bluuebunny/crossref_metadata_2025_split huggingface dataset:
GABAergic neurosteroids mediate the effects of ethanol on long‐term potentiation in rat hippocampal slices
Authors: Izumi Yukitoshi , Murayama Kenki , Tokuda Kazuhiro , Krishnan Kathiresan , Covey Douglas F. , Zorumski Charles F. 
Published: September 2007

AbstractWe previously found that ethanol has complex effects on hippocampal synaptic plasticity, inhibiting long‐term potentiation (LTP) and long‐term depression by different mechanisms. The block of long‐term depression appears to be mediated by effects on N‐methyl‐d‐aspartate receptors, whereas the block of LTP involves augmented inhibition via γ‐aminobutyric acid‐A receptors (GABAARs). To pursue factors contributing to effects on LTP, we examined the ability of various concentrations of ethanol to block LTP in the CA1 region of rat hippocampal slices. Complete LTP block required 60 mm ethanol. LTP block was enhanced at lower ethanol concentrations in the presence of (3α5α)‐3‐hydroxypregnan‐20‐one, a GABAAR‐potentiating neurosteroid, suggesting that neurosteroids may be important contributors to the effects of ethanol on LTP. Consistent with this, we found that block of LTP by 60 mm ethanol was overcome by coadministration of a cyclodextrin that binds and removes lipophilic neurosteroids. More specifically, treatment of slices with finasteride, an agent that inhibits the synthesis of 5α‐reduced neurosteroids, or with an agent that inhibits the effects of 5α‐reduced neurosteroids on GABAARs overcame the effects of 60 mm ethanol on LTP. Taken together, these results indicate that acute production of GABAAR‐enhancing neurosteroids plays a key role in mediating the effects of ethanol on LTP.
Non‐motor behavioural impairments in parkin‐deficient mice
Authors: Zhu Xin‐Ran , Maskri Lyutha , Herold Christina , Bader Verian , Stichel Christine C. , Güntürkün Onur , Lübbert Hermann 
Published: September 2007

AbstractMutations in the parkin gene are the major cause of early‐onset familial Parkinson's disease (PD). We previously reported the generation and analysis of a knockout mouse carrying a deletion of exon 3 in the parkin gene. F1 hybridpa+/– mice were backcrossed to wild‐type C57Bl/6 for three more generations to establish apa–/–(F4) mouse line. The appearance of tyrosine hydroxylase‐positive neurons was normal in young and agedpa–/– (F4) animals. Loss of parkin function in mice did not enhance vulnerability of dopaminergic neurons to 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP) toxicity. However, thepa–/– (F4) mice displayed impaired exploration and habituation to a new environment and exhibited thigmotaxis behaviour in the open field and Morris water maze. Abnormal anxiety‐related behaviour ofpa–/– (F4) mice was also observed in the light/dark exploration test paradigm. Dopamine metabolism was enhanced in the striatum ofpa–/– (F4) mice, as revealed by increased homovanillic acid (HVA) content and a reduced ratio of dihydroxyphenylacetic acid (DOPAC)/HVA. The alterations found in the dopaminergic system could be responsible for the behavioural impairments ofpa–/– (F4) mice. Consistent with a recent observation of cognitive dysfunction in parkin‐linked patients with PD, our findings provide evidence of a physiological role of parkin in non‐motor behaviour, possibly representing a disease stage that precedes dopaminergic neuron loss.
BDNF/ TrkB interaction regulates migration of SVZ precursor cells via PI3‐K and MAP‐K signalling pathways
Authors: Chiaramello S. , Dalmasso G. , Bezin L. , Marcel D. , Jourdan F. , Peretto P. , Fasolo A. , De Marchis S. 
Published: September 2007

AbstractNeuroblasts born in the subventricular zone (SVZ) migrate along the rostral migratory stream, reaching the olfactory bulb (OB) where they differentiate into local interneurons. Several extracellular factors have been suggested to control specific steps of this process. The brain‐derived neurotrophic factor (BDNF) has been demonstrated to promote morphological differentiation and survival of OB interneurons. Here we show that BDNF and its receptor TrkB are expressed in vivo throughout the migratory pathway, implying that BDNF might also mediate migratory signals. By using in vitro models we demonstrate that BDNF promotes migration of SVZ neuroblasts, acting both as inducer and attractant through TrkB activation. We show that BDNF induces cAMP response element‐binding protein (CREB) activation in migrating neuroblasts via phosphatidylinositol 3‐kinase (PI3‐K) and mitogen‐activated protein kinase (MAP‐K) signalling. Pharmacological blockade of these pathways on SVZ explants significantly reduces CREB activation and impairs neuronal migration. This study identifies a function of BDNF in the SVZ system, which involves multiple protein kinase pathways leading to neuroblast migration.
Enhanced production and dendritic growth of new dentate granule cells in the middle‐aged hippocampus following intracerebroventricular FGF‐2 infusions
Authors: Rai Kiranmai S. , Hattiangady Bharathi , Shetty Ashok K. 
Published: September 2007

AbstractDeclined production and diminished dendritic growth of new dentate granule cells in the middle‐aged and aged hippocampus are correlated with diminished concentration of fibroblast growth factor‐2 (FGF‐2). This study examined whether increased FGF‐2 concentration in the milieu boosts both production and dendritic growth of new dentate granule cells in the middle‐aged hippocampus. The FGF‐2 or vehicle was infused into the posterior lateral ventricle of middle‐aged Fischer (F)344 rats for 2 weeks using osmotic minipumps. New cells born during the first 12 days of infusions were labeled via daily intraperitoneal injections of 5′‐bromodeoxyuridine (BrdU) and analysed at 10 days after the last BrdU injection. Measurement of BrdU+ cells revealed a considerably enhanced number of new cells in the subgranular zone (SGZ) and granule cell layer (GCL) of the dentate gyrus (DG) ipsilateral to FGF‐2 infusions. Characterization of β‐III tubulin+ neurons among newly born cells suggested an increased addition of new neurons to the SGZ/GCL ipsilateral to FGF‐2 infusions. Quantification of DG neurogenesis at 8 days post‐infusions via doublecortin (DCX) immunostaining also revealed the presence of an enhanced DG neurogenesis ipsilateral to FGF‐2 infusions. Furthermore, DCX+ neurons in FGF‐2‐infused rats exhibited enhanced dendritic growth compared with their counterparts in vehicle‐infused rats. Thus, subchronic infusion of FGF‐2 is efficacious for stimulating an enhanced DG neurogenesis from neural stem/progenitor cells in the middle‐aged hippocampus. As dentate neurogenesis is important for hippocampal‐dependent learning and memory and DG long‐term potentiation, strategies that maintain increased FGF‐2 concentration during ageing may be beneficial for thwarting some of the age‐related cognitive impairments.
Time, transients and elasticity
Authors: Haridas C. V. , Tuljapurkar Shripad 
Published: September 2007

AbstractHow does life history affects the short‐term elasticities of population growth rate? We decompose short‐term elasticity as a sum of (i) the effect of the perturbation in rates on the unperturbed population structure and (ii) the effect of the original vital rates on the difference in structure between the original and the perturbed population. We provide exact analytical formulas for these components. In a population at its stable stage distribution (SSD), short‐term elasticity is determined mainly by the SSD and reproductive value. In a non‐stable population, short‐term elasticity depends also on the projection of initial structure on the SSD, equal to population momentum. Non‐stable stage structures matter most to elasticity if stages are missing that take time to fill in. We show how the demographic damping rate of the original population determines the rate at which short‐term elasticity converges to its limiting values.
Oscillating trophic control induces community reorganization in a marine ecosystem
Authors: Litzow Michael A. , Ciannelli Lorenzo 
Published: September 2007

AbstractUnderstanding how climate regulates trophic control may help to elucidate the causes of transitions between alternate ecosystem states following climate regime shifts. We used a 34‐year time series of the abundance of Pacific cod (Gadus macrocephalus) and five prey species to show that the nature of trophic control in a North Pacific ecosystem depends on climate state. Rapid warming in the 1970s caused an oscillation between bottom–up and top–down control. This shift to top–down control apparently contributed to the transition from an initial, prey‐rich ecosystem state to the final, prey‐poor state. However, top–down control could not be detected in the final state without reference to the initial state and transition period. Complete understanding of trophic control in ecosystems capable of transitions between alternate states may therefore require observations spanning more than one state.
Hydrogenase‐ and outer membrane c‐type cytochrome‐facilitated reduction of technetium(VII) by Shewanella oneidensis MR‐1
Authors: Marshall Matthew J. , Plymale Andrew E. , Kennedy David W. , Shi Liang , Wang Zheming , Reed Samantha B. , Dohnalkova Alice C. , Simonson Cody J. , Liu Chongxuan , Saffarini Daad A. , Romine Margaret F. , Zachara John M. , Beliaev Alexander S. , Fredrickson James K. 
Published: September 2007

SummaryPertechnetate, 99Tc(VII)O4–, is a highly mobile radionuclide contaminant at US Department of Energy sites that can be enzymatically reduced by a range of anaerobic and facultatively anaerobic microorganisms, including Shewanella oneidensis MR‐1, to poorly soluble Tc(IV)O2(s). In other microorganisms, Tc(VII)O4– reduction is generally considered to be catalysed by hydrogenase. Here, we provide evidence that although the NiFe hydrogenase of MR‐1 was involved in the H2‐driven reduction of Tc(VII)O4–[presumably through a direct coupling of H2 oxidation and Tc(VII) reduction], the deletion of both hydrogenase genes did not completely eliminate the ability of MR‐1 to reduce Tc(VII). With lactate as the electron donor, mutants lacking the outer membrane c‐type cytochromes MtrC and OmcA or the proteins required for the maturation of c‐type cytochromes were defective in reducing Tc(VII) to nanoparticulate TcO2·nH2O(s) relative to MR‐1 or a NiFe hydrogenase mutant. In addition, reduced MtrC and OmcA were oxidized by Tc(VII)O4–, confirming the capacity for direct electron transfer from these OMCs to TcO4–. c‐Type cytochrome‐catalysed Tc(VII) reduction could be a potentially important mechanism in environments where organic electron donor concentrations are sufficient to allow this reaction to dominate.
Morpho‐anatomy of the lobopod Magadictyon cf. haikouensis from the Early Cambrian Chengjiang Lagerstätte, South China
Authors: Liu Jianni , Shu Degan , Han Jian , Zhang Zhifei , Zhang Xingliang 
Published: September 2007

Abstract Magadictyon haikouensis (Luo and Hu, 1999) from the Early Cambrian Chengjiang Lagerstätte, an incomplete specimen of a large lobopod with strong appendages, has been regarded as related to the lobopods Microdictyon and Onychodictyon. Newly discovered complete specimens of Magadictyon cf. haikouensis (found by the Early Life Institute field team) show that the taxon, in addition to its strong appendages with appendicules, also had a head bearing similar caecum‐like structures to those of the arthropod Naraoia and Chelicerate, ‘Peytoia’‐like mouthparts and frontal appendages. Because of their similarity, the caecum‐like structures of Magadictyon cf. haikouensis are considered to be homologous with those of stem‐group arthropods. The ‘Peytoia’‐like mouthparts and the frontal appendages are similar to those of the AOPK (Anomalocaris–Opabinia–Pambdelurion–Kerygmachela) group. In addition, the appendages with appendicules show that Magadictyon cf. haikouensis is closely related to Onychodictyon. Therefore, Magadictyon cf. haikouensis is regarded here as a rare transitional form between lobopods and arthropods. Besides, together with other lobopods, the morphology of Magadictyon cf. haikouensis demonstrates that the Cambrian lobopods appear to have been diverse and not particularly closely related to one another, and do not seem to represent a monophyletic clade.
Comparative histology of the vaginal–cloacal region in Squamata and its phylogenetic implications
Authors: Sánchez‐Martínez Paola María , Ramírez‐Pinilla Martha Patricia , Miranda‐Esquivel Daniel Rafael 
Published: September 2007

AbstractWe described the histology and morphology of the vaginal–cloacal region in 18 species from 12 Squamata families. This comparative study revealed a wide variation in the cloacal morphology. Fifteen morphological characters were considered to be primary homology hypotheses and were optimized over the topology derived from the parsimony analysis of the available soft morphological evidence, including the characters described in this study. The synapomorphies optimized for Squamata are bifid urodaeum, common urodaeal cavity with similar histological features of the urodaeal horns, and presence of glands in the anterior urodaeum; for Scleroglossa the synapomorphy is the lateral position of the vaginal intrusion into the anterior urodaeal chamber, for Nyctisaura + Scincomorpha the synapomorphy is the presence of a bifid posterior urodaeum; and for Xantusidae + Annulata it is the presence of simple glands in the anterior urodaeum. The central position of the vaginal intrusion into the urodaeal chamber and the intraepithelial position of the glandular unit in the anterior urodaeum behave as autapomorphies for Iguanidae. This study contributes evidence that defines the relationships within Scleroglossa. Cloacal features provide interesting information that is useful as a source of morphological characters for phylogenetic studies in Squamata.
The first cytogenetic report of fireflies (Coleoptera, Lampyridae) from Brazilian fauna
Authors: Dias Carolina M. , Schneider Marielle C. , Rosa Simone P. , Costa Cleide , Cella Doralice M. 
Published: September 2007

AbstractThe first cytogenetic analysis of fireflies from Brazilian fauna was carried out in this work. The investigation of two species of the subfamily Lampyrinae, Aspisoma maculatum and Photinus sp. (aff. pyralis), showed the diploid number 2n = 19 and an X0 sex determination system in males. These observations are similar to those already described for all the Lampyrinae species previously studied. In contrast, Bicellonycha lividipennis (Photurinae) revealed the karyotype 2n = 16 + neoXY, which has not yet been registered for any firefly species. The neoXY sex determination system encountered in this species probably arose through fusion between an ancestral X sex chromosome, belonging to the X0 system, and an autosomal element. This event also reduced the diploid number from 2n = 19, which is more frequent in the family Lampyridae, to 2n = 18 in B. lividipennis. The analysis of meiotic cells showed that the neoXY sexual bivalent of B. lividipennis exhibited a prominent terminal chiasma, indicating that the sex chromosomes are not wholly differentiated and still retain a region of homology. A review of the cytogenetic data known for the family Lampyridae was also documented in this work, as well as a discussion on the main trends of chromosomal evolution that seem to have occurred in this group.
Common Cultural Relationships in Corporate Governance across Developed and Emerging Financial Markets
Authors: Chan Alex W.H. , Cheung Hoi Yan 
Published: September 2007

This study investigates the corporate governance (CG) practice of business organisations in 43 countries with developed and emerging financial markets from the perspective of cross‐cultural psychology. We find significant relationships between CG practice and Hofstede's cultural dimensions, and discover that the cultural dimensions of power distance and uncertainty avoidance significantly explain the development of CG practice. These two cultural dimensions fully capture the power of stock market history to explain the development of CG practice across developed and emerging financial markets, which indicates that cultural factors are more important than the length of stock market history in the development of CG.Cette étude se propose d’étudier, dans une perspective de psychologie inter‐culturelle, la pratique de la gouvernance d’entreprise dans des organismes d’affaire de 43 pays différents dont les marchés financiers sont développés ou émergents. Nous trouvons une relation significative entre la pratique de la gouvernance d’entreprise et les dimensions culturelles de Hofstede. Nous montrons que les dimensions culturelles de distance du pouvoir et d’évitement de l’incertitude expliquent le développement de la pratique de la gouvernance d’entreprise. Ces deux dimensions culturelles déterminent totalement la puissance de l’histoire du marché boursier pour expliquer le développement de la pratique de la gouvernance d’entreprise sur des marchés financiers développés ou émergents. Les facteurs culturels ont donc plus de poids que la durée de l’histoire du marché boursier dans le développement de la pratique de la gouvernance d’entreprise.
When Thinking Rationally Increases Biases: The Role of Rational Thinking Style in Escalation of Commitment
Authors: Wong Kin Fai Ellick , Kwong Jessica Yuk Yee , Ng Carmen K. 
Published: September 2007

This paper reports three studies examining the relationship between the rational thinking style (RTS, i.e. individual differences in relying on a conscious, analytical, and relatively affect‐free information processing system) and decision quality in an escalation situation. In contrast to conventional wisdom that rational thinking increases decision quality, but consistent with the predictions derived from the cognitive dissonance theory, results of Studies 1 and 2 revealed that high scorers in Pacini and Epstein's (1999) rationality inventory were more likely to have escalation bias than were low scorers. The results further showed that only the ability component of rationality, not the engagement component, was positively correlated with escalating commitment. Similar patterns of results were obtained for situations when participants were personally responsible for prior decisions (Study 1) and when they were not (Study 2). Results of Study 3 showed that the underlying process responsible for the effect of RTS on the escalating tendency is that RTS increases beliefs in prior decisions, which in turn increases escalation. Implications for our understanding of escalation of commitment, rationality theory, and managerial practices are discussed.Cet article rend compte de 3 études examinant la relation entre le style de pensée rationnelle (RTS i.e. les différences individuelles reposent sur un système de traitement de l’information consciente, analytique et relativement libre d’affects) et la qualité de la décision dans une situation d’escalade d’engagement. Contrairement à l’opinion communément admise pour laquelle la pensée rationnelle accroît la qualité de la décision, mais consistante avec les prédictions découlant de la théorie de la dissonance cognitive, les résultats des études 1 et 2 indiquent que des personnes obtenant un score élevéà l’Inventaire Rationnel‐Expérientiel de Pacini et Esptein (1999) sont plus enclines à tomber dans le piège de l’escalade d’engagement que celles dont le score est bas. D’autres résultats montrent que la capacitéà la rationalité, non celle à l’engagement, est positivement corrélée avec l’escalade d’engagement. Des résultats semblables sont obtenus lors de situations où les participants sont personnellement responsables de leurs décisions antérieures (Etude 1) ou non (Etude 2). Les résultats de l’étude 3 montrent que le processus responsable de l’effet du RTS sur la tendance à s’engager est le suivant: il accroît les croyances dans les décisions antérieures qui augmentent à leur tour l’engagement. Ces résultats nous permettent de mieux comprendre l’escalade d’engagement, la théorie rationnelle et les pratiques managériales.
Bioluminescence imaging to monitor bladder cancer cell adhesion in vivo: a new approach to optimize a syngeneic, orthotopic, murine bladder cancer model
Authors: Jurczok Andreas , Fornara Paolo , Söling Ariane 
Published: September 2007

OBJECTIVETo improve the orthotopic murine bladder cancer model by using bioluminescent (BL) MB49 tumour cells for noninvasive in vivo monitoring of tumour growth and to examine the efficacy of integrin receptor‐blocking oligopeptides on preventing tumour cell adhesion in this improved bladder cancer model.MATERIALS AND METHODSThe capacity of oligopeptide combinations to interfere with tumour cell adhesion was assessed in vivo in a syngeneic, orthotopic, murine bladder cancer model. Tumour outgrowth was monitored noninvasively by bioluminescence imaging (BLI) after administration of luciferase‐expressing MB49LUC bladder cancer cells. The presence of tumour cells was verified histologically and immunohistochemically on paraffin wax‐embedded sections of excised bladders.RESULTSAnti‐adhesive oligopeptides effectively inhibited tumour outgrowth. BLI detected tumour cells at an early stage when there were no clinical signs of cancer in any of the mice. The technique has high sensitivity in detecting tumour cell implantation, but is less reliable in assessing tumour volume in advanced‐stage disease due to light attenuation in large tumours.CONCLUSIONSPeptides targeting adhesion molecules prevent attachment of bladder cancer cells to the injured bladder wall. BLI is a sensitive method for detecting luminescent bladder cancer cells in an orthotopic mouse model.
Robotic vs open radical cystectomy: prospective comparison of perioperative outcomes and pathological measures of early oncological efficacy
Authors: Wang Gerald J. , Barocas Daniel A. , Raman Jay D. , Scherr Douglas S. 
Published: September 2007

OBJECTIVETo prospectively compare perioperative and pathological outcomes in a consecutive series of patients undergoing radical cystectomy (RC) and urinary diversion by the open or the robotic approach.PATIENTS AND METHODSFrom February 2006 to April 2007, 54 consecutive patients underwent RC by one surgeon at our institution. Twenty‐one were open, while 33 utilized the da Vinci robotic system (Intuitive Surgical, Sunnyvale, CA, USA). Data was collected prospectively, including patient demographics, operative and postoperative variables, and pathological outcomes.RESULTSThe robotic cohort had decreased blood loss (400 vs 750 mL, P = 0.002) and transfusion requirement (2.0 vs 0.5 units, P = 0.007), but increased operative duration (390 vs 300 min, P = 0.03). The time to resumption of a regular diet (4 vs 5 days, P = 0.002) and the hospital stay (5 vs 8 days, P = 0.007) were decreased in the robotic group. Overall the complication rates were similar (24% open, 21% robotic, P = 0.3). The open cohort had more patients with extravesical disease (57 vs 28%, P = 0.03) and nodal metastasis (34 vs 19%, P = 0.04). There were three patients in the open group and two in the robotic with positive margins (P = 0.2). The median number of lymph nodes removed was similar in the open and robotic cohorts (20 vs 17, P = 0.6).CONCLUSIONRobotic‐assisted RC appears to offer some operative and perioperative benefits compared with the open approach without compromising pathological measures of early oncological efficacy, such as lymph node yield and margin status. Larger, randomized studies with long‐term follow‐up are required to confirm these findings and establish oncological equivalence.