Early rheumatoid arthritis is characterized by a distinct and transient synovial fluid cytokine profile of T cell and stromal cell origin

Pathological processes involved in the initiation of rheumatoid synovitis remain unclear. We undertook the present study to identify immune and stromal processes that are present soon after the clinical onset of rheumatoid arthritis ( RA) by assessing a panel of T cell, macrophage, and stromal cell related cytokines and chemokines in the synovial fluid of patients with early synovitis. Synovial fluid was aspirated from inflamed joints of patients with inflammatory arthritis of duration 3 months or less, whose outcomes were subsequently determined by follow up. For comparison, synovial fluid was aspirated from patients with acute crystal arthritis, established RA and osteoarthritis. Rheumatoid factor activity was blocked in the synovial fluid samples, and a panel of 23 cytokines and chemokines measured using a multiplex based system. Patients with early inflammatory arthritis who subsequently developed RA had a distinct but transient synovial fluid cytokine profile. The levels of a range of T cell, macrophage and stromal cell related cytokines ( e. g. IL-2, IL-4, IL-13, IL-17, IL-15, basic fibroblast growth factor and epidermal growth factor) were significantly elevated in these patients within 3 months after symptom onset, as compared with early arthritis patients who did not develop RA. In addition, this profile was no longer present in established RA. In contrast, patients with non-rheumatoid persistent synovitis exhibited elevated levels of interferon-gamma at initiation. Early synovitis destined to develop into RA is thus characterized by a distinct and transient synovial fluid cytokine profile. The cytokines present in the early rheumatoid lesion suggest that this response is likely to influence the microenvironment required for persistent RA

Do Nod-factor Levels Play a Role in Host-Specificity ?

Rhizobial Nod-factors are N-acylated oligomers of N-acetyl-D-glucosamine carrying a variety of substituents. At pico- to nano-molar concentrations, they provoke deformation and curling of nodulation competent root-hairs. Higher concentrations (10⁻⁷ to 10⁻⁶ M) elicit preinfection structures, allow Nod⁻ rhizobia to enter legume roots and to fix nitrogen within nodules. Evidence is accumulating that nodulation capacity is controlled both by specific Nod-factors as well as by Nod-factor concentrations. As an example, root-hairs of Macroptilium atropurpureum show identical "shepherd's crook" type curling when challenged with optimal (≈ 10⁻⁹ M) concentrations of Nod-factors of Bradyrhizobium japonicum and Rhizobium sp. NGR234 (which are Nod⁺) or with Nod-factors of R. leguminosarum and R. meliloti (both bacteria are incapable of nodulating Macroptilium). Similarly, conjugation of the nodD1 gene of NGR234 into R. meliloti allows nodulation of M. atropurpureum. We have used alkanisation of the tomato cell growth medium as a quantitative bioassay for Nod-factors. Upon induction with flavonoids, wild-type Rhizobium sp. NGR234 produces abundant Nod-factors, which may partly explain its extremely broad host-range. Nod-factors are produced throughout the log-phase of growth, while mutations in nodSU drastically reduce Nod-factor synthesis. Good correlations exist between the levels of Nod-factors and the ability to nodulate specific legumes

Involvement of <i>nodS</i> in <i>N</i>-Methylation and <i>nodU</i> in 6-<i>O</i>-Carbamoylation of <i>Rhizobium</i> sp. NGR234 Nod Factors

Although Rhizobium sp. NGR234 and Rhizobium fredii USDA257 share many traits, dysfunctional nodSU genes in the latter prohibit nodulation of Leucaena species. Accordingly, we used R. fredii transconjugants harboring the nodS and nodU genes of NGR234 to study their role in the structural modification of the lipo-oligosaccharide Nod factors. Differences between the Nod factors mainly concern the length of the oligomer (three to five glucosamine residues in USDA257 and five residues only in NGR234) and the presence of additional substituents in NGR234 (N-linked methyl, one or two carbamoyl groups on the non-reducing moiety, acetyl or sulfate groups on the fucose). R. fredii(nodS) transconjugants produce chitopentamer Nod factors with a N-linked methyl group on the glucosaminyl terminus. Introduction of nodU into USDA257 results in the formation of 6-O-carbamoylated factors. Co-transfer of nodSU directs N-methylation, mono-6-O-carbamoylation, and production of pentameric Nod factors. Mutation of nodU in NGR234 suppresses the formation of bis-carbamoylated species. Insertional mutagenesis of nodSU drastically decreases Nod factor production, but with the exception of sulfated factors (which are partially N-methylated and mono-carbamoylated), they are identical to those of the wild-type strain. Thus, Nod factor levels, their degree of oligomerization, and N-methylation are linked to the activity encoded by nodS

Broad-host-range <i>Rhizobium</i> species strain NGR234 secretes a family of carbamoylated, and fucosylated, nodulation signals that are <i>O</i>-acetylated or sulphated

Rhizobium species strain NGR234 is the most promiscuous known rhizobium. In addition to the non‐legume Parasponia andersonii, it nodulates at least 70 genera of legumes. Here we show that the nodulation genes of this bacterium determine the production of a large family of Nod‐factors which are N‐acylated chitin pentamers carrying a variety of substituents. The terminal non‐reducing glucosamine is N‐acylated with vaccenic or palmitic acids, is N‐methylated, and carries varying numbers of carbamoyl groups. The reducing N‐acetyl‐glucosamine residue is substituted on position 6 with 2‐O‐methyl‐L‐fucose which may be acetylated or sulphated or non‐substituted. All three internal residues are N‐acetylated. At pico‐ to nanomolar concentrations, these signal molecules exhibit biological activities on the tropical legumes Macroptilium and Vigna (Phaseoleae), as well as on both the temperate genera Medicago (Trifoliae) and Vicia (Viciae). These data strongly suggest that the uniquely broad host range of NGR234 is mediated by the synthesis of a family of varied sulphated and non‐sulphated lipo‐oligosaccharide signals

Differential expression of pyloric atresia in junctional epidermolysis bullosa with ITGB4 mutations suggests that pyloric atresia is due to factors other than the mutations and not predictive of a poor outcome: three novel mutations and a review of the literature

Junctional epidermolysis bullosa with pyloric atresia (JEB-PA) is an autosomal recessive blistering disease including lethal and non-lethal variants due to mutations in ITGB4 and ITGA6. It is unclear whether PA is caused directly by the mutations in these genes or by other factors. Skin biopsies from patients with JEB were processed for immunofluorescence mapping. When staining for integrin β4 or α6 was absent or reduced, ITGB4 was screened for mutations. A review of known mutations of ITGB4 and the phenotypes of patients with JEB-PA was undertaken. Three novel ITGB4 mutations were identified in 3 families with JEB-PA: 2 splice-site and one insertion mutation. Two families with lethal phenotypes (EB-050 and EB-049) were due to combinations of premature termination codons and missense mutations (658delC/R252C and 3903dupC/G273D, respectively). The third family EB-013 has 2 JEB affected siblings; a brother with PA and a sister without PA. Both were homozygous for ITGB4 264G>A/3111-1G>A. Two cases had no gastrointestinal symptoms or signs of PA. PA is an inconstant feature of the subtype of epidermolysis bullosa known as JEB-PA. It is most likely that multiple factors influence the development of PA and its presence is not predictive of a poor outcome. It is possible that institutions that do not routinely screen immunofluorescence mapping for integrin α6β4 staining in the absence of PA are missing this form of epidermolysis bullosa

<i>Rhizobium</i> species NGR234 host-specificity of nodulation locus III contains <i>nod-</i> and <i>fix-</i>genes

Most nodulatlon genes of the broad host-range Rhizobium sp. NGR234 are located on the 536 kb symbiotic plasmid. Complete sequencing of the replicon revealed over 400 open-reading frames (ORF), many of which correspond to known genes. Combined physical/genetic analysis of the host specificity of nodulation (hsn) locus lll revealed many nodulation genes, some of which are essential for Nod-factor production (nodABQ and others which modify the Nod-factor structure in specific ways (noeE). When mutated, two other genes, ORF3 and fixF gave Fix⁻ phenotypes on Vigna unguiculata. fixF has a nuclear localisation sequence (NLS) which is functional in nuclear targeting in tobacco protoplasts. Mutations in fixF abolish production of a novel, rhamnose-rich lipopolysaccharide that is produced under conditions of flavonoid induction

Adverse effects of topical corticosteroids in paediatric eczema: Australasian consensus statement

Atopic eczema is a chronic inflammatory disease affecting about 30% of Australian and New Zealand children. Severe eczema costs over AUD 6000/year per child in direct medical, hospital and treatment costs as well as time off work for caregivers and untold distress for the family unit. In addition, it has a negative impact on a child's sleep, education, development and self-esteem. The treatment of atopic eczema is complex and multifaceted but a core component of therapy is to manage the inflammation with topical corticosteroids (TCS). Despite this, TCS are often underutilised by many parents due to corticosteroid phobia and unfounded concerns about their adverse effects. This has led to extended and unnecessary exacerbations of eczema for children. Contrary to popular perceptions, (TCS) use in paediatric eczema does not cause atrophy, hypopigmentation, hypertrichosis, osteoporosis, purpura or telangiectasia when used appropriately as per guidelines. In rare cases, prolonged and excessive use of potent TCS has contributed to striae, short-term hypothalamic-pituitary-adrenal axis alteration and ophthalmological disease. TCS use can also exacerbate periorificial rosacea. TCS are very effective treatments for eczema. When they are used to treat active eczema and stopped once the active inflammation has resolved, adverse effects are minimal. TCS should be the cornerstone treatment of atopic eczema in children