bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrical and neurotransmitter activity of mature neurons derived from mouse embryonic stem cells by Sox‐1 lineage selection and directed differentiation
Authors: Lang R. J. , Haynes J. M. , Kelly J. , Johnson J. , Greenhalgh J. , O'Brien C. , Mulholland E. M. , Baker L. , Munsie M. , Pouton C. W. 
Published: January 2005

AbstractSx1TV2/16C is a mouse embryonic stem (ES) cell line in which one copy of the Sox1 gene, an early neuroectodermal marker, has been targeted with a neomycin (G418) selection cassette. A combination of directed differentiation with retinoic acid and G418 selection results in an enriched neural stem cell population that can be further differentiated into neurons. After 6–7 days post‐plating (D6–7PP) most neurons readily fired tetrodotoxin (TTX)‐sensitive action potentials due to the expression of TTX‐sensitive Na+ and tetraethylammonium (TEA)‐sensitive K+ channels. Neurons reached their maximal cell capacitance after D6–7PP; however, ion channel expression continued until at least D21PP. The percentage of cells receiving spontaneous synaptic currents (s.s.c.) increased with days in culture until 100% of cells received a synaptic input by D20PP. Spontaneous synaptic currents were reduced in amplitude and frequency by TTX, or upon exposure to a Ca2+‐free, 2.5 mm Mg2+ saline. S.s.c. of rapid decay time constants were preferentially blocked by the nonNMDA glutamatergic receptor antagonists CNQX or NBQX. Ca2+ levels within ES cell‐derived neurons increased in response to glutamate receptor agonists l‐glutamate, AMPA, N‐methyl‐d‐aspartate (NMDA) and kainic acid and to acetylcholine, ATP and dopamine. ES cell‐derived neurons also generated cationic and Cl–‐selective currents in response to NMDA and glycine or GABA, respectively. It was concluded that ES‐derived neurons fire action potentials, receive excitatory and inhibitory synaptic input and respond to various neurotransmitters in a manner akin to primary central neurons.
Mutant huntingtin affects the rate of transcription of striatum‐specific isoforms of phosphodiesterase 10A
Authors: Hu Haibei , McCaw Elizabeth A. , Hebb Andrea L. O. , Gomez Geraldine T. , Denovan‐Wright Eileen M. 
Published: January 2005

AbstractHuntington's disease (HD) is caused by the inheritance of a copy of the gene encoding mutant huntingtin with an expanded CAG repeat. Phosphodiesterase 10A (PDE10A) mRNA decreases in transgenic HD mice expressing exon 1 of the human huntingtin gene (HD). The mouse PDE10A mRNA is expressed through alternative splicing and polyadenylation in a tissue‐specific manner and that transcription of striatal PDE10A mRNA is driven by two promoters. PDE10A2 is the predominant isoform of the gene is expressed in the striatum. Using in situ hybridization and quantitative RT‐PCR, we determined that decreased steady‐state levels of PDE10A2 mRNA were caused by an altered transcription initiation rate rather than by post‐transcriptional mRNA instability in HD mice. Transcription from three initiation sites located within a 50‐bp region in the PDE10A2‐specific promoter was differentially affected by the presence of the mutant huntingtin transgene. The mouse and human PDE10A2 promoters are highly conserved with respect to the relative position of cis‐regulatory elements. Several transcription factors that have been shown to interact with mutant huntingtin, including Sp1, neuron restrictive silencing factor, TATA‐binding protein and cAMP‐response element binding protein, are unlikely to be involved in mutant huntingtin‐induced PDE10A2 transcriptional dysregulation.
Distinct modulatory effects of sleep on the maintenance of hippocampal and medial prefrontal cortex LTP
Authors: Romcy‐Pereira Rodrigo , Pavlides Constantine 
Published: January 2005

AbstractBoth human and animal studies support the idea that memory consolidation of waking experiences occurs during sleep. In experimental models, rapid‐eye‐movement (REM) sleep has been shown to be necessary for cortical synaptic plasticity and for the acquisition of spatial and nonspatial memory. Because the hippocampus and medial prefrontal cortex (mPFC) play distinct and important roles in memory processing, we sought to determine the role of sleep in the maintenance of long‐term potentiation (LTP) in the dentate gyrus (DG) and mPFC of freely behaving rats. Animals were implanted with stimulating and recording electrodes, either in the medial perforant path and DG or CA1 and mPFC, for the recording of field potentials. Following baseline recordings, LTP was induced and the animals were assigned to three different groups: REM sleep‐deprived (REMD), total sleep‐deprived (TSD) and control which were allowed to sleep (SLEEP). The deprivation protocol lasted for 4 h and the recordings were made during the first hour and at 5, 24 and 48 h following LTP induction. Our results show that REMD impaired the maintenance of late‐phase (48‐h) LTP in the DG, whereas it enhanced it in the mPFC. Sleep, therefore, could have distinct effects on the consolidation of different forms of memory.
Blocking the R‐type (Cav2.3) Ca2+ channel enhanced morphine analgesia and reduced morphine tolerance
Authors: Yokoyama Kazuaki , Kurihara Takashi , Saegusa Hironao , Zong Shuqin , Makita Koshi , Tanabe Tsutomu 
Published: January 2005

AbstractMorphine is the drug of choice to treat intractable pain, although prolonged administration often causes undesirable side‐effects including analgesic tolerance. It is speculated that voltage‐dependent Ca2+ channels (VDCCs) play a key role in morphine analgesia and tolerance. To examine the subtype specificity of VDCCs in these processes, we analysed mice lacking N‐type (Cav2.2) or R‐type (Cav2.3) VDCCs. Systemic morphine administration or exposure to warm water swim‐stress, known to induce endogenous opioid release, resulted in greater analgesia in Cav2.3−/− mice than in controls. Moreover, Cav2.3−/− mice showed resistance to morphine tolerance. In contrast, Cav2.2−/− mice showed similar levels of analgesia and tolerance to control mice. Intracerebroventricular (i.c.v.) but not intrathecal (i.t.) administration of morphine reproduced the result of systemic morphine in Cav2.3−/− mice. Furthermore, i.c.v. administration of an R‐type channel blocker potentiated morphine analgesia in wild‐type mice. Thus, the inhibition of R‐type Ca2+ current could lead to high‐efficiency opioid therapy without tolerance.
Cortical and medial amygdala are both involved in the formation of olfactory offspring memory in sheep
Authors: Keller Matthieu , Perrin Gaëlle , Meurisse Maryse , Ferreira Guillaume , Lévy Frédéric 
Published: January 2005

AbstractEwes form a selective olfactory memory for their lambs after 2 h of mother–young interaction following parturition. Once this recognition is established, ewes will subsequently reject any strange lamb approaching the udder (i.e. maternal selectivity). The present study tested the functional contribution of different amygdala nuclei to lamb olfactory memory formation. Using the anaesthetic lidocaine, cortical, medial or basolateral nuclei of the amygdala were transiently inactivated during lamb odour memory formation. Reversible inactivation of either cortical or medial amygdala during the first 8 h postpartum impaired lamb olfactory recognition, whereas inactivation of the basolateral nucleus or infusion of artificial cerebrospinal fluid did not. Control experiments indicate that inactivation of the cortical and medial nuclei of the amygdala specifically disrupt memory formation rather than olfactory perception or memory retrieval. These findings show that both nuclei of the amygdala are required for the formation of a lamb olfactory memory and suggest functional interaction between these two nuclei.
Gene expression profiles associated with survival of individual rat dentate cells after endogenous corticosteroid deprivation
Authors: Nair S. M. , Karst H. , Dumas T. , Phillips R. , Sapolsky R. M. , Rumpff‐van Essen L. , Maslam S. , Lucassen P. J. , Joëls M. 
Published: January 2005

AbstractRemoval of circulating corticosterone by adrenalectomy (ADX) leads to apoptosis after 3 days in a small population of rat dentate granule neurons, whereas most surrounding cells remain viable. Interestingly, a specific expression profile is triggered in surviving granule cells that may enhance their survival. Hippocampal slices prepared 1, 2 or 3 days after ADX or sham operation were stained ex vivo with Hoechst 33258, which serves to identify apoptotic neurons. After electrophysiological analysis, multiple gene expression in surviving individual granule cells was assessed by linear antisense RNA amplification and hybridization to slot blots containing various neuronal cDNAs. Hierarchical clustering and principal component analysis was performed on two physiological variables and 14 mRNA ratios from ADX cells from every time point. Our results indicate that surviving 3‐day ADX granule cells display lower membrane capacitance, lower relative N‐methyl‐d‐aspartate (NMDA) R1 mRNA expression and higher relative mineralocorticoid receptor (MR), α1A voltage‐gated Ca‐channel, Bcl‐2 and NMDA R2C mRNA expression. Some 1‐ and 2‐day ADX cells cluster with these 3‐day survivors; therefore, one or more components of their mRNA expression profile may represent predictive markers for apoptosis resistance. The functional relevance of two candidate genes was tested by in vivo local over‐expression in the same model system; of these, Bcl‐2 conferred partial protection when induced shortly before ADX. Therefore, removal of corticosteroids triggers a specific gene expression profile in surviving dentate granule cells; key components of this profile may be associated with their survival.
Triclosan reduces microsomal prostaglandin E synthase‐1 expression in human gingival fibroblasts
Authors: Mustafa M. , Wondimu B. , Yucel‐Lindberg T. , Kats‐Hallström A. T. , Jonsson A. S. , Modéer T. 
Published: January 2005

AbstractObjective: The effect of triclosan (2,4,4′‐trichloro‐2′‐hydroxydiphenyl ether) on the expression of cyclooxygenase‐2 (COX‐2) and microsomal prostaglandin E synthase‐1 (mPGES‐1) and on the translocation of the nuclear factor‐κB (NF‐κB) in relation to prostaglandin E2 (PGE2) production was investigated in human gingival fibroblasts challenged with tumor necrosis factor α (TNFα).Methods: Fibroblasts were established from gingival biopsies obtained from six children. COX‐2 mRNA and protein expression was quantified using mRNA quantitation and enzyme immunometric assay kits. mPGES‐1 mRNA was analysed by RT‐PCR, mPGES‐1 protein and NF‐κB translocation by immunoblotting. PGE2 was determined by radioimmunoassay.Results: The cytokine TNFα enhanced the expression of mRNA as well as the protein levels of both COX‐2 and mPGES‐1 and subsequently the production of PGE2 in gingival fibroblasts. Treatment of gingival fibroblasts with triclosan (1 μg/ml) significantly reduced the stimulatory effect of TNFα (10 ng/ml) on the expression of mPGES‐1 at both the mRNA and the protein level by an average of 21% and 43%, respectively, and subsequently the production of PGE2 (p<0.01). Triclosan did not, however, affect the translocation of NF‐κB or the expression of COX‐2 in TNFα‐stimulated cells.Conclusion: The results show that triclosan reduces the augmented biosynthesis of PGE2 by inhibiting the mRNA and the protein expression of mPGES‐1 in gingival fibroblasts. This finding may partly explain the anti‐inflammatory effect of the agent previously reported in clinical studies.
Histologic, histomorphometric and immunohistologic changes of the gingival tissues immediately following mandibular osteodistraction
Authors: Kruse‐Lösler Birgit , Flören Christian , Stratmann Udo , Joos Ulrich , Meyer Ulrich 
Published: January 2005

AbstractObjectives: Even though osteogenesis after osteodistraction has been investigated in numerous experimental studies, there is limited information focusing on the influence of well‐defined mechanical distraction forces on the associated gingival tissues.Material and Methods: In a study including 48 rabbits, mandibular osteodistraction was performed in vertically osteotomized mandibular body, using defined distraction protocols with physiologic, moderate and hyperphysiologic forces. The soft tissues overlying the distraction gap were harvested finally for histologic, immunohistologic and histomorphometric investigations.Results: The control group without distraction showed the typical architecture and thickness of normal gingiva. In groups with distracted mandibles, an accelerating atrophy of gingiva depending on the degree of mechanical loading was obvious, characterized by decreasing thickness of epithelial layer, loss of rete ridges and disorganization of the different cell layers with a high number of apoptotic cells. In lamina propria collagen fibres were reduced and elastic fibres increased. Histomorphometric analysis revealed significant correlation between degree of distraction and atrophy in overlying soft tissues.Conclusion: This rabbit model of mandibular lengthening shows an accelerating atrophy in the covering soft tissues following hyperphysiologic distraction. The long‐term outcome of these distraction‐related soft‐tissue alterations remains unclear. The atrophic changes may likely be of temporary nature.
Tobacco smoking and subgingival dental calculus
Authors: Bergström Jan 
Published: January 2005

AbstractObjective: A radiographic investigation into the relationship between tobacco smoking and subgingival dental calculus was conducted in an adult population, including 48 current smokers, 57 former smokers, and 125 non‐smokers.Material and Methods: Assessment of subgingival calculus was based on a full set of radiographs. Mesial and distal root surfaces were assessed as to presence or absence of radiopaque deposits apical to the cemento‐enamel junction. The severity of subgingival calculus deposition, labeled subgingival calculus load, was estimated from both the total number and the proportion of proximal sites affected.Results: The overall prevalence of individuals exhibiting at least one subgingival calculus positive site was 43%, ranging from 15% in age stratum 20–34 years to 72% in age stratum 50–69 years. The prevalence among current smokers, former smokers, and non‐smokers was 71%, 53%, and 28%, respectively. The differences between smoking groups were statistically significant (p<0.001). The mean subgingival calculus load of current smokers, former smokers, and non‐smokers was 3.4, 1.2, and 0.6 affected sites per person, respectively, or expressed as mean proportions, 6.2%, 2.4%, and 1.1%, respectively. The association between smoking and subgingival calculus load was statistically significant (p<0.001). The subgingival calculus load increased with increasing smoking exposure, suggesting a dose–response relationship.Conclusion: The present observations in dentally aware adults indicate a strong and independent impact of tobacco smoking on subgingival calculus deposition.
Response rate and nonresponse bias in a questionnaire survey of dentists
Authors: Parashos Peter , Morgan Michael V. , Messer Harold H. 
Published: January 2005

Abstract –  Objectives:  (a) To report on response rate and nonresponse bias of a questionnaire survey of dentists. (b) To make recommendations for future questionnaire survey research in dentistry.Methods:  A questionnaire was mailed to a stratified systematic sample of 908 Australian dentists. The strategy included three mailings, a final telephonic contact, university stationery, paid reply envelopes and personalized correspondence. Nonresponse bias was assessed by comparing responses to a simple ‘yes/no’ question from each contact (late responders), and by comparing demographic information (nonresponders).Results:  The response rate achieved was 87% and there was no evidence of nonresponse bias based on practice location or year of graduation. The cumulative proportions of ‘yes/no’ responses essentially remained constant after each contact, but significantly more late responders answered in the negative to the test question than did early responders. The telephonic contact aided in the identification of nonparticipants and ineligible units.Conclusions:  The current survey indicates that differences in data between early and nonresponders can occur despite there being no demographic differences. Therefore, assessment of nonresponse bias based on demographic data alone would seem to be insufficient. Questionnaire survey research must first be based on sound sampling techniques, and then on achieving as high a response rate as possible using the many incentives available.
Assessment of risk factors for oral leukoplakia in West Virginia
Authors: Fisher Monica A. , Bouquot Jerry E. , Shelton Brent J. 
Published: January 2005

Abstract –  Objective:  To assess risk factors associated with oral leukoplakia in a US population with high use of smoked tobacco and smokeless tobacco.Methods:  The RJ Gorlin Leukoplakia Tissue Registry was used to identify individuals with oral leukoplakia in West Virginia, USA. This case–control study consisted of 90 cases with oral leukoplakia and 78 controls with periapical cysts. Univariate–univariable (one dependent variable and one independent variable) and univariate–multivariable (one dependent variable and multiple independent variables) logistic regression modeling quantified the association between oral leukoplakia and potential explanatory variables.Results:  Unadjusted measures of association indicate that those with oral leukoplakia were more likely to be older [odds ratio of crude: ORCrude=2.72; 95% confidence interval (CI): 1.45–5.11], more likely to currently use smokeless tobacco (ORCrude=3.16; 95% CI: 1.10–9.07), and more likely to currently use snuff (ORCrude=8.32; 95% CI: 1.83–37.80). Individuals currently using smokeless tobacco or currently using snuff were more likely to have oral leukoplakia [adjusted odds ratio, ORAdj=9.21 and 30.08; 95% CI: 1.49–57.00 and 2.67–338.48, respectively], after simultaneously adjusting for age, gender, currently using smoked tobacco, currently using alcohol daily, and dental prostheses use.Conclusions:  Generalizability is an issue when studying risk factors associated with oral leukoplakia because of geographical variations in the composition of smokeless tobacco (i.e. betel, lime, ash, and N‐nitrosamines) and cultural variations in the use of tobacco (i.e. reverse smoking). Snuff was the main smokeless tobacco product currently used in West Virginia, and was strongly associated with oral leukoplakia, after adjusting for potential explanatory variables.
The Controversy over the Protection of Motherhood and its Impact upon the Japanese Women's Movement
Authors: Tomida Hiroko 
Published: January 2005

AbstractThis article is an assessment of the bosei hogo ronsō (the controversy over the protection of motherhood) which developed between 1916 and 1919 among four female protagonists—Hiratsuka Raichō, Yosano Akiko, Yamakawa Kikue and Yamada Waka. It describes the origin and development of the controversy in the light of international and domestic social and political changes affecting women in Japan in the 1910s. It examines each protagonist's views on the rights and wrongs of the state protecting motherhood, and compares their positions. It also discusses the influence which Western feminists such as Olive Schreiner and Ellen Key had on the debate, and the conclusion which the debate reached. The article finally reviews the achievements and limitations of this key debate, and assesses the impact the controversy had on the Japanese women's movement.
The Major Discharge Events in the Paraguay River: Magnitudes, Source Regions, and Climate Forcings
Authors: Barros Vicente , Chamorro Lucas , Coronel Genaro , Baez Julián 
Published: January 2005

Abstract
The greatest discharges of the Paraguay River were studied using monthly series of Ladario, Brazil, at the outlet of the vast wetland of the Pantanal, and Asunción, Paraguay, at the middle Paraguay River outlet. Most of the major discharges at Asunción peaked between May and July, in phase with the annual maximum of the river discharges. They originated in the upper and middle Paraguay basins and were independent of the Pantanal output because their climate forcings were different from those of the Pantanal. In fact, most of the major discharge contributions from the upper and middle Paraguay basins occurred during El Niño (EN) periods, while at the Pantanal outlet they happened in neutral periods. The top discharge occurred during the autumn following the EN onset year. The composite of these cases has a tropospheric circulation that enhances the subtropical jet and the cyclonic vorticity advection over the Alto Paraná and the upper and middle Paraguay basins, favoring large positive anomalies in the precipitation field. Not all the major discharges were related to EN. Particularly, the major discharges that peaked in winter shared common features, despite their occurrence during EN, La Niña, or the neutral phases. Their April to August fields had an almost barotropic pattern at high latitudes with a deep cyclonic anomaly between 120° and 160°W and an anticyclonic anomaly over the southern tip of South America. This pattern is consistent with a northward shift of the synoptic perturbation tracks, which favors fields of positive precipitation anomalies over the Paraguay basin.
Climate Index Weighting Schemes for NWS ESP-Based Seasonal Volume Forecasts
Authors: Werner Kevin , Brandon David , Clark Martyn , Gangopadhyay Subhrendu 
Published: January 2005

Abstract
This study compares methods to incorporate climate information into the National Weather Service River Forecast System (NWSRFS). Three small-to-medium river subbasins following roughly along a longitude in the Colorado River basin with different El Niño–Southern Oscillation signals were chosen as test basins. Historical ensemble forecasts of the spring runoff for each basin were generated using modeled hydrologic states and historical precipitation and temperature observations using the Ensemble Streamflow Prediction (ESP) component of the NWSRFS.
Two general methods for using a climate index (e.g., Niño-3.4) are presented. The first method, post-ESP, uses the climate index to weight ensemble members from ESP. Four different post-ESP weighting schemes are presented. The second method, preadjustment, uses the climate index to modify the temperature and precipitation ensembles used in ESP. Two preadjustment methods are presented. This study shows the distance-sensitive nearest-neighbor post-ESP to be superior to the other post-ESP weighting schemes. Further, for the basins studied, forecasts based on post-ESP techniques outperformed those based on preadjustment techniques.
A Proposed Structure for Coupling Tiled Surfaces with the Planetary Boundary Layer
Authors: Best M. J. , Beljaars A. , Polcher J. , Viterbo P. 
Published: January 2005

Abstract
A generalized coupling is proposed between atmospheric models and surface schemes (land and ocean). A set of input and output variables is defined for this purpose in such a way that it can be used by many current and future models, including mosaic or tile schemes. The basic concept is to pass atmospheric variables from the lowest model level and their relation to corresponding fluxes to the surface scheme. The surface scheme returns the fluxes. In this framework, there is no need for the atmospheric model to have detailed information about the surface. Only the result of the surface computations is needed; namely, the fluxes, which are applied as a boundary condition. The equations for fully implicit coupling are derived, and the relevance for numerical stability is demonstrated. It is also shown that fully implicit coupling in a tile scheme leads to more robust results than partially implicit coupling.