bluuebunny/crossref_metadata_2025 huggingface dataset:
Bim deficiency leads to exacerbation and prolongation of joint inflammation in experimental arthritis
Authors: Scatizzi John C. , Bickel Emily , Hutcheson Jack , Haines G. Kenneth , Perlman Harris
Published: September 2006

Objective:

Rheumatoid arthritis (RA) is characterized by hyperplasia of the synovial lining, inflammation, and destruction of cartilage and bone. Since there are only a few detectable cells undergoing apoptosis in the joint, it is possible that a defect in apoptosis may contribute to synovial hyperplasia. This study sought to identify and characterize the direct role of apoptotic regulators in a mouse model of inflammatory arthritis.

Methods

Using a serum transfer model, experimental arthritis was induced in mice lacking the proapoptotic Bcl‐2 family genes Bak (Bak−/−), Bax (Bax−/−), or Bim (Bim−/−), as compared with wild‐type (WT) control mice. Physical examination for edema of the ankles and histopathologic analysis of ankle sections were used to determine the severity of arthritis. The serum and ankles were examined for production of chemokines and cytokines using enzyme‐linked immunosorbent or Luminex‐based assays.

Results

Bim−/− mice displayed increased severity and prolongation of arthritis. In contrast, Bak−/− and Bax−/− mice showed no difference in the severity of arthritis as compared with WT mice. In addition, Bim−/− mice had elevated levels of proinflammatory chemokines and cytokines, decreased joint and serum production of antiinflammatory cytokines, fewer TUNEL‐positive cells, and reduced levels of active caspase 3 as compared with WT mice.

Conclusion

These studies are the first to demonstrate a role for the proapoptotic Bcl‐2 protein Bim in the effector phase of RA. The findings indicate that Bim potentially functions to repress the effector phase of arthritis by regulating the milieu of the joint and serum, and by inducing apoptosis.
Fluctuation in self‐perceived stress and increased risk of flare in patients with lupus nephritis carrying the serotonin receptor 1A –1019 G allele
Authors: Birmingham Daniel J. , Nagaraja H. N. , Rovin Brad H. , Spetie Lacramioara , Zhao Yanxing , Li Xiaobai , Hackshaw Kevin V. , Yu C. Yung , Malarkey William B. , Hebert Lee A.
Published: September 2006

Objective

Stress is believed to be a risk factor for systemic lupus erythematosus (SLE) flare. Two serotonin‐related gene polymorphisms, the serotonin receptor 1A (5‐HT1A) polymorphism at –1019C>G and the serotonin transporter LS polymorphism, have been reported to affect stress‐related behaviors. The purpose of this study was to assess the relationship between self‐perceived stress (SPS), variability in SPS, and the 2 serotonin‐related gene polymorphisms as risk factors for SLE flare.

Methods

Seventy‐seven SLE patients (50 with lupus nephritis) were evaluated every 2 months (mean ± SD total followup 18.5 ± 8.5 months), and patients recorded their daily SPS levels (0–10 scale). Values for mean SPS and coefficient of variation (CV) for SPS were calculated from the 60‐day block of daily measurements between study visits. Serotonin‐related gene polymorphism genotypes were determined by polymerase chain reaction–based methods.

Results

Of the 77 patients, 53 experienced 80 flares of SLE (32 renal flares) based on prespecified criteria. Multivariate analysis revealed that whereas neither the serotonin‐related gene polymorphisms nor the mean SPS was predictive of an SLE flare, an increased CV for SPS was predictive (P = 0.0031). Interaction between the CV for SPS and the 5‐HT1A –1019C>G polymorphism was also found to be a predictor of SLE flare (P = 0.0039). Subset analysis revealed that only in lupus nephritis patients were increasing CVs for SPS (P = 0.0002) and the interaction between CVs for SPS and 5‐HT1A (P < 0.0001) predictive of a flare. Odds ratio curves demonstrated that the predictive effect of increasing CVs for SPS required the presence of the 5‐HT1A –1019 G allele, but appeared to be independent of the G allele number.

Conclusion

Fluctuation in the level of SPS is a risk factor for the onset of flare in SLE patients with major renal manifestations when it occurs on the background of a stress‐related susceptibility gene (the 5‐HT1A –1019 G allele).
Effect of hormone therapy on risk of hip and knee joint replacement in the women's health initiative
Authors: Cirillo Dominic J. , Wallace Robert B. , Wu LieLing , Yood Robert A.
Published: September 2006

Objective

To determine the effect of hormone therapy on arthroplasty rates.

Methods

We examined data from the Women's Health Initiative placebo‐controlled, double‐blind, randomized trials. Community‐dwelling women ages 50–79 years were enrolled at 40 US clinics. Women with prior arthroplasty were excluded, yielding a sample size of 26,321 subjects. Women who had had hysterectomies (n = 10,272) were randomly assigned to receive 0.625 mg/day conjugated equine estrogens (n = 5,076), or placebo (n = 5,196), with a mean followup of 7.1 years. Those who had not had hysterectomies (n = 16,049) were randomly assigned to receive estrogen plus progestin (n = 8,240), given as 0.625 mg/day conjugated equine estrogens plus 2.5 mg/day medroxyprogesterone acetate, or placebo (n = 7,809), with a mean followup of 5.6 years. Participants reported hospitalizations, and arthroplasties were identified by procedure codes. Arthroplasties due to hip fracture were censored. Cox proportional hazards regression was used to assess hazard ratios (HRs) and 95% confidence intervals (95% CIs) using intent‐to‐treat methods and outcome of time to first procedure.

Results

In the estrogen‐alone trial, women receiving hormone therapy had significantly lower rates of any arthroplasty (HR 0.84 [95% CI 0.70–1.00], P = 0.05). However, this effect was borderline statistically significant for hip arthroplasty (HR 0.73 [95% CI 0.52–1.03], P = 0.07), and not significant for knee arthroplasty (HR 0.87 [95% CI 0.71–1.07], P = 0.19). In the estrogen‐plus‐progestin trial, there was no association for total arthroplasty (HR 0.99 [95% CI 0.82–1.20], P = 0.92) or for individual hip (HR 1.14 [95% CI 0.83–1.57], P = 0.41) or knee (HR 0.91 [95% CI 0.72–1.15], P = 0.41) arthroplasties.

Conclusion

These data suggest that hormone therapy may influence joint health, but this observed decrease in risk may be limited to unopposed estrogen and may possibly be more important in hip than in knee osteoarthritis.
CTLA‐4IG suppresses reactive oxygen species by preventing synovial adherent cell–induced inactivation of rap1, a ras family GTPASE mediator of oxidative stress in rheumatoid arthritis T cells
Authors: Remans P. H. J. , Wijbrandts C. A. , Sanders M. E. , Toes R. E. , Breedveld F. C. , Tak P. P. , van Laar J. M. , Reedquist K. A.
Published: September 2006

Objective

Oxidative stress contributes to the inflammatory properties of rheumatoid arthritis (RA) synovial T lymphocytes. This study was undertaken to investigate the mechanisms leading to production of reactive oxygen species (ROS) and oxidative stress in RA synovial T lymphocytes.

Methods

ROS production in T lymphocytes from the peripheral blood (PB) of healthy donors and from the PB and synovial fluid (SF) of RA patients was measured by ROS‐dependent fluorescence of 6‐carboxy‐2′,7′‐dichlorofluorescein. Rap1 GTPase activation was assessed by activation‐specific probe precipitation. Proliferation of RA PB and SF T lymphocytes was assayed by 3H‐thymidine incorporation. In some experiments, RA PB T cells were preincubated with autologous SF or with PB or SF adherent cells. Experiments were performed in the absence or presence of transwell membranes or CTLA‐4Ig fusion proteins. Short‐ and long‐term stimulations of healthy donor PB T lymphocytes were performed with inflammatory cytokines, in the absence or presence of activating anti‐CD28 antibodies.

Results

T lymphocyte ROS production and Rap1 inactivation were mediated by cell–cell contact with RA synovial adherent cells, and this correlated with T cell mitogenic hyporesponsiveness. CTLA4‐Ig blockade of synovial adherent cell signaling to CD28 T cells reversed the inhibition of Rap1 activity and prevented induction of ROS. Introduction of active RapV12 into T cells also prevented induction of ROS production. Coincubation of T cells with stimulating anti‐CD28 antibodies and inflammatory cytokines synergistically increased T cell ROS production.

Conclusion

Cell–cell contact between T cells and RA synovial adherent cells mediates Rap1 inactivation and subsequent ROS production in T lymphocytes following exposure to inflammatory cytokines. This process can be blocked by CTLA4‐Ig fusion protein.
Tetraspanin CD151 is expressed in osteoarthritic cartilage and is involved in pericellular activation of pro–matrix metalloproteinase 7 in osteoarthritic chondrocytes
Authors: Fujita Yoshinari , Shiomi Takayuki , Yanagimoto Shigeru , Matsumoto Hideo , Toyama Yoshiaki , Okada Yasunori
Published: September 2006

Objective

The proenzyme of matrix metalloproteinase 7 (proMMP‐7), which can degrade various extracellular matrix (ECM) and non‐ECM molecules after being activated, is overexpressed in osteoarthritic (OA) articular cartilage, but the process of its activation in the cartilage remains unknown. The present study was undertaken to investigate the expression of tetraspanin CD151 in OA cartilage and its involvement in proMMP‐7 activation.

Methods

The expression of CD151 in articular cartilage was examined by reverse transcription–polymerase chain reaction (RT‐PCR), real‐time PCR, immunohistochemistry, in situ hybridization, and immunoblotting. Chondrocytes were used to study the interaction between CD151 and proMMP‐7, and activation of proMMP‐7.

Results

RT‐PCR revealed expression of CD151 messenger RNA in all OA cartilage samples, but in only 30% of normal control cartilage samples. Immunohistochemistry and in situ hybridization findings indicated that CD151 was coexpressed with proMMP‐7 in chondrocytes, mainly in the superficial and transitional zones of OA cartilage. CD151 immunoreactivity directly correlated with the Mankin score (r = 0.757, P < 0.0001 [n = 30]) and the degree of chondrocyte cloning (r = 0.83, P < 0.0001 [n = 30]) in the cartilage samples. Complexes CD151 and proMMP‐7 and their colocalization on the cell membranes were demonstrated by immunoprecipitation and double fluorescence immunostaining of the OA chondrocytes. In situ zymography indicated that chondrocytes exhibit pericellular proteolytic activity, which was abolished by treatment with MMP inhibitors, anti–MMP‐7 antibody, or anti‐CD151 antibody.

Conclusion

These data demonstrate that CD151 is overexpressed in OA cartilage and suggest that CD151 plays a role in the pericellular activation of proMMP‐7, leading to cartilage destruction and/or chondrocyte cloning.
A prospective population‐based study of the predictors of undergoing total joint arthroplasty
Authors: Hawker Gillian A. , Guan Jun , Croxford Ruth , Coyte Peter C. , Glazier Richard H. , Harvey Bart J. , Wright James G. , Williams Jack I. , Badley Elizabeth M.
Published: September 2006

Objective

To examine prospectively the predictors of time to total joint arthroplasty (TJA).

Methods

This was a prospective cohort study with a median followup time of 6.1 years. We included participants from an existing population‐based cohort of 2,128 individuals, ages 55 years and older with disabling hip and/or knee arthritis and no prior TJA, from 2 regions of Ontario, Canada, 1 urban with low TJA rates and 1 rural with high rates. The main outcome measure was the occurrence of a TJA based on procedure codes in the hospital discharge abstract database.

Results

At baseline, the mean age of the patients was 71.5 years, 67.9% had a high school education or higher, 73.4% were women, the mean arthritis severity (Western Ontario and McMaster Universities Osteoarthritis Index [WOMAC]) score was 41.1 (maximum possible score 100), and 20.0% were willing to consider TJA. Greater probability of undergoing TJA was associated with higher (worse) baseline WOMAC scores (hazard ratio [HR] 1.22 per 10‐unit increase, P < 0.001), age (compared with age ≤62 years, the HR increased to 1.57 for 63–68 years, 1.46 for 69–74 years, and 1.51 for 75–81 years, and fell to 0.44 for ≥82 years; P < 0.05 for all), better health (HR 1.14 per 10‐unit increase in Short Form 36 general health survey score, P < 0.001), and willingness to consider TJA (HR 4.92, P < 0.001). When willingness was excluded from the model, education level, but not sex or income, became a significant predictor of TJA receipt.

Conclusion

Willingness to consider TJA was the strongest predictor of the time to first TJA. Given that previous research indicates that willingness is largely explained by perceptions of the indications for and risks associated with TJA and not disease severity, this finding supports the need for population education about arthritis treatments, including TJA.
The –786C/T single‐nucleotide polymorphism in the promoter of the gene for endothelial nitric oxide synthase: Insensitivity to physiologic stimuli as a risk factor for rheumatoid arthritis
Authors: Melchers Inga , Blaschke Sabine , Hecker Markus , Cattaruzza Marco
Published: September 2006

Objective

Shear stress is the main physiologic stimulus for the expression of NOS3, the gene for human endothelial nitric oxide synthase. Interestingly, a promoter variant of the NOS3 gene, the –786C variant, is insensitive to shear stress, and individuals homozygous for this single‐nucleotide polymorphism (SNP) have an increased risk of developing coronary artery disease. The cytokine interleukin‐10 (IL‐10) is also capable of up‐regulating endothelial NOS3 expression through binding of the transcription factor STAT‐3 to a nearby promoter sequence. The aim of this study was to explore the possibility that the –786C variant of the NOS3 gene is also insensitive to IL‐10 and that individuals with the –786C/C genotype are more prone to developing rheumatoid arthritis (RA).

Methods

Endothelial cells were isolated from human umbilical cord veins, clonally expanded, and analyzed for NOS3 and IL‐12 expression by real‐time quantitative reverse transcription–polymerase chain reaction and enzyme‐linked immunosorbent assay. Umbilical cord arteries and blood samples from RA patients were genotyped for the –786C/T SNP of the NOS3gene.

Results

In contrast to cells of other genotypes, endothelial cells of the –786C/C genotype did not reveal an increase in NOS3 expression upon exposure to IL‐10, and the cytokine failed to suppress IL‐12 expression upon stimulation of CD40. Preincubation of these cells with a 16‐mer C‐type decoy oligonucleotide fully reconstituted the defective IL‐10–induced suppression of IL‐12 synthesis. The frequency of the –786C/C genotype was significantly higher in the 596 RA patients than in the general population (19.1% versus 12.1%; P < 0.0001).

Conclusion

Individuals with the –786C/C genotype have an increased risk of developing RA. This may be explained by the IL‐10 insensitivity of the C‐type NOS3 gene promoter and the resulting failure to subdue CD40‐mediated proinflammatory gene expression.
Low blood concentration of hydroxychloroquine is a marker for and predictor of disease exacerbations in patients with systemic lupus erythematosus
Authors: Costedoat‐Chalumeau Nathalie , Amoura Zahir , Hulot Jean‐Sébastien , Hammoud Hala Abou , Aymard Guy , Cacoub Patrice , Francès Camille , Wechsler Bertrand , Huong Du Le Thi , Ghillani Pascale , Musset Lucile , Lechat Philippe , Piette Jean‐Charles
Published: September 2006

Objective

To study the possible relationship between whole‐blood hydroxychloroquine (HCQ) concentrations and clinical efficacy of HCQ in patients with systemic lupus erythematosus (SLE).

Methods

Whole‐blood HCQ concentrations were measured, under blinded conditions, in 143 unselected patients with SLE who had been receiving HCQ 400 mg daily for at least 6 months. The relationship of these concentrations to current disease activity and to subsequent exacerbations during 6 months of followup was investigated.

Results

At baseline, 23 patients had active disease (mean ± SD SLE Disease Activity Index 12.4 ± 7.5). The mean whole‐blood HCQ concentration in this group was significantly lower than that in the 120 patients with inactive disease (694 ± 448 ng/ml versus 1,079 ± 526 ng/ml; P = 0.001). Among the 120 patients who had inactive disease at baseline, the mean HCQ concentration at baseline in the 14 (12%) who had disease exacerbations during followup was significantly lower than that in the patients whose disease remained inactive. Multivariate logistic regression showed that the HCQ concentration was the only predictor of exacerbation (odds ratio 0.4 [95% confidence interval 0.18–0.85], P = 0.01). Receiver operating characteristic curve analysis showed that a whole‐blood HCQ concentration cutoff of 1,000 ng/ml had a negative predictive value of 96% for exacerbation during followup.

Conclusion

Low whole‐blood HCQ concentrations are associated with SLE disease activity and are a strong predictor of disease exacerbation. Regular drug assaying and individual tailoring of treatment might help to improve the efficacy of HCQ treatment in patients with SLE.
Oncostatin M induces angiogenesis and cartilage degradation in rheumatoid arthritis synovial tissue and human cartilage cocultures
Authors: Fearon Ursula , Mullan Ronan , Markham Trevor , Connolly Mary , Sullivan Shane , Poole A. Robin , FitzGerald Oliver , Bresnihan Barry , Veale Douglas J.
Published: September 2006

Objective

To investigate the role of oncostatin M (OSM) in cell adhesion, angiogenesis, and matrix degradation in rheumatoid arthritis (RA) synovial tissue and normal human cartilage.

Methods

Human dermal microvascular endothelial cell (HDMEC) and RA synovial fibroblast (RASF) proliferation and intercellular adhesion molecule 1 (ICAM‐1) and vascular cell adhesion molecule 1 (VCAM‐1) expression were assessed by a bromodeoxyuridine proliferation assay and flow cytometry. HDMEC tubule formation and migration were assessed by Matrigel culture and migration assay. Production of matrix metalloproteinase (MMP) and tissue inhibitor of metalloproteinases 1 (TIMP‐1) in RA synovial explants, and proteoglycan/glycosaminoglycan (GAG) release, vascular endothelial growth factor (VEGF), and angiopoietin 2 production from RASF/normal cartilage cocultures were assessed by enzyme‐linked immunosorbent assay and immunohistology.

Results

HDMEC/RASF proliferation was induced by OSM and interleukin‐1β (IL‐1β), alone and in combination. OSM enhanced cell surface expression of ICAM‐1, but not VCAM‐1, on endothelial cells and RASFs. OSM increased endothelial cell tubule formation and migration. In RA synovial explants, OSM induced production of MMP‐1 and TIMP‐1. When OSM was combined with IL‐1β, however, the MMP‐1:TIMP‐1 ratio was significantly increased. OSM potentiated IL‐1β–induced MMP‐1 and MMP‐13 expression in normal human cartilage/RASF cocultures, resulting in a significant increase in the MMP:TIMP ratio. In OSM/IL‐1β– stimulated cocultures, cartilage sections demonstrated significant proteoglycan depletion that was paralleled by a significant increase in GAG release in supernatants. Finally, compared with either cytokine alone, the combination of OSM and IL‐1β significantly induced VEGF production in RASF/cartilage cocultures.

Conclusion

These data suggest that OSM promotes angiogenesis and endothelial cell migration and potentiates the effects of IL‐1β in promoting extracellular matrix turnover and human cartilage degradation. Furthermore, the induction of VEGF in cocultures supports the hypothesis of a link between angiogenesis and cartilage degradation.
Revised British Isles Lupus Assessment Group 2004 index: A reliable tool for assessment of systemic lupus erythematosus activity
Authors: Yee Chee‐Seng , Farewell Vernon , Isenberg David A. , Prabu Athiveeraramapandian , Sokoll Katharina , Teh Lee‐Suan , Rahman Anisur , Bruce Ian N. , Griffiths Bridget , Akil Mohammed , McHugh Neil , D'Cruz David , Khamashta Munther A. , Bowman Simon , Maddison Peter , Zoma Asad , Allen Elizabeth , Gordon Caroline
Published: September 2006

Objective

To test the interrater reliability of the revised British Isles Lupus Assessment Group 2004 (BILAG‐2004) index for the assessment of systemic lupus erythematosus (SLE) activity.

Methods

Patients with SLE were recruited from 11 centers. Two physician raters separately assessed the patients' disease activity using the BILAG‐2004 index in routine clinical practice. Scores ranged from A (for very active disease) to E (for inactivity). Two reliability exercises were performed. Changes were made to the index after the first exercise (E1), and additional training was provided to the raters before the second exercise (E2). E1 and E2 involved 12 and 14 raters, respectively. Interrater reliability was assessed using kappa statistics and intraclass correlation coefficients. Levels of agreement and the extent of major disagreement were also examined. Major disagreement was defined as a score difference between raters of A versus C, D, or E or B versus D or E.

Results

For each exercise, 97 patients were recruited. In E1, the mean age of the patients was 42.3 years (range 18.5–82.2 years), 89.7% were women, and 74.2% were white, 8.2% were Afro‐Caribbean, and 13.4% were South Asian, and in E2, the mean age was 43.7 years (range 17.7–75 years), 90.7% were women, and 68% were white, 15.5% were Afro‐Caribbean, and 11.3% were South Asian. The mean disease duration was 9.4 years (range 0–32.1 years) for patients in E1 and 10 years (range 0–34.8 years) in E2. There was improvement in the interrater reliability and the level of agreement from E1 to E2. Further improvement was achieved after removal of poorly performing items.

Conclusion

The BILAG‐2004 index is a reliable tool to assess SLE activity. The use of a well‐defined glossary and training of raters are essential to ensure the optimal performance of the index.
Matrix metalloproteinase 10 promotion of collagenolysis via procollagenase activation: Implications for cartilage degradation in arthritis
Authors: Barksby H. E. , Milner J. M. , Patterson A. M. , Peake N. J. , Hui W. , Robson T. , Lakey R. , Middleton J. , Cawston T. E. , Richards C. D. , Rowan A. D.
Published: September 2006

Objective

We have previously reported the up‐regulation of matrix metalloproteinase 10 (MMP‐10) following treatment with the procatabolic stimulus of interleukin‐1 (IL‐1) and oncostatin M (OSM) in chondrocytes. Although MMP‐10 is closely related to MMP‐3, little is known about the role of MMP‐10 in cartilage catabolism. The purpose of this study was to determine whether MMP‐10 is expressed in connective tissue cells and to assess how it may contribute to cartilage collagenolysis.

Methods

MMP gene expression was assessed by real‐time polymerase chain reaction using RNA from human articular chondrocytes and synovial fibroblasts stimulated with IL‐1 plus OSM or tumor necrosis factor α (TNFα) plus OSM. Synovial fluid levels of MMP‐10 were determined by specific immunoassay. Recombinant procollagenases were used in activation studies. Immunohistochemistry assessed MMP‐10 expression in diseased joint tissues.

Results

MMP‐10 expression was confirmed in both chondrocytes and synovial fibroblasts following stimulation with either IL‐1 plus OSM or TNFα plus OSM, and MMP‐10 was detected in synovial fluid samples from patients with various arthropathies. Exogenous MMP‐10 significantly enhanced collagenolysis from IL‐1 plus OSM–stimulated cartilage, and MMP‐10 activated proMMP‐1, proMMP‐8, and proMMP‐13. Immunohistochemistry revealed the presence of MMP‐10 in the synovium and cartilage of an IL‐1 plus OSM–induced model of arthritis as well as in samples of diseased human tissues.

Conclusion

We confirm that both synovial fibroblasts and articular chondrocytes express MMP‐10 following treatment with procatabolic stimuli. Furthermore, the detectable levels of synovial fluid MMP‐10 and the histologic detection of this proteinase in diseased joint tissues strongly implicate MMP‐10 in the cartilage degradome during arthritis. The ability of MMP‐10 to superactivate procollagenases that are relevant to cartilage degradation suggests that this activation represents an important mechanism by which this MMP contributes to tissue destruction in arthritis.
Design of Dual‐Emission Chemosensors for Ratiometric Detection of ATP Derivatives
Authors: Ojida Akio , Miyahara Yoshifumi , Wongkongkatep Jirarut , Tamaru Shun‐ichi , Sada Kazuki , Hamachi Itaru
Published: September 2006

Nucleoside pyrophosphate (nucleoside PP) derivatives are widespread in living cells and play pivotal roles in various biological events. We report novel fluorescence chemosensors for nucleoside PPs that make use of coordination chemistry. The chemosensors, which contain two ZnII–dipicolylamine units, bind strongly to nucleoside PPs (Kapp>106 M−1) in aqueous solution and sense them by a dual‐emission change. Detailed fluorescence and UV/Vis spectral studies revealed that the emission changes of the chemosensors upon binding to nucleoside PPs can be ascribed to the loss of coordination between ZnII and the acridine fluorophore. This is a unique sensing system based on the anion‐induced rearrangement of the coordination. Furthermore, we demonstrated the utility of these chemosensors in real‐time monitoring of two important biological processes involving nucleoside PP conversion: the apyrase‐catalyzed hydrolysis of nucleoside PPs and the glycosyl transfer catalyzed by β‐1,4‐galactosyltransferase.
Protein–protein interactions as targets for small molecule drug discovery
Authors: Fry David C.
Published: September 2006

Protein–protein interactions represent a highly populated class of targets for drug discovery. However, such systems present a number of unique challenges. This review presents an analysis of individual protein‐protein interaction systems which have recently yielded success in discovering drug‐like inhibitors. The structural characteristics of the protein binding sites and the attributes of the small molecule ligands are focused upon, in an attempt to derive commonly shared principles that may be of general usefulness in future drug discovery efforts within this target class. © 2006 Wiley Periodicals, Inc. Biopolymers (Pept Sci) 84: 535–552, 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
Application of biological activated carbon as a low pH biofilter medium for gas mixture treatment
Authors: Liang Juan , Chiaw Lawrence Koe Choon , Ning Xiaogang
Published: September 2006

Packing material is a crucial component of a bioreactor as it is the microbial population's habitat. This study assessed potential improvements to current biofiltration processes by investigating use of a novel support medium. Biological activated carbon (BAC) with microorganisms growing on granular activated carbon can produce a novel medium in which both adsorption and biodegradation contribute to pollutants removal. Investigation of carbon characteristics demonstrated that BAC was an ideal packing medium for biofiltration. The application of the novel packing medium for gas mixture treatment was evaluated in a low pH biofilter. Results demonstrated that BAC biofilter obtained high removal efficiency for both H2S and toluene. The removal mechanisms of BAC were investigated after the biofilter operation and it demonstrated that the performance of the BAC system was mainly controlled by the additive contributions of two removal mechanisms—adsorption and biodegradation. This study also indicated the potential for simultaneous treatment of hydrogen sulfide and toluene at low pH condition. Biotechnol. Bioeng. 2007;96:1092–1100. © 2006 Wiley Periodicals, Inc.
Cereal‐based biorefinery development: Integrated enzyme production for cereal flour hydrolysis
Authors: Koutinas A.A. , Arifeen N. , Wang R. , Webb C.
Published: September 2006

Restructuring the traditional fermentation industry into viable biorefineries for the production of fuels, chemicals and plastics is essential in order to replace (petro)chemical processing. This work presents engineering aspects of Aspergillus awamori submerged fermentation for on‐site production of an enzymatic consortium that contains glucoamylase, protease and phosphatase. The crude broth filtrate was used for the production of wheat flour hydrolysates. Improvements on traditional starch hydrolysis carried out in two stages (liquefaction and saccharification) were attempted through integration of unit operations and reduction of processing temperature and reaction duration. An initial increase of temperature to 68°C and a subsequent decrease to 60°C for the rest of the enzymatic hydrolysis resulted in a starch to glucose conversion yield of 94 and 92% when a wheat flour concentration and commercial starch concentration of 225 g L−1 was used, respectively. The use of crude broth filtrates resulted in the simultaneous hydrolysis of wheat protein and phytic acid, as was indicated by the increase in free amino nitrogen and phosphorus concentration, respectively. Biotechnol. Bioeng. 2007;97:61–72. © 2006 Wiley Periodicals, Inc.
Randomized clinical trial of postoperative hernia prophylaxis in open bariatric surgery
Authors: Strzelczyk J M , Szymański D , Nowicki M E , Wilczyński W , Gaszynski T , Czupryniak L
Published: September 2006

Background

Postoperative hernia following bariatric procedures is more common than in other groups of surgical patients, and remains a serious problem. Gastric bypass is the most often performed bariatric procedure and, despite the increasing popularity of a laparoscopic approach, many morbidly obese patients are still offered open procedures. The aim of this study was to assess the effects of prophylactic polypropylene mesh in morbidly obese patients undergoing gastric by-pass surgery.

Methods

The study randomized 74 patients undergoing open Roux-en-Y gastric bypass into two groups: wound closure with (n = 36) or without (n = 38) a polypropylene mesh. Mean(s.d.) body mass and body mass index in the mesh group were 137·3(24·5) kg and 46·2(7·1) kg/m2 and in the non-mesh group were 139·0(24·9) kg and 46·8(7·6) kg/m2 respectively. In the non-mesh group, the wound was closed with a polypropylene suture. Patients in the mesh group had in addition a polypropylene mesh inserted in a sublay manner.

Results

Patients were followed up for at least 6 (range 6–38) months. Hernia developed in eight patients in the non-mesh group but in none in the mesh group. The duration of hospital stay was similar in both groups: mean(s.d.) 8·4(3·2) and 10·3(5·9) days (P = 0·092). There were no serious complications in either group.

Conclusion

The use of a mesh prevented hernia development and did not lengthen hospital stay.
G Quadruplex‐Based FRET Probes with the Thrombin‐Binding Aptamer (TBA) Sequence Designed for the Efficient Fluorometric Detection of the Potassium Ion
Authors: Nagatoishi Satoru , Nojima Takahiko , Galezowska Elzbieta , Juskowiak Bernard , Takenaka Shigeori
Published: September 2006

The dual‐labeled oligonucleotide derivative, FAT‐0, carrying 6‐ carboxyfluorescein (FAM) and 6‐carboxytetramethylrhodamine (TAMRA) labels at the 5′ and 3′ termini of the thrombin‐binding aptamer (TBA) sequence 5′‐GGT TGG TGT GGT TGG‐3′, and its derivatives, FAT‐n (n=3, 5, and 7) with a spacer at the 5′‐end of a TBA sequence of TmA (m=2, 4, and 6) have been designed and synthesized. These fluorescent probes were developed for monitoring K+ concentrations in living organisms. Circular dichroism, UV‐visible absorption, and fluorescence studies revealed that all FAT‐n probes could form intramolecular tetraplex structures after binding K+. Fluorescence resonance energy transfer and quenching results are discussed taking into account dye–dye contact interactions. The relationship between the fluorescence behavior of the probes and the spacer length in FAT‐n was studied in detail and is discussed.
Self‐Assembled Small‐Molecule Microarrays for Protease Screening and Profiling
Authors: Urbina Hugo D. , Debaene François , Jost Bernard , Bole‐Feysot Christine , Mason Daniel E. , Kuzmic Petr , Harris Jennifer L. , Winssinger Nicolas
Published: September 2006

Small‐molecule microarrays are attractive for chemical biology as they permit the analysis of hundreds to thousands of interactions in a highly miniaturized format. Methods to prepare small‐molecule microarrays from combinatorial libraries by a self‐assembly process based on the sequence‐specific hybridization of peptide nucleic acid (PNA) encoded libraries to oligonucleotide arrays are presented. A systematic study of the dynamic range for multiple detection agents, including direct fluorescence of attached fluorescein and cyanine‐3 dyes, antibody‐mediated fluorescence amplification, and biotin–gold nanoparticle detection, demonstrated that individual PNA‐encoded probes can be detected to concentrations of 10 pM on the oligonucleotide microarrays. Furthermore, a new method for parallel processing of biological samples by using gel‐based separation of probes is presented. The methods presented in this report are exemplified through profiling two closely related cysteine proteases, cathepsin K and cathepsin F, across a 625‐member PNA‐encoded tetrapeptide acrylate library. A series of the specific cathepsin K and F inhibitors identified from the library were kinetically characterized and shown to correlate with the observed microarray profile, thus validating the described methods. Importantly, it was shown that this method could be used to obtain orthogonal inhibitors that displayed greater than tenfold selectivity for these closely related cathepsins.
Molecular characterization of the effects of Y‐27632
Authors: Darenfed Hassina , Dayanandan Bama , Zhang Tong , Hsieh Sidney H.‐K. , Fournier Alyson E. , Mandato Craig A.
Published: September 2006

Many key cellular functions, such as cell motility and cellular differentiation are mediated by Rho‐associated protein kinases (ROCKs). Numerous studies have been conducted to examine the ROCK signal transduction pathways involved in these motile and contractile events with the aid of pharmacological inhibitors such as Y‐27632. However the molecular mechanism of action of Y‐27632 has not been fully defined. To assess the relative contribution of these Rho effectors to the effects of Y‐27632, we compared the cytoskeletal phenotype, wound healing and neurite outgrowth in cells treated with Y‐27632 or subjected to knockdown with ROCK‐I, ROCK‐II or PRK‐2‐ specific siRNAs. Reduction of ROCK‐I enhances the formation of thin actin‐rich membrane extensions, a phenotype that closely resembles the effect of Y‐27632. Knockdown of ROCK II or PRK‐2, leads to the formation of disc‐like extenstions and thick actin bundles, respectively. The effect of ROCK‐I knockdown also mimicked the effect of Y‐27632 on wound closer rates. ROCK‐I knockdown and Y‐27632 enhanced wound closure rates, while ROCK‐II and PRK‐2 were not appreciably different from control cells. In neurite outgrowth assays, knockdown of ROCK‐I, ROCK‐II or PRK‐2 enhances neurite lengths, however no individual knockdown stimulated neurite outgrowth as robustly as Y‐27632. We conclude that several kinases contribute to the global effect of Y‐27632 on cellular responses. Cell Motil. Cytoskeleton 2006. © 2006 Wiley‐Liss, Inc.
How to determine free Gd and free ligand in solution of Gd chelates. A technical note
Authors: Barge Alessandro , Cravotto Giancarlo , Gianolio Eliana , Fedeli Franco
Published: September 2006

Gd(III) chelates are often used as reporting probes in magnetic resonance imaging applications. Their use relies on the assumption that their high stability ensures against the release of free ligand and free Gd3+ ions, which are both highly toxic to living systems. The presence of free Gd3+ ions may have a profound effect on the contrast in the MR image as they may form highly hydrated, macromolecular complexes endowed with very high relaxivity thus providing erroneous information on the extent of the contrast effect induced by the given reporting probe. Although the stability of a given complex may be high enough, the complexation step could not have been completed. Therefore any Gd complex preparation has to be carefully checked for the content of free ligand and free metal ions. Herein the currently used procedures that allow an assessment of the amounts of free metal ions and free ligand in a solution of a given Gd complex are described in detail. Copyright © 2006 John Wiley & Sons Ltd.
Topology awareness of overlay P2P networks
Authors: Rostami Habib , Habibi Jafar
Published: September 2006

In overlay networks, the mechanism of a peer randomly joining and leaving a network, causes a topology mismatch between the overlay and the underlying physical topology. This causes a large volume of redundant traffic in the underlying physical network as well as an extra delay in message delivery in the overlay network. Topology mismatch occurs because overlay networks are not aware of their underlying physical networks. In this paper we present a mathematical model for topology awareness of overlay networks (degree of matching between an overlay and its underlying physical network) and the efficiency of message delivery on them. Then we experimentally show that the model is precise in the real world. Also, after determining the computational complexity of the model, we propose an optimization heuristic algorithm to enhance efficiency of message exchange on overlay networks by increasing their topology awareness. Next, we present the results of running the algorithm on different kinds of random graph and show how we can implement the algorithm on peer‐to‐peer networks; we then simulate the implementation on some unstructured peer‐to‐peer overlay networks. Copyright © 2006 John Wiley & Sons, Ltd.
Management of real‐time streaming data Grid services
Authors: Fox Geoffrey , Aydin Galip , Bulut Hasan , Gadgil Harshawardhan , Pallickara Shrideep , Pierce Marlon , Wu Wenjun
Published: September 2006

We discuss our message‐based approach to managing real‐time data streams and building higher level services to produce and consume them. Our messaging system acts as a substrate that can be used to provide qualities of service to various streaming applications ranging from audio–video collaboration systems to sensor Grids. The messaging substrates are composed of distributed, hierarchically arranged message broker networks. Services such as filters are deployed along the edges of the network. We discuss the role of management systems for both broker networks and filter services: broker network topologies must be created and maintained, and distributed filters must be arranged in appropriate sequences. These managed broker networks may be applied to a wide range of problems. We discuss applications to audio–video collaboration in some detail and also describe applications to streaming Global Positioning System data streams. These provide specific application filters that can transform and republish message streams to the broker system. Copyright © 2006 John Wiley & Sons, Ltd.
Networking scientific resources in the Knowledge Grid environment
Authors: Zhuge Hai , Ding Lianhong , Li Xiang
Published: September 2006

Scientific documents, research instruments, researchers' abilities and co‐operation among researchers are fundamental resources of scientific research. This paper proposes an approach for effectively networking scientific resources by detecting community structures in self‐organized social network, discovering interest in information flow, capturing changes of interests over time and analyzing the relationship between peers. Copyright © 2006 John Wiley & Sons, Ltd.
Distribution of mobile agents in vulnerable networks
Authors: Qu Wenyu , Kitsuregawa Masaru , Shen Hong , Jin Yingwei
Published: September 2006

Advances in the Internet and the computer industry have created many new application areas for network routing such as Grid computing and also brings new challenges to traditional routing techniques. In this paper we propose a mobile agent‐based routing model in vulnerable networks for these applications. To characterize the behaviors of mobile agents and their effects on the network performance, we analyze the population distribution of mobile agents as a measurement of the computational resource consumption. Our analysis reveals theoretical insights into the statistical behaviors of mobile agents and provides useful tools for effectively managing mobile agents in large networks. Copyright © 2006 John Wiley & Sons, Ltd.
Autonomous semantic link networking model for the Knowledge Grid
Authors: Zhuge Hai
Published: September 2006

A semantic link network (SLN) consists of nodes (entities, features, concepts, schemas or communities) and semantic links between nodes. This paper proposes an autonomous SLN formalism to support intelligent applications on large‐scale networks. The formalism integrates the SLN logical reasoning with the SLN analogical reasoning and the SLN inductive reasoning, as well as existing techniques to form an autonomous semantic overly. The SLN logical reasoning mechanism derives implicit semantic relations by a semantic matrix and relevant addition and multiplication operations based on semantic link rules. The SLN analogical reasoning mechanism proposes conjectures on semantic relations based on structural mapping between nodes. The SLN inductive reasoning mechanism derives general semantics from special semantics. The cooperation of diverse reasoning mechanisms enhances the reasoning ability of each, therefore providing a powerful semantic ability for the semantic overlay. The self‐organizing diverse scales of the SLN support the intelligent applications of the Knowledge Grid. Copyright © 2006 John Wiley & Sons, Ltd.
Expanding the Diversity of Polycyclic Aromatics Through a Suzuki–Miyaura Cross‐Coupling Strategy
Authors: Kotha Sambasivarao , Lahiri Kakali
Published: September 2006

In recent years, Pd‐catalyzed Suzuki–Miyaura (SM) cross‐coupling reactions have revolutionized approaches to carbon–carbon bond formation. We have studied the application of SM coupling with several (ca. 16) complex molecular structures of particular relevance to scientists working at the interfaces of chemistry, biology, and materials sciences. In this regard, various structurally or biologically important polycyclic molecules (e.g., benzocrowns,C3‐symmetric molecules, 9,10‐disubstituted anthracenes, and sulfones) and unusual amino acid derivatives have been modified by this reaction, while it has also been shown that allylation of aromatics through the use of a commercially available boronic acid ester by SM coupling under CsF/Pd0conditions is feasible. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2006)
Development of Biotechnological Processes by Integrating Genetic and Engineering Methods
Authors: Hempel D. C.
Published: September 2006

The production systems and product lines used in the collaborative research centre (SFB 578) are considered to be an example for the superior goal to develop new tools, methods, data, and models for bioprocess design. Integrating genetic, biologic, biochemical and engineering methods for process design is helpful to reduce the development efforts and costs. Basic parameters describing the whole process have to be found and systems biotechnological models have to be developed. They should enable to synthesize products in biologically active form in high concentration, yield, and purity with as few production steps as possible.
New Approaches to Online Bioprocess Monitoring
Authors: Büttgenbach S. , Michalzik M. , Wilke R.
Published: September 2006

An overview on microfluidic components and microanalysis systems enabling online monitoring of bioprocesses is given in this paper. The design and performance of a capillary electrophoresis microchip and a quartz crystal microbalance, which can be used for measurements of target analytes from a continuous sample flow, are described.
Optimal linear and bilinear algorithms for power control in 3G wireless CDMA networks
Authors: Skataric Dobrila , Gajic Zoran , Qian Lijun
Published: September 2006

In this paper we present two power control algorithms that potentially can be used as efficient techniques for power updates in 3G wireless CDMA communication networks. The algorithms are obtained by optimising the signal‐to‐interference‐ratio (SIR) error. The control laws are distributed, respectively linear and bilinear, and either requires estimation of the channel interference (or the quantity inversely proportional to the signal interference, known as the channel variation) or the development of efficient numerical algorithms for solving a set of obtained algebraic equations. Simulation results show superiority of the proposed algorithm over the distributed constrained power control (DCPC) algorithm. Copyright © 2005 AEIT.
Pannexin1 is expressed by neurons and glia but does not form functional gap junctions
Authors: Huang Yan , Grinspan Judith B. , Abrams Charles K. , Scherer Steven S.
Published: September 2006

Pannexins are a newly described family of proteins that may form gap junctions. We made antisera against mouse pannexin1 (Panx1). HeLa cells expressing Panx1 have cell surface labeling, but not gap junction plaques, and do not transfer small fluorescent dyes or neurobiotin in a scrape‐loading assay. Neuro2a cells expressing Panx1 are not electrophysiologically coupled. Intracellular Panx1‐immunoreactivity, but not gap junction plaques, is seen in cultured oligodendrocytes, astrocytes, and hippocampal neurons. Thus, at least in these mammalian cells lines, Panx1 does not form morphological or functional gap junctions, and it remains to be demonstrated that Panx1 forms gap junction‐forming protein in the CNS. © 2006 Wiley‐Liss, Inc.
A sensitive and reliable semi‐quantitative real‐time PCR assay to detect JAK2 V617F in blood
Authors: Poodt J , Fijnheer R , Walsh IBB , Hermans MHA
Published: September 2006

Diagnosis of the myeloproliferative disorders, polycythemia vera (PV), essential thrombocythemia (ET) and idiopathic myelofibrosis (IMF) is difficult due to lack of diagnostic markers. Recently, the acquisition of a mutation in the Janus kinase 2 (JAK2) gene by hemopoietic cells has been described as a genetic defect underlying myeloproliferative disorders. The mutation leads to constitutive activation of JAK2, a tyrosine kinase involved in cytokine receptor signalling. Because of the clinical importance of this mutation (JAK2 V617F) in diagnosing myeloproliferative disorders and its relevance for disease progression, we developed a semi‐quantitative real‐time PCR test to detect JAK2 V617F. With this assay, quantities down to 0.8% JAK2 V617F amongst wild‐type DNA could reliably be detected. For quantification purposes, low intra‐ and inter‐assay variabilities ensure good reproducibility of the assay. Thus the JAK2 V617F qPCR assay described here is quick, robust, simple and more sensitive than direct sequencing, RFLP, ARMS assay and other methods published so far to detect JAK2 V617F. We therefore believe that the assay will contribute to early diagnosis of myeloproliferative disorders and to disease management, especially when JAK2‐specific inhibitors have become available for therapeutic use. Copyright © 2006 John Wiley & Sons, Ltd.