bluuebunny/crossref_metadata_2025 huggingface dataset:
Eukaryotic Regulatory Element Conservation Analysis and Identification Using Comparative Genomics
Authors: Liu Yueyi , Liu X. Shirley , Wei Liping , Altman Russ B. , Batzoglou Serafim
Published: March 2004

Comparative genomics is a promising approach to the challenging problem of eukaryotic regulatory element identification, because functional noncoding sequences may be conserved across species from evolutionary constraints. We systematically analyzed known human andSaccharomyces cerevisiaeregulatory elements and discovered that human regulatory elements are more conserved between human and mouse than are background sequences. AlthoughS. cerevisiaeregulatory elements do not appear to be more conserved by comparison ofS. cerevisiaetoSchizosaccharomyces pombe, they are more conserved when compared with multiple other yeast genomes (Saccharomyces paradoxus, Saccharomyces mikatae, andSaccharomyces bayanus). Based on these analyses, we developed a sequence-motif-finding algorithm called CompareProspector, which extends Gibbs sampling by biasing the search in regions conserved across species. Using human–mouse comparison, CompareProspector identified known motifs for transcription factors Mef2, Myf, Srf, and Sp1 from a set of human-muscle-specific genes. It also discovered the NFAT motif from genes up-regulated by CD28 stimulation in T-cells, which implies the direct involvement of NFAT in mediating the CD28 stimulatory signal. UsingCaenorhabditis elegans–Caenorhabditis briggsaecomparison, CompareProspector found the PHA-4 motif and the UNC-86 motif. CompareProspector outperformed many other computational motif-finding programs, demonstrating the power of comparative genomics-based biased sampling in eukaryotic regulatory element identification.
Control of Yeast Filamentous-Form Growth by Modules in an Integrated Molecular Network
Authors: Prinz Susanne , Avila-Campillo Iliana , Aldridge Christine , Srinivasan Ajitha , Dimitrov Krassen , Siegel Andrew F. , Galitski Timothy
Published: March 2004

On solid growth media with limiting nitrogen source, diploid budding-yeast cells differentiate from the yeast form to a filamentous, adhesive, and invasive form. Genomic profiles of mRNA levels in Saccharomyces cerevisiae yeast-form and filamentous-form cells were compared. Disparate data types, including genes implicated by expression change, filamentation genes known previously through a phenotype, protein–protein interaction data, and protein–metabolite interaction data were integrated as the nodes and edges of a filamentation-network graph. Application of a network-clustering method revealed 47 clusters in the data. The correspondence of the clusters to modules is supported by significant coordinated expression change among cluster co-member genes, and the quantitative identification of collective functions controlling cell properties. The modular abstraction of the filamentation network enables the association of filamentous-form cell properties with the activation or repression of specific biological processes, and suggests hypotheses. A module-derived hypothesis was tested. It was found that the 26S proteasome regulates filamentous-form growth.
Evaluating the effectiveness of interactive computer tutorials for an undergraduate mathematical literacy course
Authors: Frith Vera , Jaftha Jacob , Prince Robert
Published: March 2004

This article describes a study of learning when students used interactive spreadsheet‐based computer tutorials in a mathematical literacy course. It foregrounds theories relating to the role of computer technology (and specifically spreadsheets) as a mediator for learning of mathematics. It outlines the application of quantitative methods involving pre‐ and post‐testing of students, both in the computer laboratory and in the lecture sessions, and discusses factors constraining the experimental design and the usefulness of the results. There are indications that the data reveal real differences between the learning experiences in the lecture sessions and the computer laboratories. It appears that in some respects the computer tutorials were more effective in conveying the concepts than the lecture sessions were. A method of analysing and representing the data, that tracks the extent of learning of concepts through the pre‐ and post‐tests, was developed. It allows for the performance of sub‐groups of students to be examined separately. This analysis shows that simple definitions of disadvantage (such as having English as a second language) are inadequate to account for the poor performance of students in the lower quartile.
Impacts of migratory behaviour on population structure in North Sea plaice
Authors: Hunter Ewan , Metcalfe J. D. , Arnold G. P. , Reynolds J. D.
Published: March 2004

Migration is widespread among marine fishes, yet little is known about variation in the migration of individuals within localities, and the consequences for spatial population structure. We tested the hypothesis that variation in the migratory behaviour among plaice (Pleuronectes platessaL.) in the North Sea could be explained by large‐scale differences in the speed and directions of the tidal streams, which the fish use as a transport mechanism.

We released 752 mature female plaice tagged with electronic data storage tags at eight locations with contrasting tidal flow properties between December 1993 and September 1999.

The experiment yielded 20 403 days of data from 145 plaice. Individual tags recorded depth and temperature for up to 512 days. The position of each fish was determined at intervals throughout the liberty period using the tidal location method.

The results show that the fish were segregated into three discrete feeding aggregations during the summer non‐breeding season. Two clusters were in warm, thermally mixed water in the eastern and western North Sea, respectively, and one was in deeper, cold, thermally stratified water to the north.

In the winter spawning period, fish from all three aggregations mixed together in the southern North Sea, and fish from the eastern and northern subunits spawned in the south‐eastern North Sea. The only fish that left the North Sea were western subunit plaice that visited spawning grounds in the eastern English Channel.

Our results re‐affirmed the major role of the tidal streams in the southern North Sea in structuring plaice dispersion, both by providing transport and guidance and by delimiting the extent of distribution due to thermal stratification during the summer. However, plaice from the northern North Sea did not use tidal stream transport.

These results confirm the prediction that large‐scale variation in migration behaviour can be explained in part by the tidal guidance and transport mechanisms available. They have also revealed features of spatial dynamics not observed previously from a century of conventional tagging experiments and illustrate how the study of individual fish can successfully define the migratory characteristics of populations.
Density‐dependent prophylaxis and condition‐dependent immune function in Lepidopteran larvae: a multivariate approach
Authors: Cotter S. C. , Hails R. S. , Cory J. S. , Wilson K.
Published: March 2004

The risk of parasitism and infectious disease is expected to increase with population density as a consequence of positive density‐dependent transmission rates. Therefore, species that encounter large fluctuations in population density are predicted to exhibit plasticity in their immune system, such that investment in costly immune defences is adjusted to match the probability of exposure to parasites and pathogens (i.e. density‐dependent prophylaxis).

Despite growing evidence that insects in high‐density populations show the predicted increase in resistance to certain pathogens, few studies have examined the underlying alteration in immune function. As many of these species show increased cuticular melanism at high densities, the aim of this study was to use a multivariate approach to quantify relative variation in the allocation of resources to immunity associated with both rearing density (solitary vs. crowded) and cuticular colour (pale vs. dark) in a phase‐polyphenic Lepidopteran species (Spodoptera littoralis Boisduval).

Relative to pale individuals, dark larvae (the high‐density phenotype) exhibited higher haemolymph and cuticular phenoloxidase (PO) activity and a stronger melanotic encapsulation response to an artificial parasite inserted into the haemocoel. However, they also exhibited lower antibacterial (lysozyme‐like) activity than pale larvae. Larval density per se had little effect on most of the immune parameters measured, though capsule melanization and antibacterial activity were significantly higher in solitary‐reared than crowded larvae.

Correcting for variation in larval body condition, as estimated by weight and haemolymph protein levels, had little effect on these results, suggesting that variation in immune function across treatment groups cannot be explained by condition‐dependence. These results are examined in relation to pathogen resistance, and the possibility of a trade‐off within the immune system is discussed.
Prevalence of apical periodontitis and frequency of root‐filled teeth in an adult Spanish population
Authors: Jiménez‐Pinzón A. , Segura‐Egea J. J. , Poyato‐Ferrera M. , Velasco‐Ortega E. , Ríos‐Santos J. V.
Published: March 2004

Aim  To estimate the prevalence of teeth with apical periodontitis (AP) and root‐filled teeth in an adult Spanish population.

Methodology  A total of 180 subjects, aged 37.1 ± 15.7 years, presenting as new patients to the Faculty of Dentistry, Seville, Spain, were examined. All participants underwent a full‐mouth radiographic survey (14 periapical radiographs). The frequency of root canal treatment and the periapical status of all teeth, using the periapical index (PAI) score, were assessed. An intraobserver agreement test on PAI scores produced a Cohen's kappa of 0.77 (substantial agreement). Results were analysed statistically using the Chi‐square test.

Results  Apical periodontitis in one or several teeth was found in 110 subjects (61.1% prevalence), and 73 (40.6% prevalence) had at least one root‐filled tooth. Among subjects with root‐filled teeth, 48 (65.8%) had AP affecting at least one root‐filled tooth. A total of 4453 teeth were examined, of these 186 (4.2%) had AP. The total number of root‐filled teeth was 93 (2.1%), of which 60 (64.5%) had AP. Among non‐root filled teeth, only 2.9% had AP. The prevalence of AP in connection with molar teeth was higher (5.5%) than for premolar (4.5%) and anterior teeth (3.2%; P < 0.01). More premolar and molar teeth were root‐filled (2.8 and 2.7%, respectively) than anterior teeth (1.3%; P < 0.01). The prevalence of AP increased with age.

Conclusions  The prevalence of AP in root‐filled and untreated teeth, and the frequency of root‐filled teeth were comparable to those reported in previous similar studies carried out in European countries. The prevalence of root‐filled teeth with AP was found to be higher compared to that demonstrated in other epidemiological studies.
Fraudulent management of digital endodontic images
Authors: Güneri P. , Akdeniz B. G.
Published: March 2004

Aim  To present examples of radiographic image reconstructions in endodontic treatment, to discuss the potential problems arising from the use of image processing software and to mention some current methods to prevent such counterfeit utilization of digital endodontic radiographs.

Summary  Conventional Ultra‐Speed periapical films of root canal treatment were digitized with a flatbed scanner (Umax Powerlook II, Umax Technologies, Inc., Taiwan). Digital images were altered with photoshop 6.0 software (Adobe Corporation, San Jose, CA, USA). Carious lesions, periapical pathoses, fake root canals and artificial fillings were created, and inadequate treatment was corrected by application of various image manipulation functions of the software.

Key learning points 

Digital endodontic images can be altered with image processing software.

The use of digital radiographic data inevitably raises concerns about security, reliability and the potential for fraud.
Effects of calcium hydroxide on physical and sealing properties of canal sealers
Authors: Hosoya N. , Kurayama H. , Iino F. , Arai T.
Published: March 2004

Aim  To investigate whether Ca(OH)2 in four different agents alters the physical properties (Exp. I) and sealing ability (Exp. II) of root canal sealers.

Experiment  (Exp. I) Calcipex® (Nippon Sika‐Yakuhin, Shimonoseki, Japan), Vitapex® (Neo‐Dental, Tokyo, Japan), Calkyl® (Showa Yakuhin, Tokyo, Japan), and Ca(OH)2 were used as Ca(OH)2 agents. Four sealers were tested for flow, working time, setting time, and film thickness: Canals® (Showa Yakuhin), Canals®‐N (Showa Yakuhin), Ketac™‐Endo (Espe, Seefeld, Germany), and Sealapex® (Kerr, Romulus, MI, USA). Each Ca(OH)2 agent was added to 10 vol.% of each sealer, and the mixture and controls without a Ca(OH)2 agent were tested according to ISO specifications. Measurements were compared using Student's t‐tests (P < 0.05). (Exp. II) After removing Ca(OH)2 agents applied to the root canals of 100 extracted human teeth, canals were filled with sealer. Controls were filled with each sealer without Ca(OH)2 agents. Sealing ability was evaluated using distance of dye penetration from the apices. Dye penetration data were compared using analysis of variance and post hoc Newman–Keuls test (P < 0.05).

Results  Ca(OH)2 agents influenced the physical properties of the sealers. Flow and setting time met ISO requirements, but film thickness and working time did not. Apical sealing ability of all four sealers was influenced by Ca(OH)2 agents. The sealing ability of Sealapex® improved with all Ca(OH)2 agents. The physical and sealing abilities varied among the other sealers.

Conclusions  Contact with Ca(OH)2 agents left on the canal wall caused considerable changes to the sealing ability of sealers.
The epidemiology of extrahepatic biliary atresia in New York State, 1983–98
Authors: Caton Alissa R. , Druschel Charlotte M. , McNutt Louise A.
Published: March 2004

The aetiology of biliary atresia, the leading cause of neonatal extrahepatic jaundice and the main indication for liver transplantation in children, is unknown. Recent research has focused on an infectious aetiology and the development of viral models in animals. The few published epidemiological studies report conflicting results for seasonal, geographical, and racial variations in incidence. In this study, New York State (NYS) Congenital Malformations Registry data from 1983 to 1998 were compared with resident live birth certificate data. County of residence, birth date, gestational age, birthweight, gender, maternal race and maternal age were extracted from the birth certificate data. Isolated and sequence cases were combined for analysis. Observed and expected numbers of cases were calculated by NYS region.

Overall, 369 biliary atresia cases were reported in the 16‐year study period, a rate of 0.85 [95% CI 0.76, 0.93] per 10 000 live births. Of these, 249 isolated/sequence cases were ascertained, a rate of 0.57 [95% CI 0.50, 0.64] per 10 000 live births. The rate ratio of biliary atresia in New York City (NYC) compared with other NYS was 2.19 [95% CI 1.69, 2.84]. Seasonal patterns varied by region with spring births at highest risk in NYC and September to November births at highest risk in other NYS. The rate ratio in black vs. white mothers was 1.94 [95% CI 1.48, 2.54]. Birthweight and gestational age were associated with biliary atresia with preterm low‐birthweight infants at highest risk [RR 3.24, 95% CI 2.20, 4.76]. The association of isolated/sequence biliary atresia with season, preterm birth, and low birthweight in our study supports an infectious disease hypothesis.
Recruitment for a community‐based study of early pregnancy: the Right From The Start study
Authors: Promislow Joanne H. E. , Makarushka Christina M. , Gorman Jessica R. , Howards Penelope P. , Savitz David A. , Hartmann Katherine E.
Published: March 2004

Despite the high incidence of spontaneous abortion, little is known about its causes, in part because of the challenge of assembling a large cohort of women in early pregnancy for prospective study. We describe the effectiveness of recruitment strategies used in Right From The Start (RFTS), a prospective, community‐based study of spontaneous abortion. Between December 2000 and September 2002, 803 pregnant women enrolled in RFTS, 103 of whom were recruited while trying to conceive. The mean gestational age at enrolment was 52 days, with 25% of the cohort enrolling before 6 completed weeks’ gestation. Participants recruited directly from the community typically enrolled earlier in their pregnancies (mean of 44 days) and accounted for 24% of the total cohort and 83% of all participants who were recruited while trying to conceive. Posting brochures in drug stores and targeted mailings to new homeowners were the most effective community recruitment strategies. Recruitment at private and public prenatal care sites accounted for 57% and 19% of the participants respectively. Recruitment from public clinics required direct contact by RFTS staff and yielded women who enrolled at later gestational ages (mean of 58 days), but was valuable for inclusion of minorities and lower income women with less favourable health behaviours. Although intensive, diverse efforts were required, when recruitment efforts were maximised, we successfully recruited over 10% of the estimated number of pregnant women in the community.
The Arabidopsis FtsH metalloprotease gene family: interchangeability of subunits in chloroplast oligomeric complexes
Authors: Yu Fei , Park Sungsoon , Rodermel Steven R.
Published: March 2004

The Arabidopsis At filamentation temperature sensitive (FtsH) metalloprotease gene family comprises 12 members (AtFtsH1–AtFtsH12), including three pairs of closely related genes that are targeted to chloroplasts (AtFtsH2 and AtFtsH8; AtFtsH1 and AtFtsH5; and AtFtsH7 and AtFtsH9). Mutations in AtFtsH5 (var1) and AtFtsH2 (var2) give rise to variegated plants with green‐ and white‐sectored leaves. Cells in the green sectors contain morphologically normal chloroplasts, whereas cells in the white sectors are blocked in chloroplast biogenesis. A major question is how chloroplasts arise in cells that have a mutant genotype. We have found by two‐dimensional (2‐D) green gel and gel filtration analyses that AtFtsH2/VAR2 forms oligomeric complexes. Two bands in the 2‐D green gels that correspond to AtFtsH5/VAR1 + AtFtsH1 and AtFtsH2/VAR2 + AtFtsH8 have been identified, and these bands are coordinately reduced in amount in var1 and var2 thylakoids that lack AtFtsH5/VAR1 and AtFtsH2/VAR2, respectively. These reductions are not because of alterations in transcript abundance. Overexpression of AtFtsH8 in var2‐4 (a putative null allele) normalizes the variegation phenotype of the mutant and restores the two bands to their wild‐type levels. These results suggest that AtFtsH8 is interchangeable with AtFtsH2/VAR2 in AtFtsH‐containing oligomers, and that the two proteins have redundant functions. Consistent with this hypothesis, AtFtsH2 and AtFtsH8 have similar expression patterns, as monitored by promoter–β‐glucuronidase (GUS) fusion and RT‐PCR experiments. Based on our findings, we propose that AtFtsH1, AtFtsH2/VAR2, AtFtsH5/VAR1, and AtFtsH8 interact to form oligomeric structures, and that subunit stoichiometry is controlled post‐transcriptionally in var1 and var2, perhaps by turnover. A threshold model is presented to explain the pattern of variegation in var2 in which AtFtsH8 provides a compensating activity in the green sectors of the mutant.
Microarray analysis of chromatin‐immunoprecipitated DNA identifies specific regions of tobacco genes associated with acetylated histones
Authors: Chua Yii Leng , Mott Ellie , Brown Anthony P. C. , MacLean Daniel , Gray John C.
Published: March 2004

The acetylation states of histones present on the upstream, promoter, coding or intronic regions of 88 tobacco genes were examined with chromatin immunoprecipitation (ChIP) experiments using antibodies that recognised acetylated histone H4. The DNA sequences enriched in the immunoprecipitates were amplified by ligation‐mediated PCR, labelled with Cy‐dUTP and hybridised to DNA microarrays. In green tobacco shoots, histone H4 acetylation was localised to 300–600‐bp sequences in the promoters or coding regions of 31 genes, or occurred extensively over several kilobase‐pair regions containing the upstream, promoter and/or coding regions of 25 genes. Genes associated with high histone H4 acetylation levels at promoters were actively expressed, whereas genes depleted in acetylated histone H4 were non‐transcribed or expressed at very low levels, suggesting a correlation between histone H4 acetylation and gene activity. Trichostatin A (TA), an inhibitor of histone deacetylases (HDAs), did not alter histone H4 acetylation states globally but increased acetylation levels at specific tobacco sequences, suggesting that HDAs are targeted to particular nucleosomes. Genes that were upregulated by TA were associated with increased histone H4 acetylation at promoter or coding regions, indicating that acetylation of histones on coding regions may activate transcription. Increased histone H4 acetylation leading to elevated expression was observed on genes with diverse functions, suggesting that histone H4 acetylation is involved in regulation of many plant processes.
Pleasure Reading: Associations Between Young Women's Sexual Attitudes and their Reading of Contemporary Women's Magazines
Authors: Kim Janna L. , Ward L. Monique
Published: March 2004

Associations between magazine use and sexual attitudes were explored among 205 female college students. Measures assessed reading levels of adult-focused (e.g., Cosmopolitan) and teen-focused (e.g., Seventeen) contemporary women's magazines, reading motivations, sexual attitudes, and femininity ideologies. Frequent reading of adult-focused magazines was associated with weaker support of sexual stereotypes about men, of a view that equates sex with risk, and of women's reports of self-censorship. In contrast, frequent reading of teen-focused magazines was associated with stronger endorsement of male sexual stereotypes. In addition, reading women's magazines intently for sex advice was associated with stronger support of both male sexual stereotypes and a sexually assertive female role. Implications are discussed in terms of both relevant media theories and of magazines as sources of sexual scripts.
Fluid transport across cultured rat alveolar epithelial cells: a novel in vitro system
Authors: Fang Xiaohui , Song Yuanlin , Zemans Rachel , Hirsch Jan , Matthay Michael A.
Published: March 2004

Previous studies have used fluid-instilled lungs to measure net alveolar fluid transport in intact animal and human lungs. However, intact lung studies have two limitations: the contribution of different distal lung epithelial cells cannot be studied separately, and the surface area for fluid absorption can only be approximated. Therefore, we developed a method to measure net vectorial fluid transport in cultured rat alveolar type II cells using an air-liquid interface. The cells were seeded on 0.4-μm microporous inserts in a Transwell system. At 96 h, the transmembrane electrical resistance reached a peak level (1,530 ± 115 Ω·cm2) with morphological evidence of tight junctions. We measured net fluid transport by placing 150 μl of culture medium containing 0.5 μCi of 131I-albumin on the apical side of the polarized cells. Protein permeability across the cell monolayer, as measured by labeled albumin, was 1.17 ± 0.34% over 24 h. The change in concentration of 131I-albumin in the apical fluid was used to determine the net fluid transported across the monolayer over 12 and 24 h. The net basal fluid transport was 0.84 μl·cm−2·h−1. cAMP stimulation with forskolin and IBMX increased fluid transport by 96%. Amiloride inhibited both the basal and stimulated fluid transport. Ouabain inhibited basal fluid transport by 93%. The cultured cells retained alveolar type II-like features based on morphologic studies, including ultrastructural imaging. In conclusion, this novel in vitro system can be used to measure net vectorial fluid transport across cultured, polarized alveolar epithelial cells.
New replicable anxiety-related measures of wall vs. center behavior of mice in the open field
Authors: Lipkind Dina , Sakov Anat , Kafkafi Neri , Elmer Gregory I. , Benjamini Yoav , Golani Ilan
Published: March 2004

Anxiety is a widely studied psychiatric disorder and is thought to be a complex and multidimensional phenomenon. Sensitive behavioral discrimination of animal models of anxiety is crucial for the elucidation of the behavioral components of anxiety and the physiological processes that mediate them. Commonly used behavior paradigms of anxiety usually include only a few automatically collected measures; these do not exhaust the behavioral richness exhibited by animals, thus perhaps missing important differences between preparations. The aim of the present study was to expand the repertoire of automatically collected measures in a classical test of anxiety: behavior in relation to the wall in the open field. We present an algorithm, based on the Software for the Exploration of Exploration strategy, which automatically partitions the mouse path into intrinsically defined patterns of movement near the wall and in the center. These patterns are used to design new end points, which provide an articulated description of various aspects of behavior near the wall and in the center. Sixteen new end points were designed with data from C57BL/6J and DBA/2J mice tested in three laboratories. The strain differences in all end points were evaluated on another data set to assess their validity and were found to remain stable. Ten of the sixteen end points were found to discriminate between the two strains in a replicable manner. The entire set of end points can be used on various genetic and pharmacological models of anxiety with good prospects of providing fine discrimination in a replicable manner.
Management of personality disorders in acute in-patient settings. Part 2: Less-common personality disorders
Authors: Fagin Leonard
Published: March 2004

Less-common personality disorders affecting patients admitted to in-patient units are discussed in some detail. These disorders are rarely a direct cause of admission, but they are often associated with other Axis I disorders and can therefore be obstacles to successful treatment. A knowledge of the clinical picture and underlying dynamics and an awareness of countertransference feelings that these patients are likely to provoke can enhance therapeutic alliances and improve the chance of effective care plans.
Improving the physical health of long-stay psychiatric in-patients
Authors: Cormac Irene , Martin David , Ferriter Michael
Published: March 2004

Research evidence has shown that morbidity and mortality rates are higher in psychiatric patients than in the general population. This article describes factors that affect the physical health of psychiatric patients living in institutions and the steps that can be taken to review, monitor and improve their physical health. The physical health care of long-stay patients should reach the same standards as those expected in the general population.
Out-of-borough placements for people with learning disabilities
Authors: Jaydeokar Sujeet , Piachaud Jack
Published: March 2004

All people with learning disabilities should be able to choose from a variety of residential placements as a way of achieving greater community integration. However, many are still placed away from their borough of origin, resulting in complex consequences for them, and their families and for clinicians. This article explores the nature of the problem, defining the current issues, and examining the role of the stakeholders and the implications for psychiatrists working in this field.
Fictional narrative and psychiatry
Authors: Oyebode Femi
Published: March 2004

This article addresses how mental illness and psychiatry are dealt with in fictional narrative. The starting point is Charlotte Bronte's novel Jane Eyre. The characterisation of madness in that novel provides the basis for exploring how the physical and psychological differences of mentally ill people are portrayed, and how violence and the institutional care of people with mental illnesses are depicted. It is also argued that the fact that in Jane Eyre, Bertha Mason, the madwoman in the attic, is rendered voiceless is not accidental but emblematic of the depiction of mentally ill people in fiction. A number of novels are used to illustrate these issues.
Estrogen Modulation of G‐Protein‐Coupled Receptor Activation of Potassium Channels in the Central Nervous System
Authors: KELLY MARTIN J. , QIU JIAN , RØNNEKLEIV OLINE K.
Published: March 2004

Abstract: Estrogen rapidly alters the excitability of hypothalamic neurons that are involved in regulating numerous homeostatic functions including reproduction, stress responses, feeding, and motivated behaviors. Neurosecretory neurons, such as gonadotropin‐releasing hormone (GnRH) and dopamine neurons, and local circuitry neurons, such as pro‐opiomelanocortin (POMC) and γ‐aminobutyric acid (GABA) neurons, are among those involved. We have identified membrane‐initiated, rapid‐signaling pathways through which 17β‐estradiol (E2) alters synaptic responses in these neurons using whole‐cell patch recording in hypothalamic slices from ovariectomized female guinea pigs. E2 rapidly uncouples μ‐opioid and GABAB receptors from G‐protein‐gated inwardly rectifying K+ (GIRK) channels in POMC and dopamine neurons as manifested by a reduction in the potency of μ‐opioid and GABAB receptor agonists to activate these channels. These effects are mimicked by the selective E2 receptor modulators raloxifene and 4OH‐tamoxifen, the membrane impermeable E2‐bovine serum albumin (BSA), but not by 17α‐estradiol. Furthermore, the anti‐estrogen ICI 182,780 antagonizes these rapid effects of E2. Inhibitors of phospholipase C, protein kinase C, and protein kinase A block the actions of E2, indicating that the E2 receptor is G‐protein‐coupled to activation of this cascade. Conversely, estrogen enhances the efficacy of α1‐adrenergic receptor agonists to inhibit apamin‐sensitive small‐conductance, Ca2+‐activated K+ (SK) currents in preoptic GABAergic neurons; it does so in both a rapid and sustained fashion. Finally, we observed a direct, steroid‐induced hyperpolarization of GnRH neurons. These findings indicate that E2 can modulate K+ channels in hypothalamic (POMC, dopamine, GABA, GnRH) neurons that are involved in regulating numerous homeostatic functions through multiple intracellular signaling pathways.
Regulation of Gene Expression in the Developing Midbrain by Estrogen: Implication of Classical and Nonclassical Steroid Signaling
Authors: BEYER CORDIAN , PAWLAK JUSTYNA , BRITO VERONICA , KAROLCZAK MAGDALENA , IVANOVA TATIANA , KÜPPERS EVA
Published: March 2004

Abstract: Estrogen plays an important role during midbrain development. This is indicated by the presence of nuclear estrogen receptors and the transient expression of the estrogen‐forming enzyme aromatase. A number of recent studies have shown that estrogen promotes the differentiation and survival, as well as physiological performance, of midbrain dopaminergic cells. In addition, we have reported that both ways of cellular estrogen signaling (classical and nonclassical) as well as interactions with nonneuronal target cells are involved in the transmission of intra‐ and intercellular estrogen effects in this brain region. This study provides additional evidence that (i) estrogen is capable of regulating gene expression in cultured embryonic neurons and astrocytes differently and (ii) both signaling mechanisms, i.e., classically through nuclear receptors and nonclassically through the stimulation of membrane‐estrogen receptors, which are coupled to distinct intracellular signal transduction cascades, contribute diversely to gene regulation. These data reveal a high degree of complexity of estrogen action at the genomic level in the developing brain. Further studies are warranted to unravel the exact contribution of the differently regulated genes for developmental estrogen action.
In Vivo Effects of Estrogen on Human Brain
Authors: CUTTER WILLIAM J. , CRAIG MICHAEL , NORBURY RAY , ROBERTSON DENE M. , WHITEHEAD MALCOLM , MURPHY DECLAN G.
Published: March 2004

Abstract: Age‐related brain disorders such as Alzheimer's disease (AD) are becoming increasingly prevalent. Estrogen replacement therapy (ERT) has shown potential both as a preventive measure and treatment for such disorders. Good evidence from basic science demonstrates that estrogen has multiple protective effects on neurons and neurotransmitter systems, and the effects of ERT can be demonstrated on the human brain using techniques such as functional neuroimaging. However, the evidence for estrogen's having a clinical role in the treatment and prevention of neuropsychiatric disorders is not well established. In this article we review research into the effects of estrogen on the human brain and we consider the role for ERT as a therapeutic tool.
Seasonal Regulation of Reproductive Activity in Sheep
Authors: THIERY JEAN‐CLAUDE , MALPAUX BENOIT
Published: March 2004

Abstract: Sheep in temperate latitudes are seasonal breeders. In female sheep, ovarian activity decreases during the anestrous period due to modification of secretion of luteinizing hormone (LH). The seasonal changes in the hormonal LH pattern mainly reflect an increase in the brain responsiveness to the negative feedback exerted by estradiol during long days (LD) on the frequency of pulsatile LH secretion, under neurohormonal GnRH control. The resulting seasonal inhibition of LH secretion mainly involves the activation of dopaminergic systems by E2, which in turn inhibits the GnRH cells from the preoptico‐hypothalamic structures. The increased responsiveness of the brain during LD could lead to increased expression of central E2 receptors. In addition, our study shows that steroid access to the brain could be modulated by photoperiodism, thus increasing the availability of steroids to the nervous structures during LD.
The Activation of Birdsong by Testosterone
Authors: BALL GREGORY F. , CASTELINO CHRISTINA B. , MANEY DONNA L. , APPELTANTS DIDIER , BALTHAZART JACQUES
Published: March 2004

Abstract:Birdsong is a species‐typical stereotypic vocalization produced in the context of reproduction and aggression. Among temperate‐zone songbirds, it is produced primarily by males, and its frequency and quality are enhanced by the presence of the gonadal steroid hormone testosterone in the plasma. In the brain, the effects of testosterone on song behavior involve both estrogenic and androgenic metabolites of testosterone that are locally produced and act via their cognate receptors. Androgen, and in some cases estrogen, receptors are present in many specialized forebrain song control nuclei. Testosterone can regulate catecholamine steady‐state levels and turnover in these song control regions. Tracing studies combined with immunocytochemistry for tyrosine hydroxylase (a marker of catecholamine synthesis) reveal several catecholamine cell groups that project to forebrain song control nuclei. These brain areas also express the mRNA for either androgen receptors or estrogen receptor alpha, and androgens enhance the expression of tyrosine hydroxylase. Dopaminergic cell groups that project to song nuclei express the protein product of the immediate early genefosin association with the production of territorial song. Thus, testosterone may be acting on song behavior via these ascending catecholamine cell groups. Chemical lesioning studies suggest that noradrenergic projections to the song system are involved in the latency to produce song and the ability to discriminate conspecific from heterospecific song. The song control circuit may thus be modulated in significant ways via the androgen regulation of forebrain catecholamine systems.
Progestin Receptors
Authors: BLAUSTEIN JEFFREY D.
Published: March 2004

Abstract: Although it originally was believed that neuronal steroid hormone receptors require binding to cognate ligand for activation, more recent evidence suggests that the receptors can be activated indirectly by other compounds, such as neurotransmitters and growth factors, acting through their own membrane receptors and specific intracellular signaling pathways. For example, as is the case with facilitation of sexual behavior by progesterone, facilitation of sexual behavior by D1/D5 dopamine receptor agonists is blocked by disruption of progestin receptors. Therefore, some dopamine agonists facilitate sexual behavior at least in part by a progestin receptor‐dependent mechanism, as does progesterone. This “ligand‐independent activation” of neuronal progestin receptors is not limited to dopamine agonists; a variety of other compounds, as well as mating stimulation, facilitate sexual receptivity by a progestin receptor‐dependent process. Steroid hormone receptors also can be regulated by afferent input in another way. Various neurotransmitters upregulate or downregulate steroid hormone receptors in some neurons. This, in turn, presumably confers greater or decreased sensitivity to the particular factors that can activate the particular steroid receptor in those particular neurons. Therefore, steroid hormones are but one class of factors that can regulate and activate steroid hormone receptors. Some additional factors that activate steroid hormone receptors have been identified, as have some factors that can regulate concentrations of receptors. Relatively little is known at this time about the range of neurotransmitters, humoral factors, and intracellular signaling pathways that are involved.
Steroid Effects on Glial Cells
Authors: DE NICOLA ALEJANDRO F. , LABOMBARDA FLORENCIA , GONZALEZ SUSANA L. , DENISELLE MARIA CLAUDIA GONZALEZ , GUENNOUN RACHIDA , SCHUMACHER MICHAEL
Published: March 2004

Abstract: Repair of damage and recovery of function are fundamental endeavors for recuperation of patients and experimental animals with spinal cord injury. Steroid hormones, such as progesterone (PROG), show regenerative and myelinating properties following injury of the peripheral and central nervous system. In this work, we studied PROG effects on glial cells of the normal and transected (TRX) spinal cord, to complement previous studies in motoneurons. Both neurons and glial cells expressed the classical PROG receptor (PR), suggesting that genomic mechanisms participated in PROG action. In TRX rats, PROG treatment stimulated the number of NADPH‐diaphorase (nitric oxide synthase) active astrocytes, whereas the number of astrocytes expressing the glial fibrillary acidic protein (GFAP) was stimulated in control but not in TRX rats. PROG also stimulated the immunocytochemical staining for myelin‐basic protein (MBP) and the number of oligodendrocyte precursor cells expressing the chondroitin sulfate proteoglycan NG2 in TRX rats. In terms of beneficial or detrimental consequences, these PROG effects may be supportive of neuronal recuperation, as shown for several neuronal functional parameters that were normalized by PROG treatment of spinal cord injured animals. Thus, PROG effects on glial cells go in parallel with morphological and biochemical evidence of survival of damaged motoneurons.
Synthesis and Luminescent Properties of 2-Phenyl-5-{4[2-(6-substituent-2H-benz[de]isoquinoline-1,3(2H)-dione-2-yl) polymethano-]amino-}phenyl-1,3,4-oxadiazole
Authors: Ni Weijuan , Su Jianhua , Chen Kongchang , Tian He
Published: March 2004

Several new derivatives of 1,8-naphthalimide, which are connected with 1,3,4-oxadiazole via a covalent bond, have been synthesized. We have investigated the electroluminescent (EL) device fabricated with these new compounds. In these compounds 1,3,4-oxadiazole moiety facilitates the electron injection from the electrode and transfers its excited energy to 1,8-naphthalimide which acts as an emitting center. Greenish yellow EL peaked at 532 nm with a maximum luminous efficiency of 0.43 lm/W was observed.
Stable and Active AlPO4 Catalyst for Decomposition of CCl2F2
Authors: Takita Yusaku , Li Gong-Liang , Matsuzaki Rie , Wakamatsu Hironori , Nishiguchi Hiroyasu , Moro-oka Yoshihiko , Ishihara Tatsumi
Published: March 2004

CCl2F2 was decomposed to CO2 at 350–450 °C in the presence of water vapor and O2 over AlPO4 calcined at 1000 °C. CCl2F2 conversion slightly decreased at initial 50 h and then took a steady value. AlPO4 was not fluorinated during 1000 h reaction at 400 °C.
Reactions of Molybdenum(V)porphyrins with Phenol Derivatives Involving Parallel Inner and Outer Sphere Electron Transfer
Authors: Kurihara Masato , Saito Ikuko , Morinaga Yoko , Matsuda Yoshihisa
Published: March 2004

Reactions of oxoethoxomolybdenum(V)porphyrins and substituted phenols were investigated by UV-vis absorption spectra. Ligand substitution or reduction of the metal center proceeded depending on the steric repulsion between the substituents of the phenols and the porphyrin skeletons. Proton transfer from the phenols to the axial ligand of the molybdenumporphyrin initiated the reactions. Parallel outer sphere and inner electron transfer proceeded parallel in the reduction of the molybdenum center.
A Novel Synthesis of Spirocyclopropenes from the Haloallene Derivatives with Alkanethiolate Ions
Authors: Toda Takashi , Kuwana Masahiro , Ohhashi Yoshitaka , Yoshida Masaaki
Published: March 2004

Reactions of 1-bromo-1-substituted-2-(9-fluorenylidene)ethenes with alkanethiolate ions gava spiro[1-alkylthiocyclopropene-3,9′-fluorenes]. The bromoallene derived from 2,3-diphenylindene also afforded the corresponding spirocyclopropene compound.
Theoretical Prediction of the 31P NMR Chemical Shift of the Hexa-Coordinate Phosphorus Intermediate for the Phosphoryl Ester Exchange and N→O Migration Reactions of Dimethyloxyphosphoryl-Threonine
Authors: Zhan Chang-Guo , Iwata Suehiro
Published: March 2004

Ab initio GIAO magnetic shielding calculations have been carried out on the hexa-coordinate phosphorus intermediate and the corresponding reactant and product for the N→O migration reaction of dimethyloxyphosphoryl-threonine. The calculated results lead us to predict that the 31P NMR chemical shift of the hexa-coordinate phosphorus intermediate is −138 ppm, while the 31P chemical shifts of the corresponding reactant and product are 4.9 ppm and −6.6 ppm, respectively.
A Simple and Efficient Synthesis of Di-, Tri-, and Tetraferrocenylarenes
Authors: Iyoda Masahiko , Kondo Terumasa , Okabe Toshitaka , Matsuyama Haruo , Sasaki Shigeru , Kuwatani Yoshiyuki
Published: March 2004

A series of di-, tri-, and tetraferrocenylarenes were synthesized by using the nickel- and palladium-catalyzed cross coupling reactions of ferrocenylzinc chloride with the corresponding di-, tri-, and tetrahalogenoarenes. Redox properties of these ferrocenylarenes were studied by cyclic voltammetry in order to examine the intramolecular interaction between the ferrocenyl substituents.
Electrochemical Syntheses and Electrochromic Properties of Chromium Cyanide Magnetic Thin Films
Authors: Sato Osamu , Gu Zhongze , Etoh Hiroyuki , Ichiyanagi Jun-ichi , Iyoda Tomokazu , Fujishima Akira , Hashimoto Kazuhito
Published: March 2004

Electrochemical preparation method and electromic properties of the mixed valence chromium cyanide thin film, which is one of the ferrimagnet with highest critical temparature (Tc) among molecule-based magnets, were described. The difference in the ability of the ligand substitution reaction between CrII and CrIII was utilized to synthesize the prussian blue analogs. The obtained magnetic material exhibited an excellent electrochromic properties. This indicates the compound has a potential for future display devices, as well as tunable molecule-based magnetic devices.
Catalytic Asymmetric Addition Reaction of Dialkylzinc to Nitrone Utilizing Tartaric Acid Ester as a Chiral Auxiliary
Authors: Ukaji Yutaka , Shimizu Yuuko , Kenmoku Yuuichi , Ahmed Alauddin , Inomata Katsuhiko
Published: March 2004

The catalytic asymmetric addition reaction of dialkylzinc to carbon-nitrogen double bond in 3,4-dihydroisoquinoline N-oxide derivatives was achieved by utilizing a catalytic amount of dicyclopentyl (R,R)-tartrate to afford the corresponding (S)-hydroxylamines in high optical yields up to 94% ee.
Three-dimensional Cage-like Polycyanopolycadmate Network Accommodating Werner Complexes; The Crystal Structure of [Cd(dien)2]·[Cd2(CN)3(dien)2]·[Cd8(CN)19]·3H2O (dien = (H2N(CH2)2)2NH, diethylenetriamine)
Authors: Kurihara Hiroyuki , Nishikiori Shin-ichi , Iwamoto Toschitake
Published: March 2004

An anionic three-dimensional network host [Cd8(CN)19]3− enclathrates a cationic mononuclear Cd complex guest [Cd(dien)2]2+, and a dinuclear Cd complex guest [Cd2(CN)3(dien)2]+, to form a novel inclusion compound [Cd(dien)2]·[Cd2(CN)3(dien)2]·[Cd8(CN)19]·3H2O (dien = (H2N(CH2)2)2NH, diethylenetriamine).
Electrocatalytic Reduction of Dioxygen in the Presence of N,N′-Dipentyl Viologen
Authors: Oh Mi-Kyung , Okajima Takeyoshi , Kitamura Fusao , Lee Chi-Woo , Tokuda Koichi , Ohsaka Takeo
Published: March 2004

An excellent electrocatalysis of N,N′-dipentyl viologen, which is based on not the dissolved species but the adsorbed one, has been observed for the electroreduction of O2 to H2O2 at glassy carbon electrode in neutral aqueous media. The rate constant for the catalytic reaction was estimated to be ca.106∼107 M−1s−1 based on cyclic and hydrodynamic voltammetry.
A Novel Dinuclear Iridium(III) Complex with a Bridging Disulfide Bond. Conversion of Coordinated Thiolato to Coordinated Bridging Disulfide by Acid Oxidation
Authors: Konno Takumi , Miyashita Yoshitaro , Okamoto Ken-ichi
Published: March 2004

Treatment of fac(S)-[Ir(aet)3] (aet = 2-aminoethanethiolate) with acid in water gave a novel dinuclear Ir(III) complex, [Ir2(aet)4(cysta)]2+ (cysta = cystamine), in which two octahedral Ir(III) units are linked by a coordinated disulfide bond.
Loop Formation of Au Nanopaticles Adsorbed on Langmuir Monolayers
Authors: Kawai Takeshi , Watanabe Tomoyuki
Published: March 2004

A hybrid monolayer of Au nanoparticles and dioctadecyl-dimethylammonium chloride (DODAC) was formed at the air–water interface. The Au nanoparticles were found to form loop structures. The loops were 0.1–1 μm in size with a width of around 5 nm, and consisted of single particle strings. The loop formation depended on the density of the DODAC monolayers, but not on the size distribution of the particles.
An All-solid-state Lithium Battery with Sulfur as Positive Electrode Materials
Authors: Machida Nobuya , Shigematsu Toshihiko
Published: March 2004

An all-solid-state lithium battery was assembled with sulfur as positive electrode materials and with an inorganic solid electrolyte a-60Li2S·40SiS2 (mol %). The all-solid-state lithium battery showed successive reversibility with large specific capacity. The specific capacity calculated on the base of the mass of sulfur was more than 1000 mA·h·g−1.
A Facile and Novel Route to 99mTc-labeled Antimony Sulfide Nanocolloid
Authors: Park Sang Hyun , Choi Sang Mu , Gwon Hui Jeong , Park Kyung Bae
Published: March 2004

99mTc-labeled antimony sulfide nanocolloid was prepared by a new labeling method that involves room temperature reconstitution with Na99mTcO4. Transmission electron microscope showed that the mean particle size was estimated to be mostly 7–15 nm. The labeling yield of 99mTc-Sb2S3 was more than 99%. The stability of the labeled product was studied at room temperature and it was found to be excellent.
Structures and Magnetic Properties of Organic Biradical Compounds with an Aromatic Core and Long Alkyl Groups
Authors: Amano Takamitsu , Akutsu Hiroki , Yamada Jun-ichi , Nakatsuji Shin’ichi
Published: March 2004

Organic biradical compounds having a biphenyl or naphthalene core and long alkyl groups with TEMPO (2,2,6,6-tetramethyl-1-piperidinyloxy) radicals at their ends were found to show moderately strong antiferromagnetic interactions, being based on the singlet-triplet model. The behavior could be understood by considering the structures as being assembled in a “hand-in-hand” fashion.