bluuebunny/crossref_metadata_2025_split huggingface dataset:
Genetic richness of vibriophages isolated in a coastal environment
Authors: Comeau André M. , Chan Amy M. , Suttle Curtis A. 
Published: March 2006

SummaryThe purpose of this study was to characterize Vibrio parahaemolyticus viruses (VpVs) isolated from different environments within and adjacent to the Strait of Georgia, and to examine the relative influences of distance and environment on host‐range and genetic richness. Nearly all seawater enrichment cultures (29/31) generated isolates, implying that VpVs were widespread in the virioplankton, yet at low abundances (< 1 l−1). Viruses were not detected in sediments (n = 99). Fourteen of the 16 viruses characterized were siphoviruses, with genome sizes ranging from ∼45–106 kb, and half were capable of infecting other Vibrio species. The VpVs infected bacteria isolated from oysters and sediments fairly well (55% and 46% of the host‐virus combinations, respectively), but were unable to infect many of the bacteria isolated from the water column (< 13% of 112 combinations). When compared with VpVs from oysters, it was clear that the major determinant of phenotypic (host‐range) and genetic richness (by the DP‐RAPD assay) was not geography, but the source environment from which the VpVs originated. Therefore, the VpV population within the Strait of Georgia is a highly diverse mixture of phenotypes and genotypes.
An in‐built proteinase inhibitor system for the protection of recombinant proteins recovered from transgenic plants
Authors: Rivard Daniel , Anguenot Raphaël , Brunelle France , Le Van Quy , Vézina Louis‐Philippe , Trépanier Sonia , Michaud Dominique 
Published: March 2006

SummaryProteolytic degradation represents a significant barrier to the efficient production of several recombinant proteins in plants, bothin vivoduring their expression andin vitroduring their recovery from source tissues. Here, we describe a strategy to protect recombinant proteins during the recovery process, based on the coexpression of a heterologous proteinase inhibitor acting as a ‘mouse trap’ against the host proteases during extraction. After confirming the importance of trypsin‐ and chymotrypsin‐like activities in crude protein extracts of potato (Solanum tuberosumL.) leaves, transgenic lines of potato expressing either tomato cathepsin D inhibitor (CDI) or bovine aprotinin, both active against trypsin and chymotrypsin, were generated byAgrobacterium tumefaciens‐mediated genetic transformation. Leaf crude protein extracts from CDI‐expressing lines, showing decreased levels of cathepsin D‐like and ribulose 1,5‐bisphosphate carboxylase/oxygenase hydrolysing activitiesin vitro, conducted decreased turnover rates of the selection marker protein neomycin phosphotransferase II (NPTII) relative to the turnover rates measured for transgenic lines expressing only the marker protein. A similar stabilizing effect on NPTII was observed in leaf protein extracts from plant lines coexpressing bovine aprotinin, confirming the ability of ectopically expressed broad‐spectrum serine proteinase inhibitors to reproduce the protein‐stabilizing effect of low‐molecular‐weight proteinase inhibitors generally added to protein extraction media.
Meaningful Acts: Terrorists, Artists, and States
Authors: Torres Sonia 
Published: March 2006

Terrorism is not a novelty. As Chomsky points out, the term came into use at the end of the eighteenth century, and referred to violent acts of governments with the intent to ensure popular submission. One need only remember the reign of terror, whose social cement was force and cruelty, in which the Illu‐minist ideals of the French Revolution seemed to have been defeated. In con‐temporary Western societies, terrorism has come to be associated mainly with what Chomsky calls “retail terrorism,” by individuals or groups (as opposed to the “wholesale terrorism” of governments).1 What are the different forms of conceiving the term, in the last quarter of a century? The following dictionary entries on terror/terrorism, as well as the most recurrent definitions provided by terrorism scholars and state institutions, are worthy of highlighting:
Terrorism: System of governing through terror, or by means of violent revolutions.2Terrorism: 1. Means of coercing, threatening, or influencing other people, or of imposing a will upon them through the systematic deployment of terror; 2. form of political action that combats the established power by violent means.3Terrorism: 1. The act of terrorizing; use of force or threat to demoralize, intimidate, and subjugate, esp. such use as a political weapon or policy; 2. the demoralization and intimidation produced in this way. Syn. Disorder; lawlessness; murder; nihilism.4The unlawful use of force or violence against persons or property to intimidate or coerce a government, the civilian population, or any segment thereof, in furtherance of political or social objectives. (FBI)5Premeditated, politically motivated violence perpetuated against noncombatant targets by subnational groups or clandestine agents, usually intended to influence an audience. (U.S. Department of State)6Terrorism is a symbolic act designed to influence political behavior by extranormal means, entailing the use or threat of violence.7Terrorism, in the most widely accepted contemporary usage of the term, is fundamentally and inherently political. It is also ineluctably about power: the pursuit of power, the acquisition of power, and the use of power to achieve political change.8
Canalization and developmental stability in the Brachyrrhine mouse
Authors: Willmore Katherine Elizabeth , Zelditch Miriam Leah , Young Nathan , Ah‐Seng Andrew , Lozanoff Scott , Hallgrímsson Benedikt 
Published: March 2006

AbstractThe semi‐dominantBrmutation affects presphenoid growth, producing the facial retrognathism and globular neurocranial vault that characterize heterozygotes. We analysed the impact of this mutation on skull shape, comparing heterozygotes to wildtype mice, to determine if the effects are skull‐wide or confined to the sphenoid region targeted by the mutation. In addition, we examined patterns of variability of shape for the skull as a whole and for three regions (basicranium, face and neurocranium). We found that theBrmice differed significantly from wildtype mice in skull shape in all three regions as well as in the shape of the skull as a whole. However, the significant increases in variance and fluctuating asymmetry were found only in the basicranium of mutant mice. These results suggest that the mutation has a significant effect on the underlying developmental architecture of the skull, which produces an increase in phenotypic variability that is localized to the anatomical region in which the mean phenotype is most dramatically affected. These results suggest that the same developmental mechanisms that produce the change in phenotypic mean also produce the change in variance.
Effects of increased nerve growth factor plasma levels on the expression of TrkA and p75NTRin rat testicles
Authors: Levanti M. B. , Germanà A. , de Carlos F. , Ciriaco E. , Vega J. A. , Germanà G. 
Published: March 2006

AbstractIn addition to their well‐known roles within the nervous system, the neurotrophins and their receptors regulate some functions in the reproductive system. In this study we used combined morphological and immunohistochemical techniques to investigate the presence and cellular localization in the rat testicle of the two receptors of nerve growth factor (NGF), i.e. TrkA and p75NTR. Furthermore, to evaluate whether increased plasma levels of NGF affect the ageing process, 4‐methylcathechol (4‐MC), an inductor of NGF synthesis, was administered. Both TrkA and p75NTRwere expressed in rat testicles, but the pattern and intensity of immunoreaction were marginally different between them. In adult rats TrkA was expressed in spermatozoa and spermatids, and p75 was expressed in spermatogonia. In newborn rats TrkA immunoreactivity was found in the Leydig cells, whereas p75 was detected in a cellular layer that surrounds the seminiferous tubules. In adult treated animals the immunoreaction for TrkA and p75NTRwas also localized in the spermatocytes, whereas in newborn treated rats no changes in the pattern of immunoreaction was observed. The present findings suggest a role of the NGF/TrkA/p75 system in the physiology of reproduction, but the practical relevance of this remains to be established.
The functional anatomy of the iliotibial band during flexion and extension of the knee: implications for understanding iliotibial band syndrome
Authors: Fairclough John , Hayashi Koji , Toumi Hechmi , Lyons Kathleen , Bydder Graeme , Phillips Nicola , Best Thomas M. , Benjamin Mike 
Published: March 2006

AbstractIliotibial band (ITB) syndrome is a common overuse injury in runners and cyclists. It is regarded as a friction syndrome where the ITB rubs against (and ‘rolls over’) the lateral femoral epicondyle. Here, we re‐evaluate the clinical anatomy of the region to challenge the view that the ITB moves antero‐posteriorly over the epicondyle. Gross anatomical and microscopical studies were conducted on the distal portion of the ITB in 15 cadavers. This was complemented by magnetic resonance (MR) imaging of six asymptomatic volunteers and studies of two athletes with acute ITB syndrome. In all cadavers, the ITB was anchored to the distal femur by fibrous strands, associated with a layer of richly innervated and vascularized fat. In no cadaver, volunteer or patient was a bursa seen. The MR scans showed that the ITB was compressed against the epicondyle at 30° of knee flexion as a consequence of tibial internal rotation, but moved laterally in extension. MR signal changes in the patients with ITB syndrome were present in the region occupied by fat, deep to the ITB. The ITB is prevented from rolling over the epicondyle by its femoral anchorage and because it is a part of the fascia lata. We suggest that it creates the illusion of movement, because of changing tension in its anterior and posterior fibres during knee flexion. Thus, on anatomical grounds, ITB overuse injuries may be more likely to be associated with fat compression beneath the tract, rather than with repetitive friction as the knee flexes and extends.
Structural and functional anatomy of the neck musculature of the dog (Canis familiaris)
Authors: Sharir Amnon , Milgram Joshua , Shahar Ron 
Published: March 2006

AbstractThe morphometric properties and the anatomical relationships of the entire musculature of the canine cervical spine are reported herein. These data were obtained from the dissection of cadavers of six dogs. Total muscle length, muscle weight, fascicle length and angles of pennation were recorded for each muscle comprising the canine cervical spine. Based upon these properties, physiological cross‐section area (PCSA) and architectural index were estimated. When scaled by whole body mass, the values of each of these parameters were found to be similar between all dogs. Muscles that course from the cranial neck to the shoulder girdle or the rib cage (e.g. brachiocephalicus and rhomboideus capitis) were found to have relatively long fascicles and low PCSA values and thus appear to be designed for rapid excursions. By contrast, muscles that primarily support the neck and shoulder against gravitational forces (e.g. serratus ventralis and trapezius) were found to have relatively high PCSA values and short fascicle lengths, and thus have the capacity to generate large forces. Differences of morphometry as well as nomenclature were found between the canine and human neck musculature. Nevertheless, many similarities exist; in particular, both species have similar muscles adapted to force generation or large excursions. We thus conclude that the canine neck may be used as a modelling tool for biomechanical investigations of the human cervical region as long as the differences listed are borne in mind.
Insight into the evolution of avian flight from a new clade of Early Cretaceous ornithurines from China and the morphology of Yixianornis grabaui
Authors: Clarke Julia A. , Zhou Zhonghe , Zhang Fucheng 
Published: March 2006

AbstractIn studies of the evolution of avian flight there has been a singular preoccupation with unravelling its origin. By contrast, the complex changes in morphology that occurred between the earliest form of avian flapping flight and the emergence of the flight capabilities of extant birds remain comparatively little explored. Any such work has been limited by a comparative paucity of fossils illuminating bird evolution near the origin of the clade of extant (i.e. ‘modern’) birds (Aves). Here we recognize three species from the Early Cretaceous of China as comprising a new lineage of basal ornithurine birds. Ornithurae is a clade that includes, approximately, comparatively close relatives of crown clade Aves (extant birds) and that crown clade. The morphology of the best‐preserved specimen from this newly recognized Asian diversity, the holotype specimen of Yixianornis grabaui Zhou and Zhang 2001, complete with finely preserved wing and tail feather impressions, is used to illustrate the new insights offered by recognition of this lineage. Hypotheses of avian morphological evolution and specifically proposed patterns of change in different avian locomotor modules after the origin of flight are impacted by recognition of the new lineage. The complete articulated holotype specimen of Yixianornis grabaui, from the Early Cretaceous Jiufotang Formation of Liaoning Province, in north‐eastern China, arguably the best‐preserved basal ornithurine specimen yet discovered, provides the earliest evidence consistent with the presence of extant avian tail feather fanning.
Homology of the reptilian coracoid and a reappraisal of the evolution and development of the amniote pectoral apparatus
Authors: Vickaryous Matthew K. , Hall Brian K. 
Published: March 2006

AbstractAs in monotreme mammals, the pectoral apparatus of basal (fossil) amniotes includes two coracoid elements, the procoracoid and metacoracoid. Among extant reptiles the metacoracoid has long been assumed lost; this notion is herein challenged. A comprehensive review of data from numerous sources, including the fossil record, experimental embryology, genetic manipulations and an analysis of morphology at the level cell condensations, supports the conclusion that the metacoracoid gives rise to the majority of the reptilian coracoid. By contrast, the reptilian procoracoid remains as a rudiment that is incorporated as a process of the (meta)coracoid and/or the glenoid region of the scapula early during development, prior to skeletogenesis. Application of this integrated approach corroborates and enhances previous work describing the evolution of the pectoral apparatus in mammals. A revised scenario of amniote coracoid evolution is presented emphasizing the importance of considering cell condensations when evaluating the homology of a skeletal complex.
Oestrogen receptor subtype‐specific repression of calpain expression and calpain enzymatic activity in neuronal cells – implications for neuroprotection against Ca2+‐mediated excitotoxicity
Authors: Gamerdinger Martin , Manthey Dieter , Behl Christian 
Published: March 2006

AbstractCalpains represent a superfamily of Ca2+‐activated cysteine‐proteases, which are important mediators of apoptosis and necrosis. In the brain, m‐calpain and µ‐calpain, the two ubiquitous calpain‐isoforms, are strongly activated in neurones after an excitotoxic Ca2+ influx occurring, for example, during cerebral ischemia. Because oestrogen and its receptors (ERα/ERβ) can exert neuroprotective activity, we investigated their influence on expression of calpains and their endogenous inhibitor, calpastatin. We found that ectopic expression of ERα in human neuroblastoma SK‐N‐MC cells led to a ligand‐independent constitutive down‐regulation of m‐calpain accompanied by an up‐regulation of µ‐calpain expression. Up‐regulation of µ‐calpain was reversed in the presence of oestrogen, which, in turn, could be blocked by co‐treatment with the oestrogen‐receptor antagonist ICI 182 780. Expression of calpastatin was not altered, either in the absence or in the presence of oestrogen. Additional studies revealed that ERα‐expressing cells exhibited decreased calpain enzymatic activity and increased survival when cells were exposed to the Ca2+ ionophore, ionomycin. Since all investigated effects could be observed exclusively in the presence of ERα, but not ERβ, and since the effects are reduced when ERα and ERβ are co‐expressed, our data suggest a novel ER subtype‐specific neuroprotective action by repressing calpain expression and calpain activity under conditions of a massive Ca2+ influx.
The “ins” and “outs” of the high‐affinity choline transporter CHT1
Authors: Ribeiro Fabiola M. , Black Stefanie A. G. , Prado Vania F. , Rylett R. Jane , Ferguson Stephen S. G. , Prado Marco A. M. 
Published: March 2006

AbstractMaintenance of acetylcholine (ACh) synthesis depends on the activity of the high‐affinity choline transporter (CHT1), which is responsible for the reuptake of choline from the synaptic cleft into presynaptic neurons. In this review, we discuss the current understanding of mechanisms involved in the cellular trafficking of CHT1. CHT1 protein is mainly found in intracellular organelles, such as endosomal compartments and synaptic vesicles. The presence of CHT1 at the plasma membrane is limited by rapid endocytosis of the transporter in clathrin‐coated pits in a mechanism dependent on a dileucine‐like motif present in the carboxyl‐terminal region of the transporter. The intracellular pool of CHT1 appears to constitute a reserve pool of transporters, important for maintenance of cholinergic neurotransmission. However, the physiological basis of the presence of CHT1 in intracellular organelles is not fully understood. Current knowledge about CHT1 indicates that stimulated and constitutive exocytosis, in addition to endocytosis, will have major consequences for regulating choline uptake. Future investigations of CHT1 trafficking should elucidate such regulatory mechanisms, which may aid in understanding the pathophysiology of diseases that affect cholinergic neurons, such as Alzheimer's disease.
Specific regulation of rat glial cell line‐derived neurotrophic factor gene expression by riluzole in C6 glioma cells
Authors: Caumont Anne‐Sophie , Octave Jean‐Noël , Hermans Emmanuel 
Published: March 2006

AbstractContrasting with its robust expression during embryogenesis, the glial cell line‐derived neurotrophic factor (GDNF) is repressed in the adult organism. However, rapid induction of this neuronal growth factor is observed following diverse neuronal insults and it is now widely accepted that the control of its expression could constitute a powerful target in neuropharmacology. We investigated the effects of the neuroprotective drug, riluzole, on the GDNF gene expression in glial cells. Exposure of C6 glioma cells to riluzole (1 µm) significantly increased GDNF protein and mRNA levels. Using luciferase reporter gene constructs encoding fragments of the 5′ untranslated region of the rat GDNF gene, we demonstrated that riluzole mediates its effect at the transcription level. Furthermore, luciferase assays revealed the presence of a negative regulatory region within the +343/+587 region of exon 1. This region was shown to contribute to the high sensitivity and specificity of the induction mediated by riluzole in the C6 glioma cell line at pharmacologically relevant concentrations. The effects of riluzole were inhibited by the mitogen‐activated protein kinase extracellular signal‐related kinase (MEK) inhibitor PD 98059. Together, these results indicated that the induction of GDNF release by riluzole in the C6 glioma cells results from the activation of its corresponding gene promoter through a signalling pathway involving MEK activity. This study suggests that the regulation of GDNF gene transcription in glial cells could contribute to the pharmacological properties of riluzole and possibly other neuroprotective drugs.
Gene expression is differentially regulated by neurotransmitters in embryonic neuronal cortical culture
Authors: Ghiani Cristina A. , Lelievre Vincent , Beltran‐Parrazal Luis , Sforza Daniel M. , Malvar Jemily , Smith Desmond J. , Charles Andrew C. , Ferchmin Pedro A. , de Vellis Jean 
Published: March 2006

AbstractNeurotransmitters and their receptors have been involved in both proper brain development and neurodevelopmental disorders. The role that nicotinic receptors play in immature cortical neurons was initially investigated by gene profiling using Affymetrix DNA arrays. Both short (15 min) and prolonged (18 h) treatments with nicotine did not induce modification in gene expression, whereas a significant down‐regulation of c‐fos protein levels was observed after 18 h treatment. Conversely, a brief treatment with the glutamatergic agonist NMDA triggered up‐regulation of immediate early genes and transcription factors, which remained unaffected by pre‐treatment for 18 h with nicotine. Calcium imaging studies revealed that NMDA activated a sustained increase in intracellular calcium concentration in the majority of neurons, whereas nicotine evoked only a transient calcium increase in a smaller percentage of neurons, suggesting that the calcium signalling response was correlated with activation of gene expression. Nicotine effects on immature cortical neurons perhaps do not require gene regulation but may be still acting on signalling pathways.
High susceptibility of neural stem cells to methylmercury toxicity: effects on cell survival and neuronal differentiation
Authors: Tamm Christoffer , Duckworth Joshua , Hermanson Ola , Ceccatelli Sandra 
Published: March 2006

AbstractNeural stem cells (NSCs) play an essential role in both the developing embryonic nervous system through to adulthood where the capacity for self‐renewal may be important for normal function of the CNS, such as in learning, memory and response to injury. There has been much excitement about the possibility of transplantation of NSCs to replace damaged or lost neurones, or by recruitment of endogenous precursors. However, before the full potential of NSCs can be realized, it is essential to understand the physiological pathways that control their proliferation and differentiation, as well as the influence of extrinsic factors on these processes. In the present study we used the NSC line C17.2 and primary embryonic cortical NSCs (cNSCs) to investigate the effects of the environmental contaminant methylmercury (MeHg) on survival and differentiation of NSCs. The results show that NSCs, in particular cNSCs, are highly sensitive to MeHg. MeHg induced apoptosis in both models via Bax activation, cytochrome c translocation, and caspase and calpain activation. Remarkably, exposure to MeHg at concentrations comparable to the current developmental exposure (via cord blood) of the general population in many countries inhibited spontaneous neuronal differentiation of NSCs. Our studies also identified the intracellular pathway leading to MeHg‐induced apoptosis, and indicate that NSCs are more sensitive than differentiated neurones or glia to MeHg‐induced cytotoxicity. The observed effects of MeHg on NSC differentiation offer new perspectives for evaluating the biological significance of MeHg exposure at low levels.