bluuebunny/crossref_metadata_2025 huggingface dataset:
Activation of Protein Kinase C Isoforms and Its Impact on Diabetic Complications
Authors: Geraldes Pedro , King George L.
Published: April 2010

Abstract:Both cardio- and microvascular complications adversely affect the life quality of patients with diabetes and have been the leading cause of mortality and morbidity in this population. Cardiovascular pathologies of diabetes have an effect on microvenules, arteries, and myocardium. It is believed that hyperglycemia is one of the most important metabolic factors in the development of both micro- and macrovascular complications in diabetic patients. Several prominent hypotheses exist to explain the adverse effect of hyperglycemia. One of them is the chronic activation by hyperglycemia of protein kinase (PK)C, a family of enzymes that are involved in controlling the function of other proteins. PKC has been associated with vascular alterations such as increases in permeability, contractility, extracellular matrix synthesis, cell growth and apoptosis, angiogenesis, leukocyte adhesion, and cytokine activation and inhibition. These perturbations in vascular cell homeostasis caused by different PKC isoforms (PKC-α, -β1/2, and PKC-δ) are linked to the development of pathologies affecting large vessel (atherosclerosis, cardiomyopathy) and small vessel (retinopathy, nephropathy and neuropathy) complications. Clinical trials using a PKC-β isoform inhibitor have been conducted, with some positive results for diabetic nonproliferative retinopathy, nephropathy, and endothelial dysfunction. This article reviews present understanding of how PKC isoforms cause vascular dysfunctions and pathologies in diabetes.
When whistle-blowing works: The Norwegian case
Authors: Skivenes Marit , Trygstad Sissel C
Published: April 2010

Research on whistle-blowing in the Norwegian public sector shows remarkable findings compared with international research. A very high proportion of employees blow the whistle when they experience misconduct, and the majority of these people receive positive reactions. Furthermore, a majority of the whistle-blowers report that the conduct that led them to blow the whistle improved. These positive findings are different from those reported in international research displaying that whistle-blowing is difficult, often results in retaliation and is rarely effective. This article seeks to shed light on the positive Norwegian experiences, first by exploring how power resources can help us understand the extent and types of whistle-blowing, the consequences for the whistle-blower and the effectiveness of the practice. Second, the article asks whether a Norwegian model of labour relations promotes a communicative ‘culture’ where employees can freely voice their opinions and critical remarks, and report misconduct. The findings show that power resources to a little degree can explain whistle-blowing activity and its results. It is plausible to assume that the strong emphasis on collective arrangements and laws reduces the impact of an individual employee’s power resources by making the reporting process less arbitrary. Furthermore, it could be argued that the Norwegian model establishes structures for a communication culture that facilitates whistle-blowing.
PowerDEVS: a tool for hybrid system modeling and real-time simulation
Authors: Bergero Federico , Kofman Ernesto
Published: April 2010

In this paper we introduce a general-purpose software tool for discrete event system specification (DEVS) modeling and simulation oriented to the simulation of hybrid systems. The environment, called PowerDEVS, allows atomic DEVS models to be defined in C++ language that can then be coupled graphically in hierarchical block diagrams to create more complex systems. The environment automatically translates the graphically coupled models into a C++ code which executes the simulation. A remarkable feature of PowerDEVS is the possibility to perform simulations under a real-time operating system (RTAI) synchronizing with a real-time clock, which permits the design and automatic implementation of synchronous and asynchronous digital controllers. Combined with its continuous system simulation library, PowerDEVS is also an efficient tool for real-time simulation of physical systems. Another feature is the interconnection between PowerDEVS and the numerical package Scilab. PowerDEVS simulations can make use of Scilab workspace variables and functions, and the results can be sent back to Scilab for further processing and data analysis. In addition to describing the main features of the software tool, the article also illustrates its use with some examples which show its simplicity and efficiency.
Informal Lenders and Rural Finance in China: A Report from the Field
Authors: Li Zhou  , Takeuchi Hiroki
Published: April 2010

Chinese farmers need loans. It’s hard for them to borrow from formal lenders like banks or even the rural credit cooperatives. Thus, to satisfy their financial needs, farmers borrow from informal lenders. While farmers have benefited from the post-Mao reform in many respects, financial reforms of the past three decades have failed to create an effective system in which farmers can borrow from formal lenders. To create an effective and efficient financial system that can meet farmers’ needs, it is necessary for informal lenders to play an active role in rural finance. China’s rural finances face four key problems: asymmetric information, a lack of collateral, the unique structure of costs and risks, and the nonproductive use of loans. Informal lenders have an advantage in solving these problems. This article proposes the creation of a financial system in which informal lenders play an active role in lending to farmers and formal and informal lenders cooperate with each other. It develops the argument based on the first author’s field research in the provinces of Guangdong, Henan, Jilin, Shaanxi, Shandong, and Shanxi.
Review: Delivering research in end-of-life care: problems, pitfalls and future priorities
Authors: Bennett Michael I , Davies Elizabeth A , Higginson Irene J
Published: April 2010

In this paper we review the challenges facing the delivery of research in end-of-life care in the UK and internationally as health policies begin to focus on improving care. These include the problems of terminology in this field of enquiry and the lack of emphasis on clinical studies relating to the medical aspects of end-of-life care, including research into pain and other symptoms. Future priorities are discussed that include the pressing need to build research capacity, making better use of existing intelligence, and to progress in incremental steps as part of sustained programmes of research.
Exploring the correspondence between regional forms of governance and regional identity: The case of Western Europe
Authors: Antonsich Marco
Published: April 2010

In the present post-Fordist epoch, the region has emerged as a strategic site for socioeconomic governance. The region today is viewed as a key centre in processes of capital accumulation and (re)production and it occupies an important position in regulating social life. Yet, little is known about the spatial representations held by people about the regions in which they live. This article aims to contribute to fill this gap, by exploring two interrelated issues: what people mean by region and how they relate their sentiment of regional identity to the regional administrative space to which they belong. The study relies on focus group discussions and individual interviews administered in four West European regions. The empirical research suggests that the region is constructed by people as a geographically ambiguous reference and that their sense of regional identity is not necessarily directed towards the region as an administrative space. This challenges the correspondence between function (governance) and identity theorized by the literature on the institutionalization of regions.
Scaphoid kinematics before and after scaphotrapeziotrapezoidal ligament section. Assessment by radiostereometric analysis and computed tomography in a cadaver study
Authors: Stilling M. , Krøner K. , Rømer L. , Van De Giessen M. , Munk B.
Published: April 2010

The purpose of this study was to measure changes in scaphoid kinematics after division of scaphotrapeziotrapezoidal ligaments, with the intention of determining a clinical measure that could be detected by computed tomography. Twelve freshly frozen cadaver upper extremities were marked with tantalum beads and fixed in positions of neutral, 30° extension, and 40° ulnar deviation. Stereoradiographs for bone migration analysis by radiostereometric analysis and computed tomography scans for visible assessment were obtained before and after scaphotrapeziotrapezoidal ligament section. After ligament resection there was a scaphoid supination of 5° and a small (less than 1 mm) radial, distal, and dorsal translation of the distal pole in 30° of wrist extension. In computed tomography reconstructions, the ligament section appeared as a 1 to 2 mm gap in the scaphotrapeziotrapezoidal corner, with loss of articulation between the distal scaphoid pole and the trapezoid bone and increased scaphoid flexion.
Treating Sjögren’s syndrome: insights for the clinician
Authors: Vitali Claudio , Palombi Gianluigi , Cataleta Pierluigi
Published: April 2010

Sjögren’s syndrome (SS) is a systemic autoimmune disease that affects the exocrine glands, mainly the salivary and lachrymal glands, with consequent persistent dryness of the mouth and eyes. In addition to the clinical manifestations related to the exocrine gland involvement, a consistent prevalence of patients may present systemic manifestations. Some of these can be ascribed to the periepithelial extension of lymphocytic infiltration whilst others are determined by an immunomediated process affecting small- or medium-size vessels. While the use of tear and saliva substitutes and local or systemic stimulation of residual secretions represent the mainstays of the therapy of sicca component, different immunomodulating or immunosuppressive agents are usually required to treat extraglandular features, similarly to what happens in other connective tissue diseases. In the last few years, the advancement in the understanding the pathogenetic mechanisms of this disorder and the availability of new biologic target therapies seem to offer completely new therapeutic options. The use of B cell depleting or modulating therapies has achieved promising results.
Advances in the treatment of prediabetes
Authors: Matfin Glenn , Pratley Richard E.
Published: April 2010

Type 2 diabetes mellitus (T2DM) is epidemic in most developed and many developing countries. Owing to the associated morbidity, mortality and high costs of care, T2DM is an important global public health challenge and target for prevention. Patients at high risk for T2DM (referred to as having prediabetes) can be easily identified based on fasting glucose levels or responses to an oral glucose tolerance test (OGTT). More recently, glycosylated hemoglobin (i.e. HbA1c, which is also termed A1C in the US) has also been introduced as a diagnostic tool for both prediabetes and diabetes. Such patients are also at risk for cardiovascular disease (CVD). Since obesity and physical inactivity are important risk factors for T2DM, lifestyle interventions, emphasizing modest weight loss and increases in physical activity, should be recommended for most patients with prediabetes. Such interventions are safe and effective and also reduce risk factors for CVD. A number of oral antidiabetic agents have been shown to be effective at delaying onset of T2DM in patients with prediabetes. Thiazolidinediones (TZDs) are the most effective, reducing incident diabetes by up to 80%. Metformin, acarbose and orlistat also reduce incident diabetes, but their efficacy is much lower than the TZDs. Pharmacologic interventions may be appropriate for patients at particular risk for developing diabetes, but the benefits of treatment need to be balanced against the safety and tolerability of the intervention. If pharmacologic treatment is warranted, metformin should be considered first because of its favorable overall safety, tolerability, efficacy and cost profile.
Therapeutic perspective: starting an angiotensin-converting enzyme inhibitor or angiotensin II receptor blocker in a diabetic patient
Authors: Jarred Ghassan , Lee Kennedy R.
Published: April 2010

There are extensive data confirming involvement of the renin-angiotensin system in microvascular and macrovascular complications of diabetes. Blockade of the system with angiotensin-converting enzyme (ACE) inhibitors or angiotensin II receptor blockers (ARBs) is regarded as the first-line approach to managing hypertension and end-organ protection in patients with diabetes. ACE inhibitors are still the preferred agents for most patients. Dose should be lower with renal impairment unless an agent which is not excreted by the kidneys is chosen. Dose should be titrated up to the maximum tolerated to optimize end-organ protection, and intermediate-acting agents should be given in a twice daily divided dose when higher doses are used. Electrolytes should be checked before commencing, 1-2 weeks later, and after each dose increment. A modest decrease in estimated glomerular filtration rate (eGFR) and increase in creatinine often occurs with ACE inhibitors or ARBs. The agents may need to be discontinued if eGFR decreases by >15%, if creatinine increases by >20%, or if hyperkalaemia develops. Cough occurs in 5-10% of patients taking ACE inhibitor, but not with ARBs. Angioedema is probably equally common with ACE inhibitor or ARBs. It is not widely appreciated that ACE inhibitors may precipitate hypoglycaemia in patients taking glucose-lowering medication. The combination of ACE inhibitor and ARB is not routinely indicated for either hypertension or end-organ protection. While patients should not be denied the undoubted benefits of these important classes of drugs, we should also guard against their indiscriminate use in patients with diabetes. We must also ensure that patients receive appropriate counselling and monitoring.
Genomewide DNA methylation analysis reveals novel targets for drug development in mantle cell lymphoma
Authors: Leshchenko Violetta V. , Kuo Pei-Yu , Shaknovich Rita , Yang David T. , Gellen Tobias , Petrich Adam , Yu Yiting , Remache Yvonne , Weniger Marc A. , Rafiq Sarwish , Suh K. Stephen , Goy Andre , Wilson Wyndham , Verma Amit , Braunschweig Ira , Muthusamy Natarajan , Kahl Brad S. , Byrd John C. , Wiestner Adrian , Melnick Ari , Parekh Samir
Published: April 2010

Mantle cell lymphoma (MCL) is a mostly incurable malignancy arising from naive B cells (NBCs) in the mantle zone of lymph nodes. We analyzed genomewide methylation in MCL patients with the HELP (HpaII tiny fragment Enrichment by Ligation–mediated PCR) assay and found significant aberrancy in promoter methylation patterns compared with normal NBCs. Using biologic and statistical criteria, we further identified 4 hypermethylated genes CDKN2B, MLF-1, PCDH8, and HOXD8 and 4 hypomethylated genes CD37, HDAC1, NOTCH1, and CDK5 when aberrant methylation was associated with inverse changes in mRNA levels. Immunohistochemical analysis of an independent cohort of MCL patient samples confirmed CD37 surface expression in 93% of patients, validating its selection as a target for MCL therapy. Treatment of MCL cell lines with a small modular immunopharmaceutical (CD37-SMIP) resulted in significant loss of viability in cell lines with intense surface CD37 expression. Treatment of MCL cell lines with the DNA methyltransferase inhibitor decitabine resulted in reversal of aberrant hypermethylation and synergized with the histone deacetylase inhibitor suberoylanilide hydroxamic acid in induction of the hypermethylated genes and anti-MCL cytotoxicity. Our data show prominent and aberrant promoter methylation in MCL and suggest that differentially methylated genes can be targeted for therapeutic benefit in MCL.
Ferrochelatase forms an oligomeric complex with mitoferrin-1 and Abcb10 for erythroid heme biosynthesis
Authors: Chen Wen , Dailey Harry A. , Paw Barry H.
Published: April 2010

In erythroid cells, ferrous iron is imported into the mitochondrion by mitoferrin-1 (Mfrn1). Previously, we showed that Mfrn1 interacts with Abcb10 to enhance mitochondrial iron importation. Herein we have derived stable Friend mouse erythroleukemia (MEL) cell clones expressing either Mfrn1-FLAG or Abcb10-FLAG and by affinity purification and mass spectrometry have identified ferrochelatase (Fech) as an interacting protein for both Mfrn1 and Abcb10. Fech is the terminal heme synthesis enzyme to catalyze the insertion of the imported iron into protoporphyrin IX to produce heme. The Mfrn1-Fech and Abcb10-Fech interactions were confirmed by immunoprecipitation/Western blot analysis with endogenous proteins in MEL cells and heterologous proteins expressed in HEK293 cells. Moreover, Fech protein is induced in parallel with Mfrn1 and Abcb10 during MEL cell erythroid differentiation. Our findings imply that Fech forms an oligomeric complex with Mfrn1 and Abcb10 to synergistically integrate mitochondrial iron importation and use for heme biosynthesis.
GATExplorer: Genomic and Transcriptomic Explorer; mapping expression probes to gene loci, transcripts, exons and ncRNAs
Authors: Risueño Alberto , Fontanillo Celia , Dinger Marcel E , De Las Rivas Javier
Published: April 2010

Background

Genome-wide expression studies have developed exponentially in recent years as a result of extensive use of microarray technology. However, expression signals are typically calculated using the assignment of "probesets" to genes, without addressing the problem of "gene" definition or proper consideration of the location of the measuring probes in the context of the currently known genomes and transcriptomes. Moreover, as our knowledge of metazoan genomes improves, the number of both protein-coding and noncoding genes, as well as their associated isoforms, continues to increase. Consequently, there is a need for new databases that combine genomic and transcriptomic information and provide updated mapping of expression probes to current genomic annotations.

Results

GATExplorer (Genomic and Transcriptomic Explorer) is a database and web platform that integrates a gene loci browser with nucleotide level mappings of oligo probes from expression microarrays. It allows interactive exploration of gene loci, transcripts and exons of human, mouse and rat genomes, and shows the specific location of all mappable Affymetrix microarray probes and their respective expression levels in a broad set of biological samples. The web site allows visualization of probes in their genomic context together with any associated protein-coding or noncoding transcripts. In the case of all-exon arrays, this provides a means by which the expression of the individual exons within a gene can be compared, thereby facilitating the identification and analysis of alternatively spliced exons. The application integrates data from four major source databases: Ensembl, RNAdb, Affymetrix and GeneAtlas; and it provides the users with a series of files and packages (R CDFs) to analyze particular query expression datasets. The maps cover both the widely used Affymetrix GeneChip microarrays based on 3' expression (e.g. human HG U133 series) and the all-exon expression microarrays (Gene 1.0 and Exon 1.0).

Conclusions

GATExplorer is an integrated database that combines genomic/transcriptomic visualization with nucleotide-level probe mapping. By considering expression at the nucleotide level rather than the gene level, it shows that the arrays detect expression signals from entities that most researchers do not contemplate or discriminate. This approach provides the means to undertake a higher resolution analysis of microarray data and potentially extract considerably more detailed and biologically accurate information from existing and future microarray experiments.
A mutation in the cytosolic O-acetylserine (thiol) lyase induces a genome-dependent early leaf death phenotype in Arabidopsis
Authors: Shirzadian-Khorramabad Reza , Jing Hai-Chun , Everts Gerja E , Schippers Jos HM , Hille Jacques , Dijkwel Paul P
Published: April 2010

Background

Cysteine is a component in organic compounds including glutathione that have been implicated in the adaptation of plants to stresses. O-acetylserine (thiol) lyase (OAS-TL) catalyses the final step of cysteine biosynthesis. OAS-TL enzyme isoforms are localised in the cytoplasm, the plastids and mitochondria but the contribution of individual OAS-TL isoforms to plant sulphur metabolism has not yet been fully clarified.

Results

The seedling lethal phenotype of the Arabidopsis onset of leaf death3-1 (old3-1) mutant is due to a point mutation in the OAS-A1 gene, encoding the cytosolic OAS-TL. The mutation causes a single amino acid substitution from Gly162 to Glu162, abolishing old3-1 OAS-TL activity in vitro. The old3-1 mutation segregates as a monogenic semi-dominant trait when backcrossed to its wild type accession Landsberg erecta (Ler-0) and the Di-2 accession. Consistent with its semi-dominant behaviour, wild type Ler-0 plants transformed with the mutated old3-1 gene, displayed the early leaf death phenotype. However, the old3-1 mutation segregates in an 11:4:1 (wild type: semi-dominant: mutant) ratio when backcrossed to the Colombia-0 and Wassilewskija accessions. Thus, the early leaf death phenotype depends on two semi-dominant loci. The second locus that determines the old3-1 early leaf death phenotype is referred to as odd-ler (for
o

l

d

3
determinant in the Ler accession) and is located on chromosome 3. The early leaf death phenotype is temperature dependent and is associated with increased expression of defence-response and oxidative-stress marker genes. Independent of the presence of the odd-ler gene, OAS-A1 is involved in maintaining sulphur and thiol levels and is required for resistance against cadmium stress.

Conclusions

The cytosolic OAS-TL is involved in maintaining organic sulphur levels. The old3-1 mutation causes genome-dependent and independent phenotypes and uncovers a novel function for the mutated OAS-TL in cell death regulation.
The chemotherapeutic agent bortezomib induces the formation of stress granules
Authors: Fournier Marie-Josée , Gareau Cristina , Mazroui Rachid
Published: April 2010

Background

Cytoplasmic stress granules (SGs) are specialized storage sites of untranslated mRNAs whose formation occurs under different stress conditions and is often associated with cell survival. SGs-inducing stresses include radiations, hypoxia, viral infections, and chemical inhibitors of specific translation initiation factors. The FDA-approved drug bortezomib (Velcade®) is a peptide boronate inhibitor of the 26S proteasome that is very efficient for the treatment of myelomas and other hematological tumors. Solid tumors are largely refractory to bortezomib. In the present study, we investigated the formation of SGs following bortezomib treatment.

Results

We show that bortezomib efficiently induces the formation of SGs in cancer cells. This process involves the phosphorylation of translation initiation factor eIF2α by heme-regulated inhibitor kinase (HRI). Depletion of HRI prevents bortezomib-induced formation of SGs and promotes apoptosis.

Conclusions

This is the first study describing the formation of SGs by a chemotherapeutic compound. We speculate that the activation of HRI and the formation of SGs might constitute a mechanism by which cancer cells resist bortezomib-mediated apoptosis.
Application of magnetic resonance imaging in transgenic and chemical mouse models of hepatocellular carcinoma
Authors: Freimuth Julia , Gassler Nikolaus , Moro Nives , Günther Rolf W. , Trautwein Christian , Liedtke Christian , Krombach Gabriele A.
Published: April 2010

Background

Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide. The molecular mechanisms underlying hepatocarcinogenesis are still poorly understood. Genetically modified mice are powerful tools to further investigate the mechanisms of HCC development. However, this approach is limited due to the lack of non-invasive detection methods in small rodents. The aim of this study was to establish a protocol for the non-invasive analysis of hepatocarcinogenesis in transgenic mice using a clinical 1.5 Tesla Magnetic Resonance Imaging scanner.

Results

As a model system we used hepatocyte-specific c-myc transgenic mice developing hepatocellular carcinoma at the age of 12-15 months. The scans of the murine livers included axial T2-weighted turbo-spin echo (TSE) images, axial T1-weighted and contrast enhanced T1-weighted gradient echo (fast field echo, FFE) and sagittal true Fast Imaging with Steady state Precession (true-FISP) images. Application of contrast agent was performed via tail vein-catheter and confirmed by evaluation of the altered longitudinal relaxation T1 time before and after application. Through technical adaptation and optimization we could detect murine liver lesions with a minimum diameter of approximately 2 mm and provided histopathological evidence that these MR findings correspond to hepatocellular carcinoma. Tumor growth was repeatedly measured using sequential MRI with intervals of 5 weeks and subsequent volumetric analysis facilitating direct comparison of tumor progression between individual animals. We finally demonstrated that our protocol is also applicable in the widely- used chemical model of N-nitrosodiethylamine-induced hepatocarcinogenesis.

Conclusion

Our protocol allows the non-invasive, early detection of HCC and the subsequent continuous monitoring of liver tumorgenesis in transgenic mice thereby facilitating future investigations of transgenic tumor mouse models of the liver.
ISG20L1 is a p53 family target gene that modulates genotoxic stress-induced autophagy
Authors: Eby Kathryn G. , Rosenbluth Jennifer M. , Mays Deborah J. , Marshall Clayton B. , Barton Christopher E. , Sinha Seema , Johnson Kimberly N. , Tang Luojia , Pietenpol Jennifer A.
Published: April 2010

Background

Autophagy is characterized by the sequestration of cytoplasm and organelles into multimembrane vesicles and subsequent degradation by the cell's lysosomal system. It is linked to many physiological functions in human cells including stress response, protein degradation, organelle turnover, caspase-independent cell death and tumor suppression. Malignant transformation is frequently associated with deregulation of autophagy and several tumor suppressors can modulate autophagic processes. The tumor suppressor p53 can induce autophagy after metabolic or genotoxic stress through transcriptionally-dependent and -independent mechanisms. In this study we expand on the former mechanism by functionally characterizing a p53 family target gene, ISG20L1 under conditions of genotoxic stress.

Results

We identified a p53 target gene, ISG20L1, and show that transcription of the gene can be regulated by all three p53 family members (p53, p63, and p73). We generated an antibody to ISG20L1 and found that it localizes to the nucleolar and perinucleolar regions of the nucleus and its protein levels increase in a p53- and p73-dependent manner after various forms of genotoxic stress. When ectopically expressed in epithelial cancer-derived cell lines, ISG20L1 expression decreased clonogenic survival without a concomitant elevation in apoptosis and this effect was partially rescued in cells that were ATG5 deficient. Knockdown of ISG20L1 did not alter 5-FU induced apoptosis as assessed by PARP and caspase-3 cleavage, sub-G1 content, and DNA laddering. Thus, we investigated the role of ISG20L1 in autophagy, a process commonly associated with type II cell death, and found that ISG20L1 knockdown decreased levels of autophagic vacuoles and LC3-II after genotoxic stress as assessed by electron microscopy, biochemical, and immunohistochemical measurements of LC3-II.

Conclusions

Our identification of ISG20L1 as a p53 family target and discovery that modulation of this target can regulate autophagic processes further strengthens the connection between p53 signaling and autophagy. Given the keen interest in targeting autophagy as an anticancer therapeutic approach in tumor cells that are defective in apoptosis, investigation of genes and signaling pathways involved in cell death associated with autophagy is critical.
Three agonist antibodies in combination with high-dose IL-2 eradicate orthotopic kidney cancer in mice
Authors: Westwood Jennifer A , Darcy Phillip K , Guru Preethi Mayura , Sharkey Janelle , Pegram Hollie J , Amos Sally M , Smyth Mark J , Kershaw Michael H
Published: April 2010

Background

Combination immunotherapies can be effective against subcutaneous tumors in mice but the effect against orthotopic malignant disease is less well characterized. In particular, a combination of three agonist antibodies, termed Tri-mAb, consisting of anti-DR5, anti-CD40 and anti-CD137 has previously been demonstrated to eradicate a large proportion of subcutaneous renal cell carcinoma (Renca) tumors (75% long-term survival), but the effect against orthotopic disease is not known.

Purpose

To determine the relative response of orthotopic tumors, we inoculated Renca into the kidney followed by treatment with Tri-mAb.

Results

We found that orthotopic tumors responded much less to treatment (~13% survival), but a significant improvement in survival was achieved through the addition of IL-2 to the treatment regimen (55% survival). All three agonist antibodies and high dose IL-2, 100,000 IU for up to six doses, were required. CD8+T cells were also required for optimal anti-tumor responses. Coadministration of IL-2 led to enhanced T cell activity as demonstrated by an increased frequency of IFN-gamma-producing T cells in tumor-draining lymph nodes, which may have contributed to the observed improvement of therapy against kidney tumors.

Implications

Responses of subcutaneous tumors to immunotherapy do not necessarily reflect how orthotopic tumors respond. The use of combination immunotherapy stimulating multiple facets of immunity and including cytokine support for T cells can induce effective anti-tumor responses against orthotopic and metastatic tumors.
Transcriptional regulation of matrix metalloproteinase-1 and collagen 1A2 explains the anti-fibrotic effect exerted by proteasome inhibition in human dermal fibroblasts
Authors: Goffin Laurence , Seguin-Estévez Queralt , Alvarez Montserrat , Reith Walter , Chizzolini Carlo
Published: April 2010

Introduction

Extracellular matrix (ECM) turnover is controlled by the synthetic rate of matrix proteins, including type I collagen, and their enzymatic degradation by matrix metalloproteinases (MMPs). Fibrosis is characterized by an unbalanced accumulation of ECM leading to organ dysfunction as observed in systemic sclerosis. We previously reported that proteasome inhibition (PI) in vitro decreases type I collagen and enhances MMP-1 production by human fibroblasts, thus favoring an antifibrotic fibroblast phenotype. These effects were dominant over the pro-fibrotic phenotype induced by transforming growth factor (TGF)-β. Here we investigate the molecular events responsible for the anti-fibrotic phenotype induced in fibroblasts by the proteasome inhibitor bortezomib.

Methods

The steady-state mRNA levels of COL1A1, COL1A2, TIMP-1, MMP-1, and MMP-2 were assessed by quantitative PCR in human dermal fibroblasts cultured in the presence of TGF-β, bortezomib, or both. Transient fibroblast transfection was performed with wild-type and mutated COL1A1 and MMP-1 promoters. Chromatin immunoprecipitation, electrophoretic mobility shift assay (EMSA), and DNA pull-down assays were used to assess the binding of c-Jun, SP1, AP2, and Smad2 transcription factors. Immunoblotting and immunofluorescent microscopy were performed for identifying phosphorylated transcription factors and their cellular localization.

Results

Bortezomib decreased the steady-state mRNA levels of COL1A1 and COL1A2, and abrogated SP1 binding to the promoter of COL1A2 in both untreated and TGF-β-activated fibroblasts. Reduced COL1A2 expression was not due to altered TGF-β-induced Smad2 phosphorylation, nuclear translocation, or binding to the COL1A2 promoter. In contrast to collagen, bortezomib specifically increased the steady-state mRNA levels of MMP-1 and enhanced the binding of c-Jun to the promoter of MMP-1. Furthermore, disruption of the proximal AP-1-binding site in the promoter of MMP-1 severely impaired MMP-1 transcription in response to bortezomib.

Conclusions

By altering the binding of at least two transcription factors, c-Jun and SP1, proteasome inhibition results in increased production of MMP-1 and decreased synthesis of type I collagen in human dermal fibroblasts. Thus, the antifibrotic phenotype observed in fibroblasts submitted to proteasome inhibition results from profound modifications in the binding of key transcription factors. This provides a novel rationale for assessing the potential of drugs targeting the proteasome for their anti-fibrotic properties.
Early fiberoptic bronchoscopy during non-invasive ventilation in patients with decompensated chronic obstructive pulmonary disease due to community-acquired-pneumonia
Authors: Scala Raffaele , Naldi Mario , Maccari Uberto
Published: April 2010

Introduction

Inefficient clearance of copious respiratory secretion is a cause of non-invasive positive pressure ventilation (NPPV) failure, especially in chronic respiratory patients with community-acquired-pneumonia (CAP) and impaired consciousness. We postulated that in such a clinical scenario, when intubation and conventional mechanical ventilation (CMV) are strongly recommended, the suction of secretions with fiberoptic bronchoscopy (FBO) may increase the chance of NPPV success. The objective of this pilot study was, firstly, to verify the safety and effectiveness of early FBO during NPPV and, secondly, to compare the hospital outcomes of this strategy versus a CMV-based strategy in patients with decompensated chronic obstructive pulmonary disease (COPD) due to CAP who are not appropriate candidates for NPPV because of inefficient mucous clearance and hypercapnic encephalopathy (HE).

Methods

This is a 12-month prospective matched case-control study performed in one respiratory semi-intensive care unit (RSICU) with expertise in NPPV and in one intensive care unit (ICU). Fifteen acutely decompensated COPD patients with copious secretion retention and HE due to CAP undergoing NPPV in RSICU, and 15 controls (matched for arterial blood gases, acute physiology and chronic health evaluation score III, Kelly-Matthay scale, pneumonia extension and severity) receiving CMV in the ICU were studied.

Results

Two hours of NPPV significantly improved arterial blood gases, Kelly and cough efficiency scores without FBO-related complications. NPPV avoided intubation in 12/15 patients (80%). Improvement in arterial blood gases was similar in the two groups, except for a greater PaO2/fraction of inspired oxygen ratio with CMV. The rates of overall and septic complications, and of tracheostomy were lower in the NPPV group (20%, 20%, and 0%) versus the CMV group (80%, 60%, and 40%; P < 0.05). Hospital mortality, duration of hospitalisation and duration of ventilation were similar in the two groups.

Conclusions

In patients with decompensated COPD due to CAP who are candidates for CMV because of HE and inability to clear copious secretions, NPPV with early therapeutic FBO performed by an experienced team is a feasible, safe and effective alternative strategy.
Editorial: CSF1R, CSF-1, and IL-34, a “ménage à trois” conserved across vertebrates
Authors: Droin Nathalie , Solary Eric
Published: April 2010

Editorial discusses the perspectives opened by the recently discovered IL-34, its conservation across species in the biology of the cytokine CSF-1, and identification of a new CSF-1R ligand that could together account for the well-known heterogeneity of monocytes.
Regulation of Adipogenesis by Natural and Synthetic REV-ERB Ligands
Authors: Kumar Naresh , Solt Laura A. , Wang Yongjun , Rogers Pamela M. , Bhattacharyya Gargi , Kamenecka Theodore M. , Stayrook Keith R. , Crumbley Christine , Floyd Z. Elizabeth , Gimble Jeffrey M. , Griffin Patrick R. , Burris Thomas P.
Published: April 2010

The nuclear hormone receptor, REV-ERB, plays an essential role in adipogenesis. Rev-erbα expression is induced in 3T3-L1 cells during adipogenesis, and overexpression of this receptor leads to expression of adipogenic genes. We recently demonstrated that the porphyrin heme functions as a ligand for REV-ERB, and binding of heme is required for the receptor’s activity. We therefore hypothesized that REV-ERB ligands may play a role in regulation of adipogenesis. We detected an increase intracellular heme levels during 3T3-L1 adipogenesis that correlated with induction of aminolevulinic acid synthase 1 (Alas1) expression, the rate-limiting enzyme in heme biosynthesis. If the increase in Alas1 expression was blocked, adipogenesis was severely attenuated, indicating that induction of expression of Alas1 and the increase in heme synthesis is critical for differentiation. Inhibition of heme synthesis during adipogenesis leads to decreased recruitment of nuclear receptor corepressor to the promoter of a REV-ERB target gene, suggesting alteration of REV-ERB activity. Treatment of 3T3-L1 cells with a synthetic REV-ERB ligand, SR6452, resulted in induction of adipocyte differentiation to a similar extent as treatment with the peroxisomal proliferator-activated receptor-γ agonist, rosiglitazone. Combination of SR6452 and rosiglitazone had an additive effect on stimulation of adipocyte differentiation. These results suggest that heme, functioning as a REV-ERB ligand, is an important signaling molecule for induction of adipogenesis. Moreover, synthetic small molecule ligands for REV-ERB are effective modulators of adipogenesis and may be useful for treatment of metabolic diseases.
Troglitazone, a Ligand of Peroxisome Proliferator-Activated Receptor-γ, Stabilizes NUCB2 (Nesfatin) mRNA by Activating the ERK1/2 Pathway: Isolation and Characterization of the Human NUCB2 Gene
Authors: Yamada Masanobu , Horiguchi Kazuhiko , Umezawa Ryohei , Hashimoto Koshi , Satoh Tetsurou , Ozawa Atsushi , Shibusawa Nobuyuki , Monden Tsuyoshi , Okada Shuichi , Shimizu Hiroyuki , Mori Masatomo
Published: April 2010

We recently identified a novel satiety peptide, nesfatin-1, containing 82 amino acids derived from the precursor peptide, nucleobindin 2 (NUCB2), from a troglitazone (TZ)-induced cDNA library. We examined the molecular mechanism underlying TZ-induced NUCB2 mRNA expression. Although TZ induced the mRNA expression in HTB185 cells, a nuclear run-on assay revealed no significant change in the transcription of the gene. Surprisingly, HTB185 cells possessed no functional peroxisome proliferator-activated receptor-γ. We therefore examined the effect of TZ on the mRNA’s stability. The half-life of NUCB2 mRNA was approximately 6 h, and incubation with TZ increased this to 27 h. Furthermore, this increase was completely inhibited by an ERK inhibitor, PD98059, and phosphorylated ERK1/2 was significantly increased after 30 min incubation with TZ. In addition, we cloned the entire NUCB2 gene and identified four adenylate/uridylate-rich elements (AREs) in the 3′ untranslated region (UTR), to which several proteins of HTB185 extracts treated with TZ bound. The reporter assay fused with 3′UTR showed that the second and third AREs were crucial. Furthermore, the human NUCB2 gene spanned 55 kb and contained 14 exons and 13 introns. The transcriptional start site formed clusters around 246 bp upstream from the translational start site. We confirmed that a construct containing 5889 bp of the promoter region was very active in neuron-derived cell lines but not stimulated by TZ. These findings demonstrated a novel action of derivatives of thiazolidinediones, oral insulin-sensitizing antidiabetic agents, to stabilize the mRNA of NUCB2 through AREs in the 3′UTR by activating the ERK1/2 pathway independently of peroxisome proliferator-activated receptor-γ.
SNX18 shares a redundant role with SNX9 and modulates endocytic trafficking at the plasma membrane
Authors: Park Joohyun , Kim Yoonju , Lee Suho , Park Jae Jun , Park Zee Yong , Sun Woong , Kim Hyun , Chang Sunghoe
Published: April 2010

SNX18 and SNX9 are members of a subfamily of SNX (sorting nexin) proteins with the same domain structure. Although a recent report showed that SNX18 and SNX9 localize differently in cells and appear to function in different trafficking pathways, concrete evidence regarding whether they act together or separately in intracellular trafficking is still lacking. Here, we show that SNX18 has a similar role to SNX9 in endocytic trafficking at the plasma membrane, rather than having a distinct role. SNX18 and SNX9 are expressed together in most cell lines, but to a different extent. Like SNX9, SNX18 interacts with dynamin and stimulates the basal GTPase activity of dynamin. It also interacts with neuronal Wiskott-Aldrich syndrome protein (N-WASP) and synaptojanin, as does SNX9. SNX18 and SNX9 can form a heterodimer and colocalize in tubular membrane structures. Depletion of SNX18 by small hairpin RNA inhibited transferrin uptake. SNX18 successfully compensates for SNX9 deficiency during clathrin-mediated endocytosis and vice versa. Total internal reflection fluorescence microscopy in living cells shows that a transient burst of SNX18 recruitment to clathrin-coated pits coincides spatiotemporally with a burst of dynamin and SNX9. Taken together, our results suggest that SNX18 functions with SNX9 in multiple pathways of endocytosis at the plasma membrane and that they are functionally redundant.
Development of a PC-based control system for a five-axis ultraprecision micromilling machine ‘Ultra-Mill’ and its performance assessment
Authors: Nor M K M , Cheng K
Published: April 2010

In the realm of micro- and nanomachining, high-precision three-dimensional miniaturized components and microstructures from an extensive range of engineering materials are increasingly required in industries such as optics, automotive, medical, aerospace, and defence. Five-axis ultraprecision micromilling machines are essential for manufacturing components and microstructures for these industries. This paper presents the design and development of the control system for a five-axis ultraprecision micromillling machine – Ultra-Mill – and its performance assessment based on two application case studies. The design specifications of Ultra-Mill are based on motion and positioning accuracy, dynamic stiffness, thermal stability, and online monitoring and inspection requirements, which are heavily dependent on the control system for the micromilling machine and associated micromilling processes. The implementation and application perspectives of the control system are therefore presented in relation to the ultraprecision and micro/nano feature capability of the machine and process, including controller dynamics, driver and actuation dynamics, feedback dynamics, online inspection and monitoring, and software dynamics.
Transient Natural Convection Flow between Vertical Parallel Plates: One Plate Isothermally Heated and the Other Thermally Insulated
Authors: Jha B K , Ajibade A O
Published: April 2010

This paper presents transient motion of a viscous and incompressible fluid between two infinite vertical parallel plates due to natural convection currents occurring as a result of application of isothermal and adiabatic conditions on the plates. The method of Laplace transform is used to solve the problem. During the course of computation, an excellent agreement was found between the well known steady-state solutions and transient solutions at large value of time.
Mathematical modelling and experimental characterization of a high dynamic servo valve integrated with piezoelectric actuator
Authors: Karunanidhi S , Singaperumal M
Published: April 2010

A conventional two-stage servo valve basically consists of an electrically operated torque motor as the first stage and spool valve as the second stage. Owing to the limitation in the band width, servo valves are not suitable for high-frequency applications. The work presented in this paper deals with the methodology of the mechatronics approach for the design of a piezoelectric actuator with a mechanical amplifier and its integration into a servo valve. The analysis and simulation of a multilayer piezoelectric actuator (MLA) a with mechanical amplifier for high-frequency application has been done using icon-based bond graph technique and finite element coupled field analysis for the commercially available piezoelectric actuator. The designed piezoelectric actuator was integrated into an existing flapper-nozzle servo valve by replacing the first stage. The dynamics of the valve integrated into a piezoelectric actuator has been simulated. The required simulation parameters for the actuator have been derived from a finite element model. An experimental set-up has been designed and the integrated testing of the servo valve with piezoelectric actuator has been carried out to determine the no-load flow gain of the valve. Also the time response has been measured for a conventional servo valve and servo valve with piezoelectric actuator. The designed valve with a piezoelectric actuator has satisfactory static and dynamic characteristics for high-speed applications.
Stability criteria for neutral uncertain systems with time-varying delays
Authors: Liu P-L
Published: April 2010

This paper is concerned with the delay-dependent robust stability problem for uncertain linear systems with time-varying delays. In order to establish a new delay-dependent criterion for asymptotic stability and robust stability of the systems, a Lyapunov-Krasovskii functional coupled with the Leibniz-Newton formula and an integral inequality approach are introduced to express the relationship between system states and their derivatives. The sufficient stability condition with delay dependence is obtained in terms of a linear matrix inequality (LMI). The LMI can be easily solved using convex optimization algorithms. Two examples are given to illustrate the advantages of the proposed method.
Numerical simulation of combustion-driven oil transport on the top land of an internal combustion engine piston
Authors: McGrogan S , Tian T
Published: April 2010

A mathematical model of a lubricant film attached to the top land of an internal combustion engine piston was formulated. Multidimensional oil transport induced by gas flows within the top land crevice was included in the model, with the intention of predicting the effects of such gas flows on top land carbon deposits. A finite-volume, shock-capturing simulation of the film's free surface was created, and its accuracy verified. Preliminary results were generated using crevice gas flow data taken from a separate computational fluid dynamics (CFD) simulation of a modern diesel engine's combustion process.

It was found that combustion-driven gas flows within the top land crevice can have a profound effect on the top land oil film thickness distribution. A fundamental lubricant transport mechanism arising from an interaction between the effects of the engine's reciprocating inertia and those of the gas flow-induced shear forces was discovered. For the engine studied in the present work, the mechanism severely reduced the amount of lubricant in some regions of the top land. An engine designe's clever usage of this mechanism could potentially reduce both oil consumption and top land carbon deposits.