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Brooks P. The modified VAC glove for hand burns. Burns 2007. [DOI: 10.1016/j.burns.2006.10.296] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Pavlick A, Liebes L, Osman I, Brooks P, Yee H, Polsky D, Hamilton A, Wright J, Muggia F. 589 POSTER Alteration of the RAS/BRAF/MEK/MAPK pathway by BAY 43-9006 (sorafenib) in metastatic melanoma. EJC Suppl 2006. [DOI: 10.1016/s1359-6349(06)70594-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022] Open
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Strand V, Conaghan PG, Lohmander LS, Koutsoukos AD, Hurley FL, Bird H, Brooks P, Day R, Puhl W, Band PA. An integrated analysis of five double-blind, randomized controlled trials evaluating the safety and efficacy of a hyaluronan product for intra-articular injection in osteoarthritis of the knee. Osteoarthritis Cartilage 2006; 14:859-66. [PMID: 16626978 DOI: 10.1016/j.joca.2006.02.012] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2005] [Accepted: 02/24/2006] [Indexed: 02/02/2023]
Abstract
OBJECTIVE Five double-blind, randomized, saline-controlled trials (RCTs) were included in the United States marketing application for an intra-articular hyaluronan (IA-HA) product for the treatment of osteoarthritis (OA) of the knee. We report an integrated analysis of the primary Case Report Form (CRF) data from these trials. METHOD Trials were similar in design, patient population and outcome measures - all included the Lequèsne Algofunctional Index (LI), a validated composite index of pain and function, evaluating treatment over 3 months. Individual patient data were pooled; a repeated measures analysis of covariance was performed in the intent-to-treat (ITT) population. Analyses utilized both fixed and random effects models. Safety data from the five RCTs were summarized. RESULTS A total of 1155 patients with radiologically confirmed knee OA were enrolled: 619 received three or five IA-HA injections; 536 received "placebo" saline injections. In the active and control groups, mean ages were 61.8 and 61.4 years; 62.4% and 58.8% were women; baseline total Lequèsne scores 11.03 and 11.30, respectively. Integrated analysis of the pooled data set found a statistically significant reduction (P < 0.001) in total Lequèsne score with hyaluronan (HA) (-2.68) vs placebo (-2.00); estimated difference -0.68 (95% CI: -0.56 to -0.79), effect size 0.20. Additional modeling approaches confirmed robustness of the analyses. CONCLUSIONS This integrated analysis demonstrates that multiple design factors influence the results of RCTs assessing efficacy of intra-articular (IA) therapies, and that integrated analyses based on primary data differ from meta-analyses using transformed data.
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Smyth W, McClean S, Hack C, Ramachandran V, Doherty B, Joyce C, O’Donnell F, Smyth T, O’Kane E, Brooks P. The characterisation of synthetic and natural-product pharmaceuticals by electrospray ionisation-mass spectrometry (ESI-MS) and liquid chromatography (LC)-ESI-MS. Trends Analyt Chem 2006. [DOI: 10.1016/j.trac.2006.04.003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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Abstract
We describe a lethal poisoning in a healthy woman caused by deliberate ingestion of aluminium phosphide (AlP), a pesticide used to kill rodents and insects. Toxicity of AlP and review of cases reported to the National Poisons Information Service (London) 1997-2003 are discussed.
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Philippi A, Roschmann E, Tores F, Lindenbaum P, Benajou A, Germain-Leclerc L, Marcaillou C, Fontaine K, Vanpeene M, Roy S, Maillard S, Decaulne V, Saraiva JP, Brooks P, Rousseau F, Hager J. Haplotypes in the gene encoding protein kinase c-beta (PRKCB1) on chromosome 16 are associated with autism. Mol Psychiatry 2005; 10:950-60. [PMID: 16027742 DOI: 10.1038/sj.mp.4001704] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Autism is a developmental disorder characterized by impairments in social interaction and communication associated with repetitive patterns of interest or behavior. Autism is highly influenced by genetic factors. Genome-wide linkage and candidate gene association approaches have been used to try and identify autism genes. A few loci have repeatedly been reported linked to autism. Several groups reported evidence for linkage to a region on chromosome 16p. We have applied a direct physical identity-by-descent (IBD) mapping approach to perform a high-density (0.85 megabases) genome-wide linkage scan in 116 families from the AGRE collection. Our results confirm linkage to a region on chromosome 16p with autism. High-resolution single-nucleotide polymorphism (SNP) genotyping and analysis of this region show that haplotypes in the protein kinase c-beta gene are strongly associated with autism. An independent replication of the association in a second set of 167 trio families with autism confirmed our initial findings. Overall, our data provide evidence that the PRKCB1 gene on chromosome 16p may be involved in the etiology of autism.
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Boers M, Brooks P, Simon LS, Strand V, Tugwell P. OMERACT: an international initiative to improve outcome measurement in rheumatology. Clin Exp Rheumatol 2005; 23:S10-3. [PMID: 16273779] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
OMERACT is the acronym for an international, informally organized network aimed at improving outcome measurement in rheumatology. Chaired by an executive committee it organizes consensus conferences in a 2-yearly cycle that circles the globe since 2002. Data driven recommendations are prepared and updated by expert working groups. Recommendations include core sets of measures for most of the major rheumatologic conditions. Since 2002 patients have been actively engaged in the process. OMERACT 8 will take place in Malta, May 2006 (www.omeract.org).
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Pavlick AC, Liebes L, Muggia F, Hardin E, Morillo A, Mendoza S, Fry D, Brooks P. Modulation of chemotherapy with para-amino benzoic acid (PABA): Translation from preclinical models to a completed phase I trial. J Clin Oncol 2005. [DOI: 10.1200/jco.2005.23.16_suppl.7557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Bertkau A, MacDonald S, Roth J, Caunt M, Brooks P, Formenti S. Combined effect of para-aminobenzoic acid (PABA) and ionizing radiation in a syngeneic murine model of breast carcinoma. J Clin Oncol 2004. [DOI: 10.1200/jco.2004.22.90140.3189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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Zochling J, March L, Lapsley H, Cross M, Tribe K, Brooks P. Use of complementary medicines for osteoarthritis--a prospective study. Ann Rheum Dis 2004; 63:549-54. [PMID: 15082486 PMCID: PMC1754991 DOI: 10.1136/ard.2003.010637] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
BACKGROUND Patients with osteoarthritis commonly use complementary and alternative medicines (CAM), either as an adjunct to or in place of conventional analgesics. OBJECTIVES To undertake a prospective investigation of the prevalence of CAM use for osteoarthritis and the direct costs incurred. METHODS The subjects were 341 patients with osteoarthritis of the knee or hip drawn from central and northern Sydney, Australia, and comprising 83 community based patients and 258 awaiting joint replacement. Information on CAM use was obtained from prospective three monthly diaries. Variables of interest included health related quality of life scores. Prospective out of pocket costs were recorded over a 12 month follow up period. RESULTS The prevalence of CAM use was 40%, which falls within the range of previous studies. Average annual expenditure on CAM was 32.25 Australian dollars (range 0 to 603.30). CAM users were more likely to be female (odds ratio (OR) 1.8 (95% confidence interval, 1.1 to 3.0)), reported a higher level of bodily pain (OR 0.97 (0.95 to 0.99)), and were less likely to purchase conventional analgesics (OR 3.3 (1.6 to 7.0)), either prescribed or over the counter. Vitamin supplementation was the most common CAM reported, followed by celery extract, fish oils, and garlic extracts. CONCLUSIONS There are no good quality clinical trials to support the use of most preparations purchased by patients with osteoarthritis. There is a need for patient education on the risks and benefits of complementary medicine in osteoarthritis.
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Brooks P. Rational care before rationed care. Intern Med J 2003; 33:210; author reply 210. [PMID: 12680992 DOI: 10.1046/j.1445-5994.2003.00382.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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Rivett AJ, Bose S, Pemberton AJ, Brooks P, Onion D, Shirley D, Stratford FLL, Forti K. Assays of proteasome activity in relation to aging. Exp Gerontol 2002; 37:1217-22. [PMID: 12470834 DOI: 10.1016/s0531-5565(02)00127-4] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Proteasomes play a major role in intracellular protein turnover. They exist in cells in several different molecular forms including 20S proteasomes, 26S proteasomes and PA28-20S proteasome complexes. In this study we have compared the properties of these purified proteasome complexes to try to design assays that will distinguish between the different complexes (26S proteasome, 20S proteasome, PA28-20S proteasome) in cell extracts. Although the different purified complexes were found to have differences in stability, and in their sensitivity to low concentrations of SDS and salt, the results suggest that it is not straightforward to assay selectively for each type of complex in cell extracts. The relative contribution of different proteasome complexes varies in different cell types and there may be other proteases present which hydrolyse the chosen substrate. Proteasome assays carried out under defined conditions allow comparisons of activity in cell extracts as a function of age, but separation by gel filtration on a Superose 6 column was found to be a useful method for determining the level of different proteasome related complexes.
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Brooks P. Successful telehealth--a university perspective. J Telemed Telecare 2002; 7 Suppl 2:2. [PMID: 11747642 DOI: 10.1258/1357633011937137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Carvalhaes GK, Brooks P, Marques CG, Azevedo JAT, Machado MCS, Azevedo GC. Chlorinated components in lime used in production contaminated citrus pulp pellets from Brazil. CHEMOSPHERE 2002; 46:1409-1411. [PMID: 12002468 DOI: 10.1016/s0045-6535(01)00262-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
In order to further understand the contamination of the citrus pulp pellets (CPP) that were exported to Europe in 1997 we examined both contaminated lime and CPP samples for the distribution of polychlorinated biphenyls (PCBs) and chlorinated benzenes (tri-hexa). Standard isotope dilution techniques were applied for all samples, which were analysed by selected ion monitoring high resolution GC-MS. Lime that is used in the production of CPP product is highly contaminated with PCBs and chlorobenzenes.
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Carvalhaes GK, Brooks P, Marques CG, Azevedo JAT, Machado MCS, Azevedo GC. Lime as the source of PCDD/F contamination in citrus pulp pellets from Brazil and status of the monitoring program. CHEMOSPHERE 2002; 46:1413-1416. [PMID: 12002469 DOI: 10.1016/s0045-6535(01)00263-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
After an exhaustive investigation, in 1997 the source of the milk contamination in Germany was traced to citrus pulp pellets originating from Brazil. It has been shown that lime was the source of the PCDD/F contamination of these products. After this conclusion, a continuous monitoring program has been performed over a two year period and the results are presented in this paper. Standard isotope dilution techniques were used for all samples, which were analyzed by selected ion monitoring high resolution GC-MS.
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Moore J, Tyndall A, Brooks P. Stem cells in the aetiopathogenesis and therapy of rheumatic disease. Best Pract Res Clin Rheumatol 2001; 15:711-26. [PMID: 11812017 DOI: 10.1053/berh.2001.0189] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Animal models of autoimmune disease and case reports of patients with these diseases who have been involved in bone marrow transplants have provided important data implicating the haemopoietic stem cell in rheumatic disease pathogenesis. Animal and human examples exist for both cure and transfer of rheumatoid arthritis, systemic lupus erythematosus (SLE) and other organ-specific diseases using allogeneic haemopoietic stem cell transplantation. This would suggest that the stem cell in these diseases is abnormal and could be cured by replacement of a normal stem cell although more in vitro data are required in this area. Given the morbidity and increased mortality in some patients with severe autoimmune diseases and the increasing safety of autologous haemopoietic stem cell transplantation (HSCT), pilot studies have been conducted using HSCT in rheumatic diseases. It is still unclear whether an autologous graft will cure these diseases but significant remissions have been obtained which have provided important data for the design of randomized trials of HSCT versus more conventional therapy. Several trials are now open to accrual under the auspices of the European Bone Marrow Transplant Group/European League Against Rheumatism (EBMT/EULAR) registry. Future clinical and laboratory research will need to document the abnormalities of the stem cell of a rheumatic patient because new therapies based on gene therapy or stem cell differentiation could be apllied to these diseases. With increasing safety of allogeneic HSCT it is not unreasonable to predict cure of some rheumatic diseases in the near future.
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Moore J, Milliken S, Biggs J, Brooks P. Peripheral blood stem cell transplantation for rheumatoid arthritis--Australian experience. J Rheumatol Suppl 2001; 64:8-12. [PMID: 11642509] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/22/2023]
Abstract
Trials of high dose immunosuppression and peripheral blood stem cell transplantation (PBSCT) in patients with severe rheumatoid arthritis (RA) have now commenced based on encouraging data from case reports of patients with coexistent malignancy and animal transplant models. Early case reports in Australia documented the potential for cure of RA in most patients receiving allogeneic or syngeneic transplants. However, the relatively high morbidity and mortality of these procedures has necessitated the use of autologous PBSCT. in accordance with international guidelines released by the EBMT/EULAR working party. Phase I trials in autologous PBSCT have seen substantial remissions of RA in the majority of patients who had previously failed all available therapies. Recurrence of disease occurs in most patients usually within 2 years; however, the use of disease modifying agents after recurrence results in substantial amelioration of the disease, again suggesting a form of "immunomodulation." This observation raises the possibility of maintenance therapy associated with procedure to prolong responses. Other modifications of the procedure are discussed, including T cell depletion of the graft, currently the subject of a randomized trial.
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Donnelly G, Brooks P. Developmental supervision for nurses. CANADIAN JOURNAL OF NURSING LEADERSHIP 2001; 14:8-14. [PMID: 15487378 DOI: 10.12927/cjnl.2001.19125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/01/2023]
Abstract
Developmental supervision is gaining increasing recognition in nursing as a form of clinical supervision that will promote professional growth and ultimately lead to improved patient care. Benner's (1984) model of career development is used as a framework in which to examine appropriate forms of supervision for each developmental stage. Directive, collaborative and non-directive supervision are applied to each of these developmental levels.
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Brooks P, Hochberg M. Outcome measures and classification criteria for the rheumatic diseases. A compilation of data from OMERACT (Outcome Measures for Arthritis Clinical Trials), ILAR (International League of Associations for Rheumatology), regional leagues and other groups. Rheumatology (Oxford) 2001; 40:896-906. [PMID: 11511759 DOI: 10.1093/rheumatology/40.8.896] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Parnis C, Brooks P. Semi-volatile organic compounds in the Campaspe River system (Victoria, Australia). WATER RESEARCH 2001; 35:1861-1868. [PMID: 11337830 DOI: 10.1016/s0043-1354(00)00454-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The levels of semi-volatile organic compounds (SVOCs) in the Campaspe River system, North Central Victoria, Australia, were monitored from January to September 1995, and the environmental trends and sources of these compounds were determined. The land use within particular catchments dictated the complexity of the SVOCs in run-off water. Run-off from native forest contained the greatest number of SVOCs. Soil and ground litter were shown to contain the greatest complexity of SVOCs, mostly terpenes. However, only a small proportion were leached by run-off with the remainder being tightly bound to the soil or volatilizing to the atmosphere. Under the prevailing drought of early 1995, the rivers contained no detectable SVOCs until the first catchment run-off after significant rainfall in May. The maximum complexity and concentration of the SVOCs coincided with extensive run-off after heavy rainfall in June, effecting a surge of SVOCs with the flood peak. Fatty acids, their amides and hydrocarbons made up the majority of the compounds identified and were in the 1-39 micrograms/l concentration range. The levels then diminished as the catchment was flushed by continual run-off. These results support Lake's 1967 hypothesis that natural floodwaters contain a signature of SVOCs entering from the catchment. The downstream passage of these compounds was obstructed by a man-made storage, Lake Eppalock, with only low concentrations of SVOCs (1-3 micrograms/l) in the outflow, displaying no correlation to run-off.
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Welch V, Singh G, Strand V, Fries J, Boers M, Ramey D, Day RO, Brooks P, Tugwell P, Clinch J, Kristjansson B. Patient based method of assessing adverse events in clinical trials in rheumatology: the revised Stanford Toxicity Index. J Rheumatol 2001; 28:1188-91. [PMID: 11361211] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
We describe the progress towards developing a patient rated toxicity index that meets all of the patient-important attributes defined by the OMERACT Drug Safety Working Party. These attributes are frequency, severity, importance to patient, importance to the clinician, impact on economics, impact on activities, and integration of adverse effects with benefits. The Stanford Toxicity Index (STI) has been revised to collect all attributes with the exception of impact on activities. However, since the STI is a part of the Health Assessment Questionnaire (HAQ), impact on activities is collected by the HAQ. In particular, a new question asks patients to rate overall satisfaction, taking into consideration both benefits and adverse effects. The next step in the development of this tool is to ensure that the STI meets the OMERACT filter of truth, discrimination, and feasibility. Although truth and feasibility have been confirmed by comparisons within the ARAMIS database, discrimination needs to be assessed in clinical trials.
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Woodworth TG, Furst DE, Strand V, Kempeni J, Fenner H, Lau CS, Miller F, Day R, Lipani J, Brooks P. Standardizing assessment of adverse effects in rheumatology clinical trials. Status of OMERACT Toxicity Working Group March 2000: towards a common understanding of comparative toxicity/safety profiles for antirheumatic therapies. J Rheumatol 2001; 28:1163-9. [PMID: 11361207] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
This paper describes the background and current status of an OMERACT facilitated effort to improve the consistency of adverse event reporting in rheumatology clinical trials. The overall goal is the development of an adverse event assessment tool that would provide a basis for use of common terminology and improve the consistency of reporting severity of side effects within rheumatology clinical trials and during postmarketing surveillance. The resulting Rheumatology Common Toxicity Criteria Index encompassed the following organ systems: allergic/immunologic, cardiac, ENT, gastrointestinal, musculoskeletal, neuropsychiatric, ophthalmologic, pulmonary and skin/integument. Before this tool is widely accepted, its validity, consistency, and feasibility need to be assessed in clinical trials.
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Lipani JA, Strand V, Johnson K, Woodworth T, Furst D, Singh G, Day R, Brooks P. A proposal for developing a large patient population cohort for longterm safety monitoring in rheumatoid arthritis. OMERACT Drug Safety Working Party. J Rheumatol 2001; 28:1170-3. [PMID: 11361208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/16/2023]
Abstract
This paper proposes the creation of an objectively acquired reference database to more accurately characterize the incidence and longterm risk of relatively infrequent, but serious, adverse events. Such a database would be maintained longitudinally to provide for ongoing comparison with new rheumatologic drug safety databases collecting the occurrences and treatments of rare events. We propose the establishment of product-specific registries to prospectively follow a cohort of patients with rheumatoid arthritis (RA) who receive newly approved therapies. In addition, a database is required of a much larger cohort of RA patients treated with multiple second line agents of sufficient size to enable case-controlled determinations of the relative incidence of rare but serious events in the treated (registry) versus the larger disease population. The number of patients necessary for agent-specific registries and a larger patient population adequate to supply a matched case-control cohort will depend upon estimates of the detectability of an increased incidence over background. We suggest a system to carry out this proposal that will involve an umbrella organization, responsible for establishment of this large patient cohort, envisioned to be drawn from around the world.
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Rivett AJ, Bose S, Brooks P, Broadfoot KI. Regulation of proteasome complexes by gamma-interferon and phosphorylation. Biochimie 2001; 83:363-6. [PMID: 11295498 DOI: 10.1016/s0300-9084(01)01249-4] [Citation(s) in RCA: 101] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Proteasomes play a major role in non-lysosomal proteolysis and also in the processing of proteins for presentation by the MHC class I pathway. In animal cells they exist in several distinct molecular forms which contribute to the different functions. 26S proteasomes contain the core 20S proteasome together with two 19S regulatory complexes. Alternatively, PA28 complexes can bind to the ends of the 20S proteasome to form PA28-proteasome complexes and PA28-proteasome-19S hybrid complexes have also been described. Immunoproteasome subunits occur in 26S proteasomes as well as in PA28-proteasome complexes. We have found differences in the subcellular distribution of the different forms of proteasomes. The gamma-interferon inducible PA28 alpha and beta subunits are predominantly located in the cytoplasm, while 19S regulatory complexes (present at significant levels only in 26S complexes) are present in the nucleus as well as in the cytoplasm. Immunoproteasomes are greatly enriched at the endoplasmic reticulum (ER) where they may facilitate the generation of peptides for transport into the lumen of the ER. We have also investigated the effects of gamma-interferon on the levels and subcellular distribution of inducible subunits and regulator subunits. In each case gamma-interferon was found to increase the level but not to alter the distribution. Several subunits of proteasomes are phosphorylated including alpha subunits C8 (alpha7) and C9 (alpha3), and ATPase subunit S4 (rpt2). Our studies have shown that gamma-interferon treatment decreases the level of phosphorylation of proteasomes. We have investigated the role of phosphorylation of C8 by casein kinase II by site directed mutagenesis. The results demonstrate that phosphorylation at either one of the two sites is essential for the association of 19S regulatory complexes and that the ability to undergo phosphorylation at both sites gives the most efficient incorporation of C8 into the 26S proteasome.
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