bluuebunny/crossref_metadata_2025 huggingface dataset:
The N‐terminus of phosphoinositide 3‐kinase‐C2β regulates lipid kinase activity and binding to clathrin
Authors: Wheeler Matthew , Domin Jan
Published: October 2005

The class II phosphoinositide 3‐kinase (PI3K)‐C2β is recruited to polypeptide growth factor receptors following ligand stimulation. In contrast to the class I A p85/p110 heterodimers, this interaction is dependent upon proline residues present within the N‐terminal sequence of the 3‐phosphoinositide kinase. However, the mechanism by which PI3K‐C2β catalytic activity is regulated currently remains unknown. In many tumours, increased expression of ErbB receptors confers a poor prognosis. We demonstrate that increased expression of EGFR enhanced its association with PI3K‐C2β following stimulation with EGF. Deletion of the first proline rich region within the N‐terminus precluded recruitment of PI3K‐C2β to activated EGFR. Although deletion of the first proline rich motif also rendered the enzyme catalytically inactive, further deletions (residues 1–148 and 1–261) that removed the second and third proline rich motifs increased kinase activity. These data confirm a regulatory role for the N‐terminus of class II PI3K enzymes suggesting that catalytic activity is regulated by factors that associate with this region during recruitment to activated growth factor receptors. Using an N‐terminal PI3K‐C2β‐GST fusion protein, clathrin heavy chain was affinity purified from A431 cell lysates. Association of PI3K‐C2β with clathrin was confirmed by co‐immunoprecipitation from cell lysates while intracellular co‐localisation of PI3K‐C2β and clathrin was confirmed by confocal microscopy. Our findings demonstrate for the first time that the PI3K‐C2β isoform associates with clathrin and thus provides a link between receptor mediated intracellular signalling and clathrin coated vesicle transport. © 2005 Wiley‐Liss, Inc.
Proteasome subunit LMP2 is required for matrix metalloproteinase‐2 and ‐9 expression and activities in human invasive extravillous trophoblast cell line
Authors: Wang Hong‐Xing , Wang Hong‐Mei , Lin Hai‐Yan , Yang Qing , Zhang Heng , Tsang Benjamin K. , Zhu Cheng
Published: October 2005

The ubiquitin‐proteasome pathway (UPP) is involved in the degradation of the extracellular matrix (ECM) and trophoblastic invasion during early pregnancy. Our previous studies demonstrated that inhibition of UPP suppresses expression of matrix metalloproteinase (MMP)‐2 and ‐9. LMP2 is an important proteasome subunit that is critical for proteasome activity. This study investigated the regulatory mechanism of LMP2 on the expression and activities of MMP‐2 and MMP‐9. Our results showed that transfection of LMP2 siRNA plasmid into the human invasive extravillous trophoblast cell line (HTR8/Svneo) could significantly suppress expression of LMP2 mRNA and protein. The mRNA expression of MMP‐2 and MMP‐9 and their activities were markedly decreased in the LMP2‐inhibited cells. Inhibition of LMP2 could also reduce IκBα mRNA level, although the expression of phosphorylated IκBα was increased. In the LMP2‐inhibited cells, expression of mRNA encoding NF‐κB subunits p50 and p65 remained normal, but the p50 protein level was significantly decreased in the cytosolic and nuclear extracts, while p65 protein was markedly reduced only in the nuclear extract. We also demonstrated that blockage of the NF‐κB pathway by the NF‐κB translocation inhibitor SN50 markedly reduced the expression of MMP‐2 and MMP‐9 in HTR8/Svneo cells, a result that is fully consistent with the results from the LMP2‐inhibited HTR8/Svneo cells. These data suggest that LMP2 contributes to IκBα degradation and p50 generation, and that inhibition of LMP2 suppresses expression and activities of MMP‐2 and MMP‐9 by blocking the transfer of active NF‐κB heterodimers into the nucleus. © 2005 Wiley‐Liss, Inc.
Unique human CD133+ leukemia cell line and its modulation towards a mesenchymal phenotype by FGF2 and TGFβ1
Authors: Bodo Maria , Baroni Tiziano , Bellucci Catia , Lilli Cinzia , De Ioanni Maria , Bonifacio Elisabetta , Moretti Lorenzo , Becchetti Ennio , Bellocchio Silvia , Delfini Costante , Lumare Eleonora , Tabilio Antonio
Published: October 2005

Immunological features of GM‐490 cells, a new blood cell line from a patient with acute lymphoblastic leukemia, included lack of CD34, CD38, CD45, CD14, HLA‐DR, and lymphoid and myeloid markers and expression of CD29, CD36, CD44, CD54, CD71, CD105, and CD133. Molecular analysis indicated CD45 gene expression was absent but CD34 mRNA was present. GM‐490 cells constitutively produced fibronectin (FN), type III and traces of type I collagen, collagenases, glycosaminoglycans (GAG) and biglycan and betaglycan proteoglycans (PG) as well as FGF2 and TGFβ1. When FGF2 and/or TGFβ1 were added to cells in vitro, they stimulated cell proliferation and differently modulated matrix production and growth factor receptor expression. Reverse transcription‐polymerase chain reaction (RT‐PCR) detection of transcripts encoding for osteocalcin and RUNX2 suggests GM‐490 cells differentiate towards the osteoblast pathway. GM‐490 cells expressed the low affinity nerve growth factor receptor (p75LNGFR), a somatic stem cell marker that is not detected in hematopoietic cells, leading to the hypothesis that GM‐490 has mesenchymal stem cell properties. The reciprocal modulating effects of FGF2 and TGFβ1 on each other's receptors make the GM‐490 cell line a new model for investigating the relationship between these growth factors and their receptors in autocrine loops which are believed to sustain the malignant clone in hematological diseases. © 2005 Wiley‐Liss, Inc.
Bulk versus surface contributions in nonlinear optics of isotropic centrosymmetric media
Authors: Cattaneo Stefano , Kauranen Martti
Published: October 2005

The relative importance of bulk and surface contributions to the second‐harmonic response of isotropic surfaces is addressed by studying the polarization properties of second‐harmonic signals generated by two noncollinear input beams. Measurements on an air‐glass interface reveal that the bulk contributions dominate in transmission but are negligible in reflection. Even when the nonlinear response has a bulk origin, it is strongly suppressed when the interaction volume is localized deep inside the bulk medium. Conversely, bulk contributions are maximized when the interaction volume is localized near the surface. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optical properties of Si and Ge nanocrystals: Parameter‐free calculations
Authors: Ramos L. E. , Weissker H.‐Ch. , Furthmüller J. , Bechstedt F.
Published: October 2005

An overview is given on the electronic and optical properties of Si and Ge nanocrystals. We model free‐standing Si and Ge nanocrystals passivated with H, with up to 363 group‐IV atoms and 276 H and oxidized nanocrystals with additional silicon oxide shells, e.g. Si41(O60Si42)(O108Si64)H148. The results discussed are based on parameter‐free calculations for relaxed atomic structures. The electronic states and the many‐body effects are considered within the density‐functional theory and the supercell method. Energy gaps are described within the Kohn–Sham independent‐particle picture and within the independent‐quasiparticle picture, whereas electronic excitations are treated within the delta self‐consistent method by pair excitation energies. The projector‐augmented wave method allows the calculation of optical matrix elements, oscillator strengths, optical spectra, and radiative lifetimes. We discuss quantum confinement, structural relaxation, oxidation, and the role of defects in oxidized Si NCs. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Influence of quadratic contributions in magnetization‐induced second harmonic generation studies of magnetization reversal
Authors: Valev V. K. , Gruyters M. , Kirilyuk A. , Rasing Th.
Published: October 2005

Magnetization‐induced optical Second Harmonic Generation (MSHG) from an exchange‐biased CoO/Fe multilayer produces an asymmetrical hysteresis loop that indicates different magnetization reversal behaviour between the interface and the bulk ferromagnet. A more careful analysis of the data demonstrates that this asymmetry is in fact due to a quadratic dependence on the magnetization of the MSHG intensity. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Spin–orbit effects on the optical anisotropy of semiconductor surfaces
Authors: Vázquez‐Nava R. A. , Mendoza B. S. , Arzate N.
Published: October 2005

We study the effects of spin–orbit (SO) coupling on the reflectance anisotropy spectroscopy of semiconductor surfaces. The sp3s* nearest‐neighbor tight‐binding model with allowance for SO interaction is used to obtain theoretical reflectance anisotropy spectra of clean (110)1 × 1 surfaces of III–V semiconductors. We compare our SO‐spectra with the experimental spectra and find good agreement between them. (© 2005 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Vascular Control during Hepatectomy: Review of Methods and Results
Authors: Smyrniotis Vassilios , Farantos Charalampos , Kostopanagiotou Georgia , Arkadopoulos Nikolaos
Published: October 2005

The various techniques of hepatic vascular control are presented, focusing on the indications and drawbacks of each. Retrospective and prospective clinical studies highlight aspects of the pathophysiology, indications, and morbidity of the various techniques of hepatic vascular control. Newer perspectives on the field emerge from the introduction of ischemic preconditioning and laparoscopic hepatectomy. A literature review based on computer searches in Index Medicus and PubMed focuses mainly on prospective studies comparing techniques and large retrospective ones. All methods of hepatic vascular control can be applied with minimal mortality by experienced surgeons and are effective for controlling bleeding. The Pringle maneuver is the oldest and simplest of these methods and is still favored by many surgeons. Intermittent application of the Pringle maneuver and hemihepatic occlusion or inflow occlusion with extraparenchymal control of major hepatic veins is particularly indicated for patients with abnormal parenchyma. Total hepatic vascular exclusion is associated with considerable morbidity and hemodynamic intolerance in 10% to 20% of patients. It is absolutely indicated only when extensive reconstruction of the inferior vena cava (IVC) is warranted. Major hepatic veins/ and limited IVC reconstruction has been also achieved under inflow occlusion with extraparenchymal control of major hepatic veins or even using the intermittent Pringle maneuver. Ischemic preconditioning is strongly recommended for patients younger than 60 years and those with steatotic livers. Each hepatic vascular control technique has its place in liver surgery, depending on tumor location, underlying liver disease, patient cardiovascular status, and, most important, the experience of the surgical and anesthesia team.
18F‐Fluorodeoxyglucose Positron Emission Tomography: Useful Technique for Predicting Malignant Potential of Gastrointestinal Stromal Tumors
Authors: Kamiyama Yoichi , Aihara Ryuusuke , Nakabayashi Toshihiro , Mochiki Erito , Asao Takayuki , Kuwano Hiroyuki , Oriuchi Nobuo , Endo Keigo
Published: October 2005

The malignant potential of gastrointestinal stromal tumors (GISTs) is difficult to diagnose before surgery because the diagnoses are based on tumor diameter and mitotic index. The progression of small GISTs is always observed because they do not seem to have malignant potential. 18F‐Fluorodeoxyglucose (FDG)‐positron emission tomography (PET) is a useful technique for assessing tumor activity. The objective of this study was to determine if FDG‐PET is useful for predicting the malignant potential of gastric GISTs. Ten patients diagnosed with gastric GISTs participated. FDG‐PET was performed on all of them before tumor resection. A whole‐body image was initiated 40 minutes after the injection of 275 to 370 MBq FDG. FDG uptake was assessed by a standardized uptake value. All tumors had FDG uptake. There was a significant correlation between the FDG uptake and both the Ki67 index and the mitotic index but not the tumor diameter. The FDG uptake and malignant potential of gastric GISTs had a significant correlation. FDG‐PET may be of considerable value for predicting the malignant potential of gastric GISTs before surgery. A gastric GIST with a high FDG uptake should be regarded as having malignant potential.
Effect of Neostigmine on Organ Injury in Murine Endotoxemia: Missing Facts about the Cholinergic Antiinflammatory Pathway
Authors: Akinci Seda B. , Ulu Nadir , Yondem Omer Z. , Firat Pinar , Guc M. Oguz , Kanbak Meral , Aypar Ulku
Published: October 2005

Electrical and pharmacologic stimulation of the efferent cholinergic antiinflammatory pathway suppress the systemic inflammatory response and can prevent lethal endotoxemia. Neostigmine, a cholinergic agent, has not been tested to determine if it can prevent histopathologic organ injury in endotoxemia. In the present study, the effects of neostigmine treatment on the histopathologic organ injury inflicted byEscherichia coliendotoxin in a mouse model of septic shock was investigated. Endotoxemia in mice caused weight loss and increased spleen, liver, and lung weight. When the organs were examined for histopathologic injury, endotoxemia increased interstitial inflammation in the lungs, liver injury, and organ injury in general terms; neostigmine, at a dose of 0.1 mg/kg, failed to attenuate these effects. Although the simultaneous administration of neostigmine at a dose of 0.3 mg/kg and endotoxin decreased interstitial inflammation in the lungs, vacuolar degeneration in the liver, and total liver injury, mortality was increased with this dose in the presence of endotoxemia. We conclude that neostigmine at a dose of 0.1 mg/kg was not protective against histopathologic organ injury in mice with endotoxemia, and a higher dose (0.3 mg/kg) was not tolerated probably owing to nonspecific parasympathetic action including cardiovascular effects. Further studies are required to determine the contribution of sites in the cholinergic antiinflammatory pathway.
Surgical Treatment of Chronic Amebic Colitis
Authors: Ozdogan Mehmet , Baykal Atac , Kavuklu Burak , Aran Omer
Published: October 2005

There are limited data concerning the surgical management of chronic amebic colitis (CAC) in the literature. We present our experience with 10 patients with CAC treated surgically. Patients’ records were retrospectively analyzed for age, sex, duration of clinical manifestations, colonoscopic findings, the type of surgical operation, and the postoperative course. Total proctocolectomy and J‐pouch construction was performed in two patients who had CAC with severe rectal involvement. Total colectomy and the Hartmann procedure was performed in eight patients with mild to moderate rectal involvement. This treatment was successful in preserving the rectum in four of the eight. Our results suggest that rectal preservation can be a reliable treatment option in patients with CAC who have mild to moderate rectal involvement. Total proctocolectomy and ileoanal anastomosis with pouch construction should be the treatment of choice for patients with CAC who have severe rectal involvement.
Histological Grading in Gastric Cancer by Ming Classification: Correlation with Histopathological Subtypes, Metastasis, and Prognosis
Authors: Luebke Thomas , Baldus Stephan E. , Grass Guido , Bollschweiler Elfriede , Thiele Jürgen , Dienes Hans‐Peter , Hoelscher Arnulf H. , Moenig Stefan P.
Published: October 2005

The aim of this prospective study was to analyze Ming’s classification in correlation with other currently used classification systems of gastric cancer. In addition, we wanted to define the prognostic significance of the Ming classification system. The present study analyzed material of 117 patients with gastric carcinoma who underwent D2‐gastrectomy with curative intent. All specimens were catagorized according to International Union Against Cancer (UICC) classification, World Health Organization (WHO) classification, Borrmann classification, Laurén classification, Goseki classification, Ming classification, and tumor differentiation. For analysis of correlation between the classification systems, the correlation coefficient according to Spearman was calculated. The survival curves have been calculated according to the Kaplan‐Meier method. According to the Ming classification, 38.5% of the carcinomas exhibited an expanding growth pattern, and 61.5% of specimens showed an infiltrating growth pattern. The subtypes according to the Ming and Laurén classification correlated significantly (P < 0.001). WHO classification (P < 0.001), tumor differentiation (P < 0.001), and Goseki classification (P < 0.001), as well as the macroscopic classification of Borrmann (P < 0.001) and the pT and pN categories of the UICC classification exhibited a highly significant correlation with the Ming classification (P < 0.001 and 0.001, respectively). Median overall survival was 31.3 months. In Kaplan‐Meier analysis, the 3‐year survival rates were lower in the infiltrative tumor type when compared to the expansive tumor type according to Ming (P = 0.0847). In multivariate analysis, only the UICC system presented as an independent prognostic factor in multivariate analysis (P < 0.001). This study shows that the Ming classification correlates significantly with the currently used classification systems for gastric cancer and with the UICC staging system, especially, the pT and pN category. The 3‐year survival rates were lower in the infiltrative tumor type than in the expansive tumor type according to Ming. However, the Ming classification is not an independent prognostic factor.
Salvage Abdominoperineal Resection and Perineal Wound Healing in Local Recurrent or Persistent Anal Cancer
Authors: Ferenschild Floris T.J. , Vermaas Maarten , Hofer Stefan O. , Verhoef Cornelis , Eggermont Alexander M.M. , de Wilt Johannes H.W.
Published: October 2005

The primary treatment for anal cancer is chemoradiation (CRT). Failures after CRT are potentially curable with an abdominoperineal resection (APR). A major problem of surgery in the anal area is poor healing of the perineal wound. Between 1985 and 2000, 129 patients treated for anal cancer were retrospectively reviewed. Of the 24 patients with local failure, 18 patients were treated with an APR. The aim of this study was to review the results and long‐term outcome after salvage APR, with special emphasis on perineal wound healing. Mean age at diagnosis was 59 (range: 41–83) years. After a median of 16 months, only 2 patients developed a local recurrence. The 5‐year overall survival was 30%. In 11 patients the perineal wound was closed primarily, in 3 patients the perineal wound was left open, and in 4 patients a vertical rectus abdominus musculocutaneous (VRAM) flap was used. Perineal wound breakdown occurred in 5 of the 14 patients (36%) not treated with primary muscle reconstruction. In all patients treated with a VRAM flap the perineal wound healed primarily. In the present study salvage APR in recurrent or persistent anal cancer results in good local control and 5‐year overall survival of 30%. When performing an APR a VRAM flap reconstruction should be considered to prevent disabling perineal wound complications.
Early Metastasizing Spindle Epithelial Tumor with Thymus-like Differentiation (SETTLE) of the Thyroid
Authors: Erickson Michelle L. , Tapia Beatriz , Moreno Elsa R. , McKee Milissa A. , Kowalski Diane P. , Reyes-Múgica Miguel
Published: October 2005

Spindle epithelial tumor with thymus-like elements is a rare thyroid lesion of children and young adults thought to be derived from branchial pouch remnants or foci of ectopic thymus. The lesion is poorly understood, and although it was originally believed to follow an indolent clinical course, its potential for late metastasis is becoming generally acknowledged. We have recently seen a unique case of this rare tumor in an 11-year-old boy, in which an unexpected and salient feature is the presence of a micrometastasis in a single lymph node at presentation. With the exception of 1 case with extensively infiltrative tumor and metastatic disease at the time of onset, in all other cases dissemination occurred years after surgical resection of the primary lesion. We review all previously reported cases and provide a detailed study of the histologic and ultrastructural appearances of this lesion.
Clear Cell Adenocarcinoma of the Cervix in a Child without in Utero Exposure to Diethylstilbestrol: A Case Report and Review of the Literature
Authors: Ahrens William A. , Barrón-Rodriguez L. Patricia , McKee Millisa , Rivkees Scott , Reyes-Múgica Miguel
Published: October 2005

We describe the case of a primary cervical tumor in a 6-year-old child that was originally suspected to be an embryonal rhabdomyosarcoma botryoides. Histologic analysis revealed a clear cell adenocarcinoma. Despite a direct search and questioning for maternal exposure to diethylstilbestrol, this was not documented. Clear cell adenocarcinoma is an extremely rare neoplasm that should be kept in the differential diagnosis of cervicovaginal lesions in children, even in the absence of a clinical history of in utero diethylstilbestrol exposure. We discuss the hypothesized pathogenesis and review the literature on this unusual tumor.
Pediatric Sex Cord-Stromal Tumor with Composite Morphology: A Case Report
Authors: Jarzembowski Jason A. , Lieberman Richard W.
Published: October 2005

A 12-year-old female with developmental delay/mental retardation and a family history of gynecologic cancers presented with nonspecific abdominal complaints and was found to have a 4.5-kg, 25- x 23- x 15-cm pelvic mass with solid and cystic components and associated retro-peritoneal and mesenteric lymphadenopathy. Laboratory studies revealed increased serum levels of CA-125 and inhibin B. Histologically, the tumor exhibited several different morphologic appearances including adult granulosa cell tumor, juvenile granulosa cell tumor (with areas of marked atypia), and Sertoli cell tumor. Immunohistochemically, the tumor was positive for calretinin, MIC-2 (CD99), S100 protein, PGP 9.5, and neuron-specific enolase. Electron microscopy of the Sertoli cell tumor-like areas showed Charcot-Bottcher filaments, a distinguishing feature of Sertoli cells. Together, these findings supported a diagnosis of mixed sex cord-stromal tumor including granulosa cell tumor of adult and juvenile types and intermediate- to high-grade Sertoli cell tumor, with large areas of markedly atypical sex cord-stromal tumor.
How to Bring the “Unseen” Proteome to the Limelight via Electrophoretic Pre-Fractionation Techniques
Authors: Righetti Pier Giorgio , Castagna Annalisa , Herbert Ben , Candiano Giovanni
Published: October 2005

The present review reports a panoply of electrophoretic methods as pre-fractionation tools in proteomic investigations in preparation for mass spectrometry or two-dimensional electrophoresis map analysis. Such electrophoretic pre-fractionation protocols include all those electrokinetic methodologies which are performed in free solution, most of them relying on isoelectric focusing steps (although some approaches based on gels and granulated media are also discussed). Devices associated with electrophoretic separations are multi-chamber apparatuses, such as the multi-compartment electrolyzers equipped with either isoelectric membranes or with isoelectric beads, Off-Gel electrophoresis in a multi-cup device and the Rotofor, an instrument also based on a multi-chamber system but exploiting the conventional technique of carrier-ampholyte-focusing. Other free-flow systems, as well as miniaturized chambers, are also described.
Protein Arrays in Functional Genome Research
Authors: Maercker Christian
Published: October 2005

Whole-genome analyses become more and more necessary for pharmaceutical research. DNA chip hybridizations are an important tool for monitoring gene expression profiles during diseases or medical treatment. However, drug target identification and validation as well as an increasing number of antibodies and other polypeptides tested as potential drugs produce an increasing demand for genome-wide functional assays. Protein arrays are an important step into this direction. Peptide arrays and protein expression libraries are useful for the identification of antibodies and for epitope mapping. Antibody arrays allow protein quantification, protein binding studies, and protein phosphorylation assays. Tissue micro-arrays give a detailed information about the localization of macromolecules. More complex interactions can be addressed in cells spotted in array format. Finally, microfluidics chips enable us to describe the communication between cells in a tissue. In this review, possibilities, limitations and chances of different protein array techniques are discussed.
Application of Mass Spectrometry in Proteomics
Authors: Guerrera Ida Chiara , Kleiner Oliver
Published: October 2005

Mass spectrometry has arguably become the core technology in proteomics. The application of mass spectrometry based techniques for the qualitative and quantitative analysis of global proteome samples derived from complex mixtures has had a big impact in the understanding of cellular function. Here, we give a brief introduction to principles of mass spectrometry and instrumentation currently used in proteomics experiments. In addition, recent developments in the application of mass spectrometry in proteomics are summarised. Strategies allowing high-throughput identification of proteins from highly complex mixtures include accurate mass measurement of peptides derived from total proteome digests and multidimensional peptide separations coupled with mass spectrometry. Mass spectrometric analysis of intact proteins permits the characterisation of protein isoforms. Recent developments in stable isotope labelling techniques and chemical tagging allow the mass spectrometry based differential display and quantitation of proteins, and newly established affinity procedures enable the targeted characterisation of post-translationally modified proteins. Finally, advances in mass spectrometric imaging allow the gathering of specific information on the local molecular composition, relative abundance and spatial distribution of peptides and proteins in thin tissue sections.
A Bioinformatics Perspective on Proteomics: Data Storage, Analysis, and Integration
Authors: Kremer Andreas , Schneider Reinhard , Terstappen Georg C.
Published: October 2005

The field of proteomics is advancing rapidly as a result of powerful new technologies and proteomics experiments yield a vast and increasing amount of information. Data regarding protein occurrence, abundance, identity, sequence, structure, properties, and interactions need to be stored. Currently, a common standard has not yet been established and open access to results is needed for further development of robust analysis algorithms. Databases for proteomics will evolve from pure storage into knowledge resources, providing a repository for information (meta-data) which is mainly not stored in simple flat files. This review will shed light on recent steps towards the generation of a common standard in proteomics data storage and integration, but is not meant to be a comprehensive overview of all available databases and tools in the proteomics community.
Upregulating of Fas, integrin β4 and P53 and depressing of PC‐PLC activity and ROS level in VEC apoptosis by safrole oxide
Authors: Zhao Jing , Miao Junying , Zhao Baoxiang , Zhang Shangli
Published: October 2005

Previously, we found that safrole oxide could trigger vascular endothelial cell (VEC) apoptosis. In this study, to investigate its mechanism to induce apoptosis in VECs, the activities of nitric oxide synthetase and phosphatidylcholine specific phospholipase C, the level of reactive oxygen species and the expressions of Fas, integrin β4 and P53 were analyzed. The data showed that safrole oxide induced apoptosis by increasing the expressions of Fas, integrin β4 and P53, and depressing the activity of Ca2+‐independent phosphatidylcholine‐specific phospholipase C and intracellular reactive oxygen species levels in VECs.
Balance of ATPase stimulation and nucleotide exchange is not required for efficient refolding activity of the DnaK chaperone
Authors: Groemping Yvonne , Seidel Ralf , Reinstein Jochen
Published: October 2005

The DnaK system from Thermus thermophilus (DnaKTth) exhibits pronounced differences in organisation and regulation to its mesophile counterpart from Escherichia coli (DnaKEco). While the ATPase cycle of DnaKEco is tightly regulated by the concerted action of the two cofactors DnaJEco and GrpEEco, the DnaKTth system features an imbalance in this cochaperone mediated regulation. GrpETth considerably accelerates the ATP/ADP exchange, but DnaJTth only slightly stimulates ATPase activity, believed to be a key step for chaperone activity of DnaKEco. By in vitro complementation assays, we could not detect significant ATPase‐stimulation of orthologous DnaJTth
· DnaKEco or DnaJEco
· DnaKTth‐complexes as compared to the DnaKEco system, although they were nevertheless active in luciferase refolding experiments. Assistance of protein recovery by DnaK thus seems to be uncoupled of the magnitude of DnaJ mediated ATPase‐stimulation.
Glucose transporter‐2 (GLUT2) promoter mediated transgenic insulin production reduces hyperglycemia in diabetic mice
Authors: Burkhardt Brant R. , Parker Mathew J. , Zhang Y. Clare , Song Sihong , Wasserfall Clive H. , Atkinson Mark A.
Published: October 2005

Insulin production afforded by hepatic gene therapy (HGT) retains promise as a potential treatment for type 1 diabetes, but successful approaches have been limited. We employed a novel and previously untested promoter for this purpose, glucose transporter‐2 (GLUT2) to drive insulin production via delivery by recombinant adeno‐associated virus (rAAV). In vitro, the GLUT2 promoter was capable of robust glucose‐responsive expression in transduced HepG2 human hepatoma cells. Therefore, rAAV constructs were designed to express the furin‐cleavable human preproinsulin B10 gene, under the control of the murine GLUT2 promoter and packaged for delivery with rAAV expressing the type 5 capsid. Streptozotocin‐induced diabetic mice were subjected to hepatic portal vein injection immediately followed by implantation of a sustained‐release insulin pellet to allow time for transgenic expression. All mice injected with the rAAV5‐GLUT2‐fHPIB10 virus remained euglycemic for up to 35 days post‐injection, with 50% euglycemic after 77 days post‐injection. In contrast, mock‐injected mice became hyperglycemic within 15 days post‐injection following dissolution of the insulin pellet. Serum levels of both human insulin and C‐peptide further confirmed successful transgenic delivery by the rAAV5‐GLUT2‐fHPIB10 virus. These findings indicate that the GLUT2 promoter may be a potential candidate for regulating transgenic insulin production for hepatic insulin gene therapy in the treatment of type I diabetes.
Functional overexpression and in vitro re‐association of OpuA, an osmotically regulated ABC‐transport complex from Bacillus subtilis
Authors: Horn Carsten , Bremer Erhard , Schmitt Lutz
Published: October 2005

The osmotically regulated OpuA uptake system from Bacillus subtilis is a member of the SBP‐dependent subfamily of ABC‐transporters. The functional complex, OpuA(A2B2C), catalyzes the osmotically controlled import of the compatible solutes glycine betaine and proline betaine. Here, we describe the purification of the isolated TMS, OpuAB. Stimulated ATPase activity of OpuAA by OpuAB demonstrated that OpuAB adopts a functional fold. An interaction between all subunits could be verified in detergent solution with the highest ATPase stimulation determined for the dimeric NBS in the re‐associated complex in the presence of all transport components plus substrate.
Structure of dimeric ATP synthase from mitochondria: An angular association of monomers induces the strong curvature of the inner membrane
Authors: Dudkina Natalya V. , Heinemeyer Jesco , Keegstra Wilko , Boekema Egbert J. , Braun Hans-Peter
Published: October 2005

Respiration in all cells depends upon synthesis of ATP by the ATP synthase complex, a rotary motor enzyme. The structure of the catalytic moiety of ATP synthase, the so‐called F1 headpiece, is well established. F1 is connected to the membrane‐bound and ion translocating F0 subcomplex by a central stalk. A peripheral stalk, or stator, prevents futile rotation of the headpiece during catalysis. Although the enzyme functions as a monomer, several lines of evidence have recently suggested that monomeric ATP synthase complexes might interact to form a dimeric supercomplex in mitochondria. However, due to its fragility, the structure of ATP synthase dimers has so far not been precisely defined for any organism. Here we report the purification of a stable dimeric ATP synthase supercomplex, using mitochondria of the alga Polytomella. Structural analysis by electron microscopy and single particle analysis revealed that dimer formation is based on specific interaction of the F0 parts, not the F1 headpieces which are not at all in close proximity. Remarkably, the angle between the two F0 part is about 70°, which induces a strong local bending of the membrane. Hence, the function of ATP synthase dimerisation is to control the unique architecture of the mitochondrial inner membrane.
Binding analysis of a psychrotrophic FKBP22 to a folding intermediate of protein using surface plasmon resonance
Authors: Suzuki Yutaka , Win Ohnmar Ye , Koga Yuichi , Takano Kazufumi , Kanaya Shigenori
Published: October 2005

SIB1 FKBP22 is a homodimer, with each subunit consisting of the C‐terminal catalytic domain and N‐terminal dimerization domain. This protein exhibits peptidyl prolyl cis–trans isomerase activity for both peptide and protein substrates. However, truncation of the N‐terminal domain greatly reduces the activity only for a protein substrate. Using surface plasmon resonance, we showed that SIB1 FKBP22 loses the binding ability to a folding intermediate of protein upon truncation of the N‐terminal domain but does not lose it upon truncation of the C‐terminal domain. We propose that the binding site of SIB1 FKBP22 to a protein substrate of PPIase is located at the N‐terminal domain.
CCAAT/enhancer binding protein‐β (C/EBP‐β), a pivotal regulator of the TATA‐less promoter in the rat catalase gene
Authors: Taniguchi Makoto , Hashimoto Mayumi , Hori Naohiro , Sato Kenzo
Published: October 2005

The rat catalase gene carries a TATA‐less promoter and its transcriptional mechanism is interesting because of downregulation in liver injury. We characterized the core element in the promoter and found that C/EBP‐β binding downstream of the transcription initiation site plays a crucial role for transcription. The multiple complexes binding to the promoter were composed of homodimers and heterodimers of C/EBP‐β isoforms. Transduction of the C/EBP‐β gene showed complete reconstitution of multiple binding complexes in HeLa cells, similar to normal liver. Furthermore, C/EBP‐β was observed to bind to the endogenous catalase promoter. These data suggest that multiple complex formation of C/EBP‐β regulates transcription in the TATA‐less catalase promoter.
Differential selectivity of protein modification by the cyclopentenone prostaglandins PGA1 and 15‐deoxy‐Δ12,14‐PGJ2: Role of glutathione
Authors: Gayarre Javier , Stamatakis Konstantinos , Renedo Marta , Pérez-Sala Dolores
Published: October 2005

Cyclopentenone prostaglandins (cyPG) with antiinflammatory and antiproliferative properties have been envisaged as leads for the development of therapeutic agents. Because cyPG effects are mediated in part by the formation of covalent adducts with critical signaling proteins, it is important to assess the specificity of this interaction. By using biotinylated derivatives of 15‐deoxy‐Δ12,14‐PGJ2 (15d‐PGJ2‐B) and PGA1 (PGA1‐B) we herein provide novel evidence for the differential selectivity of protein modification by distinct cyPG. The marked quantitative and qualitative differences in the binding of 15d‐PGJ2‐B and PGA1‐B to cellular proteins were related to a differential reactivity in the presence of glutathione (GSH), both in vitro and in intact cells. Therefore GSH levels may influence not only the intensity but also the specificity of cyPG action.
Novel type aquaporin SIPs are mainly localized to the ER membrane and show cell‐specific expression in Arabidopsis thaliana
Authors: Ishikawa Fumiyoshi , Suga Shinobu , Uemura Tomohiro , Sato Masa H. , Maeshima Masayoshi
Published: October 2005

We investigated the fourth subgroup of Arabidopsis aquaporin, small and basic intrinsic proteins (SIPs). When they were expressed in yeast, SIP1;1 and SIP1;2, but not SIP2;1, gave water‐channel activity. The transient expression of SIPs linked with green fluorescent protein in Arabidopsis cells and the subcellular fractionation of the tissue homogenate showed their ER localization. The SIP proteins were detected in all of the tissues, except for dry seeds. Histochemical analysis of promoter‐β‐glucuronidase fusions revealed the cell‐specific expression of SIPs. SIP1;1 and SIP1;2 may function as water channels in the ER, while SIP2;1 might act as an ER channel for other small molecules or ions.
Inhibition of mitochondrial aldehyde dehydrogenase by nitric oxide‐mediated S‐nitrosylation
Authors: Moon Kwan-Hoon , Kim Bong-Jo , Song Byoung J.
Published: October 2005

Mitochondrial aldehyde dehydrogenase (ALDH2) is responsible for the metabolism of acetaldehyde and other toxic lipid aldehydes. Despite many reports about the inhibition of ALDH2 by toxic chemicals, it is unknown whether nitric oxide (NO) can alter the ALDH2 activity in intact cells or in vivo animals. The aim of this study was to investigate the effects of NO on ALDH2 activity in H4IIE‐C3 rat hepatoma cells. NO donors such as S‐nitrosoglutathione (GSNO), S‐nitroso‐N‐acetylpenicillamine, and 3‐morpholinosydnonimine significantly increased the nitrite concentration while they inhibited the ALDH2 activity. Addition of GSH‐ethylester (GSH‐EE) completely blocked the GSNO‐mediated ALDH2 inhibition and increased nitrite concentration. To directly demonstrate the NO‐mediated S‐nitrosylation and inactivation, ALDH2 was immunopurified from control or GSNO‐treated cells and subjected to immunoblot analysis. The anti‐nitrosocysteine antibody recognized the immunopurified ALDH2 only from the GSNO‐treated samples. All these results indicate that S‐nitrosylation of ALDH2 in intact cells leads to reversible inhibition of ALDH2 activity.
The NK‐lysin derived peptide NK‐2 preferentially kills cancer cells with increased surface levels of negatively charged phosphatidylserine
Authors: Schröder-Borm Hannah , Bakalova Rumiana , Andrä Jörg
Published: October 2005

The NK‐lysin derived peptide NK‐2 is a potent antibacterial, but non‐toxic to a human keratinocyte cell line and of low hemolytic activity. Its target selectivity is based upon a strong binding preference to membranes containing anionic phospholipids, which are normally not found on the surface of human cells. Here, we analyzed the interaction of NK‐2 with normal human lymphocytes and seven different human cancer cell lines and demonstrate that some of these cells expose negatively charged surface phosphatidylserine (PS), which presumably facilitates killing of the cells by NK‐2. This is underlined by the specific intercalation of the peptide into PS‐containing liposomes analyzed by fluorescence‐resonance energy transfer spectroscopy.
Novel sites of cytosolic glutathione peroxidase expression in colon
Authors: Drew Janice E. , Farquharson Andrew J. , Arthur John R. , Morrice Philip C. , Duthie Garry G.
Published: October 2005

Glutathione peroxidases (Gpx) are important moderators of oxidative stress that is implicated in the pathogenesis of numerous diseases including colon cancer. Previous studies report limited examinations of cytosolic glutathione peroxidase location of expression in colon tissue. This study reports evidence of both common sites of Gpx1 and Gpx2 expression in rat colon and sites that are exclusive to each isoform. Semi‐quantitative PCR performed previously demonstrated RNA expression of Gpx1 and Gpx2 in proximal, transverse and distal colon. Mapping the distribution throughout the entire colon has revealed specific, novel sites of glutathione peroxidase expression in colon lymphatic tissue. In situ hybridisation and immunohistochemistry confirmed micro‐anatomical location of Gpx1 within lymphatic tissue and the lamina propria, sub‐mucosa, muscularis and serosa, but not the lumenal epithelium. In situ hybridisation and immunohistochemistry were consistent with reports of microanatomical location of Gpx2 in the lumenal epithelium. Novel sites of Gpx2 expression were also observed in lymphatic tissue. Immunolocalisation in the vicinity of aberrant crypt foci was also examined to further investigate the link between glutathione peroxidases and colon cancer. This did not reveal significant abnormalities, nor did measurement of cytosolic glutathione peroxidase activity or gene expression in colon tissue from rats treated with the colontropic chemical, 1,2‐dimethylhydrazine. These results support the potential for Gpx1 and Gpx2 redundancy in lymphatic tissue, but not in epithelial cells of the colon crypt or in the lamina propria, sub‐mucosa, muscularis or serosa.
Characterization of the dinuclear metal center of Pyrococcus furiosus prolidase by analysis of targeted mutants
Authors: Du Xuelian , Tove Sherry , Kast-Hutcheson Karen , Grunden Amy M.
Published: October 2005

Prolidases are dipeptidases specific for cleavage of Xaa‐Pro dipeptides. Pyrococcus furiosus prolidase is a homodimer having one Co‐bound dinuclear metal cluster per monomer with one tightly bound Co(II) site and the other loosely bound (K
d 0.24 mM). To identify which Co site is tight‐binding and which is loose‐binding, site‐directed mutagenesis was used to modify amino acid residues that participate in binding the Co1 (E‐313 and H‐284), the Co2 site (D‐209) or the bidentate ligand (E‐327). Metal‐content, enzyme activity and CD‐spectra analyses of D209A‐, H284L‐, and E327L‐prolidase mutants show that Co1 is the tight‐binding and Co2 the loose‐binding metal center.
The health service use and cost of eating disorders
Authors: SIMON JUDIT , SCHMIDT ULRIKE , PILLING STEPHEN
Published: October 2005

Background. The economic burden and health service use of eating disorders have received little attention, although such data are necessary to estimate the implications of any changes in clinical practice for patient care and health care resource requirements. This systematic review reports the current international evidence on the resource use and cost of eating disorders.

Method. Relevant literature (1980–2002) was identified from searches of electronic databases and expert contacts.

Results. Two cost-of-illness studies from the UK and Germany, one burden-of-disease study from Australia and 14 other publications with relevant data from the UK, USA, Austria, Denmark and The Netherlands could be identified. In the UK, the health care cost of anorexia nervosa was estimated to be £4·2 million in 1990. In Germany, the health care cost was €65 million for anorexia nervosa and €10 million for bulimia nervosa during 1998. The Australian study reported the health care costs of eating disorders to be Aus$22 million for year 1993/1994. Other costing studies focused mostly on in-patient care reporting highly variable estimates. There is a dearth of research on non-health care costs.

Conclusions. The limited available evidence reflects a general under-detection and under-treatment of eating disorders. Although both cost-of-illness studies may significantly underestimate the costs of eating disorders because of important omitted cost items, other evidence suggests that the economic burden is likely to be substantial. Comprehensive data on the resource use of patients with eating disorders are urgently needed for better estimations, and to be able to determine cost-effective treatment options.
An empirical study of the typology of bulimia nervosa and its spectrum variants
Authors: STRIEGEL-MOORE RUTH H. , FRANKO DEBRA L. , THOMPSON DOUGLAS , BARTON BRUCE , SCHREIBER GEORGE B. , DANIELS STEPHEN R.
Published: October 2005

Background. There is an ongoing debate about the best way to classify eating disorders. This study examined potential subtypes of bulimia nervosa.

Method. Latent class analysis (LCA) was used to identify subtypes of bulimic symptomatology, utilizing data from 234 respondents in a cohort of black and white young women (n=2054). Participants were administered gated screening questions from the Eating Disorders Examination to determine DSM-IV diagnoses of eating disorders.

Results. A 3-class solution was judged best. Class 1, the ‘purger subtype’ (n=116), was characterized by vomiting, the use of fasting/diet pills, and relatively little bingeing. Class 2, the ‘binger subtype’ (n=97) comprised women who engaged in bingeing but minimal compensatory behaviors. Class 3, the ‘binge-purger subtype’ (n=21) had relatively high rates of all symptoms. Findings of differences between the three subtypes on validator variables and differences between the three subtypes compared to non-eating disorder groups suggest validity of the three bulimic subtypes identified in our analyses. Ethnicity and class membership were associated [χ2(3)=21·89, p<0·0001], reflecting a greater percentage of white women than black women in Class 1 and a greater percentage of black women than white women in Class 2.

Conclusions. LCA revealed one subtype that was similar to bulimia nervosa and two subtypes of bulimic symptomatology that did not meet criteria for bulimia nervosa yet appear to be clinically significant. Further study of the psychological correlates, course, and treatment response of these classes would be of clinical interest.
Wie beeinflussen Routinen das Entscheidungsverhalten?
Authors: Betsch Tilmann
Published: October 2005

Zusammenfassung. Erwachsene Personen verfügen über ein großes Repertoire an Routinen, d.h. sie kennen Handlungen, die zielführend für wiederkehrende Entscheidungssituationen sind. Die kognitive Entscheidungsforschung vernachlässigte über lange Zeit die Rolle von Routinen. Das Papier gibt einen Überblick über rezente Forschungen, die sich mit dem Einfluss von Routinen auf Entscheidungen befassen. Es zeigt sich, dass Routinen systematisch die Generierung von Alternativen, die Informationssuche, die Bewertung, die Wahl und schließlich die Implementierung des gewählten Verhaltens beeinflussen. Mit Blick auf die Befunde wird ein breites Rahmenmodell vorgeschlagen, das das Lernen von Routinen als integralen Bestandteil von Entscheidung versteht.
Der Schriftlichkeitsüberlegenheitseffekt:
Authors: Grabowski Joachim
Published: October 2005

Zusammenfassung. Sprachproduktionsprozesse sind an vielen wissensdiagnostischen Verfahren beteiligt, insbesondere in der Prüfungspraxis. Dabei wird die Indikationsbeziehung zwischen dem Gesagten/Geschriebenen und der Wissensgrundlage selten problematisiert. Es wurde untersucht, in welcher Weise die mit dem Sprechen und Schreiben verknüpften Prozesse der Sprachproduktion wissensdiagnostische Resultate systematisch beeinflussen. Insbesondere erwies sich der Schriftlichkeitsüberlegenheitseffekt als stabiler, replizierbarer Befund: Schreiben erlaubt (beim Erwachsenen) inhaltsvalidere Wissensindikationen als Sprechen. Eine theoretische Analyse des mündlichen und schriftlichen Sprachproduktionsprozesses und der kognitiven Belastung spezifischer Teilprozesse lässt erkennen, warum und in welcher Weise Sprachproduktionsresultate kein inhaltsvalides Fenster zur Kognition darstellen. Der wissensdiagnostische Vorteil des Schreibens gegenüber dem Sprechen wird nachgewiesen. In weiteren Experimenten erweisen sich die individuelle Arbeitsgedächtniskapazität sowie die Passung von Input und Output von Wissensbeständen hinsichtlich ihrer verbalen Modalität, nicht aber die allgemeine Intelligenz und das Stresslevel in der diagnostischen Situation als weitere varianzbindende Einflussgrößen des Schriftlichkeitsüberlegenheitseffekts.