The NLRP3 inflammasome pathway is activated in sarcoidosis and involved in granuloma formation

Sarcoidosis is a disease characterised by granuloma formation. There is an unmet need for new treatment strategies beyond corticosteroids. The NLRP3 inflammasome pathway is expressed in innate immune cells and senses danger signals to elicit inflammatory interleukin (IL)-1β; it has recently become a druggable target. This prompted us to test the role of the NLRP3 inflammasome and IL-1β pathway in granuloma formation and sarcoidosis.

19 sarcoid patients and 19 healthy volunteers were recruited into this pilot study. NLRP3 inflammasome activity was measured in bronchoalveolar lavage (BAL) cells and lung and skin biopsies using immunohistochemistry, Western blot, reverse-transcriptase PCR and ELISA. For in vivo experiments we used the trehalose 6,6′-dimycolate-granuloma mouse model and evaluated lung granuloma burden in miR-223 knockout and NLRP3 knockout mice, as well as the treatment effects of MCC950 and anti-IL-1β antibody therapy.

We found strong upregulation of the NLRP3 inflammasome pathway, evidenced by expression of activated NLRP3 inflammasome components, including cleaved caspase-1 and IL-1β in lung granuloma, and increased IL-1β release of BAL cells from sarcoid patients compared to healthy volunteers (p=0.006). mRNA levels of miR-223, a micro-RNA downregulating NLRP3, were decreased and NLRP3 mRNA correspondingly increased in alveolar macrophages from sarcoid patients (p<0.005). NLRP3 knockout mice showed decreased and miR-223 knockout mice increased granuloma formation compared to wild-type mice. Pharmacological interference using NLRP3 pathway inhibitor MCC950 or an anti-IL-1β antibody resulted in reduced granuloma formation (p<0.02).

In conclusion, our data provide evidence of upregulated inflammasome and IL-1β pathway activation in sarcoidosis and suggest both as valid therapeutic targets.

Depletion of activated macrophages with a folate receptor-beta-specific antibody improves symptoms in mouse models of rheumatoid arthritis

Objectives

Most therapies for autoimmune and inflammatory diseases either neutralize or suppress production of inflammatory cytokines produced by activated macrophages (e.g., TNFα, IL-1, IL-6, IL-17, GM-CSF). However, no approved therapies directly target this activated subset of macrophages.

Methods

First, we undertook to examine whether the folate receptor beta (FR-β) positive subpopulation of macrophages, which marks the inflammatory subset in animal models of rheumatoid arthritis, might constitute the prominent population of macrophages in inflamed lesions in humans. Next, we utilized anti-FR-β monoclonal antibodies capable of mediating antibody-dependent cell cytotoxicity (ADCC) to treat animal models of rheumatoid arthritis and peritonitis.

Results

Human tissue samples of rheumatoid arthritis, Crohn’s disease, ulcerative colitis, idiopathic pulmonary fibrosis, nonspecific interstitial pneumonia, chronic obstructive pulmonary disease, systemic lupus erythematosus, psoriasis, and scleroderma are all characterized by dramatic accumulation of macrophages that express FR-β, a protein not expressed on resting macrophages or any other healthy tissues. A monoclonal antibody to FR-β accumulates specifically in inflamed lesions of murine inflammatory disease models and successfully treats such models of rheumatoid arthritis and peritonitis. More importantly, elimination of FR-β-positive macrophages upon treatment with an anti-FR-β monoclonal antibody promotes the departure of other immune cells, including T cells, B cells, neutrophils, and dendritic cells from the inflamed lesions.

Conclusions

These data suggest that specific elimination of FR-β-expressing macrophages may constitute a highly specific therapy for multiple autoimmune and inflammatory diseases and that a recently developed human anti-human FR-β monoclonal antibody (m909) might contribute to suppression of this subpopulation of macrophages.

Electronic supplementary material

The online version of this article (10.1186/s13075-019-1912-0) contains supplementary material, which is available to authorized users.

Failing to fail: clinicians' experience of assessing underperforming dental students

INTRODUCTION

Anecdotal evidence within a UK dental school indicated that staff's grading did not always match their evaluation of students' clinical proficiency. The invalid assessment of underperforming students, which has considerable ramifications, has been reported internationally for students of nursing and medicine, but a database search revealed no accounts for dental education.

AIM

To develop an understanding of clinicians' approaches to assessing underperforming dental students.

METHODOLOGY

Seventeen clinical staff were interviewed (eleven females, six males). Interviews were recorded and transcribed verbatim. A grounded theory methodology was used, with simultaneous data collection and analysis. The main analytical technique was constant comparison.

FINDINGS

Participants' shared basic problem was Assessing undergraduate students, expressed as how they evaluated and used the assessment system or perceived others to do so. The core category, which explains what clinical staff do to manage their difficulties with assessment, was identified as Failing to Fail and has three subcategories: Evaluating the Assessment System, Shielding the Student and Protecting Myself.

CONCLUSION

This study has substantiated the complexity of failing to fail and confirmed that some causes are shared across healthcare professions, although insufficient staff discussion, the avoidance of confrontation and the impact of negative student attitude are not reported elsewhere or are minor findings. It is recommended that clinical staff receive additional training in assessment and that they are made more aware of their learning needs, their attitudes and beliefs. Increased discussion between staff about assessment and about students known to be in difficulty is essential.

The adenosine A1 receptor is a critical component in the modulation of cutaneous hypersensitivity by perceived stress (93.22)

Differential effects of acute and chronic stress on skin immunity occur in the rodent restraint stress model, with acute stress enhancing and chronic stress suppressing cutaneous hypersensitivity (CHS). Extracellular adenosine levels modulate diverse biological activities in the CNS and peripheral tissues and serve an important protective function against physiological stressors such as inflammation and ischemia. We used the restraint stress model and the skin sensitizing hapten DNFB to test if perceived stress influences CHS through an adenosine A1 receptor-mediated mechanism. We subjected hapten-sensitized A1 receptor knockout (A1KO) mice and their wild type (WT) littermates to either acute (2.5h) or chronic (5h daily x 4 weeks) restraint stress, or no stress (controls), followed by hapten re-challenge of the pinna. In WT mice, 48h pinna swelling augmented with acute stress (p = 0.008) and suppressed after chronic stress (p = 0.038). In contrast, CHS responses in the A1KO mice were not affected by acute or chronic stress. Absence of the adenosine A1 receptor did not affect levels of plasma corticosterone or urine catecholamines under these stressful conditions but was associated with elimination of stress-induced neutrophila otherwise observed in WT animals. These results suggest that the adenosine A1 receptor pathway plays a critical role in how perceived psychological stress influences CHS responses.

The anergic state in sarcoidosis is associated with diminished dendritic cell function

Sarcoidosis is a chronic inflammatory disease of unknown cause, characterized by granuloma formation similar to tuberculosis, but without clear evidence of a microbial infection. Because sarcoidosis is linked with clinical anergy and other evidence of diminished cellular immunity, we hypothesized that decreased skin delayed-type hypersensitivity (DTH) responses to recall Ags in affected individuals would be associated with decreased function of their blood dendritic cells (DCs). Our study involved ex vivo isolation, phenotyping, and functional testing of myeloid DCs (mDCs), plasmacytoid DCs, and T lymphocytes from blood of normal healthy volunteers and sarcoidosis subjects with active, untreated pulmonary disease. We found mDC function in the allogeneic MLR directly corresponded to the magnitude of skin DTH reactions to recall Ags in both sarcoidosis subjects and normal volunteers. However, both of these outcomes were significantly decreased in the sarcoidosis group. Diminished mDC function occurred despite up-regulated costimulatory and maturation markers. Clinical relevance is suggested by the inverse relationship between both mDC allogeneic responses and skin DTH responses with clinical disease severity as measured by chest radiograms. Because granulomas form when cellular immunity fails to clear antigenic stimuli, attenuated mDC function in sarcoidosis may contribute to susceptibility and persistence of the chronic inflammation characteristic of this disease.

Cardiac risk factors for dental procedures: knowledge among dental practitioners in Wales

OBJECTIVES

To determine knowledge and educational needs of dental practitioners in Wales regarding congenital or acquired cardiac disease and the provision of antibiotic prophylaxis.

DESIGN

Self-administered postal questionnaire.

SETTINGS

Cardiff University Dental Hospital, district general hospitals (HDS), all general dental practices (GDP) and community dental service (CDS) clinics throughout Wales. Methods A questionnaire sent to 1,182 dentists in Wales in 2004-5.

RESULTS

528 questionnaires were returned (a response rate of 45%). These were analysed using one-way analysis of variance to compare summary scores between the occupation groups. Significant differences in knowledge of cardiac risk factors for infective endocarditis and for dental procedures requiring cover were observed between the occupation groups. The majority of dentists (92% GDPs, 94% CDS and 77% HDS) requested postgraduate education in cardiac risk factors and laminated flow diagrams for their surgeries as the preferred educational format.

CONCLUSION

The knowledge of Welsh dentists regarding cardiac conditions or procedures which are risk factors for paediatric and adult patients varied according to place of work. The study identified potential for under- and over-prescription of antibiotic prophylaxis within the current guidance. There was confusion as to which patient groups and cardiac conditions required prophylaxis and for which particular dental procedures. Postgraduate education detailing advances in cardiology practice is necessary for dentists.

Vanadate, an inhibitor of stromelysin and collagenase expression, suppresses collagen induced arthritis

OBJECTIVE

Collagen induced arthritis (CIA) is a model of chronic inflammatory synovitis with pannus, neovascularization, and joint destruction similar to rheumatoid arthritis (RA). Matrix metalloproteinases (MMP) are involved in degradation of the extracellular matrix and joint destruction in RA. c-fos and c-jun are protooncogenes whose products combine to form activating protein (AP-1), a regulatory protein that is required for cell proliferation and the transcription of a variety of genes, including MMP such as collagenase and stromelysin. Administration of vanadium compounds suppresses c-fos/c-jun expression and AP-1 activity, resulting in inhibition of MMP expression in response to factors such as interleukin 1 (IL-1). We evaluated whether a vanadium AP-1 inhibitor could reduce MMP expression and subsequent joint damage in CIA.

METHODS

Vanadate [bis (maltolato) oxovanadium (IV) (BMOV; 10 mg/kg/day)] and the reducing agent N-acetyl cysteine (NAC; 100 mg/kg/day) were given subcutaneously daily in an attempt to suppress established CIA in rats. NAC in combination with vanadate appeared to increase the efficacy of c-fos/c-jun inhibition, while decreasing toxicity. Controls were given NAC alone. Clinical, radiographic, and histologic measures were evaluated as well as synovial MMP and IL-1a expression.

RESULTS

BMOV therapy, initiated on the day of onset of clinical arthritis, significantly reduced clinical arthritis within 2 days (p <0.05) compared to controls. Significance was maintained to the termination of the study on Day 18 post-arthritis onset (p < 0.005), with a maximum difference seen on Day 5 (p < 0.00001). Blinded radiographic scores at the completion of the protocols indicated less joint destruction in the experimental group compared to the control group (p < 0.005). Scanning and transmission electron microscopy confirmed the preservation of articular cartilage with therapy. In BMOV-treated rats, synovial mRNA expression of collagenase, stromelysin, and IL-la were reduced by 78%, 58%, and 85%, respectively, compared to controls.

CONCLUSION

This is the first study of vanadate as a potential antirheumatic agent. Further study of this AP-1 and MMP inhibitor may lead to new treatment options in RA.

Nonpulmonary manifestations of sarcoidosis

Sarcoidosis is one in a heterogeneous family of granulomatous disorders. The clinical manifestations of sarcoidosis can vary widely, depending on the patient and the tissues involved. Recent advances in our understanding of the immunologic steps leading to granuloma formation and persistence have yet to translate into more effective care for patients with this disease. This review discusses the immunology of granuloma formation and systemic disease, the various nonpulmonary expressions of the clinical disease, and the treatment options available to the practicing physician.

Thalidomide induces granuloma differentiation in sarcoid skin lesions associated with disease improvement

Sarcoidosis, a chronic granulomatous disease of unknown etiology, is treated with immune suppressive drugs such as corticosteroids. Sarcoidosis patients have been reported to benefit clinically from treatment with thalidomide. We administered thalidomide for 16 weeks to eight patients with chronic skin sarcoidosis and evaluated the drug's effects before and with treatment. After thalidomide treatment, all skin biopsies showed decreases in granuloma size and reduction in epidermal thickness. We also observed extensive T cell recruitment into the granulomas, the appearance of multinucleated giant cells, and increased numbers of dermal Langerhans cells (CD1a(+)) and mature dendritic cells (CD83(+) or DC-LAMP(+)). Plasma IL-12 levels increased and remained elevated during the treatment period. We noted increased HLA-DR expression on peripheral blood lymphocytes and a corresponding drop in the naive T cell marker CD45RA. Our data suggest that thalidomide treatment of sarcoidosis results in granuloma differentiation to a Th1-type cellular immune response usually associated with protective immunity to tuberculosis and tuberculoid leprosy.

The Th1/Th2 paradigm in the pathogenesis of scleroderma, and its modulation by thalidomide

The immunity generated in response to an antigenic stimulus can result in at least two distinct subclasses of immune responses, commonly referred to as Th1 and Th2. This review describes Th1- and Th2-type immune responses in animal models and in human mediated disease. Evidence obtained from working within these models suggests that manipulating the Th1/Th2 balance in the immune response can alter disease processes. The possible application of this strategy in scleroderma is presented. The immune modulating effects of the drug thalidomide on Th1 and Th2 immunity are also described, along with the drug's potential application to disease processes like scleroderma.

Suppression of recoil heating by an optical lattice

We report suppression of atomic heating by light scattering due to tight binding in a 3D far-off-resonant optical lattice. We show that rescattered spontaneously emitted photons do not heat trapped atoms when the scattering rate is much less than the trap vibrational frequency.

Immune stimulation in scleroderma patients treated with thalidomide

Scleroderma (SSc) is a fibrosing connective tissue disease that is poorly responsive to any treatment, including immune suppression. SSc shares many characteristics with chronic graft-versus-host disease (GVHD). Because the immunomodulatory drug thalidomide has proven beneficial in chronic GVHD, we studied the immune response and clinical effects of thalidomide in SSc patients. We treated 11 SSc patients with thalidomide in an open label, dose escalating, 12 week study. Histologic comparison of skin biopsies showed changes in skin fibrosis and an increase in epidermal and dermal infiltrating CD8(+) T cells with thalidomide treatment. In thalidomide-treated SSc patients, plasma levels of IL-12 and TNF-alpha increased, while plasma IL-5 and IL-10 levels remained unchanged. These changes were associated with clinical effects, including dry skin, dermal edema, transient rashes, decreased gastroesophageal reflux symptoms, and healing of digital ulcers. When SSc PBMCs activated by anti-CD3 mAb were exposed to thalidomide, increases in both production of IL-2, IL-3, GM-CSF, and IFN-gamma and T cell expression of CD40L were observed. Thalidomide therefore appears to induce immune stimulation in SSc patients in association with clinical changes. However, it remains to be shown whether long-term enhancement of immune responses in SSc patients is clinically beneficial.

Disruptive sexual selection for plumage coloration in a passerine bird

The theory of sexual selection was developed to explain the evolution of highly exaggerated sexual ornaments. Now supported by vast empirical evidence, sexual selection is generally considered to favour individuals with the most extreme trait expression. Here we describe disruptive selection on a sexual ornament, plumage coloration, in yearling male lazuli buntings (Passerina amoena). In habitats with limited good-quality nesting cover, the dullest and the brightest yearlings were more successful in obtaining high-quality territories, pairing with females and siring offspring, than yearlings with intermediate plumage. This pattern reflects the way that territorial adult males vary levels of aggression to influence the structure of their social neighbourhood. Adult males showed less aggression towards dull yearlings than intermediate and bright ones, permitting the dull yearlings to settle on good territories nearby. Fitness comparisons based on paternity analyses showed that both the adults and dull yearlings benefited genetically from this arrangement, revealing a rare example of sexually selected male-male cooperation.

Modulation of hyperoxia-induced TNF-alpha expression in the newborn rat lung by thalidomide and dexamethasone

The effect of high oxygen concentrations on lungs of neonatal rats was studied. In addition, some oxygen-exposed animals were treated with either dexamethasone or thalidomide. No gross histologic changes were noted in the lungs following exposure to 95% oxygen nor were there changes in the total number or the phenotypic distribution of BAL cells obtained from these lungs compared to lungs from air exposed (control) neonatal rats. The majority of the BAL cells were CD45+ leukocytes (macrophages). However, when BAL cells were exposed to LPS in vitro, TNF-alpha production was higher in cells from rats exposed to 95% oxygen compared to cells from rats exposed to ambient air. In addition, lung TNF-alpha and IL-6 mRNA levels were increased after exposure to 95% oxygen. In the lungs of animals treated with either dexamethasone or thalidomide, TNF-alpha mRNA levels were reduced, while only dexamethasone treatment also reduced IL-6 mRNA levels.

Thalidomide analogue CC1069 inhibits development of rat adjuvant arthritis

The cytokine tumour necrosis factor-alpha (TNF-alpha) has been implicated in the aetiology of rheumatoid arthritis in humans as well as of experimental arthritis in rodents. Thalidomide, and to a greater extent the new thalidomide analogue CC1069, inhibit monocyte TNF-alpha production both in vitro and in vivo. The aim of the present study is to establish whether these drugs block production of TNF-alpha as well as IL-2 by rat leucocytes and whether this inhibition affects the development of rat adjuvant arthritis (AA). Cultured splenocytes were stimulated with either lipopolysaccharide (LPS) or concanavalin A (Con A) in the presence of thalidomide, CC1069, or solvent, and the production of TNF-alpha and IL-2 were compared. Next, adjuvant was injected into the base of the tail of rats without or with daily intraperitoneal injections with 100-200 mg/kg per day thalidomide or 50-200 mg/kg per day CC1069. Disease activity, including ankle swelling, hind limb radiographic and histological changes, weight gain, and ankle joint cytokine mRNA levels, were monitored. CC1069, but not the parent drug thalidomide, inhibited in vitro production of TNF-alpha and IL-2 by stimulated splenocytes in a dose-dependent manner. In vivo, a dose-dependent suppression of AA disease activity occurred in the CC1069-treated animals. In contrast, thalidomide-treated rats experienced comparable arthritis severity to placebo-treated animals. There was also a reduction in TNF-alpha and IL-2 mRNA levels in the ankle joints of CC1069-treated rats compared with thalidomide- and placebo-treated arthritic rats. Early initiation of CC1069 treatment suppressed AA inflammation more efficiently than delayed treatment. We conclude that thalidomide, which did not suppress TNF-alpha or IL-2 production in vitro by Lewis rat cells, did not suppress development of rat AA. However, the development of rat AA can be blocked by the thalidomide analogue CC1069, which is an efficient inhibitor of TNF-alpha production and IL-2 in vitro.

The effect of thalidomide and 2 analogs on collagen induced arthritis

OBJECTIVE

Thalidomide has been described as an inhibitor of both angiogenesis (which may account for its teratogenic effects on limb bud formation) and tumor necrosis factor-alpha (TNF-alpha) production. We evaluated its therapeutic potential in collagen induced arthritis (CIA), a rat model of rheumatoid arthritis (RA).

METHODS

Rats were administered orally 200 mg/kg/day thalidomide (n = 10) or either of 2 analogs, EM-12 (n = 9) or supidimide (n = 9). An additional group was given thalidomide (n = 10) at 200 mg/kg twice daily, and a control group (n = 13) was given vehicle only. At completion of the protocols, serum levels of TNF-alpha and vascular endothelial growth factor (VEGF) were measured.

RESULTS

Suppression of inflammatory synovitis by clinical and radiographic criteria was significantly lower in all experimental protocols except the lower dose thalidomide group. The EM-12 analog was the most efficacious, and twice daily thalidomide was better than once daily. The incidence of arthritis onset was comparable among all groups. Strong cell mediated and humoral responses to type II collagen, measured by a radiometric delayed type hypersensitivity assay and anti-type II collagen IgG ELISA, respectively, were similar in the experimental and control groups. TNF-alpha and VEGF levels were increased in all rats immunized with collagen compared to naive controls.

CONCLUSION

Thalidomide and its analogs can suppress the clinical severity of rat CIA, but the mechanism of action is not a result of TNF-alpha or VEGF downregulation.

Combination therapy in rheumatoid arthritis: the animal model perspective

Attempts to improve antirheumatic agent efficacy have resulted in exploration of treatment protocols with combinations of 2 or more agents. Hypothetically, an ideal combination therapy would have greater efficacy and less toxicity than any of its component agents used individually. However, even a limited number of available drugs can produce a daunting number of possible combination protocols, each requiring clinical evaluation. Intelligent selection of combination protocols, based on a firm understanding of each agent's specific mechanism(s) of action, may help identify potentially useful regimens. Autoimmune animal models of inflammatory synovitis provide a unique opportunity to study the etiology, pathophysiology, and treatment of rheumatoid arthritis (RA). Induction of chronic inflammatory synovitis in susceptible inbred strains can allow for in vivo study under reproducible controlled conditions, using experimental protocols not possible in humans. Although animal models can only approximate human rheumatic disease in its complete form, they are nonetheless important for developing new therapeutic strategies. We review the 3 most common animal models of RA, the streptococcal cell wall, adjuvant, and collagen arthritis rat models. Surprisingly, few published studies evaluate combination therapy in RA animal models. We discuss these investigations, which use interventions aimed at angiogenesis, microtubule function, and immune regulation, as examples of animal models to assess and develop effective therapeutic combinations of antirheumatic agents.

Suppression of collagen-induced arthritis by an angiogenesis inhibitor, AGM-1470, in combination with cyclosporin: reduction of vascular endothelial growth factor (VEGF)

Pannus formation characterized by neovascularization is a prominent pathologic finding in both rheumatoid arthritis (RA) and rat collagen-induced arthritis (CIA). CIA is a T-cell-dependent process induced by immunization of inbred LOU rats with native type II collagen in incomplete Freund's adjuvant. AGM-1470 is a highly specific inhibitor of new blood vessel formation by its effects on endothelial cell migration, endothelial cell proliferation, and capillary tube formation. Cyclosporin A (CSA) is an immunomodulating agent that inhibits IL-2 and other cytokine production involved in early antigen activation of T-cells. In this study the effects of single and combination therapy with AGM-1470 (27 mg/kg alternate days) and low-dose CSA (4 mg/kg/day continuous infusion via osmotic pump) on established CIA (total n = 62) were examined. At Day 18 post arthritis onset, clinical arthritis was significantly reduced in rats treated with single-agent AGM-1470 (1.88 +/- 0.33) or combination therapy (1.13 +/- 0.32) (P < 0.00001 and 0.000001, respectively) versus control. Single-agent CSA-treated rats, even if given CSA beginning on the day of immunization, did not attenuate arthritis severity. THe longitudinal mean arthritis score of combination-treated rats was significantly lower than that of rats receiving AGM-1470 (P < 0.0001), reflecting a more moderate early disease course in combination-treated rats. Disease severity in rats treated with single-agent CSA was not significantly different from control rats. Mean WBC counts, differentials, and delayed-type hypersensitivity responses were similar in all groups. CII antibody levels were lower in AGM-1470 protocols compared to CSA or controls. Flow cytometry of peripheral blood, spleen, and lymph nodes demonstrated decreased levels of CD4+ cells in rats given CSA. TNF-alpha levels remained elevated, even in treated rats, while vascular endothelial growth factor levels were reduced in rats receiving AGM-1470 compared to both arthritic controls and naive rats. Both single-agent and combination therapies were well tolerated. This is the first study to examine the effects of AGM-1470 together with CSA. Combination therapy was more effective than single-agent therapy. The results suggest that the use of interventions with distinct mechanisms of action may be efficacious in the treatment of RA.

Suppression of collagen-induced arthritis using an angiogenesis inhibitor, AGM-1470, and a microtubule stabilizer, taxol

Collagen-induced arthritis (CIA) is a T-cell-dependent rat model of rheumatoid arthritis (RA) that is induced by injection of collagen type II in incomplete Freund's adjuvant. Neovascularization within the synovium is a prominent feature of CIA and RA. The novel angiogenesis inhibitor AGM-1470 and the microtubule-stabilizing agent Taxol represent two new classes of agents with specific mechanisms of action. AGM-1470 inhibits fibroblast growth factor-induced stimulation of endothelial cell migration, endothelial cell proliferation, and capillary tube formation, resulting in effective suppression of new blood vessel formation. By enhancing microtubule polymerization, Taxol interferes with normal microtubule function in cell mitosis, migration, chemotaxis, and intracellular transport. Using a suppression protocol in established CIA, the effects of AGM-1470 and Taxol as single agents and in combination were evaluated. Combination therapy significantly reduced clinical arthritis compared to control rats (P < 0.00001). The combination therapy group also experienced earlier and significantly greater reduction of clinical arthritis compared to either single agent-treated groups (P < 0.05). Blinded radiographic scores at the end of the study demonstrated less soft tissue swelling and joint destruction using combination therapy than either single agent. This is the first use of AGM-1470 and Taxol in combination therapy. Further study of agents with distinct mechanisms of action may lead to more effective treatment options in chronic inflammatory arthritis and to a better understanding of the pathophysiologic processes of pannus formation.

Loss of the first permanent molar and caries experience of adjacent teeth

The caries experience of the occlusal and distal surfaces of the second premolars and the occlusal and mesial surfaces of the second permanent molars was examined in four groups of subjects aged 19-20 years. Group 1 comprised subjects with first permanent molars present, Group 2 subjects with early loss of the first permanent molar (before the age of 11-12 years), Group 3 subjects with late loss of the first permanent molar (after 11-12 years but before 15-16 years) and Group 4 included a combination of Group 2 and Group 3. Loss of the first permanent molar was associated with increased caries or restorations in the occlusal surfaces of adjacent teeth, but reduced caries or restorations in the proximal surfaces of adjacent teeth. Early loss of the first molar was associated with significantly greater caries or restoration experience in proximal surfaces than late loss, but no difference was detected for occlusal surfaces.

Factors influencing the initiation of carious lesions in specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years

An analysis of factors influencing the initiation of carious lesions on specific tooth surfaces over a 4-year period in children between the ages of 11-12 years and 15-16 years is presented. Approximately 1000 children, resident in the County of South Glamorgan, Wales, were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. On both occasions, the children completed detailed questionnaires on dental health-related topics. Surfaces which were sound when the children were 11-12 years were identified and subsequently awarded a score of zero if they remained sound at 15-16 years or a score of one if they had developed carious lesions or had been filled. For each child, a mean mouth caries initiation score was computed for specific groups of surfaces, namely pit and fissure surfaces in posterior teeth, approximal surfaces in posterior teeth, buccal and lingual smooth surfaces of all teeth and approximal surfaces of anterior teeth. One-way analysis of variance and multiple regression techniques revealed that a number of factors had a significant influence on the initiation of caries. The factors and their level of significance varied between the surfaces. However, relatively little (less than 6 per cent) of the total variance in caries initiation score could be explained by the identified factors. Overall, more lesions developed in pit and fissure surfaces in posterior teeth than in the other surfaces included in the analyses.

Factors influencing the caries experience of a group of children at the ages of 11-12 and 15-16 years: results from an ongoing epidemiological survey

An analysis of factors influencing the caries experience of adolescents in South Wales is presented. Approximately 1000 children were assessed for caries status and oral cleanliness in 1980 when aged 11-12 years and again in 1984 when aged 15-16 years. In addition, on both occasions, the children completed detailed questionnaires on dental health-related topics. When aged 11-12 years, the observed mean DMFT, DMFS and DFS scores of the children were 4.0, 6.7 and 5.5 respectively. The corresponding scores at age 15-16 years were 6.5, 11.8 and 10.2. A preliminary analysis using conventional multiple regression techniques revealed that a number of factors had a significant influence on the caries experience of the children. The significance of the factors depended on the sex of the population subgroup, the age of the children and the particular caries index studied. However, at both ages the factors of most significance were the number of erupted teeth, total mean plaque score and the reported amount of money spent on sweets per week. A further evaluation using analysis of covariance with the number of erupted teeth and surfaces as the covariates confirmed the significant influence of the total mean plaque score and amount of money spent on sweets. In addition, both analyses indicated that toothbrushing frequency and social class had a significant influence on the caries experience of boys.