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Biomedical subjects

M Harigai

Publications and source records attributed to M Harigai.

At least 55 records · Page 3Linked to original sources

[A case of antiphospholipid syndrome associated with left subclavian artery thrombosis and left external iliac vein thrombosis].

Arterial thrombosis is one of the major symptoms of antiphospholipid syndrome (APS). However, thrombosis in a primary branch of the aorta has rarely been reported in APS. We report here a case of APS complicated by thromboses in both the left subclavian artery and the left external iliac vein. A 32-year-old woman was admitted in May, 1990 complaining of no pulse in the left superficial arteries (e.g., left radial artery) for the past 5 years and acute swelling of the left lower extremity. A left ascending phlebography showed an occlusion of the external iliac vein and arteriography revealed obstruction in the left subclavian artery. Collateral circulations were developed at the site of each thrombus. Clotting and immunological studies revealed a prolonged APTT, a high titer of anticardiolipin antibody and lupus anticoagulant positive. We ruled out various diseases and clinical risk factors predisposing to both arterial and venous thromboses. Accordingly, we concluded that both thromboses were based on APS. Following treatment with anticoagulants, aspirin and corticosteroid, the swelling of her left thigh was diminished and the antibody titer was decreased within 3 months.

Adult↗

Continuous removal of anti-DNA antibody, using a new extracorporeal immunoadsorption system, in patients with systemic lupus erythematosus.

We performed selective and continuous immunoadsorption of anti-DNA antibodies from the blood of 6 patients with systemic lupus erythematosus, using a newly developed extracorporeal immunoadsorption system equipped with twin dextran sulfate-cellulose columns with an automated regenerating unit. Levels of anti-DNA, which were initially high, were rapidly diminished after 2-4 apheresis procedures in each patient; in 3 patients with proteinuria and 4 patients with lymphocytopenia, these symptoms also improved. Analysis of the kinetics and the adsorbed amounts of anti-DNA during the apheresis indicates that both the intravascular and the extravascular pool of anti-DNA are reduced with this potent apheresis technique.

Adult↗

Interleukin 5 up-regulates high-affinity interleukin 2 receptor expression by human resting peripheral T cells: a comparison with the effect of interleukin 4 on B cells.

The separate regulation mechanisms of cytokines on two classes of interleukin 2 receptors (IL-2R) on human peripheral T and B cells were analyzed by a flow cytometer using a double stain with IL-2R alpha (55 kilodalton Tac) and IL-2R beta (75 kilodalton mik beta 1, mik beta 3). Although the expression of IL-2R alpha by T cells was slightly enhanced by IL-2 and IL-4, expression of the beta chain was diminished by both cytokines. IL-5 by itself did not alter the expression of either IL-2R alpha or beta, but preculturing with IL-2 for 24 h followed by IL-5 for another 24 h induced an increase in IL-2R alpha expression and in simultaneous alpha/beta chain expression. Increased numbers of high-affinity IL-2R were confirmed by 125I binding assays. On B cells, IL-4 increased alpha, beta, and simultaneous alpha/beta chain expression, but IL-4-treated B cells did not show an increased number of high-affinity IL-2R.

B-Lymphocytes↗

Discrete association of CD3 and CD4 molecules in T-cell stimulation acting through the autologous mixed lymphocyte reaction and the CD3/T-cell receptor complex in human autoreactive T-cell clones.

To investigate autologous antigen recognition, we developed two autoreactive CD4+ T-cell clones, A2 and A10, maintained with non-T cells and IL-2. Autologous non-T-cell stimulation of the T-cell clones resulted in a decrease in cell surface expression of CD4, whereas the expression of CD2, CD3, and WT31 was unchanged. Activation of the autoreactive T-cell clones by cell surface binding anti-CD3 MoAb, as a specific antigen stimulator of the T-cell receptor complex, induced cell surface antigen comodulation of CD3, CD4, and WT31. These data suggest a discrete association of CD3 and CD4 molecules in T-cell stimulation, acting through the autologous mixed lymphocyte reaction and the CD3/T-cell receptor complex. PMA treatment resulted in concomitant down-regulation of CD3 and CD4 but calcium ionophore treatment did not. Thus, it appears that phosphorylation of CD3 leads to the down-regulation of surface antigens of CD4.

Antibodies, Monoclonal↗

Flow cytometric analysis of lipid droplet formation in cells of the human monocytic cell line, U937.

Active uptake of a free fatty acid, oleate, and its incorporation into triacylglycerol and phospholipid in the human monocytic cell line, U937, was identified using 14C-labelled oleate. Excess triacylglycerol accumulates in the form of lipid droplets in the cytoplasm. The extent of lipid droplet formation in each cell can be assessed in the absence of any staining by 90 degrees light scatter intensity, one of the basic parameters of flow cytometry.

Cell Line, Transformed↗

Interleukin 1 and tumor necrosis factor-alpha synergistically increase the production of interleukin 6 in human synovial fibroblast.

We have previously reported that synovial cells could participate in B cell differentiation processes in rheumatoid arthritis (RA) by producing interleukin-6 (IL-6) spontaneously or in response to interleukin-1 (IL-1) stimulation. In this paper, we examined the effects of tumor necrosis factor-alpha (TNF-alpha) on IL-6 production by human synovial fibroblasts. TNF-alpha, as well as IL-1, is a putative relevant molecule in the inflammatory process and in articular destruction in RA. Both IL-1 and TNF-alpha induced IL-6 production by synovial fibroblasts in a dose dependent manner. When synovial fibroblasts were stimulated by IL-1 and TNF-alpha in combination, IL-6 production increased synergistically after 48 hr of a 72 hr culture period. Kinetic studies revealed that the presence of both cytokines at the early phase of stimulation was required for the synergistic effect. These results suggest that TNF-alpha could be involved in a cytokine network in the affected joints of RA and could contribute synergistically with IL-1 to the IL-6 production by synovial fibroblasts in vivo.

Arthritis, Rheumatoid↗

[A case of pregnant woman with lupus anticoagulant positive systemic lupus erythematosus complicated with intrauterine fetal death, eclampsia, and brainstem vascular damage].

A 28-year-old female patient with SLE was found to have complications from intrauterine fetal death, eclampsia, and brainstem vascular damage during pregnancy. These symptoms were associated with lupus anticoagulant (LAC). An LAC positive SLE case with accompanying cerebrovascular disease and fetal loss at the same time has rarely been reported. The first brain CT scan revealed the presence of multiple middle pons infarction. Ten days after onset, a brain MRI showed the change into hemorrhagic infarction in the same region, suggesting disseminated intravascular coagulation (DIC) caused by severe obstetric complications. Although the severity of the brain damage implied poor prognosis, her symptoms were alleviated by intensive care with a large amount of steroid therapy and active rehabilitation. LAC-positive SLE patients are apt to encounter obstetric complications in pregnancy. Therefore they must be treated by medical specialists in cooperation with gynecologists. When they also have accompanying with cerebrovascular diseases, active therapy for SLE is necessary for a good prognosis.

Adult↗

Augmentation of LDL receptor activities on lymphocytes by interleukin-2 and anti-CD3 antibody: a flow cytometric analysis.

Dormant lymphocytes are known to show little LDL receptor (LDL-R) activities. The present study was designed to determine whether or not LDL-R activities of lymphocytes from normal subjects were high enough to be measured by flow cytometry after the cells had been stimulated with recombinant interleukin-2 (IL-2) and anti-CD3 monoclonal antibody (mAb). IL-2 or anti-CD3 mAb individually provokes proliferation of lymphocytes in a serum-free medium. Proliferation rate was accelerated when the two reagents were used in combination. Stimulated cells cultured for 5 days expressed more than 85% CD3 positive, less than 0.5% CD14 positive, and less than 1.5% CD20 positive. The LDL-R activities of the cells were examined by the uptake of a fluorescence probe, DiI-labeled LDL (DiI-LDL) and analyzed by flow cytometry. Stimulated cells showed increased uptake of DiI-LDL and 84 +/- 9% were positive, whereas only 3.0 +/- 2.5% of the cells without stimulation were positive (P less than 0.001). Under the same conditions stimulated lymphocytes from a homozygous familial hypercholesterolemia (FH) patient showed little LDL-R activities; 14% of the cells were positive. Displacement assays reveal that the uptake of LDL by these cells is occurring by way of its specific pathway. These data imply the lymphocytes stimulated with the reagents used in the study might be used for detecting defects in LDL-R, perhaps defects in other genomic systems as well.

Antibodies, Monoclonal↗

Characterization of human monocytic cell line, U937, in taking up acetylated low-density lipoprotein and cholesteryl ester accumulation. A flow cytometric and HPLC study.

The uptake of LDL and acetylated LDL and the ability of cholesteryl ester accumulation by cells of a human monocytic cell line, U937, has been characterized by flow cytometric assay using a fluorescent probe, DiI, and by high-performance liquid chromatography (HPLC). The increase of mean fluorescence intensity of U937 incubated with DiI-labeled lipoproteins demonstrates that this cell line could incorporate DiI-AcLDL, as well as DiI-labeled LDL. Competition and saturation studies indicate that the manner of taking up DiI-AcLDL is receptor-mediated. While differentiated U937 incubated with 16 nM phorbol myristate acetate for 24 h took up little DiI-AcLDL, HPLC analysis confirmed that intracellular free and esterified cholesterols significantly increase in the U937 cells incubated with AcLDL or LDL. The ability of mouse peritoneal macrophage to abundantly accumulate at least five kinds of cholesteryl ester were also shown in this analysis. In contrast, in U937 cells, free fatty acids are incorporated into various substances rather than into cholesteryl esters (as revealed by HPLC analysis), so that the cholesterol in AcLDL taken up by U937 cells is not synthesized into cholesteryl esters to any great extent.

Acetylation↗

Pretreatment of human vascular smooth muscle cells with interleukin-1 enhances interleukin-6 production and cell proliferation (action of IL-1 on vascular smooth muscle cells).

Systemic vasculitis is an inflammatory disorder of blood vessels characterized by a perivascular mononuclear cell infiltration around the vessel and fibrinoid necrosis within vessel walls. Interleukin-1 (IL-1) is a multipotent inflammatory mediator and affects several properties of vascular cells. To determine whether IL-1 could contribute to the pathogenesis of vascular diseases, we examined the effect of IL-1 on B cell stimulatory factor-2/interleukin-6 (IL-6) production by cultured human vascular smooth muscle cells (SMC) and the proliferation of these cells. Supernatants of SMC stimulated IgM synthesis of human B cell line. SKW6-CL4 cells. This activity was increased (1.7 to 2.6-fold) when SMC were pretreated with IL-1 or calcium ionophore A23187 for 48 h, and was completely blocked by rabbit anti-human IL-6 antibodies. These IL-6 activities of the SMC supernatants were also assessed by using an IL-6 dependent murine hybridoma cell line. MH-60. BSF-2. In addition, we observed that pretreatment of SMC with IL-1 for 48 h stimulated growth of SMC during the 96 h incubations, as assessed by cell number (p less than 0.05). These results suggest that IL-1 may contribute to the pathogenesis of inflammatory and immunological vasculitis by the augmentation of IL-6 release and growth of SMC.

Calcimycin↗

[A case of systemic lupus erythematosus complicated with multifocal posterior pigment epitheliopathy].

Multifocal posterior pigment epitheliopathy (MPPE) is a rare complication of systemic lupus erythematosus (SLE) and resistant to treatment. We here report a case of SLE with MPPE, successfully treated with prednisolone (PSL) and laser photocoagulation therapy. A 38-year-old woman, who had suffered from SLE for four years, was admitted to our hospital with the complaints of left hemiparesis, right homonymous hemianopsia, and dysarthria. The findings of MRI suggested her symptoms were caused by cerebrovascular involvement of SLE. The treatment with prednisolone was started at a dose of 100 mg per day. While the dose of PSL was reduced, she began to complain of paresthesia in left face and myodesopsia of left eye. Based upon the result of fluorescein angiogram, the diagnosis of MPPE was made. Since MPPE accompanied exacerbation of neurological manifestation, we considered that MPPE was a symptom of vascular involvement of SLE. MPPE was treated with laser photocoagulation therapy and an increased dosage of PSL, with favorable results. It has not been reported, as far as we concern, that laser photocoagulation therapy is effective for MPPE caused by SLE. This case is important for the pathogenesis and therapy of MPPE with SLE.

Adult↗

Elevated plasma levels of alpha 2-plasmin inhibitor-plasmin complex in patients with rheumatic diseases. Possible role of fibrinolytic mechanism in vasculitis.

Plasma levels of alpha 2-plasmin inhibitor (alpha 2PI) and alpha 2-plasmin inhibitor-plasmin complex (alpha 2 PIPC) were measured by sandwich enzyme-linked immunosorbent assay, using a recently developed monoclonal anti-alpha 2PI antibody, in patients with collagen diseases. Twenty patients had systemic lupus erythematosus (SLE), 4 of whom also had vasculitis, 11 patients had rheumatoid arthritis (RA), 4 of whom also had vasculitis, and 5 patients had other types of vasculitis. There was no significant difference in alpha 2PI levels between the 3 patient groups and the control groups. However, plasma levels of alpha 2PIPC in all 3 patient groups were significantly higher than those in the control group. Moreover, plasma concentrations of alpha 2PIPC in SLE patients with vasculitis were statistically significantly higher than those in SLE patients without vasculitis. These concentrations were also higher in RA patients with vasculitis than in RA patients without vasculitis, although the difference was not statistically significant. Our findings indicate that measurement of plasma alpha 2PIPC levels is useful for detecting and evaluating the severity and activity of vasculitis in patients with collagen diseases.

Adolescent↗

Expression of TLiSA1 on T cells from patients with rheumatoid arthritis and systemic lupus erythematosus.

The expression of a new activation antigen, T cell lineage specific activation antigen (TLiSA1) on peripheral blood T cells from 16 rheumatoid arthritis (RA) and 8 systemic lupus erythematosus (SLE) patients and synovial fluid T cells from RA patients was determined in the context of T cell activation. The percentages of TLiSA1 positive T cells from inactive (4.6 +/- 5.2, mean +/- SE) or active RA (19.3 +/- 8.6) or inactive (1.7 +/- 2.1) or active SLE (8.7 +/- 2.7) were significantly increased compared with that of normal controls (0.7 +/- 0.4) (P less than 0.01). All patients with vasculitis showed relatively high positive percentages. The mean fluorocytometric intensity of TLiSA1 positive T cells from RA and SLE patients was significantly higher than that from normals. Percentages of TLiSA1 positive T cells from synovial fluids (21.8 +/- 4.9%) were significantly increased compared with those from peripheral blood of the same patients, indicating the local activation of T cells in patients with RA. An increase in the expression of TLiSA1 with no increase in the expression of the very late activating antigen 1 (VLA-1) was found in peripheral blood from RA, suggesting a difference in the stage of T cell activation in RA. In RA, there was a clinical correlation with levels of TLiSA1 expression on peripheral T cells. After stimulation with PHA, TLiSA1 positive percentages were increased on Day 2 and continued to increase through 5 days of culture. The maximum expression was obtained on Day 5. An increased number of TLiSA1 positive T cells belonged to OKT8. These results suggest that there is the systemic and the local activation of T cells in RA, following antigen stimulation, or a generalized nonspecific activation of immune system that could provide a means to monitor the abnormal immunologic activity in RA.

Antigens, Differentiation, T-Lymphocyte↗

Stimulation of interleukin 6-like B-cell differentiation factor production in human adherent synovial cells by recombinant interleukin 1.

Abnormal production of immunoglobulin in the joint space is frequently observed in patients with rheumatoid arthritis (RA). We have previously demonstrated that adherent synovial cells (ASC) from patients with RA are involved in B-cell differentiation by their spontaneous production of B-cell differentiation factor (BCDF). The regulation of the production of this factor, however, has not yet been described. We investigated the effects of recombinant interleukin 1 alpha and beta (rIL-1 alpha and rIL-1 beta) on the production of BCDF in ASC. Increased production of BCDF was observed with increased rIL-1 concentration. Production of BCDF was detected 3 h after exposure of ASC to rIL-1 and increased throughout a 48-h culture. This BCDF, assayed on SKW6-CL4 cells, was found to share a common active site with interleukin 6. The effect of rIL-1 was almost neutralized by anti-IL-1 antibody and the addition of polymyxin B did not diminish the effect of rIL-1, indicating that rIL-1 itself stimulates ASC in vitro. These results suggest that IL-1 may play a regulatory role in the production of BCDF in synovial tissue.

Cell Adhesion↗

Coated fibronectin induces adhesion in the human monocytic cell line U937.

The differentiation inducing effect of coated human fibronectin (HFN) on U937 was investigated. U937 cells usually proliferate without stimuli. HFN induced the adhesion of about 20% of U937 cells in a serum free medium. HFN did not inhibit cell growth nor induce CD14 expression. The adhesion inducing activity of HFN was completely blocked by addition of anti-HFN antibody. Phorbor 12-myristate 13-acetate (PMA), another differentiation inducing agent, inhibited the growth of U937 cells but did not induce adhesion in the serum free medium. These data imply that HFN has a differentiation inducing effect on a human monocytic cell line and could be used as a biological response modifier.

Antigens, Differentiation, Myelomonocytic↗

[Analysis of systemic lupus erythematosus (SLE) involving the central nervous system by magnetic resonance imaging (MRI)].

Involvement of the central nervous system (CNS) commonly occurs in systemic lupus erythematosus (SLE). But definitive diagnosis remains difficult even with computed tomography (CT). In this study, we used the recently developed technique, magnetic resonance imaging (MRI) for CNS lupus and compared it with CT scans. CT was performed with a General Electric 8800 CT/T scanner. MRI was performed using a Mitsubishi Electric MMI-150 S. Ten patients with CNS lupus were divided into 3 groups. Group I included 4 cases with neurological manifestations alone. All lesions seen on CT were also detected by MRI, with greater clarity and extent. Furthermore, MRI depicted several microinfarcts in white matter without symptoms. Group II included 5 cases with psychiatric features alone. MRI detected a thalamic microinfarct in only one case while CT showed no abnormality in all cases. Group III included 1 case with both neurological and psychiatric symptoms. MRI demonstrated a small infarct of midbrain corresponding with neurological symptoms, more clearly than CT. Therefore MRI demonstrates the degree of brain involvement in SLE more accurately than CT.

Adult↗