Biomedical subjects

Yasushi Yagi

Publications and source records attributed to Yasushi Yagi.

7 recordsLinked to original sources

PubMed2005

Iconic memory-based omnidirectional route panorama navigation.

A route navigation method for a mobile robot with an omnidirectional image sensor is described. The route is memorized from a series of consecutive omnidirectional images of the horizon when the robot moves to its goal. While the robot is navigating to the goal point, input is matched against the memorized spatio-temporal route pattern by using dual active contour models and the exact robot position and orientation is estimated from the converged shape of the active contour models.

Algorithms↗

PubMed2005

EIPL (extensive intraoperative peritoneal lavage) therapy significantly reduces peritoneal recurrence after pancreatectomy in patients with pancreatic cancer.

One standing problem in the therapy for pancreatic cancer is peritoneal recurrence after pancreatectomy. We have established EIPL (extensive intra-operative peritoneal lavage) therapy as a very simple and non-aggressive prophylactic treatment for peritoneal dissemination of gastric cancer patients with peritoneal free cancer cells. In this study, the impact of EIPL therapy in preventing peritoneal recurrence in patients with pancreatic cancer after a curative surgical operation is analyzed. This study was based on 39 consecutive patients with invasive ductal adenocarcinoma of the pancreas who underwent curative surgical treatment. The patients were divided into two groups: the non-EIPL group, patients without EIPL therapy (from 1995 to 2000) (n=24); and the EIPL group, patients with EIPL therapy (from 2001 to 2003) (n=15). Clinicopathological findings, recurrence patterns and cancer-free survival were compared between the two groups. In addition, to identify free cancer cells during the operation, both carcinoembryonic antigen (CEA)- and cytokeratin 20 (CK20)-specific intraoperative real-time RT-PCR was performed immediately after laparotomy, lymph node dissection and removal of the pancreas in six patients with curative pancreatic cancer. Peritoneal, hepatic, lymphatic, local, and extra-abdominal recurrence rates in the EIPL and non-EIPL groups were 6.7, 40.0, 26.7, 13.3 and 13.3%, and 45.8, 50.0, 20.8, 29.2 and 20.8%, respectively. Among these recurrence patterns, the peritoneal recurrence rate of the EIPL group was significantly lower than that of the non-EIPL (P=0.013). Real-time RT-PCR analysis identified intra-peritoneal free cancer cells in 0, 33 and 67% of patients immediately after laparotomy, lymph node dissection and removal of the pancreatic cancer, respectively. After EIPL therapy, however, no cancer cell was detected in the peritoneal cavity. EIPL therapy was the independent negative risk factor for peritoneal recurrence (P=0.044), and the cancer-free 2-year survival of the EIPL group showed improvement compared with that of the non-EIPL group and was near statistical significance (P=0.097). EIPL therapy significantly prevented peritoneal recurrence after curative operation of pancreatic cancer, and it may contribute to reducing the mortality rate of this aggressive disease. Continued investigation of this promising treatment regimen is warranted.

Aged↗

PubMed2003

Mechanisms of peritoneal metastasis after operation for non-serosa-invasive gastric carcinoma: an ultrarapid detection system for intraperitoneal free cancer cells and a prophylactic strategy for peritoneal metastasis.

PURPOSE: This aims of this study are to establish an ultra-rapid quantitative reverse transcription-PCR (RT-PCR) protocol that enables the diagnosis of i.p. cancer spread during operation, to reveal the mechanisms of peritoneal metastasis from non-serosa-invasive gastric carcinoma, and to evaluate the effect of the extensive intraoperative peritoneal lavage (EIPL) using the ultra-rapid quantitative RT-PCR as a prophylactic strategy for peritoneal metastasis. EXPERIMENTAL DESIGN: Peritoneal lavage samples from 63 patients with non-serosa-invasive gastric carcinoma were obtained at laparotomy and immediately after lymph node dissection. To identify the free cancer cells in the samples, carcinoembryonic antigen- and cytokeratin 20-specific RT-PCRs were performed using the LightCycler method in combination with an automated mRNA extractor. In addition, EIPL was performed in five cases with serosa-invasive gastric carcinoma, and its efficacy was evaluated by the ultra-rapid quantitative RT-PCR protocol. RESULTS: The method enabled us to complete the detection of cancer cells within approximately 70 min. Both the carcinoembryonic antigen and cytokeratin 20 mRNA in i.p. lavages after lymph node dissection were identified in three (14.3%), four (26.7%), and six (46.2%) patients with submucosal, muscularis propria, and subserosal tumors, respectively. Lymph node metastasis was the independent predictor of the existence of i.p. free cancer cells. The ultra-rapid quantitative RT-PCR demonstrated that EIPL reduced free cancer cells from 3.8 x 10(5) +/- 1.4 x 10(5) cells to 2.8 +/- 1.5 cells/100 ml lavage after six to eight washes, and they disappeared after seventh to ninth wash. CONCLUSIONS: The present study proved that lymph node dissection opened lymphatic channels and spread viable cancer cells into the peritoneal cavity. It is suggested that the combination of the novel detection system with the intraoperative therapy of EIPL can be a useful prophylactic strategy for peritoneal metastasis from gastric carcinoma.

Aged↗

PubMed2002

BGP expression in gastric biopsies may predict the development of new lesions after local treatment for early gastric cancer.

BACKGROUND: Our previous studies have demonstrated the significant role of the generative cells of intestinal metaplasia (IM) expressing brain (fetal)-type glycogen phosphorylase (BGP) (BGP-IM) as a premalignant lesion of intestinal-type adenocarcinoma. The aims of the present study were to investigate the incidence of BGP-IM in gastric biopsy specimens and to establish BGP-IM as a predictor of the coexistence of accessory carcinoma and/or metachronous cancers before and after local treatment for early gastric carcinoma. METHODS: We studied the incidence of BGP-IM in eight endoscopic biopsy specimens of methylene blue-positive mucosa of the stomach obtained from patients with multiple gastric carcinomas (n = 14), a single carcinoma (n = 25), and atrophic gastritis (n = 20). RESULTS: BGP positivity was 93.3% in the multiple carcinomas and 80.0% in the single carcinomas. The incidences of BGP-IM (mean percentage +/- SD) in the stomachs with multiple carcinomas, single carcinoma, and atrophic gastritis were 83.2% +/- 22.8%, 36.5% +/- 41.3%, and 7.1% +/- 18.0%, respectively. The incidence was significantly higher in the stomachs with multiple carcinomas than in those with a single carcinoma or those with atrophic gastritis (P < 0.001). CONCLUSION: It is suggested that the frequent appearance of BGP-IM reflects the high potential of carcinogenesis of intestinal-type gastric cancer, and that the involvement of BGP-IM in more than 50% of the eight biopsies may be a predictor of the coexistence of accessory and/or metachronous carcinoma before and after local treatment for early gastric carcinoma.

Aged↗

PubMed2002

Extensive intraoperative peritoneal lavage and chemotherapy for gastric cancer patients with peritoneal free cancer cells.

The effects of extensive intraoperative peritoneal lavage (EIPL) for gastric cancer patients with peritoneal free cancer cells were investigated. This study was based on 22 consecutive patients with peritoneal free cancer cells, among 663 patients who underwent curative surgical treatment for advanced gastric cancer. The 22 patients were followed up for 2 years or until death. These patients were divided into three groups: group 1, patients with no additional intraoperative therapy (from 1989 to 1992; n = 8); group 2, patients with intraoperative intraperitoneal chemotherapy alone (from 1992 to 1995; n = 7); and group 3, patients with EIPL followed by intraoperative intraperitoneal chemotherapy (from 1996 to 1999; n = 7). Reverse transcriptase-polymerase chain reaction (RT-PCR) analysis showed that viable cancer cells were not detected after the eighth EIPL in a gastric cancer patient with numerous intraperitoneal free cancer cells. In group 3, 4 of the 7 patients survived for more than 2 years, including 3 with cancer-free status, whereas no patient survived cancer-free in groups 1 and 2. The peritoneal recurrence rates and cancer-specific 2-year survival rates in groups 1, 2, and 3 were 100%, 85.7% and 42.9%; and 0%, 14.3%, and 57.1%, respectively. The 2-year survival rate of group 3 was significantly higher than that of group 1 (P = 0.017) and that of group 2 (P = 0.025). In a subset analysis, patients with peritoneal free gastric cancer cells but no macroscopic dissemination showed a statistically significant improvement in survival those treated with EIPL compared with those not treated with EIPL.

Antineoplastic Agents↗

PubMedDate not supplied

Outpatient therapy with irinotecan and low-dose cisplatin for metastatic colorectal cancer resistant to 5-fluorouracil.

Chemotherapy with irinotecan hydrochloride and low-dose cisplatin was tested for the treatment of metastatic colorectal cancer showing resistance to 5-fluorouracil. Eleven consecutive patients with advanced metastatic colorectal cancer (performance status: 0 to 2), who had shown tumor progression on chemotherapy with 5-fluorouracil/leucovorin, were treated with irinotecan (60 mg/m2) plus cisplatin (6 mg/m2) by 90-min intravenous infusion. Treatment was repeated weekly for 3 weeks during admission and then fortnightly on an outpatient basis. Objective responses were observed in four patients (36%; 95% confidence interval: 11%-69%). The median duration of response was 5.5 months and six patients are still alive. The time to disease progression was longer in the no change group (7.0+/-3.6 months: mean +/- SD) than in the responder group (5.5+/-1.9 months), and there was no difference of median survival between the two groups (10.0 versus 10.3 months). The overall median survival was 8.2 months (range: 4 to 12+ months). This treatment was well tolerated. Six patients experienced grade 1 or 2 leucopenia, while grade I diarrhea and nausea occurred in three and five patients, respectively. Based on the good response, excellent quality of life, and convenience, the present regimen seems to be reasonable second-line outpatient chemotherapy for patients with metastatic colorectal cancer showing resistance to 5-fluorouracil.

Adenocarcinoma↗

PubMedDate not supplied

Second-line chemotherapy with combined irinotecan and low-dose cisplatin for patients with metastatic gastric carcinoma resistant to 5-fluorouracil.

Although 5-fluorouracil (5-FU) is still the mainstay of systemic treatment for patients with metastatic gastric cancer, many patients do not show satisfactory response to this drug. We treated patients with metastatic gastric cancer resistant to 5-FU with a combination of irinotecan hydrochloride (I) and low-dose cisplatin (P). Twenty-one consecutive patients with advanced metastatic gastric cancer and performance status of 0-2, who had received prior chemotherapy with S-1, but had nonetheless shown unrelenting tumor progression, were treated with 60 mg/m(2) of I combined with 6 mg/m(2) of P, administered by intravenous infusion over 90 min following premedication with azasetron (I/low-P). I/low-P was repeated weekly for 3 weeks with the patient admitted to hospital, and thereafter, fortnightly on an outpatient basis. Seven, eight and six of the total of 21 patients had liver metastases, lymph node metastases and peritoneal dissemination, respectively. Objective response was observed in 11 of the 21 patients (52%; 95% confidence interval: 31-78%). Two (18%) and nine (82%) of these 11 patients exhibited complete and partial response, respectively. The median duration of the response was 7.9 months. The treatment regimen under study was tolerated very well by the patients. Thirteen of the 21 patients (62%) developed grade 1 or 2 leucopenia, which was the most common adverse reaction recorded. Diarrhea and nausea, grade I in all of the cases, occurred in five (22%) and nine (43%) patients, respectively. Based on its remarkable effectiveness, marked improvement in the quality of life of the patients, and the convenience of its administration, the I/low-P regimen is recommended as a promising second-line chemotherapeutic regimen for patients with metastatic gastric cancer resistant to 5-FU.

Adult↗