bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of Updated Interpretative Criteria for Categorizing
Klebsiella pneumoniae
with Reduced Carbapenem Susceptibility
Authors: Endimiani Andrea , Perez Federico , Bajaksouzian Saralee , Windau Anne R. , Good Caryn E. , Choudhary Yuvraj , Hujer Andrea M. , Bethel Christopher R. , Bonomo Robert A. , Jacobs Michael R. 
Published: September 2010

ABSTRACT

We studied the accuracy of various susceptibility testing methods, including the 2009, 2010, and updated 2010 CLSI recommendations, to identify
Klebsiella pneumoniae
isolates with reduced susceptibility to carbapenems associated with different mechanisms of resistance. Forty-three wild-type (WT) strains, 42 extended-spectrum β-lactamase (ESBL) producers, 18 ESBL producers with outer membrane porin protein loss (ESBL/Omp strains), and 42
bla
KPC
-possessing
K. pneumoniae
(KPC-Kp) isolates were evaluated. Imipenem (IPM), meropenem (MEM), ertapenem (ERT), and doripenem (DOR) were tested by broth microdilution (BMD), Etest, and disk diffusion (DD), and the modified Hodge test (MHT) was performed using IPM and MEM disks. Results were interpreted according to original as well as recently updated interpretative criteria. MHT was positive for all 42 KPC-Kp isolates and 10 of 18 ESBL/Omp strains and therefore had poor specificity in differentiating between KPC-Kp and ESBL/Omp isolates. Based on the updated CLSI standards, phenotypic susceptibility testing by BMD and DD differentiated most carbapenem-susceptible from carbapenem-nonsusceptible
K. pneumoniae
isolates without the need for MHT, while the Etest method characterized many KPC-Kp isolates as susceptible, and breakpoints may need to be lowered for this method. However, both the original and updated CLSI criteria do not adequately differentiate between isolates in the KPC-Kp group, which are unlikely to respond to carbapenem therapy, and those in the ESBL/Omp group, which are likely to respond to carbapenem therapy if MICs are within pharmacokinetic/pharmacodynamic targets. Further studies are required to determine if there is a clinical need to differentiate between KPC-Kp and ESBL/Omp groups.
Peptide Inhibitors of Flavivirus Entry Derived from the E Protein Stem
Authors: Schmidt Aaron G. , Yang Priscilla L. , Harrison Stephen C. 
Published: September 2010

ABSTRACT
Peptides derived from the “stem” of dengue virus (DV) type 2 (DV2) envelope (E) protein inhibit DV2 infectivity, targeting a late-stage fusion intermediate. We show here that stem peptides from all DV serotypes cross-inhibit DV1 to DV4 but that corresponding peptides derived from related flaviviruses do not. This failure to inhibit infection is not due to poor interaction with the E protein but rather to loss of association with the virion membrane. Residues 442 to 444 of the stem are determinants of inhibition; increasing hydrophobicity in this region increases inhibitory strength. These results support a two-step model of how stem-derived peptides inhibit viral entry.
Structure of a Major Antigenic Site on the Respiratory Syncytial Virus Fusion Glycoprotein in Complex with Neutralizing Antibody 101F
Authors: McLellan Jason S. , Chen Man , Chang Jung-San , Yang Yongping , Kim Albert , Graham Barney S. , Kwong Peter D. 
Published: September 2010

ABSTRACT
Respiratory syncytial virus (RSV) is a major cause of pneumonia and bronchiolitis in infants and elderly people. Currently there is no effective vaccine against RSV, but passive prophylaxis with neutralizing antibodies reduces hospitalizations. To investigate the mechanism of antibody-mediated RSV neutralization, we undertook structure-function studies of monoclonal antibody 101F, which binds a linear epitope in the RSV fusion glycoprotein. Crystal structures of the 101F antigen-binding fragment in complex with peptides from the fusion glycoprotein defined both the extent of the linear epitope and the interactions of residues that are mutated in antibody escape variants. The structure allowed for modeling of 101F in complex with trimers of the fusion glycoprotein, and the resulting models suggested that 101F may contact additional surfaces located outside the linear epitope. This hypothesis was supported by surface plasmon resonance experiments that demonstrated 101F bound the peptide epitope ∼16,000-fold more weakly than the fusion glycoprotein. The modeling also showed no substantial clashes between 101F and the fusion glycoprotein in either the pre- or postfusion state, and cell-based assays indicated that 101F neutralization was not associated with blocking virus attachment. Collectively, these results provide a structural basis for RSV neutralization by antibodies that target a major antigenic site on the fusion glycoprotein.
Specific Alterations of MicroRNA Transcriptome and Global Network Structure in Colorectal Carcinoma after Cetuximab Treatment
Authors: Ragusa Marco , Majorana Alessandra , Statello Luisa , Maugeri Marco , Salito Loredana , Barbagallo Davide , Guglielmino Maria Rosa , Duro Laura R. , Angelica Rosario , Caltabiano Rosario , Biondi Antonio , Di Vita Maria , Privitera Giuseppe , Scalia Marina , Cappellani Alessandro , Vasquez Enrico , Lanzafame Salvatore , Basile Francesco , Di Pietro Cinzia , Purrello Michele 
Published: September 2010

Abstract
The relationship between therapeutic response and modifications of microRNA (miRNA) transcriptome in colorectal cancer (CRC) remains unknown. We investigated this issue by profiling the expression of 667 miRNAs in 2 human CRC cell lines, one sensitive and the other resistant to cetuximab (Caco-2 and HCT-116, respectively), through TaqMan real-time PCR. Caco-2 and HCT-116 expressed different sets of miRNAs after treatment. Specifically, 21 and 22 miRNAs were differentially expressed in Caco-2 or HCT-116, respectively (t test, P &lt; 0.01). By testing the expression of differentially expressed miRNAs in CRC patients, we found that miR-146b-3p and miR-486-5p are more abundant in K-ras–mutated samples with respect to wild-type ones (Wilcoxon test, P &lt; 0.05). Sixty-seven percent of differentially expressed miRNAs were involved in cancer, including CRC, whereas 19 miRNA targets had been previously reported to be involved in the cetuximab pathway and CRC. We identified 25 transcription factors putatively controlling these miRNAs, 11 of which have been already reported to be involved in CRC. On the basis of these data, we suggest that the downregulation of let-7b and let-7e (targeting K-ras) and the upregulation of miR-17* (a CRC marker) could be considered as candidate molecular markers of cetuximab resistance. Global network functional analysis (based on miRNA targets) showed a significant overrepresentation of cancer-related biological processes and networks centered on critical nodes involved in epidermal growth factor receptor internalization and ubiquitin-mediated degradation. The identification of miRNAs, whose expression is linked to the efficacy of therapy, should allow the ability to predict the response of patients to treatment and possibly lead to a better understanding of the molecular mechanisms of drug response. Mol Cancer Ther; 9(12); 3396–409. © 2010 AACR.
The Synthetic Caged Garcinia Xanthone Cluvenone Induces Cell Stress and Apoptosis and Has Immune Modulatory Activity
Authors: Batova Ayse , Altomare Diego , Chantarasriwong Oraphin , Ohlsen Kari L. , Creek Kim E. , Lin You-Chin , Messersmith Amy , Yu Alice L. , Yu John , Theodorakis Emmanuel A. 
Published: September 2010

Abstract
Several caged Garcinia xanthone natural products have potent bioactivity and a documented value in traditional Eastern medicine. Previous synthesis and structure activity relationship studies of these natural products resulted in the identification of the pharmacophore represented by the structure of cluvenone. In the current study, we examined the anticancer activity of cluvenone and conducted gene expression profiling and pathway analyses. Cluvenone was found to induce apoptosis in T-cell acute lymphoblastic leukemia cells (EC50 = 0.25 μmol/L) and had potent growth-inhibitory activity against the NCI60 cell panel, including those that are multidrug-resistant, with a GI50 range of 0.1 to 2.7 μmol/L. Importantly, cluvenone was approximately 5-fold more potent against a primary B-cell acute lymphoblastic leukemia compared with peripheral blood mononuclear cells from normal donors, suggesting that it has significant tumor selectivity. Comparison of cluvenone's growth-inhibitory profile to those in the National Cancer Institute database revealed that compounds with a similar profile to cluvenone were mechanistically unlike known agents, but were associated with cell stress and survival signaling. Gene expression profiling studies determined that cluvenone induced the activation of mitogen-activated protein kinase and NrF2 stress response pathways. Furthermore, cluvenone was found to induce intracellular reactive oxygen species formation. Lastly, the modulation in the expression of several genes associated with T cell and natural killer cell activation and function by cluvenone suggests a role as an immune-modulator. The current work highlights the potential of cluvenone as a chemotherapeutic agent and provides support for further investigation of these intriguing molecules with regard to mechanism and targets. Mol Cancer Ther; 9(11); 2869–78. ©2010 AACR.
Cyclin G–Associated Kinase Is Necessary for Osteosarcoma Cell Proliferation and Receptor Trafficking
Authors: Susa Michiro , Choy Edwin , Liu Xianzhe , Schwab Joseph , Hornicek Francis J. , Mankin Henry , Duan Zhenfeng 
Published: September 2010

Abstract
Osteosarcoma is the most frequent primary malignant bone tumor among the children. The advent of neoadjuvant chemotherapy significantly improved the prognosis of patients with osteosarcoma in the 1980s, but it has since plateaued in the past decades. Recently, one of the most researched areas in sarcoma treatment is tyrosine kinases. Here, we describe research on a serine/threonine kinase, cyclin G–associated kinase (GAK), which has not been reported in osteosarcoma previously. In this study, a lentiviral based human shRNA library was utilized to screen for kinases in KHOS and U-2OS osteosarcoma cells. The expression of GAK was examined in osteosarcoma and the effect on cell proliferation was analyzed by GAK siRNA knockdown. The level of GAK expression and its correlation to prognosis was analyzed in osteosarcoma tissue microarray. The effect of GAK depletion on insulin-like growth factor and epidermal growth factor receptor–mediated signal transduction was analyzed by Western blot. We observed that GAK was overexpressed in both osteosarcoma cell lines and tissue samples when compared with human osteoblasts. GAK knockdown by siRNA decreased cell proliferation in both drug-sensitive and multidrug-resistant osteosarcoma cell lines. Immunohistochemistry of osteosarcoma tissue microarray revealed that overexpression of GAK was associated with poor prognosis. Finally, knockdown of GAK resulted in alterations of receptor trafficking and several downstream proteins. In conclusion, our results suggest that osteosarcoma cell proliferation and survival are dependent on GAK. These findings may lead to the development of new therapeutic options for osteosarcoma. Mol Cancer Ther; 9(12); 3342–50. ©2010 AACR.
TROY (TNFRSF19) Is Overexpressed in Advanced Glial Tumors and Promotes Glioblastoma Cell Invasion via Pyk2-Rac1 Signaling
Authors: Paulino Vincent M. , Yang Zhongbo , Kloss Jean , Ennis Matthew J. , Armstrong Brock A. , Loftus Joseph C. , Tran Nhan L. 
Published: September 2010

Abstract
A critical problem in the treatment of malignant gliomas is the extensive infiltration of individual tumor cells into adjacent brain tissues. This invasive phenotype severely limits all current therapies, and to date, no treatment is available to control the spread of this disease. Members of the tumor necrosis factor (TNF) ligand superfamily and their cognate receptors regulate various cellular responses including proliferation, migration, differentiation, and apoptosis. Specifically, the TNFRSF19/TROY gene encodes a type I cell surface receptor that is expressed on migrating or proliferating progenitor cells of the hippocampus, thalamus, and cerebral cortex. Here, we show that levels of TROY mRNA expression directly correlate with increasing glial tumor grade. Among malignant gliomas, TROY expression correlates inversely with overall patient survival. In addition, we show that TROY overexpression in glioma cells activates Rac1 signaling in a Pyk2-dependent manner to drive glioma cell invasion and migration. Pyk2 coimmunoprecipitates with the TROY receptor, and depletion of Pyk2 expression by short hairpin RNA interference oligonucleotides inhibits TROY-induced Rac1 activation and subsequent cellular migration. These findings position aberrant expression and/or signaling by TROY as a contributor, and possibly as a driver, of the malignant dispersion of glioma cells. Mol Cancer Res; 8(11); 1558–67. ©2010 AACR.
Characterisation of angiotensin II receptors in isolated human subcutaneous resistance arteries
Authors: Ytterberg Hoa , Edvinsson Lars 
Published: September 2010

Subcutaneous arteries have been used as a model for resistance arteries, which are potentially involved in enhanced blood pressure (BP) regulation in man. Angiotensin II (Ang II) is an important regulator of tone, acting via type 1 (AT1-) and type 2 (AT2-) receptor subtypes. The aim of this study was to characterise the Ang II receptors in isolated human subcutaneous arteries, using pharmacological and molecular methods. Subcutaneous arteries were obtained from patients undergoing elective gut surgery and were carefully dissected from the abdominal wall. Cylindrical segments were mounted on two L-shaped metal prongs, one of which was connected to a force-displacement transducer for continuous recording of isometric tension. Concentration-response curves to Ang II were constructed in the presence and absence of various selective AT1-receptor antagonists, candesartan, EXP3174, irbesartan and losartan, and the AT2-receptor antagonist, PD 123319. Responses to Ang II were measured as increases in force (mN) and expressed as a percentage of the response to 60 mM of KCl. Ang II caused a concentration-dependent contraction (pEC50=9.45±0.48, Emax=120±13%). Candesartan and EXP3174 caused concentration-dependent depression of the Emax of Ang II without any major shift of pEC50. Losartan and irbesartan caused a significant, dose-dependent rightward shift of the Ang II contraction-response curve in human subcutaneous arteries. The results show that contractile responses of human subcutaneous arteries are mediated via the AT1-receptor. The AT1-receptor antagonists, candesartan and EXP3174, acted in an insurmountable manner, while losartan and irbesartan were surmountable AT1-receptor antagonists. The AT2-receptor antagonist, PD 123319, (10, 100 nM) had no effect on Ang II-induced contraction. This is supported by the positive identification of mRNA for the human AT 1-receptor by RT-PCR.
Does protein binding modulate the effect of angiotensin II receptor antagonists?
Authors: Maillard Marc P , Centeno Catherine , Frostell-Karlsson Åsa , Brunner Hans R , Burnier Michel 
Published: September 2010

IntroductionAngiotensin II AT 1-receptor antagonists are highly bound to plasma proteins (≥ 99%). With some antagonists, such as DuP-532, the protein binding was such that no efficacy of the drug could be demonstrated clinically. Whether protein binding interferes with the efficacy of other antagonists is not known. We have therefore investigated in vitro how plasma proteins may affect the antagonistic effect of different AT1-receptor antagonists.MethodsA radio-receptor binding assay was used to analyse the interaction between proteins and the ability of various angiotensin II (Ang II) antagonists to block AT1-receptors. In addition, the Biacore technology, a new technique which enables the real-time monitoring of binding events between two molecules, was used to evaluate the dissociation rate constants of five AT1-receptor antagonists from human serum albumin.ResultsThe in vitro AT 1-antagonistic effects of different Ang II receptor antagonists were differentially affected by the presence of human plasma, with rightward shifts of the IC50 ranging from one to several orders of magnitude. The importance of the shift correlates with the dissociation rate constants of these drugs from albumin. Our experiments also show that the way that AT1-receptor antagonists bind to proteins differs from one compound to another. These results suggest that the interaction with plasma proteins appears to modulate the efficacy of some Ang II antagonists.ConclusionAlthough the high binding level of Ang II receptor antagonist to plasma proteins appears to be a feature common to this class of compounds, the kinetics and characteristics of this binding is of great importance. With some antagonists, protein binding interferes markedly with their efficacy to block AT1-receptors.
The role of angiotensin II and TGF-beta on the progression of chronic allograft nephropathy
Authors: Weir Matthew R , Chiming Wei  
Published: September 2010

Chronic allograft nephropathy is the most prevalent cause of graft dysfunction and failure. Its pathogenesis and treatment remains poorly defined. The calcineurin inhibitors, cyclosporine and tacrolimus, may play a role in the progressive loss of renal function in patients with chronic allograft nephropathy. This effect may be either related to the direct stimulation of profibrogenic cytokines such as transforming growth factor (TGF-β) or indirect mechanisms, through increases in blood pressure or alterations in either carbohydrate or lipid metabolism. Experimental studies have demonstrated that angiotensin-converting enzyme inhibitors (ACE-I) and angiotensin II receptor blockers (ARBs) can attenuate cyclosporine-mediated increases in TGF-β production in renal tissue. Clinical studies have demonstrated that either cyclosporine or tacrolimus dose reduction may help reduce the rate of loss of renal function in patients with chronic allograft nephropathy. Moreover, other studies have demonstrated that a chronic reduction in the dose of cyclosporine in transplant patients can reduce serum TGF-β levels. Treatment with an ARB can normalise the plasma levels of TGF-β in renal transplant patients receiving cyclosporine. All these observations suggest that there may be a role of cyclosporine, and possibly tacrolimus, in worsening chronic allograft nephropathy through their effects on the renin-angiotensin-aldosterone system (RAAS) and TGF-β production.
Rho-mDia1 pathway is required for adhesion, migration, and T-cell stimulation in dendritic cells
Authors: Tanizaki Hideaki , Egawa Gyohei , Inaba Kayo , Honda Tetsuya , Nakajima Saeko , Moniaga Catharina Sagita , Otsuka Atsushi , Ishizaki Toshimasa , Tomura Michio , Watanabe Takeshi , Miyachi Yoshiki , Narumiya Shuh , Okada Takaharu , Kabashima Kenji 
Published: September 2010

AbstractDendritic cells (DCs) are essential for the initiation of acquired immune responses through antigen acquisition, migration, maturation, and T-cell stimulation. One of the critical mechanisms in this response is the process actin nucleation and polymerization, which is mediated by several groups of proteins, including mammalian Diaphanous-related formins (mDia). However, the role of mDia in DCs remains unknown. Herein, we examined the role of mDia1 (one of the isoforms of mDia) in DCs. Although the proliferation and maturation of bone marrow-derived DCs were comparable between control C57BL/6 and mDia1-deficient (mDia1−/−) mice, adhesion and spreading to cellular matrix were impaired in mDia1−/− bone marrow–derived DCs. In addition, fluorescein isothiocyanate-induced cutaneous DC migration to draining lymph nodes in vivo and invasive migration and directional migration to CCL21 in vitro were suppressed in mDia1−/− DCs. Moreover, sustained T-cell interaction and T-cell stimulation in lymph nodes were impaired by mDia1 deficiency. Consistent with this, the DC-dependent delayed hypersensitivity response was attenuated by mDia1-deficient DCs. These results suggest that actin polymerization, which is mediated by mDia1, is essential for several aspects of DC-initiated acquired immune responses.
Loss of tonic T-cell receptor signals alters the generation but not the persistence of CD8+ memory T cells
Authors: Wiehagen Karla R. , Corbo Evann , Schmidt Michelle , Shin Haina , Wherry E. John , Maltzman Jonathan S. 
Published: September 2010

Abstract
The requirements for tonic T-cell receptor (TCR) signaling in CD8+ memory T-cell generation and homeostasis are poorly defined. The SRC homology 2 (SH2)-domain–containing leukocyte protein of 76 kDa (SLP-76) is critical for proximal TCR-generated signaling. We used temporally mediated deletion of SLP-76 to interrupt tonic and activating TCR signals after clearance of the lymphocytic choriomeningitis virus (LCMV). SLP-76–dependent signals are required during the contraction phase of the immune response for the normal generation of CD8 memory precursor cells. Conversely, LCMV-specific memory CD8 T cells generated in the presence of SLP-76 and then acutely deprived of TCR-mediated signals persist in vivo in normal numbers for more than 40 weeks. Tonic TCR signals are not required for the transition of the memory pool toward a central memory phenotype, but the absence of SLP-76 during memory homeostasis substantially alters the kinetics. Our data are consistent with a model in which tonic TCR signals are required at multiple stages of differentiation, but are dispensable for memory CD8 T-cell persistence.
Formin INF2 regulates MAL-mediated transport of Lck to the plasma membrane of human T lymphocytes
Authors: Andrés-Delgado Laura , Antón Olga M. , Madrid Ricardo , Byrne Jennifer A. , Alonso Miguel A. 
Published: September 2010

AbstractExpression of the src-family kinase lymphocyte-specific protein tyrosine kinase (Lck) at the plasma membrane is essential for it to fulfill its pivotal role in signal transduction in T lymphocytes. MAL, an integral membrane protein expressed in specific types of lymphoma, has been shown to play an important role in targeting Lck to the plasma membrane. Here we report that MAL interacts with Inverted Formin2 (INF2), a formin with the atypical property of promoting not only actin polymerization but also its depolymerization. In Jurkat T cells, INF2 colocalizes with MAL at the cell periphery and pericentriolar endosomes and along microtubules. Videomicroscopic analysis revealed that the MAL+ vesicles transporting Lck to the plasma membrane move along microtubule tracks. Knockdown of INF2 greatly reduced the formation of MAL+ transport vesicles and the levels of Lck at the plasma membrane and impaired formation of a normal immunologic synapse. The actin polymerization and depolymerization activities of INF2 were both required for efficient Lck targeting. Cdc42 and Rac1, which bind to INF2, regulate Lck transport in both Jurkat and primary human T cells. Thus, INF2 collaborates with MAL in the formation of specific carriers for targeting Lck to the plasma membrane in a process regulated by Cdc42 and Rac1.