bluuebunny/crossref_metadata_2025 huggingface dataset:
Annealing Effects on Cathodoluminescence Properties of SiOx Films Deposited by Radio Frequency Sputtering
Authors: Shamekh Ahmed Mohamed Ahmed Abd El-Razek , Tokuda Norio , Inokuma Takao
Published: January 2011

The effects of high-temperature thermal annealing on cathodoluminescence (CL) spectra in SiO
x
(0.9 ≤x ≤1.87) films prepared by radio-frequency sputtering are investigated. The CL intensities for the as-deposited films are weak but they increase after thermal annealing at 900 and 1100 °C. One of features in the CL spectra for the films annealed at 1100 °C is a peak at a photon energy of ∼2.7 eV with an asymmetric tail on the lower energy side. In order to analyze the spectral features, optical transition energies are calculated for Si
n
clusters with n = 2–5, embedded in a SiO
x
matrix, by ab initio molecular orbital calculation. In addition, the probabilities of formation are statistically estimated for those Si clusters under the assumption of a chemically ordered random network for the SiO
x
network. The comparison of the experimental results with the calculated transition energies and the statistics of the Si clusters suggests that a contribution of the Si2 clusters to the CL spectra are dominant, whereas those of the Si
n
clusters with n > 3 are considerably small.
Three Dimensional Local Structure Analysis of ZnSnAs2:Mn by X-ray Fluorescence Holography
Authors: Hayashi Kouichi , Uchitomi Naotaka , Asubar Joel T. , Happo Naohisa , Hu Wen , Hosokawa Shinya , Suzuki Motohiro
Published: January 2011

X-ray fluorescence holographic study on a room-temperature ferromagnetic semiconductor film of ZnSnAs2:Mn was performed using a strong X-ray beam of third generation synchrotron radiation of SPring-8. The real space reconstructions of the environments around Mn atoms were successfully visualized from the observed holograms despite the very small amount of Mn atoms. The reconstructions revealed that the Mn atoms occupy the cation (Zn or Sn) site.
Effects of Pr Substitution on Electrical Properties of Bi(Fe0.95Mn0.05)O3 Thin Films
Authors: Wen Zheng , Wang Zhu , Chen Hengzhi , Shen Xuan , Li Xuefei , Wu Di , Yang Bin , Li Aidong
Published: January 2011

The effects of Pr3+ substitution on electrical properties of Bi(Fe0.95Mn0.05)O3 (BFMO) thin films are investigated. The leakage current densities of BFMO films can be significantly suppressed by Pr3+ substitution. Dielectric analysis reveals that dielectric constants of the films increase with increasing Pr3+ content. Reduced loss tangents are obtained in Pr3+-substituted BFMO films. Ferroelectric measurements demonstrate that Pr3+ substitution is helpful for lowering the coercive fields of films. In addition, a double hysteresis loop is observed in the BFMO film with 25% Bi3+ substituted by Pr3+. This may be ascribed to the existence of the defect-complexes.
Effects of Interface Nitride Layer on Electrical Characteristics of SiO2/Nitride/SiC Metal–Insulator–Semiconductor Diode
Authors: Yamakami Tomohiko , Suzuki Shinichiro , Henmi Mitsunori , Murata Yusuke , Hayashibe Rinpei , Kamimura Kiichi
Published: January 2011

A nitride layer was formed on a SiC surface by direct nitridation in NH3 or N2. The surface was characterized by X-ray photoelectron spectroscopy (XPS). The thickness of the nitride layer was estimated to be less than 2 nm. The metal–insulator–semiconductor (MIS) Schottky diode was formed on SiC using the nitride layer as the interface layer to estimate the interface state density between the nitride layer and the SiC substrate from the diode factor n. The interface state density was on the order of 1011–1012 eV-1·cm-2 at 0.3 eV below the conduction band edge. A SiO2 film was deposited on the nitridation layer to form an MIS diode. The interface state density of the SiO2/nitride/SiC sample was lower than that of the MIS Schottoky diode.
Scintillation Characteristic of In,Ga-Doped ZnO Thin Films with Different Dopant Concentrations
Authors: Fujimoto Yutaka , Yanagida Takayuki , Sekiwa Hideyuki , Yokota Yuui , Chani Valery , Yoshikawa Akira
Published: January 2011

The present study describes the first detailed evaluation of the rise and the decay time of scintillation phenomenon in In3+- and Ga3+-doped ZnO thin films with different dopant concentrations. In3+-(25, 55, and 141 ppm) and Ga3+-(33, 67, 333, and 1374 ppm) doped ZnO films were grown by the Liquid Phase Epitaxy (LPE) method. The characterization was performed using the pulse X-ray equipped streak camera system. Both the rise and the decay times were shortened considerably with increasing content of In3+ and Ga3+ in the films. However, the scintillation light yield under 241Am α-ray excitation reduced when concentration of In3+ and Ga3+ in the ZnO films was high.
Effect of 2-Propanol Concentration in Electrolyte Solution on Polypyrrole Actuator Performance
Authors: Hoshino Daiki , Morita Tsuyoshi , Chida Yutaka , Duan Zongfan , Ogihara Shou , Suzuki Yutaro , Nishioka Yasushiro
Published: January 2011

Organic soft linear actuators made of conducting polymers such as polypyrrole (PPy) films are of special interest for application in microelectromechanical systems (MEMS) because they generate large electrochemomechanical stress and strain. In this work, a PPy actuator was fabricated by galvanostatic electropolymerization. The electrochemical deformation behaviors of the PPy actuator were investigated in aqueous solutions of an electrolyte, lithium bis(trifluoromethanesulphonyl)imide (LiTFSI), containing different concentrations of 2-propanol. Marked improvement of the electrochemical strain from 3 to 12% was achieved when the actuator was driven by a potential between -1 and 1 V in the LiTFSI electrolyte containing 20 to 40% of 2-propanol under a load stress of 0.3 MPa. Possible mechanisms for these behaviors were discussed.
Interpretations of the Critical Indentation Depths in Soft Coatings on Hard Substrates from a Morphological Analysis on Nanocontact Impressions
Authors: Lee Yun-Hee , Kim Yongil , Ryu Kwon Sang , Nahm Seung Hoon , Yoon Ki-Bong
Published: January 2011

When a nanoindentation is carried out on a coating–substrate system, the resulting deformation can be influenced by not only the coating but also the substrate. In order to measure the coating-only contact properties, many works have been done to extract the critical indentation depth. In this study, we proposed a morphological parameter to determine the critical indentation depth by materializing interfacial constraints. From nanoindents were formed on 1.2-µm-thick Cu and Au coatings, several morphological parameters were analyzed such as remnant indentation volume, impression apex angle and apex bluntness. The critical relative depths of the Cu and Au coatings were, respectively, as 0.25 and 0.16 consistent with the results from the hardness and volumetric approach. In addition, the apex angle approach can explain the discrepancy between both hardness and volumetric approach because the new approach traces the ratio of superficial edge recovery and depth-directional shrinkage inside of an impression.
One-Step Liquid-Phase Synthesis of Carbon Nanotubes with Catalyst Precursors of Organometallic Complexes
Authors: Yamagiwa Kiyofumi , Kikitsu Tomoka , Yamashita Shunsuke , Kuwano Jun
Published: January 2011

This paper describes a simple, low cost one-step liquid-phase process for the synthesis of highly aligned carbon nanotube (CNT) arrays (HACNTAs). Highly pure HACNTAs were grown on a stainless steel substrate by resistance-heating in methanol solution containing one of the organometallic complex catalyst precursors, ferrocene Fe(C5H5)2 and iron pentacarbonyl Fe(CO)5. Effects of the catalyst precursors on the formation and morphologies of HACNTAs were examined. A small amount of non-aligned multi-walled CNTs (MWCNTs) were grown from 1 mM Fe(C5H5)2 methanol solution. Highly pure HACNTAs composed of MWCNTs were readily grown from 10 and 40 mM Fe(C5H5)2 methanol solutions by this one-step liquid-phase process. From the Fe(CO)5 methanol solution, HACNTAs were prepared even at a very low Fe(CO)5 concentration of 0.01 mM, which was about 1/1000 lower than that of Fe(C5H5)2. The optimal low concentration is attributed to the low decomposition temperature of Fe(CO)5.
Multi-Excitation-Laser Raman Analysis of Chirality-Controlled Single-Walled Carbon Nanotubes with Free Electron Laser Irradiation during Growth
Authors: Sakai Keijiro , Takeshita Hiroaki , Kaneki Kunihide , Yajima Hirofumi , Iwata Nobuyuki , Yamamoto Hiroshi
Published: January 2011

Single-walled carbon nanotubes (SWNTs) were fabricated by chemical vapor deposition using alcohol as a feeding gas of carbon. From the results of Raman spectroscopy with four kinds of exciting laser and consideration of chirality using the Kataura plot and chirality map, we found that the SWNTs grew with sizes from 0.92 to 1.41 nm in diameter, the possible chirality of which was 30. Metallic and semiconducting SWNTs grew. However, when irradiating 800 nm free-electron laser (FEL) during growth, the SWNTs of 1.1 nm diameter grew with a reduced possible chirality of 5, the electric property of which could be semiconducting. We revealed that the irradiation of FEL was effective to control the chirality of SWNTs to achieve ultrahigh-dense field effect devices.
Characterization of ZnO Nanostructures Synthesized through a Thermal Oxidation of Zn–C Mixture in Air
Authors: Lee Geun-Hyoung
Published: January 2011

Tetrapod-shaped ZnO crystals were synthesized via a simple oxidation process of Zn–C mixture in air at atmospheric pressure. The influence of carbon on the morphology and optical properties of the ZnO crystals was investigated. The ZnO crystals were characterized with an X-ray diffractometer (XRD), a scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR) and a cathodoluminescence (CL) spectroscopy. With increasing the carbon content in Zn source material, the size of ZnO tetrapods increased significantly. However, tetrapod-shaped ZnO crystals were not found from Zn–C mixture with a weight ratio of 1:1, indicating that carbon had an effect on the morphology of ZnO crystals as well as the size of tetrapods. CL spectra of the ZnO crystals exhibited a strong ultraviolet (UV) emission peak at 380 nm and a weak green emission peak at 510 nm. As the carbon content increased, the intensity of UV emission decreased and the green emission increased.
Various Shapes of ZnO and CdO Nanostructures Grown by Atmospheric-Pressure Chemical Vapor Deposition
Authors: Terasako Tomoaki , Fujiwara Tetsuro , Yagi Masakazu , Shirakata Sho
Published: January 2011

Various shapes of ZnO and CdO nanostructures were successfully grown ona- andc-plane sapphire substrates coated with Au nanocolloidal solution by atmospheric-pressure chemical vapor deposition methods under a simultaneous source supply of metal powder (Zn or Cd) and H2O. The ZnO and CdO nanorods (NRs) grown at higher substrate temperatures (TSs) exhibited tapered shapes, resulting from the competition between the axial growth due to the vapor–liquid–solid (VLS) mechanism and the radial growth due to the vapor–solid (VS) mechanism. The alternate source supply of Zn and H2O was found to be effective for suppressing the tapering of ZnO NRs. The appearance of the Y- and T-shaped nanotrees of CdO may be due to the splitting and migration of catalytic particles during the growth process. These results suggest that both the source supply sequence and the substrate temperature are important factors for the shape design of oxide nanostructures.
Estrogen receptor-β signaling modulates epithelial barrier function
Authors: Looijer-van Langen Mirjam , Hotte Naomi , Dieleman Levinus A. , Albert Eric , Mulder Chris , Madsen Karen L.
Published: January 2011

Impaired epithelial barrier function and estrogens are recognized as factors influencing inflammatory bowel disease (IBD) pathology and disease course. Estrogen receptor-β (ERβ) is the most abundant estrogen receptor in the colon and a complete absence of ERβ expression is associated with disrupted tight-junction formation and abnormal colonic architecture. The aim of this study was to determine whether ERβ signaling has a role in the maintenance of epithelial permeability in the colon. ERβ mRNA levels and colonic permeability were assessed in IL-10-deficient mice and HLA-B27 rats by RT-PCR and Ussing chambers. ERβ expression and monolayer resistance were measured in HT-29 and T84 colonic epithelial monolayers by RT-PCR and electric cell-substrate impedance sensing. The effect of 17β-estradiol and an estrogen agonist [diarylpropionitrile (DPN)] and antagonist (ICI 182780) on epithelial resistance in T84 cells was measured. Expression of ERβ and proinflammatory cytokines was investigated in colonic biopsies from IBD patients. Levels of ERβ mRNA were decreased, whereas colonic permeability was increased, in IL-10-deficient mice and HLA-B27 transgenic rats prior to the onset of colitis. T84 cells demonstrated higher resistance and increased levels of ERβ mRNA compared with HT-29 cells. 17β-estradiol and DPN induced increased epithelial resistance in T84 cells, whereas an ERβ blocker prevented the increased resistance. Decreased ERβ mRNA levels were observed in colonic biopsies from IBD patients. This study suggests a potential role for ERβ signaling in the modulation of epithelial permeability and demonstrates reduced ERβ mRNA in animal models of colitis and colon of patients with inflammatory bowel disease.
NHE2X3 DKO mice exhibit gender-specific NHE8 compensation
Authors: Xu Hua , Li Jing , Chen Rongji , Zhang Bo , Wang Chunhui , King Nolan , Chen Huacong , Ghishan Fayez K.
Published: January 2011

NHE8, the newest member of the sodium/hydrogen exchanger family, is expressed in the epithelial cells of the intestine and the kidney. Intestinal expression of NHE8 is significantly higher than that of NHE2 and NHE3 at a young age, suggesting that NHE8 is an important player for intestinal sodium absorption during early development. The current study was designed to explore if NHE8 plays a compensatory role for the loss of NHE2 and NHE3 function in NHE2X3 double-knockout (NHE2X3 DKO) mice. We further explored the regulatory mechanism(s) responsible for the change in NHE8 expression in NHE2X3 DKO mice. We found that >95% of NHE2X3 DKO mice survived through weanling. However, only 60% of male NHE2X3 DKO mice and 88% of female NHE2X3 DKO mice survived to 6 wk of life. We also found that the expression of NHE8 in wild-type female mice was higher compared with wild-type male mice after puberty. In NHE2X3 KDO mice, NHE8 expression was increased in females but not in males. Using Caco-2 cells as a model of the small intestine, we showed that testosterone inhibited endogenous NHE8 expression by reducing NHE8 mRNA synthesis, whereas estrogen had no effect on NHE8 expression. Thus our data show for the first time that intestinal NHE8 has a compensatory role in NHE2X3 DKO mice and this regulation is gender-dependent.
IMP-1 Displays Cross-Talk with K-Ras and Modulates Colon Cancer Cell Survival through the Novel Proapoptotic Protein CYFIP2
Authors: Mongroo Perry S. , Noubissi Felicite K. , Cuatrecasas Miriam , Kalabis Jiri , King Catrina E. , Johnstone Cameron N. , Bowser Mark J. , Castells Antoni , Spiegelman Vladimir S. , Rustgi Anil K.
Published: January 2011

Insulin-like growth factor 2 mRNA-binding protein-1 (IMP-1) is an oncofetal protein that binds directly to and stabilizes oncogenic c-Myc and regulates, in turn, its posttranscriptional expression and translation. In contrast to normal adult tissue, IMP-1 is reexpressed and/or overexpressed in human cancers. We show that knockdown of c-Myc in human colon cancer cell lines increases the expression of mature let-7 miRNA family members and downregulates several of its mRNA targets: IMP-1, Cdc34, and K-Ras. We further show that loss of IMP-1 inhibits Cdc34, Lin-28B, and K-Ras, suppresses SW-480 cell proliferation and anchorage-independent growth, and promotes caspase- and lamin-mediated cell death. We also found that IMP-1 binds to the coding region and 3′UTR of K-Ras mRNA. RNA microarray profiling and validation by reverse transcription PCR reveals that the p53-inducible proapoptotic protein CYFIP2 is upregulated in IMP-1 knockdown SW480 cells, a novel finding. We also show that overexpression of IMP-1 increases c-Myc and K-Ras expression and LIM2405 cell proliferation. Furthermore, we show that loss of IMP-1 induces Caspase-3- and PARP-mediated apoptosis, and inhibits K-Ras expression in SW480 cells, which is rescued by CYFIP2 knockdown. Importantly, analysis of 228 patients with colon cancers reveals that IMP-1 is significantly upregulated in differentiated colon tumors (P ≤ 0.0001) and correlates with K-Ras expression (r = 0.35, P ≤ 0.0001) relative to adjacent normal mucosa. These findings indicate that IMP-1, interrelated with c-Myc, acts upstream of K-Ras to promote survival through a novel mechanism that may be important in colon cancer pathogenesis. Cancer Res; 71(6); 2172–82. ©2011 AACR.
Natural Killer Cells Efficiently Reject Lymphoma Silenced for the Endoplasmic Reticulum Aminopeptidase Associated with Antigen Processing
Authors: Cifaldi Loredana , Lo Monaco Elisa , Forloni Matteo , Giorda Ezio , Lorenzi Silvia , Petrini Stefania , Tremante Elisa , Pende Daniela , Locatelli Franco , Giacomini Patrizio , Fruci Doriana
Published: January 2011

The endoplasmic reticulum aminopeptidase ERAAP is involved in the final trimming of peptides for presentation by MHC class I (MHC-I) molecules. Herein, we show that ERAAP silencing results in MHC-I peptide-loading defects eliciting rejection of the murine T-cell lymphoma RMA in syngeneic mice. Although CD4 and CD8 T cells are also involved, rejection is mainly due to an immediate natural killer (NK) cell response and depends on the MHC-I-peptide repertoire because replacement of endogenous peptides with correctly trimmed, high-affinity peptides is sufficient to restore an NK-protective effect of MHC-I molecules through the Ly49C/I NK inhibitory receptors. At the crossroad between innate and adaptive immunity, ERAAP is therefore unique in its two-tiered ability to control tumor immunogenicity. Because a large fraction of human tumors express high levels of the homologous ERAP1 and/or ERAP2, the present findings highlight a convenient, novel target for cancer immunotherapy. Cancer Res; 71(5); 1597–606. ©2011 AACR.
Synergistic Effects of Foretinib with HER-Targeted Agents in MET and HER1- or HER2-Coactivated Tumor Cells
Authors: Liu Li , Shi Hong , Liu Yuan , Anderson Amber , Peterson John , Greger James , Martin Anne-Marie , Gilmer Tona M.
Published: January 2011

The HER and MET receptor tyrosine kinases (RTK) are coactivated in a subset of human tumors. This study characterizes MET and HER expression and signaling in a panel of human tumor cell lines and the differential susceptibility of these cell lines to single agents or combinations of foretinib, a multikinase MET inhibitor, with HER-targeted agents, erlotinib or lapatinib. Most MET-amplified tumor lines without HER1 or HER2 amplification are sensitive to foretinib, whereas MET-amplified lines with HER1 or HER2 amplification are more sensitive to the combination of foretinib with lapatinib or erlotinib. Interestingly, MET-overexpressing tumor cell lines with HER1 or HER2 amplification also exhibited reduced sensitivity to lapatinib or erlotinib in the presence of hepatocyte growth factor (HGF), indicating MET activation can decrease the effectiveness of HER1/2 inhibitors in some cell lines. Consistent with this observation, the effect of HGF on lapatinib or erlotinib sensitivity in these cells was reversed by foretinib, other MET inhibitors, or siRNA to MET. Western blot analyses showed that combining foretinib with erlotinib or lapatinib effectively decreased the phosphorylation of MET, HER1, HER2, HER3, AKT, and ERK in these cells. Furthermore, HER2-positive advanced or metastatic breast cancer patients treated with lapatinib who had higher tumor MET expression showed shorter progression-free survival (19.29 weeks in MET-high patients vs. 28.14 weeks in MET-low patients, P < 0.0225). These data suggest that combination therapy with foretinib and HER-targeted agents should be tested as a treatment option for HER1- or HER2-positive patients with MET-amplified or -overexpressing tumors. Mol Cancer Ther; 10(3); 518–30. ©2011 AACR.
Interactions of Tyrosine Kinase Inhibitors with Organic Cation Transporters and Multidrug and Toxic Compound Extrusion Proteins
Authors: Minematsu Tsuyoshi , Giacomini Kathleen M.
Published: January 2011

The drug–drug interaction (DDI) potential of tyrosine kinase inhibitors (TKI) as interacting drugs via transporter inhibition has not been fully assessed. Here, we estimated the half maximal inhibitory concentration (IC50) values for 8 small-molecule TKIs (imatinib, dasatinib, nilotinib, gefitinib, erlotinib, sunitinib, lapatinib, and sorafenib) on [14C]metformin transport by human organic cation transporters (OCT), OCT1, OCT2, and OCT3, and multidrug and toxic compound extrusion (MATE) proteins, MATE1 and MATE2-K, using human embryonic kidney cells stably expressing these transporters. We then compared the estimated IC50 values to the maximum clinical concentrations of unbound TKIs in plasma (unbound Cmax,sys,p). Results showed that imatinib, nilotinib, gefitinib, and erlotinib exerted selectively potent inhibitory effects, with unbound Cmax,sys,p/IC50 values ≥0.1, on MATE1, OCT3, MATE2-K, and OCT1, respectively. In comparison to the common form of OCT1, the OCT1 polymorphism, M420del, was more sensitive to drug inhibition by erlotinib. Major metabolites of several TKIs showed IC50 values similar to those for unchanged TKIs. Taken together, these findings suggest the potential of clinical transporter-mediated DDIs between specific TKIs and OCTs and MATEs, which may affect the disposition, efficacy, and toxicity of metformin and other drugs that are substrates of these transporters. The study provides the basis for further clinical DDI studies with TKIs. Mol Cancer Ther; 10(3); 531–9. ©2011 AACR.
Effect of Early or Delayed Administration of Warfarin with Heparin on Thrombosis in Pulmonary Thromboembolism
Authors: Ozlu Tevfik , Aycicek Olcay , Sonmez Mehmet , Bulbul Yilmaz , Omay Serdar Bedii , Oztuna Funda , Durmus Ahmet
Published: January 2011

Objective: The aim of this study was to investigate the effect of early or delayed warfarin administration with unfractionated heparin (UFH) on coagulation parameters in pulmonary thromboembolism (PTE). Patients and Methods: This study was performed between November 2006 and July 2007. Thirty-three patients with PTE were sequentially slotted to early (n = 16) and delayed (n = 17) warfarin treatment groups. In the early group, both UFH infusion and warfarin were started simultaneously and in the delayed group, warfarin was added (1–3 days later) based on when partial thromboplastin time reached the therapeutic level with UFH. The proteins C and S, D-dimer, hematocrit levels, and platelet counts for all patients were studied prior to treatment and 6, 24, and 48 h after warfarin treatment. In order to determine the overall effect of early and delayed warfarin treatment on clot formation, a thromboelastogram was performed simultaneously. Results: In both groups, a similar chronological decrease in protein C levels reaching maximum at 24 h with warfarin treatment was observed. However, intragroup or intergroup decreases in protein S levels were not different. On thromboelastogram, INTEM and EXTEM clotting times were significantly prolonged chronologically, but this prolongation was not different between groups. Conclusion: The suppressor effect of warfarin on proteins C and S in the early period of double anticoagulant treatment did not appear to aggravate the risk of thrombosis in patients with PTE in whom warfarin was started simultaneously with UFH.
Bixa orellana Leaves Extract Inhibits Bradykinin-Induced Inflammation through Suppression of Nitric Oxide Production
Authors: Yoke Keong Y. , Arifah A.K. , Sukardi S. , Roslida A.H. , Somchit M.N. , Zuraini A.
Published: January 2011

Objective: The present study was conducted to assess the anti-inflammatory effect of a crude aqueous extract of Bixa orellana leaves (AEBO) and to examine the possible involvement of nitric oxide (NO) in its anti-inflammatory mechanism. Materials and Methods: The air-dried, powdered leaves were soaked in distilled water (1:20 w/v) at 50°C for 24 h and the supernatant obtained was freeze-dried (yield 8.5% w/w). The dosage was recorded as the mass of extract per kg b.w. of rats in all inflammatory assays (bradykinin-induced paw edema, peritoneal vascular permeability and NO assay). Results: Pretreatment with AEBO for 4 consecutive days exhibited significant inhibitory activity against inflammatory models, the bradykinin-induced hind paw edema model and bradykinin-induced increased peritoneal vascular permeability at both doses in dose-dependent manner. In addition, AEBO was also found to significantly suppress the production of NO at doses of 50 and 150 mg/kg. Conclusion: This study provides scientific data to support the traditional use of B. orellana leaves in treating inflammation. Results from this study suggest that AEBO exerts anti-inflammatory effects. Part of this anti-inflammatory effect may be associated with its antibradykinin activity and may be related to a reduction of the NO production.
Molecular Characterization and Epidemiology of Extended-Spectrum Beta-Lactamase-Producing Escherichia coli and Klebsiella pneumoniae Isolates in the United Arab Emirates
Authors: Alfaresi Mubarak Saif , Elkoush Abida A. , Alshehhi Hajar M. , Abdulsalam Adeel Islam
Published: January 2011

Objectives: The aim of this prospective study was to assess the extent of dissemination of extended-spectrum β-lactamase (ESBL)-producing Enterobacteriaceae at the hospital level in the United Arab Emirates (UAE). Materials and Methods:A total of 662 Escherichia coli and Klebsiellapneumoniae samples were collected from three UAE hospitals between January and December 2008. ESBL screening and confirmatory test for ESBL phenotype were conducted using the VITEK system. Molecular typing was performed using specific primers and then sequencing. Results: A total of 240 (36%) samples were identified as ESBL producers, including both E. coli (n = 150) and K. pneumoniae (n = 90). All of these isolates were resistant to cefazoline and cefotaxime, but remained susceptible to imipenem. Molecular analysis revealed that, of the 240 ESBL producers, 228 carried the ESBL bla genes. A majority of the strains 199 (87%) expressed the CTX-M-15 gene. The SHV-28 gene was detected in 29 (13%) of the strains. Conclusion: The present study highlighted the emergence and dissemination of CTX-M-15-producing E. coli and K. pneumoniae in the UAE. This is the first report of SHV-28-producing Enterobacteriaceae in the country.
p53 Protein Accumulation and Presence of Visceral Metastasis Are Independent Prognostic Factors for Survival in Patients with Metastatic Inflammatory Breast Carcinoma
Authors: Sezgin Canfeza , Gokmen Erhan , Kapkac Murat , Zekioglu Osman , Esassolak Mustafa , Karabulut Bulent , Sanli Ulus Ali , Uslu Ruchan
Published: January 2011

Objective: The aim of this study was to determine the markers of prognosis in metastatic inflammatory breast cancer (IBC). Subjects and Methods: The prognostic value of patients’ clinical characteristics and expression of c-erbB-2, p53, Ki-67, ER and PgR were assessed in the 45 patients with IBC who had developed distant metastasis. Immunohistochemical methods were used to detect the expression of c-erbB-2, p53, Ki-67, ER and PgR in surgical resection specimens of the patients’ primary tumor. Results: The median overall survival (OS) measured from the diagnosis of metastatic disease was 23 months. In the univariate analysis, p53 protein accumulation and the presence of visceral metastasis were predictive of poor survival (p = 0.01 and 0.003, respectively). In the multivariate analysis, accumulation of p53 protein and the presence of visceral metastasis correlated with OS (p = 0.02 and 0.008, respectively). Conclusion: In metastatic IBC, accumulation of p53 protein and presence of visceral metastasis are independent prognostic factors for OS. Established prognostic factors in non-IBC patients such as patient age, histologic grade, hormone receptor status and c-erbB-2 status did not have independent significance in IBC in this study.
Low-Molecular-Weight Heparin Successfully Used to Treat a Nephrotic Patient Complicated by Superior Mesenteric Vein Thrombosis and Portal Vein Thrombosis
Authors: Wang Yi-Chun , Chuang Feng-Rong , Lee Wen-Chin , Chen Te-Chuan , Ko Sheung-Fat , Wang I-Kuan , Lee Chih-Hsiung
Published: January 2011

Objectives: To report the success of treatment with low- molecular-weight heparins (LMWHs) in a case of nephrotic syndrome complicated by mesenteric vein thrombosis (MVT) and portal vein thrombosis (PVT). Clinical Presentation and Intervention: A 53-year-old man with nephrotic syndrome developed persistent mild abdominal pain for 3 days. Hepatic-portal venous system thrombosis of nephrotic syndrome was suspected due to new-onset superficial vein engorgement of the abdomen without liver cirrhosis. Abdominal computed tomography revealed MVT concomitant with PVT. He was successfully treated with LMWH without thrombolytic therapy. After discharge on day 9, he received continuous anticoagulation by LWMH on an outpatient basis at the nephrology clinic. Venous thromboembolic events or proteinuria did not recur within the 6-month follow-up. Conclusion: This report showed a case of MVT concomitant with PVT, a critical complication of nephrotic syndrome that was diagnosed in time and successfully treated with LMWH. A high index of clinical suspicion and timely management are crucial to tackle thrombotic complications in nephrotic syndrome.
Effect of Opium Dependency on Burn Healing in a Rat Model: An Experimental Study
Authors: Zeinalinejad Hamid , Ramezani Mohammad Arash , Shafiee Mohammad , Karvar Mohsen , Malekpour-Afshar Reza
Published: January 2011

Objective: This study aimed to investigate the effect of opium dependency on the healing of third-degree burns in rats. Material and Methods: Twenty-four rats were randomly divided to experimental and control groups. In the experimental group, opium was added to the drinking water for 21 days at increasing concentrations. The control group did not receive opium. To prove dependency on opium in the rats, naloxone was injected intraperitoneally. Full-thickness burn wounds were inflicted by applying an iron cuboid preheated to 94°C to the flank of all rats for 20 s. On day 14 after burn injury, full-thickness biopsies were taken. Blind histopathologic evaluation was performed to assess length and thickness of the re-epithelialization area, number of neutrophils, fibroblasts, mononuclear cells and new vessels, and percentage of tissue in repair (neutrophilic exudate, and granulation and fibrous tissue). Findings were analyzed using SPSS software. Results: The wound surface area was 95 ± 43.35 mm2 in the control group and 120.4 ± 50.12 mm2 in the experimental group (p = 0.224). The findings show that opium dependency has no significant effect on the healing of burn wounds in rats except for the number of monocytes on day 14 (p < 0.05). Conclusion: Morphine dependency does not seem to be as effective on third-degree burn healing.
99mTc Sulfur Colloid and 99mTc Mebrofenin Hepatobiliary Functional Liver Imaging in Normal and Diabetic Rats
Authors: Al-Saeedi Fatma , Loutfi Issa
Published: January 2011

Objectives: To use 99mTc sulfur colloid (99mTc-SC) and 99mTc mebrofenin (99mTc-BrIDA) to study liver function in normal and diabetic rats. Materials and Methods: Radionuclide imaging was performed on 2 groups of rats, using 99mTc-SC for one group and 99mTc-BrIDA for the other (20 rats per group) before and after induction of diabetes mellitus (DM) using streptozotocin administration (55 mg/kg i.p.). Dynamic acquisition was obtained for 1 h after the injection of 37 MBq of radiotracer. For the 99mTc-SC group, organ/tissue uptake was determined by drawing regions of interest (ROI) over the heart, liver, spleen and also the whole body (WB). The ratio of the ROI of each organ to the WB ROI was calculated. For 99mTc-BrIDA, ratios of cumulative count rates in liver, liver parenchyma, biliary tree and abdomen ROI to a WB ROI were also calculated. Statistical analysis was performed to compare the ratios of organ/tissue uptake to WB uptake before and after DM induction using the paired t test. Results:99mTc-SC uptake ratios (means ±SD) showed a lower liver-to-WB uptake ratio (0.75 ± 0.05) in the rats after DM induction compared to baseline (0.81 ± 0.06), while the cardiac blood pool showed higher uptake ratios in the rats after DM induction (p = 0.026). For 99mTc-BrIDA, there was no significant difference in radiotracer uptake ratios obtained from the rats before and after DM induction (p = 0.41). Conclusion: Using functional liver imaging, there was a statistically significant decrease in the liver phagocytic/reticuloendothelial system function after DM induction, as evidenced by decreased 99mTc-SC liver uptake and increased blood pool compared to prediabetes, while the hepatobiliary function remained unchanged after DM induction using 99mTc-BrIDA imaging.
Skin Manifestations in Diabetic Patients Attending a Diabetic Clinic in the Qassim Region, Saudi Arabia
Authors: Shahzad Muhammad , Al Robaee Ahmad , Al Shobaili Hani A. , Alzolibani Abdullateef A. , Al Marshood Abdullah A. , Al Moteri Barakat
Published: January 2011

Objective: To investigate the prevalence of skin manifestations in diabetic patients attending a diabetic clinic in the Qassim region, Saudi Arabia. Subjects and Methods: A prospective observational study was performed on 320 patients (174 males and 146 females) attending the diabetic clinic. A detailed dermatological examination was carried out by a consultant dermatologist and the cutaneous findings were recorded. Results: The overall prevalence of skin manifestations was 91.2%. Cutaneous lesions were seen in 12 patients (34.3%) of type 1 diabetes mellitus (DM) and 280 (98.2%) of type 2 diabetics. There was a statistically significant difference (p < 0.001) in skin manifestations between type 1 and type 2 DM patients. For those patients having diabetes of less than 5 years’ duration, the incidence of skin manifestations was 80.6%; for those having had diabetes for more than 5 years, the incidence was 98%. This difference was statistically significant (p < 0.001). The skin manifestations that had a statistically significant difference (p < 0.05) in prevalence between the 2 durational groups were gangrene, diabetic dermopathy, paresthesia, diabetic feet, diabetic bullae and fungal infections. Conclusion: Diabetics had a greater prevalence of skin manifestations in type 2 than type 1, and as the duration of diabetes increased, the likelihood of developing skin manifestations also increased. Early referral to the dermatologist may help to detect complications of the skin in diabetes at an early stage and may prevent disability caused by these complications.
Endothelial Progenitor Cells in Long-Standing Asymptomatic Type 1 Diabetic Patients with or without Diabetic Nephropathy
Authors: Reinhard Henrik , Jacobsen Peter Karl , Lajer Maria , Tarnow Lise , Astrup Anne Sofie , Kim Won Yong , Pedersen Nadja , Billestrup Nils , Mandrup-Poulsen Thomas , Parving Hans-Henrik , Rossing Peter
Published: January 2011

A decrease in the number and dysfunction of endothelial progenitor cells (EPC) may increase the risk for progression of cardiovascular disease (CVD) in type 1 diabetic patients with diabetic nephropathy (DN). Our aim was to evaluate EPC numbers in asymptomatic CVD type 1 diabetic patients with or without DN and to study the effect of CVD and medication on EPC numbers. Methods: We examined EPC numbers in 37 type 1 diabetic patients with DN and 35 type 1 diabetic patients with long-standing normoalbuminuria. Patients were without symptoms of CVD and the prevalence of CVD was previously shown to be very low. EPC number was assessed in in vitro cultures by fluorescent staining of attached cells. Results: There was no difference in EPC numbers between patients with DN (mean ± SD 120 ± 49 cells/field) and normoalbuminuria (108 ± 41 cells/field; p = 0.25). Furthermore, EPC number was not associated with CVD (p > 0.05). Conventional risk factors were significantly higher in patients with DN and they received more CVD-preventive treatment. All patients receiving simvastatin or calcium-channel blockers had higher numbers of EPC compared to patients not treated with these drugs. Conclusions: Asymptomatic patients with DN had EPC numbers similar to normoalbuminuric patients, which was related to aggressive CVD intervention therapy. This may have contributed to the low prevalence of CVD.
Quo Vadis 2010? – Carpe Diem: Challenges and Opportunities in Pediatric Traumatic Brain Injury
Authors: Kochanek Patrick M. , Bell Michael J. , Bayır Hülya
Published: January 2011

Traumatic brain injury (TBI) in infants and children remains a public health problem of enormous magnitude. It is a complex and heterogeneous condition that presents many diagnostic, therapeutic and prognostic challenges. A number of investigative teams are studying pediatric TBI both in experimental models and in clinical studies at the bedside. This review builds on work presented in a prior supplement to Developmental Neuroscience that was published in 2006, and addresses several active areas of research on this topic, including (1) the application of novel imaging methods, (2) the use of serum and/or CSF biomarkers of injury, (3) advances in neuromonitoring, (4) the development and testing of novel therapies, (5) developments in modeling pediatric TBI, (6) the consideration of a new approach to classification of pediatric TBI, and (7) assessing the potential impact of the development of pediatric and neonatal neurocritical care services on the management and outcome of pediatric TBI.
Eotaxin in Exhaled Breath Condensate of Allergic Asthma Patients with Exercise-Induced Bronchoconstriction
Authors: Zietkowski Z. , Skiepko R. , Tomasiak-Lozowska M.M. , Zietkowska E. , Bodzenta-Lukaszyk A.
Published: January 2011

Background: Eosinophils are the key inflammatory cells in asthma, and more and more evidence suggests their crucial role in exercise-induced bronchoconstriction (EIB). Eotaxin, as the most important chemotactic factor for eosinophils, plays an important role in the pathogenesis of asthma. Objectives: The aim of the study was to evaluate the changes in eotaxin levels in exhaled breath condensate (EBC) following intensive exercise in allergic asthmatics. Methods: The study was performed in a group of 27 asthmatics (17 with EIB, 13 without EIB) and 9 healthy volunteers. Changes induced by intensive exercise in the concentrations of eotaxin in EBC during the 24 h after an exercise test were assessed. The possible correlations of these measurements with the results of other tests commonly associated with eosinophilic airway inflammation were also determined. Results: In asthmatic patients with EIB, a statistically significant increase in eotaxin concentrations in EBC collected during the first 24 h after an exercise test – with maximal increase after 6 h – was revealed. A statistically significant correlation between the maximum increase in eotaxin concentrations in EBC after exercise, and an increase in either serum eosinophil cationic protein or FENO 24 h after exercise in the group of asthmatics with EIB, was observed. Conclusions: Our results confirm connections between EIB and airway eosinophilic inflammation. The increase of eotaxin in asthmatic airways, by promoting the migration and activation of eosinophils, may play an important role in upregulation and sustaining of the airway inflammation observed in EIB in asthmatic patients.
Cerebral Infarct in Patients with Bilateral High-Grade Internal Carotid Artery Stenosis: Analysis by Diffusion-Weighted Imaging
Authors: Hong Chien-Tai , Chan Hoi-Fong , Lee Siu-Pak , Jang Jeng-Shin
Published: January 2011

Background: Bilateral high-grade internal carotid artery (ICA) stenosis is critical for brain perfusion, and mechanisms of cerebral infarct induced by bilateral high-grade ICA stenosis can be investigated by the infarct patterns on diffusion-weighted imaging (DWI). Methods: From January 2006 to October 2010, we retrospectively enrolled 21 acute infarct patients with bilateral high-grade ICA stenosis. The infarct patterns were divided into territory, cortical border-zone and internal border-zone by DWI. Results: The milder ICA stenosis side had a lower risk of ischemic stroke (4 of 20). None of the 8 patients with bilateral severe ICA stenosis (70–99%) suffered ischemic stroke ipsilateral to the milder ICA stenosis side. No single infarct mechanism was prominent: 10 of 21 infarcts were cortical border-zone pattern, followed by internal border-zone (7 of 21) and territory. The difference in frequency of bilateral severe ICA stenosis between the three infarct mechanisms was not significant (p = 0.856). Conclusions: Cerebral infarcts occurred less frequently in the ipsilateral to milder ICA stenosis side, especially in bilateral severe ICA stenosis. The similar frequencies and hemodynamic status between the three infarct pattern groups indicated that both artery-to-artery emboli and being hemodynamically compromised contribute synergistically to bilateral ICA stenosis.
Modifications of the Innate Immune System in Atopic Dermatitis
Authors: Maintz Laura , Novak Natalija
Published: January 2011

Atopic dermatitis (AD) is a frequent chronic inflammatory skin disease which is often complicated by recurrent microbial superinfections. Genetically based modifications which might have an impact on the innate immune system, such as impairment of the skin barrier, modifications of pattern recognition receptors, deficiency of antimicrobial peptides, antiviral natural killer cells and plasmacytoid dendritic cells, facilitate the entry of allergens and infectious microbes into the skin, where they encounter immunocompetent cells. The micromilieu in the skin of AD patients further potentiates dysfunctions of the innate immune system, leading to a vicious circle promoting the disease. This article provides an overview of modifications of the innate immune system in AD.
Novel Role of Platelets in Mediating Inflammatory Responses and Ventricular Rupture or Remodeling Following Myocardial Infarction
Authors: Liu Yang , Gao Xiao-Ming , Fang Lu , Jennings Nicole L. , Su Yidan , Q Xu , Samson Andre L. , Kiriazis Helen , Wang Xin-Feng , Shan Leonard , Sturgeon Sharelle A. , Medcalf Robert L. , Jackson Shaun P. , Dart Anthony M. , Du Xiao-Jun
Published: January 2011

Objective—

The goal of this study was to investigate the role of platelets in systemic and cardiac inflammatory responses and the development of postinfarct ventricular complications, as well as the efficacy of antiplatelet interventions.

Methods and Results—

Using a mouse myocardial infarction (MI) model, we determined platelet accumulation and severity of inflammation within the infarcted myocardium by immunohistochemistry and biochemical assays, analyzed peripheral blood platelet-leukocyte conjugation using flow cytometry, and tested antiplatelet interventions, including thienopyridines and platelet depletion. Platelets accumulated within the infarcted region early post-MI and colocalized with inflammatory cells. MI evoked early increase in circulating platelet-leukocyte conjugation mediated by P-selectin/P-selectin glycoprotein ligand-1. Antiplatelet interventions inhibited platelet-leukocyte conjugation in peripheral blood, inflammatory infiltration, content of matrix metalloproteinases or plasminogen activation, and expression of inflammatory mediators in the infarcted myocardium (all
P
<0.05) and lowered rupture incidence (
P
<0.01). Clopidogrel therapy alleviated the extent of chronic ventricular dilatation by serial echocardiography.

Conclusion—

Platelets play a pivotal role in promoting systemic and cardiac inflammatory responses post-MI. Platelets accumulate within the infarcted myocardium, contributing to regional inflammation, ventricular remodeling, and rupture. Antiplatelet therapy reduces the severity of inflammation and risk of post-MI complications, demonstrating a previously unrecognized protective action.
Detection of Macrophages in Aortic Aneurysms by Nanoparticle Positron Emission Tomography–Computed Tomography
Authors: Nahrendorf Matthias , Keliher Edmund , Marinelli Brett , Leuschner Florian , Robbins Clinton S. , Gerszten Robert E. , Pittet Mikael J. , Swirski Filip K. , Weissleder Ralph
Published: January 2011

Objective—

Current management of aortic aneurysms (AAs) relies primarily on size criteria to determine whether invasive repair is indicated to preempt rupture. We hypothesized that emerging molecular imaging tools could be used to more sensitively gauge local inflammation. Because macrophages are key effector cells that destabilize the extracellular matrix in the arterial wall, it seemed likely that they would represent suitable imaging targets. We here aimed to develop and validate macrophage-targeted nanoparticles labeled with fluorine-18 (
18
F) for positron emission tomography–computed tomography (PET-CT) detection of inflammation in AAs.

Methods and Results—

Aneurysms were induced in apolipoprotein E
−/−
mice via systemic administration of angiotensin II. Mice were imaged using PET-CT and a monocyte/macrophage–targeted nanoparticle. AAs were detected by contrast-enhanced micro-CT and had a mean diameter of 1.85±0.08 mm, whereas normal aortas measured 1.07±0.03 (
P
<0.05). The in vivo PET signal was significantly higher in aneurysms (standard uptake value, 2.46±0.48) compared with wild-type aorta (0.82±0.05,
P
<0.05). Validation with scintillation counting, autoradiography, fluorescence, and immunoreactive histology and flow cytometry demonstrated that nanoparticles localized predominantly to monocytes and macrophages within the aneurysmatic wall.

Conclusion—

PET-CT imaging with
18
F-labeled nanoparticles allows quantitation of macrophage content in a mouse model of AA.
Platelet Protein Kinase C-θ Deficiency With Human RUNX1 Mutation
Authors: Jalagadugula Gauthami , Mao Guangfen , Kaur Gurpreet , Dhanasekaran Danny N. , Rao A. Koneti
Published: January 2011

Objective—

Mutations in the hematopoietic transcription factor RUNX1 cause thrombocytopenia and impaired platelet function. In a patient with a heterozygous mutation in RUNX1, we have described decreased platelet pleckstrin phosphorylation and protein kinase C-θ (PKC-θ, gene
PRKCQ
) associated with thrombocytopenia, impaired platelet aggregation, and dense granule secretion. Little is known regarding regulation of PKC-θ in megakaryocytes and platelets. We have addressed the hypothesis that
PRKCQ
is a direct transcriptional target of RUNX1.

Methods and Results—

In a chromatin immunoprecipitation assay using megakaryocytic cells, there was RUNX1 binding in vivo to
PRKCQ
promoter region −1225 to −1056 bp containing a RUNX1 consensus site ACCGCA at −1088 to −1069 bp; an electrophoretic mobility shift assay showed RUNX1 binding to the specific site. In RUNX1 overexpression studies, PKC-θ protein expression and promoter activity were enhanced; mutation of RUNX1 site showed decreased activity even with RUNX1 overexpression. Lastly,
PRKCQ
promoter activity and PKC-θ protein were decreased by short interfering RNA knockdown of RUNX1.

Conclusion—

Our results provide the first evidence that
PRKCQ
is regulated at the transcriptional level by RUNX1 in megakaryocytic cells and a mechanism for PKC-θ deficiency associated with RUNX1 haplodeficiency.