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Biomedical subjects

L Schrieber

Publications and source records attributed to L Schrieber.

At least 37 records · Page 2Linked to original sources
PubMed1990

Correlation between tests of muscle involvement and clinical muscle weakness in polymyositis and dermatomyositis.

A correlation study was performed on the degree of muscle weakness in 36 patients with dermatomyositis and 69 with polymyositis in relation to muscle biopsy findings, electromyography (EMG) abnormalities, and serum concentrations of creatine kinase (CK), aspartate aminotransferase (AST) and alanine aminotransferase (ALT) enzymes. Statistically significant correlations were found between muscle weakness and EMG results in patients with polymyositis, and between muscle weakness and serum CK and AST levels in dermatomyositis. As expected, correlations were found between the results of the three enzyme determinations in both groups of patients.

Alanine Transaminase↗
PubMed1990

Antiphospholipid antibodies in systemic lupus erythematosus: clinical and laboratory associations in 111 patients.

An enzyme linked immunosorbent assay (ELISA) was used to evaluate the prevalence and disease associations of antibodies to a range of negatively charged phospholipids in 111 patients with systemic lupus erythematosus (SLE). The frequency of one or more isotypes of different antiphospholipid antibodies (APLs) was similar (range 33%-45%). When individual isotypes were considered alone there was considerable variation (range 5%-32%). There were significant associations between thrombosis, thrombocytopenia, and central nervous system (CNS) disease but not abortion with elevated APL. Strong associations were found between raised anti-ds-DNA (Farr assay) and a positive direct Coomb's test with raised APL. Thus, APLs are common in SLE and are associated with discrete clinical and laboratory features. However, detection of antibodies to a range of negatively charged phospholipids added little clinically useful information to that obtained by measuring anticardiolipin antibody (ACL) alone. We cannot recommend the use of APLs other than ACL for routine testing.

Adolescent↗
PubMed1990

A case-control study of congenital heart block: association with maternal antibodies to Ro(SS-A) and La(SS-B).

A case control study of congenital complete heart block (CHB) was undertaken to determine the degree of association of this condition with maternal connective tissue disease and with maternal autoantibodies, in particular those to Ro(SS-A). Mothers of cases (n = 18) and controls (n = 72) completed a self-administered questionnaire and donated 10 ml of blood. The odds of giving birth to a child with CHB were increased by a factor of 22 for women with antibodies to Ro(SS-A) and/or La(SS-B) compared with women who did not have these antibodies. Thus the association between CHB and both anti-Ro(SS-A) and anti-La(SS-B) antibodies has been demonstrated in an Australian population and indicates that anti-La(SS-B), as well as anti-Ro(SS-A) antibodies may be a risk factor for the development of CHB.

Adolescent↗
PubMed1990

The cycling of combination antirheumatic drug therapy in rheumatoid arthritis.

In this open pilot study a combination of hydroxychloroquine, prednisolone and alternating months of treatment with sulphasalazine or oral weekly pulse methotrexate has been investigated in 16 patients with rheumatoid arthritis (RA) refractory to a total of 67 disease suppressive medications. Results at 3 months indicated significant improvements in visual analogue score for pain, joint count, Ritchie index, scale of disability related to activities of daily living, ESR, rheumatoid factor and C-reactive protein. This degree of improvement, however, was not maintained 6 and 12 months after commencement of treatment. Pain score, Ritchie index and ESR were the only parameters demonstrating significant improvement at 12 months. Therapy was terminated in eight patients, half due to lack of efficacy and half because of side effects.

Activities of Daily Living↗
PubMed1990

Effect of leukotriene B4 and prostaglandin E2 on the adhesion of lymphocytes to endothelial cells.

The arachidonic acid metabolites leukotriene B4 (LTB4) and prostaglandin E2 (PGE2) may play an important role in inflammation. It is not known whether these mediators influence the binding of lymphocytes to endothelial cells, a process which is important in the extravasation of lymphocytes in inflammatory states. In the present investigation, the effect of LTB4 and PGE2 on the binding interaction between lymphocytes and endothelial cells was examined using a centrifugation cell binding assay. Although LTB4 elicited an aggregation response on human polymorphonuclear leucocytes (PMNL) and enhanced their binding to endothelial cells it had no effect on lymphocyte binding. By contrast, PGE2 caused a dose-dependent inhibition of lymphocyte binding to endothelial cells. The inhibitory effect of PGE2 had a rapid onset but was exhibited only when PGE2 was present continuously during the cell binding assay. Although the mechanism by which PGE2 acts is not clear, it may provide a negative feedback mechanism in regulating the influx of lymphocytes into inflammatory sites.

Cell Adhesion↗
PubMed1990

Binding of human endothelium to Ulex europaeus I-coated Dynabeads: application to the isolation of microvascular endothelium.

A major problem encountered when isolating human microvascular endothelium is the presence of contaminating cells such as fibroblasts that rapidly over-grow the endothelial cells. We describe here a simple, rapid technique for purifying endothelial cells derived from the microvasculature of neonatal foreskin and osteoarthritic and rheumatoid arthritic synovium. This technique is based on the selective binding of the lectin Ulex europaeus I (UEA I) to the endothelial cell surface via fucose residues. Initially UEA I was covalently bound to tosyl-activated super-paramagnetic polystyrene beads (Dynabeads) by incubation for 24 h at room temperature. Cells were isolated by extracting microvascular segments from enzyme-treated (trypsin and Pronase) cubes of tissue. The mixed population of cells obtained were purified by incubating them at 4 degrees C for 10 min with the UEA I-coated Dynabeads. Endothelium bound to the beads whilst contaminating cells were removed by five washes with HBSS using a magnetic particle concentrator. The endothelial cells thus obtained grew to confluence as a cobblestone-like monolayer and expressed von Willebrand factor antigen. The cells were released from the Dynabeads by the competitive binding of fucose (10 min at 4 degrees C). This new method is simple and reproducible and allows pure human microvascular endothelial cells to be cultured within 2 h of obtaining a specimen.

Cell Line↗
PubMed1990

Aberrant lymphocyte migration patterns in systemic lupus erythematosus (MRL/l, MRL/n) mice are independent of the micro-environment.

Mice with systemic lupus erythematosus (SLE) have unusual patterns of lymphocyte traffic characterised by diminished uptake of intravenously injected autoimmune cells into lymph nodes. This study examines the influence of the lymphocyte micro-environment on this aberrant migratory behaviour. To evaluate lymph node lymphocyte-endothelial interactions which can affect lymphocyte distribution without the in vivo influence of liver and spleen, the in vitro high endothelial venule (HEV) binding assay was used. Lymph node HEV binding of autoimmune MRL-lpr/lpr (MRL/l) and MRL(-)+/+ (MRL/n) lymphocytes was increased when compared with CBA/T6 lymphocytes and contrasted with diminished lymph node uptake noted in vivo. This was independent of the lymph node source (MRL/l, MRL/n, CBA/T6) onto which the lymphocytes were overlaid. To examine the influence of the microenvironment on in vivo traffic, 21Cr-labelled lymph node cells from normal CBA/T6 mice were injected into sex-matched MRL/l, MRL/n and CBA/T6 recipients. The distribution of cells was the same in each recipient strain suggesting that the micro-environment had little influence on the lymphocyte trafficking profiles of autoimmune mice. This study supports the view that aberrant lymphocyte migration in autoimmune mice results from defects intrinsic to the lymphocyte population and not the micro-environment.

Age Factors↗
PubMed1989

Rheumatic manifestations of neoplasia.

The important association of neoplasia and rheumatic disease was reviewed. The literature in the last year included case reports of neoplasia, particularly hematologic, causing arthritis by direct joint involvement. Immunocytologic techniques may help in the diagnosis. The evidence linking dermatomyositis and polymyositis to malignancy was reviewed, although analysis of the literature was hampered by poor documentation and lack of control subjects. HOA may occur secondary to mediastinal or pulmonary metastases from nonbronchogenic malignancies. The important association of hematologic malignancy with vasculitis was highlighted.

Arthritis↗
PubMed1989

Isolation and propagation of endothelial cells derived from rheumatoid synovial microvasculature.

Synovial angiogenesis may play an important part in the destruction of articular cartilage in patients with rheumatoid arthritis (RA). As an important first step towards developing in vitro models of synovial angiogenesis, microvascular endothelial cells have been isolated, purified, and cultured from operative synovial specimens obtained from adult patients with RA.

Arthritis, Rheumatoid↗
PubMed1989

Lymphocyte migration patterns in autoimmune MRL-lpr/lpr mice: relationship to age, disease manifestations and lymphocyte homing receptor expression.

We have previously reported that lymphoid cells from systemic lupus erythematosus (SLE) mice with established disease migrate aberrantly. This study evaluates the abnormal lymphocyte migration patterns found in MRL-lpr/lpr (MRL/l) mice in relation to age, disease manifestations and the expression of lymphocyte homing receptors. 51chromium-labelled lymph node cells from MRL/l and from normal histocompatible CBA mice of different ages were injected i.v. into age and sex-matched CBA recipients. Diminished lymph node and increased hepatic uptake of MRL/l compared to CBA cells was evident as early as 6 weeks of age. Abnormalities in lymphocyte migration antedated the appearance of elevated antihistone antibody (AHA) levels but not the development of lymphadenopathy. Using the monoclonal antibody MEL-14, no differences in the expression of lymphocyte homing receptors between MRL/l and CBA lymph node cells were found at any age. Thus abnormalities in lymphocyte migration in MRL/l mice appear as early as six weeks and are not related to changes in homing receptor expression.

Age Factors↗
PubMed1989

Enhanced interferon-gamma (IFN) production by lymph node cells from autoimmune (MRL/1, MRL/n) mice.

Interferons (IFNs) have been implicated in the aetiopathogenesis of the autoimmune disease systemic lupus erythematosus (SLE). The ability of unstimulated and Sepharose-bound concanavalin A (ConA) stimulated spleen or lymph node (LN) cells from normal CBA/T6 mice and histocompatible autoimmune strains (MRL/1, MRL/n) of various ages to produce IFN-gamma was measured. Levels of IFN-gamma produced by ConA-stimulated spleen cells from CBA/T6, MRL/1 and MRL/n mice at 6 weeks of age were not statistically different (mean +/- SEM: 786 +/- 182, 1147 +/- 282, 1024 +/- 146 IU/ml, respectively). At this age only stimulated LN cells from MRL/l mice produced detectable IFN-gamma (538 +/- 44 IU/ml) and these levels remained constant up to 6 months. IFN production by stimulated LN cells from young MRL/n mice (66 +/- 21 IU/ml at 3 months, 44 +/- 41 IU/ml at 6 months) increased at 1 year (463 +/- 97 IU/ml) corresponding to the age of disease onset. The failure of stimulated CBA/T6 LN cells to produce IFN-gamma was not due to cell-cell suppression, defective IL-2 production or the generation of soluble inhibitors. Stimulated LN cells from other normal inbred (C57Bl/6, Balb/c, A/J) outbred and FI hybrid mouse strains (Swiss, [Swiss x Balb/c] F1, (CBA/T65 x C57Bl/6]FI) produced undetectable or low levels of IFN compared to MRL/1 and MRL/n mice. These results show that autoimmune mouse LNs generate more IFN compared to normal controls and that the increase in IFN levels (at least in MRL/n) corresponds to the age of disease onset.

Animals↗
PubMed1988

Immunomodulators.

A new era is emerging in the therapy of rheumatic disease involving the use of biologically based immunomodulators. Cytokines, such as the interleukins and interferons, are proteins produced by activated lymphoid cells which can now be synthesised by genetic engineering techniques. These agents have already been used to correct "immune deficiencies" in patients with neoplastic and inflammatory disease e.g. gamma-interferon in rheumatoid arthritis (RA). Monoclonal antibodies (mca) targeted against lymphocyte cell surface receptors or against autoantibodies have been successfully applied in human lymphoid malignancies, organ transplantation and in animal models of arthritis. Potential problems in man include the development of allergic reactions to mouse proteins and of antibody resistance. Although in its infancy, immunomodulation represents an exciting approach to the treatment of rheumatic disease.

Adjuvants, Immunologic↗
PubMed1988

Splenic and renal infarction in systemic lupus erythematosus: association with anti-cardiolipin antibodies.

A 37-year-old female, known to have systemic lupus erythematosus (SLE) and markedly raised anti-cardiolipin antibody levels in association with the lupus anticoagulant, presented with a symptomatic segmental splenic infarction. There was a past history of cerebral infarction. Abdominal computed tomography (CT) demonstrated the area of splenic infarction, and an asymptomatic right renal infarct. This patient illustrates the unusual occurrence of multiple visceral infarcts, in association with anti-cardiolipin antibodies, complicating SLE.

Adult↗
PubMed1988

High endothelial venule morphology and function are inducible in germ-free mice: a possible role for interferon-gamma.

Cytokines may facilitate lymphocyte traffic by modulating HEV structure and lymphocyte binding function in accordance with local tissue requirements. This study investigated whether the morphology of HEVs and their lymphocyte binding ligand are altered following antigenic challenge and evaluated the role of IFN-gamma in the induction of such changes. The morphology and lymphocyte binding function of mesenteric LN HEVs of GFM exposed to environmental pathogens were compared to those from GFM and conventional mice. Lymph nodes from all mice had microscopically identifiable HEVs. The morphology of HEVs from GFM was not uniform; many HEVs contained flat endothelial cells with sparse cytoplasm and prominent interendothelial gaps. The number of lymphocytes within the lumen and the HEV wall was low. In contrast, HEVs from GFME and conventional mice were characterized by cuboidal endothelial cells with plentiful cytoplasm and large numbers of lymphocytes in the vessel wall and lumen. There was no delineation of interendothelial cell borders. Lymphocyte binding to HEVs of lymph node sections from GFM was reduced (mean +/- SEM: 1.08 +/- 0.15) compared to that of conventional mice (1.91 +/- 0.20), P less than 0.003. GFME had augmented lymphocyte binding (2.23 +/- 0.26) to levels comparable with those of conventional mice. GFM injected intraperitoneally with IFN-gamma, IFN-alpha beta, or diluent resulted in minor changes in HEV morphology. By contrast, lymphocyte binding to HEV of GFM was more than doubled by the injection of IFN-gamma (1.95 +/- 0.25), P less than 0.01, but not IFN-alpha beta (0.54 +/- 0.07) or the relevant diluent controls (0.89 +/- 0.11, 0.56 +/- 0.06, respectively). It appears that the HEV binding ligand is inducible, and its expression is regulated by at least one immunomodulator, IFN-gamma. Although short-term exposure of HEVs to IFN-gamma influenced HEV function it caused only minor changes in morphology.

Animals↗
PubMed1988

Anti-Ia monoclonal antibody (10-2.16) inhibits lymphocyte-high endothelial venule (HEV) interaction.

Lymphocyte egress from the vascular compartment into the lymph node (LN) parenchyma occurs at the postcapillary venules, termed high endothelial venules (HEVs). Lymphocyte adhesion and migration through the HEVs is a receptor-mediated, energy-dependent, process. The aim of this study was to investigate the role of MHC Class II antigen expression on lymphocyte-HEV interaction in normal (CBA) and autoimmune (MRL/l) mice. Using the HEV binding assay, lymphocyte adhesion to LN sections pretreated with monoclonal antibody (MAb; 10-2.16) was decreased compared to diluent (mean of the differences +/- standard deviation; xd +/- SD: 0.749 +/- 0.22, P less than 0.0075)- and myeloma immunoglobulin-pretreated controls (xd = 0.462 +/- 0.13, P less than 0.005). Similar inhibition of binding was found in MRL/l LN sections pretreated with MAb 10-2.16. Binding inhibition was concentration dependent, but total inhibition was never achieved. Several other anti-Ia MAb's were used, but failed to inhibit lymphocyte attachment. Lymphocyte binding to control sections treated with MAb's against MHC Class I antigen, plasminogen activator (PAM-3), anti-thrombin III (AT-IIIm), and MECA-325 antigen was not significantly different from diluent controls. LN cell suspensions pretreated with MAb 10-2.16 bound normally to LN sections. By contrast, MAb to lymphocyte homing receptor (MEL-14) inhibited lymphocyte adhesion. The role of Class II antigens in lymphocyte-HEV interactions is discussed.

Animals↗