bluuebunny/crossref_metadata_2025 huggingface dataset:
SteerBench: a benchmark suite for evaluating steering behaviors
Authors: Singh Shawn , Kapadia Mubbasir , Faloutsos Petros , Reinman Glenn
Published: February 2009

Steering is a challenging task, required by nearly all agents in virtual worlds. There is a large and growing number of approaches for steering, and it is becoming increasingly important to ask a fundamental question: how can we objectively compare steering algorithms? To our knowledge, there is no standard way of evaluating or comparing the quality of steering solutions. This paper presents SteerBench: a benchmark framework for objectively evaluating steering behaviors for virtual agents. We propose a diverse set of test cases, metrics of evaluation, and a scoring method that can be used to compare different steering algorithms. Our framework can be easily customized by a user to evaluate specific behaviors and new test cases. We demonstrate our benchmark process on two example steering algorithms, showing the insight gained from our metrics. We hope that this framework can grow into a standard for steering evaluation. Copyright © 2009 John Wiley & Sons, Ltd.
Colon cancer patient information seeking and the adoption of targeted therapy for on‐label and off‐label indications
Authors: Gray Stacy W. , Armstrong Katrina , DeMichele Angela , Schwartz J. Sanford , Hornik Robert C.
Published: February 2009

BACKGROUND:

Despite the rise in publicly available cancer information, little is known about the association between patient information seeking and the adoption of cancer technologies. The authors of this report investigated the relation between patient information seeking and awareness about and receipt of novel targeted therapy (TT) for colon cancer among patients for whom therapy is approved by the US Food and Drug Administration (FDA) and among patients for whom therapy is not FDA approved.

METHODS:

A retrospective, population‐based survey of 633 colon cancer patients were identified through the Pennsylvania Cancer Registry. Outcome measures were self‐reported awareness about and receipt of TT (bevacizumab and cetuximab).

RESULTS:

After adjusting for sociodemographic characteristics, high levels of treatment information seeking were associated strongly with hearing about TT (odds ratio [OR], 2.83; 95% confidence interval [CI], 1.49‐5.38) and receiving TT (OR, 3.22; 95% CI, 1.36‐7.62). These associations were present for patients with metastatic disease, for whom the use of TT is FDA approved, and for patients with localized disease, for whom the use of TT is not FDA approved (P for interactions = .29). Internet use (OR, 2.88; 95% CI, 1.40‐5.94) and newspaper/magazine use (OR, 3.44; 95% CI, 1.34‐8.84) were associated with hearing about TT. Seeking information from nontreating physicians was associated with hearing about TT (OR, 1.95; 95% CI, 1.03‐3.68) and receiving TT (OR, 2.64; 95% CI, 1.16‐5.97).

CONCLUSIONS:

Patient information seeking was related to the adoption of TT for colon cancer in both appropriate and inappropriate clinical settings. These findings emphasize the importance of exploring patient influence on physician prescribing patterns and understanding the impact of information seeking on cancer outcomes. Cancer 2009. © 2009 American Cancer Society.
Neoplastic meningitis
Authors: Chamberlain Marc C. , Johnston Sandra K.
Published: February 2009

BACKGROUND:

This retrospective comparison evaluated survival in 2 well‐matched cohorts of patients with neoplastic meningitis (NM) presenting with or without positive cerebrospinal fluid (CSF) cytology.

METHODS:

Two patient cohorts were studied: 42 individuals with (Group A) and 42 without (Group B) positive CSF cytology. Groups were matched with respect to age; primary tumor; Karnofsky performance status; site of NM disease (cranial nerves or spinal cord); treatment (radiotherapy and chemotherapy; systemic and intraventricular); and absence of CSF compartmentalization, NM‐related encephalopathy, and neuroradiographic bulky central nervous system disease. Primary tumor histology included breast (28 patients), non‐Hodgkin lymphoma (14 patients), nonsmall cell lung cancer (14 patients), melanoma (12 patients), and others (16 patients). NM at presentation revealed cranial neuropathy (40 patients) or spinal cord dysfunction (58 patients). Radiotherapy was administered to 69 patients (whole brain only in 14 patients [7 each in Groups A and B], restricted spine only in 51 patients [25 in Group A and 26 in Group B], and both whole brain and restricted spine in 4 patients [2 each in Groups A and B]). All patients received intraventricular chemotherapy and 60 (30 each in Groups A and B) received concurrent tumor‐specific systemic chemotherapy.

RESULTS:

The median, 3‐month, 6‐month, and 12‐month survival rates for patients with NM were not significantly different between those patients with positive CSF cytology (18 weeks, 83%, 33%, and 9.5%, respectively) and those without positive CSF cytology (20 weeks, 90.5%, 40.5%, and 9.5%, respectively). All patients demonstrated progressive disease and died of either NM or systemic cancer.

CONCLUSIONS:

In patients with NM who were matched for known prognostic variables, the presence or absence of CSF cytology did not appear to influence survival. Cancer 2009. © 2009 American Cancer Society.
Spinal cord compression injury in adult rats initiates changes in dorsal horn remodeling that may correlate with development of neuropathic pain
Authors: Kalous Adrianna , Osborne Peregrine B. , Keast Janet R.
Published: February 2009

Spinal cord injury commonly causes chronic, neuropathic pain. The mechanisms are poorly understood but may include structural plasticity within spinal and supraspinal circuits. Our aim was to determine whether structural remodeling within the dorsal horn rostral to an incomplete injury differs from a complete spinal cord transection. Four immunohistochemical populations of primary afferent C‐fibers, and descending catecholamine and serotonergic projections, were examined in segments T9–T12 at 2 and 12 weeks after a T13 clip‐compression injury in adult male rats. Dorsal root ganglia were also examined. Two weeks after injury, fibers immunoreactive for calcitonin gene‐related peptide (CGRP) or GDNF‐family receptors (GFRα1, GFRα2, GFRα3) showed distinct injury responses within the superficial dorsal horn. CGRP fibers decreased, but GFRα1, GFRα2 and GFRα3 fibers did not change. In contrast, all groups were decreased by 12 weeks after injury. Catecholamine fibers showed a decrease at 2 weeks followed by an increase in density at 12 weeks, whereas serotonergic fibers showed a decrease (restricted to deep dorsal horn) at 12 weeks. These results show that the dorsal horn of the spinal cord undergoes substantial structural plasticity rostral to a compression injury, with the most profound effect being a prolonged and possibly permanent loss of primary afferent fibers. This loss was more extensive and more prolonged than the loss that follows spinal cord transection. Our results provide further evidence that anatomical reorganization of sensory and nociceptive dorsal horn circuits rostral to an injury could factor in the development or maintenance of spinal cord injury pain. J. Comp. Neurol. 513:668–684, 2009. © 2009 Wiley‐Liss, Inc.
Systemic hypothermia improves histological and functional outcome after cervical spinal cord contusion in rats
Authors: Lo Thomas Pang , Cho Kyoung‐Suok , Garg Maneesh Sen , Lynch Michael Patrick , Marcillo Alexander Eduardo , Koivisto Denise Leigh , Stagg Monica , Abril Rosa Marie , Patel Samik , Dietrich W. Dalton , Pearse Damien Daniel
Published: February 2009

Hypothermia has been employed during the past 30 years as a therapeutic modality for spinal cord injury (SCI) in animal models and in humans. With our newly developed rat cervical model of contusive SCI, we investigated the therapeutic efficacy of transient systemic hypothermia (beginning 5 minutes post‐injury for 4 hours, 33°C) with gradual rewarming (1°C per hour) for the preservation of tissue and the prevention of injury‐induced functional loss. A moderate cervical displacement SCI was performed in female Fischer rats, and behavior was assessed for 8 weeks. Histologically, the application of hypothermia after SCI resulted in significant increases in normal‐appearing white matter (31% increase) and gray matter (38% increase) volumes, greater preservation (four‐fold) of neurons immediately rostral and caudal to the injury epicenter, and enhanced sparing of axonal connections from retrogradely traced reticulospinal neurons (127% increase) compared with normothermic controls. Functionally, a faster rate of recovery in open field locomotor ability (BBB score, weeks 1–3) and improved forelimb strength, as measured by both weight‐supported hanging (43% increase) and grip strength (25% increase), were obtained after hypothermia. The current study demonstrates that mild systemic hypothermia is effective for retarding tissue damage and reducing neurological deficits following a clinically relevant contusive cervical SCI. J. Comp. Neurol. 514:433–448, 2009. © 2009 Wiley‐Liss, Inc.
Variability in the occurrence of nitric oxide synthase immunoreactivity in different populations of rat sympathetic preganglionic neurons
Authors: Hinrichs Julia M. , Llewellyn‐Smith Ida J.
Published: February 2009

The proportion of sympathetic preganglionic neurons (SPN) showing nitric oxide synthase (NOS) immunoreactivity appears to vary with innervation target and blood pressure level. For normotensive Sprague‐Dawley rats (SD), we evaluated peroxidase immunolabelling for choline acetyltransferase (ChAT) plus NOS in spinal cord segments T1–L2 and assessed NOS immunofluorescence in SPN retrogradely labelled with cholera toxin B subunit from the adrenal medulla (AM) or superior cervical (SCG), coeliac (CG), or major pelvic (MPG) ganglia. We also compared the distributions and numbers of NOS‐positive and NOS‐negative/ChAT‐positive lateral horn neurons in SD with those in normotensive Wistar‐Kyoto (WKY) and spontaneously hypertensive rats (SHR). In SD, WKY, and SHR, rostrocaudal, dorsoventral, and mediolateral differences occurred in the distributions of NOS‐positive and NOS‐negative/ChAT‐positive neurons in the intermediolateral cell column (IML), whereas the two groups were similarly distributed throughout the central autonomic area (CAA). Among the four retrogradely labelled populations of SPN, the percentages showing NOS immunoreactivity differed (CG‐projecting, 54.8% ± 0.7%; SCG‐projecting, 75.3% ± 1.2%; MPG‐projecting, 89% ± 1.1% and AM‐projecting, 98.6% ± 0.2%). Within each retrogradely labelled group of SPN, the NOS‐positive proportion also varied with subnuclear location (e.g., 25.5% ± 4.0% of CG‐projecting SPN in the CAA vs. 82.7% ± 7.6% of CG‐projecting SPN in the dorsolateral funiculus). The numbers of NOS‐positive and NOS‐negative/ChAT‐positive neurons in T9–T11 were the same in SD and SHR but differed in WKY. Our results show that the expression of NOS within SPN varies depending on the target that they innervate and also on their subnuclear location. Our data indicate that there are no anatomical differences between nitric oxide‐synthesizing SPN in normotensive SD and hypertensive SHR. J. Comp. Neurol. 514:492–506, 2009. © 2009 Wiley‐Liss, Inc.
Regulation of neonatal development of retinal ganglion cell dendrites by neurotrophin‐3 overexpression
Authors: Liu Xiaorong , Robinson Michael L. , Schreiber Ann Marie , Wu Vincent , Lavail Matthew M. , Cang Jianhua , Copenhagen David R.
Published: February 2009

The morphology of dendrites constrains and reflects the nature of synaptic inputs to neurons. The visual system has served as a useful model to show how visual function is determined by the arborization patterns of neuronal processes. In retina, light ON and light OFF responding ganglion cells selectively elaborate their dendritic arbors in distinct sublamina, where they receive, respectively, inputs from ON and OFF bipolar cells. During neonatal maturation, the bilaminarly distributed dendritic arbors of ON‐OFF retinal ganglion cells (RGCs) are refined to more narrowly localized monolaminar structures characteristic of ON or OFF RGCs. Recently, brain‐derived neurotrophic factor (BDNF) has been shown to regulate this laminar refinement, and to enhance the development of dendritic branches selectively of ON RGCs. Although other related neurotrophins are known to regulate neuronal process formation in the central nervous system, little is known about their action in maturing retina. Here, we report that overexpression of neurotrophin‐3 (NT‐3) in the eye accelerates RGC laminar refinement before eye opening. Furthermore, NT‐3 overexpression increases dendritic branch number but reduces dendritic elongation preferentially in ON‐OFF RGCs, a process that also occurs before eye opening. NT‐3 overexpression does affect dendritic maturation in ON RGCs, but to a much less degree. Taken together, our results suggest that NT‐3 and BDNF exhibit overlapping effects in laminar refinement but distinct RGC‐cell‐type specific effects in shaping dendritic arborization during postnatal development. J. Comp. Neurol. 514:449–458, 2009. © 2009 Wiley‐Liss, Inc.
Efferent projections of thyrotropin‐releasing hormone‐synthesizing neurons residing in the anterior parvocellular subdivision of the hypothalamic paraventricular nucleus
Authors: Wittmann Gábor , Füzesi Tamás , Singru Praful S. , Liposits Zsolt , Lechan Ronald M. , Fekete Csaba
Published: February 2009

The anterior parvocellular subdivision of the PVN (aPVN) contains nonhypophysiotropic thyrotropin‐releasing hormone (TRH) neurons that are densely innervated by feeding‐related neuronal groups of the hypothalamic arcuate nucleus. To determine how these TRH neurons are integrated within the brain, the major projection fields of this cell group were studied by anterograde and retrograde tract‐tracing methods. Projection sites were identified by injection of the anterograde tracerPhaseolus vulgarisleucoagglutinin (PHAL) into the aPVN, and subsequent double immunofluorescent staining was used to visualize axons containing both PHAL and pro‐TRH. To distinguish between the projection sites of TRH neurons residing in the aPVN and the closely situated perifornical area, the retrograde tracer cholera toxin B subunit (CTB) was injected into regions where PHAL/pro‐TRH‐containing axons were densely accumulated. TRH neurons in the aPVN were found to project to the hypothalamic arcuate, dorsomedial and ventral premammillary nuclei, medial preoptic region, tuber cinereum area, paraventricular thalamic nucleus, bed nucleus of the stria terminalis, lateral septal nucleus, and central amygdaloid nucleus. Projection fields of perifornical TRH neurons were in partial overlap with those of the aPVN TRH cells. In addition, these neurons also innervated the hypothalamic ventromedial nucleus, the medial amygdaloid nucleus, and the amygdalohippocampal area. The data suggest that, through its efferent connections, aPVN TRH neurons may be involved in the regulation of energy homeostasis coordinately with effects on behavior, locomotor activity, and thermogenesis. In addition, the major differences in the projection fields of aPVN and perifornical TRH neurons suggest that these two TRH‐synthesizing neuronal groups are functionally different. J. Comp. Neurol. 515:313–330, 2009. © 2009 Wiley‐Liss, Inc.
Altered cutaneous nerve regeneration in a simian immunodeficiency virus / macaque intracutaneous axotomy model
Authors: Ebenezer Gigi J. , Laast Victoria A. , Dearman Brandon , Hauer Peter , Tarwater Patrick M. , Adams Robert J. , Zink M. Christine , McArthur Justin C. , Mankowski Joseph L.
Published: February 2009

To characterize the regenerative pattern of cutaneous nerves in simian immunodeficiency virus (SIV)‐infected and uninfected macaques, excisional axotomies were performed in nonglabrous skin at 14‐day intervals. Samples were examined after immunostaining for the pan‐axonal marker PGP 9.5 and the Schwann cell marker p75 nerve growth factor receptor. Collateral sprouting of axons from adjacent uninjured superficial dermal nerve bundles was the initial response to axotomy. Both horizontal collateral sprouts and dense vertical regeneration of axons from the deeper dermis led to complete, rapid reinnervation of the epidermis at the axotomy site. In contrast to the slower, incomplete reinnervation previously noted in humans after this technique, in both SIV‐infected and uninfected macaques epidermal reinnervation was rapid and completed by 56 days postaxotomy. p75 was densely expressed on the Schwann cells of uninjured nerve bundles along the excision line and on epidermal Schwann cell processes. In both SIV‐infected and uninfected macaques, Schwann cell process density was highest at the earliest timepoints postaxotomy and then declined at a similar rate. However, SIV‐infection delayed epidermal nerve fiber regeneration and remodeling of new sprouts at every timepoint postaxotomy, and SIV‐infected animals consistently had lower mean epidermal Schwann cell densities, suggesting that Schwann cell guidance and support of epidermal nerve fiber regeneration may account for altered nerve regeneration. The relatively rapid regeneration time and the completeness of epidermal reinnervation in this macaque model provides a useful platform for assessing the efficacy of neurotrophic or regenerative drugs for sensory neuropathies including those caused by HIV, diabetes mellitus, medications, and toxins. J. Comp. Neurol. 514:272–283, 2009. © 2009 Wiley‐Liss, Inc.
Erythropoietin receptor expression is concordant with erythropoietin but not with common β chain expression in the rat brain throughout the life span
Authors: Sanchez Pascal E. , Navarro Fabrice P. , Fares Raafat P. , Nadam Jérémie , Georges Béatrice , Moulin Colette , Le Cavorsin Marion , Bonnet Chantal , Ryvlin Philippe , Belmeguenai Amor , Bodennec Jacques , Morales Anne , Bezin Laurent
Published: February 2009

Brain effects of erythropoietin (Epo) are proposed to involve a heteromeric receptor comprising the classical Epo receptor (Epo‐R) and the common β chain (βc). However, data documenting the pattern of βc gene expression in the healthy brain, in comparison with that of the Epo‐R gene, are still lacking. The present study is the first to investigate at the same time βc, Epo‐R, and Epo gene expression within different rat brain areas throughout the life span, from neonatal to elderly stages, using quantitative RT‐PCR for transcripts. Corresponding proteins were localized by using immunohistochemistry. We demonstrate that the βc transcript level does not correlate with that of Epo‐R or Epo, whereas the Epo‐R transcript level strongly correlates with that of Epo throughout the life span in all brain structures analyzed. Both Epo and Epo‐R were detected primarily in neurons. In the hippocampus, the greatest Epo‐R mRNA levels were measured during the early postnatal period and in middle‐aged rats, associated with an intense neuronal immunolabeling. Conversely, βc protein was barely detectable in the brain at all ages, even in neurons expressing high levels of Epo‐R. Finally, βc transcript could not be detected in PC12 cells, even after nerve growth factor‐induced neuritogenesis, which is a condition that dramatically enhances Epo‐R transcript level. Altogether, our data suggest that most neurons are likely to express high levels of Epo‐R but low, if not null, levels of βc. Given that Epo protects extended populations of neurons after injury, a yet‐to‐be‐identified receptor heterocomplex including Epo‐R may exist in the large population of brain neurons that does not express βc. J. Comp. Neurol. 514:403–414, 2009. © 2009 Wiley‐Liss, Inc.
De novo expression of the neurokinin 1 receptor in spinal lamina I pyramidal neurons in polyarthritis
Authors: Almarestani L. , Waters S.M. , Krause J.E. , Bennett G.J. , Ribeiro‐Da‐Silva A.
Published: February 2009

Spinal lamina I (LI) neurons play a major role in the transmission and integration of pain‐related information that is relayed to higher centers. Alterations in the excitability of these neurons influence chronic pain development, and expression of the neurokinin 1 receptor (NK‐1r) is thought to play a major role in such changes. Novel expression of NK‐1r may underlie hyperexcitability in new populations of LI neurons. LI projection neurons can be classified morphologically into fusiform, pyramidal, and multipolar cells, differing in their functional properties, with the pyramidal type being nonnociceptive. In agreement with this, we have shown that spinoparabrachial pyramidal neurons seldom express NK‐1r, in contrast with the other two cell types. In this study we investigated in the rat the long‐term changes in NK‐1r expression by spinoparabrachial LI neurons following the unilateral injection in the hindpaw plantar surface of complete Freund's adjuvant (CFA). Cholera toxin subunit B (CTb) was injected unilaterally into the parabrachial nucleus. Our results revealed that, ipsilaterally, pyramidal neurons were seldom immunoreactive for NK‐1r both in saline‐injected and in CFA‐injected rats, up to 10 days post‐CFA. However, a considerable number of pyramidal cells were immunoreactive for NK‐1r at 15, 21, and 30 days post‐CFA. Our data raise the possibility—which needs to be confirmed by electrophysiology—that most LI projection neurons of the pyramidal type are likely nonnociceptive in naive animals but might become nociceptive following the development of arthritis. J. Comp. Neurol. 514:284–295, 2009. © 2009 Wiley‐Liss, Inc.
Functional remodeling of glutamate receptors by inner retinal neurons occurs from an early stage of retinal degeneration
Authors: Chua Jacqueline , Fletcher Erica L. , Kalloniatis Michael
Published: February 2009

Retinitis pigmentosa reflects a family of diseases that result in retinal photoreceptor death and functional blindness. The natural course of retinal changes secondary to photoreceptor degeneration involves anatomical remodeling (cell process alterations and soma displacement) and neurochemical remodeling. Anatomical remodeling predominantly occurs late in the disease process and cannot explain the significant visual deficits that occur very early in the disease process. Neurochemical remodeling includes modified glutamate receptor disposition and altered responses secondary to functional activation of glutamate receptors. We investigated the neurochemical remodeling of retinal neurons in the rd/rd (rd1) mouse retina by tracking the functional activation of glutamate receptors with a cation probe, agmatine. We provide evidence that bipolar cells and amacrine cells undergo selective remodeling of glutamate receptors during the early phases of retinal degeneration. These early neurochemical changes in the rd/rd mouse retina include the expression of aberrant functional ionotropic glutamate receptors on the cone ON bipolar cells from postnatal day 15 (P15), poor functional activation of metabotropic glutamate receptors on both rod and cone ON bipolar cells throughout development/degeneration, and poor functional activation of N‐methyl‐D‐aspartate receptors on amacrine cells from P15. Our results suggest that major neurochemical remodeling occurs prior to anatomical remodeling, and likely accounts for the early visual deficits in the rd/rd mouse retina. J. Comp. Neurol. 514:473–491, 2009. © 2009 Wiley‐Liss, Inc.
Distribution of EphA5 receptor protein in the developing and adult mouse nervous system
Authors: Cooper Margaret A. , Crockett David P. , Nowakowski Richard S. , Gale Nicholas W. , Zhou Renping
Published: February 2009

The EphA5 receptor tyrosine kinase plays key roles in axon guidance during development. However, the presence of EphA5 protein in the nervous system has not been fully characterized. To examine EphA5 localization better, mutant mice, in which the EphA5 cytoplasmic domain was replaced with β‐galactosidase, were analyzed for both temporal and regional changes in the distribution of EphA5 protein in the developing and adult nervous system. During embryonic development, high levels of EphA5 protein were found in the retina, olfactory bulb, cerebral neocortex, hippocampus, pretectum, tectum, cranial nerve nuclei, and spinal cord. Variations in intensity were observed as development proceeded. Staining of pretectal nuclei, tectal nuclei, and other areas of the mesencephalon became more diffuse after maturity, whereas the cerebral neocortex gained more robust intensity. In the adult, receptor protein continued to be detected in many areas including the olfactory nuclei, neocortex, piriform cortex, induseum griseum, hippocampus, thalamus, amygdala, hypothalamus, and septum. In addition, EphA5 protein was found in the claustrum, stria terminalis, barrel cortex, and striatal patches, and along discrete axon tracts within the corpus callosum of the adult. We conclude that EphA5 function is not limited to the developing mouse brain and may play a role in synaptic plasticity in the adult. J. Comp. Neurol. 514:310–328, 2009. © 2009 Wiley‐Liss, Inc.
The Potential of Supported Cu2O and CuO Nanosystems in Photocatalytic H2 Production
Authors: Barreca Davide , Fornasiero Paolo , Gasparotto Alberto , Gombac Valentina , Maccato Chiara , Montini Tiziano , Tondello Eugenio
Published: February 2009

Hy wire: Supported Cu2O nanosystems and CuO nanowires obtained by chemical vapor deposition were used in the photocatalytic splitting of methanol/water solutions to produce hydrogen. The results obtained with these systems open appealing perspectives for the clean conversion of sunlight into storable chemical energy.

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Brainstem mechanisms underlying the sudden infant death syndrome: Evidence from human pathologic studies
Authors: Kinney Hannah C.
Published: February 2009

The brainstem hypothesis is one of the leading hypotheses concerning the sudden infant death syndrome (SIDS). It states that SIDS, or an important subset of SIDS, is due to abnormal brainstem mechanisms in the control of respiration, chemosensitivity, autonomic regulation, and/or arousal which impairs the infant's response to life‐threatening, but often occurring, stressors during sleep (e.g., hypoxia, hypercarbia, asphyxia, hyperthermia) and leads to sudden death in a vulnerable developmental period. In this review, we summarize neuropathologic evidence from SIDS cases that support this hypothesis, beginning with the seminal report of subtle brainstem gliosis three decades ago. We focus upon recent neurochemical studies in our laboratory concerning the neurotransmitter serotonin (5‐HT) and its key role in mediating protective responses to homeostatic stressors via medullary circuits. The possible fetal origin of brainstem defects in SIDS is reviewed, including evidence for adverse effects of prenatal exposure to maternal cigarette smoking and alcohol upon the postnatal development of human brainstem 5‐HT pathways. © 2009 Wiley Periodicals, Inc. Dev Psychobiol 51: 223–233, 2009
MicroCT for developmental biology: A versatile tool for high‐contrast 3D imaging at histological resolutions
Authors: Metscher Brian D.
Published: February 2009

Understanding developmental processes requires accurate visualization and parameterization of three‐dimensional embryos. Tomographic imaging methods offer automatically aligned and calibrated volumetric images, but the usefulness of X‐ray CT imaging for developmental biology has been limited by the low inherent contrast of embryonic tissues. Here, I demonstrate simple staining methods that allow high‐contrast imaging of embryonic tissues at histological resolutions using a commercial microCT system. Quantitative comparisons of images of chick embryos treated with different contrast agents show that three very simple methods using inorganic iodine and phosphotungstic acid produce overall contrast and differential tissue contrast for X‐ray imaging at least as high as that obtained with osmium. The stains can be used after any common fixation and after storage in aqueous or alcoholic media, and on a wide variety of species. These methods establish microCT imaging as a useful tool for comparative developmental studies, embryo phenotyping, and quantitative modeling of development. Developmental Dynamics 238:632–640, 2009. © 2009 Wiley‐Liss, Inc.
Cell adhesion molecule L1 affects the rate of differentiation of enteric neurons in the developing gut
Authors: Turner Kirsty N. , Schachner Melitta , Anderson Richard B.
Published: February 2009

The enteric nervous system arises predominantly from vagal level neural crest cells that migrate into and along the developing gut. As the neural crest‐derived cells migrate within the gut, a subpopulation begins to differentiate into enteric neurons. Here, we show that the differentiation of neural crest‐derived cells into enteric neurons is delayed in L1‐deficient mice, compared with littermate controls. However, glial cell differentiation is not affected in L1‐deficient mice. These mice also show a delay in the differentiation of a neurotransmitter‐specific subtype of enteric neuron within the gastrointestinal tract. Together, these results suggest a role for the cell adhesion molecule, L1, in the differentiation of neural crest‐derived cells into enteric neurons within the developing enteric nervous system. Developmental Dynamics 238:708–715, 2009. © 2009 Wiley‐Liss, Inc.
Tubulin polymerization‐promoting protein family member 3, Tppp3, is a specific marker of the differentiating tendon sheath and synovial joints
Authors: Staverosky Julia A. , Pryce Brian A. , Watson Spencer S. , Schweitzer Ronen
Published: February 2009

Tppp3, a member of the Tubulin polymerization‐promoting protein family, is an intrinsically unstructured protein that induces tubulin polymerization. We show that Tppp3 is a distinct marker in the developing musculoskeletal system. In tendons, Tppp3 is expressed in cells at the circumference of the developing tendons, likely the progenitors of connective tissues that surround tendons: the tendon sheath, epitenon, and paratenon. These tissues form an elastic sleeve around tendons and provide lubrication to minimize friction between tendons and surrounding tissues. Tppp3 is the first molecular marker of the tendon sheath, opening the door for direct examination of these tissues. Tppp3 is also expressed in forming synovial joints. The onset of Tppp3 expression in joints coincides with cavitation, representing a molecular marker that can be used to indicate this stage in joint transition in joint differentiation. In late embryonic stages, Tppp3 expression highlights other demarcation lines that surround differentiating tissues in the forelimb. Developmental Dynamics 238:685–692, 2009. © 2009 Wiley‐Liss, Inc.
Mouse mutagenesis identifies novel roles for left–right patterning genes in pulmonary, craniofacial, ocular, and limb development
Authors: Ermakov Alexander , Stevens Jonathan L. , Whitehill Elaine , Robson Joan E. , Pieles Guido , Brooker Debra , Goggolidou Paraskevi , Powles‐Glover Nicola , Hacker Terry , Young Stephen R. , Dear Neil , Hirst Elizabeth , Tymowska‐Lalanne Zuzanna , Briscoe James , Bhattacharya Shoumo , Norris Dominic P.
Published: February 2009

Vertebrate organs show consistent left–right (L‐R) asymmetry in placement and patterning. To identify genes involved in this process we performed an ENU‐based genetic screen. Of 135 lines analyzed 11 showed clear single gene defects affecting L‐R patterning, including 3 new alleles of known L‐R genes and mutants in novel L‐R loci. We identified six lines (termed “gasping”) that, in addition to abnormal L‐R patterning and associated cardiovascular defects, had complex phenotypes including pulmonary agenesis, exencephaly, polydactyly, ocular and craniofacial malformations. These complex abnormalities are present in certain human disease syndromes (e.g., HYLS, SRPS, VACTERL). Gasping embryos also show defects in ciliogenesis, suggesting a role for cilia in these human congenital malformation syndromes. Our results indicate that genes controlling ciliogenesis and left–right asymmetry have, in addition to their known roles in cardiac patterning, major and unexpected roles in pulmonary, craniofacial, ocular and limb development with implications for human congenital malformation syndromes. Developmental Dynamics 238:581–594, 2009. © 2009 Wiley‐Liss, Inc.
Role for notch signaling in salivary acinar cell growth and differentiation
Authors: Dang Howard , Lin Alan L. , Zhang Binxian , Zhang Hong‐Mei , Katz Michael S. , Yeh Chih‐Ko
Published: February 2009

The Notch pathway is crucial for stem/progenitor cell maintenance, growth and differentiation in a variety of tissues. The Notch signaling is essential for Drosophila salivary gland development but its role in mammalian salivary gland remains unclear. The human salivary epithelial cell line, HSG, was studied to determine the role of Notch signaling in salivary epithelial cell differentiation. HSG expressed Notch 1 to 4, and the Notch ligands Jagged 1 and 2 and Delta 1. Treatment of HSG cells with inhibitors of γ‐secretase, which is required for Notch cleavage and activation, blocked vimentin and cystatin S expression, an indicator of HSG differentiation. HSG differentiation was also associated with Notch downstream signal Hes‐1 expression, and Hes‐1 expression was inhibited by γ‐secretase inhibitors. siRNA corresponding to Notch 1 to 4 was used to show that silencing of all four Notch receptors was required to inhibit HSG differentiation. Normal human submandibular gland expressed Notch 1 to 4, Jagged 1 and 2, and Delta 1, with nuclear localization indicating Notch signaling in vivo. Hes‐1 was also expressed in the human tissue, with staining predominantly in the ductal cells. In salivary tissue from rats undergoing and recovering from ductal obstruction, we found that Notch receptors and ligands were expressed in the nucleus of the regenerating epithelial cells. Taken together, these data suggest that Notch signaling is critical for normal salivary gland cell growth and differentiation. Developmental Dynamics 238:724–731, 2009. © 2009 Wiley‐Liss, Inc.
Synectin‐dependent regulation of arterial maturation
Authors: Paye Julie M.D. , Phng Li‐Kun , Lanahan Anthony A. , Gerhard Holger , Simons Michael
Published: February 2009

Synectin, a ubiquitously expressed PDZ scaffold protein, has been shown to be a key regulator in the formation of arterial vasculature. Examination of the retinal vasculature in synectin−/− mice demonstrated poor mural cell coverage of and attachment to the forming arterial tree, a defect reminiscent of retinal abnormalities observed in platelet derived growth factor (PDGF) ‐B−/− mice. Primary cultures of synectin−/− smooth muscle cells had normal expression of PDGFR‐β and migrated normally in response to PDGF‐BB. However, expression of PDGF‐BB protein, but not mRNA, was reduced in lysates from arterial, but not venous, primary synectin−/− endothelial cells (EC), that was restored by inhibition of proteosomal degradation. Transduction of synectin−/− and +/+ EC with a bicistronic Pdgfb/gfp construct, resulted in comparable expression of green fluorescent protein in both EC populations while PDGF‐BB expression was severely reduced in synectin−/− EC. Finally, synectin expression in synectin−/− arterial EC restored PDGF‐BB protein levels. These results suggest that synectin deficiency results in increased degradation of PDGF‐BB protein in arterial EC and, consequently, reduced recruitment of mural cells to newly forming arteries. This observation may explain the selective reduction in arterial morphogenesis observed in synectin knockout mice. Developmental Dynamics 238:604–610, 2009. © 2009 Wiley‐Liss, Inc.
Targeted deletion of Nm23/nucleoside diphosphate kinase A and B reveals their requirement for definitive erythropoiesis in the mouse embryo
Authors: Postel Edith H. , Wohlman Irene , Zou Xiaoming , Juan Todd , Sun Ning , D'Agostin Diane , Cuellar Maria , Choi Theresa , Notterman Daniel A. , La Perle Krista M.D.
Published: February 2009

The ubiquitously expressed nucleoside diphosphate kinases (Nm23/NDPK/Awd) are a large family of multifunctional enzymes implicated in nucleic acid metabolism and in normal and abnormal development. Here, we describe the generation and characterization of NDPK A‐ and B‐deficient (Nme1−/−/Nme2−/−) mice in which >95% of the enzyme activity is eliminated. These mice are undersized, die perinatally, and exhibit a spectrum of hematological phenotypes including severe anemia, impaired maturation of erythrocytes, and abnormal hematopoiesis in the liver and bone marrow. Flow cytometric analysis of developing Nme1−/−/Nme2−/− erythroid cells indicated that the major iron transport receptor molecule TfR1 is attenuated concomitant with a reduction of intracellular iron, suggesting that TfR1 is a downstream target of NDPKs and that reduced iron in Nme1−/−/Nme2−/− erythroblasts is inhibiting their development. We conclude that Nm23/NDPKs play critical roles in definitive erythroid development. Our novel mouse model also links erythropoiesis and nucleotide metabolism. Developmental Dynamics 238:775–787, 2009. © 2009 Wiley‐Liss, Inc.
Remodeling of aortic smooth muscle during avian embryonic development
Authors: Wiegreffe Christoph , Christ Bodo , Huang Ruijin , Scaal Martin
Published: February 2009

The dorsal aorta is the earliest formed intraembryonic blood vessel in vertebrates composed of an inner lining of endothelial cells (ECs) and a slightly later‐forming outer wall consisting of vascular smooth muscle cells (SMCs) and pericytes. We previously identified the sclerotome as the only somitic compartment contributing to aortic SMCs in the trunk of the avian embryo. However, we demonstrated that the first SMCs in the aortic floor are not of somitic origin and must be derived from a different source. Here, we show that the primary SMCs are a transient population of aortic wall cells originating from the splanchnic mesoderm. A model is presented suggesting that wall formation of the early dorsal aorta in chick is a two‐step process: The primary, transient SMCs in the aortic floor originate in the splanchnic mesoderm, whereas the secondary, definitive SMCs of the entire aortic wall originate in the sclerotome. Developmental Dynamics 238:624–631, 2009. © 2009 Wiley‐Liss, Inc.
Two Hoxc6 transcripts are differentially expressed and regulate primary neurogenesis in Xenopus laevis
Authors: Bardine Nabila , Donow Cornelia , Korte Brigitte , Durston Antony J. , Knöchel Walter , Wacker Stephan A.
Published: February 2009

Hox genes are key players in defining positional information along the main body axis of vertebrate embryos. In Xenopus laevis, Hoxc6 was the first homeobox gene isolated. It encodes two isoforms. We analyzed in detail their spatial and temporal expression pattern during early development. One major expression domain of both isoforms is the spinal cord portion of the neural tube. Within the spinal cord and its populations of primary neurons, Hox genes have been found to play a crucial role for defining positional information. Here we report that a loss‐of‐function of either one of the Hoxc6 products does not affect neural induction, the expression of general neural markers is not modified. However, Hoxc6 does widely affect the formation of primary neurons within the developing neural tissue. Manipulations of Hoxc6 expression severly changes the expression of the neuronal markers N‐tubulin and Islet‐1. Formation of primary neurons and formation of cranial nerves are affected. Hence, Hoxc6 functions are not restricted to the expected role in anterior‐posterior pattern formation, but they also regulate N‐tubulin, thereby having an effect on the initial formation of primary neurons in Xenopus laevis embryos. Developmental Dynamics 238:755–765, 2009. © 2009 Wiley‐Liss, Inc.
Automated image‐based phenotypic analysis in zebrafish embryos
Authors: Vogt Andreas , Cholewinski Andrzej , Shen Xiaoqiang , Nelson Scott G. , Lazo John S. , Tsang Michael , Hukriede Neil A.
Published: February 2009

Presently, the zebrafish is the only vertebrate model compatible with contemporary paradigms of drug discovery. Zebrafish embryos are amenable to automation necessary for high‐throughput chemical screens, and optical transparency makes them potentially suited for image‐based screening. However, the lack of tools for automated analysis of complex images presents an obstacle to using the zebrafish as a high‐throughput screening model. We have developed an automated system for imaging and analyzing zebrafish embryos in multi‐well plates regardless of embryo orientation and without user intervention. Images of fluorescent embryos were acquired on a high‐content reader and analyzed using an artificial intelligence‐based image analysis method termed Cognition Network Technology (CNT). CNT reliably detected transgenic fluorescent embryos (Tg(fli1:EGFP)y1) arrayed in 96‐well plates and quantified intersegmental blood vessel development in embryos treated with small molecule inhibitors of anigiogenesis. The results demonstrate it is feasible to adapt image‐based high‐content screening methodology to measure complex whole organism phenotypes. Developmental Dynamics 238:656–663, 2009. © 2009 Wiley‐Liss, Inc.
Tracking gene expression during zebrafish osteoblast differentiation
Authors: Li Nan , Felber Katharina , Elks Phil , Croucher Peter , Roehl Henry H.
Published: February 2009

Expression of collagen10a1 marks the formation of both dermal and cartilage bones in five day old zebrafish (ventral view). See Li et al., Developmental Dynamics 238:459–66, 2009. © 2009 Wiley‐Liss, Inc.
A transgenic mouse that reveals cell shape and arrangement during ureteric bud branching
Authors: Chi Xuan , Hadjantonakis Anna‐Katerina , Wu Zaiqi , Hyink Deborah , Costantini Frank
Published: February 2009

3‐D images showing the outlines of individual cells in the ureteric bud tips of a Hoxb7/myr‐Venus transgenic mouse kidney at embryonic day 15.5. Image stacks were acquired with a Bio‐Rad laser scanning confocal microscope equipped with an Olympus U PlanApo/IR water lens 60x /NA1.2. The images were processed using blind deconvolution (AutoDeblur, Media Cybernetics, Bethesda, MD), followed by volume rendering (Volocity software). See the article by Chi et al. in this issue.
Asymmetric Synthesis of Aminocyclopropanes and N‐Cyclopropylamino Alcohols Through Direct Amidocyclopropanation of Alkenes Using Chiral Organozinc Carbenoids
Authors: Bégis Guillaume , Cladingboel David E. , Jerome Laure , Motherwell William B. , Sheppard Tom D.
Published: February 2009

Chiral N‐(diethoxymethyl)oxazolidinones, prepared from the corresponding oxazolidinones by heating in triethyl orthoformate, can be used as organozinc carbenoid precursors for the direct enantioselective amidocyclopropanation of alkenes. The reaction is successful with a wide range of oxazolidinones and alkenes and proceeds with moderate to excellent yield and stereoselectivity. In most cases the trans/exo amidocyclopropane product is favoured, although certain cyclicalkenes such as indene favour the formation of the endo cyclopropane. The products can be readily elaborated to produce cyclopropylamino alcohols and amino acids.(© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
A Tetrakis(tetrazolyl) Analogue of EDTA
Authors: Touti Faycal , Maurin Philippe , Hasserodt Jens
Published: February 2009

The tetrazole moiety is usually established in situ with the corresponding inconveniences, such as reactant incompatibility, yield. In most of these cases, the tetrazole is formed in its nonprotected form. Subsequent protection is unattractive because of the promiscuous formation of two regioisomers. No particular protecting group has seen widespread use. The growing field of site‐selective oxidation of unactivated hydrocarbons makes use of metal complexes based on multidentate ligands displaying nitrogen coordination sites. We have characterized an easily accessible, benzyl‐protected synthon that allows the convergent introduction of the tetrazolylmethyl moiety and its smooth deprotection by catalytic hydrogenation. With the straightforward synthesis of the new hexadentate ligand EDTT, we have demonstrated the utility of this synthon for the fields of coordination, medicinal, and organocatalytic chemistry. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)
Preparation and Characterization of a Tin Pentacyanonitrosylferrate‐Modified Carbon Ceramic Electrode: Application to Electrocatalytic Oxidation and Amperometric Detection of L‐Cysteine
Authors: Razmi H. , Habibi Es.
Published: February 2009

The sol‐gel technique was used to construct tin pentacyanonitrosylferrate (SnPCNF) modified composite carbon ceramic electrode (CCE). This involves two steps: construction of CCE containing metallic Sn powder and then electrochemical creating of SnPCNF on the surface of CCE. The SnPCNF modified CCE (SnPCNFlCCE) was characterized by energy‐dispersive X‐ray (EDX), FTIR and cyclic voltammetry (CV) techniques. The SnPCNF film showed electrocatalytic activity toward the oxidation of L‐cysteine. A linear calibration plot was obtained over the L‐cysteine concentration range 1–51 μM using chronoamperometry. L‐cysteine was determined amperometrically at the surface of this modified electrode. The detection limit (for a signal to noise of 3) and sensitivity were found to be 0.62 μM and 126 μA/mM, respectively.
Novel Amperometric Sensor Based on Rigid Near‐Percolation Composite
Authors: Olivé‐Monllau Rosa , Baeza Mireia , Bartrolí Jordi , Céspedes Francisco
Published: February 2009

A novel amperometric sensor based on a rigid graphite‐epoxy composite of which composition is near to the percolation is reported. The electrochemical response of the novel transducer material was evaluated in terms of reproducibility of the fabrication process and reproducibility and repeatability of the analytical signal. The signal to noise ratio was improved. atomic force microscopy (AFM) technique was used to obtain qualitatively information. Amperometric detection of chlorine in water was carried on at a set potential of −250 mV vs. Ag/AgCl. The developed flow injection analysis (FIA) system responded linearly to chlorine concentration between 0.15 mg L−1 and 4 mg L−1with a sensitivity of −0.20 μA L mg−1. The proposed system was applied to real samples from swimming‐pool water. No significant difference was observed regarding the standard method.
Electrocatalytic Behavior and Amperometric Detection of Morphine on ITO Electrode Modified with Directly Electrodeposited Gold Nanoparticles
Authors: Zhao Yanrong , Wu Ying , Zhang Yu , Chen Zeguan , Cao Xia , Di Junwei , Yang Jianping
Published: February 2009

A gold nanoparticles (AuNPs) modified indium tin oxide (ITO) film coated glass electrode was prepared via a novel electrochemical deposition technique. The UV‐visible spectrum and SEM indicated that the AuNPs on ITO electrode surface were spherical shape and quite symmetric distributed. The modified electrode exhibited excellent catalytic activity for the oxidation of morphine (MO). At optimal experimental condition, the oxidation current was responsive with the MO concentrations ranging from 8.0×10−7 to 1.6×10−5 M, the detection limit was 2.1×10 –7 M. The modified electrode also exhibited high stability and reproducibility. The average recoveries of detection MO in human urine were ranged between 91.95% and 92.23%, and the RSD was less than 3.68% (n=5).