bluuebunny/crossref_metadata_2025_split huggingface dataset:
Role of Foxp3‐positive regulatory T cells during infection
Authors: Belkaid Yasmine 
Published: April 2008

AbstractSurviving an infection requires the generation of an immune response that controls the invading pathogen while limiting collateral damage to self tissues that may result from an exuberant immune response. Various populations of regulatory cells, including Foxp3+ Treg, have been shown to play a central role in the establishment of these controlled immune responses. In this review, I discuss current hypotheses and points of polemic associated with the origin, mode of action and antigen specificity of Foxp3+ Treg during infection.See accompanying commentary: http://dx.doi.org/10.1002/eji.200738104
Regulatory T cells and immune computation
Authors: Quintana Francisco J. , Cohen Irun R. 
Published: April 2008

AbstractThe role of Treg in immune regulation is the topic of this Viewpoint series in the European Journal of Immunology (EJI); the question to be discussed in this section is the effector function of Treg in immune regulation. In this manuscript, we take on the following three postulates outlined by Rolf Zinkernagel on the role of Treg in the control of immunity. First, the immune response is regulated primarily by the antigen and not by Treg. Second, immune non‐responsiveness results from the deletion of specific receptor‐bearing T cells. Third, there is no definitive proof of the existence of specialized Treg that know what is needed for an equilibrated immune response. Herein, we discuss data demonstrating the existence of specialized Treg and therefore arguing against the validity of the first two postulates. However, based on the reactive nature of the immune system, we agree with Rolf’s third postulate in that Treg cannot know ahead of time an ideal set‐point for immune homeostasis.See accompanying commentary: http://dx.doi.org/10.1002/eji.200738114
The Noncarbonylative Photochemistry of Group 6 Fischer Carbene Complexes
Authors: Fernández Israel , Sierra Miguel A. , Mancheño María José , Gómez‐Gallego Mar , Cossío Fernando P. 
Published: April 2008

AbstractThe different photochemical reaction mechanisms of group 6 Fischer carbene complexes have been studied by a joint experimental and density functional theory (DFT) computational study. This study unifies the photochemcal behavior of group 6 metal carbene complexes (M = Cr or W), which may occur by three different photoreactions, namely photocarbonylation, stepwise 1,2‐dyotropic rearrangement, and α‐fragmentation. The metal atom and the substituent on the nitrogen atom attached to the carbene carbon atom influence the topography of the potential energy surface, which leads to two different activated species, diradicals or metallacyclopropanones. Complexes having a hydrogen substituent at the nitrogen atom experience a stepwise dyotropic migration with no significant differences between the chromium‐ and tungsten–carbene complexes. The excitation of complexes having substituents other than hydrogen at the nitrogen atom leads to two different T1 species, and hence to the formation of mixtures of products arising from α‐fragmentation (noncarbonylation) and amino esters (photocarbonylation). The two triplet states are isoenergetic in the Cr derivatives, but the T1 species that leads to α‐fragmentation is strongly favored for the W derivatives. Finally, both the chromium‐ and tungsten–carbene complexes are photoreactive in spite of the longstanding claim that tungsten–carbene complexes were photochemically inert. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Helical Porphyrinoids: Incorporation of Ferrocene Subunits into Macrocyclic Structures
Authors: Stępień Marcin , Simkowa Irena , Latos‐Grażyński Lechosław 
Published: April 2008

AbstractFerrocene‐containing porphyrinoids have been synthesized in which ferrocene‐1,1′‐diyl units are linked to a dipyrrin or thiatripyrrin to form macrocyclic structures. NMR spectroscopic evidence shows that these new systems adopt helical conformations that undergo an inversion process in solution. In addition, small amounts of unexpected scrambling products have been isolated and characterized, namely a dipyrrin‐bisferrocenophane and two expanded bis(ferrocene) macrocycles. The formation of these systems, which contain macrocyclic rings of different sizes, is a consequence of the structural flexibility of the ferrocene unit. Cyclic voltammetry shows that ferrocene oxidation is reversible in all the systems reported here, and that it is finely tuned by the properties of the ring system. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008)
Direct Electrochemistry of Hemoglobin Entrapped in Composite Electrodeposited Chitosan‐Multiwall Carbon Nanotubes and Nanogold Particles Membrane and Its Electrocatalytic Application
Authors: Liu Chuanyin , Hu Jiming 
Published: April 2008

AbstractHemoglobin was entrapped in composite electrodeposited chitosan‐multiwall carbon nanotubes (MCNTs) film by assembling gold nanoparticles and hemoglobin step by step. In phosphate buffer solution (pH 7), a pair of well‐defined and quasireversible redox peaks appeared with formal potential at −0.289 V and peak separation of 100 mV. The redox peaks respected for the direct electrochemistry of hemoglobin at the surface of chitosan‐MCNTs‐gold nanoparticles modified electrode. The parameters of experiments have also been optimized. The composite electrode showed excellent electrocatalysis to peroxide hydrogen and oxygen, the peak current was linearly proportional to H2O2 concentration in the range from 1×10−6 mol/L to 4.7×10−4 mol/L with a detection limit of 5.0×10−7 mol/L, and this biosensor exhibited high stability, good reproducibility and better selectivity. The biosensor showed a Michaelis–Menten kinetic response as H2O2 concentration is larger than 5.0×10−4 mol/L, the apparent Michaelis–Menten constant for hydrogen peroxide was calculated to be 1.61 μmol/L.
Ordered Mesoporous Carbon Paste Electrodes for Electrochemical Sensing and Biosensing
Authors: Zhu Liande , Tian Chunyuan , Zhu Dongxia , Yang Ruilan 
Published: April 2008

AbstractSurface renewable ordered mesoporous carbon paste electrodes (OMCPE) were prepared by mechanical mixing ordered mesoporous carbon (OMC) and mineral oil. Electrochemical behavior of the composite electrode was evaluated and compared with the conventional graphite paste (GPE) and carbon nanotubes paste (CNTPE) electrodes. The OMCPE provided improved electron transfer kinetics and catalytic capabilities in connection with oxidation and/or reduction of different redox systems, such as ferricyanide and some biological species, e. g. ascorbic acid (AA), uric acid (UA), β‐nicotinamide adenine dinucleotide (NADH), dopamine (DA), epinephrine (EP), acetaminophenol (AP) and hydrogen peroxide. The substantial decrease in the over voltage of the hydrogen peroxide oxidation along with the facile incorporation of glucose oxidase (GOD) into the composite matrix allowed us successfully to fabricate a sensitive and selective glucose biosensor. A linear response up to 15 mM glucose was obtained for the OMCPE modified with 10% GOD (w/w) with a detection limit of 0.072 mM. In addition, we also successfully applied the OMCPE to the anodic stripping voltammetric analysis of heavy metal ions with improved sensitivities in comparison with CNTPE and GPE. The excellent experimental results implicate that the new developed paste electrode holds great promise in the design of electrochemical devices, such as sensors and biosensors.
Photo‐Induced Electron Transfer Between Photosystem 2 via Cross‐linked Redox Hydrogels
Authors: Badura Adrian , Guschin Dmitrii , Esper Berndt , Kothe Tim , Neugebauer Sebastian , Schuhmann Wolfgang , Rögner Matthias 
Published: April 2008

AbstractPhotosystem 2 (PS2) that catalyses light driven water splitting in photosynthesis was ‘wired’ to electrode surfaces via osmium‐containing redox polymers based on poly(vinyl)imidazol. The redox polymer hydrogel worked as both immobilization matrix and electron acceptor for the enzyme. Upon illumination, the enzymatic reaction could be switched on and a catalytic current was observed at the electrode. The catalytic current is directly dependent on the intensity of light used for the excitation of PS2. A typical current density of 45 μA cm−2at a light intensity of 2.65 mW cm−2could be demonstrated with a significantly improved operational stability.
Chromosome 11 genomic changes in parathyroid adenoma and hyperplasia: Array CGH, FISH, and tissue microarrays
Authors: Yi Y. , Nowak Norma J. , Pacchia Annmarie L. , Morrison Carl 
Published: April 2008

AbstractWe have used a combination of gene expression profiling, array comparative genomic hybridization (aCGH), fluorescent in situ hybridization (FISH) and tissue microarrays (TMAs) to investigate chromosome 11 genetic changes in subsets of benign parathyroid tumors. Integration of gene expression profiling and aCGH was done using differential gene locus mapping analysis. We have identified three distinct relatively common chromosome 11 genomic changes in various subsets of parathyroid tumors. The simplest and least common of these genomic changes involves translocation of the CCND1 gene with subsequent strong CCND1 expression. This genetic change is essentially limited to parathyroid adenomas (8%), although expression of CCND1 without translocation is common in uremic hyperparathyroidism. Not surprisingly, deletion of the MEN1 locus at 11q13 or loss of a large portion or an entire chromosome 11 was a common finding. This particular genomic change appears to have a prominent effect on the overall results of gene expression profiling and was present in slightly less than one‐half of adenomas. Genomic changes in primary nonfamilial hyperplasia were for the most part restricted to 11q13 deletion or loss of chromosome 11. The third genomic change we identified was 11q23 deletion. This genetic change was relatively independent of other chromosome 11 changes and present in slightly less than one‐half of adenomas. 11q23 deletion along with relatively strong CCND1 expression was common in uremic hyperparathyroidism. © 2008 Wiley‐Liss, Inc.
Microhomologies and interspersed repeat elements at genomic breakpoints in chronic myeloid leukemia
Authors: Mattarucchi Elia , Guerini Vittoria , Rambaldi Alessandro , Campiotti Leonardo , Venco Achille , Pasquali Francesco , Lo Curto Francesco , Porta Giovanni 
Published: April 2008

AbstractReciprocal translocation t(9;22) is central to the pathogenesis of chronic myeloid leukemia. Some authors have suggested that Alu repeats facilitate this process, but supporting analyses have been sparse and often anecdotal. The purpose of this study was to analyze the local structure of t(9;22) translocations and assess the relevance of interspersed repeat elements at breakpoints. Collected data have been further compared with the current models of DNA recombination, in particular the single‐strand annealing (SSA) and the nonhomologous end joining (NHEJ) processes. We developed a protocol for the rapid characterization of patient‐specific genomic junctions and analyzed 27 patients diagnosed with chronic myeloid leukemia. Sequence analysis revealed microhomologies at the junctions of 21 patients of 27, while interspersed repeats were of relevance (P < 0.05) in at least 16 patients. These findings are more frequent than expected and give an indication that the main mechanisms involved in the t(9;22) translocation are the SSA and NHEJ pathways, both playing a role. Furthermore, our report is consistent with microhomologies facilitating the joining of DNA ends in the translocation process, and with both Alu and a variety of other repeat sequences pairing nonhomologous chromosomes during the SSA pathway. © 2008 Wiley‐Liss, Inc.
Two case studies illustrating how relatively selective hippocampal lesions in humans can have quite different effects on memory
Authors: Holdstock J.S. , Parslow D.M. , Morris R.G. , Fleminger S. , Abrahams S. , Denby C. , Montaldi D. , Mayes A.R. 
Published: April 2008

AbstractTwo patients, with magnetic resonance imaging (MRI)‐confirmed relatively selective hippocampal damage, showed distinct patterns of performance on tests of recall, item recognition, and associative recognition. Patient AC showed a mean bilateral volume reduction of the hippocampus of 28%, but displayed no memory deficit. Both recall and recognition memory were unimpaired. In contrast, patient PR, who showed a mean bilateral hippocampal volume reduction of 59%, was more consistently impaired on recall than recognition tests, although his recognition scores were highly variable. Patients AC and PR illustrate how variable the memory deficit following seemingly selective hippocampal damage can be in humans. They highlight the need for more sophisticated imaging in future studies if the human hippocampus' role in memory is to be fully identified. © 2008 Wiley‐Liss, Inc.
Associations between mothers' sensitivity to their infants' internal states and children's later understanding of mind and emotion
Authors: Ereky‐Stevens Katharina 
Published: April 2008

AbstractThis study investigated associations between mother–infant interactions and children's subsequent understanding of mind and emotion. Mothers' tendency to comment on their infants' internal world and their general sensitivity to their infants' internal states were measured through coded play interactions at 10 months. The latter measurement included ratings on four aspects of maternal behaviour: mindful facilitation, joint attention commenting, pacing, and affect catching. In contrast to mothers' internal state language, these behaviours did not tap mothers' explicit linguistic representation of their infants' mental states. At 54 months, children's understanding of mind and emotion was measured through a range of false‐belief tasks and an emotion‐understanding task. Multivariate analysis revealed direct positive links between mothers' sensitivity to their infants' internal states and children's later understanding of mind. Copyright © 2008 John Wiley & Sons, Ltd.
Gene expression changes during HPV‐mediated carcinogenesis: A comparison between an in vitro cell model and cervical cancer
Authors: Wan Fang , Miao Xijiang , Quraishi Iram , Kennedy Valerie , Creek Kim E. , Pirisi Lucia 
Published: April 2008

AbstractWe used oligonucleotide microarrays to investigate gene expression changes associated with multi‐step human papillomavirus type 16 (HPV16)‐mediated carcinogenesis in vitro. Gene expression profiles in 4 early passage HPV16‐immortalized human keratinocyte (HKc) lines derived from different donors were compared with their corresponding 4 late‐passage, differentiation‐resistant cell lines, and to 4 pools of normal HKc, each composed of 3 individual HKc strains, on Agilent 22 k human oligonucleotide microarrays. The resulting data were analyzed using a modified T‐test coded in R to obtain lists of differentially expressed genes. Gene expression changes identified in this model system were then compared with gene expression changes described in published studies of cervical intraepithelial neoplasia (CIN) and cervical cancer. Common genes in these lists were further studied by cluster analysis. Genes whose expression changed in the same direction as in CIN or cervical cancer (concordant) at late stages of HPV16‐mediated transformation in vitro formed one major cluster, while those that changed in the opposite direction (discordant) formed a second major cluster. Further annotation found that many discordant expression changes involved gene products with an extracellular localization. Two novel genes were selected for further study: overexpression of SIX1 and GDF15, observed during in vitro progression in our model system, was confirmed in tissue arrays of cervical cancer. These microarray‐based studies show that our in vitro model system reflects many cellular and molecular alterations characteristic of cervical cancer, and identified SIX1 and GDF15 as 2 novel potential biomarkers of cervical cancer progression. © 2008 Wiley‐Liss, Inc.
Heregulin‐induced activation of ErbB3 by EGFR tyrosine kinase activity promotes tumor growth and metastasis in melanoma cells
Authors: Ueno Yoko , Sakurai Hiroaki , Tsunoda Satoshi , Choo Min‐Kyung , Matsuo Mitsuhiro , Koizumi Keiichi , Saiki Ikuo 
Published: April 2008

AbstractErbB3 receptor tyrosine kinase has been shown to induce tumor progression in several types of cancer through heterodimerization with ErbB2. However, the role of ErbB3 and its ligand heregulin (HRG) in tumor metastasis remains poorly understood. In the present study, we tried to clarify their contributions to the metastasis of ErbB3‐overexpressing B16‐BL6 melanoma cells. Stimulation with HRG induced phosphorylation of ErbB3 and metastatic properties including MMP‐9 expression, invasion, adhesion and experimental lung metastasis in vivo. These cellular responses were blocked by inhibiting the tyrosine kinase activity of EGFR with PD153035. In addition, phosphorylation of EGFR was rapidly induced by HRG, suggesting that EGFR is a possible heterodimeric counterpart of ErbB3. RNA interference demonstrated that subcutaneous tumor growth and angiogenesis was attenuated by inactivation of ErbB3 in cancer cells. Although experimental pulmonary metastasis was not affected by the knockdown of ErbB3, spontaneous metastasis was, even when primary tumors in the foot pad were amputated at a similar size. These results indicate that HRG‐induced activation of ErbB3 via EGFR promotes tumor growth and metastasis of melanoma cells. © 2008 Wiley‐Liss, Inc.
Persistent downregulation of the pancarcinoma‐associated epithelial cell adhesion molecule via active intranuclear methylation
Authors: van der Gun Bernardina T.F. , Wasserkort Reinhold , Monami Amélie , Jeltsch Albert , Raskó Tamás , Ślaska‐Kiss Krystyna , Cortese Rene , Rots Marianne G. , de Leij Lou F.M.H. , Ruiters Marcel H.J. , Kiss Antal , Weinhold Elmar , McLaughlin Pamela M.J. 
Published: April 2008

AbstractThe epithelial cell adhesion molecule (EpCAM) is expressed at high levels on the surface of most carcinoma cells. SiRNA silencing of EpCAM expression leads to reduced metastatic potential of tumor cells demonstrating its importance in oncogenesis and tumor progression. However, siRNA therapy requires either sequential delivery or integration into the host cell genome. Hence we set out to explore a more definite form to influence EpCAM gene expression. The mechanisms underlying the transcriptional activation of the EpCAM gene, both in normal epithelial tissue as well as in carcinogenesis, are poorly understood. We show that DNA methylation plays a crucial role in EpCAM expression, and moreover, active silencing of endogenous EpCAM via methylation of the EpCAM promoter results in a persistent downregulation of EpCAM expression. In a panel of carcinoma derived cell lines, bisulfite analyses showed a correlation between the methylation status of the EpCAM promoter and EpCAM expression. Treatment of EpCAM‐negative cell lines with a demethylating agent induced EpCAM expression, both on mRNA and protein level, and caused upregulation of EpCAM expression in an EpCAM‐positive cell line. After delivery of the DNA methyltransferase M.SssI into EpCAM‐positive ovarian carcinoma cells, methylation of the EpCAM promoter resulted in silencing of EpCAM expression. SiRNA‐mediated silencing remained for 4 days, after which EpCAM re‐expression increased in time, while M.SssI‐mediated downregulation of EpCAM maintained through successive cell divisions as the repression persisted for at least 17 days. This is the first study showing that active DNA methylation leads to sustained silencing of endogenous EpCAM expression. © 2008 Wiley‐Liss, Inc.
The risk of extra‐colonic, extra‐endometrial cancer in the Lynch syndrome
Authors: Watson Patrice , Vasen Hans F.A. , Mecklin Jukka‐Pekka , Bernstein Inge , Aarnio Markku , Järvinen Heikki J. , Myrhøj Torben , Sunde Lone , Wijnen Juul T. , Lynch Henry T. 
Published: April 2008

AbstractPersons with the Lynch syndrome (LS) are at high risk for cancer, including cancers of the small bowel, stomach, upper urologic tract (renal pelvis and ureter), ovary, biliary tract and brain tumors, in addition to the more commonly observed colorectal and endometrial cancers. Cancer prevention strategies for these less common cancers require accurate, age‐specific risk estimation. We pooled data from 4 LS research centers in a retrospective cohort study, to produce absolute incidence estimates for these cancer types, and to evaluate several potential risk modifiers. After elimination of 135 persons missing crucial information, cohort included 6,041 members of 261 families with LS‐associated MLH1 or MSH2 mutations. All were either mutation carriers by test, probable mutation carriers (endometrial/colorectal cancer‐affected), or first‐degree relatives of these. Among mutation carriers and probable carriers, urologic tract cancer (N = 98) had an overall lifetime risk (to age 70) of 8.4% (95% CI: 6.6–10.8); risks were higher in males (p < 0.02) and members of MSH2 families (p < 0.0001). Ovarian cancer (N = 72) had an lifetime risk of 6.7% (95% CI: 5.3–9.1); risks were higher in women born after the median year of birth (p < 0.008) and in members of MSH2 families (p < 0.006). Brain tumors and cancers of the small bowel, stomach, breast and biliary tract were less common. Urologic tract cancer and ovarian cancer occur frequently enough in some LS subgroups to justify trials to evaluate promising prevention interventions. Other cancer types studied occur too infrequently to justify strenuous cancer control interventions. © 2008 Wiley‐Liss, Inc.
How basal are triple‐negative breast cancers?
Authors: Bertucci François , Finetti Pascal , Cervera Nathalie , Esterni Benjamin , Hermitte Fabienne , Viens Patrice , Birnbaum Daniel 
Published: April 2008

AbstractThe basal molecular subtype of breast cancer (BC) is defined by the mRNA expression pattern of an intrinsic ∼500‐gene set. It is the most homogeneous subtype in transcriptional terms, and one of the most aggressive in prognostic terms. Clinical trials testing new systemic therapeutic strategies have been launched in basal BCs. Although no proof of evidence has yet been reported, basal tumors are currently assimilated to and selected as triple‐negative (TN) BCs in these trials because of their frequent immunohistochemical (IHC) negativity for hormone and ERBB2 receptors. Here, we have assessed the degrees of correlation and of homogeneity of the TN phenotype (IHC‐based definition) and the basal subtype (gene expression‐based definition). We analyzed 172 TN BCs defined by gene expression profile as basal (123 cases) and nonbasal (49 cases). Conversely, 160 tumors were defined as basal by their gene expression profile and included 123 TN and 37 non‐TN samples. Uni‐ and multivariate analyses revealed that TN BCs represent a more heterogeneous group than basal BCs, including basal and nonbasal tumors very different both at the histoclinical and molecular level, notably for mRNA expression of molecules targeted by specific therapies under evaluation in clinical trials. These results call for caution in the interpretation of ongoing trials and selection of patients in future trials. They also warrant the identification of molecular markers for basal BCs more clinically applicable than gene expression profiles. © 2008 Wiley‐Liss, Inc.