bluuebunny/crossref_metadata_2025_split huggingface dataset:
Synthesis, Structure, and Polymerization Activity of Cyclopentadienylnickel(II) N‐Heterocyclic Carbene Complexes: Selective Cross‐Metathesis in Metal Coordination Spheres
Authors: Buchowicz Włodzimierz , Wojtczak Wioleta , Pietrzykowski Antoni , Lupa Anna , Jerzykiewicz Lucjan B. , Makal Anna , Woźniak Krzysztof 
Published: December 2009

AbstractThe N‐heterocyclic carbene (NHC) complexes [(RC5H4)Ni(X)(NHC)] (2–5) have been prepared by treating nickelocene [or 1,1′‐bis(alkenyl)nickelocene] with a suitable carbene precursor. The alkenylcyclopentadienido complexes 4 and 5 undergo chemoselective cross‐metathesis with methyl acrylate or methyl vinyl ketone in the presence of the seocnd‐generation Grubbs catalyst to yield complexes 6–8, which bear an α,β‐unsaturated carbonyl substituent on the cyclopentadienido ligand. The X‐ray crystal structure of 2 [monoclinic,P21/n, Ni–Ccarbene 1.879(3) Å] and 7 [triclinic, P$\bar {1}$, Ni–Ccarbene 1.8874(6) Å] reveal undistorted trigonal‐planar Ni coordination. VT‐NMR studies of complexes 2 and 3, which possess an N‐alkyl substituent, show hindered rotation of the carbene ligand. Complexes [(RC5H4)Ni(X)(NHC)], in the presence of an excess of MAO, display high activity in the polymerization of styrene and moderate activity in the oligomerization of phenylacetylene.
Synthesis of an (±)‐Estrone Precursor: The Scope of Zr‐ and Co‐Mediated Cycloannulations
Authors: Betík Robert , Herrmann Pavel , Kotora Martin 
Published: December 2009

AbstractThe synthesis of an estrone intermediate based on a new approach was studied. The construction of the basic framework was carried out in three steps from a simple styrene derivative. The crucial reaction sequence for the steroid skeleton construction relied on a Zr‐mediated cyclization (Zr‐ene reaction)/propargylation followed by a Co‐mediated diastereoselective Pauson–Khand reaction that afforded various D‐ring‐substituted tetracyclic ketones 11 with natural trans‐anti stereochemistry. The conjugated addition reaction of Me2CuLi to tetracyclic ketone 11a aiming at the installation of the angular methyl group in the 13‐position gave rise exclusively to product 12 with unnatural trans‐anti‐cis stereochemistry The successful synthesis of known estrone intermediate 4 with natural trans‐anti‐trans stereochemistry was accomplished by chemoselective reduction of the carbonyl group of ketone 11b. Attempts to use other metallo‐ene reactions to affect the synthesis of steroid B‐ring are also described.
Testing of the influenza virus purification by CIEF
Authors: Horká Marie , Kubíček Oldřich , Kubesoví Anna , Kubíčková Zuzana , Rosenbergová Kateřina , Šlais Karel 
Published: December 2009

AbstractIn virological practice, the pre‐concentration, purification and subsequent determination of the purity and concentration of the viruses from the cultural medium and/or from the real sample are required. The conventional techniques used today are equipment demanding, time‐consuming and laborious. In this study, the CIEF of influenza viruses with UV detection has been developed and subsequently used to test the purification of the virus from the biological samples. The equine and swine influenza viruses present in infected allantoic fluid of specific pathogen free embryonated chicken eggs were precipitated by using PEG 6000 and sodium chloride. The precipitated viruses were centrifuged at 14 000×g, and the impurities of different densities were removed by using the sucrose gradients. The efficiency of the virus purification technique was examined by the CIEF and compared to the results of real‐time PCR. The pIs of both influenza viruses were determined. Simultaneously, the CIEF was found to be a suitable method for the rapid testing of the efficiency of the virus purification.
CE‐ESI‐TOF/MS for human growth hormone analysis
Authors: Staub Aline , Giraud Sylvain , Saugy Martial , Rudaz Serge , Veuthey Jean‐Luc , Schappler Julie 
Published: December 2009

AbstractCE is a powerful analytical tool used to separate intact biomolecules such as proteins. The coupling of CE with TOF/MS produces a very promising method that can be used to detect and identify proteins in different matrices. This paper describes an efficient, rapid, and simple CE‐ESI‐TOF/MS procedure for the analysis of endogenous human growth hormone and recombinant human growth hormone without sample preparation. Operational factors were optimized using an experimental design, and the method was successfully applied to distinguish human growth hormone and recombinant human growth hormone in unknown samples.
Study on enantiomeric separation of basic drugs by NACE in methanol‐based medium using erythromycin lactobionate as a chiral selector
Authors: Chen Bin , Du Yingxiang , Wang Hao 
Published: December 2009

AbstractA wide variety of chiral selectors have been employed in CZE, and among them macrocyclic antibiotics including glycopeptides, ansamycins, aminoglycosides and polypeptides exhibited prominent enantioselective properties toward abundant racemic compounds. Compared with CZE, the use of macrocyclic antibiotics as chiral selectors in NACE has not been reported previously. In this study, an approach to the enantioseparation of basic drugs by means of NACE with erythromycin lactobionate (EL) belonging to the group of macrolide antibiotics has been investigated. Especially different from the above four classes of antibiotics, there are no reports concerned with the use of macrolides which belong to macrocyclic antibiotics as chiral selectors in CE. In this work EL is first used as a chiral selector in NACE for the enantiomeric separations of two racemic basic drugs that possess high separability consisting of propranolol and duloxetine. Furthermore, EL possesses advantages such as high solubility and low viscosity in the solvent and very weak UV absorption. The chiral separations were achieved using Tris‐boric acid as the BGE and methanol as the organic medium. In the course of this work we observed that both migration time and enantioseparation were influenced by several parameters such as the pH and composition of the BGE, EL concentration, capillary temperature and applied voltage. Consequently, these parameters were systematically optimized in order to obtain the optimum enantioseparations.
Ghrelin–liposome interactions: Characterization of liposomal formulations of an acylated 28‐amino acid peptide using CE
Authors: Østergaard Jesper , Moeller Eva H. 
Published: December 2009

AbstractGhrelin is a pharmacologically interesting peptide hormone due to its effects on appetite and metabolism. The cationic, octanoylated 28 amino acid peptide has a short biological half‐life; thus, prolonged release formulations are of interest. Acylated peptides have been suggested to bind to or be incorporated into liposomes. Formulations based on neutral dipalmitoylphosphatidylcholine (DPPC) liposomes and phosphatidylcholine:cholesterol (70:30 mol%) liposomes, and negatively charged dipalmitoylphosphatidylcholine:dipalmitoylphosphatidylserine (DPPC:DPPS) (70:30 mol%) liposomes (2 mM total lipid concentration) were characterized using ACE. Pre‐equilibrium CZE and frontal analysis CE methods circumventing capillary wall adsorption of the peptide and the liposomes and suitable for characterizing ghrelin–liposome interactions were developed. The cationic peptide exhibited low affinity (<10% bound) for DPPC and phosphatidylcholine:cholesterol (70:30 mol%) liposomes whereas electrostatic interactions caused a higher affinity for DPPC:DPPS (70:30 mol%) liposomes. Studies on desacyl ghrelin instead of ghrelin demonstrated the significance of the n‐octanoyl side chain as an affinity providing moiety towards DPPC:DPPS liposomes (48 and 73% bound peptide, respectively). CE experiments showed that the binding was characterized by rapid dissociation kinetics.
Corrosion of phosphate‐enriched titanium oxide surface dental implants (TiUnite®) under in vitro inflammatory and hyperglycemic conditions
Authors: Messer Regina L. W. , Seta Francesca , Mickalonis John , Brown Yolanda , Lewis Jill B. , Wataha John C. 
Published: December 2009

AbstractEndosseous dental implants use is increasing in patients with systemic conditions that compromise wound healing. Manufacturers recently have redesigned implants to ensure more reliable and faster osseointegration. One design strategy has been to create a porous phosphate‐enriched titanium oxide (TiUnite®) surface to increase surface area and enhance interactions with bone. In the current study, the corrosion properties of TiUnite® implants were studied in cultures of monocytic cells and solutions simulating inflammatory and hyperglycemic conditions. Furthermore, to investigate whether placement into bone causes enough mechanical damage to alter implant corrosion properties, the enhanced surface implants as well as machined titanium implants were placed into human cadaver mandibular bone, the bone removed, and the corrosion properties measured. Implant corrosion behavior was characterized by open circuit potentials, linear polarization resistance, and electrical impedance spectroscopy. In selected samples, THP1 cells were activated with lipopolysaccharide prior to implant exposure to simulate an inflammatory environment. No significant differences in corrosion potentials were measured between the TiUnite® implants and the machined titanium implants in previous studies. TiUnite® implants exhibited lower corrosion rates in all simulated conditions than observed in PBS, and EIS measurements revealed two time constants which shifted with protein‐containing electrolytes. In addition, the TiUnite® implants displayed a significantly lower corrosion rate than the machined titanium implants after placement into bone. The current study suggests that the corrosion risk of the enhanced oxide implant is lower than its machined surface titanium implant counterpart under simulated conditions of inflammation, elevated dextrose concentrations, and after implantation into bone. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Fibrillogenesis in continuously spun synthetic collagen fiber
Authors: Caves Jeffrey M. , Kumar Vivek A. , Wen Jing , Cui Wanxing , Martinez Adam , Apkarian Robert , Coats Julie E. , Berland Keith , Chaikof Elliot L. 
Published: December 2009

AbstractThe universal structural role of collagen fiber networks has motivated the development of collagen gels, films, coatings, injectables, and other formulations. However, reported synthetic collagen fiber fabrication schemes have either culminated in short, discontinuous fiber segments at unsuitably low production rates, or have incompletely replicated the internal fibrillar structure that dictates fiber mechanical and biological properties. We report a continuous extrusion system with an off‐line phosphate buffer incubation step for the manufacture of synthetic collagen fiber. Fiber with a cross‐section of 53± 14 by 21 ± 3 μm and an ultimate tensile strength of 94 ± 19 MPa was continuously produced at 60 m/hr from an ultrafiltered monomeric collagen solution. The effect of collagen solution concentration, flow rate, and spinneret size on fiber size was investigated. The fiber was further characterized by microdifferential scanning calorimetry, transmission electron microscopy (TEM), second harmonic generation (SHG) analysis, and in a subcutaneous murine implant model. Calorimetry demonstrated stabilization of the collagen triple helical structure, while TEM and SHG revealed a dense, axially aligned D‐periodic fibril structure throughout the fiber cross‐section. Implantation of glutaraldehyde crosslinked and noncrosslinked fiber in the subcutaneous tissue of mice demonstrated limited inflammatory response and biodegradation after a 6‐week implant period. © 2009 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2010
Mechanism of diepoxybutane‐induced p53 regulation in human cells
Authors: Yadavilli Sridevi , Chen Zhenping , Albrecht Thomas , Muganda Perpetua M. 
Published: December 2009

AbstractDiepoxybutane (DEB) is the most potent active metabolite of the environmental chemical 1,3‐butadiene (BD). BD is a known mutagen and human carcinogen and possesses multisystems organ toxicity. We previously reported the elevation of p53 in human TK6 lymphoblasts undergoing DEB‐induced apoptosis. In this study, we have characterized the DEB‐induced p53 accumulation and investigated the mechanisms by which DEB regulates this p53 accumulation. The elevation of p53 levels in DEB‐exposed TK6 lymphoblasts and human embryonic lung (HEL) human fibroblasts was found to be largely due to the stabilization of the p53 protein. DEB increased the acetylation of p53 at lys‐382, dramatically reduced complex formation between p53 and its regulator protein mdm2 and induced the phosphorylation of p53 at serines 15, 20, 37, 46, and 392 in human lymphoblasts. A dramatic increase in phosphorylation of p53 at serine 15 in correlation to total p53 levels was observed in DEB‐exposed Ataxia Telangiectasia Mutated (ATM) proficient human lymphoblasts as compared to DEB‐exposed ATM‐deficient human lymphoblasts; this implicates the ATM kinase in the elevation of p53 levels in DEB‐exposed cells. Collectively, these findings explain for the first time the mechanism by which p53 accumulates in DEB‐exposed cells and contributes to the understanding of the molecular toxicity of DEB and BD. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:373–386, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20300
Oncogene expression profiles in K6/ODC mouse skin and papillomas following a chronic exposure to monomethylarsonous acid
Authors: Delker Don A. , Geter David R. , Roop Barbara C. , Ward William O. , Ahlborn Gene J. , Allen James W. , Nelson Gail M. , Ouyang Ming , Welsh William , Chen Yan , O'Brien Thomas , Kitchin Kirk T. 
Published: December 2009

AbstractWe have previously observed that a chronic drinking water exposure to monomethylarsonous acid [MMA(III)], a cellular metabolite of inorganic arsenic, increases tumor frequency in the skin of keratin VI/ornithine decarboxylase (K6/ODC) transgenic mice. To characterize gene expression profiles predictive of MMA(III) exposure and mode of action of carcinogenesis, skin and papilloma RNA was isolated from K6/ODC mice administered 0, 10, 50, and 100 ppm MMA(III) in their drinking water for 26 weeks. Following RNA processing, the resulting cRNA samples were hybridized to Affymetrix Mouse Genome 430A 2.0 GeneChips®. Micoarray data were normalized using MAS 5.0 software, and statistically significant genes were determined using a regularized t‐test. Significant changes in bZIP transcription factors, MAP kinase signaling, chromatin remodeling, and lipid metabolism gene transcripts were observed following MMA(III) exposure as determined using the Database for Annotation, Visualization and Integrated Discovery 2.1 (DAVID) (Dennis et al., Genome Biol 2003;4(5):P3). MMA(III) also caused dose‐dependent changes in multiple Rho guanine nucleotide triphosphatase (GTPase) and cell cycle related genes as determined by linear regression analyses. Observed increases in transcript abundance of Fosl1, Myc, and Rac1 oncogenes in mouse skin support previous reports on the inducibility of these oncogenes in response to arsenic and support the relevance of these genomic changes in skin tumor induction in the K6/ODC mouse model. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:406–418, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20304
Sex‐specific effects of gestational and lactational coexposure to lead and cadmium on hepatic phase I and phase II xenobiotic/steroid‐metabolizing enzymes and antioxidant status
Authors: Pillai Prakash , Patel Ritesh , Pandya Chirayu , Gupta Sarita 
Published: December 2009

AbstractLiver has evolved complex enzymatic mechanisms to detoxify a wide array of xenobiotic substances, ranging from dietary components to environmental toxins to pharmaceuticals. Activities of many steroid‐metabolizing enzymes in adult rat liver microsomes are sexually differentiated. Toxic effects of lead and cadmium on hepatic tissue have been well established in our earlier studies. We thus monitored the effects of gestational and lactational coexposure to lead and cadmium on hepatic phase I and phase II xenobiotic‐ and steroid‐metabolizing enzyme activities in both male and female F1 generation postnatal day (PND) 56 rats. Adult pregnant female rats were treated subcutaneously [0.05 mg/(kg body wt. day)] with sodium acetate (control group), lead acetate, and cadmium acetate separately and in combination throughout the gestational and lactational period. Hepatic phase I xenobiotic‐metabolizing enzymes (NADPH‐ and NADH‐cytochrome c reductase) activities significantly decreased significantly in all the metal‐treated groups in both PND 56 male and female rats as compared with the control group. Hepatic phase II enzymes (uridine diphosphate‐glucuronosyl transferase, γ‐glutamyl transpeptidase, glutathione‐S‐transferase, 17‐β‐hydroxysteroid oxidoreductase) were also highly susceptible to all the metal‐treated groups. The observed alterations in the oxidative stress and biochemical parameters in the liver of F1 generation male and female rats resulted from an independent effect of lead and/or cadmium and also from their interaction. Results suggest that early developmental exposure to lead and cadmium both alone and in combination can suppress the hepatic xenobiotic‐metabolizing enzyme activities in the liver of F1 generation male and female rats in a sex‐dependent manner. © 2009 Wiley Periodicals, Inc. J Biochem Mol Toxicol 23:419–431, 2009; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/jbt.20305
Sonographic diagnosis of penile Mondor's disease associated with absence of a dorsal penile artery
Authors: Ozel Alper , Issayev Farkhad , Erturk Sukru Mehmet , Halefoglu Ahmet Mesrur , Karpat Zeki 
Published: December 2009

AbstractPenile Mondor's disease is an unusual condition, which is characterized by thrombosis in superficial dorsal penile vein. Here, we report the sonographic findings of this disease in a 35‐year‐old male along with the absence of right dorsal penile artery. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound 2010
Sonographic diagnosis of postpartum pseudoaneurysms of the uterine artery: A report of 2 cases
Authors: Marnela Katja , Saarelainen Sami , Palomäki Outi , Kirkinen Pertti 
Published: December 2009

AbstractTwo cases of post‐partum uterine artery pseudoaneurysm are described, 1 after normal vaginal delivery and the other after Caesarean section. Both cases were complicated by heavy bleeding and treated with catheter embolization. A turbulent arterial‐type velocity waveform with high peak velocity and forward end‐diastolic flow was registered in the feeding vessel. The peak blood flow velocity was high in both cases. The resistance index in the uterine artery was lower in the affected side of the uterus. Three‐dimensional angiosonography was used to calculate the volume of the lesion, demonstrate its shape, and identify the feeding vessel. © 2009 Wiley Periodicals, Inc. J Clin Ultrasound, 2010
Curcumin protects against hepatic and renal injuries mediated by inducible nitric oxide synthase during selenium‐induced toxicity in Wistar rats
Authors: Manikandan Ramar , Thiagarajan Raman , Beulaja Sivagnanam , Sudhandiran Ganapasam , Arumugam Munusamy 
Published: December 2009

AbstractThe aim of this study is to evaluate the effect of curcumin in protecting against selenium‐induced toxicity in liver and kidney of Wistar rats. Light microscopy evaluation of selenium alone administered rats showed liver to be infiltrated with mononuclear cells, vacuolation, necrosis, and pronounced degeneration. Control liver sections showed a regular morphology of parenchymal cells with intact hepatocytes and sinusoids. Kidney from selenium alone administered rats showed vacuolar degeneration changes in the epithelial cells, cellular proliferation with fibrosis, thickening of capillary walls, and glomerular tuft atrophy. Such changes were also observed in rats administered with selenium and curcumin simultaneously and rats administered first with selenium and then curcumin 24 h later. Interestingly, such degenerative changes observed in liver and kidney induced by selenium were not seen in rats that were administered with curcumin first and selenium 24 h later. This clearly suggests the protective nature of curcumin against selenium toxicity. To understand the probable mechanism of action of curcumin, we analyzed inducible nitric oxide synthase (iNOS) expression by immunohistochemistry, and the results showed an increased iNOS expression in selenium‐alone induced liver and kidney. Such high iNOS levels were inhibited in liver and kidney of rats pretreated with curcumin and then with selenium 24 h later. Based on the histological results, it can be concluded that curcumin functions as a protective agent against selenium‐induced toxicity in liver as well as kidney, and this action is probably by the regulatory role of curcumin on iNOS expression. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.
A reproducible technique for specific labeling of antigens using preformed fluorescent molecular IgG‐F(ab′)2 complexes from primary antibodies of the same species
Authors: Owen Gethin RH. , Häkkinen Lari , Wu Chuanyue , Larjava Hannu 
Published: December 2009

AbstractImmunolabeling two different antigens using the indirect approach with antibodies from the same species is not possible as secondary antibodies can bind to either primary target antibodies. In this study, we describe how preformed complexes of primary and secondary labeled antibodies can be used in such circumstances. In this situation, the first antigen is labeled using the conventional indirect method followed by incubation with the preformed primary–secondary antibody complex against the second antigen. To prevent unbound secondary antibody from binding the indirectly‐labeled antibodies, resulting in a false positive, we quenched excess secondary antibody with nonimmune murine serum from the species of the primary antibody. Before the formation of the preformed complex, the optimum dilution of both primary and secondary antibodies was determined. Once these concentrations were established, the concentration of nonimmune murine serum required to quench excess unbound secondary was determined. This step was accomplished by first incubating the sample with an antibody against an antigen known to be localized away from the antigen of interest, followed by the preformed complex. If specific staining was seen, other than that expected from the preformed complex, then the concentration of the serum was deemed insufficient for quenching, and increased accordingly. We demonstrate that this approach is successful in determining the optimum conditions for the preformation of ascites and purified monoclonal primary IgG with fluorescently conjugated F(ab′)2. Double immunolabelling of two focal adhesion antigens and two cytoskeletal proteins, with two murine primary antibodies, are presented as examples of the methodology. Microsc. Res. Tech., 2010. © 2009 Wiley‐Liss, Inc.