Laminin and vascular proliferation in rheumatoid arthritis

Laminin is a high molecular weight basement membrane structural glycoprotein. In rheumatoid arthritis and other arthropathies immunoreactive laminin was prominent in synovial blood vessel basement membranes and acted as a marker for them. It codistributed with collagen type IV. Immunohistological reactivity to laminin showed extensive vascular proliferation in rheumatoid arthritis together with basement membrane reduplication, which was confirmed ultrastructurally. Parallel histological studies showed vascular proliferation was predominantly in the subintimal rheumatoid synovium, where it was related to connective tissue proliferation but not to the inflammatory cell infiltrate. Vascular proliferation was also seen in relation to connective tissue changes in biopsies from cases of haemophilic arthritis, osteoarthritis, and meniscal tears. We suggest connective tissue activation is non-specific reaction associated with vascular proliferation. This involves laminin and other structural proteins. It occurs in rheumatoid arthritis and other arthropathies but is distinct from inflammatory cell infiltration.

Lymphocyte sub-populations and NSAIDs. Methodological aspects

Activated lymphocytes can be enumerated as the less dense lymphocyte population (LDL) on a Ficoll density gradient column. The numbers of LDL are higher in rheumatoid arthritis (RA) but fall with successful second-line therapy; they correlate with active synovitis rather than with extra-articular disease. A cytospin technique has been developed which uses fewer cells than conventional suspension techniques and which allows further characterization of LDL using monoclonal antibodies. This confirms that these cells are relatively T-depleted but enriched in IA bearing cells, which may relate to homing patterns to the RA synovium. Using this technique, RA patients with active synovitis were shown to have more LDL and IA bearing cells, as were the active disease controls, including patients with other autoimmune disease (vasculitis) and with non-immune disease (sepsis). There were no differences between the ratios of T-suppressor to T-helper cells within these patient groups.

Reticulin and its related structural connective tissue proteins in the rheumatoid synovium

Argyrophilic reticulin fibres are an important component of the rheumatoid synovium and their distribution and that of their individual protein constituents have been studied in synovial biopsies from a series of 29 cases of rheumatoid arthritis. In acutely inflamed synovia they are predominantly found underneath the hyperplastic synovial lining layer and related to the inflammatory cell infiltrate. With developing chronicity the reticulin network is gradually replaced by mature collagen. This histological pattern is mirrored by changes in the individual components of reticulin fibres-fibronectin, the non-collagenous reticulin component of Pras and Glynn (NCRC) and collagen type III.

The use of cytocentrifuge preparations for the demonstration of T cell surface antigens

Cytocentrifuged cell preparations have been evaluated as substrates for the demonstration by immunofluorescence of T cell surface antigens. Results obtained by a 2-stage method with fluorescent conjugate specific for the isotype of the first stage monoclonal antibody, and by a 3-stage procedure employing an intermediate antiserum to mouse IgG as amplifying agent, showed good correlation with those obtained by a standard technique performed on cells in suspension. These methods have the advantages of requiring fewer cells and less antibody and the cytocentrifuge preparations may be stored for batch assay.

The significance of IgM antinuclear antinuclear antibody in rheumatoid arthritis and other connective tissue diseases

An investigation of the incidence of IgG and IgM antinuclear antibodies (ANA) in patients with connective tissue diseases showed that IgM ANA predominated in rheumatoid arthritis, whilst in systemic lupus erythematosus IgG antibodies were more common. Patients with other connective tissue diseases less frequently had antinuclear antibodies and there was little difference in the incidence of IgG and IgM antibodies. Cross reacting rheumatoid factors contributed to the IgM antinuclear activity of rheumatoid sera. IgM ANA was not related to disease activity in patients with rheumatoid arthritis. Immunoglobulin class differences of ANA in rheumatoid arthritis and systemic lupus erythematosus may reflect the differing pathological processes of these two diseases and may be of value in their differential diagnosis.

Platelets in the synovial fluid of patients with rheumatoid arthritis

In a study of synovial fluid from 110 patients with various forms of arthritis, platelets were identified in the synovial fluid of all the 50 rheumatoids, in 18 out of the 25 (72%) with osteoarthritis and in all 35 of those with other forms of inflammatory osteoarthrosis. Identification of platelets by light microscopy was confirmed by electron microscopy. Platelet counts were significantly higher in rheumatoid fluid (mean 14 988/mm3; range 1000-65 000/mm3) compared with fluid from patients with osteoarthrosis (mean 1 592/Mm3; 0-10 000/mm3). In addition, significantly higher platelet counts were found in the synovial fluid (SF) of inflamed joints. There was a positive correlation between the SF platelet count and the total white cell count, polymorph count, hydrogen ion concentration, knee score, acid phosphatase and 5-nucleotidase activity and a negative correlation with the glucose level. All these factors indicate joint activity. Finally, platelet numbers correlated with SF levels of immunoglobulin M, and seropositive patients had significantly higher platelet counts in the SF compared with seronegative patients. Rheumatoid patients with thrombocytosis also had higher SF platelet counts. The close relationship of the SF platelet count to other indices of inflammation supports the concept that platelets may directly contribute to synovial inflammation by a variety of pathways.

Bovine milk N-acetyl-beta-D-glucosaminidase and its significance in the detection of abnormal udder secretions

A new spectrofluorimetric assay procedure for bovine milk N-acetyl-beta-D-glucosaminidase (NAGase) is described for use as a routine screening test for the detection of abnormal udder secretions. This procedure uses 4-methylumbelliferyl-N-acetyl-beta-D-glucosaminide as substrate. On the basis of the greater sample throughput, increased product sensitivity detection of NAGase and the absence of turbidity problems, it is considered to be superior to a previously reported spectrophotometric procedure (Kitchen, 1976). The correlation coefficient between the somatic cell count and the fluorimetric procedure using 243 quarter fore-milk samples was 0.86. Distribution studies on bovine milk and mammary gland homogenates indicated that this enzyme activity was located predominantly in the soluble whey protein fraction and the post-microsomal supernatant. Mammary gland secretory cells contained high levels of NAGase and appeared to be the major source of the enzyme in milk whilst NAGase from other sources (white blood cells, blood serum) contributed only a minor proportion (5-15%) of the total activity in milk. The implications of these findings on the value of the NAGase test as a means of mastitis diagnosis are discussed.

Conformational calculations of some azobilirubin isomers

A theoretical conformational analysis of one benzeneazodipyrromethene isomer of bilirubin in both the E and Z forms was performed by the PCILO method. The Z arrangement in its planar conformation showed the highest stability for this type of configurations.

Cerebral dysfunction and physical growth: the overgrown child

Images

Communal nursing in mice: influence of multiple mothers on the growth of the young

Female mice will combine their litters into a communal nest. The young raised in a communal nest show faster rates of growth during the first 20 days than young raised by single females, even when the ratio of mothers to young is the same.