Rheumatoid Arthritis: Chen C

Yao Q, Li M, Yang H, Chai H, Fisher W, Chen C. · Molecular Surgeon Research Center, Michael E. DeBakey Department of Surgery, Baylor College of Medicine, Houston, Texas 77030, USA. · World J Surg. · Pubmed #15706440 No free full text.

Abstract: Cyclophilins are originally identified as cellular binding proteins for the immunosuppressive drug cyclosporin A. Many cyclophilins, including CypA, CypB, CypC, CypD, and Cyp40, have been discovered and shown to be ubiquitously distributed in many types of cells and organ systems. Recent investigations have uncovered many important properties and functions for cyclophilins including peptidyle-prolyl-isomerase activity and protein folding/repair; maintaining mitochondrial functions and involvement in apoptosis; roles in regulation of T-cell function and inflammation; interaction with CD147; and pathogenesis of vascular disease, human immunodeficiency virus infection, and rheumatoid arthritis. Furthermore, the expression and functions of cyclophilins may be correlated with tumor biology of several types of cancers including pancreatic carcinoma. Molecular mechanisms of cyclophilin-mediated biologic events and future directions of research are discussed in this review. Understanding the roles of cyclophilins in cancers and other organ systems will be crucial in determining clinical applications for the treatment or diagnosis of human diseases.

Sukel MP, van der Linden MW, Chen C, Erkens JA, Herings RM. · PHARMO Institute for Drug Outcome Research, Utrecht, The Netherlands. · Pharmacoepidemiol Drug Saf. · Pubmed #17963198 No free full text.

Abstract: PURPOSE: To compare treatment changes after the rofecoxib withdrawal with changes occurring normally and to re-assess 12 months afterwards. METHODS: The PHARMO database comprised medication and hospital discharge records of over 3 million inhabitants in the Netherlands. The Study cohort included chronic coxib users with a coxib prescription on 30th September 2004; the Reference cohort others with a coxib prescription on 1st June 2004. Initial treatment changes were based on first new prescription since cohort entry. Twelve-month changes were studied within the Study cohort only. RESULTS: The Study cohort (n = 6974) and Reference cohort (n = 5393) had similar demographics, stratified on type of coxib. In the Study cohort, 3341 (48%) initially stopped coxibs, of whom 1121 (16%) stopped all analgesic, versus 13 and 5% in the Reference cohort (p < 0.001). Among 'other coxib' users 32% stopped coxibs, and 15% stopped all analgesics, versus 14% and 4%, p < 0.001 in the Reference cohort. Among those who stopped coxibs, 34% switched to non-selective non-steroidal anti-inflammatory drug (nsNSAID) without PPI, 21% to nsNSAID with PPI, and 45% stopped NSAID treatment (Reference cohort: 35, 20, and 44%, respectively). These rates for 'other coxib users' were: switching to nsNSAID without PPI 23% (Study Cohort) versus 35% (Reference Cohort), 13 versus 28%, and 64 versus 37% respectively (p < 0.001). Twelve months later, stopping NSAID increased to 43%, stopping all analgesics to 32%. Rheumatologists continued coxibs more frequently than other caregivers (87, 65, 54%, respectively). CONCLUSIONS: The rofecoxib withdrawal resulted in a large proportion of patients who discontinued analgesic treatment altogether regardless of original coxib therapy.

Gottenberg JE, Loiseau P, Azarian M, Chen C, Cagnard N, Hachulla E, Puechal X, Sibilia J, Charron D, Mariette X, Miceli-Richard C. · Rhumatologie, Institut Pour la Santé et la Recherche Médicale U802, Université Paris-Sud 11, Hôpital Bicêtre, 78 rue du Général Leclerc, Assistance Publique-Hôpitaux de Paris, 94275 Le Kremlin Bicêtre, France. · Arthritis Res Ther. · Pubmed #17341301 links to  free full text

Abstract: CTLA-4 encodes cytotoxic T lymphocyte-associated antigen-4, a cell-surface molecule providing a negative signal for T-cell activation. CTLA-4 gene polymorphisms have been widely studied in connection with genetic susceptibility to various autoimmune diseases, but studies have led to contradictory results in different populations. This case-control study sought to investigate whether CTLA-4 CT60 and/or +49A/G polymorphisms were involved in the genetic predisposition to primary Sjögren syndrome (pSS). We analysed CTLA-4 CT60 and +49A/G polymorphisms in a first cohort of 142 patients with pSS (cohort 1) and 241 controls, all of Caucasian origin. A replication study was performed on a second cohort of 139 patients with pSS (cohort 2). In cohort 1, the CTLA-4 +49A/G*A allele was found on 73% of chromosomes in patients with pSS, compared with 66% in controls (p = 0.036; odds ratio (OR) 1.41, 95% confidence interval (CI) 1.02 to 1.95). No difference in CTLA-4 CT60 allelic or genotypic distribution was observed between patients (n = 142) and controls (n = 241). In the replication cohort, the CTLA-4 +49A/G*A allele was found on 62% of chromosomes in patients with pSS, compared with 66% in controls (p = 0.30; OR 0.85, 95% CI 0.63 to 1.16). Thus, the CTLA-4 +49A/G*A allele excess among patients from cohort 1 was counterbalanced by its under-representation in cohort 2. When the results from the patients in both cohorts were pooled (n = 281), there was no difference in CTLA-4 +49A/G allelic or genotypic distribution in comparison with controls. Our results demonstrate a lack of association between CTLA-4 CT60 or +49A/G polymorphisms and pSS. Premature conclusions might have been made if a replication study had not been performed. These results illustrate the importance of case-control studies performed on a large number of patients. In fact, sampling bias may account for some contradictory results previously reported for CTLA-4 association studies in autoimmune diseases.

Koh MS, Goh KY, Chen C, Howe HS. · Department of Neurosurgery, Singapore General Hospital, Outram Road, Singapore. · Hong Kong Med J. · Pubmed #12167735 links to  free full text

Abstract: A 50-year-old Chinese woman with a chronic 20-year history of ataxic gait associated with dry eyes and mouth, was admitted to hospital after a single episode of syncope. Magnetic resonance imaging scans showed a large left frontal hypodense lesion suggestive of a glioma. Craniotomy was performed and the lesion excised, with histology showing only infarcted tissue and no malignant cells. Further diagnostic evaluation revealed that the patient had primary Sjogren's syndrome, with demyelinating polyneuropathy. In the absence of risk factors for stroke, it was considered likely that the cerebral infarct was secondary to autoimmune-related vasculitis. Functional neuroimaging, such as magnetic resonance spectroscopy, should be considered in evaluating doubtful or unusual brain lesions in patients with autoimmune disease.

Fu C, Yu Y, Chen C. · Institute for Molecular Biology, Bioactive Material Research Laboratory, Nankai University, PR China. · Artif Cells Blood Substit Immobil Biotechnol. · Pubmed #11009113 No free full text.

Abstract: AIM: To develop a novel immunoadsorbent for rheumatoid arthritis (RA) therapy. METHODS: A RA immunoadsorbent was developed by binding heat-aggregated human IgG(HAHIgG) to porous agar gel beads. Its adsorption capacity for rheumatoid factors (RFs), storage stability and blood compatibility were evaluated. RESULTS: The coupling yield of HAHIgG on the carrier was 6.0 mg/g wet gel. Saturation adsorption capacity of the adsorbent for IgMRF, IgGRF and IgARF were 3400, 2240 and 2400 IU/g, respectively. The adsorbent can be stored at 4 degrees C for three months without significant variance in its activity. Its fine permeability and hemocompatibility were demonstrated by extracorporeal hemoperfusion on rabbits. CONCLUSION: HAHIgG/agar gel is a safe and effective immunoadsorbent for RA therapy, its potential clinical use is promising in the future.