bluuebunny/crossref_metadata_2025 huggingface dataset:
Human CD4+CD25+ regulatory T cells selectively express tyrosine hydroxylase and contain endogenous catecholamines subserving an autocrine/paracrine inhibitory functional loop
Authors: Cosentino Marco , Fietta Anna Maria , Ferrari Marco , Rasini Emanuela , Bombelli Raffaella , Carcano Elena , Saporiti Federica , Meloni Federica , Marino Franca , Lecchini Sergio
Published: September 2006

CD4+CD25+ regulatory T lymphocytes (Tregs) are specialized T cells playing a key role in the control of immune homeostasis. Here, we show that human Tregs constitutively express tyrosine hydroxylase (TH, EC 1.14.16.2), the rate-limiting enzyme in the synthesis of catecholamines, and contain substantial amounts of dopamine, norepinephrine, and epinephrine, which are released upon treatment with reserpine. Catecholamine release results in reduced production of interleukin-10 and transforming growth factor-β by Tregs, and in down-regulation of Treg-dependent inhibition of effector T-lymphocyte (Teff) proliferation, which occurs without affecting the production of tumor necrosis factor-α or interferon-γ. Tregs and Teffs express on the cell membrane both D1-like and D2-like dopaminergic receptors to a similar extent (12%-29% of the cells). Catecholamine-dependent down-regulation of Tregs is, however, selectively reversed by pharmacological blockade of dopaminergic D1-like receptors, which in Tregs only (and not in Teffs) are also expressed at the level of mRNA and are functionally coupled to intracellular production of cAMP. These findings indicate that in human Tregs endogenous catecholamines subserve an autocrine/paracrine loop involving dopaminergic pathways and resulting in down-regulation of Treg function.
Incidence of CSF3R mutations in severe congenital neutropenia and relevance for leukemogenesis: results of a long-term survey
Authors: Germeshausen Manuela , Ballmaier Matthias , Welte Karl
Published: September 2006

Point mutations in the gene for the granulocyte colony-stimulating factor (G-CSF) receptor CSF3R have been implicated in the progression of severe congenital neutropenia (CN) to leukemia. In this study we present data on a total of 218 patients with chronic neutropenia, including 148 patients with CN (23/148 with secondary malignancies). We detected CSF3R nonsense mutations at 17 different nucleotide positions (thereof 10 new mutations) which lead to a loss of 1 to all 4 tyrosine residues in the intracellular domain of the receptor. Of 23 patients with CN with signs of malignant transformation, 18 (78%) were shown to harbor a CSF3R mutation, indicating that these mutations, although not a necessary condition, are highly predictive for malignant transformation even if detected in a low percentage of transcripts. In serial analyses of 50 patients with CSF3R mutations we were able to follow the clonal dynamics of mutated cells. We could demonstrate that even a highly clonal hematopoiesis did not inevitably show a rapid progression to leukemia. Our results strongly suggest that acquisition of a CSF3R mutation is an early event in leukemogenesis that has to be accompanied by cooperating molecular events, which remain to be defined.
Current concepts on the pathogenesis of the antiphospholipid syndrome
Authors: Giannakopoulos Bill , Passam Freda , Rahgozar Soheila , Krilis Steven A.
Published: September 2006

The antiphospholipid syndrome (APS) is an important cause of acquired thrombophilia. It is characterized by the core clinical manifestations of thrombosis, either venous or arterial, and in women it can also be associated with recurrent fetal loss. The detection of persistently elevated levels of antiphospholipid antibodies (aPL Abs) is a requisite laboratory feature for the diagnosis to be made. The dominant antigenic targets in APS are beta 2-glycoprotein I (β2-GPI) and prothrombin. There is an accumulating body of experimental evidence that suggests that specific subgroups of aPL Abs may directly contribute to disease pathogenesis. This review critically examines the experimental evidence underlying the various propositions made to explain how these antibodies may predispose to disease in humans. Furthermore, it also examines the evidence relating to the immunologic mechanisms that may contribute to the breakage of peripheral tolerance in this disorder. Delineating the strengths and limitations of the experimental evidence accumulated thus far will hopefully stimulate further experimentation toward achieving the ultimate goal of precisely defining the dominant pathogenic mechanisms operational in APS. This may pave the way for the development of improved therapies.
Tumor necrosis factor α triggers proliferation of adult neural stem cells via IKK/NF-κB signaling
Authors: Widera Darius , Mikenberg Ilja , Elvers Margitta , Kaltschmidt Christian , Kaltschmidt Barbara
Published: September 2006

Background

Brain inflammation has been recognized as a complex phenomenon with numerous related aspects. In addition to the very well-described neurodegenerative effect of inflammation, several studies suggest that inflammatory signals exert a potentially positive influence on neural stem cell proliferation, migration and differentiation. Tumor necrosis factor alpha (TNF-α) is one of the best-characterized mediators of inflammation. To date, conclusions about the action of TNF on neural stem or progenitor cells (NSCs, NPCs) have been conflicting. TNF seems to activate NSC proliferation and to inhibit their differentiation into NPCs. The purpose of the present study was to analyze the molecular signal transduction mechanisms induced by TNF and resulting in NSC proliferation.

Results

Here we describe for the first time the TNF-mediated signal transduction cascade in neural stem cells (NSCs) that results in increased proliferation. Moreover, we demonstrate IKK-α/β-dependent proliferation and markedly up-regulated cyclin D1 expression after TNF treatment. The significant increase in proliferation in TNF-treated cells was indicated by increased neurosphere volume, increased bromodeoxyuridin (BrdU) incorporation and a higher total cell number. Furthermore, TNF strongly activated nuclear factor-kappa B (NF-κB) as measured by reporter gene assays and by an activity-specific antibody. Proliferation of control and TNF-treated NSCs was strongly inhibited by expression of the NF-κB super-repressor IκB-AA1. Pharmacological blockade of IκB ubiquitin ligase activity led to comparable decreases in NF-κB activity and proliferation. In addition, IKK-β gene product knock-down via siRNA led to diminished NF-κB activity, attenuated cyclin D1 expression and finally decreased proliferation. In contrast, TGFβ-activated kinase 1 (TAK-1) is partially dispensable for TNF-mediated and endogenous proliferation. Understanding stem cell proliferation is crucial for future regenerative and anti-tumor medicine.

Conclusion

TNF-mediated activation of IKK-β resulted in activation of NF-κB and was followed by up-regulation of the bona-fide target gene cyclin D1. Activation of the canonical NF-κB pathway resulted in strongly increased proliferation of NSCs.
Managerial attitude to the implementation of quality management systems in Lithuanian support treatment and nursing hospitals
Authors: Buciuniene Ilona , Malciankina Sonata , Lydeka Zigmas , Kazlauskaite Ruta
Published: September 2006

Background

The regulations of the Quality Management System (QMS) implementation in health care organizations were approved by the Lithuanian Ministry of Health in 1998. Following the above regulations, general managers of health care organizations had to initiate the QMS implementation in hospitals. As no research on the QMS implementation has been carried out in Lithuanian support treatment and nursing hospitals since, the objective of this study is to assess its current stage from a managerial perspective.

Methods

A questionnaire survey of general managers of Lithuanian support treatment and nursing hospitals was carried out in the period of January through March 2005. Majority of the items included in the questionnaire were measured on a seven-point Likert scale. During the survey, a total of 72 questionnaires was distributed, out of which 58 filled-in ones were returned (response rate 80.6 per cent; standard sampling error 0.029 at 95 per cent level of confidence).

Results

Quality Management Systems were found operating in 39.7 per cent of support treatment and nursing hospitals and currently under implementation in 46.6 per cent of hospitals (13.7% still do not have it). The mean of the respondents' perceived QMS significance is 5.8 (on a seven-point scale). The most critical issues related to the QMS implementation include procedure development (5.5), lack of financial resources (5.4) and information (5.1), and development of work guidelines (4.6), while improved responsibility and power sharing (5.2), better service quality (5.1) and higher patient satisfaction (5.1) were perceived by the respondents as the key QMS benefits. The level of satisfaction with the QMS among the management of the surveyed hospitals is mediocre (3.6). However it was found to be higher among respondents who were more competent in quality management, were familiar with ISO 9000 standards, and had higher numbers of employees trained in quality management.

Conclusion

QMSs are perceived to be successfully running in one third of the Lithuanian support treatment and nursing hospitals. Its current implementation stage is dependent on the hospital size – the bigger the hospital the more success it meets in the QMS implementation. As to critical Quality Management (QM) issues, hospitals tend to encounter such major problems as lack of financial resources, information and training, as well as difficulties in procedure development. On the other hand, the key factors that assist to the success of the QMS implementation comprise managerial awareness of the QMS significance and the existence of employee training systems and audit groups in hospitals.
A comprehensive analysis of the androgen receptor gene and risk of breast cancer: results from the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3)
Authors: Cox David G , Blanché Hélène , Pearce Celeste L , Calle Eugenia E , Colditz Graham A , Pike Malcolm C , Albanes Demetrius , Allen Naomi E , Amiano Pilar , Berglund Goran , Boeing Heiner , Buring Julie , Burtt Noel , Canzian Federico , Chanock Stephen , Clavel-Chapelon Françoise , Feigelson Heather Spencer , Freedman Matthew , Haiman Christopher A , Hankinson Susan E , Henderson Brian E , Hoover Robert , Hunter David J , Kaaks Rudolf , Kolonel Laurence , Kraft Peter , LeMarchand Loic , Lund Eiliv , Palli Domenico , Peeters Petra HM , Riboli Elio , Stram Daniel O , Thun Michael , Tjonneland Anne , Trichopoulos Dimitrios , Yeager Meredith ,   the Breast and Prostate Cancer Cohort Consortium
Published: September 2006

Introduction

Androgens have been hypothesised to influence risk of breast cancer through several possible mechanisms, including their conversion to estradiol or their binding to the oestrogen receptor and/or androgen receptor (AR) in the breast. Here, we report on the results of a large and comprehensive study of the association between genetic variation in the AR gene and risk of breast cancer in the National Cancer Institute Breast and Prostate Cancer Cohort Consortium (BPC3).

Methods

The underlying genetic variation was determined by first sequencing the coding regions of the AR gene in a panel of 95 advanced breast cancer cases. Second, a dense set of markers from the public database was genotyped in a panel of 349 healthy women. The linkage disequilibrium relationships (blocks) across the gene were then identified, and haplotype-tagging single nucleotide polymorphisms (htSNPs) were selected to capture the common genetic variation across the locus. The htSNPs were then genotyped in the nested breast cancer cases and controls from the Cancer Prevention Study II, European Prospective Investigation into Cancer and Nutrition, Multiethnic Cohort, Nurses' Health Study, and Women's Health Study cohorts (5,603 breast cancer cases and 7,480 controls).

Results

We found no association between any genetic variation (SNP, haplotype, or the exon 1 CAG repeat) in the AR gene and risk of breast cancer, nor were any statistical interactions with known breast cancer risk factors observed.

Conclusion

Among postmenopausal Caucasian women, common variants of the AR gene are not associated with risk of breast cancer.
High Molecular Weight, Rather than Total, Adiponectin Levels Better Reflect Metabolic Abnormalities Associated with Childhood Obesity
Authors: Araki Shunsuke , Dobashi Kazushige , Kubo Kazuyasu , Asayama Kohtaro , Shirahata Akira
Published: September 2006

Context: Japanese are prone to obesity-induced metabolic derangement, which is linked to serum adipocytokine profile even in children.

Objective: The objective of the study was to determine whether high molecular-weight adiponectin (H-Adn) more specifically relates to metabolic derangement in obese children than total adiponectin (T-Adn).

Design and Setting: A case (n = 59) control (n = 28) study was performed at the pediatric clinic of a university hospital.

Patients: Japanese obese children (38 boys and 21 girls) were consecutively enrolled. The ages ranged from 5 to 15 (10.3 ± 0.3; mean ± sem) yr. Nonobese children (15 boys and 13 girls) were assigned as age-matched controls.

Main Outcome Measures: Serum adiponectin multimeric complexes were assayed by an ELISA kit. The relationship of adiponectin to metabolic abnormalities was evaluated.

Results: T-Adn (5.1 ± 0.2 vs. 8.8 ± 0.4 μg/ml), H-Adn (1.3 ± 0.1 vs. 4.8 ± 0.4 μg/ml), and medium molecular weight-Adn were significantly lower in obese than in control children. After adjustment for age and sex, both T- and H-Adn were inversely correlated with insulin and homeostasis model of assessment-insulin resistance, whereas H-Adn (but not T-Adn) inversely correlated with visceral fat area, as determined by computed tomography. Seven obese children were estimated to have metabolic syndrome and showed selective decrease in H-Adn and H/T-Adn.

Conclusion: H-Adn reflects metabolic abnormalities due to obesity better than T-Adn in children. H-Adn is associated with the development of metabolic syndrome, even in childhood.
Stationary partitions and Palm probabilities
Authors: Last Günter
Published: September 2006

A stationary partition based on a stationary point process N in ℝd is an ℝd-valued random field π={π(x): x∈ℝd} such that both π(y)∈N for each y∈ℝd and the random partition {{y∈ℝd: π(y)=x}: x∈N} is stationary jointly with N. Stationary partitions may be considered as general versions of the stationary random tessellations studied in stochastic geometry. As in the special case of the Voronoi tessellation, a stationary partition can be used to relate the underlying stationary probability measure to the associated Palm probability measure of N. In doing so, we will develop some basic theory for stationary partitions and extend properties of stationary tessellations to our more general case. One basic idea is that the stationary measure is (up to a shift) a weighted version of the Palm measure, where the weight is the volume of the typical cell. We will make systematic use of a known modified probability measure. Finally, we use our approach to extend some recent results on the shift coupling of the stationary distribution and the Palm distribution.
Some indexable families of restless bandit problems
Authors: Glazebrook K. D. , Ruiz-Hernandez D. , Kirkbride C.
Published: September 2006

In 1988 Whittle introduced an important but intractable class ofrestless bandit problemswhich generalise themultiarmed bandit problemsof Gittins by allowing state evolution for passive projects. Whittle's account deployed a Lagrangian relaxation of the optimisation problem to develop an index heuristic. Despite a developing body of evidence (both theoretical and empirical) which underscores the strong performance of Whittle's index policy, a continuing challenge to implementation is the need to establish that the competing projects all pass an indexability test. In this paper we employ Gittins' index theory to establish the indexability of (inter alia) general families of restless bandits which arise in problems of machine maintenance and stochastic scheduling problems with switching penalties. We also give formulae for the resulting Whittle indices. Numerical investigations testify to the outstandingly strong performance of the index heuristics concerned.
Normal approximation for random sums
Authors: Barbour A. D. , Xia Aihua
Published: September 2006

In this paper, we adapt the very effective Berry-Esseen theorems of Chen and Shao (2004), which apply to sums of locally dependent random variables, for use with randomly indexed sums. Our particular interest is in random variables resulting from integrating a random field with respect to a point process. We illustrate the use of our theorems in three examples: in a rather general model of the insurance collective; in problems in geometrical probability involving stabilizing functionals; and in counting the maximal points in a two-dimensional region.
Applications of factorization embeddings for Lévy processes
Authors: Dieker A. B.
Published: September 2006

We give three applications of the Pecherskii-Rogozin-Spitzer identity for Lévy processes. First, we find the joint distribution of the supremum and the epoch at which it is ‘attained’ if a Lévy process has phase-type upward jumps. We also find the characteristics of the ladder process. Second, we establish general properties of perturbed risk models, and obtain explicit fluctuation identities in the case that the Lévy process is spectrally positive. Third, we study the tail asymptotics for the supremum of a Lévy process under different assumptions on the tail of the Lévy measure.
Low peak bone mass and attenuated anabolic response to parathyroid hormone in mice with an osteoblast-specific deletion of connexin43
Authors: Chung Dong Jin , Castro Charlles H. M. , Watkins Marcus , Stains Joseph P. , Chung Min Young , Szejnfeld Vera Lucia , Willecke Klaus , Theis Martin , Civitelli Roberto
Published: September 2006

Connexin43 (Cx43) is involved in bone development, but its role in adult bone homeostasis remains unknown. To overcome the postnatal lethality of Cx43 null mutation, we generated mice with selective osteoblast ablation of Cx43, obtained using a Cx43fl allele and a 2.3-kb fragment of the α1(I) collagen promoter to drive Cre in osteoblasts (ColCre). Conditionally osteoblast-deleted ColCre;Cx43–/fl mice show no malformations at birth, but develop low peak bone mass and remain osteopenic with age, exhibiting reduced bone formation and defective osteoblast function. By both radiodensitometry and histology, bone mineral content increased rapidly and progressively in adult Cx43+/fl mice after subcutaneous injection of parathyroid hormone (PTH), an effect significantly attenuated in ColCre;Cx43–/fl mice, with Cx43–/fl exhibiting an intermediate response. Attenuation of PTH anabolic action was associated with failure to increase mineral apposition rate in response to PTH in ColCre;Cx43–/fl, despite an increased osteoblast number, suggesting a functional defect in Cx43-deficient bone-forming cells. In conclusion, lack of Cx43 in osteoblasts leads to suboptimal acquisition of peak bone mass, and hinders the bone anabolic effect of PTH. Cx43 represents a potential target for modulation of bone anabolism.
Adipophilin-enriched domains in the ER membrane are sites of lipid droplet biogenesis
Authors: Robenek Horst , Hofnagel Oliver , Buers Insa , Robenek Mirko J. , Troyer David , Severs Nicholas J.
Published: September 2006

The prevailing hypothesis of lipid droplet biogenesis proposes that neutral lipids accumulate within the lipid bilayer of the ER membrane from where they are budded off, enclosed by a protein-bearing phospholipid monolayer originating from the cytoplasmic leaflet of the ER membrane. We have used a variety of methods to investigate the nature of the sites of ER–lipid-droplet association in order to gain new insights into the mechanism of lipid droplet formation and growth. The three-dimensional perspectives provided by freeze-fracture electron microscopy demonstrate unequivocally that at sites of close association, the lipid droplet is not situated within the ER membrane; rather, both ER membranes lie external to and follow the contour of the lipid droplet, enclosing it in a manner akin to an egg cup (the ER) holding an egg (the lipid droplet). Freeze-fracture cytochemistry demonstrates that the PAT family protein adipophilin is concentrated in prominent clusters in the cytoplasmic leaflet of the ER membrane closely apposed to the lipid droplet envelope. We identify these structures as sites at which lipids and adipophilin are transferred from ER membranes to lipid droplets. These findings call for a re-evaluation of the prevailing hypothesis of lipid droplet biogenesis.
Calcium signalling during excitation-contraction coupling in mammalian atrial myocytes
Authors: Bootman Martin D. , Higazi Daniel R. , Coombes Stephen , Roderick H. Llewelyn
Published: September 2006

Atrial cardiomyocytes make an important contribution to the refilling of ventricles with blood, which enhances the subsequent ejection of blood from the heart. The dependence of cardiac function on the contribution of atria becomes increasingly important with age and exercise. We know much less about the calcium signals that link electrical depolarisation to contraction within atrial myocytes in comparison with ventricular myocytes. Nevertheless, recent work has shed new light on calcium signalling in atrial cells. At an ultrastructural level, atrial and ventricular myocytes have many similarities. However, a few key structural differences, in particular the lack of transverse tubules (`T-tubules') in atrial myocytes, make these two cell types display vastly different calcium patterns in response to depolarisation. The lack of T-tubules in atrial myocytes means that depolarisation provokes calcium signals that largely originate around the periphery of the cells. To engage the contractile machinery, the calcium signal must propagate centripetally deeper into the cells. This inward movement of calcium is ultimately controlled by hormones that can promote or decrease calcium release within the myocytes. Enhanced centripetal movement of calcium in atrial myocytes leads to increased contraction and a more substantial contribution to blood pumping. The calcium signalling paradigm within atrial cells applies to other cardiac cell types that also do not express T-tubules, such as neonatal ventricular myocytes, and Purkinje cells that aid in the spread of electrical depolarisation. Furthermore, during heart failure ventricular myocytes progressively lose their regular T-tubule expression, and their pattern of response resembles that of atrial cells.
Role of the Pharmacist in the Community: From Corner Drug Store to Corner Pharmacy in 40 Years with Friends Like Harvey
Authors: Robinson J Daniel
Published: September 2006

2006 marks the 40th year of publication for The Annals. Over that time, The Annals has been an important contributor to the development of clinical pharmacy. Throughout 2006, we are publishing articles reflecting on the history of clinical pharmacy through the eyes of practitioners, including those pioneering clinical pharmacy, as well as those who have more recently entered the profession and a well-established specialty. In addition, we are also presenting articles and editorials from the early history of The Annals that have given direction and shape to the practice of clinical pharmacy (see page 1857).
Peripheral Myelin Maintenance Is a Dynamic Process Requiring ConstantKrox20Expression
Authors: Decker Laurence , Desmarquet-Trin-Dinh Carole , Taillebourg Emmanuel , Ghislain Julien , Vallat Jean-Michel , Charnay Patrick
Published: September 2006

Onset of myelination in Schwann cells is governed by several transcription factors, including Krox20/Egr2, and mutations affectingKrox20result in various human hereditary peripheral neuropathies, including congenital hypomyelinating neuropathy (CHN) and Charcot-Marie-Tooth disease (CMT). Similar molecular information is not available on the process of myelin maintenance. We have generated conditionalKrox20mutations in the mouse that allowed us to develop models for CHN and CMT. In the latter case, specific inactivation ofKrox20in adult Schwann cells results in severe demyelination, involving rapid Schwann cell dedifferentiation and increased proliferation, followed by an attempt to remyelinate and a block at the promyelinating stage. These data establish that Krox20 is not only required for the onset of myelination but that it is also crucial for the maintenance of the myelinating state. Furthermore, myelin maintenance appears as a very dynamic process in which Krox20 may constitute a molecular switch between Schwann cell myelination and demyelination programs.
Neurotrophin-3 Gradients Established by Lentiviral Gene Delivery Promote Short-Distance Axonal Bridging beyond Cellular Grafts in the Injured Spinal Cord
Authors: Taylor Laura , Jones Leonard , Tuszynski Mark H. , Blesch Armin
Published: September 2006

Neurotrophic factor delivery to sites of spinal cord injury (SCI) promotes axon growth into but not beyond lesion sites. We tested the hypothesis that sustained growth factor gradients beyond regions of SCI will promote significant axonal bridging into and beyond lesions. Adult rats underwent C3 lesions to transect ascending dorsal column sensory axons, and autologous bone marrow stromal cells were grafted into the lesion to provide a cellular bridge for growth into the injured region. Concurrently, lentiviral vectors expressing neurotrophin-3 (NT-3) or green fluorescent protein (GFP) (controls) were injected into the host cord rostral to the lesion to promote axon extension beyond the graft/lesion. Four weeks later, NT-3 gradients beyond the lesion were detectable by ELISA in animals that received NT-3-expressing lentiviral vectors, with highest average NT-3 levels located near the rostral vector injection site. Significantly more ascending sensory axons extended into tissue rostral to the lesion site in animals injected with NT-3 vectors compared with GFP vectors, but only if the zone of NT-3 vector transduction extended continuously from the injection site to the graft; any “gap” in NT-3 expression from the graft to rostral tissue resulted in axon bridging failure. Despite axon bridging beyond the lesion, regenerating axons did not continue to grow over very long distances, even in the presence of a continuing growth factor gradient beyond the lesion. These findings indicate that a localized and continuous gradient of NT-3 can achieve axonal bridging beyond the glial scar, but growth for longer distances is not sustainable simply with a trophic stimulus.
Vanilloid-Mediated Heterosynaptic Facilitation of Inhibitory Synaptic Input to Neurons of the Rat Dorsal Motor Nucleus of the Vagus
Authors: Derbenev Andrei V. , Monroe Michael J. , Glatzer Nicholas R. , Smith Bret N.
Published: September 2006

Vanilloid type-1 receptors (VR1) are abundant in the dorsal vagal complex, where their function is mostly unknown. We examined the role of VR1 in regulating synaptic inputs to neurons of the dorsal motor nucleus of the vagus (DMV). Using patch-clamp recordings from DMV neurons in brainstem slices, capsaicin was found to increase action potential-independent inhibitory input onto DMV neurons. This rapid effect was mimicked by application of the endogenous cannabinoid, anandamide and blocked by VR1 antagonists. The VR1-mediated facilitation of synaptic inhibition was reduced by ionotropic and metabotropic glutamate receptor antagonists, suggesting an indirect, heterosynaptic enhancement of GABA release caused by a VR1-mediated increase in glutamate release from presynaptic terminals of excitatory neurons. Application ofl-glutamate also increased GABA release. The paired-pulse ratio was increased for IPSCs evoked after electrical stimulation of the nucleus tractus solitarius, but the effect was slower than for the enhancement of spontaneous and miniature IPSCs. Capsaicin also increased the frequency of glutamatergic postsynaptic currents in a VR1-mediated manner. Results of these studies suggest that VR1-containing glutamatergic terminals contact DMV neurons. Activation of VR1 potently enhances glutamate release onto GABAergic terminals, facilitating GABA release. Endogenous cannabinoids can thereby rapidly enhance inhibitory input to DMV neurons via VR1-mediated presynaptic mechanisms.
Kv2.1 Potassium Channels Are Retained within Dynamic Cell Surface Microdomains That Are Defined by a Perimeter Fence
Authors: O'Connell Kristen M. S. , Rolig Annah S. , Whitesell Jennifer D. , Tamkun Michael M.
Published: September 2006

Ion channel localization to specific cell surface regions is essential for proper neuronal function. The Kv2.1 K+channel forms large clusters on the plasma membrane of hippocampal neurons and transfected human embryonic kidney (HEK) cells. Using live cell imaging, we address mechanisms underlying this Kv2.1 clustering in both HEK cells and cultured hippocampal neurons. The Kv2.1-containing surface clusters have properties unlike those expected for a scaffolding protein bound channel. After channel is delivered to the plasma membrane via intracellular transport vesicles, it remains localized at the insertion site. Fluorescence recovery after photobleaching (FRAP) and quantum dot tracking experiments indicate that channel within the surface cluster is mobile (FRAP, τ = 14.1 ± 1.5 and 11.5 ± 6.1 s in HEK cells and neurons, respectively). The cluster perimeter is not static, because after fusion of adjacent clusters, green fluorescent protein (GFP)–Kv2.1 completely exchanged between the two domains within 60 s. Treatment of hippocampal neurons expressing GFP-Kv2.1 with 5 μmlatrunculin A resulted in a significant increase in average cluster size from 0.89 ± 0.16 μm2to 12.15 ± 1.4 μm2with a concomitant decrease in cluster number. Additionally, Kv2.1 was no longer restricted to the cell body, suggesting a role for cortical actin in both cluster maintenance and localization. Thus, Kv2.1 surface domains likely trap mobile Kv2.1 channels within a well defined, but fluid, perimeter rather than being tightly bound to a scaffolding protein-containing complex. Channel moves directly into these clusters via trafficking vesicles. Such domains allow for efficient trafficking to the cell surface while sequestering channel with signaling proteins.
Real-Time Contributions of Auditory Feedback to Avian Vocal Motor Control
Authors: Sakata Jon T. , Brainard Michael S.
Published: September 2006

Songbirds and humans both rely critically on hearing for learning and maintaining accurate vocalizations. Evidence strongly indicates that auditory feedback contributes in real time to human speech, but similar contributions of feedback to birdsong remain unclear. Here, we assessed real-time influences of auditory feedback on Bengalese finch song using a computerized system to detect targeted syllables as they were being sung and to disrupt feedback transiently at short and precisely controlled latencies. Altered feedback elicited changes within tens of milliseconds to both syllable sequencing and timing in ongoing song. These vocal disruptions were larger when feedback was altered at segments of song with variable sequence transitions than at stereotyped sequences. As in humans, these effects depended on the feedback delay relative to ongoing song, with the most disruptive delays approximating the average syllable duration. These results extend the parallels between speech and birdsong with respect to a moment-by-moment reliance on auditory feedback. Moreover, they demonstrate that song premotor circuitry is sensitive to auditory feedback during singing and suggest that feedback may contribute in real time to the control and calibration of song.
Netrin-1 Signaling RegulatesDe NovoProtein Synthesis of κ Opioid Receptor by Facilitating Polysomal Partition of Its mRNA
Authors: Tsai Nien-Pei , Bi Jing , Loh Horace H. , Wei Li-Na
Published: September 2006

The expression of κ opioid receptor (KOR) is subjected to both transcriptional and posttranscriptional controls. We report that KOR translation is regulated by netrin-1 in primary neurons of dorsal root ganglion (DRG) and in P19 embryonal carcinoma cells. Without stimulation, a significant portion of KOR mRNA is maintained in a dormant state and partitions in the translationally inactive, post-polysomal fraction. During netrin-1 stimulation, which activates its downstream target focal adhesion kinase (FAK), KOR mRNA rapidly partitions to the translationally active polysomal fraction. Functionally, the newly synthesized KOR proteins in DRG neurons are able to bind to specific ligands. This report describes the first example of netrin-1 signaling in the translational control of a drug receptor KOR, which involves the mediator of netrin-1, FAK, and a novel mechanism that enhances the association of target mRNA with polysomes for translational activation.
Monkey Sound Localization: Head-Restrained versus Head-Unrestrained Orienting
Authors: Populin Luis C.
Published: September 2006

The sound localization abilities of three rhesus monkeys were tested under head-restrained and head-unrestrained conditions. Operant conditioning and the magnetic search coil technique were used to measure eye and head movements to sound sources. Whereas the results support previous findings that monkeys localize sounds very poorly with their heads restrained, the data also reveal for the first time that monkeys localize sounds much more accurately and with less variability when their heads are allowed to move. Control experiments using acoustic stimuli known to produce spatial auditory illusions such as summing localization confirmed that the monkeys based their orienting on localizing the sound sources and not on remembering spatial locations that resulted in rewards. Overall, the importance of using ecologically valid behaviors for studies of sensory processes is confirmed, and the potential of the rhesus monkey, the model closest to human, for studies of spatial auditory function, is established.
Frontoparietal Activity with Minimal Decision and Control
Authors: Hon Nicholas , Epstein Russell A. , Owen Adrian M. , Duncan John
Published: September 2006

In the human brain, a well known frontoparietal circuit, including lateral prefrontal cortex (LPFC), presupplementary motor area/anterior cingulate cortex (pre-SMA/ACC), and both the superior and inferior parietal cortex, is involved in cognitive control. One proposal is that the frontoparietal cortex holds a flexible description of attended or task-relevant information, biasing processing in favor of this information in many different parts of the brain. Here, we separate frontoparietal coding of attended information from its active use in behavior. In two experiments, subjects watch a stream of visual stimuli in a fixed location. In the first experiment, there is no task to perform; in the second, decisions are orthogonal to the occurrence of new stimulus events. Even in these simple circumstances, we find that attended stimulus changes give extensive activation of LPFC, pre-SMA/ACC and parietal cortex, whereas unattended changes do not. Even without behavior to control, these classical “control” regions are active in simple update of attended information.
SKY'S THE LIMIT
Authors: HERBERT DANIEL
Published: September 2006

ABSTRACT This essay examines the production circumstances of intertextual relations, and discursive contexts of Abre los Ojos (1997) and its remake Vanilla Sky (2001). Seen in combination, these films demonstrate a struggle for cultural power in a transnational field and provide notably different representations of transnational identities.
Using Preemergence Herbicides to Improve Establishment of Centipedegrass (Eremochloa ophiuroides) from Seed
Authors: Ferrell Jason A. , Murphy Tim R. , Webster Theodore M.
Published: September 2006

Centipedegrass is a warm-season turf grass that has increased in popularity in recent years. However, more information is needed on the use of herbicides during centipedegrass establishment from seed, particularly in seed and sod production systems. The intent of this study was to evaluate turf-grass injury and weed control when atrazine, imazapic, imazethapyr, and simazine are applied immediately after seeding centipedegrass. Atrazine and simazine (applied at 1.1, 2.2, and 4.4 kg ai/ ha) injured centipedegrass less than 15% at 5 wk after treatment (WAT) in 2001. Imazethapyr and imazapic (applied at 0.04, 0.07, and 0.1 kg ai/ha) injured centipedegrass between 7 and 13%, 5 WAT, in 2001 and from 30 to 77% in 2002. Herbicide and application rate also affected centipedegrass cover. At 3 WAT, cover decreased with all herbicides as application rate increased. At 12 WAT in both years, centipedegrass cover increased as atrazine application rate increased and imazethapyr application rate decreased. Imazapic and simazine were less consistent, causing increases in cover one year and decreases, or no change, the next. Imazapic controlled Texas panicum 80 to 89% and was more effective than any other herbicide. Atrazine and simazine controlled crowfootgrass better than any other herbicide. Imazethapyr often injured centipedegrass and failed to control weeds. Atrazine effectively controlled grass and broadleaf weeds with minimal centipedegrass injury. Imazethapyr and imazapic were too injurious to permit usage during centipedegrass establishment from seed.
Selective Weed Control in Syrian Marjoram (Origanum syriacum) with Oxadiazon and Oxyfluorfen Herbicides
Authors: Qasem Jamal R. , Foy Chester L.
Published: September 2006

Field experiments were conducted to study the effects of oxadiazon and oxyfluorfen on weeds and Syrian marjoram (Origanum syriacumL.) in the central Jordan Valley during the period from 1998 to 2001. Results showed that weed competition with marjoram for the whole growing period resulted in almost complete crop failure. Oxyfluorfen and oxadiazon applied preplanting or postplanting to marjoram controlled weeds effectively, resulted in significant increase in marjoram shoot fresh and dry weight yields and in more branches per plant compared with the weed-infested control. High marjoram yield was obtained with oxyfluorfen applied at 0.72 kg ai/ha in preplanting treatment and with oxadiazon at 1.25 and 0.75 kg ai/ha in pre- and postplanting treatments, respectively. In preplanting treatment, 0.36 kg ai/ha of oxyfluorfen was highly selective, but 1.44 kg ai/ha reduced marjoram yield. Conflicting results were obtained with oxadiazon under the same treatments. In postplanting, oxyfluorfen at 0.24 and 0.96 kg ai/ha significantly increased marjoram yield over the weed-infested control. However, the highest shoot dry weight of marjoram was obtained at 0.96 kg ai/ha of this herbicide. In contrast, the low rate (0.38 kg ai/ha) of oxadiazon was highly selective and increased marjoram yield, but the herbicide failed to increase yield beyond the weed-infested control when the higher rate (1.5 kg ai/ha) was used. Results showed that both oxyfluorfen and oxadiazon herbicides were highly selective and effective for weed control in Syrian marjoram, providing normal rates of both are used, although high rates of the two herbicides were also selective and increased marjoram yield over the weed-infested control.
Growth, Reproduction, and Management of Chinese Yam (Dioscorea oppositifolia)
Authors: Main Christopher L. , Beeler Joseph E. , Robinson Darren K. , Mueller Thomas C.
Published: September 2006

Chinese yam is an exotic perennial vine that invades natural areas in the temperate regions of the eastern United States. Research was conducted from 2001 to 2004 to evaluate growth, reproduction, and management options for this weed. Vine length, lateral shoot production, and reproductive capacity were lower in the first year of growth compared to 2 subsequent years. During the second and third growing season, plants were more mature and tended to flower earlier and produce larger bulbils compared to the first growing season. Maximum vine length was not reached prior to frost in the first year and was approximately 480 cm in each of the subsequent years. Both glyphosate and triclopyr were effective in controlling plants growing from bulbils and plants growing from tubers. Triclopyr did not display acropetal translocation, in that only the treated tissue died. However, both products displayed excellent basipetal translocation resulting in elimination of tubers and no shoot regrowth the year following treatment. Native area managers should attempt to eradicate small populations of Chinese yam prior to establishment of an extensive tuber system.
Identification, Distribution, and Control of Italian Ryegrass (Lolium multiflorum) Ecotypes with Varying Levels of Sensitivity to Triasulfuron in Texas
Authors: Tucker Kevin P. , Morgan Gaylon D. , Senseman Scott A. , Miller Travis D. , Baumann Paul A.
Published: September 2006

Texas wheat producers have observed reduced efficacy and failure to control Italian ryegrass with registered rates of sulfonylurea herbicides that were previously effective. Growth chamber studies were conducted to quantify the sensitivity and distribution of Italian ryegrass ecotypes in Texas to triasulfuron and to determine alternative herbicide management options. Italian ryegrass seed samples were collected from over 40 wheat fields in 13 central and north Texas counties where declining Italian ryegrass control was reported by farmers following sulfonylurea herbicide application(s). Two-leaf Italian ryegrass was screened with an application of 150 g ai/ha triasulfuron, a rate five times the registered herbicide use rate. Sensitivity was determined by the response of an ecotype to that of a known susceptible population. Of the 48 Italian ryegrass ecotypes sampled, nine were comparable to susceptible standard, while the remaining 39 ecotypes were less sensitive to triasulfuron. Four of the least sensitive ecotypes to triasulfuron plus the susceptible standard were selected for a subsequent study. Diclofop, clodinafop, and metribuzin reduced fresh weights by at least 69, 71, and 62% across all ecotypes. No imazamox or triasulfuron treatment reduced fresh weights more than 60%.
Temperature Influences Creeping Bentgrass (Agrostis stolonifera) and Annual Bluegrass (Poa annua) Response to Bispyribac-Sodium
Authors: McCullough Patrick E. , Hart Stephen E.
Published: September 2006

Bispyribac-sodium is a POST herbicide that selectively controls annual bluegrass in creeping bentgrass, but inconsistent results with seasonal applications are believed to occur from temperature influences on bispyribac-sodium efficacy. Growth chamber experiments at the New Jersey Experimental Greenhouse Research Complex, New Brunswick, NJ, investigated three temperature regimes on ‘L-93’ creeping bentgrass and annual bluegrass responses to bispyribac-sodium. Annual bluegrass and creeping bentgrass exhibited contrasting responses to bispyribac-sodium as temperature increased from 10 to 30 C. Regressions of 4 week after treatment (WAT) data revealed as temperature increased from 10 to 30 C, required bispyribac-sodium rates for 50% clipping reduction (CR50) of annual bluegrass decreased from 85 to 31 g ai/ha and required rates for 50% leaf chlorosis decreased from greater than 296 to 98, indicating increased herbicidal efficacy at higher temperatures. In contrast, required bispyribac-sodium rates for creeping bentgrass CR50increased from 200 to greater than 296 as temperature increased from 10 to 30 C. Bispyribac-sodium discolored creeping bentgrass 0 to 20% at 20 and 30 C and discoloration increased 10 to 50% at 10 C. Thus, warmer temperatures (20 and 30 C) increase bispyribac-sodium efficacy for annual bluegrass control with minimal bentgrass discoloration; however, cooler temperatures (10 C) have minimal efficacy on annual bluegrass and increase bentgrass chlorosis.
Tolerance of ‘Salam’ Seashore Paspalum (Paspalum vaginatum) to Postemergence Herbicides
Authors: Unruh J. Bryan , Stephenson Daniel O. , Brecke Barry J. , Trenholm Laurie E.
Published: September 2006

Field studies were conducted to assess the tolerance of seashore paspalum (‘Salam’) to postemergence (POST) herbicides in Florida in 2000 and 2001. POST applications of bentazon (2,200 g/ha), clopyralid (420 g/ha), dicamba (280 g/ha), halosulfuron (70 g/ha), imazaquin (420 g/ha), mecoprop + 2,4-D + dicamba (160 + 180 + 40 g/ha), metsulfuron (30 g/ha), and quinclorac (1,700 g/ha) resulted in ≤10% injury 7 and 15 d after treatment (DAT), indicating their safety for POST application. Clethodim (280 g/ha) and sethoxydim (310 g/ha) caused 67 and 46% injury, respectively, 15 DAT averaged across 2000 and 2001. Ethofumesate was inconsistent between years, causing 30 and 60% injury 7 and 15 DAT, respectively, in 2000, but only 5 and 13% 7 and 15 DAT, respectively, in 2001. Imazapic and trifloxysulfuron-sodium caused an average of 47% injury 7 DAT in 2000 and 45% injury 15 DAT in 2001. Clethodim, ethofumesate, imazapic, sethoxydim, and trifloxysulfuron-sodium can not be safely applied POST to Salam seashore paspalum; however, bentazon, clopyralid, dicamba, halosulfuron, imazaquin, mecoprop + 2,4-D + dicamba, metsulfuron, and quinclorac are safe.
Wetland Nightshade (Solanum tampicense) Growth Response to Temperature, and Winter Survival, in Relation to Potential Spread
Authors: Bryson Charles T. , Fox Alison M. , Byrd John D.
Published: September 2006

Greenhouse, growth chamber, and winter survival studies were conducted at Stoneville, MS from 1996 to 2002 to determine growth, time to first flower, and winter survival of wetland nightshade. At 12 wk after emergence, wetland nightshade plants had 58-, 45-, 48-, and 4-cm heights, respectively; 24, 21, 21, and 12 nodes/plant, respectively; 62, 31, 36, and 21 leaves/plant, respectively; and 7.1, 3.9, 5.1, and 0.3 g/plant dry weights, respectively, at temperatures of 26/36, 20/30, 14/24, and 8/18 (±0.5) C at the 14/10 day/night length. Flowering occurred at 79, 85, and 85 days after emergence at 26/36, 20/30, and 14/24 C night/day, respectively at the 14/10 day/night cycle. Wetland nightshade plants did not flower at 8/18 C. Wetland nightshade growth was adequate for flowering and fruit production in additional areas of the southeastern United States with night/day temperatures greater than or equal to 14/24 C. Winter survival was greater than or equal to 33% for established wetland nightshade plants in 5 of 6(1996 to 2002) above water levels and 82% from 20 cm below the water surface. Based on these results, wetland nightshade has the potential to continue to spread in the United States.
Using Soil-Applied Herbicides in Glyphosate-Resistant Soybeans along the Texas Gulf Coast
Authors: Grichar W. James
Published: September 2006

Field studies were conducted at four locations over a 2-year period to evaluate the utility of soil-applied herbicides and glyphosate timing for weed control and soybean yield. Pendimethalin,S-metolachlor plus metribuzin, and flufenacet plus metribuzin were applied pre-emergence (PRE) alone or followed by glyphosate applied early postemergence (EPOST), late postemergence (LPOST), or EPOST plus LPOST. Soil-applied herbicides or glyphosate alone failed to control (<45%) broadleaf signalgrass in 2003 due to late-season rainfall, which accounted for a late flush of growth. In 2004, soil-applied herbicides alone controlled 79–100% broadleaf signalgrass, whereas glyphosate alone or in combination with soil-applied herbicides controlled at least 99%. Barnyardgrass and tall waterhemp were controlled at least 87% with soil-applied herbicides alone and at least 95% when glyphosate was used alone or in combination with a soil-applied herbicide. Soybean yield varied, but at only one location did herbicide treatments produce higher yields than the untreated check. Under low to moderate weed pressure, the use of a soil-applied herbicide followed by glyphosate failed to increase net returns over soil-applied herbicides alone.