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Autonomous robots need to learn the categories of various places by exploring their environments and interacting with users. However, preparing training datasets with linguistic instructions from users is time-consuming and labor-intensive. Moreover, effective exploration is essential for appropriate concept formation and rapid environmental coverage. To address this issue, we propose an active inference method, referred to as spatial concept formation with information gain-based active exploration (SpCoAE) that combines sequential Bayesian inference using particle filters and information gain-based destination determination in a probabilistic generative model. This study interprets the robot's action as a selection of destinations to ask the user, `What kind of place is this?' in the context of active inference. This study provides insights into the technical aspects of the proposed method, including active perception and exploration by the robot, and how the method can enable mobile robots to learn spatial concepts through active exploration. Our experiment demonstrated the effectiveness of the SpCoAE in efficiently determining a destination for learning appropriate spatial concepts in home environments., Accepted to Advanced Robotics

Relations of nm23 expression to 8 clinicopathologic variables and proliferative activity of cancer cells were examined in 22 patients with early gastric cancer, to clarify the role of nm23 in the cancer lesions. The expression in cancer lesions was immunohistochemically analyzed, and the proliferative activity was evaluated by proliferating cell nuclear antigen (PCNA) labeling index (LI). Expression of nm23 was found in 11 lesions (positive group) but not in 11 lesions (negative group). A significant (P

Carcinoembryonic antigen (CEA) producing tumor, MKN45, cells were transplanted into 15 nude mice, and the mutual relations of serum CEA levels to tumor volume and proliferative activity of tumor cells were analyzed. The proliferative activity was evaluated by proliferating cell nuclear antigen (PCNA) labeling index (LI, %). Respective 2 or 3 mice were sacrificed 1, 2, 3, 4, 5, 6 and 7 weeks after transplantation under etherization. Transplanted tumors grew semi-logarithmically during the experimental period. Correlations represented by the formulas, Y (CEA, ng/ml)=0.002X (tumor volume, mm^3)+1.515 (r=0.745, P

Plasma diamine oxidase (DAO) activity after heparin injection, a circulatory marker for the intestinal mucosal integrity, was evaluated shortly after major abdominal surgery. DAO activity was measured by high-performance liquid chromatography method after 50 units/kg of heparin injection after esophagectomy in 8 patients, total gastrectomy in 16 patients, and pancreatectomy in 7 patients. Blood samples were collected before and at 2, 10, and 30 days after operation. Postheparin DAO activity at the 2nd day after operation decreased to 60% of the value before operation (p

Chronological and clinicopathological changes of 196 colorectal cancer patients over 70 years of age (aged patients) were examined by comparing with those of 105 patients under 50 years of age (young patients) , to analyze the recent trends of colorectal cancer in Japan. The aged patients increased significantly in rate from 17.3% in the 1970's to 38.5% in the 1990's. Inversely, the young patients decreased from 25.2% in the 1970's to 6.6% in the 1990's. A significant difference between both patient-groups was found in only one, location of the cancer, out of 11 clinicopathological variables: rectal cancer in the aged patients was significantly more than in the young patients, while colon cancer in the former was significantly less than in the latter. From the results, rectal cancer may be concluded to increase recently in the aged and/or elderly people in Japan. Thus, periodical screening tests for rectal cancer may be necessary in these people, to prevent and detect the cancer as early as possible.

Postoperative survival of 196 colorectal patients over 70 years of age (aged group) was examined by comparing with that of 105 patients under 50 years of age (young group), and clinicopathologic variables between the groups were analyzed, to clarify the principles of prevention and early detection for the aged and/or elderly patients. Survival curve of the young group was not statistically different from that of the aged group, and the 5-year survival rate was 52.3% in the former and 49.6% in the latter. No significant difference between the groups was found in 10 out of 11 background variables strongly affecting survival. However, a significant difference (P

Relations of serum CEA levels to 13 Clinicopathologic variables of cancer lesions and proliferating cell nuclear antigen (PCNA) labeling indices (LIs) of cancer cells were examined in 57 colorectal center patients. Six variables including deep invasion into the colorectal wall, lymphatic and venous invasion, node metastasis, liver metastasis and advanced stages were more in 28 patients with positive CEA levels (≧5.0 ng/ml) than in 29 patients with negative CEA levels (

Relations of the proliferative activity of cancer cells to 13 clinicopathologic variables of cancer lesions and postoperative survival were examined in 57 colorectal cancer patients. The proliferative activity was determined by proliferating cell nuclear antigen (PCNA) labeling indices (LIs) in the primary cancer lesions, and the patients were classified into 2 groups by the mean (49.4 %) of PCNA LIs in all the lesions: 31 patients with high LIs over the mean (high PCNA group) and 26 patients with low LIs under the mean (low PCNA group). Three variables including deep cancer invasion, liver metastasis and advanced stages were significantly more frequently found in the high PCNA group than in the low PCNA group. However, no significant difference was found in the other 10 variables. Survival curve was significantly better in the low PCNA group than in the high PCNA group, and the 3 year-survival rate was 92.4 % in the former and 48.2 % in the latter. The results suggest that the proliferative activity of cancer cells in the primary lesions strongly affects the cancer progression and that the determination of proliferative activity representing by PCNA LIs of cancer cells is clinically useful for the evaluation of survival and/or prognosis in colorectal cancer patients.

The score of argyrophilic nocleolar organizer regions (AgNOR) was determined in 80 colorectal cancer patients, and the correlation between AgNOR score (dot number/nucleus) and survival was examined. The survival curve in 40 patients with low AgNOR score under the mean (3.81) of all the primary cancer lesions was significantly better than that in 40 patients with high AgNOR score over the mean, and the 4-year survival rate was 94% in the former and 71% in the latter. Significant differences between both patient-groups were found in 6 out of 11 background variables: deep cancer invasion, node and liver metastases, Dukes stage D, low grades of node dissection and curability C were significantly more in the patients with high AgNOR score than in the patients with low AgNOR score. These results suggest that the determination of AgNOR score in the cancer lesions is clinically used as a prognostic parameter in colorectal cancer but that the score is not an independent parameter from the clinicopathologic prognostic parameters.

The score of argyrophilic nucleolar organizer regions (AgNOR) was determined in 54 colorectal cancer lesions, and the relations of AgNOR score (dot number/nucleus) to 12 clinicopathologic variables and nuclear DNA ploidy pattern of the cancer lesions were examined. Significant differences of the AgNOR score were found in 7 variables: the mean scores were significantly higher in the lesions with large size (≧6.0 cm), deep cancer invasion of se (a2) ～ si (ai), positive node and liver metastases, high grages of lymphatic and venous invasion and Dukes C ～ D stages than in the lesions with small size (

A total of 104 gastric cancer patients underwent curability A resection was prospectively randomized and classified into 2 major groups, in order to clarify the efficacy of tegafur (FT) or tegafur-uracil (UFT) and/or mitomycin C (MMC) as adjuvant chemotherapy. Sixty-three patients in Groups 1A and IB received FT 600 mg/day and UFT 400 mg/day orally during the period over 12 months respectively. Forty-one patients in Groups 2A and 2B received a bolus injection of MMC 0.4 mg/Kg just after resection and the same doses and period of oral FT and UFT as Groups 1A and IB respectively. The disease-free curve in Group 1B was significantly (p

Postoperative survival of 299 gastric cancer patients over 70 years of age (aged group) was examined by comparing with that of 307 patients under 50 years of age (young group), and the clinicopathologic background-variables between both groups were analyzed. Survival curve of the aged group was significantly worse than that of the young group and the 5-year survival rate was 43.9% and 54.3% respectively. Althought no significance difference between the groups was found in the tumor size, node metastasis, invasive depth, lymphatic invasion, node dissection, curability and stage classification, five variables including cancer in the lower 3rd of the stomach, liver metastasis, macroscopic type 1～2, differentiated adenocarcinoma and venous invasion were significantly more in the aged group than in the young group . Reversely, peritoneal dissemination was significantly more in the latter than in the former. The results suggest that the intra- and/or post-operative therapies and prevention for liver metastases or recurrence in the aged group and for peritoneal dissemination or recurrence in the young group are important for the further improvement of survival.

A 91-year-old male with adenocarcinoma of the gallbladder found at the time of cholecystectomy for the lithiasis was reported. Preoperative examinations including ultrasonograpghy, computed tomograpy, cholecystography and tumor markers revealed actute cholecystitis due to the incarceration of cholelithiasis in the Hartmann's pouch and no evidence of adenocarcinoma, but an adenocarcinoma appearing as stage III was found at the time of cholecystectomy. The indication of cholecystectomy for the lithiasis has been discussed, because gallbladder carcinoma coexists occasionally with cholelithiasis in the aged patients and because it is very difficult to diagnose the carcinoma in the presence of cholelithiasis prior to cholecystectomy.

Relationship between survivals due to the difference of nuclear DNA ploidy patterns and prognostic factors was examined in 27 gastric cancer patients. The survival curve of 13 patients with diploid cancer was significantly better than that of 14 patients with aneuploid cancer, and the 9-year survival rate was 42.4% in the former and 21.4% in the latter. The mean (91.5‰) of mitotic index (MI) representing mitotic activity (MA) in the aneuploid cancers had a tendency to be higher than that (76.6‰) of the diploid cancers. The survival curve of 11 patients with low MA (MI≦80‰) was significantly better than that of 16 patients with high MA (MI>80‰), and the 9-year survival rates in the former and the latter were 53.0% and 10.7% respectively. Venous invasion out of 8 clinicopathologic prognostic factors was significantly higher in the aneuploid cancers than in the diploid cancers. These results suggest that determination of DNA ploidy is available for the estimation of prognosis in gastric cancer patients and that difference of survivals due to the ploidy patterns is caused by the difference of MA and venous invasion.

The suppresive effects of mitomycin C (MMC) on liver recurrence were examined by varying the injection doses and routes in 45 gastric cancer rabbits. The primary cancer lesions without metastasis were resected 14 days after implantation of VX2 cancer, and the animals were autopsied 14 days after resection. Liver recurrence was found in 90 % of control animals, but was not found in animals which received postoperative portal MMC 0.5 and 0.25 mg/Kg and peripheral MMC 1.0 mg/Kg injections. The recurrence rate was significantly higher in the control than in the MMC injected animals. The recurrence was found in 86 and 71% of animals which received postoperative portal MMC 0.125 mg/Kg and peripheral MMC 0.5 mg/Kg injections, respectively. No significant difference was found in the rates between the control and these MMC injected animals. These results suggest that portal MMC injection is more effective for the suppression of liver recurrence than the peripheral injection and that the efficacy dose of the former is almost the same as the 1/4 dose of the latter.

A rare case of superficial bladder cancer with a massive hemation after perineal blunt injury was reported. A 66-year-old male complained of lower abdominal pain and urinary retention about twelve hours after the injury. Following excretion of a large amount (1,060 ml) of hematuria through a transurethral catheter, hematuria became gradually bloody and the excretion frequently stopped in spite of the catheterization. Therefore, catheter vesicotomy was necessary for urine excretion, and 2,400 ml of the blood was transfused for the maintenance of vital signs during 8 days up to the surgical therapy. Morphologic examinations revealed a protrusive tumor into a massive hematoma in the bladder. At the time of operation, however, five tumors were found, and the bleeding point was certified to be the stalk of the biggest one. After removal of the tumors and 490 g of hematoma, his urination was uneventful. Microscopically, all the tumors were superficial transitional cell carcinomas. The pathogenesis concerning the acute onest of urinary retention with a massive hematoma is discussed.

Chronologic change and clinicopathology of 299 gastric cancer patients over 70 years of age (old group) were examined by comparing with those of 307 patients under 50 years of age (young group), and the histogenesis was discussed. The patients of the old group increased significantly in frequency from 9.9 % in the 1960's to 33.9 % in the 1990's, and the patients of the young group decreased clearly from 23.5 % in the 1960's to 9.4 % in the 1990's. However, no significant difference was found in the frequency of patients between 50 and 69 among 4 periods from the 1960's to the 1990's. In 6 out of 12 clinicopathologic factors, significant difference were found between both groups; male, tumor of lower 3rd of the stomach, macroscopic localized type in advanced cancer and protruded and elevated types in early cancer, liver metastasis, differntiated adenocarcinoma and venous invasion were significantly more in the old group than in the young group. From the results, it is suggested that the frequency of gastric cancer in Japan increases recently in the old group and decreases in the young group. Histogenetically, differentiated adenocarcinoma originating from intestinal metaplasia is suggested to arise more frequently in the former than in the latter.

Survivals due to the difference of DNA ploidy patterns were examined in 34 colorectal cancer patients, and the effects of prognostic variables including mitotic activity and clinicopathology of cancer lesions on the survivals were analyzed. The survival curve of 14 patients with diploid cancer was significantly better than that of 20 patients with aneuploid cancer, and the 9-year survival rate was 68.4 % in the former and 33.8 % in the latter. The mean (26.1 %o) of mitotic indices in the aneuploid cancers was significantly higher than that (18.7 %o) in the diploid cancers. Although no significant difference in 7 out of 9 clinocopathologic variables was found between both DNA ploidy patterns, node metastasis and advanced stages in the aneuploid cancers were significantly more than those in the diploid cancers. These results clearly indicate that the survival of patients with diploid cancer is better than that of patients with aneuploid cancer. Difference of the survivals between them seems to be caused by the difference of mitotic activity, node metastasis and stage classification.