bluuebunny/crossref_metadata_2025_split huggingface dataset:
The role of RNA editing of the serotonin 2C receptor in a rat model of oro‐facial neuropathic pain
Authors: Nakae Aya , Nakai Kunihiro , Tanaka Tatsuya , Hagihira Saotoshi , Shibata Masahiko , Ueda Koichi , Masimo Takashi 
Published: April 2008

AbstractWe examined whether infraorbital nerve injury affected the RNA editing efficiency of the serotonin (5HT) 2C receptor in the cervical spinal cord, in association with increased pain thresholds, and whether a 5HT reuptake inhibitor (fluvoxamine; Depromel®, Meiji Seika, Tokyo, Japan) altered this editing. Accordingly, we injured rats with an infraorbital nerve loose ligation and examined the pain thresholds, mRNA and mRNA editing of the 5HT2C receptor. We evaluated changes in mRNA editing and 5HT2C mRNA expression using cloning along with sequence analysis and quantitative reverse transcription‐polymerase chain reaction to compare samples taken at post‐injury day 28 from spinal cord sites, including the trigeminal nucleus caudalis, in naive, sham and injured rats (groups of each type had also received fluvoxamine). 5HT2C receptor expression was maintained post‐injury. The RNA editing efficiency was statistically significantly lower at molecular sites A and B in ipsilateral spinal cord samples from injured rats than in bilateral samples from naive and sham rats, and in contralateral samples from injured rats. After injury, the proportional presence of two receptor isoforms changed, i.e. statistically significantly less VNV and significantly more INV and ISV. The proportions reverted after fluvoxamine administration. The post‐injury change might be evidence of a functional adaptation mechanism that increases the expression of 5HT2C mRNA isoforms that encode receptors that are more sensitive to 5HT. This would activate the brainstem–spinal descending 5HT systems and, in effect, suppress nociceptive signals from primary afferent neurons to the spinal trigeminal nucleus caudalis.
Cortex‐ and striatum‐ derived neural stem cells produce distinct progeny in the olfactory bulb and striatum
Authors: Willaime‐Morawek Sandrine , Van Der Kooy Derek 
Published: April 2008

AbstractNeural stem cells can be isolated from the mouse embryonic cortex but do not persist in the adult cortex. In contrast, neural stem cells from the striatal embryonic germinal zone persist in the adult subependyma. Emx1‐lineage analysis revealed that cortex‐derived neural stem cells survive and migrate ventrally into the subependyma where they intermix with the host striatal neural stem cells [S. Willaime‐Morawek et al. (2006)J. Cell Biol. 175, 159–168]. Cortex‐derived cells proliferate faster in the subependyma and reach the olfactory bulb earlier than striatum‐derived cells. In the olfactory bulb, cortex‐derived cells produce more cells and more dopaminergic neurons in the glomerular layer than striatum‐derived cells. Cortex‐derived cells also give rise to more astrocytes and less neurons in the striatum than striatum‐derived cells. Thus, history matters; cortex‐derived neural stem cells in the subependyma give rise to progeny in the olfactory bulb and striatum but in different proportions than striatum‐derived neural stem cells.
Down‐regulation of insulin‐degrading enzyme by presenilin 1 V97L mutant potentially underlies increased levels of amyloid beta 42
Authors: Qin Wei , Jia Jianping 
Published: April 2008

AbstractAmyloid beta (Aβ)42 plays a pivotal role in Alzheimer's disease. We previously reported a novel presenilin (PS)1 mutant (V97L) that was expressed in related patients with early onset Alzheimer's disease. We found that patients with the V97L mutation had increased levels of extracellular and intracellular Aβ42. Here we found that the increased extracellular level of Aβ42 was always accompanied by a reduction of insulin‐degrading enzyme (IDE) activity on the plasma membranes. However, increase of intracellular Aβ42 was associated with decreased expression and activity of IDE in the cytosol and endoplasmic reticulum in the PS1 V97L mutant‐transfected human SH‐SY5Y cell line. These studies indicate that pathological levels of Aβ42 may be caused by the negative effects of PS1 (V97L) on IDE expression and activity. Our findings provide evidence for the molecular basis of familial Alzheimer's disease pathogenesis.
Chronic cold exposure increases RGS7 expression and decreases α2‐autoreceptor‐mediated inhibition of noradrenergic locus coeruleus neurons
Authors: Jedema Hank P. , Gold Stephen J. , Gonzalez‐Burgos Guillermo , Sved Alan F. , Tobe Ben J. , Wensel Theodore G. , Grace Anthony A. 
Published: April 2008

AbstractChronic stress exposure alters the central noradrenergic neurons originating from the locus coeruleus (LC). Previously, we demonstrated that evoked increases in the firing rate of LC neurons and their release of norepinephrine are enhanced following chronic cold exposure. In the present studies, we tested the hypothesis that reduced feedback inhibition of LC neurons might underlie these alterations in LC activity by examining the effect of α2‐autoreceptor stimulation on LC activity in chronically stressed rats usingin vivoandin vitrosingle unit recordings. Given that regulators of G‐protein signaling (RGS) proteins can impact the coupling of α2‐autoreceptors to downstream signaling cascades, we also explored the expression of several RGS proteins following chronic stress exposure. We observed that the α2‐autoreceptor‐evoked inhibition of LC neurons was reduced and that the expression of RGS7 was increased following chronic stress exposure. Finally, we demonstrated that intracellular administration of RGS7 via patch clamp electrodes mimicked the stress‐induced decrease in clonidine‐evoked autoreceptor‐mediated inhibition. These novel data provide a mechanism to explain how chronic stress‐induced alterations in receptor coupling can result in changes in α2‐autoreceptor control of noradrenergic function throughout the central nervous system, potentially leading to alterations in anxiety‐related behaviors, and may suggest novel therapeutic targets for the treatment of mood and anxiety disorders.
Expression and function of striatal enriched protein tyrosine phosphatase is profoundly altered in cerebral ischemia
Authors: Braithwaite Steven P. , Xu Jian , Leung John , Urfer Roman , Nikolich Karoly , Oksenberg Donna , Lombroso Paul J. , Shamloo Mehrdad 
Published: April 2008

AbstractStriatal enriched protein tyrosine phosphatase (STEP) acts in the central nervous system to dephosphorylate a number of important proteins involved in synaptic function including ERK and NMDA receptor subunits. These proteins are also linked to stroke, in which cerebral ischemia triggers a complex cascade of events. Here we demonstrate that STEP is regulated at both the transcriptional and the post‐transcriptional levels in rat models of cerebral ischemia and that its regulation may play a role in the outcome of ischemic insults. After transient middle cerebral artery occlusion, there are profound decreases in the levels of STEP mRNA, whilst in global ischemia STEP mRNA is selectively down‐regulated in areas susceptible to ischemic damage. In a neuroprotective preconditioning paradigm, and in regions of the brain that are relatively resistant to ischemic damage, STEP mRNA levels are increased. Furthermore, there is a significant processing of STEP after ischemia to generate a novel species, STEP33, resulting in a redistribution of STEP from membrane‐bound to soluble compartments. Concomitant with the cleavage of mature forms of STEP, there are changes in the phosphorylation state of ERK. We show that the cleavage of STEP leads to a catalytically active form, but this cleaved form no longer binds to and dephosphorylates its substrate pERK. Therefore, in response to ischemic insults, there are profound reductions in both the amount and the activity of STEP, its localization, as well as the activity of one of its key substrates, pERK. These changes in STEP may reflect a critical role in the outcomes of ischemic brain injury.
A primitive social circuit: vasotocin–substance P interactions modulate social behavior through a peripheral feedback mechanism in goldfish
Authors: Thompson R. R. , Walton J. C. , Bhalla R. , George K. C. , Beth E. H. 
Published: April 2008

AbstractAt its core, the polyvagal theory proposes that peptides affect simple social behaviors through influences on hindbrain autonomic processes. To test this mechanism, we compared the effects of fore‐ and hindbrain infusions of vasotocin (VT) on social approach behavior in goldfish. VT infusions into the 4th ventricle, which ink infusions verified did not move rostrally to the forebrain, inhibited social approach at a lower dose than did infusions into the 3rd ventricle, which did diffuse to the hindbrain. Thus, VT actions in the hindbrain appear to modulate this simple social behavior. We then identified a population of substance P (SP)‐immunoreactive cells in the hindbrain that are encapsulated by putative VT terminals, and determined that those cells project to the periphery. Injecting SP peripherally, as with infusing VT centrally, inhibited social approach, and peripheral injections of an SP antagonist, but not central infusions, abolished the behavioral effects of central VT infusions. We therefore propose that VT inhibits social approach by activating SP cells in the hindbrain, which then induce changes in body state that feed back to the brain. Central VT infusions did not inhibit feeding, suggesting that this VT mechanism selectively affects appetitive social responses. Because VT projections to the hindbrain are highly conserved in vertebrates, influences on peripheral feedback processes like the one we have described in goldfish may reflect how VT affected simple social behaviors in ancestral vertebrates and thus preadapted members of this peptide family to play increasingly complex roles in social and emotional regulation in modern animals.
Neonatal stimulation of 5‐HT2receptors reduces androgen receptor expression in the rat anteroventral periventricular nucleus and sexually dimorphic preoptic area
Authors: Dakin C. L. , Wilson C. A. , Kalló I. , Coen C. W. , Davies D. C. 
Published: April 2008

AbstractMasculinization of the brain is dependent upon a perinatal surge in testosterone. It also requires a transient decrease in hypothalamic 5‐HT concentration and turnover and an increase in androgen receptor (AR) expression during the second postnatal week. We have previously shown that increasing 5‐HT activity over this period in male or androgenized female rats feminizes their adult behaviour and also feminizes the size of their anteroventral periventricular nucleus (AVPV) and sexually dimorphic nucleus of the preoptic area (SDN‐POA). To investigate the role of 5‐HT in sexual differentiation of the brain, 5‐HT activity was raised over postnatal days 8–16 in male, female and androgenized female rats by daily administration of the 5‐HT2receptor agonist (–)[2,5 dimethoxy‐4‐iodophenyl]‐2‐amino propane hydrochloride [(–)DOI]. By postnatal day 18, the size of the AVPV and SDN‐POA was sexually dimorphic; their sizes were feminized by (–)DOI treatment. In the absence of (–)DOI treatment, there were significantly more AR‐immunoreactive cells in the AVPV of males, and in the SDN‐POA of males and androgenized females, than in those of females on postnatal day 18. (–)DOI treatment reduced the number of AR‐immunoreactive cells in the AVPV and SDN‐POA of males and androgenized females, but not of females, by postnatal day 18. These results suggest that 5‐HT2receptor activation can influence sexual differentiation of the brain by controlling AR expression.
Characterization of the vulnerability to repeated stress in Fischer 344 rats: possible involvement of microRNA‐mediated down‐regulation of the glucocorticoid receptor
Authors: Uchida Shusaku , Nishida Akira , Hara Kumiko , Kamemoto Toshiki , Suetsugi Masatomo , Fujimoto Michiko , Watanuki Toshio , Wakabayashi Yusuke , Otsuki Koji , McEwen Bruce S. , Watanabe Yoshifumi 
Published: April 2008

AbstractIn the present study, we established and characterized an animal model of vulnerability to repeated stress. We found that control Sprague–Dawley (SD) rats showed a gradual decrease in the HPA axis response following 14 days of repeated restraint stress, whereas Fischer 344 (F344) rats did not show such HPA axis habituation. Similar habituation was observed in the expression of c‐fos mRNA, corticotropin‐releasing hormone hnRNA, and phospho‐CREB and phospho‐ERK proteins in the hypothalamic paraventricular nucleus (PVN) of SD rats, but not in the F344 rats. In addition, repeatedly restrained F344 rats exhibited decreased cell proliferation in the dentate gyrus of the hippocampus and increased anxiety‐related behaviours, while repeatedly restrained SD rats exhibited a selective enhancement of hippocampal cell proliferation in the ventral area. Moreover, we found a lower expression of glucocorticoid receptor (GR) protein, but not mRNA, in the PVN of F344 rats compared to SD rats. We also identified that microRNA (miR)‐18a inhibited translation of GR mRNA in cultured neuronal cells and that increased expression of miR‐18a in the PVN was observed in F344 rats compared with SD rats. These strain differences in GR protein levels were not found in the hippocampus and prefrontal cortex, and the expression of miR‐18a was much lower in these brain regions than in the PVN. Our results suggest that F344 rats could be a useful animal model for studying vulnerability to repeated stress, and that miR‐18a‐mediated down‐regulation of GR translation may be an important factor to be considered in susceptibility to stress‐related disorders.
Paraplegia after thoracotomy under combined general and epidural anesthesia in a child
Authors: ALLISON C.E. , ARONSON D.C. , GEUKERS V.G.M. , VAN DEN BERG R. , SCHLACK W.S. , HOLLMANN M.W. 
Published: April 2008

SummaryA 9‐year‐old boy underwent a thoracotomy for excision of his right third rib under combined general and epidural anesthesia for a Ewings sarcoma. Postoperatively, he was found to have a complete T2–3 paraplegia. Permanent paraplegia was described as a rare complication of thoracotomy in adults, and very rarely after epidural analgesia in adults and babies. This was the first report in a child.
Scaling of respiration to nitrogen in leaves, stems and roots of higher land plants
Authors: Reich Peter B. , Tjoelker Mark G. , Pregitzer Kurt S. , Wright Ian J. , Oleksyn Jacek , Machado Jose‐Luis 
Published: April 2008

AbstractUsing a database of 2510 measurements from 287 species, we assessed whether general relationships exist between mass‐based dark respiration rate and nitrogen concentration for stems and roots, and if they do, whether they are similar to those for leaves. The results demonstrate strong respiration–nitrogen scaling relationships for all observations and for data averaged by species; for roots, stems and leaves examined separately; and for life‐forms (woody, herbaceous plants) and phylogenetic groups (angiosperms, gymnosperms) considered separately. No consistent differences in the slopes of these log–log scaling relations were observed among organs or among plant groups, but respiration rates at any common nitrogen concentration were consistently lower on average in leaves than in stems or roots, indicating that organ‐specific relationships should be used in models that simulate respiration based on tissue nitrogen concentrations. The results demonstrate both common and divergent aspects of tissue‐level respiration–nitrogen scaling for leaves, stems and roots across higher land plants, which are important in their own right and for their utility in modelling carbon fluxes at local to global scales.
Coexistence through spatio‐temporal heterogeneity and species sorting in grassland plant communities
Authors: Questad Erin J. , Foster Bryan L. 
Published: April 2008

AbstractThe effect of spatial heterogeneity on species coexistence relies on the degree of niche heterogeneity in the habitat and the ability of species to exploit the available niche opportunities. We studied species coexistence in a perennial grassland, and tested whether small‐scale disturbances create environmental heterogeneity that affects coexistence and whether the functional diversity of species in the species pool affects the ability of community composition to reflect heterogeneity through species sorting. We manipulated the spatio‐temporal heterogeneity of disturbance and the functional diversity of species added as seed and measured their impact on the spatial turnover of species composition. Disturbance increased environmental heterogeneity and spatial turnover, and the effect of heterogeneity on turnover was greatest in the presence of a functionally diverse species pool, showing the importance of trait variation among species for exploiting environmental heterogeneity, and suggesting that coexistence occurred due to species sorting among heterogeneous niches.
A cross‐system synthesis of consumer and nutrient resource control on producer biomass
Authors: Gruner Daniel S. , Smith Jennifer E. , Seabloom Eric W. , Sandin Stuart A. , Ngai Jacqueline T. , Hillebrand Helmut , Harpole W. Stanley , Elser James J. , Cleland Elsa E. , Bracken Matthew E. S. , Borer Elizabeth T. , Bolker Benjamin M. 
Published: April 2008

AbstractNutrient availability and herbivory control the biomass of primary producer communities to varying degrees across ecosystems. Ecological theory, individual experiments in many different systems, and system‐specific quantitative reviews have suggested that (i) bottom–up control is pervasive but top–down control is more influential in aquatic habitats relative to terrestrial systems and (ii) bottom–up and top–down forces are interdependent, with statistical interactions that synergize or dampen relative influences on producer biomass. We used simple dynamic models to review ecological mechanisms that generate independent vs. interactive responses of community‐level biomass. We calibrated these mechanistic predictions with the metrics of factorial meta‐analysis and tested their prevalence across freshwater, marine and terrestrial ecosystems with a comprehensive meta‐analysis of 191 factorial manipulations of herbivores and nutrients. Our analysis showed that producer community biomass increased with fertilization across all systems, although increases were greatest in freshwater habitats. Herbivore removal generally increased producer biomass in both freshwater and marine systems, but effects were inconsistent on land. With the exception of marine temperate rocky reef systems that showed positive synergism of nutrient enrichment and herbivore removal, experimental studies showed limited support for statistical interactions between nutrient and herbivory treatments on producer biomass. Top–down control of herbivores, compensatory behaviour of multiple herbivore guilds, spatial and temporal heterogeneity of interactions, and herbivore‐mediated nutrient recycling may lower the probability of consistent interactive effects on producer biomass. Continuing studies should expand the temporal and spatial scales of experiments, particularly in understudied terrestrial systems; broaden factorial designs to manipulate independently multiple producer resources (e.g. nitrogen, phosphorus, light), multiple herbivore taxa or guilds (e.g. vertebrates and invertebrates) and multiple trophic levels; and – in addition to measuring producer biomass – assess the responses of species diversity, community composition and nutrient status.
Biodiversity of polycyclic aromatic hydrocarbon‐degrading bacteria from deep sea sediments of the Middle Atlantic Ridge
Authors: Cui Zhisong , Lai Qiliang , Dong Chunming , Shao Zongze 
Published: April 2008

SummaryThe bacteria involved in the biodegradation of polycyclic aromatic hydrocarbons (PAHs) in deep sea subsurface environments are largely unknown. In order to reveal their biodiversity, sediments from 2.2 m under the bottom surface at a water depth of 3542 m were sampled on the Middle Atlantic Ridge with a gravity column sampler. The sediments were promptly enriched with either crude oil or a mixture of PAHs (naphthalene, phenanthrene and pyrene) as the sole carbon source, and further enriched with the PAH mixture mentioned above in the lab. The resulting consortia were named C2CO and C2PPN respectively. Their bacterial composition was analysed with plate cultivation, PCR‐DGGE and 16S rDNA library analysis. On plates, isolates belonging to Pseudoalteromonas, Halomonas, Marinobacter, Thalassospira and Tistrella dominated the culturable populations. With PCR‐DGGE, five major bands closely related to Cycloclasticus, Alteromonas, Thalassospira, Alcanivorax and Rhodospirillaceae were detected in consortium C2CO, while only one major band of Cycloclasticus was detected in consortium C2PPN. In addition, the dynamics of community structure in response to aromatic substrate alterations were examined. As a result, three ribotypes of Cycloclasticus were detected by 16S rDNA library analysis, one which played a key role in phenanthrene degradation; two Alteromonas bacteria dominated the naphthalene reselected consortium. Although bacteria of the two genera grew as the main members of the communities, none of them were isolated, probably owing to their poor cultivability. These results confirm that bacteria of Cycloclasticus are important obligate PAH degraders in marine environments, and coexist with other degrading bacteria that inhabit the deep subsurface sediment of the Atlantic. This supports the view that PAH accumulation and bioattenuation occur in remote areas consistently and continuously.
Clinical and epidemiological features of patients with genitourinary tract tumour in a blackfoot disease endemic area of Taiwan
Authors: Tan Lia‐Beng , Chen Kow‐Tong , Guo How‐Ran 
Published: April 2008

OBJECTIVESTo evaluate the clinical and epidemiological characteristics of patients with genitourinary (GU) tract transitional cell carcinoma (TCC) in an endemic area of blackfoot disease (BFD), the arsenic‐exposed group, to compare them with characteristics among other non‐BFD endemic areas (unexposed group).PATIENTS AND METHODSIn all, 474 patients with pathologically diagnosed GU‐TCC were enrolled in the study. All follow‐up data were prospectively collected and entered into a database throughout the study period. Statistical analysis was used to determine the association between clinical variables and prognosis, and multivariate regression models were used to assess the association between arseniasis and mortality from GU‐TCC.RESULTSThere were no significant differences between the groups in age, sex, tumour stage and grade. However, the exposed group had a significantly higher proportion of females. The overall 5‐year survival rate of patients with upper urinary tract (UUT) TCC was 49%, and the two groups had similar 5‐year survival rates. The overall 5‐year survival rate of patients with urinary bladder (UB) TCC was 68.3%, and there was a statistically significant difference in survival between the groups, with a 5‐year survival rate of 58.7% for the exposed and 72.4% for the unexposed group. For patients with early‐stage (pTa and pT1) UB cancers, the death rate was five times higher in exposed patients with tumour progression and recurrence after transurethral resection of bladder tumour than in the unexposed group.CONCLUSIONSThere was a significantly higher mortality rate for UB‐TCC among exposed patients in the area endemic for arseniasis than in those from other non‐endemic areas. The arsenic content of artesian‐well water might contribute to the increased ratio of female patients with GU‐TCC and the unusually high incidence of UUT‐TCC in the BFD endemic area in Taiwan.