bluuebunny/crossref_metadata_2025 huggingface dataset:
Up-Regulating the Hemeoxygenase System Enhances Insulin Sensitivity and Improves Glucose Metabolism in Insulin-Resistant Diabetes in Goto-Kakizaki Rats
Authors: Ndisang Joseph Fomusi , Jadhav Ashok
Published: February 2009

Insulin-mediated signal transduction is positively correlated to adiponectin, adenosine monophosphate-activated protein kinase (AMPK), and glucose-transporter-4 (GLUT4) but negatively to oxidative/inflammatory mediators such as nuclear factor-κB, activating-protein (AP)-1, AP-2, and c-Jun-N-terminal-kinase. Although hemeoxygenase (HO) suppresses oxidative insults, its effects on insulin-sensitizing agents like AMPK and GLUT4 remains unclear and were investigated using Goto-Kakizaki rats (GK), a nonobese insulin-resistant type-2 diabetic model. HO was induced with hemin or inhibited with chromium mesoporphyrin (CrMP). The application of hemin to GK rats evoked a 3-month antidiabetic effect, whereas the HO-inhibitor, CrMP, exacerbated hyperglycemia and nullified insulin-signaling/glucose metabolism. Interestingly, the antidiabetic was accompanied by a paradoxical increase of insulin alongside the potentiation of insulin-sensitizing agents such as adiponectin, AMPK, and GLUT4 in the gastrocnemius muscle. Furthermore, hemin enhanced mediators/regulators of insulin signaling like cGMP and cAMP and suppressed oxidative insults by up-regulating HO-1, HO activity, superoxide dismutase, catalase, and the total antioxidant capacity in the gastrocnemius muscle. Accordingly, oxidative markers/mediators including nuclear factor-κB, AP-1, AP-2, c-Jun-N-terminal-kinase, and 8-isoprostane were abated, whereas CrMP annulled the cytoprotective and antidiabetic effects of hemin. Correspondingly, ip glucose tolerance, insulin tolerance, and homeostasis model assessment insulin resistance analyses revealed improved glucose tolerance, reduced insulin intolerance, enhanced insulin sensitivity, and reduced insulin resistance in hemin-treated GK rats. In contrast, CrMP, abolished the insulin-sensitizing effects and restored and/or exacerbated insulin resistance. Our study unveils a 3-month enduring antidiabetic effect of hemin and unmasks the synergistic interaction among the HO system, adiponectin, AMPK, and GLUT4 that could be explored to enhance insulin signaling and improve glucose metabolism in insulin-resistant diabetes.
Obese Women Exhibit Differences in Ovarian Metabolites, Hormones, and Gene Expression Compared with Moderate-Weight Women
Authors: Robker Rebecca L. , Akison Lisa K. , Bennett Brenton D. , Thrupp Penny N. , Chura Lindsay R. , Russell Darryl L. , Lane Michelle , Norman Robert J.
Published: February 2009

Context: Obese women experience longer times to conception, even if they are young and cycling regularly, which is suggestive of alterations in ovarian function during the periconceptual period.

Objective: This study sought to determine whether there are alterations in the preovulatory follicular environment that are likely to influence oocyte developmental competence.

Design, Setting, and Participants: Women attending a private infertility clinic were categorized into body mass index (BMI) groups of moderate (n = 33; BMI 20–24.9 kg/m2), overweight (n = 31; BMI 25–29.9 kg/m2), and obese (n =32; BMI ≥30 kg/m2).

Intervention: For each patient, follicular fluid was recovered from single follicles at oocyte retrieval, granulosa cells were pooled from multiple follicular aspirates and cumulus cells were pooled after separation from the oocytes.

Main Outcome Measures: Follicle fluid was assayed for hormones and metabolites. Granulosa and cumulus cells were analyzed for mRNA expression of insulin signaling components (IRS-2 and Glut4), glucose-regulated genes (ChREBP, ACC, and FAS) and insulin-regulated genes (SREBP-1, CD36, and SR-BI) associated with obesity/insulin resistance.

Results: Increasing BMI was associated with increased follicular fluid insulin (P < 0.001), lactate (P = 0.01), triglycerides (P = 0.0003), and C-reactive protein (P < 0.0001) as well as decreased SHBG (P = 0.001). IRS-2, Glut4, ChREBP, and SREBP exhibited cell-type-specific expression but were not affected by BMI. CD36 and SRBI mRNA were modestly altered in granulosa cells of obese compared with moderate-weight women.

Conclusions: Obese women exhibit an altered ovarian follicular environment, particularly increased metabolite, C-reactive protein, and androgen activity levels, which may be associated with poorer reproductive outcomes typically observed in these patients.
Developmental roles of the histone lysine demethylases
Authors: Nottke Amanda , Colaiácovo Mónica P. , Shi Yang
Published: February 2009

Since the discovery of the first histone lysine demethylase in 2004, two protein families with numerous members have been identified that demethylate various histone lysine residues. Initial studies of the histone lysine demethylases focused on their in vitro enzymatic activity but, more recently,model organisms have been used to examine the roles of these enzymes in vivo. Here, we review recent insights into the roles of the histone lysine demethylases in multiple aspects of development across various species,including in germline maintenance and meiosis, in early embryonic development and differentiation, and in hormone receptor-mediated transcriptional regulation.
Foxa2 regulates polarity and epithelialization in the endoderm germ layer of the mouse embryo
Authors: Burtscher Ingo , Lickert Heiko
Published: February 2009

In the mouse, one of the earliest events in the determination of cell fate is the segregation of cells into germ layers during gastrulation; however, the cellular and molecular details are not well defined due to intrauterine development. We were able to visualize a clear sequence of events occurring in the process of germ-layer formation, using immunohistochemistry and time-lapse confocal imaging. The T-box transcription factor brachyury (T) and the Forkhead transcription factor Foxa2 specify mesoderm and endoderm in the posterior epiblast. Fate-specified epiblast cells lose their polarity and undergo epithelial-mesenchymal transition to invade into the primitive streak region, where these cell populations quickly separate and differentiate into morphologically and molecularly distinct Foxa2-positive endoderm and T-positive mesoderm populations. The endoderm cells flatten and acquire apical-basal polarity during intercalation into the outside epithelium in order to establish proper intracellular junctions with pre-existing cells. By contrast, the mesodermal cells become spherical during migration and acquire a mesenchymal fate. Interestingly, axial mesodermal cells are descended from Foxa2-positive epiblast cells that upregulate T protein in the anterior primitive streak region. These cells, as well as Foxa2-positive endoderm cells, are highly polarized and epithelialized, suggesting that Foxa2 promotes an epithelial fate and suppresses a mesenchymal fate. This observation is supported by the fact that Foxa2 mutant endodermal cells fail to maintain polarity and do not establish proper cellular junctions, and are thus unable to functionally integrate into the endoderm epithelium. We propose that Foxa2 regulates a molecular program that induces an epithelial cellular phenotype.
Synthesis of Organic Shell–Inorganic Core Hybrid Nanoparticles by Wet Process and Investigation of Their Advanced Functions
Authors: Yamada Mami
Published: February 2009

This account reviews the chemical synthesis of inorganic nanoparticles stabilized by an organic shell layer and the investigation of their specific characteristics. Consideration of design and construction of organic–inorganic hybrid nanoparticles by wet process is indispensable in order to exploit the unprecedented nature resulting from the fusion of both organic and inorganic traits. In a series of studies, two synthetic parameters were the center of focus: physical construction of the inorganic core and the chemical constituents introduced. External stimuli such as electric fields or solvent polarity can be utilized to transform the characteristics of nanoparticles when redox active or liquid crystalline molecules as an organic shell are attached to the surface of an inorganic nano-core. In another case, the catalytic activities of nanoparticles are controllable by modifying the crystal faces and the surface area of the inorganic cores in connection with shape and size. Novel nanomaterial has also been fabricated by choosing a metal coordination polymer as a core, leading to the first isolation of alkyl chain-stabilized metal coordination nano-polymers (MCNPs). The compounds are listed as Pt nano-cubes, size-selected Au nanoparticles, metal hexacyanoferrate MCNPs, and metal nanoparticles functionalized by biferrocene, anthraquinone, and triphenylene derivatives. Synthetic procedures and remarkable characteristics are demonstrated.
Construction of Supramolecular Systems Based on Endohedral Metallofullerenes
Authors: Tsuchiya Takahiro , Akasaka Takeshi , Nagase Shigeru
Published: February 2009

This account describes the redox behaviors of endohedral metallofullerenes having remarkable electron-accepting and -donating abilities, which accompany the transformation between their paramagnetic and diamagnetic states. A convenient method of isolating endohedral metallofullerene by means of selective reduction from carbon soot extracts is also developed. Successful isolation in large amount by utilizing this method allows examination of the construction of a supramolecular system based on endohedral metallofullerenes with azacrown ethers, unsaturated thiacrown ethers, and organic donor molecules. Consequently, endohedral metallofullerenes are revealed to form an inclusion complex with the crown compounds by electron transfer, and a stimuli-responsive reversible electron transfer system is constructed by using endohedral metallofullerenes and organic donors. These electron transfers proceed readily even in the ground state, which is a specific phenomenon for endohedral metallofullerenes.
Binding and Catalytic Properties of 2-O- and 3-O-Permethylated Cyclodextrins
Authors: Nagata Takuya , Yoshikiyo Keisuke , Matsui Yoshihisa , Yamamoto Tatsuyuki
Published: February 2009

Hexakis(3-O-methyl)-α-cyclodextrin (3α) bound to m- and p-nitrophenolate ions more strongly, whereas hexakis(2-O-methyl)-α-cyclodextrin (2α) bound less strongly than native α-cyclodextrin. ROESY spectra showed that the 3-O-methyl groups of 3α interact with the guest protons, whereas 2-O-methyl groups of 2α do not. 3α accelerated and 2α decelerated the cleavage of m-nitrophenyl acetate in an alkaline solution, suggesting that the C(2)–OH of α-cyclodextrin is more catalytic than the C(3)–OH. However, the catalytic effect of 3α was much smaller than that of native α-cyclodextrin. Loss of hydrogen bonding between the C(3)–OH and C(2)–OH by 3-O-permethylation is responsible for the small catalytic effects of 3α. Similar results were obtained for β-cyclodextrin analogs.
Structural Requirement for Chiral Recognition of Amino Acid by (18-Crown-6)-tetracarboxylic Acid: Binding Analysis in Solution and Solid States
Authors: Nagata Hiroomi , Machida Yoshio , Nishi Hiroyuki , Kamigauchi Miyoko , Minoura Katsuhiko , Ishida Toshimasa
Published: February 2009

(+)-(18-Crown-6)-tetracarboxylic acid (18C6H4) is used as a chiral selector for various amino acids, where the l-isomer is usually eluted prior to the d-isomer in HPLC using 18C6H4-linked column. To clarify the structural scaffold of (+)-18C6H4 responsible for chiral separation of amino acids, we have previously investigated the interaction mode between (+)-18C6H4 and amino acids using X-ray analysis. However, no conclusive results could be obtained to explain the reverse elution order in the case of serine and to establish a general separation rule of chiral amino acid by (+)-18C6H4 in HPLC. Thus, to clarify the exceptional result obtained with serine and to set a general separation rule, interaction between (+)-18C6H4 and α-amino-n-butyric acid, valine, and alanine, as methyl substitutes of the methyl groups for the hydroxy groups of serine and threonine, and the simplest chiral amino acid, respectively, was investigated both in solution and solid states. Consequently, it was found that an asymmetric bowl-like conformation of (+)-18C6H4 is necessary for chiral separation. This conformation is constructed by chiral-specific interaction between the Cα–H groups of the amino acid and the polar oxygen atoms of (+)-18C6H4. It was also found that the exceptional reverse elution observed with serine is due to additional interaction between the polar groups of the amino acid side chain and (+)-18C6H4.
Tropolone-Terminated Oligomeric Fluorophores with Responsive Properties to External Environment
Authors: Takagi Koji , Saiki Kazuhiro , Hayashi Hirokazu , Ohsawa Hiroyasu , Matsuoka Shin-ichi , Suzuki Masato
Published: February 2009

Tropolone-terminated oligomeric fluorophores (Tp2OP, Tp2OPV, and Tp2OPE) were prepared by palladium-catalyzed coupling reactions. A phenylene-type Tp2OP showed an emission maximum in the blue fluorescent region and the fluorescence quantum yield was relatively low. Tp2OPV and Tp2OPE, which included vinylene and ethynylene units as connecting groups, respectively, had emission maxima at longer wavelength regions than Tp2OP. The UV spectra of Tp2OP gradually red shifted as the dielectric constant of solvent increased. Tp2OP exhibited positive solvatofluorochromic behavior, which related to an increase of the dipole moment due to the charge-transfer characteristics of the emitting state. The fluorescence quantum yields (QYs) of fluorophores exponentially fell with increasing MeOH content in THF solution. Upon addition of CuCl2 to Tp2OP until the ratio of [Cu2+]/[Tp2OP] reached 1, the UV spectra exhibited a red-shift. The emission maximum wavelength of Tp2OP blue shifted and a remarkable decrease of the PL intensity was observed. Tp2OP showed metal ion-response, especially in PL spectra.
Exalted Resonance Demands in the Substituent Effects on the Acetolyses of 2-Arylethyl Trifluoromethanesulfonates Destabilized by CN and CF3 Groups
Authors: Usui Satoshi , Tsuboya Shoko , Umezawa Yukihiro , Hazama Ken , Okamura Mutsuo
Published: February 2009

Substituent effects on the acetolysis rates of 2-aryl-1-cyano-1-(trifluoromethyl)ethyl trifluoromethanesulfonates (α-OTf) and 2-aryl-2-cyano-2-(trifluoromethyl)ethyl trifluoromethanesulfonates (β-OTf) were investigated by using LArSR equation. The obtained ρ and r+ values were ρ = −3.28, r+ = 0.98 and ρ = −3.48, r+ = 0.93 for the acetolysis of α-OTf and β-OTf, respectively. The obtained ρ values are comparable to those for typical aryl-assisted solvolyses, but the r+ values are much larger. The large r+ values suggest that the ester bond cleavages in the deactivated aryl-assisted solvolyses are assisted by the strong participation of the β-aryl group.
Chlorophyll- and Bacteriochlorophyll-Derived Colorimetric Chemosensors for Amine Detection
Authors: Sasaki Shin-ichi , Kotegawa Yuki , Tamiaki Hitoshi
Published: February 2009

Chlorophyll and bacteriochlorophyll derivatives possessing a trifluoroacetyl group at the 3-position were synthesized as new colorimetric sensors for amine detection. α-Amino alcohol formation of the free-base chlorin and metallochlorins showed visual color changes from brown to purple and from green to blue, respectively. On the other hand, bacteriochlorin derivative showed large blue-shifts of the Qy peak in the near-infrared region (775 → 724 nm) and the Qx peak in the visible region (549 → 520 nm), which are advantageous points for amine sensing. Clear color change was observed from pink to turquoise by the formation of α-amino alcohol adduct.
The Origin of the Relative Stability of Axial Conformers of Cyclohexane and Cyclohexanone Derivatives: Importance of the CH/n and CH/π Hydrogen Bonds
Authors: Takahashi Osamu , Yamasaki Katsuyoshi , Kohno Yuji , Ueda Kazuyoshi , Suezawa Hiroko , Nishio Motohiro
Published: February 2009

Ab initio MO calculations were carried out at the MP2/6-311++G(d,p) level to investigate the Gibbs energy of conformational isomers of cyclohexanes cyclo-C6H11X 3 and cyclohexanones cyclo-C6H9OX 4. In 3, it has been found that the conformer bearing an oxygen or halogen atom (X = OCH3, F, Cl, and Br) at the axial orientation is relatively stable as compared to corresponding alkyl cyclohexanes; the result is consistent with documented experimental data. For X = CCH and CN, the axial conformer has been suggested to be slightly more stable. In 4, the axial conformer has been found to be more stable than the equatorial conformer, except for X = OH. Short non-bond distances have been disclosed in every axial conformer of 3 and 4, between axial CHs of the cyclohexane ring and X. The reason for the relative stability of the axial conformers has been sought in the context of the CH/n and CH/π hydrogen bonds. We suggest that a considerable part of the relative stability of the axial conformation is attributed to intramolecular CH/n and CH/π hydrogen bonds. Natural bonding orbital charges of the relevant atoms are consistent with the above suggestion.
Photochemical Removal of NO, NO2, and N2O by 146 nm Kr2 Excimer Lamp in N2 at Atmospheric Pressure
Authors: Tsuji Masaharu , Kamo Naohiro , Kawahara Takashi , Kawahara Masashi , Senda Makoto , Hishinuma Nobuyuki
Published: February 2009

The photochemical removal of NO, NO2, and N2O was investigated in N2 using a 146 nm Kr2 (25 mW cm−2) excimer lamp. The results obtained were compared with those obtained using 172 nm Xe2 (50 or 300 mW cm−2) excimer lamps. The removal rates of NO and NO2 at 146 nm were 11 and 36% slower than those at 172 nm, respectively. On the other hand, the removal rate of N2O at 146 nm was 21 times faster than that at 172 nm. The differences in the removal rates are discussed in terms of the absorption coefficient at each wavelength and effects of photoabsorption by N2 at 146 nm. By the addition of a small amount of O2 into an N2O/N2 mixture, the removal rate of N2O at 146 nm decreased greatly. On the basis of these facts, it was concluded that the 146 nm excimer lamp is especially useful for the N2O removal in N2 at atmospheric pressure.
Nanocrystalline CaZrTi2O7 Photocatalyst Prepared by a Polymerizable Complex Method in the Presence of Cs2CO3 Flux for Water Splitting
Authors: Miseki Yugo , Saito Kenji , Kudo Akihiko
Published: February 2009

Photocatalytic and photophysical properties of CaZrTi2O7 were investigated. When the CaZrTi2O7 powder was prepared by a polymerizable complex method in the presence of Cs2CO3 flux, powder with high crystallinity and 100–300 nm of a primary particle size was obtained. The band gap of the CaZrTi2O7 powder was 3.6 eV. It showed a broad photoluminescence band around 580 nm at 77 K. Activated NiO/CaZrTi2O7 showed photocatalytic activity for water splitting into H2 and O2 under UV irradiation.
Clear Evidence Showing the Robustness of a Highly Active Oxygen-evolving Mononuclear Ruthenium Complex with an Aqua Ligand
Authors: Masaoka Shigeyuki , Sakai Ken
Published: February 2009

Experiments show that [Ru(terpy)(bpy)(OH2)]2+ is highly active as a catalyst toward oxidation of water into molecular oxygen in spite of the mononuclear character of the complex, while [Ru(terpy)(bpy)Cl]+ shows no activity at all. It is also confirmed that [Ru(terpy)(bpy)(OH2)]2+ is fairly stable under strongly oxidizing conditions in the presence of cerium(IV) ammonium nitrate, Ce(NH4)2(NO3)6, which was evidenced by spectrophotometric, mass spectrometric, and gas chromatographic analysis.
Cationic and Anionic Dinuclear Nickel Complexes [Ni(N2S2)Ni(dtc)]n (n=−1, +1) Modeling the Active Site of Acetyl-CoA Synthase
Authors: Song Yumei , Ito Mikinao , Kotera Mai , Matsumoto Tsuyoshi , Tatsumi Kazuyuki
Published: February 2009

Two dinuclear nickel complexes (Et4N)[Ni(mbpa)-Ni(dtcEt)] (1) (dtcEt = diethyldithiocarbamate) and [Ni(dadtEt)Ni(dtcMe)](BPh4) (2) (dtcMe = dimethyldithiocarbamate) have been synthesized as models for the active site of acetyl-CoA synthase (ACS). Cyclic voltammograms show that each complex exhibits a reduction wave, in which the reduction potential of the anion 1 exhibits a significant negative shift from that of the cation 2.
Arylation of Allylsilanes through Rhodium Catalysis
Authors: Omachi Haruka , Itami Kenichiro
Published: February 2009

The arylation of allylsilanes catalyzed by a rhodium complex is described. In the presence of a catalytic amount of RhCl(CO){P[OCH(CF3)2]3}2 and Ag2CO3, allyltriisopropylsilane reacts with iodoarenes in m-xylene at 120 °C to furnish the corresponding C–H bond arylation products in moderate yields.
Dehydrative Allylation of Alcohols and Deallylation of Allyl Ethers Catalyzed by [CpRu(CH3CN)3]PF6 and 2-Pyridinecarboxylic Acid Derivatives. Effect of π-Accepting Ability and COOH Acidity of Ligand on Reactivity
Authors: Tanaka Shinji , Saburi Hajime , Hirakawa Takuya , Seki Tomoaki , Kitamura Masato
Published: February 2009

2-Quinolinecarboxylic acid efficiently promotes both the dehydrative allylation of alcohols and the deallylation of allyl ethers and esters in the presence of [CpRu(CH3CN)3]PF6. Comparison of the relative reactivity of various 4-substituted 2-pyridinecarboxylic acids has revealed two linear relations with different ρ values in the Hammett plots. These phenomena can be rationalized by the balance between the π-accepting ability of the pyridine moiety and the acidity of the carboxylic acid of the 2-pyridinecarboxylic acid derivative.
Sonication-assisted Fabrication of Hierarchical Microspheres of Mg–Al Layered Double Hydroxide
Authors: Ni Xiaomin , Zheng Huagui , Shan Yanlong , Jin Xiang , Xiao Xiukun , Liao Guangxuan
Published: February 2009

Hierarchical microspheres of Mg–Al layered double hydroxide (LDH) assembled by nanosheets were fabricated in large scale through a simple sonication-assisted method in a mixed solvent of ethylene glycol and water. The MgAl-LDHs nanostructures showed much higher efficiency in decoloring the dye of Eriochrome Blue Black K than that of the conventional platelet and particulate counterparts, which could be ascribed to their relatively large surface area.
A Facile Pathway to Synthesize One-dimensional Selenium (Se) with Controllable Morphology
Authors: Yang Zhiqiang , Cingarapu Sreeram , Klabunde Kenneth J
Published: February 2009

One-dimensional selenium (Se) structures (submicro/nano rods and nanowires) were fabricated via a facile recrystallization process by dissolving bulk Se in ethylenediamine, precipitating it with ethanol, water, or ethylene glycol, then aging at room temperature. By choosing suitable precipitating solvents and adjusting the Se concentration, the morphology of the final products could be controlled.
Depolymerization of Poly(ethylene terephthalate) to Terephthalic Acid and Ethylene Glycol in High-temperature Liquid Water
Authors: Sato Osamu , Mine Eiichi , Osada Mitsumasa , Hiyoshi Norihito , Yamaguchi Aritomo , Bando Kyoko K , Masuda Yoshio , Shirai Masayuki
Published: February 2009

Poly(ethylene terephthalate) (PET) was depolymerized to ethylene glycol and terephthalic acid in high-temperature liquid water at temperature higher than 493 K and the depolymerization of PET was enhanced by the addition of terephthalic acid in the reaction system.
Superoxide dismutase, copper and zinc concentrations in platelet-rich plasma of pneumonia patients
Authors: Laškaj R , Dodig S , Čepelak I , Kuzman I
Published: February 2009

Background

The aim of this study was to analyse platelet superoxide dismutase (SOD) activities (total SOD, manganese SOD and copper zinc SOD) and copper (Cu) and zinc (Zn) concentrations during the course of community-acquired pneumonia (CAP), and to compare them between patients with normal platelet count and those who have developed reactive thrombocytosis (RT).

Methods

Platelet count, SOD activities and Cu and Zn concentrations in platelet-rich plasma were measured in patients with CAP on admission and at discharge.

Results

Post-therapeutic platelet count increased significantly from the value recorded on admission. By the end of treatment, 42% of patients developed RT. All platelet SOD activities as well as Cu concentration were significantly lower in CAP patients than in control subjects. The initial Zn concentration was greater in CAP patients compared with controls and showed a decrease at discharge. On admission, there was no difference in all SOD activities between either subgroup with normal platelet count or subgroup with RT. At discharge all SOD activities were significantly lower in patients with RT. Also, catalytic activities of those enzymes were significantly lower in both subgroups in comparison with the initial values. Post-therapeutic Cu value was lower in patients with RT in comparison with patients having normal platelet count. Zn concentration decreased significantly at discharge when compared with the initial values only in patients with RT.

Conclusion

The pattern of changes might be indicative of a certain role of platelets in antioxidant response during treatment in CAP patients.
Simultaneous measurement of urinary metanephrines and catecholamines by liquid chromatography with tandem mass spectrometric detection
Authors: Whiting M J
Published: February 2009

Background

The measurement of catecholamines and metanephrines in urine is an important diagnostic test in biochemical screening for phaeochromocytoma. Tandem mass spectrometry (MSMS) has the potential to be used in a profiling method for simultaneous assay of these analytes.

Methods

Optimal conditions were established for the MSMS detection of catecholamines (noradrenalin, adrenalin and dopamine) and metanephrines (normetanephrine and metanephrine), including commercially available isotopically labelled compounds for use as internal standards. Chromatographic separation of all five polar biogenic amines was achieved under solvent conditions that were compatible with MSMS and multiple reaction monitoring. Several types of solid-phase extraction cartridge were used to investigate clean-up conditions for urine, and acid-hydrolysates of urine, prior to LC-MSMS.

Results

Total catecholamines and metanephrines from acid-hydrolysed urines, or free catecholamines and free metanephrines from native urines, were complexed with diphenyl-boronate and recovered in high yield from polymer cartridges after elution with formic acid. Direct injection of eluates into the LC-MSMS system allowed quantitation of catecholamines and metanephrines with a run time of 6 min per sample. Biogenic amine concentrations for patient urines and quality assurance programme samples, and assay imprecision, were similar to values obtained with high-performance liquid chromatography methods, which used electrochemical detection. In normal urines, the ratio of free to total catecholamines was around three-fold higher than the ratio of free to total metanephrines.

Conclusion

The assay of urinary catecholamines and metanephrines can be achieved simultaneously using one LC-MSMS method, which is rapid and reduces labour and consumable costs for routine application.
Hyperventilation and hypophosphataemia
Authors: Datta B N , Stone M D
Published: February 2009

We describe a case where extensive investigations were utilized to identify the aetiology of hypophosphataemia in a patient presenting with non-specific symptoms. The diagnosis of hyperventilation-induced hypophosphataemia was eventually established. Hyperventilation is a relatively common cause of isolated hypophosphataemia, but is easily overlooked as a cause.
Stability of chemical and immunochemical analytes in uncentrifuged plasma samples
Authors: Leino Aila , Koivula M K
Published: February 2009

Background

The stability of analyte concentrations in plasma after prolonged contact with blood cells in uncentrifuged lithium-heparin gel tubes was studied.

Methods

To investigate the stability of concentrations of 26 chemistry and 15 immunochemistry analytes, the simultaneously drawn samples ( n = 50) were measured after 6 h storage at +8°C and +22°C in whole blood and after immediate separation of plasma. The analyte concentrations were measured with a Roche Modular PPEE analyser using reagents from Roche Diagnostics.

Results

After prolonged contact with cells a clinically significant change was only observed for potassium where the mean value increased from 4.0 mmol/L to 4.8 mmol/L ( P < 0.001) when stored at +8°C.

Conclusion

Immediate separation of plasma from cells is recommended. However, when prolonged contact of plasma with cell is unavoidable, samples can be kept uncentrifuged for up to 6 h at +8°C or at +22°C. The stability of potassium, however, is temperature-dependent and cannot be measured from refrigerated blood samples.
Identification and comparative analysis of telomerase RNAs from Candida species reveal conservation of functional elements
Authors: Gunisova Stanislava , Elboher Elhanan , Nosek Jozef , Gorkovoy Valentin , Brown Yogev , Lucier Jean-Francois , Laterreur Nancy , Wellinger Raymund J. , Tzfati Yehuda , Tomaska Lubomir
Published: February 2009

The RNA component of telomerase (telomerase RNA; TER) varies substantially both in sequence composition and size (from ∼150 nucleotides [nt] to >1500 nt) across species. This dramatic divergence has hampered the identification of TER genes and a large-scale comparative analysis of TER sequences and structures among distantly related species. To identify by phylogenetic analysis conserved sequences and structural features of TER that are of general importance, it is essential to obtain TER sequences from evolutionarily distant groups of species, providing enough conservation within each group and enough variation among the groups. To this end, we identified TER genes in several yeast species with relatively large (>20 base pairs) and nonvariant telomeric repeats, mostly from the genus Candida. Interestingly, several of the TERs reported here are longer than all other yeast TERs known to date. Within these TERs, we predicted a pseudoknot containing U-A·U base triples (conserved in vertebrates, budding yeasts, and ciliates) and a three-way junction element (conserved in vertebrates and budding yeasts). In addition, we identified a novel conserved sequence (CS2a) predicted to reside within an internal-loop structure, in all the budding yeast TERs examined. CS2a is located near the Est1p-binding bulge-stem previously identified in Saccharomyces cerevisiae. Mutational analyses in both budding yeasts S. cerevisiae and Kluyveromyces lactis demonstrate that CS2a is essential for in vivo telomerase function. The comparative and mutational analyses of conserved TER elements reported here provide novel insights into the structure and function of the telomerase ribonucleoprotein complex.
Genome-wide identification of targets of the drosha–pasha/DGCR8 complex
Authors: Kadener Sebastian , Rodriguez Joseph , Abruzzi Katharine Compton , Khodor Yevgenia L. , Sugino Ken , Marr Michael T. , Nelson Sacha , Rosbash Michael
Published: February 2009

Drosha is a type III RNase, which plays a critical role in miRNA biogenesis. Drosha and its double-stranded RNA-binding partner protein Pasha/DGCR8 likely recognize and cleave miRNA precursor RNAs or pri-miRNA hairpins cotranscriptionally. To identify RNAs processed by Drosha, we used tiling microarrays to examine transcripts after depletion of drosha mRNA with dsRNA in Drosophila Schneider S2 cells. This strategy identified 137 Drosha-regulated RNAs, including 11 putative pri-miRNAs comprising 15 annotated miRNAs. Most of the identified pri-miRNAs seem extremely large, >10 kb as revealed by both the Drosha knock-down strategy and by RNA PolII chromatin IP followed by Drosophila tiling microarrays. Surprisingly, more than a hundred additional RNAs not annotated as miRNAs are under Drosha control and are likely to be direct targets of Drosha action. This is because many of them encode annotated genes, and unlike bona fide pri-miRNAs, they are not affected by depletion of the miRNA processing factor, dicer-1. Moreover, application of the evofold analysis software indicates that at least 25 of the Drosha-regulated RNAs contain evolutionarily conserved hairpins similar to those recognized by the Drosha–Pasha/DGCR8 complex in pri-miRNAs. One of these hairpins is located in the 5′ UTR of both pasha and mammalian DGCR8. These observations suggest that a negative feedback loop acting on pasha mRNA may regulate the miRNA-biogenesis pathway: i.e., excess Drosha cleaves pasha/DGCR8 primary transcripts and leads to a reduction in pasha/DGCR8 mRNA levels and Pasha/DGCR8 synthesis.
Information Sharing and Order Variability Control Under a Generalized Demand Model
Authors: Chen Li , Lee Hau L.
Published: February 2009

The value of information sharing and how it could address the bullwhip effect have been the subject of studies in the literature. Most of these studies used different forms of demand models, assuming that no order smoothing was used by the retailer and that the supplier has full knowledge of the retailer's demand model and order policy. In this paper, we contribute to the literature by starting with a most general demand model, coupled with a smoothing policy for order variability control. In addition, we do not require that the supplier has full knowledge of the retailer's demand model and order policy, but instead let the retailer share its projected future orders (and freely revise them as the retailer sees fit). Under such a setting, we first obtain a unifying formula for the magnitude of the bullwhip effect. The formula indicates that it is the forecast correlation over the exposure period as a whole that determines the magnitude of the bullwhip effect. We then quantify the value of information sharing and generalize the existing results in the literature. Finally, we explore the optimal smoothing parameters that could benefit the total supply chain. The resulting optimal policy resembles the postponement strategy. We find that information sharing together with order postponement improves the supply chain performance, even though the order variability may amplify in some cases.
Optimal Market Intelligence Strategy When Management Attention Is Scarce
Authors: Christen Markus , Boulding William , Staelin Richard
Published: February 2009

This paper extends the theoretical literature on firms' optimal information strategies to the situation when a firm's management attention capacity to process available data is scarce. In this case, a firm's optimal market intelligence strategy must trade off learning a little about a broad range of markets (a broad strategy) with gaining a very deep understanding of one or a few markets (a focused strategy). This trade-off is not present when data are scarce, an assumption made in most of the existing literature on optimal information search strategies. However, in data-rich environments, which are of increasing relevance given technology changes, we show a focused market intelligence strategy is always best when managers need to process a substantial amount of data before beginning to gain insights; i.e., there are increasing returns to attention. Interestingly, this focused strategy can also be best with decreasing returns to attention when (a) managers are sufficiently efficient in processing the available data and (b) managers have sufficiently strong initial priors on the unknown market parameters. We show a broad market intelligence strategy is only optimal when new data points are sufficiently redundant, i.e., when the learning rate is sufficiently decreasing with the allocation of more attention. Our results also indicate that advances in information technology can account for the pressure on firms to become more focused and that competition increases the likelihood of a focused strategy. Competition can lead to asymmetric outcomes where firms focus on different markets. Finally, we note that a focused market intelligence strategy, and thus an asymmetric allocation of attention, does not require a priori differences between firms, markets, or market-specific core capabilities. Consequently, a focused market intelligence strategy can result in market-specific core competencies and produce firm differences from equivalent starting conditions.
Antibody Elution Method for Multiple Immunohistochemistry on Primary Antibodies Raised in the Same Species and of the Same Subtype
Authors: Pirici Daniel , Mogoanta Laurentiu , Kumar-Singh Samir , Pirici Ionica , Margaritescu Claudiu , Simionescu Cristina , Stanescu Radu
Published: February 2009

Double or multiple antigen labeling in IHC classically relies on the existence of primary antibodies raised in different species or of different IgG isotypes to ensure the specific labeling with the secondary detection systems. However, suitable pairs of primary antibodies are not always available or the best choice (e.g., as diagnostic tools). During the last few years, several methods have been proposed to overcome this, but none of them offers the flexibility needed for reliable double or multiple enzymatic or fluorescent IHC. We present here a procedure that elutes the antibodies after a first round of immunolabeling, which, in combination with precipitation-based detection systems, allows multiple IHC rounds even for primary antibodies raised in the same species and IgG isotype. Compared with other proposed methods, this procedure ensures a reliable enzymatic or fluorescent staining without cross-reactivity and without loss of tissue antigenicity, thus offering a flexible tool for colocalization studies and pathological diagnosis. This manuscript contains online supplemental material at http://www.jhc.org . Please visit this article online to view these materials.
Modern Nanotemplates Based on Graphene and Single Layer h-BN
Authors: Goriachko A. , Over H.
Published: February 2009

This mini-review focuses on the recently discovered nanomeshes and nanotemplates made from carbon, boron nitride and their mixtures with a thickness of just a single atomic layer. Typically they exist on some transition metal or semiconductor substrate, the interaction with it playing a crucial role in nanopattern formation. We review systems such as graphene/SiC(0001), graphene/Ru(0001), h-BN/Ru(0001), and h-BN/Rh(111), their atomistic models, synthesis routes, as well as possible applications as templates for nanoperiodic arrays of clusters and molecules. Scanning tunneling microscopy (STM), a technique with ultimate resolution in real space, is stressed as an indispensable tool for a comprehensive characterization of the given systems.
On the CO-Oxidation over Oxygenated Ruthenium
Authors: Rosenthal Dirk , Girgsdies Frank , Timpe Olaf , Blume Raoul , Weinberg Gisela , Teschner Detre , Schlögl Robert
Published: February 2009

The oxidation of carbon monoxide over polycrystalline ruthenium dioxide (RuO2) powder was studied in a packed-bed reactor and by bulk and surface analytical methods. Activity data were correlated with bulk phases in an in-situ X-ray diffraction (XRD) setup at atmospheric pressure. Ruthenium dioxide was pre-calcined in pure oxygen at 1073 K. At this stage RuO2 is completely inactive in the oxidation of CO. After a long induction period in the feed at 503 K RuO2 becomes active with 100% conversion, while in-situ XRD reveals no changes in the RuO2 diffraction pattern. At this stage selective roughening of apical RuO2 facets was observed by scanning electron microscopy (SEM). Seldom also single lateral facets are roughened. EDX indicated higher oxygen content in the following order: flat lateral facets > rough lateral facets > rough apical facets. Further, experiments in the packed bed reactor indicated oscillations in the CO2 formation rate. At even higher temperatures in reducing feed (533–543 K) the sample reduces to ruthenium metal according to XRD. The reduced particles exhibiting lower ignition temperature are very rough with cracks and deep star-shaped holes. An Arrhenius plot of the CO2 formation rate below the ignition temperature reveals the reduced samples to be significantly more active based on mass unit and shows lower apparent activation energy than the activated oxidized sample. Micro-spot X-ray photoelectron spectroscopy (XPS) and XPS microscopy experiments were carried out on a Ru(0001) single crystal exposed to oxygen at different temperature. Although low energy electron diffraction (LEED) images show a strong 1×1 pattern, the XPS data indicated a wide lateral inhomogeneity with different degree of oxygen dissolved in the subsurface layers. All these and the literature data are discussed in the context of different active states and transport issues, and the metastable nature of a phase mixture under conditions of high catalytic activity.
Beethoven in B♭: Op. 130 and the Hammerklavier
Authors: Lambert Sterling
Published: February 2009

Commentators have sometimes remarked on similarities between contemporaneous piano sonatas and quartets by Beethoven, as if the composer were developing ideas at the keyboard before transferring them to other genres. A particularly close connection can be seen, however, between two works in B♭ major that are separated by a greater distance in time: the Piano Sonata in B♭, op. 106 (Hammerklavier) and the String Quartet in B♭, op. 130. Correspondences between the respective first movements are particularly strong, and they suggest that the sonata may have served as something of model for the quartet.

Yet the same elements that contribute to a highly integrated structure in the sonata seem to serve quite different purposes in a quartet characterized by a pointed disintegration of normative procedures. A comparison of the two works shows not only how Beethoven's style underwent significant change in the intervening time, but also how the quartet may serve as a critique of the sonata in an act of deliberate stylistic distancing. This brings into question the well established concept of a unified “late” or “third-period” style.
Lead Toxicity: Does the Critical Level of Lead Resulting in Adverse Effects Differ between Adults and Children?
Authors: Murata Katsuyuki , Iwata Toyoto , Dakeishi Miwako , Karita Kanae
Published: February 2009

Lead Toxicity: Does the Critical Level of Lead Resulting in Adverse Effects Differ between Adults and Children?: Katsuyuki Murata, et al. Department of Environmental Health Sciences, Akita University School of Medicine

Objectives

The Scientific Committee on Neurotoxicology and Psychophysiology and the Scientific Committee on the Toxicology of Metals of the International Commission on Occupational Health in 2006 recommended that the standard for blood lead (BPb) levels be reduced to 30 µg/dl for industrial workers and 5 µg/dl for children. To examine whether the critical level of lead producing adverse effects truly differs between workers and children, we provided an overview of studies addressing the critical level of lead in workers, together with a perspective on lead toxicity in children.

Data sources and extraction

In 25 reports published in English with keywords of “benchmark dose (BMD),” “lead” and “humans,” only five studies proved to be relevant to lead toxicity. Four more studies with figures illustrating significant relationships between lead and neurotoxic outcomes were selected.

Data synthesis

Based on data from previous reports using a BMD approach, the critical organ of lead in workers was thought to be the nervous system and the critical BPb level (number‐weighted mean) was between 10.7 and 17.5 µg/dl. The neurotoxic effects of lead exposure at such levels seemed reversible. The BPb level at which lead‐associated intellectual deficits occurred in children was as low as the critical level of BPb (below 5 µg/dl) for inhibited heme synthesis in workers.

Conclusions

The neurotoxic effects of lead in workers appear to be initiated at BPb levels below 18 µg/dl, which are somewhat higher than the critical level of lead neurotoxicity in children. Each national institute for risk management should take evidence‐based preventive action against subclinical lead poisoning in workers, as well as in children.
The Effect of Smoking Prevalence at Worksites on Individual Cessation Behavior
Authors: Nishiura Chihiro , Narai Rie , Ohguri Takayuki , Funahashi Atsushi , Yarita Keiichirou , Hashimoto Hideki
Published: February 2009

The Effect of Smoking Prevalence at Worksites on Individual Cessation Behavior: Chihiro Nishiura, et al. Department of Safety and Health, Tokyo Gas Co., Ltd.

Objectives

To identify the effect of worksite smoking prevalence on individual cessation behavior.

Methods

We conducted a cohort study at a Japanese worksite without a total ban on smoking, but with designated smoking areas. Baseline data were obtained in 2005 through a self‐administered questionnaire from 15,229 workers in 322 work units as part of annual health checkups, and followed up in 2006. Data on smoking status, time to first cigarette after waking up, desire to quit, number of cigarettes smoked per day, and respiratory symptoms were obtained. Details like workers' demographics, blue/ white‐collar workers, night shift duties, administrative position, and work unit codes were obtained from the firm's administrative records. Smoking prevalence in work units was calculated as a ratio, standardized by age, and categorized into quartiles. Multiple logistic regression was used to predict cessation by smoking prevalence, adjusting for individual level variables.

Results

In the lowest smoking prevalence quartile compared with the highest, odds ratios (95% CI) of cessation among those who smoked their first cigarette more than 30 min after waking up were 2.32 (1.06, 5.09) in white‐collar units and 1.86 (0.98, 3.55) in blue‐collar units, and that among those with a moderate desire to quit was 2.05 (0.94, 4.49) in white‐collar units.

Conclusion

Worksite smoking prevalence affects the likelihood of successful cessation, especially among those with less nicotine dependence and who are in the early stage of behavioral change. This suggests that serious consideration should be placed not only on individual behavior modification but also on modification of worksite conditions.
Oral Lead Exposure Induces Dysbacteriosis in Rats
Authors: Sadykov Rustam , Digel Ilya , Artmann Aysegül Temiz , Porst Dariusz , Linder Peter , Kayser Peter , Artmann Gerhard , Savitskaya Irina , Zhubanova Azhar
Published: February 2009

Oral Lead Exposure Induces Dysbacteriosis in Rats: Rustam Sadykov,et al. Laboratory of Cellular Biophysics, Aachen University of Applied Sciences, Germany

Objectives

Lead's (Pb(II)) possible role in intestinal pathologies of microbial etiology remains mostly unknown. The aim of this study was to examine the effects of lead on the gut microbial community and its interactions with rat intestinal epithelium.

Methods

The lead‐induced changes in different intestinal microbial groups (lactose‐positive lac(+) and ‐negative lac(–)E.colistrains, lactobacilli and yeasts) were followed separately by the colony‐forming unit (CFU) method. Samples were taken from outbred white rats subjected to different exposure schedules. Additionally, the impact of different lead doses on microbial adhesion to cultured intestinal cells (IEC‐6) was investigated. Finally, the lead accumulation and distribution were measured by means of atomic absorption spectrometry.

Results

For the first time it was shown that oral lead exposure causes drastic changes in the gut microbial community. Proportional to the lead dose received, the relative number of lactose‐negativeE.colicells increased dramatically (up to 1,000‐fold) in comparison to the other microbial groups during 2 wk of exposure. Considering the number of microbes in the intestine, such a shift in intestinal microflora (dysbacteriosis) is very significant. Adhesion studies showed certain stimulating effects of lead onE.coliattachment to rat intestinal epithelium as compared toLactobacillusattachment.

Conclusions

The mechanisms providing the apparent competitive success of the lac(–) group are unclear but could be related to changes in surface interactions between microbial and host cells. This study may provide important clues for understanding the pathological effects of metal dietary toxins in human beings.