bluuebunny/crossref_metadata_2025 huggingface dataset:
Proton Stereotactic Radiotherapy for Persistent Adrenocorticotropin-Producing Adenomas
Authors: Petit Joshua H. , Biller Beverly M. K. , Yock Torunn I. , Swearingen Brooke , Coen John J. , Chapman Paul , Ancukiewicz Marek , Bussiere Marc , Klibanski Anne , Loeffler Jay S.
Published: November 2007

Context: Radiation therapy is a potentially curative treatment for corticotroph adenomas refractory to surgery. Protons have an advantage over photons (x-rays) by depositing energy at the target with no exit dose, providing a lower dose to adjacent normal tissues. Until recently, proton stereotactic radiotherapy (PSR) was available at only two U.S. centers; use will increase as proton facilities are under development.

Objective: Our objective was to evaluate the efficacy and safety of PSR for persistent Cushing’s disease (CD) and Nelson’s syndrome (NS).

Design: This was a retrospective review of 38 patients (33 with CD and five with NS) treated between 1992 and 2005.

Participants: All patients had transsphenoidal surgery without biochemical cure. Four had previous irradiation with photons. The patients with NS underwent bilateral adrenalectomy 29–228 months (median 40) before PSR.

Intervention: Single-fraction PSR was delivered at a median dose of 20 Cobalt Gray Equivalents (range 15–20) on 1 treatment day.

Main Outcome Measures: Complete response (CR) was defined as sustained (≥3 months) normalization of urinary free cortisol off medical therapy. CR in NS was based on normalization of plasma corticotropin.

Results: At a median follow-up of 62 months (range 20–136), CR was achieved in five patients (100%) with NS and 17 (52%) patients with CD. Among all patients with CR, median time to CR was 18 months (range 5–49). No secondary tumors were noted on follow-up magnetic resonance imaging scans, and there was no clinical evidence of optic nerve damage, seizure, or brain injury. There were 17 patients (52%) who developed new pituitary deficits.

Conclusions: PSR is effective for patients with persistent corticotroph adenomas with low morbidity after a median follow-up of 62 months; longer follow-up is warranted for late radiation-related sequelae.
Phosphorylation of WAVE2 by MAP kinases regulates persistent cell migration and polarity
Authors: Danson Christopher M. , Pocha Shirin M. , Bloomberg Graham B. , Cory Giles O.
Published: November 2007

The WAVE family of proteins has long been implicated in the stimulus-dependent generation of lamellipodia at the leading edge of migrating cells, with WAVE2 in particular implicated in the formation of peripheral ruffles and chemotactic migration. However, the lack of direct visualisation of cell migration in WAVE2 mutants or knockdowns has made defining the mechanisms of WAVE2 regulation during cell migration difficult. We have characterised three MAP kinase phosphorylation sites within WAVE2 and analysed fibroblast behaviour in a scratch-wound model following introduction of transgenes encoding phospho-defective WAVE2. The cells exhibited an increase in migration speed, a decrease in the persistence of migration, and disruption of polarisation of the Golgi apparatus. All these effects could be mimicked by acute knockdown of endogenous WAVE2 expression with RNAi, indicating that phosphorylation of WAVE2 by MAP kinases regulates cell polarity during migration.
New insights into PTEN
Authors: Tamguney Tanja , Stokoe David
Published: November 2007

The functions ascribed to PTEN have become more diverse since its discovery as a putative phosphatase mutated in many human tumors. Although it can dephosphorylate lipids and proteins, it also has functions independent of phosphatase activity in normal and pathological states. In addition, control of PTEN function is very complex. It is positively and negatively regulated at the transcriptional level, as well as post-translationally by phosphorylation, ubiquitylation, oxidation and acetylation. Although most of its tumor suppressor activity is likely to be caused by lipid dephosphorylation at the plasma membrane, PTEN also resides in the cytoplasm and nucleus, and its subcellular distribution is under strict control. Deregulation of PTEN function is implicated in other human diseases in addition to cancer, including diabetes and autism.
Biogenesis of yeast dicarboxylate carrier: the carrier signature facilitates translocation across the mitochondrial outer membrane
Authors: Zara Vincenzo , Ferramosca Alessandra , Capobianco Loredana , Baltz Katrin M. , Randel Olga , Rassow Joachim , Palmieri Ferdinando , Papatheodorou Panagiotis
Published: November 2007

A family of related carrier proteins mediates the exchange of metabolites across the mitochondrial inner membrane. The carrier signature Px[D/E]xx[K/R] is a highly conserved sequence motif in all members of this family. To determine its function in the biogenesis of carrier proteins, we used the dicarboxylate carrier (DIC) of yeast as a model protein. We found that the carrier signature was dispensable in binding of the newly synthesized protein to the import receptor Tom70, but that it was specifically required for efficient translocation across the mitochondrial outer membrane. To determine the relevance of individual amino acid residues of the carrier signature in the transport activity of the protein, we exchanged defined residues with alanine and reconstituted the mutant proteins in vitro. Substitution of the carrier signature in helix H1 reduced the transport activity for [33P]-phosphate by approximately 90% and an additional substitution of the carrier signature in helix H5 blocked the transport activity completely. We conclude that the carrier signature of the dicarboxylate carrier is involved both in the biogenesis and in the transport activity of the functional protein.
Autophagy, amyloidogenesis and Alzheimer disease
Authors: Nixon Ralph A.
Published: November 2007

Autophagy is the sole pathway for organelle turnover in cells and is a vital pathway for degrading normal and aggregated proteins, particularly under stress or injury conditions. Recent evidence has shown that the amyloid β peptide is generated from amyloid β precursor protein (APP) during autophagic turnover of APP-rich organelles supplied by both autophagy and endocytosis. Aβ generated during normal autophagy is subsequently degraded by lysosomes. Within neurons, autophagosomes and endosomes actively form in synapses and along neuritic processes but efficient clearance of these compartments requires their retrograde transport towards the neuronal cell body, where lysosomes are most concentrated. In Alzheimer disease, the maturation of autophagolysosomes and their retrograde transport are impeded, which leads to a massive accumulation of `autophagy intermediates' (autophagic vacuoles) within large swellings along dystrophic and degenerating neurites. The combination of increased autophagy induction and defective clearance of Aβ-generating autophagic vacuoles creates conditions favorable for Aβ accumulation in Alzheimer disease.
Isobutene Trimerization over FeCl3-modified HY Zeolites: Effect of Lewis Acid Sites
Authors: Yoon Ji Woong , Jhung Sung Hwa , Choo Dae Hyun , Lee Seung Jun , Chang Jong-San
Published: November 2007

Oligomerization of isobutene has been investigated using FeCl3-modified HY zeolite catalysts in order to produce triisobutenes or remove/separate isobutene from C4 streams. Stable isobutene conversion and high selectivity for trimers are attained over the modified zeolite with high concentration of Lewis acid sites, suggesting that a potential trimerization catalyst can be obtained easily by loading a Lewis acid into an acidic zeolite catalyst.
Cost Analytic Model to Determine the Least Costly Inpatient Erythropoiesis Stimulating Therapy Regimen
Authors: Sikand Harminder , Decter Adam , Greco Tina , Watson Sue H , Kang Yoon Jun , Mody Samir H , Piech Catherine Tak , Duh Mei Sheng , Naeem Ayesha
Published: November 2007

Background:

Unlike in outpatient settings, the comparative costs of epoetin alfa (EPO) and darbepoetin alfa (DARB) have not been evaluated broadly from the inpatient hospital perspective.

Objective:

To develop a cost analytic model comparing hospital inpatient costs for erythropoiesis stimulating therapies within the nephrology and oncology settings.

Methods:

A cost analytic model incorporating erythropoietic drug, pharmacy, and nursing costs was developed from the inpatient hospital perspective to evaluate comparative costs of EPO and DARB. Erythropoietic drug costs were calculated using unit wholesale acquisition cost multiplied by the number of units or micrograms while comparing the following dosing regimens: EPO 3 times weekly, EPO once weekly, and DARB once weekly. Pharmacy costs included dispensing and delivery costs, while nursing costs incorporated administration time costs; all were calculated by estimated fractional hours per activity multiplied by hourly wages. The total frequency of erythropoiesis stimulating therapy administrations was determined based on the average hospital length of stay. The first erythropoiesis stimulating therapy dose was assumed to occur on day 3 of hospitalization. For total inpatient costs, a weighted average was calculated across disease states. One-way sensitivity analyses were conducted by varying length of stay, day of initial erythropoiesis stimulating therapy dose, pharmacy and nursing costs, and once-weekly DARB dose.

Results:

EPO 3 times weekly was the least costly regimen across all disease states evaluated. Threshold analysis indicated that the cost of once-weekly DARB regimens would have to be reduced by 37% to equal the cost of EPO 3 times weekly for an average length of stay. Sensitivity analyses did not considerably affect the results.

Conclusions:

EPO 3 times weekly was found to be the least costly erythropoiesis stimulating therapy regimen for nephrology and oncology inpatients for the average length of stay as well as most other lengths of stay considered. Once-weekly EPO was the least costly erythropoiesis stimulating therapy regimen for several other lengths of stay, while once-weekly DARB was never found to be the least costly regimen.
Acetylation of aromatics over acid zeolites: Seeking a viable alternative to Friedel-Crafts catalysts
Authors: Guidotti Matteo , Coustard Jean-Marie , Magnoux Patrick , Guisnet Michel
Published: November 2007

Three acid zeolites (H-BEA, H-FAU, and H-MWW) were used as catalysts for acetylation in batch reactors with acetic anhydride of five aromatic compounds (benzenic and naphthalenic derivatives). The substrate reactivity is mainly governed by electronic factors (the nature of the substituents and degree of ring activation), but steric effects also play a relevant role when the reaction takes place in a narrow micropore system. In general, H-FAU was the most active catalyst, whereas with H-BEA remarkable steric constraints were observed. H-MWW showed good stability toward deactivation and an interesting activity of the sites located on the external surface.
Heteropolyacids as effective catalysts to obtain zero sulfur diesel
Authors: de Angelis Alberto , Pollesel Paolo , Molinari Daniele , O'Neal Parker Wallace , Frattini Alessandra , Cavani Fabrizio , Martins Susie , Perego Carlo
Published: November 2007

This paper deals with the catalytic properties of different supported heteropolyacids (HPAs), both molybdenum- and tungsten-based, in the oxidative desulfurization process of diesel. We are jointly developing a new oxidative desulfurization process, aimed at reducing the sulfur content in diesel to less than 10 ppm (parts per million) using in situ produced peroxides. In this new process, high-molecular-weight organosulfur compounds, such as 4,6-dimethyl-dibenzothiophene (DMDBT), difficult to be eliminated by conventional hydrodesulfurization, are oxidized to the corresponding sulfones and subsequently removed by adsorption. Molybdenum-based HPAs, with Keggin structure, proved to be the most active and selective catalysts for oxidizing DMDBT with on-stream lifetimes exceeding 1500 h time on stream (t.o.s.).
Green photochemistry: Production of fine chemicals with sunlight
Authors: Oelgemöller Michael , Jung Christian , Mattay Jochen
Published: November 2007

Three photochemical reactions were investigated under solar irradiation conditions with moderately concentrated sunlight: the photoacylation of naphthoquinone with butyraldehyde and the dye-sensitized photooxygenations of citronellol and 1,5-dihydroxynaphthalene, respectively. All reactions were easily performed on multigram-to-kilogram scales using cheap and commercially available starting materials, and yielded important key intermediates for industrial applications.
Novel sensor devices and monitoring strategies for green and sustainable chemistry processes
Authors: Brett Christopher M. A.
Published: November 2007

The principles of green chemistry include a statement as to the necessity for real-time analysis for prevention of pollution. Methodologies need to be developed for real-time, in-process monitoring and control prior to the formation of hazardous substances. These should be carried out by (chemical) sensors. Monitoring also allows optimizing the efficient use of reagents and permits determination of the composition of waste and effluents. In this paper, new monitoring strategies are surveyed and some of the recent advances which have been achieved with respect to novel devices in terms of miniaturization and reliability are indicated. Emphasis is given to continuous and online flow and injection methodologies and the requirements for successful sensors. Particular attention is given to the future potential of electrochemical flow and batch injection sensors which can often be used without external sample pretreatment. Electrochemical sensors using carbon film-based electrodes, including their application in room-temperature ionic liquids (RTILs) for which electrochemical methodologies are directly suited are also described.
Electrolysis for the benign conversion of renewable feedstocks
Authors: Schäfer Hans J. , Harenbrock Michael , Klocke Elisabeth , Plate Mark , Weiper-Idelmann Andreas
Published: November 2007

A large variety of C,C-bond forming reactions and functional group interconversions can be achieved by electron transfer. For the conversion of renewable feedstocks, electrolysis has been applied to coupling of radicals generated by anodic decarboxylation of fatty acids and carboxylic acids of carbohydrates. Furthermore, a derivative of L-gulonic acid is converted nearly quantitatively into L-xylonolacton. Trimethyl aconitate from trimethyl citronate is dimerized stereoselectively at the cathode in 72 % yield to a cyclic hexamethyl ester by an inter- and intramolecular Michael addition. Two acetoxy groups are added anodically to methyl conjuenate (obtained from methyl linoleate) to form methyl (E)-9,12-diacetoxy-10-octenoate and methyl (E)-10,13-diacetoxy-11-octenoate in 85 % yield. The primary hydroxy groups in mono- and disaccharides can be oxidized to carboxylic acid groups in good yield and high selectivity by anodic oxidation with 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) as mediator. The results demonstrate that electrolysis is in good accordance with many of the 12 principles of green chemistry.
Catalysis of nanosized Pd metal catalyst deposited on Ti-containing zeolite by a photo-assisted deposition (PAD) method
Authors: Yamashita Hiromi , Miura Yuki , Mori Kohsuke , Shironita Sayoko , Masui Yosuke , Mimura Naoki , Ohmichi Tetsutaro , Sakata Takao , Mori Hirotaro
Published: November 2007

Using a photo-assisted deposition (PAD) method, nanosized Pd metal can be highly dispersed on Ti-containing silicalite zeolite (TS-1) under UV-light irradiation (PAD-Pd/TS-1). The nanosized Pd metal was deposited directly on the photo-excited tetrahedrally coordinated titanium oxide species (tetra-Ti-oxide) of TS-1 zeolite. Under the flow of H2 and O2 in water solvent, the efficient formation of H2O2 could be observed by the PAD-Pd/TS-1 catalyst under mild reaction conditions (ambient temperature and atmospheric pressure). Furthermore, the presence of phenol in this reaction system led to the formation of the products from the partial oxidation of phenol with the formed H2O2.
Methionine Sulfoxide Reductase A and a Dietary SupplementS-Methyl-L-Cysteine Prevent Parkinson's-Like Symptoms
Authors: Wassef Ramez , Haenold Ronny , Hansel Alfred , Brot Nathan , Heinemann Stefan H. , Hoshi Toshinori
Published: November 2007

Parkinson's disease (PD), a common neurodegenerative disease, is caused by loss of dopaminergic neurons in the substantia nigra. Although the underlying cause of the neuronal loss is unknown, oxidative stress is thought to play a major role in the pathogenesis of PD. The amino acid methionine is readily oxidized to methionine sulfoxide, and its reduction is catalyzed by a family of enzymes called methionine sulfoxide reductases (MSRs). The reversible oxidation-reduction cycle of methionine involving MSRs has been postulated to act as a catalytic antioxidant system protecting cells from oxidative damage. Here, we show that one member of the MSR family, MSRA, inhibits development of the locomotor and circadian rhythm defects caused by ectopic expression of human α-synuclein in theDrosophilanervous system. Furthermore, we demonstrate that one way to enhance the MSRA antioxidant system is dietary supplementation withS-methyl-L-cysteine (SMLC), found abundantly in garlic, cabbage, and turnips. SMLC, a substrate in the catalytic antioxidant system mediated by MSRA, prevents the α-synuclein-induced abnormalities. Therefore, interventions focusing on the enzymatic reduction of oxidized methionine catalyzed by MSRA represent a new prevention and therapeutic approach for PD and potentially for other neurodegenerative diseases involving oxidative stress.
Cyclin-Dependent Kinase 5 Is Required for Control of Neuroblast Migration in the Postnatal Subventricular Zone
Authors: Hirota Yuki , Ohshima Toshio , Kaneko Naoko , Ikeda Makiko , Iwasato Takuji , Kulkarni Ashok B. , Mikoshiba Katsuhiko , Okano Hideyuki , Sawamoto Kazunobu
Published: November 2007

At the lateral wall of the lateral ventricles in the adult rodent brain, neuroblasts form an extensive network of elongated cell aggregates called chains in the subventricular zone and migrate toward the olfactory bulb. The molecular mechanisms regulating this migration of neuroblasts are essentially unknown. Here, we report a novel role for cyclin-dependent kinase 5 (Cdk5), a neuronal protein kinase, in this process. Usingin vitroandin vivoconditional knock-out experiments, we found thatCdk5deletion impaired the chain formation, speed, directionality, and leading process extension of the neuroblasts in a cell-autonomous manner. These findings suggest that Cdk5 plays an important role in neuroblast migration in the postnatal subventricular zone.
Probing the Mechanism of Exocytosis at the Hair Cell Ribbon Synapse
Authors: Neef Andreas , Khimich Darina , Pirih Primoz , Riedel Dietmar , Wolf Fred , Moser Tobias
Published: November 2007

Hearing relies on faithful synaptic transmission at the ribbon synapse of cochlear inner hair cells (IHCs). Postsynaptic recordings from this synapse in prehearing animals had delivered strong indications for synchronized release of several vesicles. The underlying mechanism, however, remains unclear. Here, we used presynaptic membrane capacitance measurements to test whether IHCs release vesicles in a statistically independent or dependent (coordinated) manner. Exocytic changes of membrane capacitance (ΔCm) were repeatedly stimulated in IHCs of prehearing and hearing mice by short depolarizations to preferentially recruit the readily releasable pool of synaptic vesicles. A compound Poisson model was devised to describe hair cell exocytosis and to test the analysis. From the trial-to-trial fluctuations of the ΔCmwe were able to estimate the apparent size of the elementary fusion event (Capp) at the hair cell synapse to be 96–223 aF in immature and 55–149 aF in mature IHCs. We also approximated the single vesicle capacitance in IHCs by measurements of synaptic vesicle diameters in electron micrographs. The results (immature, 48 aF; mature, 45 aF) were lower than the respectiveCappestimates. This indicates that coordinated exocytosis of synaptic vesicles occurs at both immature and mature hair cell synapses. Approximately 35% of the release events in mature IHCs and ∼50% in immature IHCs were predicted to involve coordinated fusion, when assuming a geometric distribution of elementary sizes. In summary, our presynaptic measurements indicate coordinated exocytosis but argue for a lesser degree of coordination than suggested by postsynaptic recordings.
Stepping into the Third Dimension
Authors: Feng David , Marshburn David , Jen Dennis , Weinberg Richard J. , Taylor Russell M. , Burette Alain
Published: November 2007

Recent advances in optical-sectioning microscopy, along with novel fluorescent proteins and probes, give us the tools to image molecules and their interactions in space and time. Investigators using these tools routinely collect multichannel three-dimensional (3D) images and time series, but analyzing such complex datasets requires sophisticated visualization techniques. We here provide an overview of the principles and practices of 3D visualization of multichannel microscopic data. We also describe ImageSurfer, a new software package for volume visualization and data analysis. ImageSurfer is freely available (www.imagesurfer.org) and provides powerful interactive tools to explore and analyze complex multichannel 3D datasets. Although ImageSurfer is designed with fluorescent microscopy in mind, it is also effective for other types of data, including 3D datasets acquired by functional magnetic resonance imaging and EM tomography.
Cortical Thickness in Congenital Amusia: When Less Is Better Than More
Authors: Hyde Krista L. , Lerch Jason P. , Zatorre Robert J. , Griffiths Timothy D. , Evans Alan C. , Peretz Isabelle
Published: November 2007

Congenital amusia (or tone deafness) is a lifelong disorder characterized by impairments in the perception and production of music. A previous voxel-based morphometry (VBM) study revealed that amusic individuals had reduced white matter in the right inferior frontal gyrus (IFG) relative to musically intact controls (Hyde et al., 2006). However, this VBM study also revealed associated increases in gray matter in the same right IFG region of amusics. The objective of the present study was to better understand this morphological brain anomaly by way of cortical thickness measures that provide a more specific measure of cortical morphology relative to VBM. We found that amusic subjects (n= 21) have thicker cortex in the right IFG and the right auditory cortex relative to musically intact controls (n= 26). These cortical thickness differences suggest the presence of cortical malformations in the amusic brain, such as abnormal neuronal migration, that may have compromised the normal development of a right frontotemporal pathway.
Diminishing Apoptosis by Deletion of Bax or Overexpression of Bcl-2 Does Not Protect against Infectious Prion ToxicityIn Vivo
Authors: Steele Andrew D. , King Oliver D. , Jackson Walker S. , Hetz Claudio A. , Borkowski Andrew W. , Thielen Peter , Wollmann Robert , Lindquist Susan
Published: November 2007

B-cell lymphoma protein 2 (Bcl-2) and Bcl-2-associated X protein (Bax), key antiapoptotic and proapoptotic proteins, respectively, have important roles in acute and chronic models of neurologic disease. Several studies have implicated Bax and Bcl-2 in mediating neurotoxicity in prion diseases. To determine whether diminishing apoptotic cell death is protective in an infectious prion disease model we inoculated mice that either were null for proapoptotic Bax or overexpressed antiapoptotic Bcl-2. Interestingly, genetic manipulation of apoptosis did not lessen the clinical severity of disease. Moreover, some disease parameters, such as behavioral alterations and death, occurred slightly earlier in mice that are null for Bax or overexpress Bcl-2. These results suggest that Bax and Bcl-2 mediated apoptotic pathways are not the major contributing factor to the clinical or pathological features of infectious prion disease.
Resonant or Not, Two Amplification Modes of Proprioceptive Inputs by Persistent Inward Currents in Spinal Motoneurons
Authors: Manuel Marin , Meunier Claude , Donnet Maud , Zytnicki Daniel
Published: November 2007

Why do motoneurons possess two persistent inward currents (PICs), a fast sodium current and a slow calcium current? To answer this question, we replaced the natural PICs with dynamic clamp-imposed artificial PICs at the soma of spinal motoneurons of anesthetized cats. We investigated how PICs with different kinetics (1–100 ms) amplify proprioceptive inputs. We showed that their action depends on the presence or absence of a resonance created by theIhcurrent. In resonant motoneurons, a fast PIC enhances the resonance and amplifies the dynamic component of Ia inputs elicited by ramp-and-hold muscle stretches. This facilitates the recruitment of these motoneurons, which likely innervate fast contracting motor units developing large forces, e.g., to restore balance or produce ballistic movements. In nonresonant motoneurons, in contrast, a fast PIC easily triggers plateau potentials, which leads to a dramatic amplification of the static component of Ia inputs. This likely facilitates the recruitment of these motoneurons, innervating mostly slowly contracting and fatigue-resistant motor units, during postural activities. Finally, a slow PIC may switch a resonant motoneuron to nonresonant by counterbalancingIh, thus changing the action of the fast PIC. A modeling study shows thatIhneeds to be located on the dendrites to create the resonance, and it predicts that dendritic PICs amplify synaptic input in the same manner as somatic PICs.
Modulation of Semaphorin3A Activity by p75 Neurotrophin Receptor Influences Peripheral Axon Patterning
Authors: Ben-Zvi Ayal , Ben-Gigi Liat , Klein Hagit , Behar Oded
Published: November 2007

The p75 neurotrophin receptor (p75NTR) interacts with multiple ligands and coreceptors. It is thought to mediate myelin growth inhibition as part of the Nogo receptor complex, in addition to its other roles. Paradoxically, however, peripheral axons of p75ExonIII−/−mutant embryos are severely stunted. This inhibition of axon growth may be a result of neurite elongation defects in p75NTRmutant neurons. Here, we show that p75ExonIII−/−DRG neurons are hypersensitive to the repellent molecule Semaphorin3A (Sema3A). NGF modulates Sema3A activity equally well in both the p75NTRmutant and wild-type neurons, indicating that the hypersensitivity of p75NTRmutant neurons is probably not related to their NGF receptor activity. Neuropilin1 and p75NTRpartially colocalize in DRG growth cones. After Sema3A stimulation, the degree of colocalization is dramatically increased, particularly in clusters associated with Sema3A receptor complex activation. Coimmunoprecipitation studies show that p75NTRinteracts directly with the Sema3A receptors Neuropilin1 and PlexinA4. When coexpressed with both Neuropilin1 and PlexinA4, p75NTRreduces the interaction between these two receptor components. Finally, p75NTR/Sema3A double-mutant embryos show growth similar to that observed in Sema3A-null mice. These data indicate that p75NTRis an important functional modulator of Sema3A activity and that, in the absence of p75NTR, oversensitivity to Sema3A leads to severe reduction in sensory innervation. Our results also suggest that while inhibition of p75NTRin CNS injury may enhance nerve regeneration resulting from the inhibition of myelin-associated protein, it may also inhibit nerve regeneration through its modulation of Sema3A.
Progressive Dendritic HCN Channelopathy during Epileptogenesis in the Rat Pilocarpine Model of Epilepsy
Authors: Jung Sangwook , Jones Terrance D. , Lugo Joaquin N. , Sheerin Aaron H. , Miller John W. , D'Ambrosio Raimondo , Anderson Anne E. , Poolos Nicholas P.
Published: November 2007

Ion channelopathy plays an important role in human epilepsy with a genetic cause and has been hypothesized to occur in epilepsy after acquired insults to the CNS as well. Acquired alterations of ion channel function occur after induction of status epilepticus (SE) in animal models of epilepsy, but it is unclear how they correlate with the onset of spontaneous seizures. We examined the properties of hyperpolarization-activated cation (HCN) channels in CA1 hippocampal pyramidal neurons in conjunction with video-EEG (VEEG) recordings to monitor the development of spontaneous seizures in the rat pilocarpine model of epilepsy. Our results showed that dendritic HCN channels were significantly downregulated at an acute time point 1 week postpilocarpine, with loss of channel expression and hyperpolarization of voltage-dependent activation. This downregulation progressively increased when epilepsy was established in the chronic period. Surprisingly, VEEG recordings during the acute period showed that a substantial fraction of animals were already experiencing recurrent seizures. Suppression of these seizures with phenobarbital reversed the change in the voltage dependence ofIh, the current produced by HCN channels, but did not affect the loss of HCN channel expression. These results suggest two mechanisms of HCN channel downregulation after SE, one dependent on and one independent of recurrent seizures. This early and progressive downregulation of dendritic HCN channel function increases neuronal excitability and may be associated with both the process of epileptogenesis and maintenance of the epileptic state.
Cdk5 Modulates Cocaine Reward, Motivation, and Striatal Neuron Excitability
Authors: Benavides David R. , Quinn Jennifer J. , Zhong Ping , Hawasli Ammar H. , DiLeone Ralph J. , Kansy Janice W. , Olausson Peter , Yan Zhen , Taylor Jane R. , Bibb James A.
Published: November 2007

Cyclin-dependent kinase 5 (Cdk5) regulates dopamine neurotransmission and has been suggested to serve as a homeostatic target of chronic psychostimulant exposure. To study the role of Cdk5 in the modulation of the cellular and behavioral effects of psychoactive drugs of abuse, we developed Cre/loxPconditional knock-out systems that allow temporal and spatial control of Cdk5 expression in the adult brain. Here, we report the generation of Cdk5 conditional knock-out (cKO) mice using the αCaMKII promoter-driven Cre transgenic line (CaMKII-Cre). In this model system, loss of Cdk5 in the adult forebrain increased the psychomotor-activating effects of cocaine. Additionally, these CaMKII-Cre Cdk5 cKO mice show enhanced incentive motivation for food as assessed by instrumental responding on a progressive ratio schedule of reinforcement. Behavioral changes were accompanied by increased excitability of medium spiny neurons in the nucleus accumbens (NAc) in Cdk5 cKO mice. To study NAc-specific effects of Cdk5, another model system was used in which recombinant adeno-associated viruses expressing Cre recombinase caused restricted loss of Cdk5 in NAc neurons. Targeted knock-out of Cdk5 in the NAc facilitated cocaine-induced locomotor sensitization and conditioned place preference for cocaine. These results suggest that Cdk5 acts as a negative regulator of neuronal excitability in the NAc and that Cdk5 may govern the behavioral effects of cocaine and motivation for reinforcement.
Characterization of the Kynurenine Pathway in Human Neurons
Authors: Guillemin Gilles J. , Cullen Karen M. , Lim Chai K. , Smythe George A. , Garner Brett , Kapoor Vimal , Takikawa Osamu , Brew Bruce J.
Published: November 2007

The kynurenine pathway is a major route ofl-tryptophan catabolism producing neuroactive metabolites implicated in neurodegeneration and immune tolerance. We characterized the kynurenine pathway in human neurons and the human SK-N-SH neuroblastoma cell line and found that the kynurenine pathway enzymes were variably expressed. Picolinic carboxylase was expressed only in primary and some adult neurons but not in SK-N-SH cells. Because of this difference, SK-N-SH cells were able to produce the excitotoxin quinolinic acid, whereas human neurons produced the neuroprotectant picolinic acid. The net result of kynurenine pathway induction in human neurons is therefore predicted to result in neuroprotection, immune regulation, and tumor inhibition, whereas in SK-N-SH cells, it may result in neurotoxicity, immune tolerance, and tumor promotion. This study represents the first comprehensive characterization of the kynurenine pathway in neurons and the first description of the involvement of the kynurenine pathway as a mechanism for controlling both tumor cell neurotoxicity and persistence.
Neuroprotective Effects of Synaptic Modulation in Huntington's Disease R6/2 Mice
Authors: Stack Edward C. , Dedeoglu Alpaslan , Smith Karen M. , Cormier Kerry , Kubilus James K. , Bogdanov Mikhail , Matson Wayne R. , Yang Lichuan , Jenkins Bruce G. , Luthi-Carter Ruth , Kowall Neil W. , Hersch Steven M. , Beal M. Flint , Ferrante Robert J.
Published: November 2007

Huntington's disease (HD) is an autosomal dominant inherited neurodegenerative disorder in which the neostriatum degenerates early and most severely, with involvement of other brain regions. There is significant evidence that excitotoxicity may play a role in striatal degeneration through altered afferent corticostriatal and nigrostriatal projections that may modulate synaptically released striatal glutamate. Glutamate is a central tenant in provoking excitotoxic cell death in striatal neurons already weakened by the collective molecular events occurring in HD. In addition, transcriptional suppression of trophic factors occurs in human and transgenic mouse models of HD, suggesting that a loss of trophic support might contribute to degeneration. Since anti-glutamate approaches have been effective in improving disease phenotype in HD mice, we examined whether deafferentation of the corticostriatal and nigrostriatal pathways may mitigate striatal stress and neurodegeneration. Both surgical and chemical lesions of the corticostriatal and nigrostriatal pathways, respectively, improved the behavioral, neuropathological, and biochemical phenotype in R6/2 transgenic mice and extended survival. Decortication ameliorated hindlimb clasping, striatal neuron atrophy, and huntingtin-positive aggregates, improvedN-acetyl aspartate/creatine levels, reduced oxidative stress, and significantly lowered striatal glutamate levels. In addition, 6-hydroxydopamine lesioned mice showed extended survival along with a significant reduction in striatal glutamate. These results suggest that synaptic stress is likely to contribute to neurodegeneration in HD, whereas transsynaptic trophic influences may not be as salient. Thus, modulation of synaptic influences continues to have therapeutic potential in HD.
A Preliminary Study on English and Welsh “Sacred Sites” and Home Dream Reports
Authors: Devereux Paul , Krippner Stanley , Tartz Robert , Fish Adam
Published: November 2007

This article discusses preliminary data on advancing what we know about “sacred sites” and their effects on dreaming. Thirty‐five volunteers spent between one and five nights in one of four unfamiliar outdoor sacred sites in England and Wales. Another volunteer awakened them following the observation of rapid eye movement and asked for dream recall. The same volunteers monitored their own dreams in familiar home surroundings, keeping dream diaries. Equal numbers of site dreams and home dream reports were obtained for each volunteer. The 204 dream reports had previously been subjected to inspection for bizarre and paranormal content, with no significant differences. This analysis used the Hall—Van de Castle Scale, and several differences were found, most notably more aggressive content in site dreams and more friendly content in home dreams. In addition, home dream reports contained more incidences of failure, striving, and success. A number of explanations were proposed for these differences, including expectancy, suggestion, the effect of unfamiliar surroundings, and possible anomalous properties of the sacred sites.
Facing Risk: Levinas, Ethnography, and Ethics
Authors: Benson Peter , O'neill Kevin Lewis
Published: November 2007

This article examines methodological and ethical issues of ethnographic research through the lens of Emmanuel Levinas's philosophy. Levinas is relevant to a critical analysis of ethnographic methods because his philosophy turns on the problematic relationship between self and other, among other important problems that define and guide contemporary anthropological research, including questions of responsibility, justice, and solidarity. This article utilizes Levinas's philosophy to outline a phenomenology of the “doing” of fieldwork, emphasizing the contingency of face‐to‐face encounters over controlled research design. This account provides a basis for going beyond the polarized opposition between objective and subjective ethnographic approaches. Levinas allows for an ethically informed ethnography premised upon an acknowledgement of risk and uncertainity over researcher control or reflexivity. Providing a handful of concrete examples, the article argues that critical self‐reflection about the fundamental face‐to‐face dimension of fieldwork is central to ethnography's ethical possibilities.
The Living and the Lost: War and Possession in Vietnam
Authors: Lan Gustafsson Mai
Published: November 2007

The war in Vietnam claimed the lives of five million of its citizens, many of whom died in ways thought to have turned them into malevolent spirits who prey on the living. These angry ghosts are held responsible for a host of physical ailments and other misfortunes suffered by survivors of the war and their descendants. Known in the anthropological literature as possession illness, the cross‐cultural treatment for such maladies is typically provided by practitioners like mediums and exorcists, who cure victims by interacting with noncorporeal entities. In Vietnam, such spirit healers were banned after the communist takeover of the North in 1945. This has posed a problem for the large numbers of Vietnamese who suffer from ghost‐induced sickness. This paper focuses on three victims of angry ghosts, presenting the common origin, context, and resolution of their suffering. In doing so, it provides an overview of Vietnamese beliefs about death and the after‐life, the ideal relationship between the living and the dead, and the connection between state politics and spirit practice.
Mad Thoughts on Mushrooms: Discourse and Power in the Study of Psychedelic Consciousness
Authors: Letcher Andy
Published: November 2007

This paper addresses the question of what happens to consciousness under the influence of psychedelic drugs—specifically of psilocybin, or “magic” mushrooms— and performs a Foucauldian discourse analysis upon the answers that have been variously proposed. Predominant societally legitimated answers (the pathological, psychological, and prohibition discourses) are those that, in Foucault's sense, are imposed from the outside as “scientific classifications,” that is, they are based upon observations of the effects of mushrooms on others. By contrast, a series of resistive discourses (the recreational, psychedelic, entheogenic, and animistic discourses) have been constructed in opposition, as a means of making sense of the subjective experience of taking mushrooms. When critiqued, only the animistic discourse— the belief that mushrooms occasion encounters with discarnate spirit entities, or animaphany—transgresses a fundamental societal boundary. In the West, to believe in the existence of spirits is to risk being labeled “mad,” and as such the phenomenon of mushroom‐induced animaphany goes largely ignored. It nevertheless remains a phenomenon in need of further scholarly research.
The Advent of a New Japanese Politics: Effects of the 1994 Revision of the Electoral Law
Authors: Kaihara Hiroshi
Published: November 2007

Faction-ridden Japanese politics seems to give way to a new politics. The 1994 revision of the electoral law generated an enormous change in the power relationship between faction leaders and the prime minister. Koizumi Jun'ichiro's strategy exemplified the potentiality of the new politics.
Japan-Taiwan Relations: Unofficial in Name Only
Authors: Sun Jing
Published: November 2007

As a result of normalization of Sino-Japanese relations in 1972, Japan cut off its diplomatic ties with the Republic of China (Taiwan). What followed was nearly two decades of diplomatic tepidity between Tokyo and Taipei. Since the 1990s, however, Japan and Taiwan have been rapidly approaching each other again. This commingling process, which has elevated their relations to an “unofficial-in-name-only” status, is the result of three mutually reinforcing factors: re-imagination of colonial ties, sharing of a democratic identity, and the permeating of popular culture.
Personalization of Mail Surveys for General Public and Populations with a Group Identity: Results from Nine Studies*
Authors: Dillman Don A. , Lesser Virginia , Mason Robert , Carlson John , Willits Fern , Robertson Rob , Burke Bryan
Published: November 2007

Abstract The effect of personalization on mail survey response rates was examined in nine studies that included 17 comparisons under several research conditions. A study of this variable across multiple experiments in five agricultural experiment stations was undertaken because of conflicting results from previous research and from concern that the effectiveness of personalization might have decreased over time. Results show that, while response to general public surveys appeared to increase modestly across all treatment groups, there was no positive effect for populations in which a group identity (e.g., Dear Oregon Gardner or Dear ATV Owner) is employed to address respondents in cover letters. Personalization appears to remain useful for improving response in surveys of the general public.
Redução de nitrato em plantas jovens de café cultivadas em diferentes níveis de luz e de nitrogênio
Authors: Carelli Maria Luiza Carvalho , Fahl Joel Irineu , Magalhães Antonio Celso
Published: November 2007

Foi estudado o efeito de níveis de luz e de nitrogênio na atividade da enzima redutase de nitrato e nos teores de nitrato e de açúcares nas folhas de plantas jovens de café (Coffea arabica L), assim como as possíveis relações entre a disponibilidade desses compostos e a atividade enzimática. Foram utilizadas plantas de dez meses de idade cultivadas em vasos contendo uma mistura de terra mais composto, e mantidas em condições ambientais em pleno sol e em 50% da luz solar. Metade das plantas de cada tratamento de luz foi suplementada semanalmente com nitrogênio. Os resultados mostraram que a atividade da redutase de nitrato, nos dois tratamentos de luz, foi maior nas plantas suplementadas com nitrogênio. Para um mesmo nível de nitrogênio, as plantas cultivadas em pleno sol apresentaram menor atividade da redutase de nitrato, maiores teores de nitrato e de açúcares e maiores taxas de transpiração, do que as cultivadas na sombra. Tais resultados indicam que a menor atividade da redutase de nitrato nas plantas cultivadas em pleno sol aparentemente não foi devida a limitações na disponibilidade de nitrato e de açúcares para fornecer a energia necessária para a redução de nitrato.
Melhoramento do trigo: XXIII. Avaliação de linhagens na região do vale do Paranapanema, em Capão Bonito e em Tietê, em 1984-88
Authors: Camargo Carlos Eduardo de Oliveira , Felício João Carlos , Ferreira Filho Antonio Wilson Penteado , Freitas José Guilherme de , Barros Benedito de Camargo , Castro Jairo Lopes de , Sabino José Carlos , Kanthack Ricardo Augusto dias
Published: November 2007

Compararam-se vinte e duas linhagens e três cultivares de trigo em seis ensaios, instalados na região do Vale do Paranapanema, em 1984-88, analisando-se os seguintes parâmetros: rendimento de grãos; altura das plantas; ciclo, em dias, da emergência ao florescimento; porcentagem de plantas acamadas; comprimento da espiga; número de grãos por espiga e por espigueta; número de espiguetas por espiga; peso de cem grãos; resistência à ferrugem-do-colmo e da-folha em condições de campo e de casa de vegetação; resistência ao oídio e às manchas foliares em condição de campo. Realizaram-se também mais dois ensaios: um em Tietê, em condição de boa fertilidade do solo, e outro em Capão Bonito, em solo ácido. Em laboratório, efetuaram-se estudos da tolerância ao alumínio em soluções nutritivas. Em condição de sequeiro, na região do Vale do Paranapanema e em solo ácido de Capão Bonito, sobressaiu, quanto à produção de grãos, a linhagem 19 (CNT-9 x BH-1146) = IAC-227, com ciclo e porte médio. Em Tietê, destacaram-se pela produtividade as linhagens de ciclo médio: 1 (Alondra-S-46 x IAC-5) = IAC-225, e 17 (Alondra-1 x IAC-5) = IAC-226, ambas de porte baixo, e 3 (Alondra-S-46 x C-3), de porte alto. A 21 (IAC-5 x Alondra-S-46) mostrou-se resistente às duas misturas de raças da ferrugem-do-colmo, à ferrugem-da-folha em condição de campo e às duas misturas de raças dessa ferrugem em condição de casa de vegetação, com resistência, em planta adulta, ao oídio, e com menor área foliar infectada pelos patógenos causadores de manchas foliares, constituindo fonte de resistência a essas doenças. As linhagens 6 (C-3 x Sonora-64) e 17 mostraram-se fontes genéticas do caráter espiga comprida; a 17, de maior número de espiguetas e de grãos por espiga; a 10 (Jupateco x IAC-13), de maior número de grãos por espigueta, e a 5 (Tobari-66 x BH-1146), de grãos mais pesados. As linhagens 7, 9, 13, 16, 17 e 19 e o 'BH-1146' exibiram tolerância a presença de 10 mg/litro de Al3+ na solução nutritiva.
O pessegueiro no sistema de pomar compacto: III. Épocas de poda drástica na diferenciação floral
Authors: Barbosa Wilson , Campo-Dall'Orto Fernando Antonio , Ojima Mário , Sampaio Vladimir Rodrigues
Published: November 2007

Pesquisou-se, na região de Jundiaí, SP (23°8'S), a influência das épocas de poda drástica na diferenciação floral dos pessegueiros Tropical' e 'Aurora-2', conduzidos em alta densidade de plantio (1.667 plantas por hectare). Realizaram-se tais podas em 30 de setembro, 30 de outubro e 30 de novembro de 1986. Coletaram-se as gemas para análise mensalmente, a partir do 30° dia da poda: constatou-se, através de cortes histológicos das gemas, que a poda drástica precoce, de 30 de setembro, não prejudicou a diferenciação floral dos pessegueiros, que se iniciou em fevereiro, a cerca de cinco meses da decepa; em abril, a maioria das gemas de flancos encontrava-se com as sépalas, as pétalas, os estames e o pistilo completamente formados. As demais épocas de poda interferiram no processo de diferenciação floral, reduzindo o número de botões florais e, conseqüentemente, a densidade florífera das plantas. Nos pessegueiros conduzidos com poda normal, a organogênese floral, processada no início do verão (dezembro-janeiro), persistiu até o outono (abril).
Herbicidas na nodulação e na atividade da nitrogenase em cultura de amendoim
Authors: Novo Maria do Sarmo S. Soares , Cruz Luciano Souza Paes , Portugal Edilberto Prince , Nagai Violeta , Ortolan Manoel Carlos Azevedo
Published: November 2007

Com o objetivo de estudar os efeitos de trifluralin, metolachlor e linufon, aplicados, respectivamente, em pré-plantio-incorporado, pré-emergência e em pós-emergência, sobre o peso de matéria seca e número de nódulos e sobre a atividade da nitrogenase, foi conduzido um experimento de campo, em cultura de amendoim (Arachis hypogaea cv. Tatu) plantada em rotação com cana-de-açúcar. Os resultados das avaliações feitas aos 30, 50 e 80 dias após a germinação mostraram não haver diferença entre tratamentos inoculados e não inoculados. Linuron foi o único herbicida prejudicial à nodulação, tendo afetado o número e o peso da matéria seca de nódulos, nas diferentes amostragens, e inibido a fixação do nitrogênio (estimada pela técnica da redução do acetileno). Não foi observado efeito prejudicial dos herbicidas metolachtor e trifluralin, na nodulação e na atividade da nitrogenase.