bluuebunny/crossref_metadata_2025 huggingface dataset:
Alveolar Hemorrhage After Scuba Diving: A Case Report
Authors: Tsai Ming‐Ju , Tsai Mee‐Sun , Tsai Ying‐Ming , Lien Chi‐Tun , Hwang Jhi‐Jhu , Huang Ming‐Shyan
Published: July 2010

Self‐contained underwater breathing apparatus (scuba) diving is increasingly popular in Taiwan. There are few references in the literature regarding pulmonary hemorrhage as the sole manifestation of pulmonary barotrauma in scuba divers, and no study from Taiwan was found in the literature. We present the case of a 25‐year‐old man who suffered alveolar hemorrhage related to pulmonary barotrauma as a complication of scuba diving. To our knowledge, this is the first case report describing a Taiwanese subject suffering from non‐fatal pulmonary hemorrhage after scuba diving.
Inbreeding effects on a winter squash landrace
Authors: TSIVELIKAS A. L. , KOUTSIKA-SOTIRIOU M. S.
Published: July 2010

Estimates of inbreeding effects in a landrace are necessary in order to acquire information on the presence of different types of gene action for important traits. Twelve lines with different levels of inbreeding coefficients (F=0, 0·25, 0·50 or 0·75) were developed from three phenotypically selected families of a winter squash landrace (Cucurbita moschataDuchesne) between 2000 and 2002 in the area of Thermi-Thessaloniki, Greece. During 2003, a field experiment was established at this location to evaluate the lines. The agronomical characters measured were: the number and weight of total commercial fruits, days to first female blossom, seed weight, size of pollen grains and water-stress tolerance. Comparisons were also made of morphological characters, the dry matter, the total soluble solids and the pH of fruits. Lines with inbreeding coefficientF=0·50 were found to have the highest values for most of the measured characteristics. Significant family×inbreeding interactions were found, revealing different trends for the linear, quadratic and cubic components of each family with inbreeding coefficients. ThreeF=0·50 lines selected from within each representative family were evaluated along with four winter squash landraces from theC. moschatacollection of the Greek Gene Bank, during 2004 in the area of Thermi. TheseF=0·50 lines showed a superior performance of three components contributing to yield, indicating that one generation of selfing improved the agronomic performance maintaining concurrently the substantial characteristics of the landrace.
Elliptic instability of a stratified fluid in a rotating cylinder
Authors: GUIMBARD D. , LE DIZÈS S. , LE BARS M. , LE GAL P. , LEBLANC S.
Published: July 2010

In this paper, we analyse the characteristics of the elliptic instability in a finite cylinder in the presence of both background rotation and axial stratification. A general formula for the linear growth rate of the stationary sinuous modes is derived including viscous and detuning effects in the limit of small eccentricity. This formula is discussed and compared to experimental results which are obtained in a cylinder filled with salted water for two different eccentricities by varying the stratification, the background rotation and the cylinder rotation. A good agreement with the theory concerning the domain of instability of the sinuous modes is demonstrated. Other elliptic instability modes, oscillating at the cylinder angular frequency are also evidenced together with a new type of instability mode, which could be connected to a centrifugal instability occurring during the experimental phase of spin-up. The nonlinear regime of the elliptic instability is also documented. In contrast with the homogeneous case, no cycle involving growth, breakdown and re-laminarization is observed in the presence of strong stratification. The elliptic instability in a stratified fluid seems to yield either a persistent turbulent state or a weakly nonlinear regime.
China in the conception of international society: the English School's engagements with China
Authors: ZHANG XIAOMING
Published: July 2010

Since Martin Wight's famous LSE lectures in the late 1950s, the English School scholars have brought China into the conception of international society. As the English School scholars have been ‘inventing’ an international society, China's status in the conception, or conceptions of international society has also been invented and reinvented. The Chinese case vividly demonstrates how a non-European (or non-Western) country, as one of ‘the others’, has been dealt with and brought into the conceptualisation of international society by the English School. China's status in the conception of international society, to a great extent, has been invented by some of the English School scholars with Eurocentric bias.
The dynamics of syntax acquisition: facilitation between syntactic structures
Authors: KEREN-PORTNOY TAMAR , KEREN MICHAEL
Published: July 2010

This paper sets out to show how facilitation between different clause structures operates over time in syntax acquisition. The phenomenon of facilitation within given structures has been widely documented, yet inter-structure facilitation has rarely been reported so far. Our findings are based on the naturalistic production corpora of six toddlers learning Hebrew as their first language. We use regression analysis, a method that has not been used to study this phenomenon. We find that the proportion of errors among the earliest produced clauses in a structure is related to the degree of acceleration of that structure's learning curve; that with the accretion of structures the proportion of errors among the first clauses of new structures declines, as does the acceleration of their learning curves. We interpret our findings as showing that learning new syntactic structures is made easier, or facilitated, by previously acquired ones.
Egg consumption and CHD and stroke mortality: a prospective study of US adults
Authors: Scrafford Carolyn G , Tran Nga L , Barraj Leila M , Mink Pamela J
Published: July 2010

Objective

To evaluate the relationship between egg consumption and CHD and stroke mortality using the Third National Health and Nutrition Examination Survey 1988–1994 (NHANES III) and follow-up survey.

Design

A cross-sectional survey using a stratified, multi-stage probability sample was analysed, adjusting for survey design. Egg consumption was obtained from the FFQ and separated into categories of egg intake. Hazard ratios (HR) were calculated for CHD and stroke mortality using multivariate Cox regression models.

Setting

A health and nutrition survey conducted in the USA from 1988 to 1994 with follow-up through 31 December 2000.

Subjects

The study population included men and women who were free of CVD and had completed a FFQ at baseline.

Results

Multivariate models adjusting for health, lifestyle and dietary factors indicated that ‘high’ egg consumption (≥7 times/weekv. <1 time/week) was not associated with significantly increased CHD mortality (HR = 1·13, 95 % CI 0·61, 2·11 (men); HR = 0·92, 95 % CI 0·27, 3·11 (women)). There was a statistically significant inverse association between ‘high’ egg consumption and stroke mortality among men (HR = 0·27, 95 % CI 0·10, 0·73), but the estimate was imprecise because of sparse data. We did not observe a statistically significant positive association between ‘high’ egg consumption and CHD or stroke mortality in analyses restricted to individuals with diabetes, but these analyses may be limited due to the small number of diabetics.

Conclusions

We did not find a significant positive association between egg consumption and increased risk of mortality from CHD or stroke in the US population. These results corroborate the findings of previous studies.
First estimates of the second‐order ionospheric effect on radio occultation observations
Authors: Vergados Panagiotis , Pagiatakis Spiros D.
Published: July 2010

This study examines the impact of the second‐order ionospheric effect on radio occultation (RO) data products. We propose a new linear combination between dual frequency GPS observables, which retrieves slant total electron content free from the second‐order ionospheric effect. Our STEC values differ from those obtained by independent techniques by a maximum of 3 total electron content units (TECU), depending on the geographic location and geomagnetic activity. Additionally, we suggest an alternative method of computing the second‐order ionospheric delay in RO experiments, which does not require the use of geomagnetic and ionospheric models. First estimates show that the second‐order ionospheric delay for the RO experiments falls within the range [−10, −8] mm, which is of the same order of magnitude with second‐order ionospheric delay estimates from ground‐based experiments. Finally, as a by‐product of our model, we retrieve weighted mean geomagnetic field values, which we compare with theoretical estimates computed by the International Geomagnetic Reference Field‐10 (IGRF‐10) model. Our estimations agree with the IGRF‐10 model between 0.23% and 7.0%.
Recent trends in changes of vegetation over East Asia coupled with temperature and rainfall variations
Authors: Park Hye‐Sook , Sohn B. J.
Published: July 2010

In this study, we investigated whether long‐term normalized difference vegetation index (NDVI) data show climate change signals after the mid‐1990s which are inferred from other studies on changing trends in precipitation and dust frequencies. In doing so, mean NDVI data for the growing seasons (April–October) from 1982 to 2006 were used for examining the spatiotemporal variations in the vegetation over East Asia, in conjunction with precipitation and temperature data. Results indicate that there was a prominent change in the trend of NDVI around the mid‐1990s: a pronounced positive trend over most of the East Asian domain before the mid‐1990s (1982–1996) and a reverse (or weakened) trend after the mid‐1990s (1997–2006). The reverse trend is evident over the higher‐latitude regions north of 50°N and the eastern Mongolian border area. The EOF and SVD analysis suggest that the dominant warming trend until the mid‐1990s led to the increased NDVI over the high‐latitude regions. However, after the mid‐1990s, the reverse NDVI trend found primarily in the east of Lake Baikal and the arid and semiarid regions south of 50°N seems to be closely linked to local precipitation changes occurred abruptly in the mid‐1990s. However, precipitation influences on the reverse NDVI changes are not clear over the high‐latitude regions north of 50°N.
Cloud optical depth retrievals from the Aerosol Robotic Network (AERONET) cloud mode observations
Authors: Chiu J. Christine , Huang Chiung‐Huei , Marshak Alexander , Slutsker Ilya , Giles David M. , Holben Brent N. , Knyazikhin Yuri , Wiscombe Warren J.
Published: July 2010

Cloud optical depth is one of the most poorly observed climate variables. The new “cloud mode” capability in the Aerosol Robotic Network (AERONET) will inexpensively yet dramatically increase cloud optical depth observations in both number and accuracy. Cloud mode optical depth retrievals from AERONET were evaluated at the Atmospheric Radiation Measurement program's Oklahoma site in sky conditions ranging from broken clouds to overcast. For overcast cases, the 1.5 min average AERONET cloud mode optical depths agreed to within 15% of those from a standard ground‐based flux method. For broken cloud cases, AERONET retrievals also captured rapid variations detected by the microwave radiometer. For 3 year climatology derived from all nonprecipitating clouds, AERONET monthly mean cloud optical depths are generally larger than cloud radar retrievals because of the current cloud mode observation strategy that is biased toward measurements of optically thick clouds. This study has demonstrated a new way to enhance the existing AERONET infrastructure to observe cloud optical properties on a global scale.
Definitive evidence of Hesperian basalt in Acidalia and Chryse planitiae
Authors: Salvatore Mark R. , Mustard John F. , Wyatt Michael B. , Murchie Scott L.
Published: July 2010

The surface materials of Acidalia and Chryse planitiae, Mars, have been variably interpreted morphologically as basalt and compositionally as andesite or altered basalt. A thorough survey using the Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) near‐infrared spectrometer reveals olivine and high‐calcium pyroxene signatures in the shallow subsurface exposed by impact craters. These signatures indicate that the near surface of these regions are primarily basaltic in nature and are similar to other regions of Hesperian volcanism across Mars (e.g., Syrtis Major). Previous spectroscopic studies using coarser‐resolution data sets have failed to identify these mafic signatures due to obscuration of the underlying material in addition to the relatively small‐scale exposures in impact craters. The nature of the surficial obscuration material is likely multifaceted and includes the deposition of latitude‐dependent mantling material and the presence of alteration rinds. This observation shows that the northern plains of Mars are basaltic and must be factored into the thermal and surficial evolution of Mars.
Mantle flow pattern and geodynamic cause of the North China Craton reactivation: Evidence from seismic anisotropy
Authors: Zhao Liang , Xue Mei
Published: July 2010

We investigate the mantle flow pattern and geodynamic cause of North China Craton (NCC) reactivation using shear wave splitting measurements from 140 broadband stations. Using a newly developed method for simulating wave propagation in a two‐dimensional anisotropic medium, we first examined the influence of sedimentary structures on SKS splitting measurements. The simulations show that a sedimentary layer, whether isotropic or anisotropic, significantly influences the waveform; however, the shear wave splitting parameters can be retrieved with negligible errors. As a result, this study included new splitting measurements at stations which were deployed within basins and not used previously. Among 121 broadband stations that contribute valid splitting results, 55 stations are newly added which were deployed within basins. This significantly improved the sampling coverage on the NCC. The complicated spatial patterns of the splitting parameters indicate that complex upper mantle deformation has occurred in the NCC. To obtain both deep kinematic and geometric information, we interpret our splitting measurements in the context of new high‐resolution tomographic results for the NCC. By comparing our observations with three end‐member conceptual models (upwelling, wedge flow, and lithospheric delamination), we found that the observed anisotropy pattern beneath the NCC is not completely consistent with any of them. Thus, we prefer a hybrid mantle flow model, where the subduction of the Pacific Plate causes a mantle wedge flow beneath the eastern Archean block and a regional upwelling beneath the central block which has been imaged as a low velocity anomaly in seismic tomography. Thus we speculate that the subduction of the Pacific Plate, compared to the NCC‐Yangtze Craton amalgamation and the India‐Eurasian collision, is most likely the geodynamic cause of the reactivation of the NCC eastern block during the Late Mesozoic to Cenozoic.
Silicate weathering machine at work: Rock magnetic data from the late Paleocene–early Eocene Cicogna section, Italy
Authors: Dallanave Edoardo , Tauxe Lisa , Muttoni Giovanni , Rio Domenico
Published: July 2010

We describe a scenario of climate forcing on sedimentation recorded in the late Paleocene–early Eocene Cicogna marine section from the Belluno Basin (NE Italy). Previously published magneto‐biostratigraphic data revealed that the ∼81 m Cicogna section extends from Chron C25r to Chron C23r spanning the NP7/NP8‐NP12 nannofossil zones (∼52.2–56.6 Ma). Using previously published rock magnetic data, augmented by data from this study, we describe and thoroughly discuss a pronounced increase of hematite (relative to maghemite or magnetite) between ∼54.9 and 54.6 Ma immediately above the Paleocene–Eocene boundary, followed by a second, long‐term increasing trend from ∼54 Ma up to ∼52.2 Ma in the early Eocene. This hematite is essentially of detrital origin, insofar as it is associated with a strong shallow bias of paleomagnetic inclinations, and is interpreted to have formed on land by the weathering of Fe‐bearing silicates and other primary minerals. We speculate that the warm and humid climate typical of the Paleocene–Eocene thermal maximum (PETM, ∼54.9 Ma) as well as of the warming trend leading to the early Eocene climatic optimum (EECO; ∼52–50 Ma) enhanced continental weathering of silicate rocks with the consequent production, transport, and sedimentation of detrital hematite grains. This hypothesis is confirmed by a statistical correlation between the rock magnetic properties and global climate as revealed by a standard benthic oxygen isotope record from the literature. Our temporal coupling between oxidation state of sedimentary magnetic phases and global climate is therefore consistent with the existence in the Paleocene–Eocene of the silicate weathering negative feedback mechanism for the long‐term stabilization of the Earth's surface temperature.
A study in two centres of variations in the time of apical barrier detection and barrier position in nonvital immature permanent incisors
Authors: Kinirons M. J. , Srinivasan V. , Welbury R. R. , Finucane D.
Published: July 2010

Objectives. To study barrier formation in nonvital, immature permanent incisors being treated using the apexification technique in two centres, and to establish the effect of the frequency of change of calcium hydroxide (CaOH) on barrier detection times.

Design. A retrospective study of the time of detection and the position of barriers.

Results. There were no significant differences between the two centres in terms of the average frequency of change of each CaOH dressing, the distribution of barrier detection times or the position of barriers (P > 0·05). There was a total of 107 teeth and the time of barrier detection was significantly earlier in more frequently dressed teeth (P = 0·013). Of the teeth with a barrier detection time of less than 9 months, 60.7% were dressed more frequently than every 3 months, as opposed to 39·1% of teeth with longer barrier times (P = 0·027). The mean time of barrier detection for all cases was 43·3 weeks. The majority of barriers were located at or near the apex.

Conclusion. The frequency of change of CaOH can increase the speed of barrier detection but does not appear to affect the position.
The indwelling ureteric stent: a ‘friendly’ procedure with unfriendly high morbidity
Authors: Richter S. , Ringel A. , Shalev M. , Nissenkorn I.
Published: July 2010

Objective To review the morbidity and complications of ureteric stent insertion and to evaluate specifically the effect of an indwelling ureteric stent on the changes in hydronephrosis after stenting.

Patients and methods In a prospective study, 110 renal units with a stent in place were evaluated in 90 patients. Of the 110 stents, 52 were left in place for 3 months, 23 for 6, 11 for 9, 19 for 12 and five (forgotten stents) for 13–30 months. The patients were followed using plain abdominal X‐ray at 1 and 30 days after stenting. They were further followed using ultrasonography and plain films every 3 months until the scheduled date for stent removal or the appearance of complications.

Results Thirty‐four patients had fever and bacteriuria after stent insertion. Of the 110 stents, 11 (10%) fragmented and nine (8%) migrated. Seventeen patients complained of flank pain on voiding. In 21 renal units (19%) there was no change in the severity of hydronephrosis, whereas in six (5.5%) hydronephrosis developed or worsened after stenting.

Conclusion Although ureteric stenting is undoubtedly an important procedure to relieve ureteric obstruction, the indications for stent insertion should be considered carefully in every patient. The close follow‐up of stented patients is valuable for the early detection of morbidity or complications and in such cases the stent should be removed or exchanged as soon as possible.
NMDA Receptors with Different Sensitivities to Magnesium and Ifenprodil Control the Release of [14C]Acetylcholine and [3H]Spermidine from Rat Striatal Slices in Vitro
Authors: Nicolas C. , Page D. , Carter C.
Published: July 2010

Abstract:KCI (20–100 mM) and W‐methyl‐D‐aspartate (NMDA, 100–1,000 μM) produce concomitant concentration‐dependent increases in the release of previously captured [14C]acetylcholine and [3H]spermidine from rat striatal slices in vitro. The effects of NMDA (300μM) on striatal [14C]acetylcholine and [3H]spermidine release were blocked with equal potencies by the competitive NMDA antagonist CGP 37849, the glycine site antagonist L‐689,560, and the NMDA channel blocker dizocilpine. In contrast, although NMDA‐evoked [14C]acetylcholine release was antagonized by ifenprodil (IC50= 5.3 μM) and MgCl2, (IC50= 200 μM), neither compound antagonized the NMDA‐evoked release of [3H]spermidine at concentrations up to 100 μM(ifenprodil) or 1 mM(MgCl2). Distinct NMDA receptor subtypes with different sensitivities to magnesium and ifenprodil therefore exist in the rat striaturn.
AMPA Receptor Development in Rat Telencephalon: [3H]AMPA Binding and Western Blot Studies
Authors: Hall Randy A. , Bahr Ben A.
Published: July 2010

Abstract: Telencephalic membranes from rats of different embryonic (E16, E19) and postnatal (P2, P7, P14, adult) ages were assessed for α‐[3H]amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid ([3H]AMPA) binding and for immunoreactivity levels of AMPA receptor subunits (GluR1, GluR2/3, and GluR4). In addition, the synaptic markers synaptophysin and NCAM140 (a neural cell adhesion molecule isoform) were examined by immunoblot. The density of [3H]AMPA binding sites increased steadily with advancing age. This increase was due mainly to the development of the large low‐affinity component (KD = 400 nM) that dominates the [3H]AMPA binding profile of adult rat brain membranes. As resolved by two‐site regression analysis, the high‐affinity component (KD = 15 nM) of the [3H]AMPA binding increased by approximately twofold from E16 to adult, whereas the low‐affinity component increased by 25‐fold. Staining for GluR1 and GluR2/3 increased steadily with increasing age at all time points examined; synaptophysin and NCAM140 exhibited similar ontogenic immunostaining profiles. GluR4 immunoreactivity was first evident at P14 and increased by adulthood. These results indicate that AMPA receptor density increases steadily during development and that this increase is coincident with the ontogenic expression of other synaptic components. Furthermore, there is a shift toward a preponderance of low‐affinity [3H]AMPA binding, which occurs during the period when AMPA receptors are being sorted into postsynaptic regions, suggesting that some element of the postsynaptic membrane environment modulates AMPA receptor properties.
Effects of Locally Applied Cocaine, Lidocaine, and Various Uptake Blockers on Monoamine Transmission in the Ventral Tegmental Area of Freely Moving Rats: A Microdialysis Study on Monoamine Interrelationships
Authors: Chen Nian‐Hang , Reith Maarten E. A.
Published: July 2010

Abstract: Microdialysis was used to compare the effect of local perfusion of cocaine with that of functionally similar compounds on extracellular norepinephrine, dopamine, and serotonin (measured simultaneously) in the ventral tegmental area of freely moving rats. Tetrodotoxin (1 µM) potently inhibited both basal and cocaine‐induced dialysate monoamine outputs. The local anesthetic lidocaine produced little or no effect on the monoamine output, whereas all uptake blockers tested (at 0.1–1,000 µM) increased the monoamine output in a dose‐dependent manner. The selective norepinephrine‐uptake blockers desipramine and nisoxetine did not show any selectivity for norepinephrine, whereas the selective serotonin‐uptake blockers fluoxetine and citalopram, as well as the selective dopamine‐uptake blocker GBR 12935, preferentially (but not exclusively) increased their target amine. Cocaine at low concentrations (1–10 µM) increased the three amines similarly, but at higher concentrations (100–1,000 µM) caused a relatively higher dopamine output. A positive relationship between blocker‐induced dialysate norepinephrine and dopamine outputs suggests significant interactions between monoamine systems. The present results indicate that cocaine's action in the ventral tegmental area involves not only a dopamine‐, but also a norepinephrine‐ and a serotonin‐related component, and that cocaine‐induced monoamine increase is independent of its local anesthetic property.
Interactions Between N‐Acetylaspartylglutamate and AMPA, Kainate, and NMDA Binding Sites
Authors: Valivullah H. Mohammed , Lancaster Jean , Sweetnam Paul M. , Neale Joseph H.
Published: July 2010

Abstract: The structure of N‐acetylaspartylglutamate (NAAG) suggests this neuronal dipeptide as a candidate for interaction with discrete subclasses of ionotropic and metabotropic acidic amino acid receptors. A substantial difficulty in the assay of these interactions is posed by membrane‐bound peptidase activity that converts the dipeptide to glutamate and N‐acetylaspartate, molecules that will interfere with receptor assays. We have developed two sets of unique receptor assay conditions and applied one standard assay to measure the interactions, under equilibrium binding conditions, of [3H]kainate, [3H]amino‐3‐hydroxy‐5‐methylisoxazole‐4‐propionic acid ([3H]AMPA), and [3H]CGS‐19755 with the three classes (kainate, quisqualate, and N‐methyl‐d‐aspartate) of ionotropic glutamate receptors, while inhibiting peptidase activity against NAAG. Under these conditions, NAAG exhibits apparent inhibition constants (IC50) of 500, 790, and 8.8 µM in the kainate, AMPA, and CGS‐19755 receptor binding assays, respectively. Glutamate was substantially more effective and less specific in these competition assays, with inhibition constants of 0.36, 1.1, and 0.37 µM. These data support the hypothesis that, relative to glutamate, NAAG functions as a specific, low potency agonist at N‐methyl‐d‐aspartate subclass of ionotropic acidic amino acid receptors, but the peptide is not likely to activate directly the kainate or quisqualate subclasses of excitatory ionotropic receptors under physiologic conditions.
Heat Shock Proteins hsp90 and hsp70 Protect Neuronal Cells from Thermal Stress but Not from Programmed Cell Death
Authors: Mailhos Carolina , Howard M. Keith , Latchman David S.
Published: July 2010

Abstract: Prior exposure to a mild thermal stress can protect neuronal cells from a subsequent more severe stress including high temperature, ischemia, glutamate toxicity, or stimuli inducing apoptosis. Although the protective effect of thermal stress correlates with the elevated expression of the heat shock proteins (hsps), the protective effect of individual hsps has never been directly demonstrated in neuronal cells. Here we show that the constitutive overexpression of either of the major hsps, hsp90 or hsp70, can protect neuronal cells from thermal stress but not from stimuli that induce apoptosis. The possible mechanisms by which thermal stress can protect neuronal cells from apoptosis are discussed.
Protection by Alcuronium of Muscarinic Receptors Against Chemical Inactivation and Location of the Allosteric Binding Site for Alcuronium
Authors: Jakubík Jan , Tuček Stanislav
Published: July 2010

Abstract: We have found earlier that the neuromuscular blocker alcuronium binds to cardiac muscarinic receptors simultaneously with their specific antagonist [3H]methyl‐N‐scopolamine ([3H]NMS) and allosterically increases their affinity to this ligand. Nothing is known about the allosteric site with which alcuronium interacts. To gain an insight, we have now investigated how the binding of [3H]NMS is affected by agents known to modify specific residues in proteins and how their effects are altered by alcuronium. Reagents that covalently modify the tyrosyl residues (p‐nitrobenzenesulfonyl fluoride and 4‐chloro‐7‐nitrobenzofurazan) and the carboxyl groups of aspartate and glutamate [1‐ethyl‐3‐(3‐dimethylaminopropyl)carbodiimide, N,N′‐dicyclohexylcarbodiimide, and N‐ethyl‐5‐phenylisoxazolium‐3′‐sulfonate] blocked the binding of [3H]NMS to receptors in rat heart atria. Their action was probably due to the modification of tyrosyl and aspartyl residues directly in the muscarinic binding sites because it was antagonized by atropine and carbamoylcholine. Alcuronium and gallamine, another allosteric ligand, also protected the [3H]NMS binding sites against the inactivation by tyrosine‐ and carboxyl‐directed chemical modifiers just as well as by benzilylcholine mustard, known to attach covalently to the muscarinic binding sites. Protection by alcuronium has also been observed on cerebrocortical muscarinic receptors. The effect of alcuronium indicates that the drug interferes with the access of chemical modifiers to the muscarinic sites. In view of the unspecific nature of most of the modifiers used (with regard to muscarinic mechanisms), the protection by alcuronium appears to be best explained on the assumption that the drug binds in close vicinity of the “classical” muscarinic site and sterically blocks the access to this site.
Differentiation Effects of Ciliary Neurotrophic Factor on Human Neuroblastoma Cells
Authors: Lawrance G. , Rylett R. J. , Richardson P. M. , Dunn R. J. , Dow K. E. , Riopelle R. J.
Published: July 2010

Abstract: In the human neuroblastoma cell line LA‐N‐2, recombinant rat ciliary neurotrophic factor (CNTF) induced neurite growth and cholinergic differentiation that were both half‐maximally saturated at <100 pM of the neurokine, but was not required for cell survival in serum‐free conditions over a 13‐day period. CNTF markedly stimulated choline acetyltransferase activity and acetylcholine synthesis, whereas high‐affinity choline transport was only slightly enhanced and acetylcholinesterase activity was unchanged. Leukemia inhibitory factor had effects identical to CNTF on neurite growth and choline acetyltransferase activity, but interleukin 6 had no effect. Radioiodinated CNTF binding and affinity cross‐linking studies were consistent with tripartite receptor activation as a mediator of the observed biological effects.
A Protease Inhibitor of the Serpin Family Is a Major Protein in Carp Perimeningeal Fluid: II. cDNA Cloning, Sequence Analysis, and Escherichia coli Expression
Authors: Huang Chang‐Jen , Lee Ming‐Shyue , Huang Fore‐Lien , Chang Geen‐Dong
Published: July 2010

Abstract: A cDNA clone, pCP9, has been isolated from a common carp liver cDNA library by immunoscreening with polyclonal antiserum raised against purified bighead carp α1‐antitrypsin. This clone is 1,396 bp in length and has an open reading frame encoding a protein of 410 amino acid residues. The deduced amino acid sequence shows moderate homology to human α1‐antitrypsin (38%), guinea pig contrapsin (35%), human α1‐antichymotrypsin (34%), and human proteinase C inhibitor (31%), all members of the serine protease inhibitor (serpin) family. To confirm further that the cDNA clone was derived from the authentic carp α1‐antitrypsin gene, the presumptive mature protein of pCP9 was expressed in Escherichia coli. The molecular mass of the recombinant protein matched that predicted from the nucleotide sequence. This recombinant protein, which was recognized by antiserum against native α1‐antitrypsin, was capable of formation of serpin‐enzyme complexes with trypsin, chymotrypsin, and elastase. Therefore, we conclude that the protein encoded by the pCP9 clone is indeed carp α1‐antitrypsin. Expression of α1‐antitrypsin in brain was confirmed by reverse transcription and polymerase chain reaction performed on mRNA derived from both common carp and bighead carp brain.
Lactate Metabolism and Its Effects on Glucose Metabolism in an Excised Neural Tissue
Authors: Larrabee Martin G.
Published: July 2010

Abstract: Chains of lumbar sympathetic ganglia, excised from 15‐day‐old chicken embryos, were incubated for 4 h at 36°C in a bicarbonate‐buffered physiological salt solution containing 5.5 mM glucose and equilibrated with 5% CO2–95% O2. [U‐14C]Glucose and [U‐14C]lactate were used as tracers to measure the products of glucose and lactate metabolism, respectively, including CO2, lactate, and constituents of the tissue. When 5 mM lactate was added to bathing solution containing 5.5 mM glucose, lactate carbon displaced 50–70% of the glucose carbon otherwise used for CO2 production and provided about three times as much carbon for CO2 as did glucose. The lactate addition increased the total carbon incorporated into CO2 and into constituents of the tissue above those observed with glucose alone and also increased the lactate released to the bathing solution from [U‐14C]‐glucose. The latter increase was evidently due to an interference with reuptake of the lactate released from the ganglion cells, not to an increase in the cellular release itself. When the volume of bathing solution was increased 10‐fold relative to that of the tissue, the average output of CO2 from [U‐14C]glucose during a 4‐h incubation was decreased by 50% when 5 mM lactate was present but was not affected significantly in the absence of added lactate. It is concluded that the effect of changing volume in the presence of lactate was due to the effects of lactate on glucose metabolism described above and resulted from a lower average lactate concentration in the smaller volume than in the larger one, due to metabolic depletion of the added lactate. Consumable substrates other than lactate, such as glutamine and certain amino acids, also affected glucose metabolism.
Protein Phosphatase‐1 Regulates Outward K+ Currents in Sensory Neurons of Aplysia californica
Authors: Endo Shogo , Critz Stuart D. , Byrne John H. , Shenolikar Shirish
Published: July 2010

Abstract: The peptide neurotransmitter Phe‐Met‐Arg‐PheNH2 (FMRFamide) increases outward K+ currents and promotes dephosphorylation of many phosphoproteins in Aplysia sensory neurons. We examined FMRFamide‐induced current responses in sensory neurons injected with thiophosphorylated protein phosphate inhibitor‐1 and inhibitor‐2 (I‐1 and I‐2), two structurally different vertebrate protein phosphatase‐1 (PP1) inhibitors to define a role for PP1 in the physiological actions of FMRFamide. Thiophosphorylated I‐1 and I‐2 both reduced the amplitude of outward currents elicited by FMRFamide by 50–60% and were as effective as microcystin‐LR, which inhibited both PP1 and protein phosphatase‐2A in Aplysia neuronal extracts. These data suggested that of the two major neuronal protein serine/threonine phosphatases, FMRFamide utilized primarily PP1 to open serotonin‐sensitive K+ (S‐K+) channels. Earlier studies showed that a membrane‐associated phosphatase regulated S‐K+ channels in cell‐free patches from sensory neurons. Utilizing its unique substrate specificity and inhibitor sensitivity, we have characterized PP1 as the principal protein phosphatase associated with neuronal plasma membranes. Two protein phosphatase activities (apparent Mr values of 170,000 and 38,000) extracted from crude membrane preparations from the Aplysia nervous system were shown to be isoforms of PP1. These biochemical and physiological studies suggest that PP1 is preferentially associated with neuronal membranes and that its activity may be required for the induction of outward K+ currents in the Aplysia sensory neurons by FMRFamide.
Protein Kinase FA/Glycogen Synthase Kinase 3α Predominantly Phosphorylates the In Vivo Sites of Ser502, Ser506, Ser603, and Ser666 in Neurofilament
Authors: Yang Shiaw‐Der , Huang Jun‐Jae , Huang Tze‐Jen
Published: July 2010

Abstract: In this report, the phosphorylation sites of neurofilament protein of medium molecular mass (NF‐M) by protein kinase FA/glycogen synthase kinase 3α (kinase FA/GSK‐3α) were determined by two‐dimensional electrophoresis/TLC, phosphoamino acid analysis, HPLC, Edman degradation, and peptide sequencing. Kinase FA/GSK‐3α phosphorylates NF‐M predominantly on serine, residue. Three major tryptic phosphopeptide peaks were resolved by C18 reverse‐phase HPLC. Edman degradation and peptide sequence analysis revealed that AKS(p)PVSK is the phosphorylation site sequence for the first major peak. When mapping with the amino acid sequence of neurofilament, we finally demonstrate Ser603‐Pro, one of the in vivo sites in NF‐M, as the major site phosphorylated by kinase FA/GSK‐3α. By using the same approach, we also identified the in vivo sites of Ser502‐Pro, Ser506‐Pro, and Ser666‐Pro as the other three major sites in NF‐M phosphorylated by kinase FA/GSK‐3α. Taken together, the results provide initial evidence that kinase FA/GSK‐3α may represent a physiologically relevant protein kinase involved in the in vivo phosphorylation of NF‐M. Because Ser502, Ser506, Ser603, and Ser666 are all flanked by a carboxyl‐terminal proline residue, the results provide further evidence that FA/GSK‐3α may represent a proline‐directed protein kinase involved in the structure‐function regulation of the neuronal cytoskeletal system.
Intracerebral Microdialysis: Electrophysiological Evidence of a Critical Pitfall
Authors: Obrenovitch Tihomir P. , Zilkha Elias , Urenjak Jutta
Published: July 2010

Abstract: Using microdialysis probes incorporating an electrode for the recording of extracellular field potentials, we have found that microdialysis markedly inhibited the propagation of spreading depression. This effect was independent of the microdialysis flow rate and did not result from tissue injury following probe implantation. Increasing the K+ concentration in the perfused artificial CSF dose‐dependently restored the propagation of spreading depression and revealed a large, synchronous transient increase in extracellular glutamate. These findings clearly illustrate that microdialysis can influence the experimental or pathological conditions under study, by buffering transient changes in the extracellular fluid composition. Epileptic seizures and ischaemia are two important conditions that may be prone to such a detrimental interaction.
Striatal Met‐Enkephalin and Substance P Levels Are Decreased in Mice Infected with the LP‐BM5 Murine Leukemia Virus
Authors: Ha Jeoung‐Hee , Sei Yoshitatsu , Basile Anthony S.
Published: July 2010

Abstract: Mice infected with the LP‐BM5 murine leukemia virus mixture develop severe immunosuppression and an encephalopathy characterized by spatial learning deficits. Twelve weeks after infection of C57BL/6J mice with LP‐BM5, significant (50–60%) reductions in Met‐enkephalin and substance P levels were observed in the striatum, whereas somatostatin levels were unchanged. In addition, a 39% decrease in hypothalamic substance P concentrations was observed, with no alteration in Met‐enkephalin levels. The apparent selectivity of the decrease in neuropeptide concentrations indicates that a functional alteration of the primary striatal efferent neurons occurs in this infection, which may contribute to the impairment of spatial learning observed in these mice. Moreover, this decrease in striatal neuropeptide levels is similar to the neuropathological changes in basal ganglia observed in HIV‐infected individuals and is consistent with previous studies suggesting that the LP‐BM5‐infected mouse may serve as a useful model of AIDS dementia.
Anticholinesterases: Medical Applications of Neurochemical Principles
Authors: Millard Charles B. , Broomfield Clarence A.
Published: July 2010

Abstract: Cholinesterases form a family of serine esterases that arise in animals from at least two distinct genes. Multiple forms of these enzymes can be precisely localized and regulated by alternative mRNA splicing and by co‐ or posttranslational modifications. The high catalytic efficiency of the cholinesterases is quelled by certain very selective reversible and irreversible inhibitors. Owing largely to the important role of acetylcholine hydrolysis in neurotransmission, cholinesterase and its inhibitors have been studied extensively in vivo. In parallel, there has emerged an equally impressive enzyme chemistry literature. Cholinesterase inhibitors are used widely as pesticides; in this regard the compounds are beneficial with concomitant health risk. Poisoning by such compounds can result in an acute but usually manageable medical crisis and may damage the CNS and the PNS, as well as cardiac and skeletal muscle tissue. Some inhibitors have been useful for the treatment of glaucoma and myasthenia gravis, and others are in clinical trials as therapy for Alzheimer's dementia. Concurrently, the most potent inhibitors have been developed as highly toxic chemical warfare agents. We review treatments and sequelae of exposure to selected anticholinesterases, especially organophosphorus compounds and carbamates, as they relate to recent progress in enzyme chemistry.
Opposite Effect of Protein Synthesis Inhibitors on Potassium Deficiency‐Induced Apoptotic Cell Death in Immature and Mature Neuronal Cultures
Authors: Kharlamov Elena , Cagnoli Cinzia M. , Atabay Cagla , Ikonomović Snežana , Grayson Dennis R. , Manev Hari
Published: July 2010

Abstract: Typically, primary cultures of rat cerebellar granule neurons are grown in the presence of 25 mM KCl and are considered to mature by ∼7 days in vitro. Potassium deficiency was created by growing the neurons from days 1 to 4 in the presence of 12.5 mM KCl (immature cultures) or by switching the mature neurons grown with 25 mM KCl to 12.5 mM KCl. In both conditions we observed neuronal death that bears the signs of apoptosis, i.e., DNA fragmentation determined qualitatively by agarose gel electrophoresis of DNA and quantitatively by in situ terminal deoxynucleotidyl transferase assay. The protein synthesis inhibitors cycloheximide and anisomycin provided neuroprotection in the mature cultures but potentiated the toxic effect of KCl deprivation in the immature neurons. The results suggest that a prudent use of protein synthesis inhibitors is critical in experiments with primary neuronal cultures.
Induction of Heme Oxygenase‐1 mRNA and Protein in Neocortex and Cerebral Vessels in Alzheimer's Disease
Authors: Premkumar Daniel R. D. , Smith Mark A. , Richey Peggy L. , Petersen Robert B. , Castellani Rudy , Kutty R. Krishnan , Wiggert Barbara , Perry George , Kalaria Rajesh N.
Published: July 2010

Abstract: Previous studies demonstrated the specific association of heme oxygenase (HO)‐1 protein to the neurofibrillary pathology of Alzheimer's disease (AD). In this study, we used reverse transcription‐polymerase chain reaction methods to show the increased expression of HO‐1 but not HO‐2 mRNA transcripts in cerebral cortex and cerebral vessels from subjects with AD compared with age‐matched non‐AD controls. Neither the HO‐1 nor the HO‐2 mRNA level was altered in the cerebellum, a brain region usually spared from the pathological alterations of AD. There was no clear evidence that the expression of HO‐1 in these tissues was related to postmortem interval, cause of death, or the age of the subjects studied. Using immunoblotting methods, we further showed that HO‐1 protein content was increased in neocortical and vascular samples from AD subjects compared with controls. Our findings suggest the specific induction of HO‐1 mRNA and protein in the cerebral cortex and cerebral vessels but not HO‐2 mRNA or protein in association with the pathological lesions of the disease.
Cortical Regulation of Subcortical Dopamine Release: Mediation via the Ventral Tegmental Area
Authors: Taber Matthew T. , Das Sheela , Fibiger Hans C.
Published: July 2010

Abstract: In vivo microdialysis was used to determine the extent to which ionotropic glutamate receptors in the ventral tegmental area (VTA) regulate dopamine release in the nucleus accumbens. Coapplication of 2‐amino‐5‐phosphonopentanoic acid (AP5; 200 µM) and 6‐cyano‐7‐nitroquinoxaline‐2,3‐dione (CNQX; 50 µM) to the VTA via reverse dialysis decreased extracellular concentrations of dopamine in the nucleus accumbens by ∼30%. In accordance with previous results, electrical stimulation of the prefrontal cortex increased dopamine release by 60%. Application of AP5 and CNQX to the VTA during cortical stimulation blocked the effect of stimulation on dopamine release. These results indicate that ionotropic glutamate receptors in the VTA are critically involved in basal and evoked dopamine release in the nucleus accumbens and suggest that a glutamatergic projection from the prefrontal cortex regulates the activity of dopaminergic neurons in the VTA.
Inhibition of Bradykinin‐Induced Cytosolic Ca2+ Elevation by Muscarinic Stimulation Without Attenuation of Inositol 1,4,5‐Trisphosphate Production in Human Neuroblastoma SK‐N‐BE(2)C Cells
Authors: Suh Byung‐Chang , Kim Kyong‐Tai
Published: July 2010

Abstract: Cross talk between two phospholipase C (PLC)‐linked receptor signalings was investigated in SK‐N‐BE(2)C human neuroblastoma cells. Sequential stimulation with two agonists at 5‐min intervals was performed to examine the interaction between muscarinic and bradykinin (BK) receptors. Pretreatment of cells with a maximal effective concentration (5 µM) of BK did not affect the subsequent carbachol (CCh)‐induced [Ca2+]i rise, but CCh (1 mM) pretreatment completely abolished the BK‐induced [Ca2+]i rise without inhibition of BK‐induced inositol 1,4,5‐trisphosphate (IP3) generation. Thapsigargin (1 µM) pretreatment abolished the subsequent BK‐ and CCh‐induced [Ca2+]i rise, though it did not affect agonist‐induced IP3 generation. However, the addition of atropine at plateau phases of CCh‐induced [Ca2+]i rise and IP3 production caused a rapid decline to the basal levels and then restored the [Ca2+]i rise by BK. Treatment of cells with both CCh and BK at the same time showed additive effects in IP3 production. However, the [Ca2+]i rise induced by both agonists in the presence or absence of extracellular Ca2+ was the same as the responses triggered by CCh alone. The results suggest that each receptor or receptor‐linked PLC activity is not influenced by pretreatment with the other agonist but IP3‐sensitive Ca2+ stores are shared by signal pathways from both receptors.
Hypoxia Increases the Susceptibility to Oxidant Stress and the Permeability of the Blood‐Brain Barrier Endothelial Cell Monolayer
Authors: Plateel Monique , Dehouck Marie‐Pierre , Torpier Gérard , Cecchelli Roméo , Teissier Elisabeth
Published: July 2010

Abstract: Using a cell culture model of the blood‐brain barrier (BBB), we investigated the brain capillary endothelial cell (EC) response to hypoxia. The activities of antioxidant enzymes such as glutathione peroxidase, glutathione reductase, catalase, and superoxide dismutase and the GSH level of brain capillary ECs alone or in coculture with astrocytes, as well as those of pericytes, were compared with those obtained with freshly isolated microvessels. These results demonstrated that brain capillary ECs cocultured with astrocytes and used in the presence of a coculture‐conditioned medium provided a relevant in vitro model for studying the effect of hypoxia‐reoxygenation at the BBB level. The effect of hypoxia on antioxidant enzymes, GSH, and ATP levels was studied, as well as the modification of the permeability to small weight molecules. A decrease in all enzymes and the GSH level could explain an increase in the susceptibility of the brain capillary ECs to further oxidant injury. Second, profound rearrangements of F‐actin filaments of the ECs and a decrease in the ATP level could be associated with an increase in the permeability of the monolayer. Furthermore, an apoptotic process was detected by in situ end labeling of DNA. These results indicate that hypoxia distorts the function of ECs and that these cells in culture provide a valuable tool for exploring mechanisms after hypoxia‐reoxygenation.