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Dive into the research topics where Ryuichi Yokohari is active.

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Featured researches published by Ryuichi Yokohari.


Clinical Immunology and Immunopathology | 1983

Human anticentriole autoantibody in patients with scleroderma and Raynaud's phenomenon.

Yasuoki Moroi; Ichiro Murata; Akiteru Takeuchi; Naoyuki Kamatani; Kiyoaki Tanimoto; Ryuichi Yokohari

Unique autoantibody was found in sera from two different patients that reacted with centrioles of both cultured mammalian cells and human peripheral leukocytes as detected by the indirect immunofluorescent method. Sera from the same individuals, one with scleroderma and the other suffering from Raynauds phenomenon, also stained the basal bodies of rat tracheal ciliated cells by the identical technique. Data from subsequent investigations have suggested that the antigen(s) involved in the reaction are water-insoluble protein(s) or polypeptide(s) associated with centrioles and are distinct from microtubular proteins or purine nucleoside phosphorylase.


Journal of Immunological Methods | 1982

A simple and rapid microenzyme-linked immunosorbent assay for antibodies to poly(ADP-ribose) in systemic lupus erythematosus

Yoshiyuki Kanai; Mitsuko Tauchi; Shinichi Aotsuka; Ryuichi Yokohari

A simple and rapid microenzyme-linked immunosorbent assay has been developed for determination of anti-poly(ADP-ribose) antibodies in humans using a combination of protein A-alkaline phosphatase conjugates and poly(ADP-ribose)-coated polyvinyl microplates. After a 1-h treatment of the plates with 100 microliters of poly L-lysine (PLL) solution (50 micrograms/ml), an aliquot of the solution containing 100 ng poly(ADP-ribose) (50 microliters) was added to the PLL-treated plates and evaporated at 37 degrees C overnight to facilitate the adherence of poly(ADP-ribose) to the plates. Nonspecific binding of diluted test sera from patients with systemic lupus erythematosus (SLE) or from normal individuals to the PLL-coated plates was minimized by exposure of the plates for 1 h to Tris-buffered saline (pH 7.4) containing 0.01% bovine serum albumin (BSA). This method was also applicable to the determination of anti-double-stranded DNA antibodies in humans. The present assay is advantageous over those reported so far as it saves time and antigen.


Journal of Immunological Methods | 1984

C1q solid-phase radioimmunoassay: Binding properties of solid-phase C1q and evidence that C1q-binding IgG complexes in systemic lupus erythematosus are not bound to endogenous C1q

Shu Uwatoko; Shinichi Aotsuka; Masako Okawa; Yasuo Egusa; Ryuichi Yokohari; Chikara Aizawa; Keiji Suzuki

The binding properties of C1q solid-phase radioimmunoassay (C1q SPRIA) were examined, using heat-aggregated IgG (HAG) as the model of immune complexes (IC). The free, liquid-phase C1q, which was added to the C1q-coated tubes prior to the addition of HAG, had little inhibitory effect on binding of HAG to the solid-phase C1q, suggesting that the solid-phase C1q has a higher affinity for HAG than the liquid-phase C1q. On the other hand, more than 60% inhibition was seen when HAG was preincubated with the liquid-phase C1q. These binding properties of HAG to the solid-phase C1q in the presence of the liquid-phase C1q were not essentially altered by the heat inactivation or the addition of EDTA, suggesting that these pretreatments are not essential in C1q SPRIA. Next, in similar kinds of experiments, the binding properties of C1q-binding IgG complexes in SLE sera were investigated. In contrast to HAG, the binding capacity of IgG complexes in SLE sera to the solid-phase C1q was not inhibited by the preincubation with excess liquid-phase C1q. These findings suggest that C1q-binding IgG complexes in SLE sera detected by C1q SPRIA may not be bound to endogenous C1q in the circulation.


Journal of Immunological Methods | 1981

Anti-double strand (ds) DNA antibody formation by NZB/W (F1) spleen cells in a microculture system detected by solid-phase radioimmunoassay

Hirokazu Okudaira; Eiji Terada; Tadaatsu Ogita; Shinichi Aotsuka; Ryuichi Yokohari

A solid-phase radioimmunoassay method was devised to detect mouse anti-double strand (ds) DNA antibody. This method could easily detect the anti-dsDNA antibody in 1 : 10,000 dilutions (1 unit) of pooled 9-10-month-old female NZB/W F1 sera. The sensitivity was about 10(3)- and 10(2)-fold higher than that of the modified Farr method and of the double antibody technique respectively. NZB/W mice developed high titer anti-dsDNA antibody as they grew older. Spleen cells brought to a microculture system using flat-bottomed polystyrene plates produced anti-dsDNA antibody clearly detectable by solid-phase radioimmunoassay. Anti-dsDNA antibody produced in vitro (y units) was in close correlation with the anti-dsDNA antibody titer of the spleen donor (x units) (y = 4.8 X 10(-2) x -65, gamma = 0.94, P less than 0.001). A combination of the microculture system and solid-phase radioimmunoassay was recommended for the characterization of anti-dsDNA antibody-forming cells.


International Journal of Immunopharmacology | 1991

Suppressive effect of anti-rheumatic drugs on interleukin-1β release from human peripheral blood monocytes

Masahiro Okamoto; Minoru Sasano; Makoto Goto; Kusuki Nishioka; Shinichi Aotsuka; Keiko Nakamura; Ryuichi Yokohari

We developed an ELISA system for human IL-1 alpha and -beta release from silica-stimulated monocytes from healthy volunteers and tested the effect of several anti-rheumatic drugs including nonsteroidal anti-inflammatory drug (Ibuprofen). Anti-rheumatic drugs including Auranofin and Sulphasalazine suppressed IL-1 beta release significantly at therapeutic concentrations, whereas Bucillamine, Lobenzarit, D-Penicillamine and Ibuprofen did not. These results suggest a possible immunotherapeutic effectiveness of some anti-rheumatic drugs on rheumatoid arthritis through their inhibition of IL-1 beta release.


Clinical Immunology and Immunopathology | 1988

Monocyte-mediated suppression of rheumatoid factor production in normal subjects

Masako Okawa-Takatsuji; Shinichi Aotsuka; Shu Uwatoko; Ryuichi Yokohari; Katsuhiko Inagaki

The regulatory role of normal monocytes in the production of rheumatoid factor (RF) was investigated. Monocyte depletion from normal mononuclear cells (MNC) resulted in an elaboration of IgM RF in 18 of 20 subjects. The increased RF production was inhibited by the addition to the cultures of adherent cells or their culture supernatants. These observations demonstrate the suppressive role of normal monocytes in the production of RF. Supernatants obtained from normal monocytes cultured with indomethacin could suppress the RF production, suggesting that prostaglandin E2 may not be involved in the regulation of IgM RF production.


International Journal of Immunopharmacology | 1991

Interleukin-1β release from human peripheral blood monocytes associated with phagocytosis of carbonyl-iron or erythrocytes

Masahiro Okamoto; Minoru Sasano; Makoto Goto; Kusuki Nishioka; Shinichi Aotsuka; Keiko Nakamura; Ryuichi Yokohari; Terumasa Miyamoto

Interleukin-1 beta (IL-1 beta) release from human peripheral blood monocytes during the incubation with carbonyl-iron or sheep red blood cells was investigated. The incubation of purified monocytes with carbonyl-iron or sheep red blood cells enhanced IL-1 beta release, while their compounds, hemoglobin, globin and ferric citrate did not. The mechanisms of IL-1 beta release by carbonyl-iron or sheep red blood cells may be related to their phagocytosis, as non-phagocytic monocytes did not release IL-1 beta.


Immunochemistry | 1973

Heat-polymerization of human immunoglobulin G

Ryuichi Yokohari; Koyo Takeda; Yukio Imamura

Abstract When added to heated immunoglobulin G solution, rivanol precipitated polymerized immunoglobulin G, leaving the unpolymerized material in the supernate. Using this property of rivanol, kinetic studies on heat-polymerization of normal immunoglobulin G disclosed two types of immunoglobulin G differing in rate of polymerization by heat. Experiments using myeloma sera showed, however, that monoclonal immunoglobulins G exhibited a wide range of rate constant of heat-polymerization, which was not related to immunological subclass, L chain type or electrophoretic mobility. It appears that the two types present in polyclonal immunoglobulins G may correspond to two distributions of immunoglobulin G with different rate constant of heat-polymerization.


Archive | 1987

Occurrence of Antibody against Calmodulin in Chronic Liver Diseases

Yusei Ikeda; Shinichi Aotsuka; Gotaro Toda; Ryuichi Yokohari; Hiroshi Oka

SummarySera from patients with liver diseases, collagen diseases, and malignant neoplasms were examined for autoantibody to calmodulin (anti-CaM). Calmodulin (CaM) was fixed to a polystyrene plate, incubated with appropriately diluted sera, and then the presence of IgG, IgM, and IgA bound to fixed CaM was determined with horseradish peroxidase-conjugated rabbit anti-human IgG, IgM, and IgA serum. IgG class anti-CaM was detected in none of the normal healthy subjects, whereas IgM and IgA class antibodies were detected in 5.0% and 4.3% of them, respectively, though their titres were low. IgG class antibody showed no disease specificity, although it was more frequently found in patients with liver diseases (51.2%), collagen diseases (25.2%), and malignant neoplasms (41.2%) than in healthy subjects. The frequencies of IgM class antibody were 36.6%, 3.9%, and 0% in the patients with liver diseases, collagen diseases, and malignant neoplasms, respectively. Thus, IgM class antibody was shown to be specific for liver diseases. Among the patients with liver diseases, the frequency was the highest in those with liver cirrhosis. The frequency of IgA class antibody was significantly higher in patients with liver diseases (28.9%) and collagen diseases (15.5%) than in healthy subjects (4.3%), whereas that in the patients with malignant neoplasms was not. Pretreatment of sera with CaM decreased the titer of anti Ca-M, whereas pretreatment with actin or calf thymus DNA did not.


Kanzo | 1987

The significance of autoantibody against calmodulin in chronic liver diseases, collagen diseases and malignant neoplasmas.

Yusei Ikeda; Gotaro Toda; Toshiyuki Maruyama; Naoki Hashimoto; Hiroshi Oka; Shinichi Aotsuka; Ryuichi Yokohari

慢性肝疾患,膠原病,悪性腫瘍における仔牛より精製したカルモデュリン(CaM)に対する自己抗体の出現を報告した.抗CaM抗体の測定は酵素抗体法によった.抗体陽性血清と,CaM結合アガロースとを反応させ,酸性グリシンによる溶出分画中に,抗CaM抗体活性を認めた.抗体活性は,アクチン,仔牛胸腺DNAによる吸収では,低下しなかったが,CaM,家兎肝細胞膜分画および肝ホモジュネート77,000g上清分画による吸収で,低下した.IgGクラスの抗体は,肝疾患51.2%,膠原病25.2%,悪性腫瘍41.2%に認め,正常人(0%)より高頻度であった.IgMクラスの抗体は,それぞれ36.9%, 3.9%, 0%, 5%で,肝疾患,特に肝硬変は高頻度であった(p<0.02). IgAクラスの抗体は,肝疾患(28.9%),膠原病(15.5%)で,正常者(4.3%)より高頻度であった.抗平滑筋抗体の出現とは相関しなかった.

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Gotaro Toda

Jikei University School of Medicine

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Makoto Goto

Toin University of Yokohama

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Kusuki Nishioka

St. Marianna University School of Medicine

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