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Biomedical subjects

P A Bacon

Publications and source records attributed to P A Bacon.

At least 19 recordsLinked to original sources
PubMed2005

Infliximab leads to a rapid but transient improvement in endothelial function in patients with primary systemic vasculitis.

OBJECTIVE: To assess the immediate effects of tumour necrosis factor alpha (TNFalpha) blockade on endothelial function in systemic vasculitis. METHODS: Endothelial function was assessed by laser Doppler flowmetry in patients with active vasculitis after 10 infusions of infliximab. For comparison endothelial responses were assessed after five infusions of cyclophosphamide plus methylprednisolone. RESULTS: Endothelial dependent vasodilatation (EDV) improved significantly within 24 hours of infliximab infusion. The median change in red blood cell flux (interquartile range) was 5.7 (4.3-8.2) before infusion v 8.4 (7.5-10.9) at 24 hours; p=0.027. This was not maintained at day 14. No improvement was seen in EDV after cyclophosphamide plus methylprednisolone infusion. CONCLUSION: The rapid but transient improvement in EDV after TNFalpha inhibition suggests that TNFalpha may have a direct role in the impairment of endothelial function.

Adult↗
PubMed2005

Endothelial cell dysfunction in systemic vasculitis: new developments and therapeutic prospects.

PURPOSE OF REVIEW: The role of the endothelium as an active player rather than a passive victim of inflammation has received considerable interest in atherosclerosis, but less so in systemic vasculitis (SV). However, the accumulating multi-organ damage seen in SV probably includes the endothelium. Assessment of endothelial function is now a standard clinical research tool in cardio-vascular departments. The exciting insights provided by their application to SV, in both primary disease and connective tissue diseases (CTD), is reviewed here. RECENT FINDINGS: Diffuse endothelial cell dysfunction (ECD) documented by several techniques occurs commonly in adult and childhood SV. Similar ECD is also seen in CTD. The mechanisms probably relate to inflammatory cytokines such as TNF. The particular role of vasculitic, as opposed to synovial or internal organ inflammation, may be release of secondary mediators directly into the blood stream- whence they can reach distant endothelial beds to induce this diffuse ECD. SUMMARY: Endothelial injury is the first step in atherosclerosis, where peripheral abnormalities correlate with coronary artery responses. The diffuse ECD in CTD suggests that vascular inflammation may initiate the accelerated CVS disease there. The new findings of similar ECD in primary SV predicts enhanced atherosclerosis here too. In Kawasaki syndrome, persistent late ECD correlates with abnormal coronary responses. In adult SV, initial data also suggests increased subclinical atherosclerosis. The role of endothelial function in the clinical outcome of SV deserves more attention. Research to pinpoint the mechanisms of ECD should lead to more specific therapies that may ameliorate the continuing late morbidity and mortality of SV.

Connective Tissue Diseases↗
PubMed2004

Use of a corporate needs assessment to define the information requirements of an arthritis resource centre in Birmingham: comparison of patients' and professionals' views.

OBJECTIVES: Education and information are important components of the management of chronic disease, though provision of these in the routine clinic setting may be suboptimal. We carried out a corporate needs assessment, both to evaluate stakeholders' perceived usefulness of potential facilities that could be offered by a community-based arthritis resource centre in Birmingham and to compare the views of patients with rheumatological conditions and health professionals. METHODS: Rheumatology patients (n = 201 responders/309 contacted) and health professionals (n = 232/430) were asked to complete a questionnaire to assess both current rheumatology service provision and perceived needs for further information that could be offered within the proposed resource centre. Views of patients and professionals were compared using odds ratios. Logistic regression analysis determined patient characteristics associated with perceived usefulness of various information types. RESULTS: The overall response rate was 58%. Most patients were currently receiving medication but only 38% received written information on arthritis. Over 80% of responders felt that more information would be useful, particularly information in written leaflets. Compared with professionals, patients gave higher value to certain types of medical, non-medical, support and skills information, particularly individual information from trained volunteers, and specific information on benefits, diet and alternative therapy, and symptom management. Non-Caucasian patients gave higher value to the provision of material in different languages and the availability of multilingual volunteer staff. CONCLUSION: Rheumatology patients and professionals identified a relative lack of information for patients. There was wide interest in the provision of more information, with value placed on the provision of material in different languages, at an educational resource centre. This work has been used to develop the facilities currently offered at the Birmingham Arthritis Resource Centre. Further research is needed to investigate the effectiveness of the provision of good quality information to patients with arthritis.

Adolescent↗
PubMed2004

Autologous stem cell transplantation in the treatment of systemic sclerosis: report from the EBMT/EULAR Registry.

OBJECTIVE: To analyse the durability of the responses after haematopoietic stem cell transplantation (HSCT) for severe systemic sclerosis (SSc) and determine whether the high transplant related mortality (TRM) improved with experience. This EBMT/EULAR report describes the longer outcome of patients originally described in addition to newly recruited cases. METHODS: Only patients with SSc, treated by HSCT in European phase I-II studies from 1996 up to 2002, with more than 6 months of follow up were included. Transplant regimens were according to the international consensus statements. Repeated evaluations analysed complete, partial, or non-response and the probability of disease progression and survival after HSCT (Kaplan-Meier). RESULTS: Given as median (range). Among 57 patients aged 40 (9.1-68.7) years the skin scores improved at 6 (n = 37 patients), 12 (n = 30), 24 (n = 19), and 36 (n = 10) months after HSCT (p<0.005). After 22.9 (4.5-81.1) months, partial (n = 32) or complete response (n = 14) was seen in 92% and non-response in 8% (n = 4) of 50 observed cases. 35% of the patients with initial partial (n = 13/32) or complete response (n = 3/14) relapsed within 10 (2.2-48.7) months after HSCT. The TRM was 8.7% (n = 5/57). Deaths related to progression accounted for 14% (n = 8/57) of the 23% (n = 13/57) total mortality rate. At 5 years, progression probability was 48% (95% CI 28 to 68) and the projected survival was 72% (95% CI 59 to 75). CONCLUSION: This EBMT/EULAR report showed that response in two thirds of the patients after HSCT was durable with an acceptable TRM. Based on these results prospective, randomised trials are proceeding.

Adolescent↗
PubMed2003

Diffuse endothelial dysfunction is common to ANCA associated systemic vasculitis and polyarteritis nodosa.

BACKGROUND: Excess cardiovascular mortality complicates systemic rheumatic disease, suggesting an accelerated atheromatous process, which it has been proposed relates to the vascular inflammation common in such diseases. Impaired endothelium dependent vasodilatation is an early marker of atheromatous disease. It has previously been shown that such endothelial cell dysfunction (ECD) occurring in the brachial artery can complicate primary systemic necrotising vasculitis (SNV). OBJECTIVE: To determine if ECD occurs in a wider spectrum of primary SNV, if it is restricted to the major arteries, and whether vasculitis subgroup, ANCA status, or renal involvement influenced the endothelial responses. METHODS: Fifty four patients attending the Birmingham vasculitis clinic, including patients with a range of ANCA and non-ANCA associated primary vasculitides, and a group of age matched controls were recruited. The length of patient follow up and disease activity was variable. Disease activity, damage scores, and cardiovascular risk factors were recorded before assessment of flow mediated brachial artery vasodilatation by high resolution ultrasound. Dermal microvascular responses to acetylcholine were also measured in 32 patients and 21 controls by laser Doppler flowmetry. RESULTS: ECD was demonstrated in all primary SNV subgroups of patients with ANCA associated vasculitis and in polyarteritis nodosa, compared with controls. Significant impairment occurred in both vascular beds, regardless of vessel size targeted in the inflammatory vasculitis, ANCA association and titre, or renal involvement. CONCLUSIONS: Diffuse endothelial dysfunction, a predictor of atherosclerotic disease, is found extensively in primary systemic vasculitis. Involvement of different vascular beds is independent of target vessel size or ANCA association, and is unrelated to local disease expression. It is suggested that this results from a systemic response that may be a consequence of primary vasculitis, but is distinct from the local inflammatory vasculitic process.

Adult↗
PubMed2003

Nailfold capillary microscopy in healthy children and in childhood rheumatic diseases: a prospective single blind observational study.

OBJECTIVES: To develop an objective method of nailfold capillaroscopy (NFC), applicable to a wide age range of paediatric patients. To compare the morphological characteristics of the nailfold capillaries in different rheumatology patient groups and controls. METHODS: A colour digital video camera attached to a stereomicroscope was used to capture nailfold capillary images. Computerised image processing was used to analyse and store data. Subsequent quantitative and qualitative morphological analysis was performed in the following paediatric patient and control groups: 18 children with connective tissue diseases (CTD: juvenile dermatomyositis, systemic sclerosis, and undifferentiated connective tissue disease), eight with systemic lupus erythematosus, nine with primary Raynaud's disease, three with primary vasculitis, 15 with juvenile idiopathic arthritis, 17 healthy children and 20 healthy adults. Images were analysed by a single assessor who was unaware of the patient details. RESULTS: The NFC technique was simple to perform and gave reproducible results, although some intra- and intersubject variation was noted. Capillary density and width was age related, with younger children having fewer and wider capillaries than older children and adults. Linear capillary density was significantly higher in healthy adults (mean (SD) 8.6 (1.6) capillaries/mm) compared with healthy children (HC 6.9 (0.9) capillaries/mm). The group with CTD had the most abnormal findings, with lower linear density (4.9 (1.7) capillaries/mm) and increased capillary loop width (10.7 (7.3) mm) compared with HC (3.5 (1.7) mm). In addition, 11/18 (61%) patients in the CTD group had more than two definitely abnormal capillaries in at least two nailfolds, an abnormality not seen in other subjects. Two qualitative measures, the degree of avascularity and general disarrangement of capillary pattern, were more commonly observed in the CTD group than in HC. The proportion of tortuous capillaries did not differ significantly between study groups. CONCLUSIONS: This study is unique in measuring objective quantitative and qualitative parameters of the nailfold vasculature across a wide spectrum of age and disease. Differences in capillary morphology and frequency in children with CTD compared with other paediatric diseases and healthy controls were demonstrated. In the clinical situation, an assessment of the general degree of disarrangement may offer a fast tool for assessment of the nailfold vasculature which correlates well with NFC data.

Adolescent↗
PubMed2002

Accelerated atherogenesis in autoimmune rheumatic diseases.

The observation that systemic inflammatory rheumatic diseases such as rheumatoid arthritis (RA) are associated with a significantly increased rate of cardiovascular disease, which often occurs at a younger age than in the normal population, is particularly important given the increasing interest in the role of inflammation in atherogenesis in the general population. This review examines the accumulating evidence for accelerated atherogenesis of RA and updates the hypothesis that vasculitis plays a major role in this. Endothelial dysfunction (ECD), widely regarded as initial lesion in atherogenesis, has been shown to occur commonly in primary vasculitis. This ECD is a diffuse event, demonstrable in more than one vascular bed. It is not simply due to scarring in the vessel wall, related to the focal inflammation of the underlying vasculitis, since it may be reversed by suppression of the immune inflammation. However, the mechanisms for this ECD differ from that of the primary vasculitis. Preliminary evidence suggests that inflammatory mediators such as CRP, TNF, or sphingolipids may be involved. The diffuse ECD of vasculitis may have important consequences for both the progression of the primary disease and for cardiovascular events. A model for the role of vasculitis-induced ECD in the accelerated atherogenesis of rheumatic diseases is presented. These concepts are discussed together with the messages they suggest for 'idiopathic' atherosclerosis in the general population.

Arteriosclerosis↗
PubMed2002

Computerized information-gathering in specialist rheumatology clinics: an initial evaluation of an electronic version of the Short Form 36.

OBJECTIVES: Longitudinal outcome data are important for research and are becoming part of routine clinical practice. We assessed an initial version of an electronic Short Form 36 (SF-36), a well-established health assessment questionnaire, in comparison with standard paper forms, in two specialist rheumatology clinics. METHODS: Out-patients (20 with systemic lupus erythematosus and 31 with vasculitis) were randomly selected to complete either paper (n=29) or electronic and paper SF-36 versions (n=51) before and after consultation (paper vs paper comparison). Data were evaluated as the response correlation, internal consistency, missing data, patient satisfaction and preference. RESULTS: There were very good correlations in SF-36 responses (P<0.001) between the paper and electronic forms and the paper and paper forms. Internal reliability coefficients (Cronbach's alpha) showed good internal consistency for all reported responses in either computer or paper forms. There were no missing data in the computerized version but 24% of patients failed to answer all of the paper form questions. Ease of use of the computer version was rated highly by 71% of all the respondents, and 69% would prefer to use the computer version in future. DISCUSSION: Computerized data collection is acceptable to patients and feasible in clinical settings. It provides responses that are at least comparable to those to the paper form, improves data capture and is available immediately.

Ambulatory Care↗
PubMed2002

Development and assessment of a World Wide Web site for systemic lupus erythematosus patient information.

Patient education is an important component of the management of chronic diseases such as SLE. We have investigated the value of the World Wide Web as a medium for delivery of SLE patient information. Volunteers recruited from the clinic and from the website completed interviews and questionnaires aimed at defining their information needs. A new website was then established and its impact on users tested using knowledge questionnaires. The new website was used extensively (20-30 users each day) over the 24 month period of study until April 2001. A total of 510 participants completed an online questionnaire that showed that for some users it was their first use of the internet to gather lupus information, but the majority (58.9%) accessed it at least monthly for this purpose. We also found that, while most users (56.9%) found current disease information was at an appropriate level, 37.5% thought it was too basic. Knowledge questionnaires from 42 participants before and after using the site showed a significant rise in users' knowledge of the areas covered by the site. As far as we are aware this study is the first to show that a patient-oriented website can have a positive effect on disease knowledge. The relative ease with which good quality information can be disseminated via the web suggests that this medium is likely to be less costly and perhaps more educationally effective than printed information, and so is likely to become a primary vehicle for patient education. The website tested can be found at: www.rheumatology.bham.ac.uk/lupus/intro.html.

Humans↗
PubMed2001

New therapeutic aspects: haemopoietic stem cell transplantation.

Primary systemic vasculitis responds well to intensive immunosuppression, particularly with cyclophosphomide. Use of the latter is restricted by side-effects, particularly in relapsing disease. Techniques which allow more complete immunosuppression have an obvious attraction in autoimmune disease. They are particularly suitable for vasculitis which can go into long-lasting remission even with standard therapy in many cases. The conditioning used for stem cell transplantation allows more complete deletion of auto aggressive T-cell clones, with subsequently haemopoietic rescue by previously harvested stem cell precursors. The procedure also has immune potentiating effects, perhaps by promoting peripheral suppressor mechanisms. These may be important even though immune ablation is not achieved. With rigorous patient selection, experience with this technique in vasculitis may be broadened.

Hematopoietic Stem Cell Mobilization↗
PubMed2001

Provision of Internet-based rheumatology education (http://rheuma.bham.ac.uk).

OBJECTIVES: The Internet is becoming an important way of delivering medical information, and if used appropriately may assist in improving patients' self-management of their disease. We have established an arthritis education website ('Arthritis Help') and investigated its use over the last 2 yr. METHODS: Computer-generated log-file analysis and on-line questionnaires were used to create user profiles of our website. RESULTS: An average of 288 people visited our site each day, predominantly from America and the UK (49% of users). The typical questionnaire respondent (n = 770) was an American female with arthritis, aged 30+ yr, accessing the Internet from home. Typically, respondents had previously obtained information from medical staff or in written form, but were now more likely to use the Internet. One hundred and sixty-seven out of 585 respondents found our site to be useful, prompting them to seek more information (29%), change their behaviour or engage in more effective discussions with their physician (15%). CONCLUSIONS: These data indicate that it is possible to use the Internet to deliver medical information to its target audience, and that this process can have some impact on the way disease is self-managed. This information may aid more focused website design to maximize the use and potential benefits of such a resource.

Age Distribution↗
PubMed2001

Phase I/II trial of autologous stem cell transplantation in systemic sclerosis: procedure related mortality and impact on skin disease.

BACKGROUND: Systemic sclerosis (SSc, scleroderma) in either its diffuse or limited skin forms has a high mortality when vital organs are affected. No treatment has been shown to influence the outcome or significantly affect the skin score, though many forms of immunosuppression have been tried. Recent developments in haemopoietic stem cell transplantation (HSCT) have allowed the application of profound immunosuppression followed by HSCT, or rescue, to autoimmune diseases such as SSc. METHODS: Results for 41 patients included in continuing multicentre open phase I/II studies using HSCT in the treatment of poor prognosis SSc are reported. Thirty seven patients had a predominantly diffuse skin form of the disease and four the limited form, with some clinical overlap. Median age was 41 years with a 5:1 female to male ratio. The skin score was >50% of maximum in 20/33 (61%) patients, with some lung disease attributable to SSc in 28/37 (76%), the forced vital capacity being <70% of the predicted value in 18/36 (50%). Pulmonary hypertension was described in 7/37 (19%) patients and renal disease in 5/37 (14%). The Scl-70 antibody was positive in 18/32 (56%) and the anticentromere antibody in 10% of evaluable patients. Peripheral blood stem cell mobilisation was performed with cyclophosphamide or granulocyte colony stimulating factor, alone or in combination. Thirty eight patients had ex vivo CD34 stem cell selection, with additional T cell depletion in seven. Seven conditioning regimens were used, but six of these used haemoimmunoablative doses of cyclophosphamide +/- anti-thymocyte globulin +/- total body irradiation. The median duration of follow up was 12 months (3-55). RESULTS: An improvement in skin score of >25% after transplantation occurred in 20/29 (69%) evaluable patients, and deterioration in 2/29 (7%). Lung function did not change significantly after transplantation. One of five renal cases deteriorated but with no new occurrences of renal disease after HSCT, and the pulmonary hypertension did not progress in the evaluable cases. Disease progression was seen in 7/37 (19%) patients after HSCT with a median period of 67 (range 49-255) days. Eleven (27%) patients had died at census and seven (17%) deaths were considered to be related to the procedure (direct organ toxicity in four, haemorrhage in two, and infection/neutropenic fever in one). The cumulative probability of survival at one year was 73% (95% CI 58 to 88) by Kaplan-Meier analysis. CONCLUSION: Despite a higher procedure related mortality rate from HSCT in SSc compared with patients with breast cancer and non-Hodgkin's lymphoma, the marked impact on skin score, a surrogate marker of mortality, the trend towards stabilisation of lung involvement, and lack of other treatment alternatives justify further carefully designed studies. If future trials incorporate inclusion and exclusion criteria based on this preliminary experience, the predicted procedure related mortality should be around 10%.

Adolescent↗
PubMed2000

Suppression of inflammation in primary systemic vasculitis restores vascular endothelial function: lessons for atherosclerotic disease?

BACKGROUND: Chronic inflammatory rheumatic disorders are associated with excess cardiovascular mortality. This may result from arteriosclerosis following inflammatory damage to the vessel wall by vasculitis. Our hypothesis that vasculitis results in arteriosclerosis by causing vascular endothelial dysfunction was tested in patients with primary systemic necrotizing vasculitis (SNV). METHODS AND RESULTS: Endothelial function was assessed in cross-sectional and longitudinal studies of patients with primary SNV by measuring flow-mediated, endothelium-dependent brachial artery vasodilatation. These patients exhibited marked endothelial dysfunction compared with controls. Remission induction in patients with active primary SNV restored endothelial function. CONCLUSIONS: Endothelial function is significantly impaired in adults with primary SNV, supporting the hypothesis that premature arteriosclerosis in chronic inflammatory rheumatic disorders results from endothelial dysfunction secondary to vasculitis. Normalization of endothelial function after the treatment of primary SNV suggests that early suppression of disease activity in chronic inflammatory rheumatic disorders may reduce long-term vascular damage. The role of inflammation in atheroma formation is increasingly appreciated; this work raises questions regarding the potential for anti-inflammatory therapy in atherosclerosis itself.

Brachial Artery↗
PubMed2000

Dysregulated intracellular Ca2+ stores and Ca2+ signaling in synovial fluid T lymphocytes from patients with chronic inflammatory arthritis.

OBJECTIVE: Peripheral blood (PB) T cells from rheumatoid arthritis (RA) patients proliferate poorly to mitogen, a change that is related to decreased intracellular Ca2+ ([Ca2+]i) signaling after T cell receptor (TCR) stimulation. We hypothesized that this was, in part, due to the effect of mediators of inflammation and predicted that greater changes in [Ca2+]i signaling would be seen in synovial fluid (SF) T cells. We also examined the mechanisms underlying the altered [Ca2+]i signals. METHODS: Paired PB and SF T cells from patients with chronic inflammatory arthritis were stimulated with mitogen to assess the magnitude of the [Ca2+]i signal in cell populations by fluorometry, the pattern of the [Ca2+]i signal in individual cells in a single-cell ion-imaging system, and the spatial distribution of Ca2+ within intracellular organelles. RESULTS: There was a significantly smaller [Ca2+]i signal after phytohemagglutinin protein stimulation of SF T cells (peak rise in [Ca2+]i signal PB versus SF 200 nM versus 180 nM; P < 0.05). In single SF T cells, a change in the pattern of the [Ca2+]i signal and a reduction in the number of responding cells was seen. These changes were a magnification of those seen in RA PB compared with control PB T cells. The contribution of Ca2+ release from intracellular stores to the final [Ca2+]i signal in PB and SF T cells was equal, but there was a significant increase in the Ca2+ remaining in the endoplasmic reticulum (ER) in SF T cells after TCR activation (PB versus SF 6 nM versus 19 nM; P < 0.05). Non-ER Ca2+ stores were not similarly affected. CONCLUSION: We found abnormalities in the magnitude, pattern, and spatial distribution of [Ca2+]i signaling in T cells from SF of patients with chronic inflammatory arthritis. A reduction in the number of responding SF T cells may partly explain some of our observations. However, we propose that the observed redistribution of SF Ca2+ stores may underlie the altered [Ca2+]i signaling, thus making these cells hyporesponsive to mitogen. The inflammatory environment of the joint and the late stage of differentiation of SF T cells are both likely to contribute to these changes in [Ca2+]i signaling, resulting in aberrant T cell function and promotion of disease chronicity.

Arthritis, Rheumatoid↗
PubMed2000

Increased expression of CD23 in rheumatoid synovitis.

OBJECTIVE: Soluble (s)CD23 is a potent macrophage stimulator. High levels of this molecule have been reported in rheumatoid arthritis (RA) serum. We investigated the expression of CD23 and its ligands in rheumatoid synovial fluid and cells. METHODS: Levels of sCD23, and cellular expression of CD23 and its ligands CD21, CD11b, and CD11c were measured in synovial fluid (SF) of RA patients and in blood of RA patients and controls. RESULTS: SF contained higher levels of sCD23 than either rheumatoid or normal sera (median 4.8, 3.16,and 1.13 ng/ml respectively, p <0.01). Synovial CD23 was found to be expressed principally on macrophages. While little CD21 expression was detected, CD11b and CD11c were both expressed at high levels, particularly on macrophages. CONCLUSIONS: Soluble CD23 is present in high levels in RA synovial fluid. Macrophages appear to be the principal source. Macrophages also express ligands for sCD23, and may therefore also be the targets of this potent pro-inflammatory molecule.

Arthritis, Rheumatoid↗