Yoshiki Kazama
Niigata University
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Featured researches published by Yoshiki Kazama.
Journal of Perinatal Medicine | 1998
Masaki Tamura; Koichi Takakuwa; Masato Arakawa; Masako Yasuda; Yoshiki Kazama; Kenichi Tanaka
To determine the relationship between mixed lymphocyte culture reaction (MLR) blocking antibodies (BAbs), immunological humoral factors, which generated in pregnant women and the outcome of pregnancy, the natural outcome of the third pregnancy in fifty-five patients with primary twice consecutive abortion was evaluated, and MLR-BAbs in sera were examined during their third pregnancy. The third pregnancy in 39 of 55 patients (70.9%) continued successfully, and remaining 16 patients (29.1%) experienced repeated abortion at the first trimester. Out of these 55 patients, MLR-BAbs were examined in 27 (17 with successful outcome and 10 with repeated abortion). The positive rate of MLR-BAbs was 82.4% in patients with successful outcome (15 of 17 cases), and that in patients with repeated abortion was 10% (one of 10 cases). The positive rate of MLR-BAbs was significantly higher in the successful pregnancy group compared with that in the repeated abortion group (p < 0.001). The blocking effect on MLR significantly increased along with the prenatal course in patients with successful outcome. Thus, MLR-BAbs are strongly associated with the outcome of pregnancy in patients with primary twice consecutive spontaneous abortions.
American Journal of Reproductive Immunology | 1993
Koichi Takakuwa; Masahiko Higashino; Masako Yasuda; Shiro Ishii; Hiroyuki Ueda; Kensaku Asano; Yoshiki Kazama; Kenichi Tanaka
PROBLEM: Is an additional immunotherapy necessary or not for patients who have obtained successful results after initial immunotherapy?
American Journal of Reproductive Immunology | 1993
Masako Yasuda; Koichi Takakuwa; Masahiko Higashino; Shiro Ishii; Yoshiki Kazama; Hiroshi Yoshizawa; Kenichi Tanaka
In the past few years a new concept concerning reproductive failure caused by autoimmune mechanisms has been recognized and accepted as a reproductive autoimmune failure syndrome (RAFS). I RAFS was first reported to include spontaneous abortion, endometriosis, and unexplained infertility, Recently, preeclampsia and intrauterine growth retardation have also been included in RAFS.2-4 In this report, the clinical course of a patient who was considered to be a typical case of RAFS is described, and the possibility of prophylactic therapy for patients of RAFS is discussed.
American Journal of Reproductive Immunology | 1992
Koichi Takakuwa; Masahiko Higashino; Hiroyuki Ueda; Kiyoshi Yamada; Kensaku Asano; Masako Yasuda; Shiro Ishii; Yoshiki Kazama; Kenichi Tanaka
ABSTRACT: The polymerase chain reaction‐restricted fragment length polymorphism (PCR‐RFLP) method was used for both examining compatibility at the HLA‐DQB1 gene locus and determining HLA‐DQ antigen polymorphism in spouses of unexplained recurrent abortions. Genomic DNA samples were prepared from peripheral mononuclear cells from patient and control couples. Two hundred and thirty base pair fragments of the second exon of the HLA‐DQB genes were selectively amplified. Amplified DNAs were digested with the restriction endonucleases, Fok I, Hae III, Hha I, Rsa I and Sau3A I, and subjected to electrophoresis in a polyacrylamide gel. The RFLPs showed that habitual aborters and their husbands had neither significantly frequent alleles nor shared common alleles at the HLA‐DQB locus when compared to the control group.
Journal of Reproductive Immunology | 1991
Koichi Takakuwa; Hiroyuki Ueda; Shigenori Goto; Isao Hasegawa; Kiyoshi Yamada; Yoshiki Kazama; Minako Kimura; Koji Kanazawa; Kenichi Tanaka
Changes in lymphocyte subsets in whole blood were analyzed sequentially by flow cytometry with an automated leukocyte differential system in 15 patients with unexplained recurrent spontaneous abortions, each of whom underwent vaccination(s) with her husbands lymphocytes. Mitogen responses of peripheral blood lymphocytes (PBL) were also examined in these patients. The reactivity of PBL against mitogens revealed no significant change in each patient before and after vaccination(s) with her husbands lymphocytes. The CD4:8 ratio was observed to decrease significantly during 22 and 28 days after the first vaccination with a significant increase in the percentage of T suppressor-cytotoxic (CD8) cells. This change was also observed after the second vaccination. The percentages of other subsets did not change significantly after vaccination(s). In 11 patients out of 15, the pregnancy continued successfully and correlated with a predominance of Ts/c (CD8) over TH/I (CD4) cells in the first trimester. These changes in lymphocyte subsets may indicate the induction of immune enhancing mechanisms and it is suggested that continuation of the predominance of Ts/c cells induced by immunotherapy might be important for the successful maintenance of pregnancy.
Human Reproduction | 1993
Shigenori Goto; Isao Hasegawa; Masahiko Higashino; Yoshiki Kazama; Kiyoshi Yamada; Koichi Takakuwa
Proceedings of Annual Meeting of JSIR | 1994
Isao Hataya; Masahiko Higashino; Kensaku Asano; Masako Yasuda; Yoshiki Kazama; Koichi Takakuwa; Kenichi Tanaka
Proceedings of Annual Meeting of JSIR | 1993
Koichi Takakuwa; Masahiko Higashino; Kensaku Asano; Masako Yasuda; Shiro Ishii; Yoshiki Kazama; Kenichi Tanaka
Proceedings of Annual Meeting of JSIR | 1993
Yoshiki Kazama; Masahiko Higashino; Kensaku Asano; Masako Yasuda; Shiro Ishii; Kiyoshi Yamada; Koichi Takakuwa; Kenichi Tanaka
Proceedings of Annual Meeting of JSIR | 1993
Masako Yasuda; Masahiko Higashino; Shiro Ishii; Naoto Sekizuka; Yoshiki Kazama; Koichi Takakuwa; Hiroshi Yoshizawa; Kenichi Tanaka