bluuebunny/crossref_metadata_2025 huggingface dataset:
Expression of Clock and Clock-Driven Genes in the Rat Suprachiasmatic Nucleus during Late Fetal and Early Postnatal Development
Authors: Kováčiková Zuzana , Sládek Martin , Bendová Zdenka , Illnerová Helena , Sumová Alena
Published: April 2006

The SCN as a site of the circadian clock itself exhibits rhythmicity. A molecular clockwork responsible for the rhythmicity consists of clock genes and their negative and positive transcriptional-translational feedback loops. The authors’ previous work showed that rhythms in clock gene expression in the rat SCN were not yet detectable at embryonic day (E) 19 but were already present at postnatal day (P) 3. The aim of the present study was to elucidate when during the interval E19-P3 the rhythms start to develop in clock gene expression and in clock-controlled, namely in arginine-vasopressin (AVP), gene expression. Daily profiles of Per1, Per2, Cry1, Bmal1, and Clock mRNA and of AVP heteronuclear (hn) RNA as an indicator of AVP gene transcription were assessed in the SCN of fetuses at E20 and of newborn rats at P1 and P2 by the in situ hybridization method. At E20, formation of a rhythm in Per1 expression was indicated, but no rhythms in expression of other clock genes or of the AVP gene were detected. At P1, rhythms in Per1, Bmal1, and AVP and a forming rhythm in Per2 but no rhythm in Cry1 expression were present in the SCN. The Per1 mRNA rhythm was, however, only slightly pronounced. The Bmal1 mRNA rhythm, although pronounced, exhibited still an atypical shape. Only the AVP hnRNA rhythm resembled that of adult rats. At P2, marked rhythms of Per1, Per2, and Bmal1 and a forming rhythm of Cry1, but not of Clock, expression were present. The data suggest that rhythms in clock gene expression for the most part develop postnatally and that other mechanisms besides the core clockwork might be involved in the generation of the rhythmic AVP gene expression in the rat SCN during early ontogenesis.
Circadian Rhythms in Murine Pups Develop in Absence of a Functional Maternal Circadian Clock
Authors: Jud Corinne , Albrecht Urs
Published: April 2006

A genetic approach was used to investigate whether the emergence of circadian rhythms in murine pups is dependent on a functional maternal clock. Arrhythmic females bearing either the mPer1Brdm1/Per2Brdm1 or mPer2Brdm1/Cry1-/- double-mutant genotype were crossed with wild-type males under constant darkness. The heterozygous offspring have the genetic constitution for a functional circadian clock. Individual pups born to arrhythmic mPer1Brdm1/Per2Brdm1 and mPer2Brdm1/Cry1-/- mothers in constant darkness without external zeitgeber developed normal circadian rhythms, but their clocks were less synchronized to each other compared to wild-type animals. These findings indicate that development of circadian rhythms does not depend on a functional circadian clock in maternal tissue, extending previous findings obtained from pups born to SCN-lesioned mothers.
Reflecting on Resistance
Authors: Sen Atreyee
Published: April 2006

This article analyses the power of peripheral urban spaces in the creation and dissemin-ation of a culture of female militancy. I show how poor women in the Bombay slums, by affiliating themselves with the aggressive Shiv Sena movement, came to violently control a range of physical, material and social spaces, in the process moving away from positions of subordination to occupy roles that allowed them to affect the male exercise of authority. I explore the importance of women's oral narratives by analysing the stories of migrant Shiv Sena women and their crippling encounters with a harsh slum life. The slum became a complex space that redefined and reconceptualised social groupings, and migration and relocation of unemployed people created new social and kinship networks. While sustaining a façade of being structurally muted within such an environment of constant transition, my ethnography illustrates how women (over two overlapping generations) tacitly and explicitly resisted naturalising discourses on femininity and ‘the home’. I argue that slum women strategically chose to infuse their physical environments with the threat of conflict, as women's presence in (and patrolling of) these contested urban spaces became a source of real and symbolic power.
Labouring to Love
Authors: Vincent Louise , McEwen Caryn
Published: April 2006

South Africa is 10 years into its new democratic order. An aspect of the country's political transformation has been an official political commitment to gender trans-formation. While great strides have been made towards greater gender equality at the institutional and legal level of society, the present article suggests that highly unequal power relations between men and women continue to be perpetuated in unexpected ways among those whom we would most expect to be capable of resistance. This paper is about how subtle yet deeply embedded ideologies and practices within heterosexual relationships serve to keep highly educated, apparently empowered and liberated women ‘in their place’, ensuring that they do not fulfil their potential. Traditionally women were socialised into assuming their positions in the home as caregivers and unpaid household labourers. The hope of feminism was that education, economic empowerment and an ideology of ‘can do’ independence would liberate women. However, for many women, it is in the most intimate aspects of their lives—in their sexual relationships with men—that this hope continues to be thwarted.
The Part-time Degree Course and its Influence on Nigerian Women's Participation in Higher Education
Authors: Aderinto, J.A. , Akande J.O. , Aderinto C.O.
Published: April 2006

This article examines the role of the part-time degree course in higher education as it affects women's empowerment and motivation for participation in educational pro-grammes. It examines motives behind Nigerian women's educational participation in part-time degree courses in two of Nigeria's south-western universities. A sample of 200 women randomly drawn from all women enrolled in part-time degree courses in higher education was used for the study. The results from the data established that part-time degree programmes in higher education offered Nigerian women the opportunity to bridge the gender gap and achieve their potentials.
Validity of the Strong Interest Inventory and Skills Confidence Inventory With Mexican American High School Students
Authors: Flores Lisa Y. , Spanierman Lisa B. , Armstrong Patrick Ian , Velez Alexandra D.
Published: April 2006

The structural and concurrent validity of the Strong Interest Inventory (SII) and Skills Confidence Inventory (SCI) was explored with a sample of 487 Mexican American high school students, and findings were compared with normative samples of the SII and SCI. Holland’s (1997) structure was evaluated using circular unidimensional scaling. The hypothesized RIASEC order was supported for general occupational theme (GOT) scores of the SII with female students but not for male students or for general confidence theme (GCT) scores of the SCI with both genders. The model fit for both measures was poor compared with results obtained with reference samples. Additional results supported the concurrent validity of GOT to GCT and both GOT and GCT scores to Holland codes for expressed occupational aspirations. Gender differences were found on four of the six GOTs and three of the six GCTs. Implications for career-related interest and self-efficacy assessment with Mexican American high school students are discussed.
Testing a Model of Nontraditional Career Choice Goals With Mexican American Adolescent Men
Authors: Flores Lisa Y. , Navarro Rachel L. , Smith Jamie L. , Ploszaj Ann M.
Published: April 2006

This study examined the nontraditional career choice goals of 302 Mexican American adolescent men using an extended version of Lent, Brown, and Hackett’s (1994) career choice model. It was hypothesized that several background contextual variables (e.g., acculturation level, parental support, perceived occupational gender barriers) would predict nontraditional career self-efficacy. Nontraditional career self-efficacy was hypothesized to predict nontraditional career interests, and both nontraditional career self-efficacy and nontraditional career interests would predict nontraditional career choice goals. Results supported a modified path model. Mexican American adolescent men’s nontraditional career self-efficacy was predicted by acculturation level and parental support. Additionally, nontraditional career self-efficacy predicted nontraditional career interests, and expressed choice of nontraditional careers was predicted by nontraditional career interests and father’s career nontraditionality. Implications to career counseling with Mexican American adolescent men are discussed.
Clinical significance of ZAP-70 protein expression in B-cell chronic lymphocytic leukemia
Authors: Del Principe Maria Ilaria , Del Poeta Giovanni , Buccisano Francesco , Maurillo Luca , Venditti Adriano , Zucchetto Antonella , Marini Rita , Niscola Pasquale , Consalvo Maria Antonietta Irno , Mazzone Carla , Ottaviani Licia , Panetta Paola , Bruno Antonio , Bomben Riccardo , Suppo Giovanna , Degan Massimo , Gattei Valter , de Fabritiis Paolo , Cantonetti Maria , Lo Coco Francesco , Del Principe Domenico , Amadori Sergio
Published: April 2006

The clinical course of B-cell chronic lymphocytic leukemia (B-CLL) is variable, and novel biologic parameters need to be added to the clinical staging systems to predict an indolent or aggressive outcome. We investigated the 70-kDa zeta-associated protein (ZAP-70), CD38, soluble CD23 (sCD23), and cytogenetics in 289 patients with B-CLL. Both a shorter progression-free survival (PFS) and overall survival (OS) were observed in ZAP-70+ (P < .001), in CD38+ (P < .001) and in sCD23+ patients (P < .001 and P = .013, respectively). ZAP-70+CD38+ or ZAP-70+ patients with an unmutated IgVH status showed both a shorter PFS (P < .001) and OS (P < .001 and P < .001, respectively) as compared with ZAP-70–/CD38– or ZAP-70– patients with mutated IgVH genes. Discordant patients showed an intermediate outcome. Note, ZAP-70+ patients even if CD38– or mutated showed a shorter PFS, whereas ZAP-70– patients even if CD38+ or unmutated had a longer PFS. Furthermore, ZAP-70 positivity was associated with a shorter PFS both within normal karyotype (P < .001) and within the poor-risk cytogenetic subset (P = .02). The predictive value of ZAP-70 expression was confirmed in multivariate analysis. Thus, ZAP-70 protein determined by flow cytometry improves the prognostic significance of cytogenetics and appears to be a better predictor of outcomes than IgVH gene mutational status. On this line, we recommend and are also interested in conducting a prospective randomized trial of early intervention versus observation for ZAP-70+ patients.
The Wingless homolog WNT5A and its receptor Frizzled-5 regulate inflammatory responses of human mononuclear cells induced by microbial stimulation
Authors: Blumenthal Antje , Ehlers Stefan , Lauber Jörg , Buer Jan , Lange Christoph , Goldmann Torsten , Heine Holger , Brandt Ernst , Reiling Norbert
Published: April 2006

Microarray - assisted gene - expression screens of human macrophages revealed WNT5A, a homolog of Wingless, a key regulator of Drosophila melanogaster embryonic segmentation and patterning, to be consistently up-regulated following stimulation with different mycobacterial species and conserved bacterial structures. The expression of WNT5A required Toll-like receptor signaling and NF-κB activation, which identifies a novel induction pathway for a Wingless homolog. We show that human peripheral-blood mononuclear cells express the WNT5A receptor Frizzled-5 (FZD5). Both WNT5A and FZD5 also were detected in granulomatous lesions in the lungs of Mycobacterium tuberculosis–infected patients. Functional studies showed that WNT5A and FZD5 regulate the microbially induced interleukin-12 response of antigen-presenting cells and interferon-γ production by mycobacterial antigenstimulated T cells. Our findings implicate the evolutionarily conserved WNT/Frizzled signaling system in bridging innate and adaptive immunity to infections.
Src Homology 2 (SH2)-Containing 5′-Inositol Phosphatase Localizes to Podosomes, and the SH2 Domain Is Implicated in the Attenuation of Bone Resorption in Osteoclasts
Authors: Yogo Keiichiro , Mizutamari Megumi , Mishima Kazuta , Takenouchi Hiromi , Ishida-Kitagawa Norihiro , Sasaki Takehiko , Takeya Tatsuo
Published: April 2006

c-Src plays an important role in bone resorption by osteoclasts. Here, we show using wild-type and ship−/− osteoclasts that Src homology 2 (SH2)-containing 5′-inositol phosphatase (SHIP) appeared to negatively regulate bone resorption activated by c-Src. SHIP was found to localize to podosomes under the influence of c-Src, and the presence of either the amino-terminal region comprising the SH2 domain or the carboxyl-terminal region was sufficient for its localization. Although SHIP lacking a functional SH2 domain was still found in podosomes, it could not rescue the hyper-bone resorbing activity and hypersensitivity to receptor activator of nuclear factor-κB ligand in ship−/− osteoclasts, suggesting that the localization of SHIP to podosomes per se was not sufficient and the SH2 domain was indispensable for its function. Cas and c-Cbl, known to function in podosomes of osteoclasts, were identified as novel proteins binding to the SHIP SH2 domain by mass spectrometric analysis, and this interaction appeared to be dependent on the Src kinase activity. These results demonstrate that c-Src enhances the translocation of SHIP to podosomes and regulates its function there through the SH2 domain, leading to an attenuation of bone resorption.
Effect of Acute Aldosterone Administration on Gene Expression Profile in the Heart
Authors: Turchin Alexander , Guo Christine Z. , Adler Gail K. , Ricchiuti Vincent , Kohane Isaac S. , Williams Gordon H.
Published: April 2006

Aldosterone is known to have a number of direct adverse effects on the heart, including fibrosis and myocardial inflammation. However, genetic mechanisms of aldosterone action on the heart remain unclear. This paper describes an investigation of temporal changes in gene expression profile of the whole heart induced by acute administration of a physiologic dose of aldosterone in the mouse. mRNA levels of 34,000 known mouse genes were measured at eight time points after aldosterone administration using oligonucleotide microarrays and compared with those of the control animals who underwent a sham injection. A novel software tool (CAGED) designed for analysis of temporal microarray experiments using a Bayesian approach was used to identify genes differentially expressed between the aldosterone-injected and control group. CAGED analysis identified 12 genes as having significant differences in their temporal profiles between aldosterone-injected and control groups. All of these genes exhibited a decrease in expression level 1–3 h after aldosterone injection followed by a brief rebound and a return to baseline. These findings were validated by quantitative RT-PCR. The differentially expressed genes included phosphatases, regulators of steroid biosynthesis, inactivators of reactive oxygen species, and structural proteins. Several of these genes are known to functionally mediate biochemical phenomena previously observed to be triggered by aldosterone administration, such as phosphorylation of ERK1/2. These results provide the first description of cardiac genetic response to aldosterone and identify several potential mediators of known biochemical sequelae of aldosterone administration in the heart.
Insulin-Like Peptide 5: Expression in the Mouse Brain and Mobilization of Calcium
Authors: Dun Siok L. , Brailoiu Eugen , Wang Yulin , Brailoiu G. Cristina , Liu-Chen Lee-Yuan , Yang Jun , Chang Jaw Kang , Dun Nae J.
Published: April 2006

Insulin-like peptide 5 (INSL5) mRNA was detected in the mouse hypothalamus by RT-PCR. Immunohistochemical studies using an antiserum against the mouse INSL5 peptide revealed INSL5-immunoreactive (irINSL5) neurons in the paraventricular, supraoptic, accessory secretory, and supraoptic retrochiasmatic nuclei and immunoreactive cell processes in the internal layer of the median eminence. In the pituitary, irINSL5 was detected in terminal-like elements of the posterior lobe and in cells of the anterior lobe. Double-labeling experiments showed that irINSL5 is expressed in vasopressin-, but not oxytocin-containing neurons. INSL5 (100 nm) administered to dissociated and cultured mouse hypothalamic neurons elevated cytosolic calcium concentrations [Ca2+]i, as assessed by the microfluorimetric fura-2 method. In a Ca2+-free medium, INSL5 induced in dissociated neurons an increase of [Ca2+]i, which was sensitive to the endoplasmic reticulum calcium pump inhibitor thapsigargin (1 μm) and the IP3 receptor blocker 2-aminoethoxydiphenyl borate (100 μm) or xestospongin C (5 μm). Our result provides the first evidence that INSL5 is expressed in a population of cells in the mouse hypothalamus and pituitary and that it elevates [Ca2+]i by a mechanism involving both Ca2+ influx and Ca2+ release from intracellular stores. The concentration of irINSL5 in the hypothalamic-pituitary axis suggests a neuroendocrine function of this insulin superfamily member.
Ghrelin Amplifies Dopamine Signaling by Cross Talk Involving Formation of Growth Hormone Secretagogue Receptor/Dopamine Receptor Subtype 1 Heterodimers
Authors: Jiang Hong , Betancourt Lorena , Smith Roy G.
Published: April 2006

Our objective is to determine the neuromodulatory role of ghrelin in the brain. To identify neurons that express the ghrelin receptor [GH secretagogue receptor (GHS-R)], we generated GHS-R-IRES-tauGFP mice by gene targeting. Neurons expressing the GHS-R exhibit green fluorescence and are clearly evident in the hypothalamus, hippocampus, cortex, and midbrain. Using immunohistochemistry in combination with green fluorescent protein fluorescence, we identified neurons that coexpress the dopamine receptor subtype 1 (D1R) and GHS-R. The potential physiological relevance of coexpression of these two receptors and the direct effect of ghrelin on dopamine signaling was investigated in vitro. Activation of GHS-R by ghrelin amplifies dopamine/D1R-induced cAMP accumulation. Intriguingly, amplification involves a switch in G protein coupling of the GHS-R from Gα11/q to Gαi/o by a mechanism consistent with agonist-dependent formation of GHS-R/D1R heterodimers. Most importantly, these results indicate that ghrelin has the potential to amplify dopamine signaling selectively in neurons that coexpress D1R and GHS-R.
Thyroid-Specific Enhancer-Binding Protein/NKX2.1 Is Required for the Maintenance of Ordered Architecture and Function of the Differentiated Thyroid
Authors: Kusakabe Takashi , Kawaguchi Akio , Hoshi Nobuo , Kawaguchi Rumi , Hoshi Sayuri , Kimura Shioko
Published: April 2006

Thyroid-specific enhancer-binding protein (T/ebp)/Nkx2.1-null mouse thyroids degenerate by embryonic day (E) 12–13 through apoptosis whereas T/ebp/Nkx2.1-heterogyzgous mice exhibit hypothyroidism with elevated TSH levels. To understand the role of T/ebp/Nkx2.1 in the adult thyroid, a thyroid follicular cell-specific conditional knockout (KO) mouse line, T/ebp(fl/fl);TPO-Cre, was established that expresses Cre recombinase under the human thyroid peroxidase (TPO) gene promoter. These mice appeared to be healthy and exhibited loss of T/ebp/Nkx2.1 expression in many, but not all, thyroid follicular cells as determined by immunohistochemistry and real-time PCR, thus presenting a T/ebp-thyroid-conditional hypomorphic mice. Detailed analysis of the thyroids from T/ebp(fl/fl), T/ebp(fl/fl);TPO-Cre, and T/ebp(fl/ko) mice, where the latter mouse line is derived from crosses with the original T/ebp/Nkx2.1-heterozygous mice, revealed that T/ebp(fl/fl);TPO-Cre mice can be classified into two groups with different phenotypes: one having atrophic/degenerative thyroid follicles with frequent presence of adenomas and extremely high serum TSH levels, and the other having an altered thyroid structure with reduced numbers of extraordinary dilated follicles consisting of excessive numbers of follicular cells as compared with those usually found in the normal thyroid. The latter phenotype was also observed in aged T/ebp(fl/ko) mouse thyroids. In vitro three-dimensional thyroid primary cultures using thyroids from T/ebp(fl/fl);TPO-Cre, T/ebp(fl/ko), and T/ebp(fl/fl) mice, and the latter treated with recombinant adenovirus with and without Cre expression, demonstrated that only cells from T/ebp(fl/fl) mice without adeno-Cre treatment formed follicular structures. Taken together, these results suggest that T/ebp/Nkx2.1 is required for maintenance of the normal architecture and function of differentiated thyroids.
Single-Chain, Triple-Domain Gonadotropin Analogs with Disulfide Bond Mutations in the α-Subunit Elicit Dual Follitropin and Lutropin Activities in Vivo
Authors: Jablonka-Shariff Albina , Kumar T. Rajendra , Eklund Joshua , Comstock Anna , Boime Irving
Published: April 2006

The human glycoprotein hormones chorionic gonadotropin (CG), TSH, LH, and FSH are heterodimers composed of a common α-subunit and a hormone-specific β-subunit. The subunits assemble noncovalently early in the secretory pathway. LH and FSH are synthesized in the same cell (pituitary gonadotrophs), and several of the α-subunit sequences required for association with either β-subunit are different. Nevertheless, no ternary complexes are observed for LH and FSH in vivo, i.e. both β-subunits assembled with a single α-subunit. To address whether the α-subunit can interact with more than one β-subunit simultaneously, we genetically linked the FSHβ- and CGβ-subunit genes to the common α-subunit, resulting in a single-chain protein that exhibited both activities in vitro. These studies also indicated that the bifunctional triple-domain variant (FSHβ-CGβ-α), is secreted as two distinct bioactive populations each corresponding to a single activity, and each bearing the heterodimer-like contacts. Although the data are consistent with the known secretion events of gonadotropins from the pituitary, we could not exclude the possibility whether transient intermediates are generated in vivo in which the α-subunit shuttles between the two β-subunits during early stages of accumulation in the endoplasmic reticulum. Therefore, constructs were engineered that would direct the synthesis of single-chain proteins completely devoid of heterodimer-like interactions but elicit both LH and FSH actions. These triple-domain, single-chain chimeras contain the FSHβ- and CGβ-subunits and an α-subunit with cystine bond mutations (cys10–60 or cys32–84), which are known to prevent heterodimer formation. Here we show that, despite disrupting the intersubunit interactions between the α- and both CGβ- and FSHβ-subunits, these mutated analogs exhibit both activities in vivo comparable to nonmutated triple-domain single chain. Such responses occurred despite the absence of quaternary contacts due to the disrupted bonds in the α-subunit. Thus, gonadotropin heterodimer assembly is critical for intracellular events, e.g. hormone-specific posttranslational modifications, but when heterodimers are present in the circulation, the α/β-contacts are not a prerequisite for receptor recognition.
Colonial Conspiracies
Authors: Silverblatt Irene
Published: April 2006

Using records from the Lima office of the Spanish Inquisition, this article explores the cultural politics of Spanish colonialism in the Andes. Spain's imperial enterprise was rooted in the construction of new social beings at the core of modernity: (1) the racialized triad—Indian, Spaniard, and black; and (2) bureaucratized beings created in tandem with institutions of state. Conspiracies and confusions were the result as inquisitors, officers in the most modern bureaucracy of the time, intertwined stereotypes of Jews, Indians, African slaves, and women as part of an etiology of blame. Seventeenth-century Peru provides a glaring example of how fears could coalesce, develop, and ultimately balloon into absurd conspiracy theories, made all the more dangerous by an ideology of reason and the support of an institution of state.
From People to Place and Back Again: Back Translation as Decentering—an Andean Case Study
Authors: Ramírez Susan Elizabeth
Published: April 2006

This article develops a methodology for revealing to an outsider the un-elaborated cultural connotations of translated native words, using a case study of early intercultural communication in an Andean colonial setting. It focuses not on the general translation process from a native language into a European one, but rather on the reverse. “Back translation” of language dealing with native paramount lords opens to cultural outsiders the spiritual dimension of native rulership.
Exploring the Chemistry and Biology of Antitumor Enediyne Chromoprotein C-1027
Authors: Inoue Masayuki
Published: April 2006

C-1027 is an extremely potent antitumor agent, and belongs to a family of chromoprotein antitumor antibiotics, which contain a carrier apoprotein and highly unstable enediyne chromophore. The enediyne spontaneously aromatizes to generate p-benzyne biradical, and subsequently abstracts hydrogens from the DNA sugar backbone, resulting in the sequence-selective double-strand cleavage. On the other hand, the C-1027 apoprotein functions as a carrier, and is likely to escort the reactive chromophore through the cells until reaching the target DNA. The excitement surrounding this molecule lies in the complex molecular architecture of the chromophore, the important biological activity, and the fascinating mode of action. In this account, our studies in the chemistry and biology of C-1027 are presented in three parts: (1) synthetic study of the C-1027 chromophore, (2) spin-trapping study of the C-1027-induced DNA cleavage, and (3) rational design of a kinetically stabilized analog of C-1027.
BDT-TTP-Based π Conductors Containing Divalent Magnetic and Non-Magnetic Inorganic Anions, [MIICl4]2− (M = Co, Mn, Zn)
Authors: Kusamoto Tetsuro , Fujiwara Emiko , Kobayashi Akiko , Cui Hengbo , Otsuka Takeo , Okano Yoshinori , Fujiwara Hideki , Kobayashi Hayao
Published: April 2006

Three BDT-TTP [2,5-bis(1,3-dithiol-2-ylidene)-1,3,4,6-tetrathiapentalene] salts, (BDT-TTP)3[MIICl4](EtOH)x (M = Co, Mn, and Zn; x ≈ 1.0) were prepared. These salts are almost isostructural to one another. The crystals are composed of BDT-TTP columns, “BDT-TTP tapes” that occupy the interstitial positions between BDT-TTP columns, [MIICl4]2− anions and the crystal solvents, respectively. These salts showed weakly metallic conducting behavior down to about 150 K. At low temperature, the resistivities increased gradually with decreasing temperature, but the systems retained fairly high conductivities even at around 30 K. The [ZnIICl4]2− salt indicated temperature independent paramagnetism down to low temperature. While the susceptibilities of the [CoIICl4]2− and [MnIICl4]2− salts showed the coexistence of π conduction electrons and localized high-spins of the magnetic CoII and MnII atoms, no significant π–d interaction was observed. Band structure calculations were performed with taking account of the possibility of inhomogeneous distribution of π electrons over the crystallographically independent three BDT-TTP molecules. The system has wide and narrow one-dimensional bands that originate from BDT-TTP columns and tapes, respectively. However, due to the interaction between BDT-TTP columns and tapes, the system gave a unique two-dimensional electronic band. The calculated energy dispersion curves were consistent with the weakly metallic behavior of the systems.
Anodic Cyanation of 1-Arylpyrrolidines
Authors: Liu Wei , Ma Yuan , Yin Yingwu , Zhao Yufen
Published: April 2006

The electrochemical cyanation of 1-arylpyrrolidines was carried out in methanol containing sodium cyanide at a platinum anode in a divided cell. The reaction gave the corresponding α-aminonitriles 2, together with the unexpected 1-arylpyrrolidine-2-carboximidic acid methyl esters 3 as byproducts.
Calcium-Binding Membrane Influence on Polymorph and Morphology of Calcium Carbonate Formed by Biomimetic Mineralization
Authors: Ichikawa Kazuhiko , Shimomura Noriyuki
Published: April 2006

The typical conclusions can be drawn as follows: (1) Since vaterite was only formed on calcium-binding poly(l-aspartate)-coated surface between 15 and 35 °C, the carbonic anhydrase (CA)-arising activity of zinc array (i.e., zinc-coordinated imidazolin-terminated silane monolayer, as shown in Chem. Eur. J.2003, 9, 3235) prevailed the temperature influence on the polymorph of calcium carbonate. Time evolution of calcium carbonate formation was enhanced by the zinc array. (2) The calcium carbonate crystallized only on imidazolin- and sulfonate-terminated silane membranes has shown a number of microspheres of 1 μm more or less in diameter. (3) The higher temperature and higher pH induced aragonite formation at the sulfonate-terminated Nafion membrane in the presence of the above zinc array. (4) The observed morphology of aragonite or vaterite was similar to the spherulitic aragonite or vaterite formed by biological mineralization in marine organisms.
Partitionings of Major-to-Ultratrace Elements in Bittern as Determined by ICP-AES and ICP-MS with Aid of Chelating Resin Preconcentration
Authors: Ji Shan , Zhu Yanbei , Yabutani Tomoki , Itoh Akihide , Haraguchi Hiroki
Published: April 2006

The concentrations of major-to-ultratrace elements in bittern, which was obtained after seawater concentration in the salt preparation process, were investigated by ICP-AES (inductively coupled plasma atomic emission spectrometry) and ICP-MS (inductively coupled plasma mass spectrometry) with and without the aid of chelating resin preconcentration. As a result, 34 elements in bittern could be determined in the concentration range from 107 to 10−3 ng mL−1 with good RSDs (less than 5%) for most analyte elements. Based on the experimental results, the concentrations of the elements in bittern were compared with those in seawater. Furthermore, the distribution factors of major-to-ultratrace elements in bittern were estimated to elucidate the partitionings of those elements among the calcium precipitate, the salt and the bittern from coastal seawater. The results suggest that the concentrations of the elements in bittern significantly depended on their chemical forms in seawater. For example, K and Mg in ionic form, V, Mo, W, and U in oxoanion form, and Cu and Zn in complex form with organic molecules in seawater, were much more partitioned in bittern than in salt.
Synthesis and Steady-State Spectroscopic Study of 5-Aryl-2,2′-bipyridyls. New Fluorescent Compounds in Solid State
Authors: Mizuyama Naoko , Tominaga Yoshinori , Kohra Shinya , Ueda Kazuo , Hirayama Shun-ichi , Shigemitsu Yasuhiro
Published: April 2006

The absorption and fluorescent properties of newly synthesized 5-aryl-2,2′-bipyridyls were examined both in solution and in the solid state. The 6-methoxy derivatives 5a–5c have weak fluorescence, whereas 6-amino derivatives 7a–7f showed strong fluorescence. Their spectroscopic properties were computationally analyzed using semi-empirical molecular orbital calculations. The geometries of the ground (S0) and the first singlet excitation states (S1) were optimized and employed to estimate the vertical transition energies. The drastic differences in fluorescent intensities between 5a–5c and 7a–7f can be qualitatively explained by the relative energy levels S1 and the neighboring triplet level; the energy gaps supposedly regulate the non-radiative intersystem crossing (ISC) probabilities. On the relaxed S1 geometry, 5a–5c have quite small S1–triplet energy gaps, whereas 7a–7f have no such quasi-degeneracies, leading to their quantitatively different quantum yields.
Synthesis and Characterization of Potential Efficient Electroluminescent Materials: 2-Phenyl-5-[4-(4-phenylamino-2H-1,2,3-triazol-2-yl)]phenyl-1,3,4-oxadiazole Derivatives
Authors: Zhou Jia-Xing , Wong Fung Fuh , Chen Chun-Yen , Yeh Mou-Yung
Published: April 2006

Recently, 1,3,4-oxadiazole-based on heterocyclic compounds were investigated as electroluminescent materials. In this work, we first introduce 1,2,3-triazole to synthesize a series of 1,3,4-oxadiazole–1,2,3-triazole hybrids derivatives as potential electroluminescent materials and explore the effect of modification of the 1,2,3-triazole moiety. The λmax values of the UV–vis of 1,3,4-oxadiazole–1,2,3-triazole hybrids are promoted to longer wavelengths (340–350 nm) than the traditional 1,2,3-triazole derivatives (280–330 nm) in solutions and have a bathochromic shift to 350–360 nm in THF solution. The λmax values of the photoluminescence (PL) spectra are in the range 406–480 nm in solutions. Compound 7h evaporated to form films on quartz substrates, had a maximum at 455 nm and showed a red-shift (≈40 nm) with respect to the solution spectrum. The solution fluorescence quantum yields (Φf) were measured, all of which fell into the range 0.65–0.76, and were determined relative to that of 2-phenyl-5-(4-biphenyl)-1,3,4-oxadiazole in benzene (Φf = 0.80). 1,3,4-Oxadiazole–1,2,3-triazole hybrids derivatives show unclearly reversible reduction processes in cyclic voltammogram measurements. Following spectroscopic studies and observation of the electrochemical behaviors, 1,3,4-oxadiazole–1,2,3-triazole derivatives were determined to be highly potential efficient blue electroluminescent materials.
Structural and Catalytic Properties of Silica-Coated Alumina
Authors: Sato Satoshi , Takahashi Ryoji , Sodesawa Toshiaki , Shin Daiji , Ichikawa Naoki , Ogura Katsuyuki
Published: April 2006

SiO2-coated Al2O3 powders were prepared by depositing hydrolyzed tetraethoxysilane (TEOS) on Al(OH)3 and γ-Al2O3 at 40 °C. In the preparation using Al(OH)3 with a specific surface area (SA) of ca. 40 m2 g−1 as a support, loading of silica deposited on the Al(OH)3 was saturated at 80 mg galumina−1. Ammonium nitrate, a catalyst for the hydrolysis of TEOS, increased silica loading linearly with increasing the amount of TEOS charged, while the silica aggregated on the Al(OH)3. At temperatures of >300 °C, the core Al(OH)3 coated with aggregated silica was fragmented into a mixture of small particles of pure alumina and silica–alumina diminishing small particles with a large SA of >400 m2 g−1. The small surface area of the support Al(OH)3 is ineffective in generating active acid sites. In the deposition of silica on γ-Al2O3 with a SA of 450 m2 g−1, however, silica loading increased with increasing the amount of TEOS charged at 40 °C without using ammonium nitrate. Silicate species with thinner layer structures uniformly covered the γ-Al2O3 surface. The SiO2-covered γ-Al2O3 showed higher catalytic activity than the SiO2–Al2O3 prepared from Al(OH)3 did.
Complex Impedance and Solid-State NMR Studies on a Novel High Proton Conductor Na-RUB-18
Authors: Ishimaru Shin’ichi , Togawa Maki , Ikeda Ryuichi , Shimizu Tadashi , Shinohara Emi , Umemura Yasushi
Published: April 2006

Measurements of complex impedance and 2H NMR spectra were performed on a layer silicate compound, Na-RUB-18 (sodium octosilicate, NaSi4O8(OH)·nH2O), to investigate hydrogen dynamics in crystals. A high proton conductivity amounting to ca. 10−1 S m−1 was observed at room temperature under 100% relative humidity. Activation energies of the proton conduction were estimated to be 125 and 18 kJ mol−1 below and above 290 K, respectively. 2H NMR spectra observed on a deuterated analog revealed 1-D proton conduction through hydrogen-bond networks formed among silanol groups on the layer surface and water molecules in the interlayer space. This material was discovered to be a new type of solid proton-conductor contributed by very weak acids in contrast to the strong-acid type ones so far reported.
Nucleobase catalysis in the hairpin ribozyme
Authors: Wilson Timothy J. , Ouellet Jonathan , Zhao Zheng-Yun , Harusawa Shinya , Araki Lisa , Kurihara Takushi , Lilley David M.J.
Published: April 2006

RNA catalysis is important in the processing and translation of RNA molecules, yet the mechanisms of catalysis are still unclear in most cases. We have studied the role of nucleobase catalysis in the hairpin ribozyme, where the scissile phosphate is juxtaposed between guanine and adenine bases. We show that a modified ribozyme in which guanine 8 has been substituted by an imidazole base is active in both cleavage and ligation, with ligation rates 10-fold faster than cleavage. The rates of both reactions exhibit bell-shaped dependence on pH, with pKa values of 5.7 ± 0.1 and 7.7 ± 0.1 for cleavage and 6.1 ± 0.3 and 6.9 ± 0.3 for ligation. The data provide good evidence for general acid–base catalysis by the nucleobases.
Functions of hUpf3a and hUpf3b in nonsense-mediated mRNA decay and translation
Authors: Kunz Joachim B. , Neu-Yilik Gabriele , Hentze Matthias W. , Kulozik Andreas E. , Gehring Niels H.
Published: April 2006

The exon–junction complex (EJC) components hUpf3a and hUpf3b serve a dual function: They promote nonsense-mediated mRNA decay (NMD), and they also regulate translation efficiency. Whether these two functions are interdependent or independent of each other is unknown. We characterized the function of the hUpf3 proteins in a λN/boxB-based tethering system. Despite the high degree of sequence similarity between hUpf3b and hUpf3a, hUpf3a is much less active than hUpf3b to induce NMD and to stimulate translation. We show that induction of NMD by hUpf3 proteins requires interaction with Y14, Magoh, BTZ, and eIF4AIII. The protein region that mediates this interaction and discriminates between hUpf3a and hUpf3b in NMD function is located in the C-terminal domain and fully contained within a small sequence that is highly conserved in Upf3b but not Upf3a proteins. Stimulation of translation is independent of this interaction and is determined by other regions of the hUpf3 protein, indicating the presence of different downstream pathways of hUpf3 proteins either in NMD or in translation.
The coiled-coil domain of the Nop56/58 core protein is dispensable for sRNP assembly but is critical for archaeal box C/D sRNP-guided nucleotide methylation
Authors: Zhang Xinxin , Champion Erica A. , Tran Elizabeth J. , Brown Bernard A. , Baserga Susan J. , Maxwell E. Stuart
Published: April 2006

Archaeal box C/D sRNAs guide the methylation of specific nucleotides in archaeal ribosomal and tRNAs. Three Methanocaldococcus jannaschii sRNP core proteins (ribosomal protein L7, Nop56/58, and fibrillarin) bind the box C/D sRNAs to assemble the sRNP complex, and these core proteins are essential for nucleotide methylation. A distinguishing feature of the Nop56/58 core protein is the coiled-coil domain, established by α-helices 4 and 5, that facilitates Nop56/58 self-dimerization in vitro. The function of this coiled-coil domain has been assessed for box C/D sRNP assembly, sRNP structure, and sRNP-guided nucleotide methylation by mutating or deleting this protein domain. Protein pull-down experiments demonstrated that Nop56/58 self-dimerization and Nop56/58 dimerization with the core protein fibrillarin are mutually exclusive protein:protein interactions. Disruption of Nop56/58 homodimerization by alteration of specific amino acids or deletion of the entire coiled-coil domain had no obvious effect upon core protein binding and sRNP assembly. Site-directed mutation of the Nop56/58 homodimerization domain also had no apparent effect upon either box C/D RNP- or C′/D′ RNP-guided nucleotide modification. However, deletion of this domain disrupted guided methylation from both RNP complexes. Nuclease probing of the sRNP assembled with Nop56/58 proteins mutated in the coiled-coil domain indicated that while functional complexes were assembled, box C/D and C′/D′ RNPs were altered in structure. Collectively, these experiments revealed that the self-dimerization of the Nop56/58 coiled-coil domain is not required for assembly of a functional sRNP, but the coiled-coil domain is important for the establishment of wild-type box C/D and C′/D′ RNP structure essential for nucleotide methylation.
Real-Time Nucleic Acid Sequence–Based Amplification Assay to Quantify Changes in Mitochondrial DNA Concentrations in Cell Cultures and Blood Cells from HIV-Infected Patients Receiving Antiviral Therapy
Authors: Timmermans Eveline C , Tebas Pablo , Ruiter Jos PN , Wanders Ronald JA , de Ronde Anthony , de Baar Michel P
Published: April 2006

Background: To study the clinical relevance of changes in mitochondrial DNA (mtDNA) in peripheral blood mononuclear cells (PBMCs) attributable to HIV infection and/or combination antiretroviral therapy (cART), a high-throughput molecular assay to quantify mtDNA is required.

Methods: We developed a quantitative real-time duplex nucleic acid sequence–based amplification assay in which both mtDNA and nuclear DNA are simultaneously amplified in 1 tube. The assay could accurately quantify mtDNA in a range of 15–1500 copies of mtDNA per 2 genomic copies with an intrarun variation of 11% and an interrun variation of 16%. We compared this real-time assay with the lactate/pyruvate ratios in fibroblasts incubated with glucose and exposed to zalcitabine. Additionally, we studied the effects of platelet contamination and the in vivo effects of cART on mtDNA in PBMCs from a small group of patients.

Results: Decreases in mtDNA preceded the increase in lactate/pyruvate ratios and vice versa when zalcitabine was eliminated from the culture. Platelets affected the mtDNA in PBMCs if >5 platelets per PBMC were present. Within 12 weeks, mtDNA increased and remained increased in PBMCs from patients on continuous treatment with zidovudine/lamivudine/indinavir therapy (P = 0.03), but increased if patients were switched to stavudine/didanosine therapy (P = 0.008).

Conclusion: After drug exposure, the mtDNA assay can detect changes in mtDNA concentrations in cell lines and PBMCs, when properly controlled for platelet effects, earlier than traditional assays.
Bagging and Boosting Classification Trees to Predict Churn
Authors: Lemmens Aurélie , Croux Christophe
Published: April 2006

In this article, the authors explore the bagging and boosting classification techniques. They apply the two techniques to a customer database of an anonymous U.S. wireless telecommunications company, and both significantly improve accuracy in predicting churn. This higher predictive performance could ultimately lead to incremental profits for companies that use these methods. Furthermore, the results recommend the use of a balanced sampling scheme when predicting a rare event from large data sets, but this requires an appropriate bias correction.
Hepatorenal syndrome
Authors: Demırtaş Selda , Can Murat , Yarpuzlu Ayşegül
Published: April 2006

This article summarizes the literature on current definition, suggested pathogenetic mechanisms and the role of laboratory assessment in the differential diagnosis of hepatorenal syndrome (HRS) from other causes of renal disease that may arise during hepatic cirrhosis and some diseases affecting both liver and kidney. It should be remembered that the main theory suggested for the pathogenesis of HRS is the arterial vasodilation hypothesis of portal hypertension, ending in type 1 and type 2 HRS, but there is no consensus supporting either mechanism as a solid theory for initiation of HRS pathogenesis to date. No laboratory test can firmly establish a diagnosis of HRS, which is mainly based on the absence of any specific cause of renal failure. Laboratory and ultrasonographic tests based on non-invasive techniques are being investigated as possible diagnostic approaches.
Clinical relevance of biological variation: the lesson of brain natriuretic peptide (BNP) and NT-proBNP assay
Authors: Clerico Aldo , Carlo Zucchelli Gian , Pilo Alessandro , Passino Claudio , Emdin Michele
Published: April 2006

The clinical relevance of brain natriuretic peptide (BNP) and N-terminal (NT)-proBNP assays as a diagnostic tool and prognostic marker in patients with cardiovascular diseases has recently been confirmed. However, several studies demonstrated variation of intra-individual BNP concentrations of >30% (ranging from 30% to 50%) with reference change values at the 95% confidence interval (i.e., the estimated critical difference) ranging from 99% to 130% in healthy subjects and heart failure patients. According to this estimated confidence interval, only a great variation in plasma BNP levels should be considered significant in an individual patient (for example, a decrease of >50% or an increase of more than two-fold). Many recent clinical studies have demonstrated that BNP variations below this estimated critical difference could also have clinical relevance. Like the concentration of other neuro-hormones, levels of plasma BNP fluctuate widely and rapidly along with heart rhythm and blood pressure variations in response to physiological stimuli. However, biological variation of BNP should not be interpreted strictly as random fluctuation around a homeostatic set point, as assumed by the common model used in all studies on biological variation of BNP reported in the literature. These results cannot be directly transferred to clinical practice. While awaiting more accurate studies, we suggest that variations of plasma BNP three-fold greater than the analytical imprecision should be considered as potentially relevant from a physiological and clinical point of view.
Multicenter evaluation of the interference of hemoglobin, bilirubin and lipids on Synchron LX-20 assays
Authors: Steen Gerard , Vermeer Henricus J. , Naus André J.M. , Goevaerts Berrie , Agricola Pauline T. , Schoenmakers Christian H.H.
Published: April 2006

The influence of interference by hemolysis, icterus and lipemia on the results of routine chemistries may lead to wrong interpretations. The H-, I- and L-indices that can be measured by the Beckman LX-20 instrument (Beckman Coulter) in serum or plasma samples are a reliable semi-quantitative measure of the size of these interferences. A survey carried out in 16 Dutch clinical laboratories on the use of these indices demonstrated that in several of these laboratories, the influence of interferences is largely underestimated. Therefore, a multicenter study was carried out in which we examined the interference of hemolysis, icterus and lipemia on 32 analytes. On the basis of biological variation, we decided on cutoff indices above which analytically significant interference exists. We found analytically significant interference by hemolysis, icterus or lipemia, in 12, 7 and 15 of the 32 analytes studied, respectively. Flagging of results on the basis of analytically significant interference, however, results in too many clinically insignificant comments. On the basis of clinical significance, we conclude that significant interference by hemolysis, icterus or lipemia is present in only 5, 6 and 12 of the analytes studied, respectively. Use of the cutoff indices presented here facilitates optimal use of the LX-20 indices to prevent reporting of wrong results due to interference.