bluuebunny/crossref_metadata_2025 huggingface dataset:
How to successfully apply animal studies in experimental allergic encephalomyelitis to research on multiple sclerosis
Authors: Steinman Lawrence , Zamvil Scott S.
Published: June 2006

In their Point of View entitled “Experimental Allergic Encephalomyelitis: A Misleading Model of Multiple Sclerosis,” Sriram and Steiner1 wrote, “The most disappointing aspect of EAE [experimental allergic encephalomyelitis] as a potential model for MS is its almost total inability to point toward a meaningful therapy or therapeutic approach for MS.” Actually, EAE has led directly to the development of three therapies approved for use in multiple sclerosis (MS): glatiramer acetate, mitoxantrone, and natalizumab. Several new approaches to MS are in clinical trials based on positive indications in preclinical work relying on EAE. New clues to the pathogenesis of MS and new potential surrogate markers for MS are shown from research involving EAE when it is critically coupled with actual findings in MS. There are pitfalls in overreliance on the EAE model, or on any animal model for any human disease. Nevertheless, over the past 73 years, the EAE model has proved itself remarkably useful for aiding research on MS. Ann Neurol 2006;60:12–21
Thermodynamic and spectroscopic study of the binding of dimethyltin(IV) by citrate at 25 °C
Authors: Cardiano Paola , Giuffrè Ottavia , Pellerito Lorenzo , Pettignano Alberto , Sammartano Silvio , Scopelliti Michelangelo
Published: June 2006

Thermodynamic (potentiometric and calorimetric) and spectroscopic (1H NMR, 119Sn Mössbauer) studies were performed in aqueous solution in order to characterize the interaction of dimethyltin(IV) cation with citrate ligand. Six species {(CH3)2Sn(cit)−; [(CH3)2Sn]2(cit)22−; (CH3)2Sn(cit)H0; (CH3)2Sn(cit)OH2−; [(CH3)2Sn]2(cit)OH0; [(CH3)2Sn]2(cit)(OH)2−} were found. All the species formed in this system are quite stable and formation percentages are fairly high. For example, at pH = 7.5 and C = Ccit = 10 mmol l−1, Σ% for [(CH3)2Sn]2(cit)(OH)2− and (CH3)2Sn(cit)OH2− species reaches 65%. Overall thermodynamic parameters obtained show that the main contribution to stability is entropic in nature. Thermodynamic parameters were discussed in comparison with a simple tricarboxylate ligand (1,2,3‐propanetricarboxylate). Two empirical relationships were derived from thermodynamic formation parameters. Spectroscopic results fully confirm the speciation model defined potentiometrically and show the mononuclear species to have an eq‐(CH3)2Tbp structure with different arrangements around the metal, while for [(CH3)2Sn]2(cit)(OH)2− there are two different Sn(IV) environments, namely trans‐(CH3)2 octahedral and cis‐(CH3)2 Tbp. Copyright © 2005 John Wiley & Sons, Ltd.
Efficacy and safety of adalimumab in patients with ankylosing spondylitis: Results of a multicenter, randomized, double‐blind, placebo‐controlled trial
Authors: van der Heijde Désirée , Kivitz Alan , Schiff Michael H. , Sieper Joachim , Dijkmans Ben A. C. , Braun Jürgen , Dougados Maxime , Reveille John D. , Wong Robert L. , Kupper Hartmut , Davis John C.
Published: June 2006

Objective

To evaluate the safety and efficacy of adalimumab, a fully human recombinant IgG1 monoclonal antibody that specifically targets human tumor necrosis factor, in patients with active ankylosing spondylitis (AS).

Methods

This was a multicenter, randomized (2:1 ratio), double‐blind, placebo‐controlled study to evaluate a subcutaneous injection of adalimumab, 40 mg every other week, compared with placebo for 24 weeks. The primary efficacy end point was the percentage of patients with a 20% response according to the ASsessment in Ankylosing Spondylitis International Working Group criteria for improvement (ASAS20) at week 12. Secondary outcome measures included the ASAS20 at week 24 and multiple measures of disease activity, spinal mobility, and function, as well as ASAS partial remission.

Results

At week 12, 58.2% of adalimumab‐treated patients (121 of 208) achieved an ASAS20 response, compared with 20.6% of placebo‐treated patients (22 of 107) (P < 0.001). More patients in the adalimumab group (45.2% [94 of 208]) than in the placebo group (15.9% [17 of 107]) had at least a 50% improvement in the Bath Ankylosing Spondylitis Disease Activity Index at week 12 (P < 0.001). Significant improvements in the ASAS40 response and the response according to the ASAS5/6 criteria at weeks 12 and 24 were also demonstrated (P < 0.001). Partial remission was achieved by more adalimumab‐treated patients than placebo‐treated patients (22.1% versus 5.6%; P < 0.001). Adalimumab‐treated patients reported more adverse events (75.0% versus 59.8% of placebo‐treated patients; P < 0.05), but there was no statistically significant difference in the incidence of infections. Most adverse events were mild or moderate in severity.

Conclusion

Adalimumab was well‐tolerated during the 24‐week study period and was associated with a significant and sustained reduction in the signs and symptoms of active AS.
Overexpression of synoviolin in peripheral blood and synoviocytes from rheumatoid arthritis patients and continued elevation in nonresponders to infliximab treatment
Authors: Toh Myew‐Ling , Marotte Hubert , Blond Jean‐Luc , Jhumka Umar , Eljaafari Assia , Mougin Bruno , Miossec Pierre
Published: June 2006

Objective

Synoviolin is a novel E3 ubiquitin ligase that has been implicated in the pathogenesis of rheumatoid arthritis (RA). The purpose of this study was to examine the expression and regulation of synoviolin by tumor necrosis factor α (TNFα), both in vivo and in vitro.

Methods

A total of 54 RA patients and 23 healthy control subjects were analyzed before, 4 hours after the first infusion, and at week 22 of infliximab treatment. Clinical response was assessed by the American College of Rheumatology criteria for 20% improvement and the Disease Activity Score in 28 joints (DAS28) at 6 months. Synoviolin messenger RNA expression was measured by real‐time reverse transcription–polymerase chain reaction in peripheral blood (PB) and fibroblast‐like synoviocytes (FLS) and with and without TNFα or interleukin‐1β (IL‐1β) stimulation.

Results

Synoviolin expression was increased in whole PB obtained from RA patients as compared with that from healthy controls and was significantly reduced early and late after infliximab treatment in responders, but in not nonresponders. Reduction in synoviolin expression was associated with reduced levels of markers of disease activity, including C‐reactive protein levels. Nonresponders to infliximab therapy had significantly higher synoviolin expression at baseline as compared with responders, and this elevation persisted despite infliximab therapy. PB CD14+ monocytes expressed increased synoviolin levels compared with CD3+ lymphocytes, and TNFα or IL‐1β induced a further increase in expression in CD3+ cells. TNFα or IL‐1β induced sustained synoviolin expression in RA FLS.

Conclusion

Elevated PB levels of synoviolin were identified in circulating PB mononuclear cells and were associated with nonresponse to infliximab treatment. Sustained up‐regulation of synoviolin by IL‐1β and TNFα may contribute to prolonged survival of immune cells and dysregulated FLS proliferation, leading to RA chronicity.
Direct modulation of rheumatoid inflammatory mediator expression in retinoblastoma protein–dependent and –independent pathways by cyclin‐dependent kinase 4/6
Authors: Nonomura Yoshinori , Nagasaka Kenji , Hagiyama Hiroyuki , Sekine Chiyoko , Nanki Toshihiro , Tamamori‐Adachi Mimi , Miyasaka Nobuyuki , Kohsaka Hitoshi
Published: June 2006

Objective

It is known that the cyclin‐dependent kinase inhibitor (CDKI) gene p21Cip1 suppresses rheumatoid inflammation by down‐modulating type I interleukin‐1 receptor (IL‐1RI) expression and inhibiting JNK activity. The purpose of this study was to determine whether CDK activity directly modulates the production of inflammatory molecules in patients with rheumatoid arthritis (RA).

Methods

Genes for the CDKIs p16INK4a and p18INK4c, a constitutively active form of retinoblastoma (RB) gene product, cyclin D1, and CDK‐4, were transferred into RA synovial fibroblasts (RASFs). RASFs were also treated with a synthetic CDK‐4/6 inhibitor (CDK4I). Levels of matrix metalloproteinase 3 (MMP‐3), monocyte chemoattractant protein 1 (MCP‐1), and IL‐1RI expression were determined by Northern blotting, real‐time polymerase chain reaction analysis, and enzyme‐linked immunosorbent assay. CDKIs were immunoprecipitated to reveal their association with JNK.

Results

Transfer of the p16INK4a and p18INK4c genes and CDK4I suppressed the production of MMP‐3 and MCP‐1. Unlike p21Cip1, neither CDKI gene inhibited IL‐1RI or JNK. The expression of MMP‐3 was up‐regulated when CDK‐4 activity was augmented. This regulation functioned at the messenger RNA (mRNA) level in MMP‐3, but not in MCP‐1. Transfer of active RB suppressed the production of MMP‐3 and MCP‐1 without changing their mRNA levels.

Conclusion

CDK‐4/6 modulated the production of MMP‐3 and MCP‐1. MMP‐3 production was regulated primarily at the mRNA level in an RB‐independent manner, whereas MCP‐1 production was controlled posttranscriptionally by RB. These results show that cell cycle proteins are associated with control of mediators of inflammation through multiple pathways.
Association between serum total cholesterol level and renal outcome in systemic lupus erythematosus
Authors: Tisseverasinghe Annaliese , Lim Sooyeol , Greenwood Celia , Urowitz Murray , Gladman Dafna , Fortin Paul R.
Published: June 2006

Objective

To determine whether an elevated serum total cholesterol level in a first‐available sample obtained at a systemic lupus erythematosus (SLE) clinic is associated with worse renal outcome in patients with SLE.

Methods

Survival analysis methods were used on prospectively gathered data on 1,060 patients with SLE who were registered in the University of Toronto Lupus Databank. The effect of total cholesterol and 15 additional variables on the outcomes of renal deterioration, end‐stage renal disease (ESRD), and death was assessed using Cox proportional hazards methods.

Results

In 474 (45%) of the 1,060 patients, the total cholesterol level exceeded 5.2 mmoles/liter. In the entire study group, the median total cholesterol level was 5.1 mmoles/liter (range 1.6–17.1). During a mean followup period of 8.8 years, 93 patients (9%) experienced renal deterioration, 42 patients (4%) had ESRD, and 161 deaths occurred, 48 (30%) of which were associated with renal dysfunction (renal death), and 113 (70%) of which were not associated with renal dysfunction (nonrenal death). Kaplan‐Meier survival estimates for each outcome were statistically significantly different between patients with normal versus those with elevated total cholesterol levels (cutoff 5.2 mmoles/liter), with a worse outcome observed among those with an elevated total cholesterol concentration. In multivariate analyses, total cholesterol level (hazard ratio [HR] 1.17, 95 confidence interval [95% CI] 1.01–1.36), serum creatinine level (HR 1.06, 95% CI 1.04–1.07), proteinuria (HR 2.44, 95% CI 1.25–4.76), the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index (HR 1.44, 95% CI 1.16–1.80), and corticosteroid dose (HR 1.01, 95% CI 1.00–1.02) were associated with renal deterioration. Significant predictors of ESRD were baseline proteinuria (HR 6.24, 95% CI 1.96–19.88) and serum creatinine level (HR 1.15, 95% CI 1.08–1.22). The total cholesterol level was correlated with death (HR 1.20, 95% CI 1.11–1.29), retaining statistical significance for renal death (HR 1.33, 95% CI 1.20–1.47) but not for nonrenal death (HR 1.12, 95% CI 0.99–1.25).

Conclusion

Those results indicate that an elevated serum total cholesterol level in a first‐available sample obtained at an SLE clinic is associated with adverse renal outcomes and mortality.
The heritable determinants of cartilage oligomeric matrix protein
Authors: Williams Frances M. K. , Andrew Toby , Saxne Tore , Heinegard Dick , Spector Tim D. , MacGregor Alex J.
Published: June 2006

Objective

Cartilage oligomeric matrix protein (COMP) is a cartilage matrix macromolecule. The protein is detectable in serum and has been investigated as a biomarker of osteoarthritis (OA). An association between COMP and OA has been shown, yet the precise factors governing serum levels of COMP remain unclear. The aim of this study was to determine whether genetic factors influence serum levels of COMP.

Methods

A classic twin study was conducted using COMP levels in serum obtained from healthy female twin volunteers. COMP levels were determined by an inhibition enzyme‐linked immunosorbent assay method. The heritability of COMP was determined by comparing correlation among 160 monozygotic and 349 dizygotic twin pairs. Data on potential confounding factors, including age, body mass index, and the presence of OA as assessed by hand, hip, and knee radiographs, were included in the analysis.

Results

Serum levels of COMP showed a correlation of 0.72 (95% confidence interval [95% CI] 0.65–0.80) among monozygotic twin pairs and 0.47 (95% CI 0.39–0.55) in dizygotic pairs. This equated to an estimated heritability for COMP of 40% (95% CI 20–60%). Although age and body mass index were found to be significantly associated with COMP in regression analysis, taking the effects of these factors into account did not influence the estimate of heritability.

Conclusion

This study showed that heritable factors influence serum levels of the cartilage matrix biomarker COMP. Together with other published data, the results suggest that genetic factors operate at an early stage in the etiologic pathways that influence the development of radiographically discernible OA.
Increased case fatality rates following a first acute cardiovascular event in patients with rheumatoid arthritis
Authors: Van Doornum S. , Brand C. , King B. , Sundararajan V.
Published: June 2006

Objective

Among patients with rheumatoid arthritis (RA), cardiovascular mortality is increased compared with the rate among unaffected peers. In this study, 30‐day mortality rates following a first acute cardiovascular event (myocardial infarction or stroke) were compared between RA patients and the general population.

Methods

All cases of a first acute cardiovascular event between July 1, 2001 and November 30, 2003 in Victoria, Australia were identified from hospital discharge data. Individuals were classified as having RA when an International Classification of Diseases, Ninth Revision, Clinical Modification (ICD‐9‐CM) or an International Statistical Classification of Diseases and Related Health Problems, Tenth Revision, Australian Modification code for RA was recorded at the index admission or during the previous 5 years. Thirty‐day mortality rates were determined from linkage to the state death registry.

Results

A total of 29,924 patients experienced a first cardiovascular event during the study period, 359 (1.2%) of whom had RA. Thirty‐day cardiovascular mortality was 17.6% in RA patients versus 10.8% in non‐RA patients. In fully adjusted models, the odds ratio (OR) for cardiovascular death in RA patients following a first acute cardiovascular event was 1.6 (95% confidence interval [95% CI] 1.2–2.2). Analysis of index event subgroups revealed that this increased case fatality rate in patients with RA was accounted for almost entirely by excess deaths following myocardial infarction. The adjusted ORs for cardiovascular death in RA after myocardial infarction and stroke were 1.9 (95% CI 1.3–2.7) and 1.2 (95% CI 0.7–2.0), respectively.

Conclusion

RA patients have a substantially increased risk of 30‐day case fatality following myocardial infarction, but not stroke, compared with non‐RA patients. This higher case fatality rate is likely to contribute to the observed overall excess of cardiovascular deaths in RA populations.
Inflammatory cytokine regulation of transgene expression in human fibroblast‐like synoviocytes infected with adeno‐associated virus
Authors: Traister Russell S. , Fabre Sylvie , Wang Zhong , Xiao Xiao , Hirsch Raphael
Published: June 2006

Objective

An ideal gene transfer vector for chronic inflammatory diseases such as rheumatoid arthritis (RA) would provide local transgene expression only when the disease is active. To determine whether adeno‐associated virus (AAV) possesses this ability, the effects of inflammatory cytokines on transgene expression were evaluated in human RA fibroblast‐like synoviocytes (FLS).

Methods

Human FLS were infected with AAV in the presence or absence of inflammatory cytokines or synovial fluid obtained from patients with RA. Transgene expression was monitored by either enzyme‐linked immunosorbent assay or flow cytometry. Transgene messenger RNA (mRNA) was measured by real‐time quantitative reverse transcription–polymerase chain reaction.

Results

Inflammatory cytokines increased transgene expression in FLS by up to 60‐fold. Synovial fluid from patients with RA, but not from patients without arthritis, was also able to increase expression in synoviocytes. Protein expression correlated with transgene mRNA levels. The enhanced expression required the continued presence of cytokines because, upon removal, transgene expression returned to baseline levels. Expression could be repeatedly reinduced by reexposure to cytokines. The effect was not promoter specific and was demonstrated to be phosphatidylinositol 3‐kinase–dependent.

Conclusion

These results suggest that expression of a therapeutic transgene can be controlled by the presence of inflammation following AAV gene transfer, making it an attractive vector for chronic inflammatory diseases such as RA.
Effects of interleukin‐1 on calcium signaling and the increase of filamentous actin in isolated and in situ articular chondrocytes
Authors: Pritchard Scott , Guilak Farshid
Published: June 2006

Objective

To determine whether interleukin‐1 (IL‐1) initiates transient changes in the intracellular concentration of [Ca2+]i and the organization of filamentous actin (F‐actin) in articular chondrocytes.

Methods

Articular chondrocytes within cartilage explants and enzymatically isolated chondrocytes were loaded with Ca2+‐sensitive fluorescence indicators, and [Ca2+]i was measured using confocal fluorescence ratio imaging during exposure to 10 ng/ml IL‐1α. Inhibitors of Ca2+ mobilization (Ca2+‐free medium, thapsigargin [inhibitor of Ca‐ATPases], U73122 [inhibitor of phospholipase C], and pertussis toxin [inhibitor of G proteins]) were used to determine the mechanisms of increased [Ca2+]i. Cellular F‐actin was quantified using fluorescently labeled phalloidin. Toxin B was used to determine the role of the Rho family of small GTPases in F‐actin reorganization.

Results

In isolated cells on glass and in in situ chondrocytes within explants, exposure to IL‐1 induced a transient peak in [Ca2+]i that was generally followed by a series of decaying oscillations. Thapsigargin, U73122, and pertussis toxin inhibited the percentage of cells responding to IL‐1. IL‐1 increased F‐actin content in chondrocytes in a manner that was inhibited by toxin B.

Conclusion

Both isolated and in situ chondrocytes respond to IL‐1 with transient increases in [Ca2+]i via intracellular Ca2+ release mediated by the phospholipase C and inositol trisphosphate pathways. The influx of Ca2+ from the extracellular space and the activation of G protein–coupled receptors also appear to contribute to these mechanisms. These findings suggest that Ca2+ mobilization may be one of the first signaling events in the response of chondrocytes to IL‐1.
Abnormal differentiation of memory T cells in systemic lupus erythematosus
Authors: Fritsch Ruth D. , Shen Xinglei , Illei Gabor G. , Yarboro Cheryl H. , Prussin Calman , Hathcock Karen S. , Hodes Richard J. , Lipsky Peter E.
Published: June 2006

Objective

The chemokine receptor CCR7 and the tumor necrosis factor receptor family member CD27 define 3 distinct, progressively more differentiated maturational stages of CD4 memory subpopulations in healthy individuals: the CCR7+,CD27+, the CCR7−, CD27+, and the CCR7−,CD27− populations. The goal of this study was to examine maturational disturbances in CD4 T cell differentiation in systemic lupus erythematosus (SLE), using these phenotypic markers.

Methods

Phenotypic analysis by flow cytometry, in vitro stimulation experiments, telomere length measurement, and determination of inducible telomerase were carried out.

Results

In SLE patients, significant increases of CCR7−,CD27− and CCR7−,CD27+ and a reduction of CCR7+,CD27+ CD4 memory T cells were found. In vitro stimulation of SLE T cells showed a stepwise differentiation from naive to CCR7+,CD27+ to CCR7−,CD27+ to CCR7−,CD27−; telomere length and inducible telomerase decreased in these subsets in the same progressive sequence. The in vitro proliferative response of these populations progressively declined as their susceptibility to apoptosis increased. Interestingly, a significant reduction in inducible telomerase was noted in SLE naive and CCR7+,CD27+ CD4+ memory T cells. Additionally, SLE CCR7−,CD27+ and CCR7−, CD27− CD4 memory T cells proliferated poorly in response to in vitro stimulation and underwent significantly more apoptosis than their normal counterparts. Finally, expression of CXCR4 was significantly reduced in all SLE subsets compared with normal.

Conclusion

Together these data indicate an increased degree of in vivo T cell stimulation in SLE, resulting in the accumulation of terminally differentiated memory T cells with a decreased proliferative capacity and an increased tendency to undergo apoptosis upon stimulation.
Anti‐LA/SSB antiidiotypic antibodies in maternal serum: A marker of low risk for neonatal lupus in an offspring
Authors: Stea Eleni A. , Routsias John G. , Clancy Robert M. , Buyon Jill P. , Moutsopoulos Haralampos M. , Tzioufas Athanasios G.
Published: June 2006

Objective

The anti‐La/SSB response to major B cell epitopes of La/SSB can be blocked by an active idiotypic/antiidiotypic network, which can be identified using synthetic complementary epitopes deduced from the sequence of the major B cell epitopes of the molecule. This study evaluated the role of this network in pregnant women with anti‐Ro/SSA and/or anti‐La/SSB antibodies in the development of neonatal lupus syndrome (NLS).

Methods

Sixty‐three serum samples collected from anti‐Ro/anti‐La–positive women during pregnancy or within 6 months after delivery were obtained from the Research Registry for Neonatal Lupus and the PR Interval Dexamethasone Evaluation study. These samples, as well as 30 sera from healthy individuals, were tested in a blinded manner by enzyme‐linked immunosorbent assay against synthetic peptides corresponding to major B cell epitopes and complementary epitopes of La/SSB.

Results

Sera from mothers giving birth to a healthy child and having no history of a child with NLS exhibited higher antiidiotypic antibody activity compared with mothers carrying a child with NLS (P < 0.0001) or mothers giving birth to a healthy child but who previously gave birth to a child with NLS (P = 0.0151). Sera from mothers of healthy children, which exhibited no apparent epitope activity against amino acids 349–364, revealed a significantly greater frequency of hidden anti–349–364aa epitope responses, blocked by antiidiotypic antibodies, as compared with sera from women pregnant with an affected child (P = 0.0094).

Conclusion

The presence of antiidiotypic antibodies to autoantibodies against La/SSB may protect the fetus by blocking pathogenic maternal autoantibodies. Testing for these antiidiotypic responses may be useful in predicting a decreased risk of NLS.
Homocysteine levels and disease duration independently correlate with coronary artery calcification in patients with systemic lupus erythematosus
Authors: Von Feldt Joan M. , Scalzi Lisabeth V. , Cucchiara Andrew J. , Morthala Suneetha , Kealey Carmel , Flagg Stephanie D. , Genin Anna , Van Dyke Alison L. , Nackos Eleni , Chander Avantika , Gehrie Erika , Cron Randy Q. , Whitehead Alexander S.
Published: June 2006

Objective

To compare the incidence and extent of coronary artery calcification (CAC) as measured by electron beam computed tomography (EBCT) in patients with systemic lupus erythematosus (SLE) and controls, and to identify variables associated with CAC in patients with SLE.

Methods

Female patients with SLE and matched controls were recruited; EBCT of the coronary arteries was performed, and laboratory values (including the homocysteine concentration, the lipid level, the high‐sensitivity C‐reactive protein [hsCRP] concentration, the glomerular filtration rate [GFR], and the level of soluble CD154 [sCD154]) were determined. For patients, the Systemic Lupus International Collaborating Clinics/American College of Rheumatology Damage Index and the SLE Disease Activity Index scores were recorded. Tests of association between the CAC score and the above‐mentioned variables were performed.

Results

The incidence of CAC was higher in patients with SLE than in controls (P = 0.009), and patients had a higher mean raw CAC (rCAC) score (87.9 versus 9.6 in controls; P = 0.02). In particular, more CAC‐positive patients than CAC‐positive controls had rCAC scores above the 75th percentile (P = 0.003). Among both patients and controls, those with CAC were ∼10 years older than those without CAC. In addition to age, a significant determinant of positive CAC status in both groups was the number of cardiovascular risk factors. In patients with SLE, CAC was associated with a higher homocysteine concentration, a lower GFR, and longer disease duration. In controls, the total cholesterol level correlated positively with CAC. When multivariate logistic regression methods were applied to candidate explanatory variables, homocysteine concentration, age, and disease duration (but not the levels of sCD154 or hsCRP) contributed significantly to CAC status. The methylenetetrahydrofolate reductase C677T genotype was not a predictor of hyperhomocysteinemia or CAC status.

Conclusion

Among patients with SLE, the homocysteine concentration, the GFR, age, and disease duration were associated with CAC. CAC occurred more frequently and was more extensive in patients with SLE than in controls, suggesting that EBCT could be used to detect premature atherosclerosis in the former group. An elevated homocysteine concentration might identify patients with SLE who are likely to have premature atherosclerosis and who would benefit from evaluation of CAC by EBCT.
Anti‐20S proteasome autoantibodies inhibit proteasome stimulation by proteasome activator PA28
Authors: Brychcy Michael , Kuckelkorn Ulrike , Hausdorf Gert , Egerer Karl , Kloetzel Peter‐M. , Burmester Gerd‐R. , Feist Eugen
Published: June 2006

Objective

The ubiquitin‐proteasome system plays a central role in cellular homeostasis as well as in regulation of the inflammatory and stress responses. However, the occurrence of autoantibodies against 20S proteasome has, to date, been considered to be a nonspecific epiphenomenon in patients with autoimmune disorders. This study was undertaken to analyze the properties of antiproteasome antibodies by investigating their influence on the proteolytic activity of the proteasome complex.

Methods

The 20S proteasome, with or without addition of the proteasome activator (PA28), was preincubated with affinity‐purified human antiproteasome antibodies. Proteolytic activity was estimated using fluorogenic peptides as substrate.

Results

The baseline proteolytic properties of the 20S proteasome core complex were not influenced by the autoantibodies in vitro. In contrast, all human antiproteasome antibodies analyzed efficiently blocked the enhanced proteasomal substrate cleavage provided by PA28. A similar influence of proteasome activation was observed upon preincubation with affinity‐purified sheep polyclonal or mouse monoclonal antiproteasome antibody, whereas human immunoglobulin controls exhibited no effect.

Conclusion

Autoantibodies against 20S proteasomes are able to block proteasome activation by PA28, binding to their native antigen in vitro. Antibody targeting of the interaction between 20S proteasome and PA28 represents a novel mechanism of proteasome inhibition.
Solvent‐induced lysozyme gels: Effects of system composition and temperature on structural and dynamic characteristics
Authors: da Silva Marcelo A. , Farhat Imad A. , Arêas Elizabeth P. G. , Mitchell John R.
Published: June 2006

The gelation process of lysozyme in water/tetramethylurea in the presence of salt was investigated as a function of temperature and system composition by rheology, infrared spectroscopy, and microcalorimetry. Times and temperatures of gelation were determined from the variation of the storage (G′) and loss (G′′) moduli. It was found that gelation times follow exponential decays with both protein and tetramethylurea (TMU) concentrations and with temperature. The activation energy for the overall process shows a linear dependence on TMU mass fraction. A strongly increased β‐sheet content and reduced α‐helix occur with the increase of TMU concentration in the binary solvent. Also, a linear decrease of lysozyme denaturation temperature and enthalpy on TMU concentration is found for the TMU mass fraction up to 0.5, above which no denaturation signal can be detected. © 2006 Wiley Periodicals, Inc. Biopolymers 83: 443–454, 2006

This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com
Quantification of astaxanthin in shrimp waste hydrolysate by HPLC
Authors: López‐Cervantes J. , Sánchez‐Machado D. I. , Gutiérrez‐Coronado M. A. , Ríos‐Vázquez N. J.
Published: June 2006

In the present study, a simple and rapid reversed‐phase HPLC method for the determination of astaxanthin in shrimp waste hydrolysate has been developed and validated. The analytical procedure involves the direct extraction of astaxanthin from the lipid fraction with methanol. The analytical column, SS Exil ODS, was operated at 25C. The mobile phase consisted of a mixture of water:methanol:dichloromethane:acetonitrile (4.5:28:22:45.5 v/v/v/v) at a flow rate of 1.0 mL/min. Detection and identification were performed using a photodiode array detector (λdetection = 476 nm). The proposed HPLC method showed adequate linearity, repeatability and accuracy. Copyright © 2006 John Wiley & Sons, Ltd.
Photoinduced Electron Transfer in α‐Cyclodextrin‐Based Supramolecular Dyads: A Free‐Energy‐Dependence Study
Authors: Balan Bijitha , Gopidas Karical R.
Published: June 2006

Photoinduced electron transfer (PET) between α‐cyclodextrin‐appended pyrene (PYCD) and a few acceptor molecules was studied in aqueous solutions. The pyrene moiety in PYCD is located above the narrower rim of the α‐CD and is fully exposed to water. The acceptors are monocyclic organic molecules and, upon dissolution in water in the presence of PYCD, a fraction of the donor–acceptor systems is present as supramolecular dyads and the remaining fraction as free molecules. Free‐energy‐dependence studies showed that electron transfer in the supramolecular dyads follows the Marcus equation. The donor–acceptor coupling and the reorganization energy were determined from fits of the data to the Marcus equation. The electronic coupling was found to be similar to those reported for hydrogen‐bonded systems. It appears that the actual λout values are somewhat lower than values calculated with the continuum model. The experimental design has also allowed, for the first time, a visual demonstration of the inverted region on the basis of the raw fluorescence lifetime data.
Assembly‐Controlled Biocompatible Interface on a Microchip: Strategy to Highly Efficient Proteolysis
Authors: Liu Yun , Zhong Wei , Meng Sheng , Kong Jilie , Lu Haojie , Yang Pengyuan , Girault Hubert H. , Liu Baohong
Published: June 2006

A biocompatible interface was constructed on a microchip by using the layer‐by‐layer (LBL) assembly of charged polysaccharides incorporating proteases for highly efficient proteolysis. The controlled assembly of natural polyelectrolytes and the enzyme‐adsorption step were monitored by using a quartz‐crystal microbalance and atomic force microscopy (AFM). Such a multilayer‐assembled membrane provides a biocompatible interconnected network with high enzyme‐loading capacity. The maximum digestion rate of the adsorbed trypsin in a microchannel was significantly accelerated to 1600 mM min−1 μg−1, compared with the tryptic digestion in solution. Based on the Langmuir isotherm model, the thermodynamic constant of adsorption K was calculated to be 1.6×105 M−1 and the maximum adsorption loading Γmax was 3.6×10−6 mol m−2, 30 times more than a monolayer of trypsin on the native surface. The tunable interface containing trypsin was employed to construct a microchip reactor for digestion of femtomoles of proteins and the produced peptides were analyzed by MALDI‐TOF mass spectroscopy. The efficient on‐chip proteolysis was obtained within a few seconds, and the identification of biological samples was feasible.
Flexibility of Inorganic Tennis Ball Structures Inducing Anion Selectivity
Authors: Kim Ki‐Hyun , Park Jung Su , Kang Tae Yi , Oh Kyungeun , Seo Mi‐Sook , Sohn Youn Soo , Jun Moo‐Jin , Nam Wonwoo , Kim Kwan Mook
Published: June 2006

Inorganic tennis balls (ITBs), [[{Pt(betmp)(dach)}2Cu]2(X)][X]3 (in which X=ClO4− (3), NO3− (4), Cl− (5) and Br− (6); dach=trans‐1,2‐diaminocyclohexane and betmp=bisethylthiomethylidenepropanedioate) and [[{Pt(dteym)(dach)}2Cu]2(PF6)][PF6]3 (7; dteym=1,3‐dithiepane‐2‐ylidenemalonate), were prepared as crystals. Investigation of their X‐ray crystal structures revealed that shapes of the cavities in ITBs show significant distortions that depend on the properties of the encapsulated anions. The Cu⋅⋅⋅Cu* distance was observed to be longest in 7 and shortest in 5, the difference between them being 2.05 Å. The flexibility of cavity structures of ITBs makes it possible to encapsulate various anions inside the cavity, while their distortions may be a reason for the difference in the encapsulating ability for anions, that is, anion selectivity. Especially, the distortions observed in 7 are so severe that the encapsulating ability of the cavity for PF6− is very low compared to other anions. The shapes of ITBs with ClO4− and BF4− ions inside their cavities are very similar; however, ClO4− is encapsulated by the cavity better than BF4−, which is explicable by the difference of metal–anion interactions. This structural study on ITBs gives a clue to the origin of the anion selectivity of the cavity in ITBs previously investigated by 19F NMR spectroscopy of the ITBs in methanol.
o‐DPPB‐Directed Copper‐Mediated and ‐Catalyzed Allylic Substitution with Grignard Reagents
Authors: Demel Peter , Keller Manfred , Breit Bernhard
Published: June 2006

The ortho‐diphenylphosphanylbenzoyl (o‐DPPB) group was explored as a directing leaving group in copper‐mediated and copper‐catalyzed allylic substitution with Grignard reagents. Complete control of chemo‐, regio‐ and stereoselectivity with complete syn‐1,3‐chirality transfer was observed as a result of the directed nature of the reaction. No excess of organometallic reagent is required and the directing group can be recovered quantitatively. Coordination studies in the solid state and in solution have shown that two substrates are bound via the phosphine function of the directing group at copper. Dynamic NMR experiments in solution are in agreement with a ligand‐exchange process at copper, a prerequisite for the development of a substoichiometric process.
S‐Thiazolinyl (STaz) Glycosides as Versatile Building Blocks for Convergent Selective, Chemoselective, and Orthogonal Oligosaccharide Synthesis
Authors: Pornsuriyasak Papapida , Demchenko Alexei V.
Published: June 2006

In the aim of developing new procedures for efficient oligosaccharide assembly, a range of S‐thiazolinyl (STaz) glycosides have been synthesized. These novel derivatives were evaluated against a variety of reaction conditions and were shown to be capable of being chemoselectively activated in the armed–disarmed fashion. Moreover, the S‐thiazolinyl moiety exhibited a remarkable propensity for selective activation over other common leaving groups. Conversely, a variety of leaving groups could be selectively activated over the STaz moiety, which, in turn, allowed STaz/S‐ethyl and STaz/S‐phenyl orthogonal approaches. To demonstrate versatility of novel STaz derivatives, a number of oligosaccharide targets have been synthesized in a convergent selective, orthogonal, and chemoselective fashion.
Regio‐ and Stereoselective Palladium‐Pincer Complex Catalyzed Allylation of Sulfonylimines with Trifluoro(allyl)borates and Allylstannanes: A Combined Experimental and Theoretical Study
Authors: Wallner Olov A. , Szabó Kálmán J.
Published: June 2006

Regio‐ and stereoselective palladium‐pincer complex catalyzed allylation of sulfonylimines has been performed by using substituted trifluoro(allyl)borates and trimethylallylstannanes. The reactions provide the corresponding branched allylic products with excellent regioselectivity. The stereoselectivity of these processes is very high when trifluoro(cinnamyl)borate and trimethyl cinnamyl stannane are employed as allylic precursors; however, the reaction with trifluoro(crotyl)borate results in poor stereoselectivity. The major diastereomer formed in these reactions was the syn isomer, while the (previously reported) reactions with aldehyde electrophiles afforded the anti products, indicating that the mechanism of the stereoselection is dependent on the applied electrophile. Therefore, we have studied the mechanistic aspects of the allylation reactions by experimental studies and DFT modeling. The experimental mechanistic studies have clearly shown that potassium trifluoro(allyl)borate undergoes transmetallation with palladium‐pincer complex 1 a affording an η1‐allylpalladium‐pincer complex (1 e). The mechanism of the transfer of the allyl moiety from palladium to the sulfonylimine substrate was studied by DFT calculations at the B3PW91/LANL2DZ+P level of theory. These calculations have shown that the electrophilic substitution of sulfonylimines proceeds in a one‐step process with a relatively low activation energy. The topology of the potential energy surface in the vicinity of the transition‐state structure proved to be rather complicated as nine different geometries with similar energies were located as first order saddle points. Our studies have also shown that the high stereoselectivity with cinnamyl metal reagents stems from steric interactions in the TS structure of the allylation reaction. In addition, these studies have revealed that the mechanism of the stereoselection in the allylation of aldehydes and sulfonylimines is fundamentally different.
Deep Blue Mixed‐Valent PtIIIPtIIIPtII Complex [Pt3Br2(μ‐pz)6] (pz=Pyrazolate) Showing Valence‐Detrapping Behavior in Solution
Authors: Umakoshi Keisuke , Kojima Takashi , Kim Yong Hun , Onishi Masayoshi , Nakao Yoshihide , Sakaki Shigeyoshi
Published: June 2006

The oxidation of the pyrazolate bridged cyclic PtII trimer, [Pt3(μ‐pz)6] (1), in the presence of bromide ion gave a deep blue mixed‐valent PtII,III,III complex, [Pt3Br2(μ‐pz)6] (2). The structural analysis of 2 disclosed that the complex has localized PtPt bond. Our theoretical calculations revealed that the HOMO and LUMO of Pt3II,III,III species mainly consists of (dσ–dσ) and (dσ–dσ)* orbitals, respectively, and the origin of deep blue color of the bromo complex, 2, arises from the (dσ–dσ)→(dσ–dσ)* transition. Unique fluxional behavior was observed due to valence‐detrapping of 2 in solution. The activation parameters of the valence‐detrapping of 2 obtained by Eyring analyses were ΔH≠=37(2) kJ mol−1 and ΔS≠=−67(7) J mol−1 K−1.
Influence of obesity on biochemical and clinical failure after external‐beam radiotherapy for localized prostate cancer
Authors: Strom Sara S. , Kamat Ashish M. , Gruschkus Stephen K. , Gu Yun , Wen Sijin , Cheung Min Rex , Pisters Louis L. , Lee Andrew K. , Rosser Charles J. , Kuban Deborah A.
Published: June 2006

BACKGROUND.

Several reports have shown that obesity is associated with increased risk of biochemical failure after radical prostatectomy. However, limited information is available regarding the impact of obesity on prostate cancer progression after radiotherapy. The current study sought to determine whether obesity was an independent predictor of biochemical failure (BF) and clinical recurrence (CF) among patients treated with external‐beam radiotherapy (EBRT).

METHODS.

A retrospective analysis was performed on 873 patients receiving EBRT as the sole treatment for localized prostate cancer between 1988 and 2001. The Kaplan–Meier method, log‐rank test, and Cox proportional hazards analyses were performed.

RESULTS.

Of the 873 patients, 18% were mildly obese and 5% were moderately to severely obese. Obesity was related to younger age at diagnosis (P < .001), more recent year of diagnosis (P = .03), and race (P = .03), with African‐American men having the highest obesity rates. During a mean follow‐up of 96 months, 295 patients experienced BF and 127 had CF. On multivariate analysis, controlling for clinical and treatment characteristics, increased body mass index (BMI) significantly predicted BF (hazards ratio [HR] = 1.04; 95% confidence interval [95% CI], 1.02–1.07) with a positive trend by BMI category (P = .001). Similar results were found when the outcome was CF; BMI remained an independent predictor of progression (HR = 1.05; 95% CI, 1.01–1.09), with a statistically significant trend by increased BMI category (P = .03).

CONCLUSIONS.

The current findings validate the important role of obesity, not only on BF but also on CF, and suggest a link to the biologic basis of tumor progression that can be therapeutically exploited. Cancer 2006. © 2006 American Cancer Society.
Object comparison using PDE‐based wave metric on cellular neural networks
Authors: Szatmári István
Published: June 2006

The paper investigates PDE‐based dynamic phenomena for comparing objects and introduces a spatio‐temporal non‐linear wave metric. This metric is capable of comparing both binary and grey‐scale object pairs in a parallel way. Spatio‐temporal waves are initialized and controlled to explore the quantitative properties of objects. In addition to spatial data, even ‘hidden’, time‐related information is also extracted and used for evaluating differences and similarities. The detailed analysis of the proposed metric shows that this wave‐based approach can outperform well‐known metrics such as Hausdorff and Hamming metrics in selectivity and sensitivity. The approach in question can be efficiently implemented on massively parallel architectures, e.g. on Cellular Neural/Non‐linear Networks (CNN), providing solutions either for real time applications. Copyright © 2006 John Wiley & Sons, Ltd.
Computational auditory scene analysis in cellular wave computing framework
Authors: Fodróczi Zoltán , Radványi András
Published: June 2006

Extracting substantive auditory objects from an auditory mixture is a widely studied and difficult problem in auditory research. Computational auditory scene analysis (CASA) aims at extracting objects in the frequency domain, based on a set of psychoacoustic grouping procedures. To mimic some aspects of the human auditory system a new cellular neural/non‐linear network (CNN)‐based library of procedures forming an Auditory Wave Computing Toolkit (AWCT) is presented here. Copyright © 2006 John Wiley & Sons, Ltd.
Emulated digital CNN‐UM solution of partial differential equations
Authors: Nagy Zoltán , Vörösházi Zsolt , Szolgay Péter
Published: June 2006

We present here new cellular neural/non‐linear networks (CNN)‐based emulated digital architectures specifically designed for the solution of different partial differential equations (PDE). The array structure and local connectivity of the CNN paradigm make it a natural framework to describe the behaviour of locally interconnected dynamical systems. Solution of the PDE is carried out by a spatio‐temporal dynamics, which can be computed in real‐time on analogue CNN‐UM chips, but the accuracy of the solution is low. Additionally, solution of PDEs on a CNN‐UM architecture often requires a multi‐layer structure and non‐linear templates which is partially or not supported on the current analogue VLSI CNN‐UM chips. To overcome these obstacles while preserving high computing performance a configurable emulated digital CNN‐UM can be used where the main parameters (accuracy, template size and number of layers) are configurable. Additionally, the symmetry of the finite difference operators makes it possible to specialize the emulated digital CNN‐UM architecture to solve a specific type of PDE, which results in higher performance. Emulated digital CNN‐UM processors use fixed‐point numbers to carry out computations, and by decreasing the precision the speed of the computations can be improved. Hence, a simple algorithm is introduced to determine the optimal fixed‐point precision and maximize computing performance. Copyright © 2006 John Wiley & Sons, Ltd.
3D tactile sensor array processed by CNN‐UM: a fast method for detecting and identifying slippage and twisting motion
Authors: Kis Attila , Kovács Ferenc , Szolgay Péter
Published: June 2006

In this paper, we present a fast and efficient technique for detecting and identifying the slippage and twisting motion of touching objects. This kind of action cannot be detected with tactile sensors sensing only the normal (perpendicular) component of the forces acting between surfaces. Our approach utilizes an integrated sensing–processing–actuating system comprising: (1) A 2 × 2 taxel (tactile pixel) array mounted on a two‐fingered robot hand, (2) a 64 × 64 CNN‐UM (Cellular Neural Network‐Universal machine), and (3) a closed‐loop controller. This arrangement, along with the proper analogic algorithm, allows detection and the control of the tactile event. It is essential to know and comprehend the forces between contact surfaces and the related 3D pressure fields is essential in many robotic applications discussed in the paper. Copyright © 2006 John Wiley & Sons, Ltd.
Dense CMOS implementation of a binary‐programmable cellular neural network
Authors: Flak Jacek , Laiho Mika , Paasio Ari , Halonen Kari
Published: June 2006

An implementation of a cellular neural/non‐linear network (CNN) for processing black‐and‐white (B/W) images is presented in which the template terms are 1‐bit programmable. Such approach leads to a very compact implementation of the coefficient circuits and fast (digital) programming. In this programming scheme, the more complex templates are split into subtasks that are run successively. The structure allows a direct or algorithmic evaluation of the majority of templates proposed for B/W images. The transient mask is utilized in performing the local logic operations as well as in template operations. The proposed architecture is suitable for high‐density implementations. A test structure of a 4 × 4 network has been implemented with a standard digital 0.18‐µm CMOS process. One cell occupies only 155 µm2, making possible the implementations of very large networks on a single chip. The algorithms used for the logic function computations and selected template evaluations are described, and the corresponding measurement results are shown. Copyright © 2006 John Wiley & Sons, Ltd.