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Background Smoking remains prevalent after cardiovascular disease (CVD) events and knowledge on how to facilitate effective cessation in clinical practice is needed. Purpose To test the effect of an in-hospital nurse-led intervention on the participation rate at municipal Healthy Life Centres (HLC) and the use of smoking cessation drugs. Secondary, to determine long-term effects on cessation rates. Methods A prospective, randomized, open-label, parallel-group intervention pilot-study was conducted at a Norwegian secondary care hospital in 2021. Patients with atherosclerotic CVD who smoked at least one cigarette daily when admitted with an acute CVD event were consecutively included. The nurse-led intervention included cessation counselling utilizing motivational interview technique, information and guidance in proper use of cessation drugs and direct referral to a 12-weeks digital (video ± phone) HLC program where patients received free cessation drugs. The low-threshold intervention included written information about the offer in the HLC with free cessation drugs. The primary endpoints were between-group differences in attendance rates at the HLC program and the use of cessation drugs. Results Of 99 potential participants, 24 did not meet the entry criteria whereas 17 declined to participate. Of 58 randomised patients, three died during follow-up and 55 completed the study. Mean age was 65.7 (SD 9.2) years, 35% were female, 88% had low education, 88% had smoked >20 years, and motivation for quitting smoking was high (mean 8.5 on a 0 [no motivation] to 10 [high motivation] Likert scale). Comorbidity was common (mean Charlson score 5.1) and 40% had symptoms of anxiety and/or depression. The nurse-led intervention resulted in significantly higher participation rate at the HLC (48% vs. 4%, difference: 44% [95% CI: 24%, 65%], P Conclusion Among multi-morbid patients hospitalised for a CVD event, a nurse-led intervention resulted in substantially higher participation rate at a municipal HLC program and higher use of smoking cessation drugs compared to written information. We also found clinically significant long-term effects on cessation rates which needs to be confirmed in a large-scale study. Funding Acknowledgement Type of funding sources: Foundation. Main funding source(s): Dam Foundation

Funding Acknowledgements Type of funding sources: None. Background Insomnia is highly prevalent in coronary heart disease (CHD) patients. However, the potential effect of insomnia on the risk of recurrent major adverse cardiovascular events (MACE) remains uncertain. Purpose To estimate the prospective association of insomnia and the risk of recurrent MACE in a CHD population from routine clinical practice. Methods This prospective cohort study included 1082 consecutive patients 2-36 (mean 16) months after a myocardial infarction and/or a coronary revascularization procedure. Data on insomnia, coronary risk factors and comorbidity were collected at baseline. Insomnia was assessed by Bergen insomnia scale (BIS), based on sleep symptoms per week during the past three months. BIS is constructed from the clinical diagnostic criteria for primary insomnia in DSM-IV TR. The primary composite endpoint of MACE defined as cardiovascular death, hospitalization due to myocardial infarction, revascularization, stroke or heart failure was obtained from the hospital records on average 4.2 (SD 0.3) years after the baseline study. Data were analysed using Cox proportional hazard regression on a multiple imputated dataset stratified by prior coronary events. Results At baseline, mean age was 62 (range 31-80) years, 21% were females, 90% were revascularized, 47% had participated in cardiac rehabilitation and the prescription rate of antiplatelets (97%) and statins (93%) were high. A total of 364 MACE (21%, 95% CI 19%-24%) occurred in 225 patients, including 39 CV deaths. Almost half of the patients (45%) suffered from insomnia at baseline and 24% used sleep medication the past week. For insomnia, the relative risk (RR) of recurrent MACE was 1.62 (95% confidence interval (CI) 1.24-2.11, p-value Conclusions Insomnia was associated with increased risk of recurrent MACE in this prospective cohort following CHD patients from routine clinical practice. The association remained significant even after adjustments for the major coronary risk factors, comorbidity and symptoms of anxiety and depression, indicating that the effects of insomnia is not mediated through poor risk factor control and other psychosocial factors alone. These results emphasize the importance of identifying patients with insomnia as part of coronary rehabilitation.

Funding Acknowledgements Type of funding sources: Foundation. Main funding source(s): Kristin S. Torgersen received founding from the University of Oslo, Research Council of Norway. Introduction The mechanisms linking type D personality to cardiac prognosis in terms of major adverse cardiac events (MACE) and the association between Type D and MACE after controlling for symptoms of anxiety and depression is largely unknown. Propose To investigate the relationship between Type D personality and the Type D characteristics of negative affectivity (NA) and social inhibition (SI) and i) cardiovascular risk factors and ii) risk of recurrent MACE in CHD outpatients. Methods This prospective multicenter cohort study included 1083 patients 2-36 (mean 16) months after a myocardial infarction and/or a revascularization procedure. At baseline, patients underwent a clinical examination and answered a questionnaire including assessment of Type D personality (DS14), anxiety and depression (Hospital Anxiety and Depression Scale (HADS), medication adherence and risk factors (hypertension, smoking, diabetes, low physical activity, waist circumference, low-density lipoprotein cholesterol and C-reactive Protein). The primary composite endpoint of MACE defined as cardiovascular death, hospitalization for myocardial infarction, revascularization, stroke/transitory ischemic attacks or heart failure were obtained from hospital records on average 4.2 (SD 0.4) years after baseline. Data were analyzed by Cox proportional hazard regression stratified for prior coronary events. Results The prevalence of Type D was 18% at baseline. Type D patients were younger at the index event (59.3 vs 62.1 years, p= 0.001), more likely to be female (26.4 vs 19.8 %, p=0.038), scored higher on HADS anxiety (8.4 vs 3.9, p < 0.001), HADS depression (3.2 vs 7.0, p Conclusions Type D personality was only associated with low medication adherence and smoking which may represent potential mechanisms linking type D to cardiovascular prognosis. In our study, only negative affectivity was associated with MACE, suggesting that this is the most important type D characteristic for prognosis. However, NA was no longer associated with MACE after adjusting for anxiety and depression raising the question whether NA, depression and anxiety may have common underlying factors or are overlapping constructs.

BackgroundInfiltration of monocyte-derived macrophages into the synovial tissue (ST) is a hallmark of rheumatoid arthritis (RA) pathology. These macrophages promote inflammation, local joint effusion, and joint damage via the release of cytokines, oxygen reactive species, and tissue damaging enzymes. However, balancing these, are the ‘regulatory’ macrophages with inflammation-resolving properties, characterised by expression of CD206 and MerTK, dominant within the ST of healthy individuals as well as RA patients in remission (1). Indeed, these cells are believed to actively contribute to the maintenance of remission.Macrophages are known to exhibit remarkable phenotypic plasticity and understanding the role of this characteristic in regulating inflammation and pathology remains a major challenge, as does the characterization of factors in the microenvironment such as the synovium that control such macrophage characteristics. Importantly, whether the infiltrating, inflammatory macrophages of the RA ST similarly exhibit such phenotypic plasticity, and whether this occurs during the process of reaching remission, remains to be studied.ObjectivesWe investigated the phenotypic plasticity of inflammatory synovial macrophages from patients with RA in vitro, investigating their ability to convert from an inflammatory macrophage population into ‘regulatory’ CD206+MerTK+ macrophages. These findings will provide a proof-of-concept as to the utility of these macrophage for a cell-based therapy in resolving inflammation in patients with RA, and will likely extend our understanding of the mechanisms of action of currently used therapeutics.MethodsSynovial fluid (SF) mononuclear cells were obtained from patients with active early RA (+ MerTK+ macrophages measured.Figure 1.Synovial fluid CD68+macrophage plasticity in vitro. (A) Gating strategy depicting CD68+ CD45+CD14+ SF macrophage determination. (B) Proportions of CD206 and MerTK-expressing SF macrophages after 48hr culture in the presence of 10 ng/mL IFNγ, 50 ng/mL dexamethasone or 10 µg/mL Infliximab, or absence. Data are representative of 5 individual experiments. Data were analysed by two-way ANOVA followed by Dunnett’s multiple comparison test, *pResultsPrior to culture, the CD68+ macrophage populations present in SF were found to be predominantly CD206-MerTK-. After 48 hours of culture, in the absence of any stimulus, there was an increase in proportions of CD206+MerTK+ macrophages. Treatment with either dexamethasone or anti-TNF (Infliximab) resulted in a further increase in proportions of CD206+ MerTK+, M2-like macrophages. In contrast, culture with IFNγ induced a reduction in this population. Importantly, we found that the generated CD206+MerTK+ macrophages were phenotypically stable in culture following removal of these differentiating agents.ConclusionOur findings demonstrate that inflammatory SF cells are indeed able to polarise to regulatory, CD206+MerTK+ macrophages in vitro. The findings provide further mechanistic insights into the basis for the therapeutic benefits of glucocorticoids and TNF inhibitors, as well as providing initial proof-of-concept in the use of regulatory macrophages as a cellular-based therapy or therapeutic target for patients with RA.References[1]Alivernini S, MacDonald L, Elmesmari A, et al., Distinct synovial tissue macrophage subsets regulate inflammation and remission in rheumatoid arthritis. Nature Medicine. 2020;26(8):1295-306 10.1038/s41591-020-0939-8.Disclosure of InterestsNone declared

BackgroundImmune checkpoint inhibitors (ICIs) are associated with rheumatic and musculoskeletal immune-related adverse events (irAEs) in 5%–20% of patients. Currently, patients refractory to corticosteroids and conventional disease-modifying antirheumatic drugs (cDMARD) are treated with biological DMARDs (bDMARDs) targeting tumor necrosis factor α (TNFα) and interleukin-6, although without a clear biological rationale. Synovial tissue (ST) biopsy presents a valuable opportunity to investigate irAE pathogenesis and appropriately stratify bDMARD use in refractory irAE patients.Case presentationWe provide the first report of comparative, parallel ST and synovial fluid (SF) analyses of severe, cDMARD-refractory, seronegative polyarthritis, classified as a grade 3 irAE occurring in response to nivolumab treatment for metastatic squamous cell lung cancer, in comparison with ST and SF from patients with untreated rheumatoid arthritis (RA). We investigated immunohistochemical labeling of ST cytokine expression as a biological rationale for selecting therapy. Flow cytometric analysis of lymphocytes from ST, SF and blood collected before and after synovial biopsy-guided therapy, in comparison with RA, were evaluated for insights into the immunopathogenesis of irAE. Immunolabeling of ST demonstrated an excess of TNFα cytokine expression. Subsequent treatment with infliximab resulted in resolution of inflammatory symptoms and a significant reduction in C reactive protein levels. Flow cytometric analysis of synovial infiltrates indicated absence of programmed cell death protein-1 (PD-1) receptor positivity despite cessation of nivolumab approximately 200 days prior to the analyzes.ConclusionsA deeper understanding of the immunopathogenetic basis of immune activation in irAEs is required in order to select therapy that is likely to be the most effective. This is the first report investigating parallel blood, ST and SF in ICI-induced severe rheumatic irAE. Use of a bDMARD directed by the dominant inflammatory cytokine achieved resolution of synovitis while maintaining cancer remission.

Background The relative importance of lifestyle, medical and psychosocial factors on the risk of recurrent major cardiovascular (CV) events (MACE) in coronary patients’ needs to be identified. The main objective of this study is to estimate the association between potentially preventable factors on MACE in an outpatient coronary population from routine clinical practice. Methods This prospective follow-up study of recurrent MACE, determine the predictive impact of risk factors and a wide range of relevant co-factors recorded at baseline. The baseline study included 1127 consecutive patients 2–36 months after myocardial infarction (MI) and/or revascularization procedure. The primary composite endpoint of recurrent MACE defined as CV death, hospitalization due to MI, revascularization, stroke/transitory ischemic attacks or heart failure was obtained from hospital records. Data were analysed using cox proportional hazard regression, stratified by prior coronary events before the index event. Results During a mean follow-up of 4.2 years from study inclusion (mean time from index event to end of study 5.7 years), 364 MACE occurred in 240 patients (21, 95% confidence interval: 19 to 24%), of which 39 were CV deaths. In multi-adjusted analyses, the strongest predictor of MACE was not taking statins (Relative risk [RR] 2.13), succeeded by physical inactivity (RR 1.73), peripheral artery disease (RR 1.73), chronic kidney failure (RR 1.52), former smoking (RR 1.46) and higher Hospital Anxiety and Depression Scale-Depression subscale score (RR 1.04 per unit increase). Preventable and potentially modifiable factors addressed accounted for 66% (95% confidence interval: 49 to 77%) of the risk for recurrent events. The major contributions were smoking, low physical activity, not taking statins, not participating in cardiac rehabilitation and diabetes. Conclusions Coronary patients were at high risk of recurrent MACE. Potentially preventable clinical and psychosocial factors predicted two out of three MACE, which is why these factors should be targeted in coronary populations. Trial registration Registered at ClinicalTrials.gov: NCT02309255. Registered at December 5th, 2014, registered retrospectively.

Background Regular assessment and management of lifestyle, biological and psychosocial factors are recommended in coronary patients. The relative importance of these factors on risk of recurrent cardiovascular (CV) events in the outpatient coronary population is not well known. Purpose To estimate the relative effect of potentially modifiable risk factors on recurrent CV events in coronary patients from routine clinical practice. Methods A prospective cohort multicenter study from Norway included 1127 (21% women, 83% participation rate) consecutive patients aged 18–80 years 2–36 (mean 16) months after myocardial infarction and/or a coronary revascularization procedure. Thirty percent had at least one coronary event prior to the index event. The primary composite endpoint of recurrent major adverse CV events (MACE): myocardial infarction, revascularization, stroke, heart failure or cardiovascular death was obtained from the hospital records. Cox proportional hazard models stratified for 1 vs. 2+ previous coronary events were performed with model 1 adjusting for age and model 2 with add-on for coronary risk factors and CV comorbidity. Results At baseline 99% used platelet inhibition, 93% were taking antihypertensive agents and statins, and 45% had participated in cardiac rehabilitation (CR). During follow-up of mean 4.2 (SD 0.3) years, a total of 355 MACE occurred in 240 patients corresponding to a MACE risk of 31.5%. In model 1, smoking, insufficient physical activity, diabetes, not taking statin therapy, no participation in CR, peripheral artery disease (PAD), previous stroke, kidney failure and higher anxiety and depression scores were significantly associated with recurrent MACE (Table). In model 2, smoking, no physical activity, not taking statin, PAD, kidney failure, anxiety and depression remained significant. Conclusions Coronary patients in routine clinical practice were at significant risk of recurrent MACE, particularly in the presence of CV comorbidity. Not taking statin therapy, insufficient physical activity, smoking, anxiety and depression were the major potentially modifiable factors contributing to CV risk. Preventive efforts that target these factors are required to further reduce CV risk in the coronary population. Acknowledgement/Funding Grants from the Norwegian ExtraFoundation for Health and Rehabilitation and Vestre Viken Trust

Background Although immunological blockade of checkpoint inhibitors (CIs) for cancer therapy is known to be associated with exacerbated inflammation recapitulating many features of autoimmunity1, including synovitis resembling rheumatoid arthritis (RA)2, no reports have investigated cellular infiltrates in synovial tissue (ST) of these patients. Here we provide the first report on ST cell infiltration, in particular PD1 expressing T cells, after a PD1 inhibitor-induced (Nivolumab) immune related adverse event (irAE) and severe synovitis. Objectives To characterise ST cellular infiltration in PD1 inhibitor induced arthritis with particular reference to PD1 positive T cells and compare these changes with active early RA ST. Methods Arthroscopic ST biopsies, parallel synovial fluid (SF) and PBMCs were collected from a DMARD-naive nivolumab-treated small cell lung cancer (SCLC) patient with severe peripheral inflammatory polyarthritis (negative RF and ACPA; no axial or extra-articular irAE); 3 DMARD-naive patients with seropositive early RA ( Serial sections from fresh-frozen ST blocks were stained with H and E, CD3, CD45RO, CD55 and CD68 and semi-quantitatively scored as described3. ST, SF and PBMC cell suspensions were stained with Zombie UV (BioLegend), CD45RO, PD1, CD3, ICOS, CD8, CD4, CD20 (all BD) prior to flow cytometry. Cells were gated on live, singlet, lymphocytes, CD3+ and CD4+ T cells, and CD20+ and CD8+ T cells were excluded from endpoint PD1+, ICOS+ and CD45RO+analysis. Results CD68 +macrophage, CD20+ B cell and CD3+ T cell and CD45RO+memory T cell infiltration in IC-irAE was comparable to RA ST on semi-quantitative scoring, while TNF; staining was markedly elevated in CI-irAE compared to RA (CI-irAE-TNF; 4, RA-TNF; 2). Flow cytometry identified a striking absence of PD1+ ICOS+ CD4+T cells in IC-irAE SCLC in all compartments (CI-irAE: ST; 0.06, SF; 0.01, PBMCs; 0.00) compared to RA (RA: ST mean and SEM; 22.13±3.63: SF; 45.95±1.85: and to a lesser extent in PBMCs; 0.41±0.13: n=3 for each), despite comparable CD4 +T cell frequency in each compartment (frequency of CD3 +cells, CI-irAE: ST; 57.8, SF; 64.7, PBMCs; 38.2, RA: ST; 45.9±15.3, SF; 49.5±11.2, PBMCs; 62.2±13.8, figure 1). Figure 1 PD-1 +ICOS + T cells are absent in CI-irAE. Showing the PD-1 +ICOS + frequency of CD4 +T cells gated on live, singlet, lymphocytes, and CD3+, CD20- and CD8-cells. (RA: ST mean and SEM; 22. 13±3.63: SF; 45.95±1.85 n=3 for each, CI-irAE: ST; 0.06, SF; 0.01, PBMCs; 0.00, n=1 for each). Conclusions While ST infiltration in CI-irAE SCLC recapitulates many features of RA histopathology, PD1 expression principally distinguishes RA from irAE ST T-cell infiltration. Despite abundant CD4 and CD45RO memory T cell infiltration in CI-irAE comparable with RA, we found a conspicuous absence of PD1 positive T-cells. Further research is needed to fully understand the nature of reduced PD1 expression in this setting and the source of elevated TNF, which could shed light on the pathogenesis of CI-irAE and guide CI-irAE management. References [1] van der Vlist, et al. Immune checkpoints and rheumatic diseases: what can cancer immunotherapy teach us?Nat Rev Rheumatol2016. [2] Naidoo, J. et al. Inflammatory Arthritis: A Newly Recognized Adverse Event of Immune Checkpoint Blockade. Oncologist2017. [3] Tak, P. P. et al. Analysis of the synovial cell infiltrate in early rheumatoid synovial tissue in relation to local disease activity. Arthritis Rheum. 1997. Disclosure of Interest None declared

Objectives This study sought to investigate the genome-wide transcriptional effects of a combination of disease modifying anti-rheumatic drugs (tDMARD; methotrexate, sulfasalazine and hydroxychloroquine) in synovial tissues obtained from early rheumatoid arthritis (RA) patients. While combination DMARD strategies have been investigated for clinical efficacy, very little data exists on the potential molecular mechanism of action. We hypothesized that tDMARD would impact multiple biological pathways, but the specific pathways were unknown. Methods Paired synovial biopsy samples from early RA patients before and after 6 months of tDMARD therapy were collected by arthroscopy (n = 19). These biopsies as well as those from subjects with normal synovium (n = 28) were profiled by total RNA sequencing. Results Large differences in gene expression between RA and control biopsies (over 5000 genes) were identified. Despite clinical efficacy, the expression of a restricted set of less than 300 genes was reversed after 6 months of treatment. Many genes remained elevated, even in patients who achieved low disease activity. Interestingly, tDMARD downregulated genes included those involved in T cell activation and signaling and plasmablast/plasma cell differentiation and function. Conclusions We have identified transcriptomic signatures that characterize synovial tissue from RA patients with early disease. Analysis after 6 months of tDMARD treatment highlight consistent alterations in expression of genes related to T cell activation and plasmablast/plasma cell differentiation. These results provide novel insight into the biology of early RA and the mechanism of tDMARD action and may help identify novel drug targets to improve rates of treatment-induced disease remission.

Meteorin-like(IL-41), is a novel cytokine that is thought to be immunoregulatory and is highly expressed in psoriatic skin. We investigated IL-41 protein expression in synovial tissue in RA(Rheumatoid Arthritis), PsA(Psoriatic Arthritis) and OA(Osteoarthritis) patients and evaluated IL-41 production from healthy enthesis samples, as the enthesis represent the primary inflammatory site in PsA. IL-41 was measured in synovial fluid from PsA, RA and OA patients. Synovial biopsies were stained for IL-41 by immunohistochemistry. IL-41 was highly expressed in the synovial fluid and synovial tissue of PsA patients (median = 7722 pg/ml) when compared to OA patients (median = 5044 pg/ml). We found that entheseal stromal cells were the dominant producer of IL-41 from the enthesis. Moreover, stromal derived IL-41, could be further induced by IL-17A/F and TNF. In conclusion, IL-41 is expressed in PsA synovium and is present and inducible at the enthesis. Its functional effect in psoriatic inflammation remains to be fully elucidated.

The digital receiver/exciter (DREX) is a key enabling technology for next-generation affordable phased arrays. The goal is an eventual "all-digital" array solution employing a DREX at each array element. Wideband dual-polarized performance is highly desirable for increased radar target resolution, improved target identification, counter-counter measures, and higher data rates for communications applications. An affordable S-band radar DREX architecture is presented, consisting of a digital module, containing a low-cost field-programmable gate array (FPGA), analog-to-digital converter (ADC) and digital-to-analog converter (DAC) electronics, as well as a single-stage frequency converter employing low-cost components. Multi-channel synchronization, per-channel data storage, and back-end inphase/quadrature (I/Q) data flow and digital beamforming are discussed. Applications include radar, communications, and electronic warfare.

This paper presents a design tradeoff for an affordable Ku-band Low-Profile and Wideband Satellite Communication Antenna (LPWSA). The design is a hybrid phased-array antenna to be used as an airborne satellite communications (SATCOM) terminal with reduced height and improved low-angle coverage. The initial objective is to develop a feasible concept and simulate performance of a dual-band and dual-linearly polarized Ku-band antenna with simultaneous transmit and receive. The SATCOM antenna requirements are presented, along with simulations results for various antenna configurations, demonstrating improved gain performance at low-angle coverage by employing a novel "tilted louver array (TLA)" concept.

We review the influence of Paul E. Mayes on broadband antennas and its applications, especially on super-resolution microwave imaging and inverse scattering.

BACKGROUND AND PURPOSE Aortic valve stenosis (AVS) is associated with significant cardiovascular morbidity and mortality. To date, no therapeutic modality has been shown to be effective in retarding AVS progression. We evaluated the effect of angiotensin-converting enzyme inhibition with ramipril on disease progression in a recently developed rabbit model of AVS. EXPERIMENTAL APPROACH The effects of 8 weeks of treatment with either vitamin D2 at 25 000 IU for 4 days a week alone or in combination with ramipril (0.5 mg·kg−1) on aortic valve structure and function were examined in New Zealand white rabbits. Echocardiographic aortic valve backscatter (AVBS) and aortic valve : outflow tract flow velocity ratio were utilized to quantify changes in valve structure and function. KEY RESULTS Treatment with ramipril significantly reduced AVBS and improved aortic valve : outflow tract flow velocity ratio. The intravalvular content of the pro-oxidant thioredoxin-interacting protein was decreased significantly with ramipril treatment. Endothelial function, as measured by asymmetric dimethylarginine concentrations and vascular responses to ACh, was improved significantly with ramipril treatment. CONCLUSIONS AND IMPLICATIONS Ramipril retards the development of AVS, reduces valvular thioredoxin-interacting protein accumulation and limits endothelial dysfunction in this animal model. These findings provide important insights into the mechanisms of AVS development and an impetus for future human studies of AVS retardation using an angiotensin-converting enzyme inhibitor.

OBJECTIVES RA is characterized at the synovial tissue level by synovial lining hyperplasia, angiogenesis and mononuclear cell infiltrates. A failure of apoptotic pathways may explain these pathological changes in RA synovial tissue. This study aims to demonstrate the presence of initiators and inhibitors of apoptosis in RA synovial tissue and the effect of treatment with DMARDs on apoptotic pathways in RA. METHODS Synovial biopsy specimens were obtained at arthroscopy from 16 RA patients before and at 3- or 6-month intervals after commencing treatment with a DMARD. Apoptosis (by the terminal deoxynucleotidyl transferase mediated dUTP nick end labelling method and polyADP-ribose polymerase staining), proteins regulating apoptosis [Fas, FADD-like IL1b converting enzyme inhibitory protein (FLIP), Bcl-2, Survivin and X-linked inhibitor of apoptosis protein (XIAP)] and the presence of activated caspases (caspases 3 and 8) were detected by immunohistochemistry and quantified using image analysis and semiquantitative techniques. RESULTS Fifteen patients responded to treatment, with an ACR response of > or =20%, 13 achieving an ACR response of > or =50% and 3 achieving an ACR remission. There was a significant reduction in SM macrophages and memory T cells, with an increase in fibroblast-like synovial lining cells following DMARD treatment. Apoptosis was not detected in the inflamed synovial tissue of RA patients before starting treatment, despite evidence of caspase activation, but was detectable after successful treatment with DMARDs. Inhibitors of activated caspases (FLIP, Survivin and XIAP) were detected in RA synovial tissue and were down-modulated with successful DMARD treatment. CONCLUSIONS Apoptotic pathways are defective in RA synovial tissue from patients with active disease, despite the presence of activated caspases, possibly due to the abundant expression of inhibitors of the caspase pathway in RA synovial tissue. DMARD treatment can modulate apoptosis in the RA SM, which may lead to restoration of the SM architecture towards that of normal synovial tissue.

Objectives: To compare receptor activator of NF-κB ligand (RANKL) production in the synovial tissue from patients with active rheumatoid arthritis (RA), inactive RA, spondyloarthropathies (SpA), osteoarthritis, and from normal subjects. In addition, to establish the cell lineages expressing RANKL in these tissues. Methods: Immunohistological analysis of frozen synovial tissue biopsy specimens was performed using a monoclonal antibody (mAb) to detect RANKL. Sections were evaluated by computer assisted image analysis and semiquantitative analysis to compare RANKL expression between groups. Dual and sequential labelling with mAb RANKL and cell lineage specific monoclonal antibodies were used to determine the types of cells expressing RANKL. Results: Higher levels of RANKL were expressed in tissues from patients with active RA and SpA than in tissues from patients with inactive RA, osteoarthritis, and from normal subjects. RANKL protein was associated with CD3 antigen-positive lymphocytes and some macrophages. RANKL was predominantly associated with activated, memory T cells (CD45Ro positive cells) in patients with active RA and spondyloarthropathy (SpA). Conclusions: The highest levels of RANKL were detected in patients with RA with active synovitis and in some patients with SpA. An increase in RANKL in the inflamed joint of patients with RA, produced by infiltrating activated T cells and macrophages, is likely to be an important cause of joint erosions in RA.

Objectives. To document the change in synovial membrane macrophage and T-lymphocyte content in rheumatoid arthritis (RA) patients who achieve remission induced by diseasemodifying anti-rheumatic drugs (DMARDs). Methods. Arthroscopic synovial biopsies were taken from four to seven sites around a knee joint in 13 patients with RA before and at regular intervals after commencing treatment with a DMARD. The cellular content of synovial membrane biopsies taken at regular intervals for a period of up to 3 yr after commencing treatment was quantitated by routine histopathology and immunohistochemical labelling with anti-macrophage (CD68) and anti-T lymphocyte (UCHL-1) antibodies. Synovial biopsies were quantitated with a validated semiquantitative scoring system and video image analysis. Results. Nine patients obtained clinical remission, as defined by American College of Rheumatology (ACR) criteria. The changes that occurred in the synovial biopsies included a reduction in lining layer thickness, reduced vascularity and cellular infiltrate. The most significant reduction in cellular infiltrate was in the lining layer macrophages, with less dramatic change in the subintimal macrophage infiltrate. Although there was a reduction in CD45 Ro-positive T lymphocytes in the synovial membranes of patients who attained ACR-defined disease remission, it was less significant than the reduction in macrophage content of the synovial membranes and tended to plateau at a reduced level of T-cell infiltration. Conclusions, Remission in RA patients is characterized by a predominant reduction in macrophage content of the synovial membrane, suggesting that current DMARDs may target this cell and its inflammatory mediators.

Ground Penetrating Radar (GPR) has been investigated as a non-destructive method for evaluating damage in concrete structures. However, the commercially available techniques are limited to detection of gross quantities of deterioration, due to the limited resolution of the system. The objective of this research is to evaluate a ground penetrating radar system with a novel Good Impedance Match Antenna (GIMA) for concrete structural assessment. This system has the capacity to detect concrete cracks as small as 1 mm thick, while being able to reflect from and detect features at depths of up to 360 mm. Laboratory results of testing of the GIMA antenna by using a step-frequency and a high-frequency impulse system are presented. The experimental results reveal that the GIMA antenna is capable for use in frequency ranges, at least as broad as 500 Mhz to 6 GHz for the step-frequency and 1 to 16 GHz for the high-frequency impulse system.

The neonatal immune system responds to a restricted range of antigens, producing largely IgM antibody of low affinity. Comparison of the components of the B-cell antigen receptor complex shows significantly elevated membrane levels of IgM in neonatal B cells, compared with adult cells. CD79, which acts as the signal transducer for membrane immunoglobulin, is elevated in parallel with IgM, while IgD is elevated to a lesser degree. CD19, CD21, CD22 and CD81, which are all involved in transmitting activation signals when immunoglobulin is engaged, are not elevated. CD32, which is involved in negative regulation of activation, is present at reduced levels on cord B cells. The elevation of B-cell membrane IgM persists during infancy. Neonatal B cells respond in vitro to interleukin-4 (IL-4) by further elevation of membrane IgM levels. The elevated level of membrane IgM may make neonatal B cells easier to trigger by low concentrations of antigen, but in vitro activation and immunoglobulin modulation experiments did not show significant differences between cord and adult B-cell responses to anti-IgM.

Gallium Nitride HEMT technology has reached the maturity where it is reliably being deployed for both military and commercial applications. But, because of its extreme ruggedness, reliable high temperature operation, and high operational RF power density, GaN based amplifiers can offer both new capability and challenges for Phased Array Systems. This work will present the basics of GaN technology, amplifier design methodologies and tradeoffs, and comparisons to traditional GaAs technology for use in phased array T/R modules.

This paper describes a millimeter-wave spread spectrum digital beamforming (MMW-SSDBF) technique employing large-aperture 2D MIMO virtual arrays. The MIMO array utilizes truly shift-orthogonal (TSOC) radar waveforms in order to significantly reduce hardware complexity, thereby enabling implementation of the low-cost wafer array. The architecture utilizes simple branch-line coupler bi-phase modulators per element to implement the beamforming operations, with a single digital transceiver for the whole array.

This paper reports on an X-band phased-array radar rooftop testbed at Applied Radar, Inc. The testbed was developed to support the integration of Applied Radar's digital receiver/exciter (DREX) hardware and open-systems architecture (OSA) back-end algorithms and real-time processing with a government-furnished active electronically steered array (AESA) antenna developed by Cobham Sensor Systems. We demonstrate the ground-moving-target-indication (GMTI) detection and tracking of vehicles and dismount targets in an open field from the rooftop-mounted antenna array sensor using pulse-Doppler processing. The demonstration system may be scaled up in the future to support air surveillance and include other array antennas and different frequency bands.

A highl y-sen sitile tlourescence method, capable of detecting cytokine receptors present at low concentrations (around I DO molecules per cell) by flow cytometry, was adapted for use on tissue sections. This method was used to examine the expression of several cytokine receptors in lymphoid ti ss ues. lL-2 receptors were distributed broadly, with higher concentrations in T cell areas. lL-1 receptor Type I was detected in T cell areas and in the follicular mantle, and was strongly expressed on vasc ular endothelium. IL-6 receptor was found at very low concentration, both within and outside germinal centres. The gp 130 molecule, which is involved in the functional receptor complex for IL-6 and several other cytokines, was present at higher concentrations, particularly in the germinal centre. Analysis of receptor expression in secondary lymphoid tissue provides evidence bearing on the physiological roles of cytokines, as these tissues contain cells at various stages of physiological activation located in well-defined functional zones.

Using a monoclonal antibody against the human p75 tumour necrosis factor receptor (TNFR-I) combined with a high-sensitivity immunofluorescence flow cytometric procedure, a proportion of peripheral blood lymphocytes can be shown to express TNFR-I constitutively. Approximately 50% of peripheral blood lymphocytes consisting mostly of CD4 cells and including most CD45R0-positive cells, express TNFR-I. Receptor expression is increased by a variety of activation signals. Only a minority (up to 30%) of tonsil B cells express measurable levels of TNFR-I. The tonsil B cells which express TNFR-I include both cells with a germinal centre cell phenotype and cells with the phenotype of the follicular mantle zone. Activation of B cells with anti-immunoglobulin, alone or in combination with interleukin-4 or interleukin-2, increases receptor expression, particularly in cells with the phenotype of mantle zone cells. The functional significance of constitutive expression of TNFR by blood and tissue lymphocytes is discussed.

The expression of the interleukin-4 receptor on human blood and tonsil lymphocytes has been studied using a monoclonal antibody and high-sensitivity immunofluorescence flow cytometry. While no receptor expression could be detected on circulating or tonsil T cells, a subset of B cells was shown to express the receptor. The IL-4R-positive B cells in tonsil had a phenotype suggesting that they included both germinal centre B cells and B cells outside the germinal centre. The subset of B cells in the blood that expressed the receptor included CD23-positive B cells. Activation of tonsil B cells using anti-IgM, IL-4, IL-2, or combinations of these reagents led to increases in IL-4R expression, but these changes were small compared to changes in the expression of IL-2R p55 (CD25), a known marker of activation. Similarly, activation of T cells led to low-level expression of IL-4R, with IL-4 itself up-regulating IL-4R, especially in CD4 cells. The majority of chronic lymphocytic leukaemia samples were positive for IL-4R expression, whilst most other leukemic samples were negative.

We have established and evaluated an organ fragment culture model for the study of human lymphocyte activation and differentiation.Small fragments of tonsillar tissue were cultured on Gelfoam for periods of up to 7 days.Monoclonal antibody in the medium was able to diffuse into the tissue, as demonstrated by subsequent detection of antibody-coated cells.Phytohaemagglutinin added to the culture medium caused activation of T and B cells, as indicated by changes in expression of a number of markers.Antibody against human IgM (added as a F(ab′) 2 fragment) together with IL-4 caused B cell activation, detectable by an increased expression of CD23 and other markers.Cell viability fell gradually in culture, but useful data could nevertheless be obtained from culture periods up to 7 days.The organ fragment culture provides a model for the study of T and B cell activation which maintains, at least in part, the intercellular interactions and the native microenvironment of lymphoid tissue.

This paper describes technology development efforts in support of phased-array digital beamforming at Applied Radar, Inc. The development efforts are aimed at increasing the bandwidth and dynamic range and enabling real-time throughput of multi-channel array data. This digital beamforming approach enables improved calibration, increased coverage through multiple receive beams, and adaptive processing and nulling. We describe enabling component technology including multi-channel FPGA-based digital hardware and a multi-channel wideband receiver. We also discuss a multi-channel wideband receiver system that was recently developed for electronic sensing and a wideband digital receiver/exciter (DREX) for radar applications

This paper presents a new type of circulator that consists of three Lange couplers and two ferrite circulators for broadband, high isolation, transmit noise suppression and simultaneous transmit and receive (STAR). The operation principal of the circulator is based on quadrature phase cancellation and combination techniques. Preliminary results show that the isolation between the transmit and receive port is >24 dB in frequency range of 5–12 GHz without optimization and 60 dB isolation with 800 MHz bandwidth with optimization. The NF data at the receive port show significant suppression of transmit noise for Gain-NF product that exceeds 21 dB.

Understanding of the pathophysiology of aortic valve stenosis (AVS) and finding potentially effective treatments are impeded by the lack of suitable AVS animal models. A previous study demonstrated the development of AVS in rabbits with vitamin D(2) and cholesterol supplementation without any hemodynamic changes in the cholesterol supplemented group alone. The current study aimed to determine whether AVS develops in an animal model with vitamin D(2) supplementation alone, and to explore pathophysiological mechanisms underlying this process. The effects of 8 weeks' treatment with vitamin D(2) alone (n=8) at 25,000 IU/4 days weekly on aortic valve structure and function were examined in male New Zealand white rabbits. Echocardiographic aortic valve backscatter (AV(BS)), transvalvular velocity, and transvalvular pressure gradient were utilized to quantitate changes in valve structure and function. Valvular histology/immunochemistry and function were examined after 8 weeks. Changes in valves were compared with those in endothelial function and in valvular measurement of thioredoxin-interacting protein (TXNIP), a marker/mediator of reactive oxygen species-induced oxidative stress. Vitamin D(2) treated rabbits developed AVS with increased AV(BS) (17.6+/-1.4 dB vs 6.7+/-0.8 dB, P

Background: Synovial biopsies are used to study synovial immunopathology and are increasingly applied for the evaluation of new therapeutic strategies in chronic arthritis. Therefore, it is essential to be informed on the complete spectrum of synovial immunopathology. Objective: To describe the cellular content, cytokine and cell adhesion molecule expression in synovial tissue from clinically and arthroscopically normal knees. Methods: Synovial tissue was obtained from 20 normal subjects at the time of knee joint arthroscopy for unexplained knee pain. Tissue sections were studied for basic histopathology and for a range of cell surface markers, cytokines, and cell adhesion molecules by immunoperoxidase staining. Stained sections were evaluated by semiquantitative scoring and digital image analysis. Results: Normal synovial tissue is composed predominantly of fibrofatty areolar tissue, with a variable thickness of intimal lining, composed of both CD68 positive macrophages and CD55 positive fibroblast-like synoviocytes. Interleukin 1 receptor antagonist (IL1Ra) was frequently detected in the synovial membrane of normal subjects (mean (SD) integrated optical density (IOD)=3809.6 (3893.9)), but both tumour necrosis factor alpha (TNFalpha) and interleukin 1beta (IL1beta) were rarely detected. In addition, cell adhesion molecules were rarely detected in the normal synovial membrane, with the exception of intercellular cell adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1). Osteoprotegerin (OPG) expression was abundant on synovial lining macrophages (mean (SD) IOD=5276 (4716) as well as endothelial cells (mean (SD) IOD=557 (226)), but receptor activator of nuclear factor kappa ligand (RANKL) expression was rarely seen. Conclusions: The normal synovial membrane has a variable architecture, including thickness of the lining and the subintimal cell infiltrate, with little inflammatory cytokine production or expression of cell adhesion molecules. The excess of OPG expression over RANKL and IL1Ra over IL1 may be important for protection against joint damage

Computed tomography (CT) with monochromatic X-ray beams was used to image phantoms and a live rabbit using the preclinical multiple energy computed tomography (MECT) system at the National Synchrotron Light Source. MECT has a horizontal fan beam with a subject apparatus rotating about a vertical axis. Images were obtained at 43 keV for single-energy studies, and at energies immediately below and above the 33.17 keV iodine K-edge for dual-energy subtraction CT. Two CdWO/sub 4/-photodiode array detectors were used. The high-resolution detector (0.5 mm pitch, uncollimated) provided 14 line pair/cm in-plane spatial resolution, with lower image noise than conventional CT. Images with the low-resolution detector (1.844-mm pitch, collimated to 0.922 mm detector elements) had a sensitivity for iodine of /spl ap/60 /spl mu/g/cc in 11-mm channels inside a 135 mm-diameter acrylic cylindrical phantom for a slice height of 2.5 mm and a surface dose of /spl ap/4 cGy. The image noise was /spl ap/1 Hounsfield Unit (HU); it was /spl ap/3 HU for the same phantom imaged with conventional CT at approximately the same dose, slice height, and spatial resolution (/spl ap/7 1p/cm). These results show the potential advantage of MECT, despite present technical limitations.

Objective. To investigate the change in synovial membrane cytokine content and cell adhesion molecule expression in sequential biopsies from the same knee joint of patients with rheumatoid arthritis, before and following anti-rheumatic drug treatment and to assess the relationship of these changes with clinical responses to the drug treatment. Methods. A selected group of patients with rheumatoid arthritis, some of whom had achieved a disease remission based on American College of Rheumatology (ACR) criteria, were included in this study. Sequential synovial biopsies obtained before and throughout the treatment period were studied by immunohistochemical labelling techniques for the cellular content, production of a range of pro- and anti-inflammatory cytokines and the expression of cell adhesion molecules. The staining was quantitated using computer-assisted digital image analysis. Results. There was a decrease in tumour necrosis factor-a (TNFa) and interleukin-1b (IL-1b) production in the synovial membrane lining and sublining of all patients who responded to treatment. The changes in IL-1 receptor antagonist production were variable. Paradoxically, there was a trend to decreased synovial membrane production of the anti-inflammatory cytokines, IL-10 and transforming growth factor-b (TGFb), while IL-4 was not detectable in any of the synovial membrane biopsies. A significant reduction in the density and total amount of E-selectin expression in the synovial membrane was seen. Similarly, intercellular adhesion molecule-1 (ICAM-1) expression in the lining and sublining was decreased in those patients who had a significant clinical response to drug treatment or attained disease remission. There were no consistent or significant changes seen in the expression of other cell adhesion molecules in the synovial membranes of these patients. Conclusions. Successful drug treatment of rheumatoid arthritis patients is characterized at the synovial membrane level by a decrease in TNFa, IL-10 and TGFb production. Some (E-selectin and ICAM-1) but not all (P-selectin, VCAM-1, PECAM-1) cell adhesion molecules are modulated in patients who respond clinically to drug treatment. E-selectin and ICAM-1 may be important targets for the development of future drug treatments for rheumatoid arthritis.

OBJECTIVE—Digital image analysis (DIA) offers the opportunity to quantify the stained area and staining intensity when synovial tissue (ST) is investigated by immunohistochemical analysis. This study aimed at determining the sensitivity of DIA compared with semiquantitative analysis (SQA). METHODS—Paired ST samples were obtained from the knee joint of 10 patients with rheumatoid arthritis (RA) with active disease and after follow up when complete clinical remission was achieved. ST samples of 10 subjects with non-inflammatory knee pain served as controls. Immunohistochemistry with antibodies against interleukin 1β (IL1β) and vascular cell adhesion molecule 1 (VCAM-1) was applied using two staining protocols with 3-amino-9-ethylcarbazole (AEC) or p-diethylaminobenzaldehyde (DAB) as dye. All sections were analysed semiquantitatively (0-4) and DIA of up to a maximum of 60 high power fields (HPF). The average integrated optical density was calculated as the product of the stained area (corrected for total tissue area) and the optical density. RESULTS—Both SQA and DIA enabled the assessment of differences in IL1β and VCAM-1 expression between ST from active RA, RA in remission, and controls. SQA and DIA showed excellent correlations (IL1β rs=0.867; p

Paired synovial tissue samples were obtained from both clinically uninvolved (CU) and clinically involved (CI) knee joints of eight rheumatoid arthritis (RA) patients. In addition, biopsies were taken from five control subjects. We observed the expression of the chemokines CXCL8, CXCL9, CXCL10, CCL2 and CCL4 in CI and CU joints of RA patients. In particular, CXCL8 protein levels were specifically increased in CI joints compared with CU joints, which was confirmed by immunohistochemistry and in situ hybridization.

Ground Penetrating Radar (GPR) can be an effective technique for assessing internal damage levels in concrete roadways. Damage to concrete roadways, particularly those on bridges, can have large economic consequences. Damage often takes the form of corrosion of reinforcing bars, the promotion of internal cracking, eventually large-scale spalling, and the formation of deep potholes. This damage usually initiates internally and does not appear on the surface until it is at an advanced state. The use of asphalt overlays further exacerbates this problem. One of the most important, yet difficult to identify, defects is a delamination, which can be due to expansion associated with reinforcing bar corrosion. The GPR reflections from a delamination can be relatively weak, whereas the reflection from a reinforcing bar can be fairly strong. Identifying the damage levels at an early stage can be used as a guide for efficiently planning maintenance activities. This paper presents the results of a laboratory and field study that focused on GPR methods of detecting delaminations in concrete roadways. The measurement technique used 0.5 to 6.0 GHz air-coupled waves to probe the roadways. Delaminations as small as 0.5 mm were simulated and detected in the laboratory. Field measurements are suggestive that this technique can be effective for field use.

Ground penetrating radar, often used for geophysics investigation and land mine detection, has been developed as a non-destructive means of concrete bridge health monitoring for nearly a decade. However, the commercially available systems are limited to estimating the location and gross quantities of the deterioration. The objective of this research is to develop a GPR system that can provide a more accurate method for obtaining detailed information, so that the location and magnitude of the delaminations and deterioration can be decided. A frequency band of 500 MHz to 6 GHz, was used for this system. A corresponding antenna with high resolution and radiation efficiency, Good Impedance Match Antenna, was developed for this frequency range. The system is able to distinguish features that are at least 360 mm deep in concrete. The GPR system, antenna, and experimental results from field investigations are presented.

DARPA sponsored a program during the fall of 1996 to collect backgrounds data (clutter and simulated targets) using several sensor systems. This paper focuses on the processing and interpretation of ground-penetrating (GPR) data collected using the Coleman ToMAS GPR system. High-resolution images generated using a backpropagation imaging (BPI) algorithm are presented for calibration lanes at two sites: one at Ft. A. P. Hill, VA, and the other at Ft. Carson, CO. Separate co- polarized and cross-polarized images are generated and compared. High-resolution cross-polarized images are also generated for an entire 100 meter X 100 meter 'center square' area at one site in 0.1 meter depth intervals. Comparison with Geonics EM-61 magnetometer as well as dig results are also presented.

The expression of CD95 antigen was examined on adult and cord blood lymphocytes using a highly sensitive immunofluorescence/flow cytometric procedure. CD95 was expressed by the majority of circulating blood T cells in adults, and by a smaller proportion of CD4+ and CD8+ T cells in cord blood. The majority of circulating B cells did not react with seven CD95 antibodies, but three antibodies did stain B cells. In tonsil sections, CD95 was expressed throughout the tissue, but germinal centres showed generally stronger staining than the surrounding follicular mantle and interfollicular areas. This was confirmed by flow cytometry, which showed expression preferentially on B cells with a germinal centre phenotype. Because different antibodies stained different proportions of B cells, CD95 epitopes were examined by inhibition, additive binding and protease susceptibility studies using a panel of ten CD95 antibodies. B cells apparently reacting selectively with CD95 antibodies were sorted and CD95 mRNA was reverse transcribed to cDNA and analyzed, in order to confirm the presence of CD95 in cells which reacted selectively and to explore the possible existence of CD95 isoforms. The major cDNA band was identical in the two populations. Inhibition of N-glycosylation suggested that the epitopes detected differentially could not be accounted for by differential N-glycosylation.

When cord blood is separated using standard methods based on Ficoll-Hypaque, the mononuclear fraction is contaminated with erythrocytes and also with nucleated cells that do not express the leucocyte marker CD45. The contamination with CD45-negative cells can exceed 50%, and will interfere with phenotypic, mRNA or functional analysis. A large proportion of these cells are erythrocyte precursors. The contaminating cells may be removed by lysis with hypotonic ammonium chloride; when the cells are required for studies which are adversely affected by ammonium chloride (such as antigen processing), high purity can be attained by two rounds of density separation.

The finite-difference time-domain (FDTD) algorithm, when modified to include dispersion, is a convenient tool for analyzing wave propagation in lossy, dispersive soils. It has been shown recently that a convenient way to include the dispersion is through a spatial array of digital permittivity or conductivity filters, one filter at each space node in the finite-difference grid. We address here the problem of selecting filter coefficients that result in accurate and stable FDTD implementations. We present a systematic procedure for determining the coefficients based on a nonlinear optimization procedure and stability test.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Human leucocytes from peripheral blood and tonsil were examined for the presence of the IL-3 receptor using monoclonal antibodies directed to epitopes of the alpha and beta chains of the receptor. We found that the beta chain, common to IL-3, IL-5, and GM-CSF, was either present at low levels or not detected on the majority of peripheral blood and tonsil B lymphocytes, while the alpha chain showed a distinct but restricted distribution. In peripheral blood the IL-3R alpha chain was limited to a subpopulation of peripheral B lymphocytes and a population of cells which lack lineage-specific markers. Dimly staining cells were identified as B lymphocytes as they coexpressed CD19, CD20, CD22, CD24, and HLA-DR. A brightly staining population lacks T and B lymphocyte, NK specific, and macrophage lineage markers but expresses CD9, CD45RO, CD26, and, in a proportion of cells, CD36 and CD60. This population remains unclassified. In tonsil tissue IL-3R alpha chain expression was strongest on B lymphocytes present in the T cell rich areas of tonsillar tissue. The IL-3R alpha bearing B tonsil cells included cells in both CD23 and IgD positive and negative populations. The phenotype of the IL-3R alpha positive B cells defines them as a population of B lymphocytes distinct from previously characterized cells in the lymphoid architecture. Lymphoblastoid cell lines with a corresponding phenotype were also identified.

FMC63 is an IgG2a mouse monoclonal antibody belonging to the CD19 cluster. CD19 antibodies react with a 95kDa protein expressed by cells of the B lymphocyte lineage, from pre-B cells to mature B lymphocytes. CD19 antibodies have been suggested as candidates for immunological attack on leukaemic and lymphoma cells of the B lineage because the antigen is restricted to the B lineage. With the potential use of FMC63 in immunotherapy in mind, we have produced a mouse-human chimera in which the genes coding for the VDJ region of the heavy chain and the VJ region of the light chain derive from the FMC63 mouse hybridoma, while the C region genes code for human IgG1. The genes have been transfected back into a mouse myeloma line, which secretes low levels of immunoglobulin. (Ig). This Ig was purified and biotinylated in order to determine the specificity of the antibody. The chimeric antibody has a reaction profile concordant with the original FMC63 antibody, but has the properties of a human IgG1, including the ability to fix human complement. However, the antibody is not cytotoxic in vitro in the presence of complement or cells capable of mediating antibody-dependent cellular cytotoxicity. Possible reasons for this and ways of using the antibody are discussed.

Whilst B cells in human blood can be shown to express interleukin-2 receptor (IL-2R) p55 and p75 chains, using a high-sensitivity immunofluorescence procedure, fresh tonsil B cells did not show detectable levels of expression. Culture of tonsil B cells led to low levels of expression of the p55 chain of the IL-2R, an effect which was dependent on protein synthesis. The level of expression of IL-2R chains could be modulated by culturing in the presence of a number of factors which activate B cells. p55 levels were more readily modulated than p75 levels. IL-4 and combinations of IL-4 with anti-IgM, IL-2 or tumour necrosis factor-beta (TNF-beta) modulated p55 levels, but IL-5 did not. Changes in IL-2R expression were small when compared with other B-cell activation markers such as CD23. When unfractionated tonsil cells were activated with a polyclonal stimulus, the major change was the expression of p55 by T-cell blasts--p75 expression remained low in T and B cells, and p55 expression by B cells remained low.