Enzyme that had been dissociated from functional guanine nucleotide binding protein interactions by gel filtration in the presence of the zwitterionic detergent 3‐[3‐(cholamido‐propyl)‐dimethylammonio]‐propanesulfonate and Mn2+retained sensitivity to adenosine inhibition. TheKifor adenosine inhibition of the CaM‐sensitive adenylate cyclase was approximately 2.6 × 10‐4M. 5′‐Guanylylimi‐dodiphosphate and CaM did not affect theKiof 3′‐deoxy‐adenosine for the enzyme, but the presence of Ca2+in the millimolar range raised theKiby a factor of 5. These results show that the CaM‐sensitive form of adenylate cyclase from bovine brain is subject to adenosine inhibition, and strongly suggest that this inhibition is due to interaction of ligands with a purine‐specific (“P”) site located on the catalytic subunit of the enzyme.
Posttranslational Modification of Calmodulin in Rat Brain and Pituitary
Authors: Murtaugh Timothy J. , Wright Lynda S. , Siegel Frank L.
Published: July 2010

The posttranslational modification of calmodulin has been studied in six brain regions and the anterior pituitary. Carboxylmethylation, calmodulin converting enzyme, and calmodulin (lysine) N‐methyltransferase activities were determined. Incubation of calmodulin with cytosolic extracts of these tissues in the presence of the methyl donor [methyl‐3H]‐S‐adenosyl‐l‐methionine and identification of labeled proteins by gel electrophoresis and fluorography indicated that calmodulin is a substrate for protein carboxylmethyltransferase in all tissues tested. In hippocampus, caudate nucleus, cerebral cortex, and anterior pituitary, but not in cerebellum, superior colliculus, brainstem, or diencephalon, a second methylated protein was found when calmodulin was added to incubation mixtures. This protein was shown to be identical to the previously described product of calmodulin converting enzyme. Converted calmodulin was isolated by fast protein liquid chromatography and shown to be des(Lys)calmodulin, lacking the carboxy terminal lysine residue of calmodulin. The anterior pituitary had by far the highest levels of calmodulin converting enzyme; this enzyme, in turn, was identified as a cobaltstimulated carboxylpeptidase B. In contrast to the regional differences in these parameters, the levels of calmodulin (lysine) N‐methyltransferase did not differ greatly among brain regions, although regional differences in the activity of this enzyme were statistically significant.
Production of Monoclonal Antibody to 2′,3′‐Cyclic Nucleotide 3′‐Phosphodiesterase from Bovine Cerebral White Matter
Authors: Fujishiro Masatoshi , Kohsaka Shinichi , Nagaike Kazuhiro , Tsukada Yasuzo
Published: July 2010

Lewis rats were immunized with partially purified 2′,3′‐cyclic nucleotide 3′‐phosphodiesterase (CNPase) from bovine cerebral white matter and the spleen cells were fused with cell of a mouse myeloma cell line (SP‐2). The production of monoclonal antibody was detected by (1) enzyme‐linked immunoadsorbent assay, (2) immunohistochemical staining of bovine cerebrum, (3) Western blotting analysis, and (4) CNPase binding assay. Monoclonal antibody that specifically binds CNPase molecules was obtained. However, the antibody did not suppress the enzyme activity. Western blotting analysis demonstrated that the monoclonal antibody binds both CNa (Wla) and CNb (Wlb). The monoclonal antibody was identified as being of the IgG2c subclass. Immunohistochemical examination revealed that the myelin sheath in the CNS was heavily stained with the monoclonal antibody in several species (bovine, mouse, rat, and human). In contrast, peripheral nervous system myelin was not stained even in bovine tissue. These results suggest that the monoclonal antibody obtained in the present study specifically recognizes the CNPase molecules in the CNS.