PubMed Health⌕ Search

Biomedical subjects

M Saimura

Publications and source records attributed to M Saimura.

7 recordsLinked to original sources
PubMed2006

Peritumoral injection of adenovirus vector expressing NK4 combined with gemcitabine treatment suppresses growth and metastasis of human pancreatic cancer cells implanted orthotopically in nude mice and prolongs survival.

NK4 or adenovirus vector expressing NK4 (Ad-NK4) can act bifunctionally as a hepatocyte growth factor antagonist and angiogenesis inhibitor and has potential value in cancer therapy. The aim of this study was to evaluate the therapeutic efficacy of Ad-NK4 in combination with gemcitabine (GEM) against pancreatic cancer. In vitro study showed a strong antiproliferative effect of GEM and a potent anti-invasive effect of Ad-NK4 against pancreatic cancer cells. In in vivo experiments, SUIT-2 human pancreatic cancer cells were implanted into the pancreas of nude mice. Mice were treated with Ad-NK4 by injection into the peritumoral region of the pancreas on day 5 after implantation followed by weekly i.p. injections of GEM. On day 28 after implantation, pancreatic tumor volume was significantly smaller than that in mice treated with Ad-LacZ, Ad-NK4 alone, or GEM alone. Furthermore, combination therapy completely suppressed peritoneal dissemination and liver metastases, leading to significantly increased survival. Histologic and immunohistochemical assays of primary tumors indicated that combination therapy prohibited both cell proliferation and angiogenesis, resulting in high levels of apoptosis. These results suggest that peritumoral injection of Ad-NK4 plus GEM is a potent combination therapy for pancreatic cancer.

Adenoviridae↗
PubMed2001

Effect of serum depletion on centrosome overduplication and death of human pancreatic cancer cells after exposure to radiation.

The tumor microenvironment is one of the key factors affecting the cellular response to radiation; however, the influence of serum concentration on tumor radiosensitivity remains poorly understood. We recently discovered that gamma-irradiation of tumor cells causes centrosome overduplication, which may lead to lethal nuclear fragmentation through the establishment of multipolar mitotic spindles. In the present study, we investigated the effect of serum depletion on radiation-induced cell death in relation to the centrosome dynamics in human pancreatic cancer cells. Exposure of Capan-1 cells to gamma-irradiation resulted in a time-dependent increase in cells containing multiple centrosomes in association with the appearance of mitotic cell death. Treatment of irradiated cells with serum depletion drastically accelerated centrosome overduplication and the formation of multipolar spindles, resulting in increased nuclear fragmentation and cell death. Cell cycle analysis of irradiated cultures revealed that the reduced serum level increased the population of cells arrested in the G2/M phase, which might be responsible for the abnormal centrosome accumulation. These findings suggest that serum concentration can influence radiation-induced cell killing through modulating cell cycle progression and possibly centrosome overduplication.

Cell Death↗
PubMed1999

Breast Carcinoma with Osteoclast-like Giant Cells: A Case Report and Review of the Japanese Literature.

A 41-year-old premenopausal woman with a 3.5 cm freely mobile mass in the upper outer quadrant of the right breast was admitted to our hospital. Fine needle aspiration showed malignant epithelial cells and many multinucleated osteoclast-like giant cells (OGCs). Excisional biopsy revealed an invasive ductal carcinoma. A right modified radical mastectomy was subsequently performed. Macroscopically the tumor was well circumscribed with a dark brown cut surface. Microscopically, the tumor was a grade 2 invasive ductal carcinoma with many multinucleated OGCs adjacent the tumor cells and hemorrhage and infiltration of inflammatory cells in the stroma. The intra-mammary metastasis also contained OGCs and stromal reactions. By enzyme immunoassay, the tumor cells were negative for estrogen receptor but positive for progesterone receptor. The tumor cells were negative for both c-erbB-2 and p53. The OGCs showed positive immunostaining with the monoclonalantibody CD68, demonstrating a histiocytic origin. Lymph nodes were free of metastasis. We also review the Japanese literature concerning breast carcinoma withOGCs.

Journal Article↗
PubMed1999

Prognosis of a series of 763 consecutive node-negative invasive breast cancer patients without adjuvant therapy: analysis of clinicopathological prognostic factor.

BACKGROUND AND OBJECTIVES: The objectives of this study were to confirm the favorable outcome of Japanese invasive breast cancer patients without lymph node metastasis, after treatment with surgery alone, and to evaluate clinicopathological prognostic factors in this population. METHODS: The subjects were 763 consecutive node-negative invasive breast cancer patients who underwent surgery without adjuvant therapies between 1988 and 1993 at our hospital. Disease-free survival (DFS) and overall survival (OS) rates were analyzed by clinicopathological factors. RESULTS: The median age of the patients at surgery was 52 years and the median follow-up period of patients was 74 months. At 5 years, the respective DFS and OS rates of all patients were 90.8% and 93.9%. Patients with a pathological tumor size of invasive component of more than 2 cm (319 patients) had a significantly lower DFS than those with tumors measuring 2 cm or less (361 patients) (P = 0.045). Patients with positive hormone receptor status (280 patients) (estrogen and/or progesterone receptor positive) tended to have a better OS than those negative for both hormone receptors (92 patients) (P = 0.078). Meanwhile, patients with tumors of histological grade 3 (328 patients) had a much poorer prognosis than those with tumors of histological grade 1 or 2 (413 patients) (P = 0.008 for OS and P = 0.042 for DFS). The respective 5-year DFS and OS rates of patients with histological grade 3 tumors larger than 2 cm in pathological tumor size of invasive component (195 patients) were 85.5% and 87.6%, indicating that these node-negative patients form a high risk group. CONCLUSIONS: Japanese invasive breast cancer patients without lymph node metastasis tended to show a survival advantage compared with their Caucasian counterparts. Histological grade was the most useful prognostic factor in this population.

Adult↗
PubMed1998

Secretory carcinoma of the breast in an elderly woman: report of a case.

We herein report a case of secretory carcinoma of the breast in a 73-year-old woman. Secretory carcinoma is an extremely rare tumor and demonstrates distinctive pathologic characteristics. This tumor frequently occurs in either children or adolescents, and thus has been called juvenile carcinoma. We encountered this rare tumor in an elderly woman. Aspiration biopsy cytology was performed twice, but the cytological diagnosis was not carcinoma. Such pathologic characteristics as mild atypia, the absence of hyperchromasia, and a minimal degree of pleomorphism in the tumor cells can thus lead to a cytological misdiagnosis. An excisional biopsy was performed and secretory carcinoma was finally diagnosed. Consequently, a modified radical mastectomy (Kodama's method) was performed 7 days later. We describe this very rare tumor's clinicopathologic characteristics.

Age Factors↗
PubMed1996

Multiseptate gallbladder: biliary manometry and scintigraphy.

A 30-year-old man with multiseptate gallbladder, a very rare congenital anomaly, is presented. His presenting symptom was epigastric pain. A hypoplastic gallbladder with multiple septa was demonstrated by ultrasonography and endoscopic retrograde cholangiography. An injection of cerulein reproduced pain, and simultaneous biliary manometry and scintigraphy showed impairment of gallbladder filling and emptying. Laparoscopic cholecystectomy resulted in complete relief of the pain. Biliary manometry and scintigraphy are useful to determine the operative indication in a symptomatic patient with this entity.

Adult↗