bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wintertime Vitamin D Supplementation Inhibits Seasonal Variation of Calcitropic Hormones and Maintains Bone Turnover in Healthy Men
Authors: Viljakainen Heli T , Väisänen Milja , Kemi Virpi , Rikkonen Toni , Kröger Heikki , Laitinen E Kalevi A , Rita Hannu , Lamberg-Allardt Christel 
Published: October 2008

Abstract
Vitamin D is suggested to have a role in the coupling of bone resorption and formation. Compared with women, men are believed to have more stable bone remodeling, and thus, are considered less susceptible to the seasonal variation of calcitropic hormones. We examined whether seasonal variation exists in calcitropic hormones, bone remodeling markers, and BMD in healthy men. Furthermore, we determined which vitamin D intake is required to prevent this variation. Subjects (N = 48) were healthy white men 21–49 yr of age from the Helsinki area with a mean habitual dietary intake of vitamin D of 6.6 ± 5.1 (SD) μg/d. This was a 6-mo double-blinded vitamin D intervention study, in which subjects were allocated to three groups of 20 μg (800 IU), 10 μg (400 IU), or placebo. Fasting blood samplings were collected six times for analyses of serum (S-)25(OH)D, iPTH, bone-specific alkaline phosphatase (BALP), and TRACP. Radial volumetric BMD (vBMD) was measured at the beginning and end of the study with pQCT. Wintertime variation was noted in S-25(OH)D, S-PTH, and S-TRACP (p &lt; 0.001, p = 0.012, and p &lt; 0.05, respectively) but not in S-BALP or vBMD in the placebo group. Supplementation inhibited the winter elevation of PTH (p = 0.035), decreased the S-BALP concentration (p &lt; 0.05), but benefited cortical BMD (p = 0.09) only slightly. Healthy men are exposed to wintertime decrease in vitamin D status that impacts PTH concentration. Vitamin D supplementation improved vitamin D status and inhibited the winter elevation of PTH and also decreased BALP concentration. The ratio of TRACP to BALP shows the coupling of bone remodeling in a robust way. A stable ratio was observed among those retaining a stable PTH throughout the study. A daily intake of vitamin D in the range of 17.5–20 μg (700–800 IU) seems to be required to prevent winter seasonal increases in PTH and maintain stable bone turnover in young, healthy white men.
Effect of Lamin A/C Knockdown on Osteoblast Differentiation and Function
Authors: Akter Rahima , Rivas Daniel , Geneau Graziello , Drissi Hicham , Duque Gustavo 
Published: October 2008

Abstract
Recent studies have associated mutations in lamin A/C, a component of the nuclear lamina, with premature aging and severe bone loss. In this study, we hypothesized that reduced expression of lamin A/C has a negative impact on osteoblastogenesis and bone formation in vitro. We inhibited lamin A/C using increasing doses of lamin A/C siRNA in normal human osteoblasts and differentiating mesenchymal stem cells (MSCs). Untreated cells and cells treated with vehicle but without the siRNA-oligo were used as control. The level of effectiveness of siRNA was determined by RT-PCR, Western blot, and immunofluorescence. Nuclear blebbing, a typical finding of lamin A/C inhibition, was quantified using propidium iodine staining, and its effect on cell survival was determined using MTS-formazan. Furthermore, alizarin red and alkaline phosphatase staining were correlated with osteocalcin secretion and levels of expression of osteocalcin, osterix, bone sialoprotein, and Runx2. Finally, the nuclear binding activity of Runx2, an essential transcription factor for osteoblast differentiation, was assessed using ELISA and EMSA. A successful inhibitory effect on the lamin A/C gene at doses of 400–800 nM oligo was obtained without affecting cell survival. Whereas osteoblast function was significantly affected by lamin A/C inhibition, siRNA-treated MSC showed a higher incidence of nuclear changes, lower osteoblast differentiation, and enhanced adipocyte differentiation. Finally, lamin A/C knockdown reduced Runx2 nuclear binding activity without affecting Runx2 expression. In summary, our results indicate that lamin A/C is a new factor needed for osteoblast differentiation that plays an important role in the cellular mechanisms of age-related bone loss.
Critical Interplay Between Neuropeptide Y and Sex Steroid Pathways in Bone and Adipose Tissue Homeostasis
Authors: Allison Susan J , Baldock Paul A , Enriquez Ronaldo F , Lin EnJu , During Matthew , Gardiner Edith M , Eisman John A , Sainsbury Amanda , Herzog Herbert 
Published: October 2008

Abstract
Important and novel roles for neuropeptide Y (NPY) signaling in the control of bone homeostasis have recently been identified, with deletion of either the Y1 or Y2 receptors resulting in a generalized increase in bone formation. Whereas the Y2 receptor-mediated anabolic response is mediated by a hypothalamic relay, the Y1-mediated response is likely mediated by osteoblastic Y1 receptors. The presence of Y1 receptors on osteoblasts and various other peripheral tissues suggests that, in addition to neuronal input, circulating factors may also interact with the Y1-mediated pathways. The skeletal and adipose tissue (peripheral and marrow) responses to Y1 receptor deficiency were examined after (1) leptin deficiency, (2) gonadectomy, and (3) hypothalamic NPY overexpression. Bone formation was consistently increased in intact Y1−/− mice. However, the hypogonadism of gonadectomy or leptin deficiency blocked this anabolism in male Y1−/− mice, whereas females remained unchanged. The Y1-mediated bone anabolic pathway thus seems to be dependent on the presence of intact androgen signaling. Y1 deficiency also led to increased body weight and/or adiposity in all experimental models, with the exception of male ob/ob, showing a general adipogenic effect of Y1 deficiency that is not dependent on androgens. Interestingly, marrow adipocytes were regulated differently than general adipose depots in these models. Taken together, this interaction represents a novel mechanism for the integration of endocrine and neural signals initiated in the hypothalamus and provides further insight into the coordination of bone and energy homeostasis.
Metabolic Acidosis Increases Intracellular Calcium in Bone Cells Through Activation of the Proton Receptor OGR1
Authors: Frick Kevin K , Krieger Nancy S , Nehrke Keith , Bushinsky David A 
Published: October 2008

Abstract
Metabolic acidosis increases urine Ca without increasing intestinal absorption, leading to bone Ca loss. It is unclear how bone cells detect the increase in proton concentration. To determine which G protein-coupled proton sensing receptors are expressed in bone, PCR was performed, and products were detected for OGR1, TDAG8, G2A, and GPR4. We tested the hypothesis that the G protein-coupled proton sensor, OGR1, is an H+-sensing receptor in bone. To determine whether acid-induced bone resorption involves OGR1, we incubated mouse calvariae in neutral pH (NTL) or acidic (MET) medium ± the OGR1 inhibitor CuCl2. CuCl2 decreased MET-induced Ca efflux. We used fluorescent imaging of perfused bone cells to determine whether MET increases Cai. Perfusion with MET induced a rapid, flow-independent, increase in Cai in individual bone cells. To determine whether transfection of OGR1 into a heterologous cell type would increase Cai in response to H+, we perfused Chinese hamster ovary (CHO) cells transfected with mouse OGR1 cDNA. Perfusion with MET induced a rapid increase in Cai in OGR1-transfected CHO cells. These data indicate that OGR1 induces an increase in Cai in response to MET and is a prime candidate for an osteoblast proton sensor.
Analytical Characteristics of Commercial Cardiac Troponin I and T Immunoassays in Serum from Rats, Dogs, and Monkeys with Induced Acute Myocardial Injury
Authors: Apple Fred S , Murakami MaryAnn M , Ler Ranka , Walker Dana , York Malcolm ,   for the HESI Technical Committee of Biomarkers Working Group on Cardiac Troponins
Published: October 2008

AbstractBackground: Information is needed regarding analytical characteristics of cardiac troponin (cTn) assays used in preclinical studies.Methods: We measured cTnI and cTnT in serum from normal animals and animals with induced myocardial injury [Sprague–Dawley (SD) and Wistar rats, beagle dogs, and rhesus (Rh) and cynomolgus (Cy) monkeys]. We evaluated the following assays: for cTnI, Abbott Architect, Bayer Centaur (first and second generation), Beckman Access, DPC Immulite, Dade Dimension, Ortho Vitros ES, Tosoh AIA, and species-specific enzyme immunoassays; for cTnT, Roche Elecsys.Results: We found different species-specific responses for the troponin assays evaluated. Abbott, Bayer Ultra, Beckman, and Dade assays gave good responses across all species. In rats, weak responses were observed with DPC and Ortho, and no measurable response with Tosoh. In dogs, weak responses were observed with Tosoh cTnI, Roche cTnT, and species-specific cTnI. In cynomolgus monkeys, weak responses were observed with species-specific cTnI and Roche cTnT. Assay imprecision was ≤20% at 3 or more examined cTn concentrations for Beckman (rat, dog, monkey), Dade (rat, dog, monkey), Abbott (rat, dog, monkey), Bayer first generation (dog), Bayer Ultra (rat, dog, monkey), Roche (monkey), DPC (dog, monkey), Ortho (dog, monkey), and Tosoh (dog, monkey) assays, whereas imprecision was ≤20% at 2 or fewer concentrations for the Bayer first generation (rat, monkey), Roche cTnT (rat, dog), and DPC (rat) assays.Conclusions: Not all cTn assays are suitable for monitoring cTn in each animal species or strain. Individual assay characterization by animal species is needed to prevent misinterpretation of myocardial injury–based cardiac troponin findings.
Meconium Nicotine and Metabolites by Liquid Chromatography-Tandem Mass Spectrometry: Differentiation of Passive and Nonexposure and Correlation with Neonatal Outcome Measures
Authors: Gray Teresa R , Magri Raquel , Shakleya Diaa M , Huestis Marilyn A 
Published: October 2008

AbstractBackground: Meconium analysis is a diagnostically sensitive and objective alternative to maternal self-report for detecting prenatal tobacco exposure. Nicotine and metabolite disposition in meconium is poorly characterized, and correlation of analytes’ concentrations with neonatal outcomes is unexplored. Our objectives were to quantify nicotine, cotinine, trans-3′-hydroxycotinine (OH-cotinine), nornicotine, norcotinine, and glucuronide concentrations in meconium, identify the best biomarkers of in utero tobacco exposure, compare meconium concentrations of tobacco-exposed and nonexposed neonates, and investigate concentration-outcome relationships.Methods: We quantified concentrations of nicotine and 4 metabolites with and without hydrolysis simultaneously in meconium from tobacco-exposed and nonexposed neonates by liquid chromatography-tandem mass spectrometry. We compared meconium concentrations to birth weight, length, head circumference, gestational age, and 1- and 5-min Apgar scores.Results: Nicotine, cotinine, and OH-cotinine were the most prevalent and abundant meconium tobacco biomarkers and were found in higher concentrations in tobacco-exposed neonates. Whereas cotinine and OH-cotinine are glucuronide bound, performing the lengthy and costly enzymatic hydrolysis identified only 1 additional positive specimen. Unconjugated nicotine, cotinine, or OH-cotinine meconium concentration &gt;10 ng/g most accurately discriminated active from passive and nonexposed neonates. There was no significant correlation between quantitative nicotine and metabolite meconium results and neonatal outcomes, although presence of a nicotine biomarker predicted decreased head circumference.Conclusions: Unconjugated nicotine, cotinine, and OH-cotinine should be analyzed in meconium to detect in utero tobacco exposure, as approximately 25% of positive specimens did not contain cotinine. Immunoassay testing monitoring cotinine only would underestimate the prevalence of prenatal tobacco exposure.
Tryptic Peptide Analysis of Ceruloplasmin in Dried Blood Spots Using Liquid Chromatography–Tandem Mass Spectrometry: Application to Newborn Screening
Authors: deWilde Amy , Sadilkova Katerina , Sadilek Martin , Vasta Valeria , Hahn Si Houn 
Published: October 2008

AbstractBackground: Newborn screening to identify infants with treatable congenital disorders is carried out worldwide. Recent tandem mass spectrometry (MS/MS) applications have markedly expanded the ability to screen for &gt;50 metabolic diseases with a single dried blood spot (DBS). The feature that makes metabolic disorders particularly amenable to screening is the presence of specific small-molecule metabolites. Many treatable disorders such as Wilson disease, however, are characterized by absent or diminished large proteins in plasma or within circulating blood cells, for which there are currently no cost-effective screening methods.Methods: We developed an assay for quantifying ceruloplasmin (CP) in DBS for newborn screening of Wilson disease. CP-specific peptides from DBS samples digested by trypsin were quantified using isotopically labeled peptide internal standards and liquid chromatography–triple quadrupole mass spectrometry (LC-MS/MS).Results: The calibration curve was linear from 20 to 95 mg/dL (200–950 mg/L). Intraassay imprecision (mean CV) for CP concentrations of 25, 35, and 55 mg/dL (250, 350, and 550 mg/L) was 9.2%, 10.7%, and 10.2%, respectively. Interassay imprecision for 19 different batches was 8.9%, 5.8%, and 6.9%. A method comparison study on previously tested patient samples for CP gave comparable results with lower limit of quantification, around 0.7 mg/dL (7 mg/L).Conclusions: Our study supports that newborn screening for Wilson disease is feasible using LC-MS/MS assay for CP quantification in DBS after tryptic digestion. This approach should be applicable to newborn screening for other treatable genetic conditions, such as primary immunodeficiencies, that have large proteins as biomarkers.
Enumerating and identifying semiperfect colorings of symmetrical patterns
Authors: Felix Rene P. , Loquias Manuel Joseph C. 
Published: October 2008

Abstract
If G is the symmetry group of an uncolored pattern then a coloring of the pattern is semiperfect if the associated color group H is a subgroup of G of index 2. We give results on how to identify and enumerate all inequivalent semiperfect colorings of certain patterns. This is achieved by treating a coloring as a partition {hJiYi : i ∈ I, h ∈ H} of G, where H is a subgroup of index 2 in G, Ji
≤ H for i ∈ I, and Y = ∪
i∈I

Yi
is a complete set of right coset representatives of H in G. We also give a one-to-one correspondence between inequivalent semiperfect colorings whose associated color groups are conjugate subgroups with respect to the normalizer of G in the group of isometries of
R

n
.
Combined powder diffraction and solid-state DFT study of [Cu (2,6-dimethoxynicotinate)2(μ-ronicol)2]
n
complex
Authors: Jorik Vladimir , Scholtzová Eva , Segl'a Peter 
Published: October 2008

Abstract
Crystal structure of the title compound was solved from the laboratory powder diffraction data in the P21/c space group. Because Rietveld refinement yielded inaccurate geometry of the structural moieties the structure was finally refined by means of geometry optimization using DFT/plane waves approach in the solid state. The asymmetric unit of [Cu{2,6-(MeO)2nic}2(μ-ron)2]
n
consists of the copper(II) atom located on an inversion centre, one 2,6-dimethoxynicotinate anion and one ronicol molecule which acts as a bridging ligand coordinated via oxygen atom of the hydroxymethyl group as well as the nitrogen atom of the pyridine ring – μ-ron = bridging 3-pyridylmethanol. Each copper (II) complex unit is connected to the other four units through the ronicol ligands forming 2D sheets running parallel to the bc plane. The structure is stabilized by a strong intramolecular hydrogen bond O—H…O and supported by weak C—H…O hydrogen bonds.
Crystal structure of a new homo trinuclear Ni(II) complex with μ-cyanoacetato bridge
Authors: Ates B. Meltem , Ercan Filiz , Aksu M. Levent , Atakol Orhan 
Published: October 2008

Abstract
Ni(II)-Ni(II)-Ni(II) homo-trinuclear linear complex was prepared using bis-N,N′(2-hydroxybenzyl)-1,3-propanediamine in DMF (dimethyl formamide) medium. μ-bridges between metal nuclei are formed using formate, acetate, chloroacetate and benzoate ions. The structure of the homo-trinuclear complex was determined with X-ray diffraction method. It was found that the terminal Ni(II) ions have a N2O4 coordination sphere and central Ni(II) ion has a O6 octahedral coordination sphere. The chelate ring, formed by the coordination of terminal Ni atoms and aminic nitrogen atoms, was found to have a chair conformation. The complexes were elucidated by the use of thermogravimetry and differential thermal analysis method. In acetate, chloroacetate, cyanoacetate and benzoate containing complexes thermal dissociation of DMF took place first while in formate containing complex it was observed that formate bridges and the complex degraded together with the dissociation of DMF moiety. It was observed that the thermal stability of carboxylate μ-bridge affects the thermal stability of the homo-nuclear complex. The average bond energies of coordinated DMF molecules were determined and these coordinative bond energies were found to be in the dimension of that of hydrogen bonds.
Crystal and molecular structures of dichloro((Z)-2-chloro-2-phenylvinyl)(organo)tellurium(IV) for organo = n-butyl and phenyl
Authors: Zukerman-Schpector Julio , Stefani Hélio Alexandre , Guadagnin Rafael C. , Suganuma Carlos A. , Tiekink Edward R. T. 
Published: October 2008

Abstract
In each of the title compounds, R[Ph(Cl)C=(H)C]TeCl2, R = nBu (1) and Ph (2), the primary geometry about the TeIV atom is a pseudo-trigonal-bipyramidal arrangement, with two Cl atoms in apical positions, and the lone pair of electrons and C atoms in the equatorial plane. As the TeIV is involved in two, an intra- and an inter-molecular, Te···Cl interactions the coordination geometry might be considered as a ψ-pentagonal bipyramid in each case. In addition, in (2) there is a hint of a Te···π interaction (Te···C = 3.911(3) Å). The key feature in the crystal structure of both compounds is the formation of supramolecular chains mediated by Te···Cl contacts.(1): C12H15Cl3Te, triclinic, P-1, a = 5.9471(11), b = 10.7826(22), c = 11.7983(19) Å, α = 75.416(12), β = 78.868(13), γ = 80.902(14)°, V = 713.6(2) Å3, Z = 2, R
1 = 0.021; (2): C14H11Cl3Te, orthorhombic, Pcab, a = 7.7189(10), b = 17.415(2), c = 21.568(3) Å, V = 2899.3(6) Å3, Z = 8, R
1 = 0.027.
Serum levels of adipocyte fatty acid binding protein are increased in gestational diabetes mellitus
Authors: Kralisch Susan , Stepan Holger , Kratzsch Jürgen , Verlohren Michael , Verlohren Hans-Joachim , Drynda Kathrin , Lössner Ulrike , Blüher Matthias , Stumvoll Michael , Fasshauer Mathias 
Published: October 2008

ObjectiveAdipocyte fatty acid binding protein (AFABP) was recently introduced as a novel adipokine, serum levels of which independently correlate with the development of the metabolic syndrome and cardiovascular disease in humans. In the current study, we investigated serum concentrations of AFABP in patients with gestational diabetes mellitus (GDM) as compared with healthy pregnant controls matched for gestational age and fasting insulin.Design and methodsAFABP was determined by ELISA in controls (n=80) and GDM patients (n=40) and correlated to clinical and biochemical measures of renal function, glucose and lipid metabolism, as well as inflammation, in both groups.ResultsMedian serum AFABP concentrations were significantly elevated in subjects with GDM (22.9 μg/l) as compared with healthy pregnant controls (18.3 μg/l; P<0.05). Furthermore, GDM was independently associated with AFABP concentrations in multiple regression analysis (P<0.05). In addition, markers of adiposity (body mass index, serum leptin), triglycerides and serum creatinine were independently associated with circulating AFABP (P<0.05).ConclusionsMaternal AFABP concentrations are significantly increased in GDM. The adipokine might contribute to the increased metabolic and cardiovascular risk of the disease.
A Yeast Sir2 Mutant Temperature Sensitive for Silencing
Authors: Wang Chia-Lin , Landry Joseph , Sternglanz Rolf 
Published: October 2008

Abstract
A screen for Saccharomyces cerevisiae temperature-sensitive silencing mutants identified a strain with a point mutation in the SIR2 gene. The mutation changed Ser276 to Cys. This amino acid is in the highly conserved NAD+ binding pocket of the Sir2 family of proteins. Haploid strains of either mating type carrying the mutation were severely defective at mating at 37° but normal at 25°. Measurements of RNA from the HMR locus demonstrated that silencing was lost rapidly upon shifting the mutant from the low to the high temperature, but it took &gt;8 hours to reestablish silencing after a shift back to 25°. Silencing at the rDNA locus was also temperature sensitive. On the other hand, telomeric silencing was totally defective at both temperatures. Enzymatic activity of the recombinant wild-type and mutant Sir2 protein was compared by three different assays. The mutant exhibited less deacetylase activity than the wild-type protein at both 37° and 25°. Interestingly, the mutant had much more NAD+–nicotinamide exchange activity than wild type, as did a mutation in the same region of the protein in the Sir2 homolog, Hst2. Thus, mutations in this region of the NAD+ binding pocket of the protein are able to carry out cleavage of NAD+ to nicotinamide but are defective at the subsequent deacetylation step of the reaction.
A Feeder-Free and Efficient Production of Functional Neutrophils from Human Embryonic Stem Cells
Authors: Saeki Koichi , Saeki Kumiko , Nakahara Masako , Matsuyama Satoko , Nakamura Naoko , Yogiashi Yoshiko , Yoneda Asako , Koyanagi Makoto , Kondo Yasushi , Yuo Akira 
Published: October 2008

AbstractA novel, feeder-free hematopoietic differentiation protocol was established for highly efficient production of neutrophils from human embryonic stem cells (hESCs). For the induction of differentiation, spheres were generated in the presence of serum and cytokine cocktail and subjected to attachment culture on gelatin-coated plates. After approximately 2 weeks, a sac-like structure filled with abundant round cells emerged at the center of flattened spheres. After cutting off this sac-like structure, round cells actively proliferated, either floating in the supernatant or associated weakly with the adherent cells. Almost all of these round cells were CD45-positive hematopoietic cells with myeloid phagocytic markers (CD33 and CD11b), and approximately 30%–50% of the round cells were mature neutrophils, as judged from morphology, cytochemical characteristics (myeloperoxidase and neutrophil alkaline phosphatase), and neutrophil-specific cell surface markers (CD66b, CD16b, and GPI-80). In addition, hESC-derived neutrophils had chemotactic capacity in response to the bacterial chemotactic peptide formyl-methionyl-leucyl-phenylalanine and neutrophil-specific chemokine interleukin (IL)-8. Using “semipurified” neutrophils migrated to IL-8, both phagocytic and respiratory burst activities were demonstrated. Finally, it was shown that hESC-derived neutrophils had chemotactic activity in vivo in a murine air-pouch inflammatory model. The present results indicate successful induction of functional mature neutrophils from hESCs via highly efficient feeder-free differentiation culture system of human hematopoietic cells.