bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rac1 activation inhibits E-cadherin-mediated adherens junctions via binding to IQGAP1 in pancreatic carcinoma cells
Authors: Hage Beatrix , Meinel Katrin , Baum Iris , Giehl Klaudia , Menke Andre 
Published: September 2009

Abstract

Background
Monomeric GTPases of the Rho family control a variety of cellular functions including actin cytoskeleton organisation, cell migration and cell adhesion. Defects in these regulatory processes are involved in tumour progression and metastasis. The development of metastatic carcinoma is accompanied by deregulation of adherens junctions, which are composed of E-cadherin/β- and α-catenin complexes.

Results
Here, we show that the activity of the monomeric GTPase Rac1 contributes to inhibition of E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells. Stable expression of constitutively active Rac1(V12) reduced the amount of E-cadherin on protein level in PANC-1 pancreatic carcinoma cells, whereas expression of dominant negative Rac1(N17) resulted in an increased amount of E-cadherin. Extraction of proteins associated with the actin cytoskeleton as well as coimmunoprecipitation analyses demonstrated markedly decreased amounts of E-cadherin/catenin complexes in Rac1(V12)-expressing cells, but increased amounts of functional E-cadherin/catenin complexes in cells expressing Rac1(N17). Cell aggregation and migration assays revealed, that cells containing less E-cadherin due to expression of Rac1(V12), exhibited reduced cell-cell adhesion and increased cell motility. The Rac/Cdc42 effector protein IQGAP1 has been implicated in regulating cell-cell adhesion. Coimmunoprecipitation studies showed a decrease in the association between IQGAP1 and β-catenin in Rac1(V12)-expressing PANC-1 cells and an association of IQGAP1 with Rac1(V12). Elevated association of IQGAP1 with the E-cadherin adhesion complex via β-catenin correlated with increased intercellular adhesion of PANC-1 cells.

Conclusion
These results indicate that active Rac1 destabilises E-cadherin-mediated cell-cell adhesion in pancreatic carcinoma cells by interacting with IQGAP1 which is associated with a disassembly of E-cadherin-mediated adherens junctions. Inhibition of Rac1 activity induced increased E-cadherin-mediated cellular adhesion.
A practical approach for the validation of sterility, endotoxin and potency testing of bone marrow mononucleated cells used in cardiac regeneration in compliance with good manufacturing practice
Authors: Soncin Sabrina , Lo Cicero Viviana , Astori Giuseppe , Soldati Gianni , Gola Mauro , Sürder Daniel , Moccetti Tiziano 
Published: September 2009

Abstract

Background
Main scope of the EU and FDA regulations is to establish a classification criterion for advanced therapy medicinal products (ATMP). Regulations require that ATMPs must be prepared under good manufacturing practice (GMP). We have validated a commercial system for the determination of bacterial endotoxins in compliance with EU Pharmacopoeia 2.6.14, the sterility testing in compliance with EU Pharmacopoeia 2.6.1 and a potency assay in an ATMP constituted of mononucleated cells used in cardiac regeneration.

Methods
For the potency assay, cells were placed in the upper part of a modified Boyden chamber containing Endocult Basal Medium with supplements and transmigrated cells were scored. The invasion index was expressed as the ratio between the numbers of invading cells relative to cell migration through a control insert membrane.
For endotoxins, we used a commercially available system based on the kinetic chromogenic LAL-test. Validation of sterility was performed by direct inoculation of TSB and FTM media with the cell product following Eu Ph 2.6.1 guideline.

Results and discussion
The calculated MVD and endotoxin limit were 780× and 39 EU/ml respectively. The 1:10 and 1:100 dilutions were selected for the validation. For sterility, all the FTM cultures were positive after 3 days. For TSB cultures, Mycetes and B. subtilis were positive after 5 and 3 days respectively. The detection limit was 1-10 colonies.
A total of four invasion assay were performed: the calculated invasion index was 28.89 ± 16.82% (mean ± SD).

Conclusion
We have validated a strategy for endotoxin, sterility and potency testing in an ATMP used in cardiac regeneration. Unlike pharmaceutical products, many stem-cell-based products may originate in hospitals where personnel are unfamiliar with the applicable regulations. As new ATMPs are developed, the regulatory framework is likely to evolve. Meanwhile, existing regulations provide an appropriate structure for ensuring the safety and efficacy of the next generation of ATMPs. Personnel must be adequately trained on relevant methods and their application to stem-cell-based products.
The formation of cysteine-linked dimers of BST-2/tetherin is important for inhibition of HIV-1 virus release but not for sensitivity to Vpu
Authors: Andrew Amy J , Miyagi Eri , Kao Sandra , Strebel Klaus 
Published: September 2009

Abstract

Background
The Human Immunodeficiency virus type 1 (HIV-1) Vpu protein enhances virus release from infected cells and induces proteasomal degradation of CD4. Recent work identified BST-2/CD317 as a host factor that inhibits HIV-1 virus release in a Vpu sensitive manner. A current working model proposes that BST-2 inhibits virus release by tethering viral particles to the cell surface thereby triggering their subsequent endocytosis.

Results
Here we defined structural properties of BST-2 required for inhibition of virus release and for sensitivity to Vpu. We found that BST-2 is modified by N-linked glycosylation at two sites in the extracellular domain. However, N-linked glycosylation was not important for inhibition of HIV-1 virus release nor did it affect surface expression or sensitivity to Vpu. Rodent BST-2 was previously found to form cysteine-linked dimers. Analysis of single, double, or triple cysteine mutants revealed that any one of three cysteine residues present in the BST-2 extracellular domain was sufficient for BST-2 dimerization, for inhibition of virus release, and sensitivity to Vpu. In contrast, BST-2 lacking all three cysteines in its ectodomain was unable to inhibit release of wild type or Vpu-deficient HIV-1 virions. This defect was not caused by a gross defect in BST-2 trafficking as the mutant protein was expressed at the cell surface of transfected 293T cells and was down-modulated by Vpu similar to wild type BST-2.

Conclusion
While BST-2 glycosylation was functionally irrelevant, formation of cysteine-linked dimers appeared to be important for inhibition of virus release. However lack of dimerization did not prevent surface expression or Vpu sensitivity of BST-2, suggesting Vpu sensitivity and inhibition of virus release are separable properties of BST-2.
Genotype distribution of cervical human papillomavirus DNA in women with cervical lesions in Bioko, Equatorial Guinea
Authors: García-Espinosa Benjamín , Nieto-Bona MaPaz , Rueda Sonsoles , Silva-Sánchez Luís Fernando , Piernas-Morales MaConcepción , Carro-Campos Patricia , Cortés-Lambea Luís , Moro-Rodríguez Ernesto 
Published: September 2009

Abstract

Background
The HVP vaccine is a useful tool for preventing cervical cancer. The purpose of this study is to determine the most frequent HPV genotypes in Equatorial Guinea in order to develop future vaccination strategies to apply in this country.

Methods
A campaign against cervical cancer was carried out in the area on a total of 1,680 women. 26 of the women, following cytological screening, were treated surgically with a loop electrosurgical excision procedure (LEEP). Cases were studied histologically and were genotyped from paraffin blocks by applying a commercial kit that recognized 35 HPV types.

Results
Cytological diagnoses included 17 HSIL, 1 LSIL, 5 ASC-H and 3 AGUS. Histological diagnosis resulted in 3 cases of microinvasive squamous cell carcinoma stage IA of FIGO, 9 CIN-3, 8 CIN-2, 2 CIN-1, 3 flat condylomas and mild dysplasia of the endocervical epithelium. Fifteen of twenty-five cases genotyped were positive for HPV (60%). HPV 16 and 33 were identified in four cases each, HPV 58 in two other cases, and HPV 18, 31, 52, and 82 in one case, with one HPV 16 and 58 coinfection.

Conclusion
The frequency of HPV types in the African area varies in comparison to other regions, particularly in Europe and USA. Vaccination against the five most common HPV types (16, 33, 58, 18, and 31) should be considered in the geographic region of West Africa and specifically in Equatorial Guinea.
Steroid Receptor RNA Activator Protein (SRAP): a potential new prognostic marker for estrogen receptor-positive/node-negative/younger breast cancer patients
Authors: Yan Yi , Skliris George P , Penner Carla , Chooniedass-Kothari Shilpa , Cooper Charlton , Nugent Zoann , Blanchard Anne , Watson Peter H , Myal Yvonne , Murphy Leigh C , Leygue Etienne 
Published: September 2009

Abstract
Introduction
The steroid receptor RNA activator is a functional RNA suspected to participate in the mechanisms underlying breast tumor progression. This RNA is also able to encode for a protein, Steroid Receptor RNA Activator Protein (SRAP), whose exact function remains to be determined. Our aim was to assess, in a large breast cancer cohort, whether levels of this protein could be associated with outcome or established clinical parameters.

Methods
Following antibody validation, SRAP expression was assessed by tissue-microarray (TMA) analysis of 372 breast tumors. Clinical follow-up and parameters such as steroid receptor and node status were available for all the corresponding cases. Immunohistochemical scores were independently determined by three investigators and averaged. Statistical analyses were performed using standard univariate and multivariate tests.

Results
SRAP levels were significantly (Mann-Whitney rank sum test, P < 0.05) higher in estrogen receptor-alpha positive (ER+, n = 271), in progesterone receptor positive (PR+, n = 257) and in older patients (age > 64 years, n = 182). When considering ER+ tumors, PR+ tumors, or younger patients (≤ 64 years), cases with high SRAP expression had a significantly (Mantel-Cox test, P < 0.05) worse breast cancer specific survival (BCSS) than those with low SRAP levels. SRAP also appeared as a very powerful indicator of poor prognostic for BCSS in the subset of ER+, node negative and young breast cancer patients (Cox regression analysis, n = 60, BCSS Hazard Ratio = 8.61, P < 0.006).

Conclusions
Our data suggest that SRAP levels might provide additional information on potential risk of recurrence and negative outcome in a specific set of patients with otherwise good prognosis when considering only estrogen receptor and nodal status.
Nebulized antithrombin limits bacterial outgrowth and lung injury in Streptococcus pneumoniae pneumonia in rats
Authors: Hofstra Jorrit J , Cornet Alexander D , de Rooy Bart F , Vlaar Alexander P , van der Poll Tom , Levi Marcel , Zaat Sebastian AJ , Schultz Marcus J 
Published: September 2009

Abstract
Introduction
Disturbed alveolar fibrin turnover is a cardinal feature of severe pneumonia. Clinical studies suggest that natural inhibitors of coagulation exert lung-protective effects via anticoagulant and possibly also anti-inflammatory pathways. Intravenous infusion of the natural anticoagulants increases the risk of bleeding. Local administration may allow for higher treatment dosages and increased local efficacy while at the same time reducing the risk of bleeding. We evaluated the effect of nebulized anticoagulants on pulmonary coagulopathy and inflammation in a rat model of Streptococcus pneumoniae pneumonia.

Methods
In this randomized controlled in vivo laboratory study rats were challenged intratracheally with S. pneumoniae, inducing pneumonia, and randomized to treatment with normal saline (placebo), recombinant human activated protein C (rh-APC), plasma-derived antithrombin (AT), heparin or danaparoid, by means of nebulization.

Results
S. pneumoniae infection increased pulmonary levels of thrombin-antithrombin complexes and fibrin degradation products. All nebulized anticoagulants significantly limited pulmonary coagulopathy. None of the agents except danaparoid resulted in changes in systemic coagulopathy. Treatment with plasma-derived AT reduced outgrowth of S. pneumoniae and histopathologic damage in lungs. In vitro experiments confirmed outgrowth was reduced in bronchoalveolar lavage fluid (BALF) from rats treated with plasma-derived AT compared with placebo. Neutralizing of cationic components in BALF diminished the inhibitory effects on bacterial outgrowth of BALF, suggesting a role for cationic antimicrobial proteins.

Conclusions
Nebulization of anticoagulants attenuates pulmonary coagulopathy during S. pneumoniae pneumonia in rats while only danaparoid affects systemic coagulation. Nebulized plasma-derived AT reduces bacterial outgrowth and exerts significant lung-protective effects.
Amphiregulin and Epiregulin mRNA Expression in Primary Tumors Predicts Outcome in Metastatic Colorectal Cancer Treated With Cetuximab
Authors: Jacobs Bart , De Roock Wendy , Piessevaux Hubert , Van Oirbeek Robin , Biesmans Bart , De Schutter Jef , Fieuws Steffen , Vandesompele Jo , Peeters Marc , Van Laethem Jean-Luc , Humblet Yves , Pénault-Llorca Frederique , De Hertogh Gert , Laurent-Puig Pierre , Van Cutsem Eric , Tejpar Sabine 
Published: September 2009

Purpose To study the power of the epidermal growth factor receptor (EGFR) epiregulin (EREG) and amphiregulin (AREG) ligands' expression in primary tumors to predict the outcome in patients with chemorefractory metastatic colorectal cancer (cmCRC) treated with the combination of cetuximab and irinotecan. Patients and Methods Gene expression measurements and KRAS mutation analysis were performed on archival formalin-fixed paraffin-embedded primary tumors of 220 cmCRC patients. Response was measured using RECIST (Response Evaluation Criteria in Solid Tumors) criteria. The relation between ligand expression levels and outcome was evaluated using logistic regression for response and Cox regression for survival data. Receiver operating characteristics analysis was performed for response and survival data. CIs for the performance indices were obtained with a nonparametric bootstrap procedure. Findings were externally validated on a series of 67 samples treated in a similar setting. Results In KRAS wild type (WT) patients, there was a significant association between log-transformed ligand expression and response for EREG (odds ratio for objective response, 1.90; 95% CI, 1.27 to 2.83; P = .0005; concordance index [c-index], 0.681) and for AREG (odds ratio for objective response, 1.862; 95% CI, 1.22 to 2.72; P = .0017; c-index, 0.673). In a Cox regression model, dichotomized ligand expression was significantly associated with progression-free survival (PFS) and overall survival (OS). EREG PFS hazard ratio (HR) was 0.41 (95% CI, 0.274 to 0.609; P < .001; time-dependent c-index [Cτ index], 0.640), and AREG PFS HR was 0.43 (95% CI, 0.29 to 0.64; P < .001; Cτ index, 0.627). EREG OS HR was 0.42 (95% CI, 0.28 to 0.63; P < .0001; Cτ index, 0.639), and AREG OS HR was 0.40 (95% CI, 0.27 to 0.64; P < .0001; Cτ index, 0.625). There was no predictive power of ligand expression in patients with KRAS mutation. Conclusion Expression of EGFR ligands in primary tumors significantly predicts outcome in KRAS WT cmCRC treated with cetuximab and irinotecan.
A flow field study of the interaction between a centrifugal compressor impeller and two different volutes
Authors: Dai Y , Engeda A , Cave M , Di Liberti J-L 
Published: September 2009

The interaction between an impeller with one large and one small overhung volute was investigated by both computational fluid dynamics simulation and experimental methods. The large volute was mainly generated by increasing the small volute axial length. The computational model, with k—∊ turbulence model and wall function, has been used to predict the internal flow of both volutes. The effect of volute tongue on the flow in the impeller was analysed at off-design conditions. The flow structure in the volutes was also investigated in detail. The performance test of the two configurations was carried out in the aero test facility at Solar Turbines Inc. A good agreement between experimental data and numerical simulation results was found on both the whole compressor stage performance and the impeller performance. The largest deviation is close to 10 per cent for the compressor stage performance prediction at high mass flowrate only.
Catalytic Mannich-Type Reactions of Sulfonylimidates
Authors: Matsubara Ryosuke , Berthiol Florian , Nguyen Huy V , Kobayashi Shu 
Published: September 2009

Abstract
A novel nucleophile, sulfonylimidate, has been successfully employed in Mannich-type reactions. Due to electron-withdrawing property of sulfonyl group of sulfonylimidate, the acidity of α-proton is enhanced so that sulfonylimidate bearing no activating functional group at α-position is deprotonated by relatively weak base. DBU-catalyzed reactions of sulfonylimidates with protected imines in DMF provided the adducts in high yields with high anti selectivity. This reaction represents a wide substrate scope and a high catalytic turnover. A thorough kinetic study revealed that rate-determining step is most likely deprotonation step in case of Ts-imidate. Alkali earth metal alkoxide and its HMDS salt also catalyze Mannich-type reactions of sulfonylimidates. The reactions catalyzed by Mg(OtBu)2 in DMF provided the adducts with high anti selectivity, while those catalyzed by [Sr(HMDS)2]2 gave syn selectivity. The asymmetric variant of Mannich-type reaction of sulfonylimidate was also achieved. Several transformations of sulfonylimidates to other functional groups were also demonstrated. Finally, direct-type catalytic formation of β-amino acid ester from aldehyde and sulfonylimidate was achieved via in situ formation of sulfonylimine and DBU-assisted hydrolysis of sulfonylimidate.
Cyclopropanation Reactions of Halomethyllithium Carbenoids: A Computational Study of the Effects of Aggregation and Solvation
Authors: Pratt Lawrence M , Trần Phương Thảo Thị , Nguỹên Ngân Van , Ramachandran Bala 
Published: September 2009

Abstract
Computational results are presented to support experimental evidence that cyclopropanation reactions of halomethyllithium carbenoids with alkenes occur through the concerted (methylene transfer) pathway rather than the alternate stepwise (carbometalation) pathway in non-polar and polar (THF, ε = 7.85) media. These results complement and confirm the recent findings of Ke, Zhao, and Phillips (KZP) [J. Org. Chem.2007, 72, 848] for ethylene in nonpolar and moderately polar (DME, ε = 4.34) solvents. We also studied carbenoid reactions with 2,3-dimethyl-2-butene. The explanation for the preference for the concerted pathway is provided by detailed examination of the reaction pathways of aggregated carbenoid species, which are the dominant reactive species in both polar and nonpolar solvents. The details of the syn and anti eliminations of lithium halide from the intermediate formed in the two-step mechanism with ethylene are also studied for the first time. Two stable dimeric structures were identified for the carbenoids and both have been studied. By explicit coordination of the monomeric and dimeric organolithium species to THF ligands, we also find that a clear preference for the concerted pathway is shown by both monomers and dimers in polar solvents, and solvent steric factors are dominant in determining the relative stabilities of the aggregates of the carbenoid species in THF solution.
Color Tuning Mechanism of Human Red, Green, and Blue Cone Pigments: SAC-CI Theoretical Study
Authors: Fujimoto Kazuhiro , Hasegawa Jun-ya , Nakatsuji Hiroshi 
Published: September 2009

Abstract
Human red (HR), green (HG), and blue (HB) cone pigments are responsible for human color vision, and their photoabsorption wavelengths spread uniquely over the three primary colors. These pigments, however, include only one common chromophore, retinal. Here, we report physical basis of the color tuning in human vision on the basis of SAC-CI calculations for excited states of the cone pigments. The dominant origin of the red–green–blue distinction lies in differences in electrostatic interactions between retinal and its surrounding proteins. Structural distortion effect of the retinal chromophore is important in human blue pigment. Detailed analysis on individual roles of amino acids within these proteins has clarified elaborate mechanisms of the color tuning, in accordance with previous mutagenesis experiments. Furthermore, the color tuning is regulated by amino acids at specific positions in the proteins, suggesting some genetic origins for the color tuning.
Reaction Paths toward Isocyanate Adducts
Authors: Hatanaka Masashi 
Published: September 2009

Abstract
Addition reactions of isocyanates were theoretically investigated. The simplest model compounds for urethanes, thiourethanes, and ureas were analyzed to find bimolecular reaction profiles. The transition states suggested intramolecular hydrogen-transfer processes, in which highly acidic hydrogens hopped.
One-Pot Two-Step Solvent-Free Rapid and Clean Synthesis of 2-(Substituted Amino)pyrimidines by Microwave Irradiation
Authors: Goswami Shyamaprosad , Hazra Anita , Jana Subrata 
Published: September 2009

Abstract
A series of diversely 2-(substituted amino)pyrimidines (along with ring substitution) has been synthesized under solvent- and catalyst-free microwave conditions from substituted guanidines and β-diketones. The substituted guanidines are synthesized from (S)-methylisothiourea sulfate and different amines (various alkyl, aryl, or heterocyclic and also chiral amines) under microwave irradiation. These two-step reactions are performed in one-pot without isolating any intermediate. This protocol has been successfully applied for the synthesis of bisaminopyrimidines and 2-substituted aminopyrimidines containing chiral moiety where chirality remains undisturbed.
Synthesis of Derivatives of Phenanthrene and Helicene by Improved Procedures of Photocyclization of Stilbenes
Authors: Talele Harish R , Gohil Monik J , Bedekar Ashutosh V 
Published: September 2009

Abstract
An improved method has been developed for photocyclization of stilbene to construct phenanthrenes and benzo[c]phenanthrenes. This reaction is promoted by iodine while tetrahydrofuran is used as an efficient and inexpensive scavenger of hydroiodic acid produced during the photocyclization sequence. In another process, cyclohexene is used as a reagent for dehydrogenation step in place of THF–I2.
Lean NOx Reduction by Hydrogen over Pt-Supported Rare Earth Oxide Catalysts and Their In Situ DRIFTs Study
Authors: Itoh Masahiro , Motoki Koji , Saito Makoto , Iwamoto Jun , Machida Ken-ichi 
Published: September 2009

Abstract
The Pt-supported rare earth oxide (CeO2, Pr6O11, Eu2O3, and Gd2O3) catalysts were prepared and their selective catalytic reduction (SCR) characteristics for NOx using hydrogen were investigated under 10 vol % excess oxygen conditions. Among them, only the Pt/CeO2 catalyst provided good NO conversion (ca. 80%) with ca. 40% N2 selectivity. Other catalysts hardly showed NOx reduction activity due to the high solid basicity of supporting materials. In situ diffuse reflectance infrared Fourier transform spectroscopy (DRIFTs) measurements for the Pt/CeO2 catalyst were performed to obtain the specific adsorption bands assigned to NO3− species, indicating that NOx reduction proceeds via formation of such nitrate.