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Biomedical subjects

V Strand

Publications and source records attributed to V Strand.

At least 73 records · Page 4Linked to original sources
PubMed1998

Biologic agents and immunotherapy in rheumatoid arthritis. Progress and perspective.

Advances in our understanding of rheumatoid synovitis have been coupled with increasingly refined methods from biotechnology to produce promising therapeutic agents. Monoclonal antibodies (MoAbs), recombinant cytokines, cytokine receptor fusion proteins and other biologics have been elevated from the status of novel reagents applied in phase I toxicity trials to, in some cases, substantially evaluated and validated tools awaiting federal regulatory approval. Biologic agents will soon be released for the treatment of patients with RA. We review some of the most promising preclinical work that supports a position of optimism regarding the future of RA. We also speculate on the potential role for biologics in future management of patients with RA.

Arthritis, Rheumatoid↗
PubMed1998

Repeated exposure to an ambient level of NO2 enhances asthmatic response to a nonsymptomatic allergen dose.

We investigated the effects of NO2 and allergen on lung function in a repeated exposure model. For 4 subsequent days, 16 subjects with mild asthma and allergy to birch or grass pollen were exposed at rest to either purified air or 500 microg x m(-3) NO2 for 30 min in an exposure chamber. Four hours later, an individually determined nonsymptomatic allergen dose was inhaled. Lung function (forced expiratory volume in one second (FEV1)) was measured by a portable spirometer at early phase (EP) 15 min after allergen and at late phase (LP) 3-10 h after allergen. Subjective symptoms and medication were followed by diary cards. Asthmatic response was significantly increased after repeated exposure to NO2 and allergen compared to air and allergen. The 4-day mean fall in FEV1 after NO2 was at EP -25% versus -0.4% for air (p=0.02) and at LP -4.4% versus -1.9% for air (p=0.01, ANOVA). An increase in EP response was seen already after a single NO2 exposure (p=0.03). There was a tendency (p=0.07) towards increased night-time symptoms of asthma after NO2 plus allergen. Although the effects were small, the results indicate that a repeated short exposure to an ambient level of NO2 enhances the airway response to a nonsymptomatic allergen dose.

Adult↗
PubMed1998

How Canadian and US rheumatologists treat moderate or aggressive rheumatoid arthritis: a survey.

OBJECTIVE: To determine which second line agents Canadian and US rheumatologists use to treat patients with active rheumatoid arthritis (RA). METHODS: A one page survey was sent by fax or mail to all 263 members of the Canadian Rheumatology Association and 320 members of the American College of Rheumatology (10% random sample weighted by region) known to practice adult rheumatology. The survey asked for first and second treatment preferences in patients with (1) aggressive RA; (2) moderate RA; and (3) aggressive RA failing a trial of methotrexate (MTX) 25 mg. RESULTS: Altogether 231 (87.8%) Canadian and 230 (71.7%) US rheumatologists responded, and 214 responses in each survey were analyzable. In aggressive RA. MTX was the drug of first choice of most Canadian (68.7%) and US (78.5%) rheumatologists. Intramuscular gold was a drug of first choice for 14.5 and 1.9% of Canadians and Americans, respectively. 93.9% of Canadian and 90.2% of US respondents preferred single agents for the treatment of moderate RA. Among US rheumatologists. no clear leader emerged as a single agent alternative for the management of aggressive RA unresponsive to MTX. Most said they would use combination (38.3%) or triple (23.8%) therapy involving MTX plus sulfasalazine and/or hydroxychloroquine. 52.3% of Canadians preferred single agent therapy, with 34.6% choosing gold as an alternative to MTX. CONCLUSION: Canadian and US rheumatologists preferred MTX for the treatment of aggressive RA. Canadian rheumatologists saw a small but significant role for intramuscular gold. No single agent emerged as a clear alternative to MTX among US rheumatologists.

Antirheumatic Agents↗
PubMed1997

Peripheral neutrophils after allergic asthmatic reactions.

The response of peripheral neutrophils was studied in 16 patients with allergic asthma after challenge with birch/grass pollen allergen, in order to identify inflammatory markers associated with only the early asthmatic reaction and those associated with both early and late asthmatic reactions. The allergen challenge proceeded until the patients had an early asthmatic reaction with 100% increase in specific airway resistance. Bronchoconstriction after allergen challenge was monitored hourly over 9 h and finally after 18 h, by measurement of the forced expiratory volume in 1 s. Seven patients had a late reaction, defined as a decrease in forced expiratory volume in 1 s of more than 15%. Blood samples were taken before and 18 h after challenge. After allergen challenge (18 h) the blood concentration of neutrophils in patients with a late asthmatic reaction was 1.4 times higher than before challenge and there was a tendency for increased Fc gamma receptor-mediated chemiluminescence. Lewis X-antigen (CD 15), which is associated with endothelial adhesion and extravasation, significantly decreased at the same time. Neutrophils were incubated with the tetrapeptide arginine-glycine-aspartate-serine before and 18 h after allergen challenge. Both patient groups showed an increased Fc gamma receptor-mediated chemiluminescence and a decreased Fc gamma receptor membrane expression following allergen challenge, suggesting a preactivation. In conclusion, patients with a dual asthmatic reaction show a sustained primed inflammatory response and primed neutrophils compared with patients with only an early reaction when measured after the decline of clinical symptoms provoked by allergen challenge.

Adult↗
PubMed1997

Approaches to the management of systemic lupus erythematosus.

Systemic lupus erythematosus is a difficult disease to study with a variable disease course characterized by exacerbations and remissions. A variety of biologic agents are under investigation as potential treatments for systemic lupus erythematosus, either in murine disease models or in clinical trials. These products are designed to specifically interfere with the following immunologic processes: T-cell activation and T-cell-B-cell collaboration, production of anti-dsDNA antibodies, deposition of anti-dsDNA antibody complexes, complement activation, and deposition, and cytokine activation and modulation. More aggressive interventions include gene therapy and stem-cell transplantation. Recently developed immunomodulators have been studied in patients with systemic lupus erythematosus 2'-Chlorodeoxyadenosine, mycophenolate mofetil, and leflunomide. Additional innovative pharmaceutical treatments include the mild androgen dehydroepiandrosterone, estrogen antagonists, including tamoxifen and selective estrogen receptor modulators, and the prolactin inhibitor bromocriptine. Other promising pharmaceutical interventions include products designed to inhibit synthesis of the proinflammatory mediators: prostaglandins, leukotrienes, and nitric oxide. Although previously regarded as an indication to be avoided in the development of new therapeutics, enthusiasm for studying systemic lupus erythematosus in clinical trials now exists. A variety of biologic and pharmaceutical agents offer promise as potential therapies. As with rheumatoid arthritis, development of these products will benefit from active involvement of rheumatologists and efforts to develop international consensus regarding trial methodology and outcome measures.

Animals↗
PubMed1997

Nitrogen dioxide exposure enhances asthmatic reaction to inhaled allergen in subjects with asthma.

We investigated whether exposure to a low level (490 micrograms/m3) of nitrogen dioxide (NO2) affects bronchial responsiveness to allergen and enhances allergen-induced increase in airway responsiveness to histamine. Eighteen subjects with asthma and allergy to pollen were exposed at rest to either purified air or NO2 for 30 min followed 4 h later by an allergen inhalation challenge. Responsiveness to histamine was measured the day after. Lung function during NO2 exposure and allergen challenge was measured by plethysmography and after exposure by a portable spirometer hourly. The order of exposure to NO2 and air was randomized and separated by at least 2 wk. The asthmatic reaction during the late phase was enhanced by NO2, and peak expiratory flow after allergen challenge was on average 6.6% lower (p = 0.02) after NO2 than after air exposure. The number of subjects having a late asthmatic reaction (fall in FEV1 > 15%) was seven after air and 10 after NO2 (NS). Peripheral blood samples were analyzed for differential cell counts before and after NO2/allergen and serum levels of eosinophil cationic protein (ECP). NO2 effect on lung function was neither associated with an increase in eosinophil numbers nor with ECP levels. NO2 did not affect lung function before allergen challenge, early asthmatic reaction, and allergen-induced increase in responsiveness to histamine. These results indicate that short exposure to an ambient level of NO2 followed several hours later by allergen inhalation enhances allergen-induced late asthmatic reaction.

Administration, Inhalation↗
PubMed1997

Effect of 1 year daily treatment with 400 microg budesonide (Pulmicort Turbuhaler) in newly diagnosed asthmatics.

The aim of this study was to investigate whether treatment with a low daily dose of 400 microg inhaled budesonide (Pulmicort Turbuhaler) in newly diagnosed asthmatics could influence the course of asthma. Seventy five adult patients, mostly with mild asthma, diagnosed during the previous year and bronchial hyperresponsiveness, participated in a double-blind, randomized, parallel-group multicentre study. They were treated with budesonide 200 microg b.i.d. or placebo, delivered via Turbuhaler for 12 months and followed-up for another 6 months without inhaled steroid treatment. Airway function, symptom scores, reactivity to histamine and inflammatory indices in blood were assessed. The mean increase in morning peak expiratory flow (PEF) was 28 L x min(-1) after budesonide treatment compared with no increase in the placebo group (p=0.011). The provocative dose of histamine causing a 20% fall in forced expiratory volume in one second (PD20) (geometric mean) increased in the budesonide group by approximately two doubling dose steps, but not in the placebo group (p=0.0003). The difference between groups with regard to improvement in asthma symptom scores and inflammatory indices did not reach statistical significance. During the 6 month follow-up, the PEF values of the patients who had previously been treated with budesonide decreased by 18 L x min(-1) while the PD20 decreased by approximately one doubling dose step. In conclusion, early treatment with a low dose of budesonide improves airway function and decreases bronchial responsiveness, but the improvements are short-lasting without continued treatment.

Administration, Inhalation↗
PubMed1997

Recommendations for a core set of outcome measures for future phase III clinical trials in knee, hip, and hand osteoarthritis. Consensus development at OMERACT III.

Significant progress has been made in outcome measurement procedures for osteoarthritis (OA) clinical trials, and guidelines have been established by the US Food and Drug Administration, European League Against Rheumatism, the World Health Organization/International League of Associations for Rheumatology, and the Group for the Respect of Ethics and Excellence in Science. However, there remains a need for further international harmonization of measurement procedures used to establish beneficial effects in Phase III clinical trials. A key objective of the OMERACT III conference was to establish a core set of outcome measures for future phase III clinical trials. During the conference, using a combination of discussion and polling procedures, a consensus was reached by at least 90% of participants that the following 4 domains should be evaluated in future phase III trials of knee, hip, and hand OA: pain, physical function, patient global assessment, and, for studies of one year or longer, joint imaging (using standardized methods for taking and rating radiographs, or any demonstrably superior imaging technique). These evidence based preferences, achieved with a high degree of consensus, establish an international standard for future phase III trials and will also facilitate metaanalysis and Cochrane Collaborative Project goals.

Clinical Trials, Phase III as Topic↗
PubMed1996

A double-blind, placebo-controlled study of anti-CD5 immunoconjugate in patients with rheumatoid arthritis. The Xoma RA Investigator Group.

OBJECTIVE: To evaluate the efficacy of an anti-CD5 ricin-linked immunoconjugate (CD5-IC) in patients with rheumatoid arthritis (RA). METHODS: A total of 104 evaluable patients were enrolled in a multicenter, double-blind, multiple-dose, placebo-controlled study of CD5-IC. RESULTS: Treatment with CD5-IC in doses up to 8 mg/m2/day for 4 days in 1 month failed to produce marked or prolonged T cell depletion and was no more effective than placebo in ameliorating disease manifestations. An unexpectedly high placebo response was observed in 48% of the patients. Adverse events were correlated with the dose of CD5-IC, but the treatment was generally well-tolerated. CONCLUSION: At the doses used in this study, CD5-IC was ineffective for treating RA.

Adult↗
PubMed1996

Biologic agents for the treatment of rheumatoid arthritis.

Substantial progress has been made in our understanding of the immune system and immunopathogenesis of rheumatoid arthritis. This knowledge, combined with advances in biotechnology, has resulted in the development of biologic agents to selectively target elements of the immune system participating in the inflammatory response. This article reviews the available data from clinical trials of biologic agents for the treatment of rheumatoid arthritis. Randomized controlled trials comparing administration of a biologic agent to placebo are emphasized. Despite concerns raised by initial trials with these agents, they still offer the most promise as treatments for autoimmune diseases ++such as rheumatoid arthritis.

Antigens, Surface↗
PubMed1996

Immediate and delayed effects of nitrogen dioxide exposure at an ambient level on bronchial responsiveness to histamine in subjects with asthma.

The time-kinetics of NO2 induced effects on bronchial responsiveness are poorly known as most observations have been made shortly after exposure. The aim of this study was to measure nonspecific bronchial responsiveness, lung function and inflammatory markers at different times after NO2 exposure in asthmatics. Nineteen subjects with mild asthma were exposed to either purified air or 488 micrograms.m-3 (0.26 ppm) NO2 for 30 min during intermittent exercise. Airway responsiveness to histamine, specific airway resistance (sRaw) and thoracic gas volume (TGV) were measured 30 min, 5 h, 27 h and 7 days after exposure. Peripheral blood inflammatory mediators and the expression of an adhesion molecule, (Mac1) on granulocytes, were analysed 30 min and 27 h after exposure. Bronchial responsiveness to histamine was significantly increased 5 h after NO2 exposure when compared to air (median provocative dose of histamine required to cause 100% increase of sRaw ((PDsRaw,100%) 110 micrograms after NO2 exposure vs 203 micrograms on air). There was a tendency for an increase after 30 min, which was nonsignificant (median PDsRaw,100% 100 vs 153 micrograms). NO2 exposure did not affect sRaw, but TGV was significantly reduced after exposure. We found an increased expression of Mac-1 on granulocytes 30 min after NO2 exposure when compared to pre-exposure values. No effect was seen on tryptase, eosinophil cationic protein (ECP), or myeloperoxidase (MPO). These results suggest that exposure to an ambient level of NO2 causes a delayed effect on bronchial responsiveness in asthmatics. The increased expression of an adhesion molecule in peripheral blood may indicate a NO2-induced priming of human granulocytes.

Adult↗
PubMed1996

The future use of biologic therapies in combination for the treatment of rheumatoid arthritis.

The complexity of the immune system, exemplified by the pleiotropic effects of many cytokines and the redundancy of regulatory networks controlling immune responses, suggests that single therapeutic interventions will offer transient or less than clinically meaningful benefit. Theoretically, combination therapy using 2 or more biologic agents will modulate important symptomatic and objective manifestations of rheumatoid arthritis (RA). Data from animal models suggest that use of biologic agents in combination can be synergistic and may alter the severity and course of disease. Although combinations of biologic agents have yet to be used in human disease, successful examples employing immunosuppressive agents exist: cyclosporin (CsA) with methotrexate in patients with persistent active RA, as well as azathioprine and/or mycophenolate mofitil with CsA in organ transplantation and acute graft rejection. There are many arguments against the use of combination biologic therapies including acute infusion related toxicities, infection, malignancy, autoimmune manifestations, and expense. While caution dictates that phase I-II clinical trials be performed in patients with longstanding, refractory disease, subsequent trials should be conducted in patients with earlier, more responsive disease. Successful combination biologic therapies must afford sufficient duration of benefit (at least 6, preferably 12 months), cost comparable to approved 2nd line agents, ease of treatment, and an acceptable safety profile.

Animals↗
PubMed1995

American College of Rheumatology. Preliminary definition of improvement in rheumatoid arthritis.

OBJECTIVE: Trials of rheumatoid arthritis (RA) treatments report the average response in multiple outcome measures for treated patients. It is more clinically relevant to test whether individual patients improve with treatment, and this identifies a single primary efficacy measure. Multiple definitions of improvement are currently in use in different trials. The goal of this study was to promulgate a single definition for use in RA trials. METHODS: Using the American College of Rheumatology (ACR) core set of outcome measures for RA trials, we tested 40 different definitions of improvement, using a 3-step process. First, we performed a survey of rheumatologists, using actual patient cases from trials, to evaluate which definitions corresponded best to rheumatologists' impressions of improvement, eliminating most candidate definitions of improvement. Second, we tested 20 remaining definitions to determine which maximally discriminated effective treatment from placebo treatment and also minimized placebo response rates. With 8 candidate definitions of improvement remaining, we tested to see which were easiest to use and were best in accord with rheumatologists' impressions of improvement. RESULTS: The following definition of improvement was selected: 20% improvement in tender and swollen joint counts and 20% improvement in 3 of the 5 remaining ACR core set measures: patient and physician global assessments, pain, disability, and an acute-phase reactant. Additional validation of this definition was carried out in a comparative trial, and the results suggest that the definition is statistically powerful and does not identify a large percentage of placebo-treated patients as being improved. CONCLUSION: We present a definition of improvement which we hope will be used widely in RA trials.

Adult↗
PubMed1995

Innovative treatment approaches for rheumatoid arthritis. Issues in clinical trials of biological agents.

Biological agents have pointed out directions for future research, although none yet are therapies to be employed in the clinic. To date we have administered them at pharmacological; even industrial-strength doses, without demonstrating the desired cell- or diseased-specific effects. There are many issues specific to the clinical development of biological agents which distinguish them from pharmaceutical products. Most are immunologically active; early trials are performed in patients with disease, rather than normal volunteers. This poses multiple challenges: access to an appropriate patient population, as well as effecting immunomodulation without interfering with normal immune surveillance. Species-specificity of the agent may limit the use of preclinical animal models, and the duration of toxicology studies. Immunogenicity may preclude regular re-administration, necessitating prolonged benefit after single or limited treatment courses. Parenteral administration requires more careful monitoring, limits access to the agent, is associated with more expense, and may contribute to the high observed placebo response following treatment with biological agents. Requirements, and our expectations, for clinical benefit are therefore higher with these products than with traditional pharmaceuticals. Despite a scientific rationale and the use of biological markers, it is unlikely that development of a biological agent for the treatment of a chronic auto-immune disease can progress significantly faster than for a traditional pharmaceutical product. It is therefore important, particularly in the treatment of chronic RA, to develop a careful and rational step-by-step clinical development programme and to define the goals of the therapy: anti-inflammatory or symptom modification versus disease modification. Some biological agents may be expensive but safe NSAIDs. Others may treat disease flares. After 'induction therapy', utilizing a biological agent, followed by 'maintenance therapy' with a traditional DMARD agent, we may envisage 'combination chemotherapy', employing multiple biological products targeting different specific immunological aspects of the disease. We must therefore develop biological agents utilizing rigorous clinical trial principles, and follow suggested guidelines.

Animals↗
PubMed1995

Immunologic assessment during treatment of rheumatoid arthritis with anti-CD5 immunoconjugate.

OBJECTIVE: To determine if sustained immunologic effects occurred after treatment of patients with rheumatoid arthritis (RA) with an immunoconjugate of murine anti-CD5 monoclonal antibody with ricin A chain (anti-CD5). METHODS: We measured lymphocyte populations, mitogen induced peripheral blood mononuclear cell (PBMC) stimulation, cytokine levels, immunoglobulin levels, in vivo immune function, and clinical outcomes in 9 patients with RA treated with anti-CD5. RESULTS: The treatment of patients with RA with anti-CD5 was associated with marked acute depletion of peripheral blood lymphocytes (p < 0.01) during and immediately after treatment. A sustained decrease in the number of CD3, CD4, CD5, and CD8 bearing lymphocytes persisted for 2 months after treatment (p < 0.05). After 3 months a mild decrease in the number of these lymphocyte populations persisted, but when compared to baseline values, the differences were not found to be statistically significant. Phytohemagglutinin induced PBMC proliferation was decreased at the 3-month followup (p < 0.05). Evaluations of mitogen induced cytokine and immunoglobulin production, immunoglobulin level, autoantibody, and in vivo antibody response to tetanus toxoid did not show any consistent change from baseline. CONCLUSION: Anti-CD5 treatment of RA appears to be associated with a decrease in the population of cells bearing CD5, but does not appear to induce any persistent immunologic abnormalities.

Adolescent↗