bluuebunny/crossref_metadata_2025 huggingface dataset:
Acquired Activated Protein C Resistance Associated with IgG Antibodies against β2-Glycoprotein I and Prothrombin as a Strong Risk Factor for Venous Thromboembolism
Authors: Nojima Junzo , Kuratsune Hirohiko , Suehisa Etsuji , Iwatani Yoshinori , Kanakura Yuzuru
Published: January 2005

Background: Venous thromboembolic events such as deep vein thrombosis and pulmonary embolism are common manifestations of antiphospholipid syndrome. Our aim was to clarify the roles of anti-phospholipid (aPL) antibodies in the pathogenesis of venous thromboembolism (VTE) in patients with systemic lupus erythematosus (SLE).

Methods and Results: We examined anti-cardiolipin/β2-glycoprotein I (anti-CL/β2-GPI) antibody concentrations, anti-phosphatidylserine/prothrombin (anti-PS/PT) antibody concentrations, and lupus anticoagulant (LA) activity in 87 patients with SLE (21 with VTE and 66 without thrombosis). Both anti-CL/β2-GPI and anti-PS/PT antibodies strongly correlated with LA activity. Multivariate logistic analysis confirmed that both anti-CL/β2-GPI and anti-PS/PT antibodies were significant independent risk factors for VTE (odds ratios = 4.98 and 7.54, respectively; 95% confidence intervals, 1.51–16.4 and 2.30–24.7, respectively). We therefore studied the in vitro effects of IgG fractions containing anti-CL/β2-GPI or anti-PS/PT antibodies on the anticoagulant activity of activated protein C (APC) and found that purified IgG containing anti-CL/β2-GPI or anti-PS/PT antibodies significantly hampered the anticoagulant activity of APC. We also studied the ability of IgG fractions to impede the anticoagulant activity of APC before and after complete removal of anti-CL/β2-GPI or anti-PS/PT antibodies by adsorption. Removal of anti-CL/β2-GPI or anti-PS/PT antibodies from all positive IgG samples clearly decreased the inhibitory effect of those samples on APC anticoagulant activity.

Conclusions: Anti-CL/β2-GPI and anti-PS/PT antibodies independently cause APC resistance, which may contribute to risk of VTE in patients with SLE.
Adaptive behavior in children with CHARGE syndrome
Authors: Salem‐Hartshorne Nancy , Jacob Susan
Published: January 2005

The “R” in the mnemonic “CHARGE” has historically stood for “Retardation of Growth and Development.” Early medical reports describing mental retardation in CHARGE syndrome have not used convincing means to assess this attribute. This article investigated the range of developmental ability in individuals with CHARGE as measured through an adaptive behavior scale, the Adaptive Behavior Evaluation Scale (ABES) [Carney (1995): The Adaptive Behavior Evaluation Scale home version technical manual‐revised. 126p.], over time. Parents of individuals with CHARGE syndrome were surveyed twice over a 4‐year time span (N = 100, 85) to obtain information about adaptive behavior and specific CHARGE characteristics. There was a significant decline in ABES scores over the 4‐year period. However, at Time two, one‐half of the children achieved a standard score above 70. Correlation and regression analyses at Time one and Time two revealed negative relationships between (a) age at walking, (b) degree of hearing impairment, (c) degree of visual impairment, and (d) medical involvement variables and the dependent variable, adaptive behavior. In both studies, age at walking was the best predictor of scores. Analysis of variance confirmed that medical involvement and degree of vision impairment were related to adaptive behavior scores because they were also related to age at walking. Age at walking and medical involvement at Time one were found to be significantly different between those who improved and declined in adaptive behavior scores over time. Adaptive behavior scores from both studies revealed a much broader and higher‐reaching range of ability for this population than has been previously reported in the literature. © 2005 Wiley‐Liss, Inc.
C‐reactive protein as a predictor of infliximab treatment outcome in patients with rheumatoid arthritis: Defining subtypes of nonresponse and subsequent response to etanercept
Authors: Buch Maya H. , Seto Yohei , Bingham Sarah J. , Bejarano Victoria , Bryer Domini , White Jo , Emery Paul
Published: January 2005

Objective

Nonresponse to anti–tumor necrosis factor α in patients with rheumatoid arthritis (RA) is poorly understood. The aims of this study were to define nonresponse patterns using infliximab and C‐reactive protein (CRP) profiles, to assess the predictive power of a CRP response for outcome, and to correlate these findings with subsequent response to etanercept.

Methods

We studied 207 patients with resistant RA who were started on treatment with infliximab. After 12 weeks, the American College of Rheumatology 20% improvement criteria (ACR20) were used to classify patients as responders (ACR20 response or greater) or nonresponders (NRs). The NRs were further subdivided into 3 groups according to the CRP response at weeks 2, 6, and 12. Within the NR group, those with a suppressed CRP at week 12 continued taking infliximab for a further 12 weeks; those without a CRP response were switched to etanercept, and the ACR response at 12 weeks was calculated.

Results

At week 12, 54% of patients achieved an ACR20 response, and 46% failed to achieve a response. Of the NRs, 63% demonstrated a significant reduction in the CRP level at week 12, 59% of whom achieved an ACR20 response at week 24 on continuation of infliximab. Of the patients who did not demonstrate a significant reduction in the CRP level after the first infusion, 86% failed to show a biochemical or ACR20 response by week 12. Twenty‐four percent of the NRs had a temporary reduction in the CRP level, and 13% of the NRs showed no CRP reduction. Seventy‐five percent of these NRs switched to etanercept, and 68% of this group achieved an ACR20 response at week 12 (51% achieved an ACR50 response), with a CRP response in 63%.

Conclusion

Infliximab NRs comprise subtypes with distinct CRP patterns. Failure to suppress the CRP at week 2 identified the majority of patients who were NRs at week 12. CRP suppression at week 12 in the NRs was associated with a late clinical improvement with infliximab treatment (24 weeks), whereas failure to suppress the CRP at week 12 was associated with a good response on switching to etanercept.
The HLA–B*5703 allele confers susceptibility to the development of spondylarthropathies in Zambian human immunodeficiency virus–infected patients with slow progression to acquired immunodeficiency syndrome
Authors: López‐Larrea C. , Njobvu P. D. , González S. , Blanco‐Gelaz M. A. , Martínez‐Borra J. , López‐Vázquez A.
Published: January 2005

Objective

To analyze the HLA distribution in a population of individuals from Zambia in order to establish a possible relationship between the progression of human immunodeficiency virus (HIV) infection and the development of spondylarthropathy (SpA).

Methods

A large epidemiologic analysis of rheumatology patients living in Zambia was performed in order to identify those who had SpA. We selected 64 patients with SpA and found that 54 also had HIV type 1 (HIV‐1) infection; only 10 were HIV negative. Additionally, we selected 57 HIV‐infected individuals without SpA and 43 healthy controls. Among all of the HIV‐1–infected patients, 25 SpA‐positive and 24 SpA‐negative patients were classified as slow progressors to acquired immunodeficiency syndrome (AIDS), and 8 SpA‐positive and 26 SpA‐negative patients were classified as rapid progressors. All patients were typed for HLA–B alleles.

Results

Of the 64 patients with SpA, HIV infection was observed in 54 (84%). The frequency of B*5703 was increased in patients who were SpA positive and HIV positive compared with patients who were SpA negative and HIV positive (P = 0.0002, odds ratio [OR] 8.28). Among patients who were slow progressors to AIDS, this allele was overrepresented in those with SpA compared with those without SpA (corrected P = 0.001, OR 26.25).

Conclusion

HLA–B*5703 seems to be a protective allele against the progression of HIV infection but could influence the increased incidence of SpA observed in this population.
Freshly isolated osteoarthritic chondrocytes are catabolically more active than normal chondrocytes, but less responsive to catabolic stimulation with interleukin‐1β
Authors: Fan Zhiyong , Bau Brigitte , Yang Huiqing , Soeder Stephan , Aigner Thomas
Published: January 2005

Objective

Interleukin‐1β (IL‐1β) is one potentially important cytokine during cartilage destruction. The aim of this study was to investigate whether there are different effects of low and high concentrations of IL‐1β on the expression level of anabolic genes (type II collagen, aggrecan), catabolic genes (matrix metalloproteinase 1 [MMP‐1], MMP‐2, MMP‐3, MMP‐13, and ADAMTS‐4), and cytokines (IL‐1β, IL‐6, and leukemia inhibitory factor [LIF]) by articular chondrocytes (normal and osteoarthritic). Determination of whether there was a difference in reactivity between normal and osteoarthritic chondrocytes was also a goal of this study.

Methods

Gene expression levels were detected by real‐time polymerase chain reaction from isolated (nonpassaged) chondrocytes (normal [n = 6]; osteoarthritic [n = 7]) after stimulation with 0.01 ng, 0.1 ng, 1 ng, and 10 ng/ml IL‐1β.

Results

In normal adult articular chondrocytes the expression of both aggrecan and type II collagen genes was significantly down‐regulated, whereas matrix‐degrading proteases (except MMP‐2), as well as the investigated cytokines, were induced by IL‐1β in a dose‐dependent manner. The strongest regulation was found for IL‐6 and LIF. Osteoarthritic chondrocytes showed strongly increased levels of catabolic enzymes and mediators, but were less responsive to further stimulation with IL‐1β.

Conclusion

Our study confirms that IL‐1β activity is critically dependent on both the applied concentration and the reactivity of the cells stimulated. The responsiveness appears to be significantly reduced in late‐stage osteoarthritic chondrocytes. However, these cells show high basic expression levels of catabolic enzymes and mediators. Thus, it remains open whether our data indicate that osteoarthritic chondrocytes are per se not responsive to IL‐1β or are already so strongly stimulated (e.g., by IL‐1) during the disease process that they are refractory to further stimulation.
Repair of articular cartilage defect by autologous transplantation of basic fibroblast growth factor gene–transduced chondrocytes with adeno‐associated virus vector
Authors: Yokoo Naoki , Saito Tomoyuki , Uesugi Masaaki , Kobayashi Naomi , Xin Ke‐Qin , Okuda Kenji , Mizukami Hiroaki , Ozawa Keiya , Koshino Tomihisa
Published: January 2005

Objective

To examine the effects of basic fibroblast growth factor (bFGF) gene–transduced chondrocytes on the repair of articular cartilage defects.

Methods

LacZ gene or bFGF gene was transduced into primary isolated rabbit chondrocytes with the use of a recombinant adeno‐associated virus (AAV) vector. These gene‐transduced chondrocytes were embedded in collagen gel and transplanted into a full‐thickness defect in the articular cartilage of the patellar groove of a rabbit. The efficiency of gene transduction was assessed according to the percentage of LacZ‐positive cells among the total number of living cells. The concentration of bFGF in the culture supernatant was measured by enzyme‐linked immunosorbent assay to confirm the production by bFGF gene–transduced chondrocytes. At 4, 8, and 12 weeks after transplantation, cartilage repair was evaluated histologically and graded semiquantitatively using a histologic scoring system ranging from 0 (complete regeneration) to 14 (no regeneration) points.

Results

LacZ gene expression by chondrocytes was maintained until 8 weeks in >85% of the in vitro population. LacZ‐positive cells were found at the transplant sites for at least 4 weeks after surgery. The mean concentration of bFGF was significantly increased in bFGF gene–transduced cells compared with control cells (P < 0.01). Semiquantitative histologic scoring indicated that the total score was significantly lower in the bFGF‐transduced group than in the control group throughout the observation period.

Conclusion

These results demonstrated that gene transfer to chondrocytes by an ex vivo method was established with the AAV vector, and transplantation of bFGF gene–transduced chondrocytes had a clear beneficial effect on the repair of rabbit articular cartilage defects.
Responses of lymphocytes of patients with rheumatoid arthritis to IgG modified by oxygen radicals or peroxynitrite
Authors: Grinnell Susan , Yoshida Koji , Jasin Hugo E.
Published: January 2005

Objective

We have previously demonstrated the presence of IgG aggregates modified by oxygen radicals (chlorinated IgG [Cl‐IgG]) and peroxynitrite (nitrated IgG [N‐IgG]) in synovial fluid of patients with rheumatoid arthritis (RA). A possible explanation for the longstanding chronic inflammatory process in RA is the establishment of an immune response to autoantigens. This study was undertaken to examine whether a T cell response to oxidatively modified IgG contributes to the inflammation in RA.

Methods

We studied in vitro lymphocyte proliferation and interleukin 2 (IL‐2) secretion in response to a common antigen (mumps), N‐IgG, Cl‐IgG, and heat‐aggregated IgG (H‐IgG) (control) in 15 normal blood donors and 16 RA patients not receiving immunosuppressive drugs.

Results

The responses of RA lymphocytes to mumps antigen were significantly lower that those in controls (mean ± SEM 2,577 ± 217 versus 6,367 ± 365 counts per minute/well; P < 0.02). However, whereas in normal donors the cell responses to N‐IgG and Cl‐IgG were not significantly different than responses to H‐IgG (N‐IgG/H‐IgG ratio 1.2 ± 0.2, Cl‐IgG/H‐IgG 1.5 ± 0.2), the RA lymphocyte responses to N‐IgG and Cl‐IgG were significantly higher than the responses to H‐IgG (N‐IgG/H‐IgG 7.4 ± 2.5, Cl‐IgG/H‐IgG 4.8 ± 1.2). When ratios in RA cells were compared with normal cell responses as a group, there was a significant difference for both N‐IgG (P < 0.017) and Cl‐IgG (P < 0.014). When selected normal and RA lymphocyte culture supernatants were assayed for IL‐2 secretion, the increase in IL‐2 never exceeded 2‐fold in normal cell cultures incubated with any of the IgG compared with unstimulated cultures, whereas responses of RA cells, particularly those incubated with N‐IgG, were increased (range 2.6–15.7‐fold) compared with unstimulated controls.

Conclusion

These results suggest that in RA there are circulating T cells that are responsive to oxidatively modified IgG, a possible pathogenic mechanism contributing to the chronic inflammatory process within the inflamed joint.
Intake of purine‐rich foods, protein, and dairy products and relationship to serum levels of uric acid: The Third National Health and Nutrition Examination Survey
Authors: Choi Hyon K. , Liu Simin , Curhan Gary
Published: January 2005

Objective

Various commonly consumed foods have long been suspected of affecting the serum uric acid level, but few data are available to support or refute this impression. Our objective was to evaluate the relationship between dietary factors and serum uric acid levels in a nationally representative sample of men and women in the US.

Methods

Using data from 14,809 participants (6,932 men and 7,877 women) ages 20 years and older in the Third National Health and Nutrition Examination Survey (for the years 1988–1994), we examined the relationship between the intake of purine‐rich foods, protein, and dairy products and serum levels of uric acid. Diet was assessed with a food‐frequency questionnaire. We used multivariate linear regression to adjust for age, sex, total energy intake, body mass index, use of diuretics, β‐blockers, allopurinol, and uricosuric agents, self‐reported hypertension and gout, serum creatinine level, and intake of alcohol.

Results

The serum uric acid level increased with increasing total meat or seafood intake and decreased with increasing dairy intake. After adjusting for age, the differences in uric acid levels between the extreme quintiles of intake were 0.48 mg/dl for total meat (95% confidence interval [95% CI] 0.34, 0.61; P < 0.001 for trend), 0.16 mg/dl for seafood (95% CI 0.06, 0.27; P = 0.005 for trend), and –0.21 mg/dl for total dairy intake (95% CI –0.37, –0.04; P = 0.02 for trend). After adjusting for other covariates, the differences between the extreme quintiles were attenuated but remained significant (P < 0.05 for all comparisons). The total protein intake was not associated with the serum uric acid level in multivariate analyses (P = 0.74 for trend). Those who consumed milk 1 or more times per day had a lower serum uric acid level than did those who did not drink milk (multivariate difference –0.25 [95% CI –0.40, –0.09]; P < 0.001 for trend). Similarly, those who consumed yogurt at least once every other day had a lower serum uric acid level than did those who did not consume yogurt (multivariate difference –0.26 [95% CI –0.41, –0.12]; P < 0.001 for trend).

Conclusion

These findings from a nationally representative sample of adults in the US suggest that higher levels of meat and seafood consumption are associated with higher serum levels of uric acid but that total protein intake is not. Dairy consumption was inversely associated with the serum uric acid level.
Successful treatment of psoriatic onycho‐pachydermo periostitis (POPP) with adalimumab
Authors: Bongartz T. , Härle P. , Friedrich S. , Karrer S. , Vogt T. , Seitz A. , Müller‐Ladner U.
Published: January 2005

Psoriatic onycho‐pachydermo periostitis (POPP) is recognized as a rare subset of psoriatic arthritis, characterized by psoriatic onychodystrophy, connective tissue thickening above the distal phalanx, and a periosteal reaction. Therapy for this rare disease is based on treatments used for psoriatic arthritis, but traditional disease‐modifying antirheumatic drugs, such as sulfasalazine and methotrexate, have shown inconsistent and unsatisfactory results. We report herein a successful therapeutic approach for POPP using the fully human anti–tumor necrosis factor (TNF) antibody adalimumab in a 42‐year‐old male patient. After 4 months of anti‐TNF treatment, a remarkable normalization of the clinical appearance was achieved and magnetic resonance imaging showed complete resolution of the initial inflammatory lesions. Therefore, we consider a TNF‐blocking strategy as promising for treatment of POPP.
Evidence that anti–tumor necrosis factor therapy with both etanercept and infliximab induces apoptosis in macrophages, but not lymphocytes, in rheumatoid arthritis joints: Extended report
Authors: Catrina Anca Irinel , Trollmo Christina , af Klint Erik , Engstrom Marianne , Lampa Jon , Hermansson Ylva , Klareskog Lars , Ulfgren Ann Kristin
Published: January 2005

Objective

Treatment of rheumatoid arthritis (RA) with tumor necrosis factor (TNF) antagonists is highly effective, but their mechanisms of action are not completely clear. Since anti‐TNF therapy induces a decrease in synovial cellularity, this study focused on the modulation of RA synovial apoptosis following treatment with either soluble TNF receptor (etanercept) or TNF chimeric monoclonal antibody (infliximab).

Methods

Apoptosis (TUNEL and active caspase 3 staining) and cell surface markers were evaluated by immunohistochemistry in synovial biopsy samples obtained before and after 8 weeks of treatment with etanercept (12 patients) or infliximab (9 patients). We also determined by flow cytometry the in vitro effect of etanercept and infliximab on apoptosis of RA mononuclear cells derived from the synovial fluid (SF) and peripheral blood (PB).

Results

Eight weeks of treatment with etanercept and with infliximab significantly increased synovial apoptosis. This change was accompanied by a significant decrease in the synovial monocyte/macrophage population. The decrease in lymphocyte numbers did not reach statistical significance. In vitro, 24 hours of incubation with either etanercept or infliximab induced apoptosis of the SF monocyte/macrophage population. PB monocyte/macrophages were less susceptible to anti‐TNF–mediated apoptosis. No changes in the rate of apoptosis were observed in the lymphocyte population derived from either SF or PB.

Conclusion

In RA patients, both etanercept and infliximab are able to induce cell type–specific apoptosis in the monocyte/macrophage population. This suggests a potential pathway that would account for the diminished synovial inflammation and the decreased numbers of synovial macrophages evident after TNF blockade.
Increased CD4+ T cell infiltrates in rheumatoid arthritis–associated interstitial pneumonitis compared with idiopathic interstitial pneumonitis
Authors: Turesson Carl , Matteson Eric L. , Colby Thomas V. , Vuk‐Pavlovic Zvezdana , Vassallo Robert , Weyand Cornelia M. , Tazelaar Henry D. , Limper Andrew H.
Published: January 2005

Objective

To study lymphocyte markers in rheumatoid arthritis (RA)–associated interstitial pneumonitis (IP) compared with idiopathic IP.

Methods

Paraffin‐embedded lung biopsy specimens from patients with RA (n = 15) and from those without RA (n = 16), all of whom had a diagnosis of either nonspecific IP or usual IP, were studied. Tissue sections from each patient were reviewed by a pathologist, who was blinded to the clinical data. Age and pulmonary function test results were similar in RA and non‐RA patients. After high‐temperature antigen unmasking, sections were incubated with mouse monoclonal antibodies directed against CD3, CD4, CD8, CD16, and CD20. All slides were coded, and digital images (100× magnification) of the entire tissue area were obtained. Staining was quantified using computer‐assisted image analysis.

Results

Staining for CD4 was more prominent in patients with RA than in the non‐RA comparison group (median 9.3 cells/mm2, interquartile range [IQR] 5.5–27.3 versus 0.6 cells/mm2, IQR 0.2–1.9;P= 0.002). CD4+ cell counts were increased in RA patients with nonspecific IP as well as in RA patients with usual IP, with no major difference between these groups. Results were similar for quantification of CD3 (P= 0.012). There was a less striking trend toward more CD8+ cells in RA patients (P= 0.27 versus those with non‐RA lung disease).

Conclusion

IP lesions in patients with RA are characterized by an increased number of CD4+ cells, as compared with that in patients with idiopathic IP. This finding suggests that CD4+ T cells are critical for the development of pulmonary manifestations in RA, and may have implications for the treatment of RA‐associated lung disease.
Association of a functional single‐nucleotide polymorphism of PTPN22, encoding lymphoid protein phosphatase, with rheumatoid arthritis and systemic lupus erythematosus
Authors: Orozco Gisela , Sánchez Elena , González‐Gay Miguel A. , López‐Nevot Miguel A. , Torres Belén , Cáliz Rafael , Ortego‐Centeno Norberto , Jiménez‐Alonso Juan , Pascual‐Salcedo Dora , Balsa Alejandro , de Pablo Rosario , Nuñez‐Roldan Antonio , González‐Escribano Ma Francisca , Martín Javier
Published: January 2005

Objective

To assess the possible association between the PTPN22 gene 1858C→T polymorphism and the predisposition and clinical expression of 2 systemic autoimmune diseases, rheumatoid arthritis (RA) and systemic lupus erythematosus (SLE).

Methods

Our study population consisted of 826 RA patients, 338 SLE patients, and 1,036 healthy subjects. All subjects were of Spanish Caucasian origin. Genotyping of the PTPN22 gene 1858C→T polymorphism was performed by real‐time polymerase chain reaction technology, using the TaqMan 5′‐allele discrimination assay.

Results

The overall distribution of genotypes in the RA patients was significantly different from that in the controls (P = 0.005, by chi‐square test with 2 × 3 contingency tables). We observed a statistically significant difference in the distribution of the PTPN22 1858T allele between healthy subjects (7.4%), and RA patients (10.4%) (P = 0.001, odds ratio [OR] 1.45 [95% confidence interval (95% CI) 1.15–1.83]). In addition, PTPN22 1858 C/T and T/T genotypes were present at a significantly higher frequency in SLE patients than in controls (P = 0.02, OR 1.55 [95% CI 1.05–2.29]). Differences were also observed when allele frequencies were compared, with the PTPN22 1858T allele being present at a higher frequency among SLE patients (P = 0.03, OR 1.45 [95% CI 1.01–2.09]).

Conclusion

These results suggest that the PTPN22 1858T allele may confer differential susceptibility to RA and SLE in the Spanish population.
Association of SLC11A1 (NRAMP1) with persistent oligoarticular and polyarticular rheumatoid factor–negative juvenile idiopathic arthritis in Finnish patients: Haplotype analysis in Finnish families
Authors: Runstadler Jonathan A. , Säilä Hanna , Savolainen Anneli , Leirisalo‐Repo Marjatta , Aho Kimmo , Tuomilehto‐Wolf Eva , Tuomilehto Jaakko , Seldin Michael F.
Published: January 2005

Objective

The SLC11A1 (formerly called NRAMP1) gene is important in natural resistance to a variety of intracellular infections mediated by macrophages and has been proposed as a candidate gene for autoimmune disease susceptibility. The aim of this study was to examine susceptibility in Finnish patients with persistent oligoarticular and polyarticular rheumatoid factor (RF)–negative juvenile idiopathic arthritis (JIA) due to the presence of the SLC11A1 locus on chromosome 2.

Methods

A total of 234 Finnish JIA nuclear families and 639 elderly Finnish controls without a history of JIA were evaluated for association with JIA at 3 intragenic single‐nucleotide polymorphisms: an intragenic insertion/deletion, a promoter microsatellite (NRAMP1), and a 3′ microsatellite (D2S1471).

Results

Analysis of marker haplotypes demonstrated a strong association of Finnish JIA with 6‐marker, 4‐marker, and 2‐marker haplotypes. Most impressively, 1 of the 6‐marker haplotypes showed an odds ratio (OR) of 4.0 (95% confidence interval [95% CI] 2.6–6.2) in all JIA patients, 3.5 (95% CI 1.9–6.5) in those with persistent oligoarticular JIA, and 4.1 (95% CI 2.5–6.7) in those with polyarticular RF‐negative JIA. Stratification of the haplotype data suggested that susceptibility to JIA in the haplotype spanning the SLC11A1 locus is independent (P < 0.01) of an association with a DRB1 JIA shared epitope (DRB1*JIASE) that includes well‐characterized strong susceptibility to DRB1*08 and *11 alleles. This SLC11A1 haplotype also had an additive effect with DRB1*JIASE in those with polyarticular, but not those with persistent oligoarticular, disease (P = 0.06, OR 2.9 [95% CI 0.9–9.2] versus P = 0.5, OR 1.6 [95% CI 0.4–6.0]).

Conclusion

Taken together, these data provide support for the existence of a locus at or near SLC11A1 that is a strong susceptibility factor for JIA in Finnish patients.
Antibodies against cyclic citrullinated peptide are associated with HLA–DR4 in simplex and multiplex polyarticular‐onset juvenile rheumatoid arthritis
Authors: Ferucci Elizabeth D. , Majka Darcy S. , Parrish Lezlie A. , Moroldo Marta B. , Ryan Mary , Passo Murray , Thompson Susan D. , Deane Kevin D. , Rewers Marian , Arend William P. , Glass David N. , Norris Jill M. , Holers V. Michael
Published: January 2005

Objective

Anti–cyclic citrullinated peptide (anti‐CCP) antibodies have been detected in patients with juvenile rheumatoid arthritis (JRA), particularly in those with polyarticular, rheumatoid factor (RF)‐positive JRA. Our objectives were to determine whether anti‐CCP antibodies are associated with HLA–DR4 in children with polyarticular JRA, whether anti‐CCP antibodies are associated with clinical features of disease, and whether affected sibling pairs (ASPs) with JRA are concordant for this antibody.

Methods

Stored serum samples obtained from 230 HLA‐typed patients with JRA (77 with polyarticular‐onset disease and 153 with pauciarticular‐ or systemic‐onset disease), 100 JRA ASPs, and 688 healthy children were tested for anti‐CCP antibodies and RF.

Results

Thirteen percent of the patients with polyarticular‐onset JRA and 2% of the other JRA patients exhibited anti‐CCP antibodies, compared with only 0.6% of the controls. Fifty‐seven percent of RF‐positive patients with polyarticular‐onset JRA had anti‐CCP antibodies. HLA–DR4–positive patients with polyarticular‐onset JRA were more likely to have anti‐CCP antibodies than were those without HLA–DR4 alleles (odds ratio [OR] 5.20, 95% confidence interval [95% CI] 1.30–20.9). Anti‐CCP antibodies were associated with polyarticular onset (OR 7.46, 95% CI 1.99–28.0), a polyarticular disease course (OR 9.78, 95% CI 1.25–76.7), and erosive disease (OR 14.3, 95% CI 3.01–67.9). Concordance rates for anti‐CCP antibodies among ASPs were statistically significant.

Conclusion

These data demonstrate increased anti‐CCP antibody formation in HLA–DR4–positive patients with polyarticular‐onset JRA. The overall prevalence of anti‐CCP antibodies in JRA is low, but a substantial proportion of RF‐positive patients with polyarticular‐onset JRA have these antibodies. Anti‐CCP antibodies in JRA are associated with polyarticular onset, a polyarticular course, and erosive disease.
Presentation and analysis of data on radiographic outcome in clinical trials: Experience from the TEMPO study
Authors: Heijde Désirée van der , Landewé Robert , Klareskog Lars , Rodríguez‐Valverde Vicente , Settas Lucas , Pedersen Ronald , Fatenejad Saeed
Published: January 2005

Objective

To evaluate different methods of presentation and analysis of radiographic data in a rheumatoid arthritis (RA) randomized controlled trial.

Methods

A double‐blind randomized controlled trial including 682 patients with active RA who were treated with methotrexate, etanercept, or a combination of the 2 drugs was used for this study. Probability plots of the change from baseline to year 1 were produced to visualize progression, and were compared with usual descriptive statistics. The primary analysis of the trial (based on annualized actual mean change from baseline in total Sharp score at 1 year, using linear imputation) was challenged using various ways of handling missing information with alternative imputation methods, and by various statistical analyses including analysis of covariance (ANCOVA) and mixed model analysis on both raw and log‐transformed data.

Results

Probability plots provided detailed insight into the differentiated treatment effects between the 3 arms of this study. As adjuncts to formal hypothesis testing, these plots were more useful for presenting data than were summary descriptive statistics or use of preset cutoff points to define lack of progression. Additional analyses presented here support the results obtained with the per‐protocol analysis that showed an advantage of the combination treatment compared with the monotherapy arms and for etanercept versus methotrexate alone. Various ways of handling missing information confirmed the robustness of the results. In addition, both ANCOVA and mixed model analyses on raw and on log‐transformed data produced similar results.

Conclusion

We suggest a panel of alternative analysis methods and alternative ways of handling missing information to verify that the radiographic results reported in an randomized controlled trial are not influenced by technical factors, such as interpolation, handling of missing data, and choice of statistical tests.
The non–major histocompatibility complex quantitative trait locus Cia10 contains a major arthritis gene and regulates disease severity, pannus formation, and joint damage
Authors: Brenner Max , Meng Hsiang‐Chi , Yarlett Nuriza C. , Griffiths Marie M. , Remmers Elaine F. , Wilder Ronald L. , Gulko Pércio S.
Published: January 2005

Objective

To construct rats congenic for the chromosome 2 arthritis‐regulatory quantitative trait locus Cia10, originally identified in a (DA × ACI)F2 intercross rat strain that had been assessed for collagen‐induced arthritis (CIA), and to determine the effect of this congenic interval on arthritis severity, joint histologic structure, and cytokine transcription in rats with pristane‐induced arthritis (PIA).

Methods

A 52.6‐MB interval derived from the ACI (CIA‐ and PIA‐resistant) strain and containing the Cia10 interval was introgressed into the DA (arthritis‐susceptible) background through genotype‐guided congenic breeding. Homozygous male and female DA.ACI(Cia10) congenic rats were studied for their susceptibility to and severity of PIA, and were compared with same‐sex DA rats. Histologic analyses were done on hind paws collected on day 32 following the pristane injection. Levels of interleukin‐1β (IL‐1β) and tumor necrosis factor α (TNFα) messenger RNA (mRNA) were measured with real‐time polymerase chain reaction on synovial tissues from day‐32 ankles.

Results

Both male and female DA.ACI(Cia10) congenic rats developed a significantly milder form of arthritis, with a 95% and 92% reduction in the arthritis severity index compared with DA male and female controls, respectively (males P ≤ 0.001 and females P = 0.003). DA.ACI(Cia10) congenic rat synovial tissue was more likely to preserve its normal histologic architecture, including minimal to no cartilage and bone erosions, synovial hyperplasia, and pannus formation, and reduced numbers of vessels (angiogenesis), when compared with DA synovial tissue. There was a 2.7‐ and 2.4‐fold reduction in the amount of IL‐1β and TNFα mRNA, respectively, in the synovial tissue of DA.ACI(Cia10) congenic rats compared with DA rats. Sequencing analyses of complementary DNA for the Cia10‐predicted candidate gene Ptpn8, the rat homolog of the rheumatoid arthritis (RA)–susceptibility gene PTPN22, revealed no polymorphisms between the DA and ACI strains.

Conclusion

This study determined that Cia10 harbors a major autoimmune arthritis–regulatory gene. This gene regulates clinical disease severity, histologic damage, and the levels of at least two central proinflammatory cytokines. We are in the process of narrowing down the critical region for positional cloning of the Cia10 gene. The identification of this gene will provide novel targets or pathways for focused candidate‐gene studies in RA.
Small interfering RNA inhibition of SPARC attenuates the profibrotic effect of transforming growth factor β1 in cultured normal human fibroblasts
Authors: Zhou Xiaodong , Tan Filemon K. , Guo Xinjian , Wallis Debra , Milewicz Dianna M. , Xue Sarah , Arnett Frank C.
Published: January 2005

Objective

SPARC (secreted protein, acidic and rich in cysteine), or osteonectin, is a matricellular protein. Recently, it was observed to be overexpressed in fibroblasts obtained from the skin of patients with scleroderma, as well as in different tissues from patients with several other fibrotic disorders. Moreover, a genetic polymorphism in SPARC has been associated with susceptibility to scleroderma. Transforming growth factor β1 (TGFβ1) is a profibrotic cytokine that stimulates excessive collagen production in patients with scleroderma or other fibrotic diseases. The purpose of this study was to examine whether specific inhibition of SPARC can influence the expression of type I collagen and ameliorate the profibrotic activity of TGFβ1 on normal human fibroblasts.

Methods

Fibroblasts obtained from the skin of 4 healthy individuals were cultured and transfected with SPARC small interfering RNA (siRNA). TGFβ was used as a fibrosis stimulus in cultured fibroblasts. Real‐time quantitative reverse transcriptase–polymerase chain reaction and Western blotting were used to measure transcription and protein levels of SPARC and type I collagen, respectively.

Results

The fibroblasts transfected with SPARC siRNA showed decreased expression of both SPARC and type I collagen. Exogenous TGFβ1 induced increased expression of both SPARC and type I collagen in cultured normal human fibroblasts, but this response was significantly blunted in the fibroblasts transfected with SPARC siRNA.

Conclusion

TGFβ1 can induce increased expression of both SPARC and type I collagen. Specific inhibition of SPARC led to decreased expression of type I collagen and attenuated the profibrotic effect of TGFβ1 in cultured normal human fibroblasts. Use of siRNA to silence SPARC represents a potential therapeutic approach to fibrotic disorders such as scleroderma.
Imaging Activation of Two Ras Isoforms Simultaneously in a Single Cell
Authors: Peyker Anna , Rocks Oliver , Bastiaens Philippe I. H.
Published: January 2005

Fluorescence resonance energy transfer (FRET) microscopy approaches have been used to study protein interactions in living cells. Up to now, due to the spectral requirements for FRET detection, this has been limited to the measurement of single protein interactions. Here we present a novel time‐resolved fluorescence imaging method for simultaneously monitoring the activation state of two proteins in a single cell. A Ras sensor, consisting of fluorescently labelled Ras and a fluorescently labelled Ras binding domain (RBD) of Raf, which reads out Ras activation by its interaction with RBD as a FRET signal, has been adapted for this purpose. By using yellow (YFP) and cyan (CFP) versions of the green fluorescent protein from Aquorea victoria as donors and a tandem construct of Heteractis crispa Red (tHcRed) as acceptor for both donors, two independent FRET signals can be measured at the same time. Measuring the YFP and CFP donor lifetimes by fluorescence‐lifetime imaging microscopy (FLIM) allows us to distinguish the two different FRET signals in a single cell. Using this approach, we show that different Ras isoforms and mutants that localize to the plasma membrane, to the Golgi or to both compartments display distinct activation profiles upon growth‐factor stimulation; this indicates that there is a differential regulation in cellular compartments. The method presented here is especially useful when studying spatiotemporal aspects of protein regulation as part of larger cellular signalling networks.
Evaluation of π‐acid chiral stationary phases deriving from tyrosine and related amino acids for the chromatographic resolution of racemates: Specific requirements for enantiorecognition ability
Authors: Liene M. , Macaudìre P. , Caude M. , Rosset R. , Tambut´ A.
Published: January 2005

Chromatographic applications of three novel chiral stationary phases (CSPs) deriving from (S)‐(N)‐(3,5‐dinitrobenzoyl)tyrosine are reported, under liquid chromatographic (LC) and subscritical fluid chromatographic (SubFC) conditions. Two grafting modes of the chiral moiety have been experimented starting either from γ‐mercaptopropyl‐silanized (type 1) or γ‐aminopropyl‐silanized (type 2) silica gels. For type 2 CSPs an evaluation of the stability of the amide linkage was achieved by means of SubFC; the relative contriution of ionic and covalent bindings to the ciral recognitio aility was then outlined. The chromatographic properties of these CSPs were compared with those of the corresponding CSPs deriving from phenylglycine, p‐hydroxyphenylglycine, and phenylalanine for the resolution of some tertiary phosphine oxide, naphthoyl amide, and α‐methylene γ‐lactam enantiomers. Some simple requirements regarding the solute and CSP structures for chiral recognition ability can be inferred from these results. In addition, the resolutio of π‐acid α‐N‐(3,5‐dinitrobenzoyl)amino esters was investigated on these π‐acid CSPs. An example of preparative scale chromatography is also presented.
Enantioselective inclusion complexation of 2,3,4,6‐tetra‐O‐acetyl‐D‐glycopyranose as a chiral host with (+)‐(r)‐phenylethylamine: x‐ray characterization of the complex
Authors: Francotte Eric , Rihs Greta
Published: January 2005

X‐ray analysis of the crystalline product obtained by reaction of 2,3,4,6‐Tetra‐O‐acetyl‐D‐glycopyranose with phenylethylamine revealed the formation of a real one‐to‐one inclusion complex. This complexaion is highly stereoselective, because only the (+)‐R‐enantiomeric form of the amine is included. Analogies to the mode of complexation of cellulose triaceate with chiral molecules in „inclusion chromatography”︁ are discussed.
Investigation on the enantiomeric impurity of epinephrine hydrochloride injections
Authors: Zhong‐Yuan Yang , Ru‐Zheng Xu
Published: January 2005

Epinephrine enantiomers were derived into diastereoisomers with the chiral reagent 2,3,4,6‐tetra‐O‐acetyl‐β‐D‐glucopyranosylisothiocyanate. The resolutions was carried out on a C18 column. The RS between (−)‐R‐ and (+)‐S‐isomers was 2.3. The retention time could be changed by adding a proper amount of acetonirile into the mobile phase. The results showed that (+)‐S‐isomer in the epinephrine hydrochloride injections increased during the period of storage.
Cytochrome P‐450‐catalyzed asymmetric epoxidation of simple prochiral and chiral aliphatic alkenes: species dependence and effect of enzyme induction on enantioselective oxirane formation
Authors: Wistuba D. , Nowotny H.‐P. , Träger O. , Schurig V.
Published: January 2005

The enantioselectivity of the in vitro conversion of simple prochiral and chiral aliphatic alkenes into oxiranes by liver microsomes of untreated or induced (phenobarbital) rats, of untreated or induced (phenobarbital, benzo[α] pyrene) mice, and of humans was determined by complexation gas chromatography. The enantiomeric excess (ee) of the epoxides extends from 0 (trimethyloxirane) to 50% (ethyloxirane). The configuration (R or S) of the enantiomers formed in excess is consistent for homologous oxiranes but is species dependent and in some cases influenced by enzyme induction. Enantioselectivity differences of aliphatic alkene epoxidation by human liver microsomes of four individuals are negligible.
Optical enrichment of dansyl‐rac‐amino acids by formation of crystalline inclusion complexes with cyclodextrins
Authors: Jin Heng L. , Stalcup Apryll , Armstrong Daniel W.
Published: January 2005

Optical enrichment from racemic dansyl‐leucine, dansyl‐norleucine, and dansyl‐phenylalanine with both β‐ and γ‐cyclodextrins in water is reported. Initial crystallization yielded the dansyl‐L‐leucine isomer complexed in excess with β‐cyclodextrin with an optical purity of 62–78% depending on experimental conditions. The optical purities obtained for L‐norleucine and L‐phenylalanine were 71 and 64%, respectively. The optical purity can be increased with continued recrystallization. The dansyl‐D‐leucine isomer was obtained in the mother liquor with an optical purity of 54–93% depending on experimental conditions. The optical purities obtained for D‐norleucine and D‐phenylalanine were 72 and 58%. The optical purity of the isomer depended on the molar ratio of host:guest and the pH value of the solution. Optimum enrichment of both enantiomers was achieved with host:guest ratios of 2 : 1 and 3 : 1. Although maximum crystalline yield of the dansyl‐leucine/CD inclusion complex was obtained at a pH of 3.5, optical purity of both enantiomers was less than that obtained at other pHs. The influence of the molar ratio of host:guest and the pH value of the solution are discussed. This method is suitable for large‐scale enantiomeric separations.
A vivid model of chiral recognition
Authors: Meyer Veronika R. , Rais Maya
Published: January 2005

Hands can be used to demonstrate the three‐point model of chiral recognition. The points of attachment are thumb, forefinger, and middle finger. This vivid model has the advantages of simplicity, perspicuity, and availability at any time, although two persons are necessary. It can be shown that two interactions are not sufficient for chiral recognition but that three attractive or two attractive and one repulsive attraction are needed. It can also be used to explain some possibilities of weakening or elusion of the three‐point model.
Stereoselectivity at muscarinic receptor subtypes: observations with the enantiomers of phenglutarimide
Authors: Lambrecht Günter , Feifel Roland , Mutschler Ernst
Published: January 2005

The affinity of the enantiomers of phenglutarimide at three muscarinic receptor subtypes was examined in vitro using field‐stimulated rabbit vas deferens (M1 receptors) and guinea pig atria (M2α receptors) and ileum (M2β receptors). Extremely high stereoselectivity was observed and higher affinities (up to 6000‐fold) were found for the (+)‐S‐enantiomer. The stereoselectivity ratios were different at the three subtypes, and the stereochemical demands made by the muscarinic receptors were most stringent at M1 receptors. (+)‐(S)‐Phenglutarimide was found to be a potent M1‐selective antagonist (pA2 at M1 = 8.53). Its receptor selectivity profile is qualitatively similar to that of pirenzepine. (−)‐(R)‐Phenglutarimide showed no comparable discriminatory properties.
The development of concepts of chiral discrimination
Authors: Mason Stephen F.
Published: January 2005

Pasteur's conjecture (1860) that biomolecular homochirality arose from a chiral natural force as yet inaccessible in the laboratory was supplanted by Fischer's (1894) “key and lock” hypothesis of stereoselection in enantiomer to diastereomer conversions, whether in the laboratory or in living organisms. Elaborations of the “key and lock” hypothesis by Haldane (1930) and Pauling (1948) have been illustrated and supported with modification by X‐ray diffraction crystal structures of enzyme–substrate complexes over the past quarter century.

Two types of mechanism for the product diastereoselectivity in the reactions of an enantiomer with an achiral reagent, early proposed, have recent support: one proposes a quasidiastereomeric structure for the enantiomer attacked in the ground state, the other for the corresponding transition state of the reaction. Approaches to the differential biological activity of two enantiomers postulate either the complete binding of each isomer to a chiral receptor site, resulting in diastereomeric complexes with inequivalent bioactivities, or the differential binding of the two isomers to a set of three sites, with which only one isomer is sterically congruent.

Biochemical homochirality, based on the chiral stereoselectivity of both biosynthetic and metabolic reactions, derives from the evolutionary pressure for a progressive enhancement of the kinetic efficiency and economy of those reactions. Recently Pasteur has been vindicated in part, and the problem of the original prebiotic enantiomeric excess left outstanding by Fischer has been solved. The unification of the electromagnetic with the weak interaction provided a universal chiral natural force, the electroweak interaction, which favours the chiral series selected during the course of biochemical evolution, both the D‐sugars and the L‐amino acids.
Species differences in the chirality of the carbonyl reduction of [14C] fenofibrate in laboratory animals and humans
Authors: Weil Andre , Caldwell John , Guichard Jean‐Pierre , Picot Gerard
Published: January 2005

The prochiral carbonyl group of fenofibrate (isopropyl 2‐[4‐(4‐chlorobenzoyl)phenoxy]‐2‐methyl propionate) is reduced during its metabolism giving rise to a chiral secondary alcohol, “reduced fenofibric acid.” Chiral and diastereomeric HPLC methods have been developed for the determination of its enantiomeric composition and these have been applied to the measurement of the “reduced fenofibric acid” enantiomers in urine of rats, guinea pigs, dogs, and human volunteers given [14C]fenofibrate. In the three animal species, the reduction is markedly enantioselective for the (–)‐isomer, the enantiomeric ratios (–/ +) being 95:5. This was not due to differences in the excretion of the enantiomers, since when racemic “reduced fenofibric acid” was given to rats it was recovered in the urine with the same enantiomeric composition as the dose form. In humans the ratio was 52:48 showing the lack of stereoselectivity of reduction in this species.