Keisuke Sawai
Osaka University
Network
Latest external collaboration on country level. Dive into details by clicking on the dots.
Publication
Featured researches published by Keisuke Sawai.
Gynecologic Oncology | 2003
Namiko Yada-Hashimoto; Toshiya Yamamoto; Shoji Kamiura; Hozumi Seino; Hiroki Ohira; Keisuke Sawai; Tadashi Kimura; Fumitaka Saji
OBJECTIVE The goal was to review cases of metastatic ovarian tumor with respect to their clinical features. METHODS Sixty-four patients with pathologically confirmed metastatic ovarian carcinoma, who were treated between 1978 and 2002 at Osaka Medical Center for Cancer and Cardiovascular Diseases (OMCC), were reviewed and the clinical features examined. RESULTS We found that metastatic tumors accounted for 21.1% (64/304) of malignant ovarian tumors. Of 64 metastatic ovarian tumors, 26 originated from gynecologic organs, and 38, from nongynecologic organs. Gynecologic primary sites were the uterine body (23%), uterine cervix (14%), and fallopian tube (3%). Eight of nine cervical cancers with ovarian metastases were adenocarcinomas. Adenocarcinoma of the uterine cervix metastasized to the ovaries more frequently than squamous cell carcinoma (5.6% vs 0.1%, respectively; P < 0.01). Among 38 cases of metastatic ovarian tumors from nongynecologic organs, Krukenberg tumors, pathologically characterized by the presence of typical signet-ring cells, were found in 11 patients (29%). Most (8/11) had originated in the stomach. Half (19/38) were preoperatively diagnosed as metastases. The 5-year survival rate after resection of metastatic ovarian tumors from gynecologic organs was significantly higher than the rate after resection of such tumors from nongynecologic organs (47% vs 19%, respectively; P = 0.026). CONCLUSIONS Metastatic ovarian tumors are likely to be relatively common in Japan because of the high incidence of gastric cancer. In cases of pelvic tumor, metastatic ovarian tumor should always be included in the differential diagnoses. As the 5-year survival after resection of metastatic ovarian tumor is 19%, even for tumors from nongynecologic organs, it seems worthwhile to consider tumorectomy as the second cytoreduction.
Placenta | 1990
Takashi Kameda; Noboru Matsuzaki; Keisuke Sawai; Takayoshi Okada; Fumitaka Saji; Tadashi Matsuda; Toshio Hirano; Tadamitsu Kishimoto; Osamu Tanizawa
The placenta plays a number of important roles during pregnancy, some of which might be mediated by cytokines with multiple activities such as IL-6. Using an IL-6-dependent cell line, MH6o.BSF2, we showed that the placenta released IL-6 into the culture supernatant. Analysis of single-cell suspensions of placental cells determined the major source of IL-6 to be trophoblast. Using a mouse monoclonal antibody specific for IL-6 (alpha BSF2-I66), immuno-histochemical analysis of placental specimens demonstrated the localization of IL-6 only in the trophoblast layer. Additional immunocytochemical studies with single-cell suspensions of trophoblasts demonstrated the preferential presence of IL-6 molecules in syncytiotrophoblasts rather than cytotrophoblasts. The evidence that a high titer of IL-6 is produced spontaneously by syncytiotrophoblasts indicates that IL-6 may play immunological roles in fetomaternal interactions by means of IL-6-driven multiple immunoregulatory activities.
American Journal of Reproductive Immunology | 1996
Toshikatsu Nobunaga; Yoshihiro Tokugawa; Kazumasa Hashimoto; Yasue Kubota; Keisuke Sawai; Tadashi Kimura; Koichiro Shimoya; Masahiko Takemura; Noboru Matsuzaki; Chihiro Azuma; Fumitaka Saji
PROBLEM: To evaluate the “effect of nitric oxide in the seminal plasma on sperm motility. METHOD: Seminal plasma concentrations of NO2—, a stable end product of nitric oxide, of 108 males of infertile couples and 15 proven fertile donors were measured and compared with spermatogram parameters. Motile sperm was incubated with a nitric oxide‐generating drug, sodium nitroprusside, for 6 hr in the absence or presence of oxyhemoglobin, an inhibitor of nitric oxide.
American Journal of Reproductive Immunology | 1995
Kouichiro Shimoya; Noboru Matsuzaki; Nobuo Ida; Takayoshi Okada; Takeshi Taniguchi; Keisuke Sawai; Shinichi Itoh; Kazutomo Ohashi; Fumitaka Saji; Osamu Tanizawa
PROBLEM: To demonstrate whether monocyte chemotactic and activating factor (MCAF) and interleukin‐6 (IL‐6) are present in the seminal plasma, and whether these presence is modulated by leukospermia.
Gynecologic and Obstetric Investigation | 1996
Kazumasa Hashimoto; Chihiro Azuma; Shoji Kamiura; Masayasu Koyama; Toshikatsu Nobunaga; Yoshihiro Tokugawa; Tadashi Kimura; Yasue Kubota; Keisuke Sawai; Fumitaka Saji
The insulin-like growth factor II gene (IGF2) is thought to be involved in the growth of uterine smooth muscle tumors. We studied the allele-specific expression of IGF2 in 20 patients with uterine leiomyomas by analyzing restriction fragment length polymorphisms (RFLP), because IGF2 is a maternally imprinted gene and only the paternal allele is exclusively expressed in human somatic tissue. We also studied the allelic expression of the small nuclear ribonucleoprotein polypeptide N gene (SNRPN), which is reportedly maternally imprinted in humans, and compared the imprinting status with that of IGF2. Nine patients (45%) were heterozygous at the ApaI site of IGF2, nine (45%) were heterozygous at the possible AccII polymorphic site of SNRPN, and three (15%) showed polymorphism in both genes. The genomic DNA of 15 patients showed heterozygosity in either or both of these genes, and the mRNA of these was expressed monoallelically in myometrial tissues and leiomyomas of these patients. These results demonstrated that IGF2 and SNRPN imprinting is completely maintained in human uteri and leiomyomas and that increased expression of IGF2 is not due to biallelic expression.
Cellular Immunology | 1989
Noboru Matsuzaki; Fumitaka Saji; Takayoshi Okada; Keisuke Sawai; Takashi Kameda; Toshio Tanaka; Shigeru Negoro; Osamu Tanizawa
We examined the nature of cytoplasmic signal transduction pathways in cord blood T cells by stimulating them with tumor promoter (TPA) and calcium ionophore (A23187). Costimulation of T cells with TPA and A23187 induced optimal proliferative responses on Day 2 in cord T cells but on Day 4 in adult T cells. The maximal responses observed in cord T cells were much less than those of adult T cells, whereas the Con A-induced proliferative responses of these cells showed no significant differences. The reduced responses of cord T cells were due to their lower efficiency in activating the cellular events in T cell activation and proliferation phase, because cord T cells have significantly less ability than adult T cells to express IL-2 receptor as well as HLA-DR and produce IL-2 molecules, thereby inducing proliferation. These data show immature characteristics of intracellular signal transduction pathways in cord T cells, which are directly related with the functional immaturity of cord T cells.
Journal of Reproductive Immunology | 1991
Noboru Matsuzaki; Fumitaka Saji; Takayoshi Okada; Keisuke Sawai; Takashi Kameda; Osamu Tanizawa
The immunosuppressive activity of a JEG-3 choriocarcinoma-derived factor in human IL-2-dependent T cell responses has been studied, together with its effect on IL-2-independent T cell responses induced by 10 nM TPA. The factor completely suppressed the IL-2-independent proliferative responses of T cells but failed to suppress antigenic expression of activation-associated CD 25 molecules. Further studies examined the effect of the factor on LAK cell generation induced by rIL-2. Recombinant IL-2-induced LAK cell proliferation was observed on Day 4 and Day 5, but not on Day 3. As the factor suppressed the responses of LAK cell proliferation, we tested whether it blocked the generation of Day 3, Day 4 and Day 5 LAK cells. The addition of the factor failed to suppress the generation of Day 3 LAK cells, while it partially suppressed the lytic activity of Day 4 LAK cells and completely suppressed that of Day 5 LAK cells. The data suggest the presence of a heterogeneous pattern for LAK cell generation; one without proliferation, but the other requiring proliferation, to acquire killer activity. Taken together with the evidence that the factor failed to suppress NK activity, the choriocarcinoma-derived factor suppressed only the proliferative events of immunocompetent cells, but inhibited neither their activation nor the differentiation events. This immunosuppressive factor might be involved in the prevention of host-mediated rejection of choriocarcinoma cells or maternal rejection of the fetus.
Journal of Reproductive Immunology | 2000
Fumitaka Saji; Yoshihiro Samejima; Shoji Kamiura; Keisuke Sawai; Koichiro Shimoya; Tadashi Kimura
The Journal of Clinical Endocrinology and Metabolism | 1995
Keisuke Sawai; Noboru Matsuzaki; Takashi Kameda; Kunihiko Hashimoto; Takayoshi Okada; K. Shimoya; Toshikatsu Nobunaga; Tetsuya Taga; Tadamitsu Kishimoto; Fumitaka Saji
Biology of Reproduction | 1997
Keisuke Sawai; Noboru Matsuzaki; Takayoshi Okada; Koichiro Shimoya; Masayasu Koyama; Chihiro Azuma; Fumitaka Saji; Yuji Murata