bluuebunny/crossref_metadata_2025 huggingface dataset:
Role of apoptotic and matrix‐degrading genes in articular cartilage and meniscus of mature and aged rabbits during development of osteoarthritis
Authors: Pennock Andrew T. , Robertson Catherine M. , Emmerson Bryan C. , Harwood Frederick L. , Amiel David
Published: April 2007

Objective

To determine expression patterns of apoptotic and matrix‐degrading genes during aging and development of osteoarthritis (OA), using a rabbit model of induced OA.

Methods

Six mature and 6 aged rabbits underwent anterior cruciate ligament transection and were killed 4 and 8 weeks after surgery, respectively, to create early‐grade and advanced‐grade OA. RNA from articular cartilage and menisci was examined for expression of the genes caspase 8, Fas, Fas ligand, p53, aggrecanase, matrix metalloproteinase 1 (MMP‐1), and MMP‐3. A second cohort of animals that had undergone no intervention in the joint was also killed. Parametric data were analyzed with analysis of variance and Student'st‐tests, while nonparametric data were assessed with the Mann‐Whitney U test.

Results

Expression levels of Fas, caspase 8, FasL, and MMP‐1 were significantly higher (>100%) in aged cartilage compared with mature cartilage (P< 0.05). After induction of OA, expression of apoptotic genes in aged rabbits remained high, while significant up‐regulation of Fas and caspase 8 (nearly 150% increase) was observed in mature rabbits (P< 0.05). No significant up‐regulation of these genes was observed in the menisci of aged or mature rabbits prior to or after induction of OA. Development of OA occurred more rapidly in aged cartilage compared with mature cartilage (P< 0.05).

Conclusion

Differential expression of apoptotic and matrix‐degrading genes occurs in aged compared with mature cartilage, both at baseline and during development of OA. This may be responsible for faster degradation of aged cartilage and its predisposition for developing OA.
Efficacy of methotrexate treatment in patients with probable rheumatoid arthritis: A double‐blind, randomized, placebo‐controlled trial
Authors: van Dongen Henrike , van Aken Jill , Lard Leroy R. , Visser Karen , Ronday H. Karel , Hulsmans Harry M. J. , Speyer Irene , Westedt Marie‐Louise , Peeters André J. , Allaart Cornelia F. , Toes René E. M. , Breedveld Ferdinand C. , Huizinga Tom W. J.
Published: April 2007

Objective

To determine whether patients with undifferentiated arthritis (UA; inflammatory, nontraumatic arthritis that cannot be diagnosed using current classification criteria) benefit from treatment with methotrexate (MTX).

Methods

The PRObable rheumatoid arthritis: Methotrexate versus Placebo Treatment (PROMPT) study was a double‐blind, placebo‐controlled, randomized, multicenter trial involving 110 patients with UA who fulfilled the American College of Rheumatology (ACR) 1958 criteria for probable RA. Treatment started with MTX (15 mg/week) or placebo tablets, and every 3 months the dosage was increased if the Disease Activity Score was >2.4. After 12 months, the study medication was tapered and discontinued. Patients were followed up for 30 months. When a patient fulfilled the ACR criteria for RA (primary end point), the study medication was changed to MTX. Joint damage was scored on radiographs of the hands and feet.

Results

In 22 of the 55 patients (40%) in the MTX group, UA progressed to RA compared with 29 of 55 patients (53%) in the placebo group. However, in the MTX group, patients fulfilled the ACR criteria for RA at a later time point than in the placebo group (P = 0.04), and fewer patients showed radiographic progression over 18 months (P = 0.046).

Conclusion

This study provides evidence for the efficacy of MTX treatment in postponing the diagnosis of RA, as defined by the ACR 1987 criteria, and retarding radiographic joint damage in UA patients.
Longitudinal performance evaluation and validation of fixed‐flexion radiography of the knee for detection of joint space loss
Authors: Nevitt Michael C. , Peterfy Charles , Guermazi Ali , Felson David T. , Duryea Jeff , Woodworth Thasia , Chen Hepei , Kwoh Kent , Harris Tamara B.
Published: April 2007

Objective

The ability of nonfluoroscopically guided radiography of the knee to assess joint space loss is an important issue in studies of progression and treatment of knee osteoarthritis (OA), given the practical limitations of protocols involving fluoroscopically guided radiography of the knee. We evaluated the ability of the nonfluoroscopically guided fixed‐flexion radiography protocol to detect knee joint space loss over 3 years.

Methods

We assessed the same‐day test–retest precision for measuring minimum joint space width (JSW), the sensitivity for detection of joint space loss using serial films obtained a median of 37 months (range 23–47 months) apart, and the relationship of joint space loss to radiographic and magnetic resonance imaging (MRI) measures of knee OA. Participants were men and women (ages 70–79 years) with knee pain who were participating in the Health, Aging, and Body Composition Study. We assessed baseline radiographic OA and measured JSW using a computerized algorithm. Serial knee MRIs obtained over the same interval were evaluated for cartilage lesions.

Results

A total of 153 knees were studied, 35% of which had radiographic OA at baseline. The mean ± SD joint space loss for all knees over 3 years was 0.24 ± 0.59 mm (P < 0.001 for change). In knees with OA at baseline, the mean ± SD joint space loss over 3 years was 0.43 ± 0.66 mm (P < 0.001), and in knees with joint space narrowing at baseline, joint space loss was 0.50 ± 0.67 mm (P < 0.001). Joint space loss and its standardized response mean increased with the severity of baseline joint space narrowing and with the presence of cartilage lesions at baseline and worsening during followup.

Conclusion

Radiography of the knee in the fixed‐flexion view provides a sensitive and valid measure of joint space loss in multiyear longitudinal studies of knee OA, without the use of fluoroscopy to aid knee positioning.
Medical care expenditures and earnings losses among persons with arthritis and other rheumatic conditions in 2003, and comparisons with 1997
Authors: Yelin Edward , Murphy Louise , Cisternas Miriam G. , Foreman Aimee J. , Pasta David J. , Helmick Charles G.
Published: April 2007

Objective

To obtain estimates of medical care expenditures and earnings losses associated with arthritis and other rheumatic conditions and the increment in such costs attributable to arthritis and other rheumatic conditions in the US in 2003, and to compare these estimates with those from 1997.

Methods

Estimates for 2003 were derived from the Medical Expenditures Panel Survey (MEPS), a national probability sample of households. We tabulated medical care expenditures of adult MEPS respondents, stratified by arthritis and comorbidity status, and used regression techniques to estimate the increment of medical care expenditures attributable to arthritis and other rheumatic conditions. We also estimated the earnings losses sustained by working‐age adults with arthritis and other rheumatic conditions. Estimates for 2003 were compared with those from 1997, inflated to 2003 terms.

Results

In 2003, there were 46.1 million adults with arthritis and other rheumatic conditions (versus 36.8 million in 1997). Adults with arthritis and other rheumatic conditions incurred mean medical care expenditures of $6,978 in 2003 (versus $6,346 in 1997), of which $1,635 was for prescriptions ($899 in 1997). Expenditures for adults with arthritis and other rheumatic conditions totaled $321.8 billion in 2003 ($233.5 billion in 1997). In 2003, the mean increment in medical care expenditures attributable to arthritis and other rheumatic conditions was $1,752 ($1,762 in 1997), for a total of $80.8 billion ($64.8 billion in 1997). Persons with arthritis and other rheumatic conditions ages 18–64 years earned $3,613 less than other persons (versus $4,551 in 1997), for a total of $108.0 billion (versus $99.0 billion). Of this amount, $1,590 was attributable to arthritis and other rheumatic conditions (versus $1,946 in 1997), for a total of $47.0 billion ($43.3 billion in 1997).

Conclusion

Our findings indicate that the increase in medical care expenditures and earnings losses between 1997 and 2003 is due more to an increase in the number of persons with arthritis and other rheumatic conditions than to costs per case.
Alteration of antigen‐independent immunologic synapse formation between dendritic cells from HLA–B27–transgenic rats and CD4+ T cells: Selective impairment of costimulatory molecule engagement by mature HLA–B27
Authors: Hacquard‐Bouder Cécile , Chimenti Maria‐Sole , Giquel Benoît , Donnadieu Emmanuel , Fert Ingrid , Schmitt Alain , André Claudine , Breban Maxime
Published: April 2007

Objective

To investigate the molecular mechanism responsible for the reduced capacity of dendritic cells (DCs) from HLA–B27–transgenic rats to form conjugates with naive T cells.

Methods

We monitored interactions between DCs derived from HLA–B27–transgenic, HLA–B7–transgenic control, and nontransgenic rats and naive CD4+ T cells. Chemoattraction was studied in Transwell assays, and the formation of an immunologic synapse was examined by videomicroscopy and electron microscopy. Involvement of specific molecules in the defective interaction was examined in antibody‐blocking assays.

Results

T cells migrated normally toward B27 DCs, but upon contact, the frequency of T cells undergoing a Ca2+response was decreased, indicating impaired immunologic synapse formation. The immunologic synapse formed between B27 DCs and T cells appeared to be normal, as assessed by electron microscopy and by the Ca2+response. Blocking lymphocyte function−associated antigen 1 on T cells or blocking activated leukocyte cell adhesion molecules on DCs inhibited an equivalent proportion of conjugates from forming between B27 or control DCs and T cells, whereas blocking CD86 on DCs and blocking CD28, CD2, or CD4 on T cells inhibited a greater number of conjugates from forming with control DCs, indicating specific involvement of costimulatory molecules in the reduced formation of conjugates with B27 DCs. Mature B27 molecules on the DC surface were responsible for this decreased formation of conjugates.

Conclusion

In the HLA–B27–transgenic rat model of spondylarthropathy, mature B27 molecules expressed by DCs impair the formation of an antigen‐independent immunologic synapse with naive CD4+ T cells by interfering with the engagement of costimulatory molecules. This phenomenon could potentially affect the production and/or maintenance of regulatory T cells and contribute to the expansion of pathogenic CD4+ T cells.
Presentation of arthritogenic peptide to antigen‐specific T cells by fibroblast‐like synoviocytes
Authors: Tran Chinh N. , Davis Michael J. , Tesmer Laura A. , Endres Judith L. , Motyl Christopher D. , Smuda Craig , Somers Emily C. , Chung Kevin C. , Urquhart Andrew G. , Lundy Steven K. , Kovats Susan , Fox David A.
Published: April 2007

Objective

To assess the ability of rheumatoid arthritis (RA) fibroblast‐like synoviocytes (FLS) to function as antigen‐presenting cells (APCs) for arthritogenic autoantigens found within inflamed joint tissues.

Methods

Human class II major histocompatibility complex (MHC)–typed FLS were used as APCs for murine class II MHC–restricted CD4 T cell hybridomas. Interferon‐γ (IFNγ)–treated, antigen‐loaded FLS were cocultured with T cell hybridomas specific for immunodominant portions of human cartilage gp‐39 (HC gp‐39) or human type II collagen (CII). T cell hybridoma activation was measured by enzyme‐linked immunosorbent assay of culture supernatants for interleukin‐2. Both synthetic peptide and synovial fluid (SF) were used as sources of antigen. APC function in cocultures was inhibited by using blocking antibodies to human class II MHC, CD54, or CD58, or to murine CD4, CD11a, or CD2.

Results

Human FLS could present peptides from the autoantigens HC gp‐39 and human CII to antigen‐specific MHC‐restricted T cell hybridomas. This response required pretreatment of FLS with IFNγ, showed MHC restriction, and was dependent on human class II MHC and murine CD4 for effective antigen presentation. Furthermore, FLS were able to extract and present antigens found within human SF to both the HC gp‐39 and human CII T cell hybridomas in an IFNγ‐dependent and MHC‐restricted manner.

Conclusion

RA FLS can function as APCs and are able to present peptides derived from autoantigens found within joint tissues to activated T cells in vitro. In the context of inflamed synovial tissues, FLS may be an important and hitherto overlooked subset of APCs that could contribute to autoreactive immune responses.
Identification of distinct gene expression profiles in the synovium of patients with systemic lupus erythematosus
Authors: Toukap A. Nzeusseu , Galant C. , Theate I. , Maudoux A. L. , Lories R. J. U. , Houssiau F. A. , Lauwerys B. R.
Published: April 2007

Objective

Synovitis is a common feature of rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE), but the pattern of joint involvement differs in each disease. This study was undertaken to investigate the global gene expression profiles in synovial biopsy tissue from the swollen knees of untreated SLE patients (n = 6), RA patients (n = 7), and osteoarthritis (OA) patients (n = 6).

Methods

Synovial biopsy samples were obtained from the affected knees of patients in the 3 groups by needle arthroscopy. Half of the material was used for extraction of total RNA, amplification of complementary RNA, and high‐density oligonucleotide spotted hybridization arrays. On the remaining tissue samples, real‐time reverse transcription–polymerase chain reaction (RT‐PCR) and immunohistochemical experiments were performed to confirm the microarray data.

Results

SLE synovial biopsy tissue displayed a significant down‐regulation of genes involved in extracellular matrix (ECM) homeostasis and a significant up‐regulation of interferon‐inducible (IFI) genes. Real‐time RT‐PCR experiments confirmed the up‐regulation of selected IFI genes (IFI27, IFI44, and IFI44L) in the SLE synovial tissue. Immunohistochemical analyses showed that 3 molecules involved in ECM regulation, chondroitin sulfate proteoglycan 2, latent transforming growth factor β binding protein 2, and fibroblast activation protein α, were significantly down‐regulated in SLE synovium. In contrast, immunostaining for IFI27, Toll‐like receptor 4, and STAT‐1 resulted in higher quantitative scores in SLE synovial tissue, which could be attributed to the fact that the RA samples had a large population of inflammatory cell infiltrates that were negative for these markers.

Conclusion

Arthritis in SLE has a very distinct molecular signature as compared with that in OA and RA, characterized by up‐regulation of IFI genes and down‐regulation of genes involved in ECM homeostasis.
Activation signal transduction by β1 integrin in T cells from patients with systemic lupus erythematosus
Authors: Nakayamada Shingo , Saito Kazuyoshi , Nakano Kazuhisa , Tanaka Yoshiya
Published: April 2007

Objective

Beta 1 integrin is a representative adhesion molecule for cell–cell and cell–extracellular matrix interactions, and it provides costimulatory signals to T cells. However, the relevance of β1 integrin to T cell activation in systemic lupus erythematosus (SLE) remains unclear. We undertook this study to perform a quantitative and functional analysis of β1 integrin–mediated signaling to T cells in patients with SLE.

Methods

Expression of cell surface molecules was assessed by flow cytometric analysis. Engagement of β1 integrins was performed by crosslinking using a specific monoclonal antibody. To assess tyrosine kinases in β1 integrin–mediated signaling, the cells were transfected with a wild‐type (WT) focal adhesion kinase (FAK), a dominant‐negative truncation of the FAK, or a WT PTEN expression plasmid via nucleofection.

Results

Beta 1 integrin expression was significantly up‐regulated on peripheral blood T cells from patients with active SLE, particularly those with the complication of World Health Organization class IV nephritis, whereas CD28 was significantly decreased in patients with active SLE compared with normal individuals. Beta 1 integrin expression closely correlated with serum hypocomplementemia. Engagement of β1 integrin on T cells from patients with active SLE, but not on those from normal individuals, induced cell proliferation as well as CD40L expression on T cells. Up‐regulation of CD40L expression and T cell proliferation, induced by β1 integrin stimulation, were completely inhibited by transfection of the dominant‐negative truncations of FAK or WT PTEN.

Conclusion

These results suggest that engagement of β1 integrins on SLE T cells could induce FAK‐mediated signaling and subsequent CD40L expression and proliferation. Thus, the β1 integrin signaling cascade might serve to enhance autoreactive T cell activation.
Epistatic effect of plasminogen activator inhibitor 1 and β‐Fibrinogen genes on risk of glomerular microthrombosis in lupus nephritis: Interaction with environmental/clinical factors
Authors: Gong Rujun , Liu Zhihong , Li Leishi
Published: April 2007

Objective

Glomerular microthrombosis (GMT) is not uncommon in lupus nephritis and has been associated with active renal injury and progressive kidney destruction. We undertook this study to determine whether genetic variations of hemostasis factors, such as plasminogen activator inhibitor 1 (PAI‐1) and fibrinogen, affect the risk of GMT.

Methods

A cross‐sectional cohort of 101 lupus nephritis patients with or without GMT was genotyped for PAI‐1 –675 4G/5G and β‐fibrinogen (FGB) –455 G/A gene polymorphisms and analyzed.

Results

PAI‐1 4G/4G homozygotes and FGB A allele carriers were both at increased risk for GMT. When the data were stratified for both gene polymorphisms, an epistatic effect was detected. The PAI‐1 4G/4G genotype was found to predispose to GMT not equally in all lupus nephritis patients, but only in FGB A allele carriers. Likewise, the association between the FGB A allele and GMT was restricted to lupus nephritis patients homozygous for the PAI‐1 4G allele. This epistatic effect was revalidated by the multifactor dimensionality reduction (MDR) analysis and further assessed by incorporating a variety of environmental and clinical factors into the MDR analysis. The most parsimonious model that had a cross‐validation consistency of 100% included joint effects of PAI‐1 and FGB gene polymorphisms and anticardiolipin antibody (aCL) status and yielded the best prediction of GMT, with 66.6% accuracy.

Conclusion

Our findings suggest that risk of GMT in lupus nephritis is attributable, at least in part, to an epistatic effect of PAI‐1 and FGB genes, likely via an interaction with environmental/clinical factors, such as aCL.
Induction of increased cAMP levels in articular chondrocytes blocks matrix metalloproteinase–mediated cartilage degradation, but not aggrecanase‐mediated cartilage degradation
Authors: Karsdal Morten Asser , Sumer Eren Ufuk , Wulf Helle , Madsen Suzi H. , Christiansen Claus , Fosang Amanda J. , Sondergaard Bodil‐Cecilie
Published: April 2007

Objective

Calcitonin has been suggested to have chondroprotective effects. One signaling pathway of calcitonin is via the second messenger cAMP. We undertook this study to investigate whether increased cAMP levels in chondrocytes would be chondroprotective.

Methods

Cartilage degradation was induced in bovine articular cartilage explants by 10 ng/ml oncostatin M (OSM) and 20 ng/ml tumor necrosis factor (TNF). In these cultures, cAMP levels were augmented by treatment with either forskolin (4, 16, or 64 μM) or 3‐isobutyl‐1‐methyl xanthine (IBMX; 4, 16, or 64 μM). Cartilage degradation was assessed by 1) quantification of C‐terminal crosslinking telopeptide of type II collagen fragments (CTX‐II), 2) matrix metalloproteinase (MMP)–mediated aggrecan degradation by 342FFGV‐ G2 assay, 3) aggrecanase‐mediated degradation by 374ARGS‐G2 assay, 4) release of sulfated glycosaminoglycans (sGAG) into culture medium, 5) immunohistochemistry with a monoclonal antibody recognizing the CTX‐II epitope, and 6) toluidine blue staining of proteoglycans. MMP expression and activity were assessed by gelatin zymography.

Results

OSM and TNF induced an 8,000% increase in CTX‐II compared with control (P < 0.001). Both forskolin and IBMX dose‐dependently inhibited release of CTX‐II (P < 0.001). OSM and TNF induced a 6‐fold increase in 342FFGV‐G2, which was abrogated by forskolin and IBMX (by >80%). OSM and TNF stimulated MMP expression as visualized by zymography, and MMP expression was dose‐dependently inhibited by forskolin and IBMX. The highest concentration of IBMX lowered cytokine‐induced release of sGAG by 72%.

Conclusion

Levels of cAMP in chondrocytes play a key role in controlling catabolic activity. Increased cAMP levels in chondrocytes inhibited MMP expression and activity and consequently strongly inhibited cartilage degradation. Specific cAMP modulators in chondrocytes may be potential treatments for cartilage degenerative diseases.
Cover Picture: Carbonyldinitrosyltris(fluorosulfato)tungstate(II) and ‐Molybdate(II) Anions: Synthesis, Spectroscopy, and Density Functional Theory Calculations (Chem. Asian J. 5/2007)
Authors: Xu Qiang , Tsumori Nobuko , Jiang Ling , Kondo Masanobu , Arakawa Ryuichi
Published: April 2007

Tungsten and molybdenum form the carbonyl/nitrosyl complexes [fac‐M(CO)(NO)2(SO3F)3]− (M=W, Mo) in fluorosulfonic acid, which is an example of the strong acids and superacids widely employed as reaction media for the generation, stabilization, and synthetic application of highly electrophilic and often very reactive organic, inorganic, and selected metal–organic cations. These anionic W and Mo complexes are weakly nucleophilic and poorly coordinating. For more information, see the Full Paper by Q. Xu et al. on page 599 ff.
Linking animal models to human congenital diaphragmatic hernia
Authors: Beurskens Niels , Klaassens Merel , Rottier Robbert , de Klein Annelies , Tibboel Dick
Published: April 2007

BACKGROUND:Congenital diaphragmatic hernia (CDH) is a major life‐threatening malformation, occurring in approximately 1 in 3,000 live births. Over the years, different animal models have been used to gain insight into the etiology of this complex congenital anomaly and to develop treatment strategies. However, to date the pathogenic mechanism is still not understood, and treatment remains difficult because of the associated pulmonary hypoplasia and pulmonary hypertension. METHODS: In this review, data available from several animal models will be discussed. The retinoic acid signaling pathway (RA pathway, retinoid pathway) will be addressed as a developmental pathway that is potentially disrupted in the pathogenesis of CDH. Furthermore, genetic factors involved in diaphragm and lung development will be discussed. CONCLUSIONS: With this review article, we aim to provide a concise overview of the current most important experimental genetic data available in the field of CDH. Birth Defects Research (Part A), 2007. © 2007 Wiley‐Liss, Inc.
Zur Tragfähigkeit unbewehrter Betonwände
Authors: Hegger Josef , Dreßen Tobias , Will Norbert
Published: April 2007

Dem Nachweis von Druckgliedern aus unbewehrtem Beton nach DIN 1045‐1 liegen vereinfachte Ansätze zugrunde, die bei einer Bemessung bei großer Ausmitte und Schlankheit zu unwirtschaftlichen Querschnittsdicken führen. Im vorliegenden Beitrag wird auf Grundlage der Prinzipien nach DIN 1045‐1 ein Bemessungskonzept für Druckglieder hergeleitet, das eine wirtschaftliche, einfache und normenkonforme Bemessung unbewehrter Querschnitte ermöglicht. Die Berücksichtigung der Betonzugfestigkeit erschließt dabei weitere Traglastreserven.
Kathodischer Korrosionsschutz von Stahl in Beton: Instandsetzung des Parkhauses “Am Gericht” in Frankfurt am Main
Authors: Klein Hans‐H. , Schade Andreas , Eichler Thorsten , Isecke Bernd , Pruckner Franz , Michel Stefan
Published: April 2007

Die Instandsetzung von Stahlbetonbauteilen bzw.‐werken, welche durch chloridinduzierte Korrosion der Bewehrung gefährdet oder bereits geschädigt sind, hat in den letzten Jahrzehnten weltweit an Bedeutung gewonnen. Der kathodische Korrosionsschutz, als elektrochemisches Instandsetzungsverfahren, bildet in diesem Fall eine zuverlässige und oftmals kostengünstige Methode zur Instandsetzung. Am Beispiel des Parkhauses “Am Gericht” in Frankfurt am Main werden die Durchführung solch einer Maßnahme sowie die Besonderheiten des Verfahrens beschrieben. Es werden die theoretischen Hintergründe erläutert und die praktische Umsetzung sowie zu klärende Detailfragen beschrieben. Die Daten der ersten Depolarisationsmessungen zeigen den aktuellen Zustand der Anlage sowie des Schutzobjektes.
Activity of human P450 2D6 in biphasic solvent systems
Authors: Zhao Jin , Tan Elaine , Ferras Julian , Auclair Karine
Published: April 2007

Several limitations have restricted the use of P450 enzymes in synthesis, including the narrow substrate specificity of some P450 isoforms, the need for a redox partner and an expensive cofactor, incompatibility with organic solvents, and poor stability. We previously demonstrated that the natural redox partner and cofactor of the promiscuous P450s 3A4 and 2D6 can be efficiently substituted with some cheap hydrogen peroxide donors or organic peroxides. We report here that P450 2D6 maintains as much as 76% of its activity when used in buffer/organic emulsions. Product formation in biphasic solvent systems is comparable whether the natural redox partner and cofactor are used, or a surrogate. As reported for other enzymes, a correlation is observed between the logPand the suitability of a solvent for enzymatic activity. Moreover, the utility of our system was established by demonstrating the transformation of a novel hydrophobic substrate, not modified by P450 2D6 in the absence of organic solvent. Biotechnol. Bioeng. 2007;98; 508–513. © 2007 Wiley Periodicals, Inc.
InXy and SeXy, compact heterologous reporter proteins for mammalian cells
Authors: Fluri David A. , Kelm Jens M. , Lesage Guillaume , Baba Marie Daoud‐El , Fussenegger Martin
Published: April 2007

Mammalian reporter proteins are essential for gene‐function analysis, drugscreening initiatives and as model product proteins for biopharmaceutical manufacturing. Bacillus subtilis can maintain its metabolism by secreting Xylanase A (XynA), which converts xylan into shorter xylose oligosaccharides. XynA is a family 11 xylanase monospecific for D‐xylose containing substrates. Mammalian cells transgenic for constitutive expression of wild‐type xynA showed substantial secretion of this prokaryotic enzyme. Deletion analysis confirmed that a prokaryotic signal sequence encoded within the first 81 nucleotides was compatible with the secretory pathway of mammalian cells. Codon optimization combined with elimination of the prokaryotic signal sequence resulted in an exclusively intracellular mammalian Xylanase A variant (InXy) while replacement by an immunoglobulin‐derived secretion signal created an optimal secreted Xylanase A derivative (SeXy). A variety of chromogenic and fluorescence‐based assays adapted for use with mammalian cells detected InXy and SeXy with high sensitivity and showed that both reporter proteins resisted repeated freeze/thaw cycles, remained active over wide temperature and pH ranges, were extremely stable in human serum stored at room temperature and could independently be quantified in samples also containing other prominent reporter proteins such as the human placental alkaline phosphatase (SEAP) and the Bacillus stearothermophilus‐derived secreted α‐amylase (SAMY). Glycoprofiling revealed that SeXy produced in mammalian cells was N‐ glycosylated at four different sites, mutation of which resulted in impaired secretion. SeXy was successfully expressed in a variety of mammalian cell lines and primary cells following transient transfection and transduction with adeno‐associated virus particles (AAV) engineered for constitutive SeXy expression. Intramuscular injection of transgenic AAVs into mice showed significant SeXy levels in the bloodstream. InXy and SeXy are highly sensitive, compact and robust reporter proteins, fully compatible with pre‐existing marker genes and can be assayed in high‐throughput formats using very small sample volumes. Biotechnol. Bioeng. 2007;98:655–667. © 2007 Wiley Periodicals, Inc.
Opioid medications and longitudinal risk of delirium in hospitalized cancer patients
Authors: Gaudreau Jean‐David , Gagnon Pierre , Roy Marc‐André , Harel François , Tremblay Annie
Published: April 2007

BACKGROUND.

Delirium is an important problem in hospitalized cancer patients. The objective of this study was to determine whether exposure to corticosteroids, benzodiazepines, or opioids predicted delirium.

METHODS.

A prospective cohort study was conducted in an oncology/internal medicine population. Patients were assessed continuously for the presence of delirium until they were discharged by using the Nursing Delirium Screening Scale (Nu‐DESC). Follow‐up for outcome began after incident delirium. The primary outcome was the presence of a delirium event, which was defined as a Nu‐DESC score >1. Strengths of associations of medications with delirium were expressed as odds ratios (ORs) in univariate and multivariate analyses.

RESULTS.

In total, 114 patients (1823 patient‐days) met the inclusion criteria for the study. The mean follow‐up from incident delirium was 16 days. The mean number of delirium events by patient was 6 (total number, 667 delirium events). Analysis by day on several occasions revealed significant associations between opioids and delirium. Corticosteroids and benzodiazepines were not associated significantly with an increased risk of delirium on any given day. Analysis by patient using generalized estimating equation (GEE) models showed an increased risk of delirium on any day of follow‐up associated with opioid exposure in univariate analysis (OR of 1.70; P < .0001). The association remained significant after adjustment for corticosteroid, benzodiazepine, and antipsychotic exposure using GEE regressions (OR of 1.37; P = .0033). Truncating follow‐up at 30 days did not affect the results (OR of 1.38; P < .032).

CONCLUSIONS.

Exposure to opioids during hospitalization was associated significantly with an increased longitudinal risk of delirium. Cancer 2007. © 2007 American Cancer Society.
Small bowel carcinoid (enterochromaffin cell) neoplasia exhibits transforming growth factor–β1‐mediated regulatory abnormalities including up‐regulation of C‐Myc and MTA1
Authors: Kidd Mark , Modlin Irvin M. , Pfragner Roswitha , Eick Geeta N. , Champaneria Manish C. , Chan Anthony K. , Camp Robert L. , Mane Shrikant M.
Published: April 2007

BACKGROUND.

Although it is known that small intestinal carcinoids are derived from enterochromaffin (EC) cells, these cells remain poorly characterized and little is known of the growth regulatory mechanisms of these neuroendocrine cells. Down‐regulation or loss of the transforming growth factor‐β1 (TGFβ1) cytostatic program and activation of TGFβ‐mediated transcriptional networks is associated with uncontrolled growth and metastasis in other neural tumors, glioblastomas. Whether this phenomenon is common to small intestinal carcinoid tumors was investigated.

METHODS.

The effects of TGFβ1 on cultured normal EC cells (isolated by FACS sorting) and the neoplastic EC cell line, KRJ‐I, was assessed using the MTT assay. The TGFβRII transcript and protein were identified in tumor cells and the effects of TGFβ1 on SMAD2 phosphorylation and nuclear translocation quantified. The time‐dependent response of SMAD4, SMAD7, c‐Myc, and P21WAF1/CIP1 protein expression and c‐Myc and p21WAF1/CIP1 transcript was measured in response to TGFβ1 and the transcript expression of candidate downstream targets, MTA1 and E‐cadherin, were assessed.

RESULTS.

TGFβ1 inhibited normal EC cell proliferation (IC50 = 17 pM) but stimulated neoplastic EC cell proliferation (EC50 = 22 pM). In tumor cells, significantly decreased transcript (P < .01) of TGFβRII was identified, but no receptor mutations were identified and protein expression was evident. TGFβ1 (1 ng/mL) resulted in SMAD2 phosphorylation and <7% nuclear expression compared with 93% in normal EC cells. In neoplastic cells, TGFβ1 (1 ng/mL) caused a decrease in SMAD4 (>16%, P < .05), whereas SMAD7 and c‐Myc transcript and protein were respectively increased >21% (P < .05) and ≈40% (P < .002). TGFβ1 (1 ng/mL) also decreased p21WAF1/CIP1 transcript by 60% (P < .001) and protein that was undetectable at 24 hours. Expression of the downstream targets of the c‐Myc pathway, MTA1, was increased (20%) and E‐cadherin decreased (30%).

CONCLUSIONS.

The neoplastic EC cell is characterized by loss of TGFβ‐1‐mediated growth inhibition and, similar to glioblastomas, utilizes the TGFβ system to induce gene responses associated with growth promotion (c‐Myc and the ERK pathway), invasion (E‐cadherin), and metastasis (MTA1). Cancer 2007. © 2007 American Cancer Society.
Cover Picture: Acetylene‐Substituted Phosphane Oxides: Building Blocks for Macrocycles (Eur. J. Org. Chem. 15/2007)
Authors: van Assema Sander G. A. , de Jong G. Bas , Ehlers Andreas W. , de Kanter Frans J. J. , Schakel Marius , Spek Anthony L. , Lutz Martin , Lammertsma Koop
Published: April 2007

The cover picture shows the synthesis of three novel phosphorus‐based macrocycles with acetylenic scaffolds from simple and accessible building blocks. The 14‐membered macrocycle was obtained as cis and trans isomers from cyclization of diisopropylphosphoramidic dibromide and 1,2‐bis(ethynyl)benzene. The four‐ and six‐edged macrocycles in which the iPr2NP(O) units are connected through 1,3‐butadiyne rods were obtained after multiple acetylene coupling reactions under oxidative Hay conditions starting from the diethynylphosphinic amide building block. Further details are discussed in the article by K. Lammertsma et al. on p 2405 ff.
Identifying bacterial species using CE–MS and SEQUEST with an empirical scoring function
Authors: Hu Anren , Lo Alan A.‐L. , Chen Cheng‐Tung , Lin Kuo‐Chih , Ho Yen‐Peng
Published: April 2007

CE‐MS/MS analysis of proteolytic digests of bacterial cell extracts was combined with SEQUEST searching and a new scoring system to identify bacteria species in bacterial mixtures. Searches of MS/MS spectra against protein databases enabled the identification of bacterial species by the matching of the proteins associated with the corresponding species. An empirical scoring function was obtained by evaluating the SEQUEST search results of 38 samples that contained single bacterial species. The scoring by the empirical function helped move up the positive identification results from their original positions in the ranking based on Xcorr values alone. Therefore, the identification of bacteria in the samples that contained bacterial mixtures was improved. Bacterial species in 20 bacterial mixtures, including one real sample, were correctly identified by database searches and the new scoring function.
Clustering based on geometry and interactions of turbulence bursting rate processes in a trough region
Authors: Mazumder Rahul
Published: April 2007

This paper aims at understanding turbulence occurring due to fluid flow in the trough region between two artificial adjacent asymmetric waveforms in an open‐channel using velocity data collected by 3‐D Acoustic Doppler Velocimeter (ADV), concentrating on interactions among the turbulence bursting phenomena across different spatial locations. The Statistical Learning stage of the analysis begins with the identification and extraction of statistically informative and physically interpretable features in the geometry of the Bursting Rate Processes (BRP). Statistical measures characterising the differences among the concerned processes have been developed and used for splitting the trough region into different regions based on the geometry, structure and randomness in the BRP, using the principles of statistical clustering involving parametric, non‐parametric techniques and ideas of information theoretic entropy. Experimental observations support the existence of certain BRP which may be considered to be dominant over the others in an almost global sense. The issue of identifying a single bursting phenomenon that changes its orientation strongly relative to others or its closest neighbour across all spatial locations or stretches of vertical heights for every horizontal location and its importance in the entire physical scenario in the light of the spatial clustering problem has been addressed and settled too. Copyright © 2007 John Wiley & Sons, Ltd.
The principle of channel overloading and design of some practical schemes
Authors: Nadal Florence , Sari Hikmet
Published: April 2007

Channel overloading, which refers to accommodating a larger number of users on a channel than can be achieved with orthogonal signalling, is currently a very hot topic for future wireless systems. A number of approaches have been described in the literature and the most efficient of them are based on using multiple sets of orthogonal signal waveforms. Multiuser interference, which is inherent to channel overloading, is handled using maximum likelihood (ML) detection or iterative interference cancellation. In this paper, we discuss the principle of channel overloading and give the overload limits with different signal constellations. We interpret the various channel overloading schemes available in the literature as multilevel coding of an expanded signal constellation, and this interpretation gives us insight into their performance and limitations and enables us to construct some novel multiple access schemes. Copyright © 2007 John Wiley & Sons, Ltd.
Maximum precision‐lifetime curve for joint sensor selection and data routing in sensor networks
Authors: Bulbul Kerem , Ercetin Ozgur
Published: April 2007

In many classes of monitoring applications employing battery‐limited sensor networks, periodic sampling of an area with a given precision level is required. For such applications, we provide mathematical programming formulations for deriving the optimal trade‐off curve between network lifetime and data precision, and design a practical heuristic for near‐optimal operation. The properties of our models and the effectiveness of our heuristic are demonstrated by computational experiments. Copyright © 2007 John Wiley & Sons, Ltd.
Performance analysis of nonlinearly amplified M‐QAM signals in MIMO channels
Authors: Sulyman Ahmed Iyanda , Ibnkahla Mohamed
Published: April 2007

In this paper, we investigate the effect of nonlinearity in multiple input multiple output (MIMO) channels. New results on the error rate performance of several M‐QAM constellations in linear and nonlinear MIMO channels are presented. The results show that for any MIMO configuration, performance degradation due to nonlinearity reduces as the fading gets more severe, and for a particular fading channel, the degradation increases as the MIMO dimension is increased. Optimum operating points for nonlinear amplifiers in MIMO channels are then reported. At these points, highly efficient utilisation of the amplifiers are achieved at minimal performance loss. Copyright © 2007 John Wiley & Sons, Ltd.
Isolation and endotoxin activities of lipopolysaccharides from cyanobacterial cultures and complex water blooms and comparison with the effects of heterotrophic bacteria and green alga
Authors: Bernardová Kateřina , Babica Pavel , Maršálek Blahoslav , Bláha Luděk
Published: April 2007

Massive cyanobacterial water blooms are serious environmental and health problems worldwide. While some cyanobacterial toxins such as peptide microcystins have been investigated extensively, other toxic components of cyanobacteria (e.g. lipopolysaccharides, LPS) are poorly understood. The present study characterized endotoxin activities of LPS isolated from (i) laboratory cyanobacterial cultures, (ii) cyanobacterial water bloom samples dominated by Microcystis sp., Planktothrix sp., Aphanizomenon sp. and Anabaena sp., (iii) heterotrophic Gram‐negative bacteria Escherichia coli, Kluyvera intermedia, Pseudomonas putida and Pseudomonas fluorescens and (iv) green alga Pseudokirchneriella subcapitata. Toxicity results derived with Limulus amebocyte lysate assay (LAL‐test) showed that endotoxin activities of LPS from both cyanobacteria and heterotrophic bacteria were comparable and the values were within a similar range (1 × 103–1 × 106 Endotoxin Units, EU, per mg of isolated LPS). The highest activities among the cyanobacterial samples were observed in the Aphanizomenon sp. dominated water bloom. The results also suggest generally higher endotoxin activities in complex natural samples than in laboratory cyanobacterial cultures. Further, experiments with the eukaryotic green alga P. subcapitata demonstrated a need for careful purification of the LPS extracts prior to testing with the LAL assay as several contaminants may overestimate endotoxin activities. This study shows relatively high pyrogenicity of LPS from various cyanobacteria. Further research should focus on detailed toxicological and ecotoxicological characterization of LPS in massive cyanobacterial water blooms. Copyright © 2007 John Wiley & Sons, Ltd.
Mixed covering arrays on graphs
Authors: Meagher Karen , Moura Lucia , Zekaoui Latifa
Published: April 2007

Covering arrays have applications in software, network and circuit testing. In this article, we consider a generalization of covering arrays that allows mixed alphabet sizes as well as a graph structure that specifies the pairwise interactions that need to be tested. Letkandnbe positive integers, and letGbe a graph withkverticesv1,v2,…,vkwith respective vertex weightsg1≤g2≤ … ≤gk. Amixed covering arrayonG, denoted by$CA( {n,G,\;\prod\nolimits_{i = 1}^k {g_i } } )$, is ann×karray such that columnicorresponds tovi, cells in columniare filled with elements from ℤgiand every pair of columnsi,jcorresponding to an edgevi,vjinGhas every possible pair from ℤgi× ℤgjappearing in some row. The number of rows in such array is called itssize. Given a weighted graphG, a mixed covering array onGwith minimum size is calledoptimal. In this article, we give upper and lower bounds on the size of mixed covering arrays on graphs based on graph homomorphisms. We provide constructions for covering arrays on graphs based on basic graph operations. In particular, we construct optimal mixed covering arrays on trees, cycles and bipartite graphs; the constructed optimal objects have the additional property of being nearly point balanced. © 2007 Wiley Periodicals, Inc. J Combin Designs 15: 393–404, 2007
Activated microglia affect the nigro‐striatal dopamine neurons differently in neonatal and aged mice treated with 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine
Authors: Sawada Hirohide , Hishida Ryohei , Hirata Yoko , Ono Kenji , Suzuki Hiromi , Muramatsu Shin‐ichi , Nakano Imaharu , Nagatsu Toshiharu , Sawada Makoto
Published: April 2007

Microglia play an important role in the inflammatory process that occurs in Parkinson's disease (PD). Activated microglia produce cytokines and neurotrophins and may have neurotoxic or neurotrophic effects. Because microglia are most proliferative and easily activated during the neonatal period, we examined the effects of neonatal microglia activated with lipopolysaccharide (LPS) on the nigro‐striatal dopamine neurons in mice treated with 1‐methyl‐4‐phenyl‐1,2,3,6‐tetrahydropyridine (MPTP), in comparison with activated microglia from the aged mice. By MPTP administration to neonatal mice, the number of dopamine neurons in the substantia nigra (SN) was decreased significantly, whereas that in the mice treated with LPS and MPTP was recovered to normal, along with significant microglial activation. Tyrosine hydroxylase (TH) activity, the levels of dopamine and 3,4‐dihydroxyphenylacetic acid (DOPAC), and the levels of pro‐inflammatory cytokines IL‐1β and IL‐6 in the midbrain were elevated in the neonates treated with LPS and MPTP. On the contrary, although the number of dopamine neurons in the 60‐week‐old mice treated with MPTP was also decreased significantly, the microglial activation by LPS treatment caused a further decrease in their number. These results suggest that the activated microglia in neonatal mice are different from those in aged mice, with the former having neurotrophic potential toward the dopamine neurons in the SN, in contrast to the neurotoxic effect of the latter. © 2007 Wiley‐Liss, Inc.
Peptidyl argininedeiminase 2 CpG island in multiple sclerosis white matter is hypomethylated
Authors: Mastronardi Fabrizio G. , Noor Abdul , Wood D. Denise , Paton Tara , Moscarello Mario A.
Published: April 2007

In previous studies, we documented increased citrullinated myelin basic protein (MBP) was present in MBP isolated from multiple sclerosis (MS) normal appearing white matter (NAWM). This increase was due to the myelin enzyme peptidyl argininedeiminase 2 (PAD2). In this study, we show that methylation of cytosine of the PAD2 promoter in DNA from MS NAWM was decreased to one‐third of the level of that in DNA from normal white matter. The PAD2 promoter in DNA from thymus obtained from the same MS patients and white matter DNA from Alzheimer's, Huntington's, and Parkinson's was not hypomethylated. DNA demethylase activity in supernatants prepared from NAWM of MS patients was 2‐fold higher than the DNA demethylase from normal, Alzheimer's, Huntington's and Parkinson's disease white matter. The amount of PAD2 enzyme and citrullinated MBP was increased in MS NAWM. The decreased methylation of cytosines in the PAD2 promoter may explain the increased synthesis of PAD2 protein that is responsible for the increased amount of citrullinated MBP, which in turn results in loss of myelin stability in MS brain. © 2007 Wiley‐Liss, Inc.
Comments and recommendations regarding the hypothesis testing controversy
Authors: Bonett Douglas G. , Wright Thomas A.
Published: April 2007

Hypothesis tests are routinely misinterpreted in scientific research. Specifically, the failure to reject a null hypothesis is often interpreted as support for the null hypothesis while the rejection of a null hypothesis is often interpreted as evidence of an important finding. Many of the most frequently used hypothesis tests are “non‐informative” because the null hypothesis is known to be false prior to hypothesis testing. We discuss the limitations of non‐informative hypothesis tests and explain why confidence intervals should be used in their place. Several examples illustrate the use and interpretation of confidence intervals. Copyright © 2007 John Wiley & Sons, Ltd.
Racial differences in promotion candidate performance and reactions to selection procedures: a field study in a diverse top‐management context
Authors: Becton John Bret , Feild Hubert S. , Giles William F. , Jones‐Farmer Allison
Published: April 2007

The present study examined African‐American and White promotion candidates' reactions to and performance on selection procedures that were completed within a police department where African Americans occupied the majority of top‐management positions. Reactions (perceived job relatedness and test‐taking motivation) of 187 candidates competing for promotion to the rank of sergeant were assessed after completing a written job knowledge test and a situational interview. Analyses showed that both the African‐American and White candidates judged the situational interview to be more job‐related than the pencil‐and‐paper job knowledge test. In addition, African Americans perceived both selection measures to be more job‐related and reported higher levels of test‐taking motivation than White candidates even though African Americans performed more poorly than White candidates on the paper‐and‐pencil test. These results challenge the contention that lower test‐taking motivation for African‐American candidates is related to racial differences in performance on pencil‐ and‐paper tests. Implications and directions for future research on reactions to selection procedures for promotion in racially diverse employment settings are discussed. Copyright © 2007 John Wiley & Sons, Ltd.