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Biomedical subjects

H Takao

Publications and source records attributed to H Takao.

At least 37 records · Page 2Linked to original sources

The development of a dummy head for 3-D audiovisual recording for transmitting telepresence.

Manufacturing systems that employ modern technology often deprive workers of their humanity. One such example is seen in teleconferencing between remote plants. Here, it is difficult for participants to make eye-to-eye contact, a major obstacle in the communication of the participants; intentions and emotions. Indeed participants often complain that the facial expressions or emotions of the other side are difficult to perceive, that it is difficult to carry on a friendly, warm conversation, or that it is difficult to convey one's intentions to the other. They thus tend to become irritated during these conferences, and at times make erroneous judgements. In such situations, it can be said that the system users are being deprived of their humanity. This occurs because a machine or computer, when placed between two people communicating, interferes with a natural communication. What measures are there then to achieve a natural communication in such a setting, with a machine or computer between those communicating? These methods are classified here. In this study, a system for communicating 'presence' was employed to achieve a natural communication. The prototype system is call a 'dummy head for 3-D audiovisual recording'. Using this dummy head, dialogue between operators, remote control, as well as the recording of a skilled worker's use of his hands were carried out, and the results were evaluated. From these results, the authors report on how the prototype system, when placed between humans, helps to achieve a natural communication. Finally, some examples are given to show the human need for achieving a natural communication in such interface situations.

Communication↗

Palliative therapy using polyurethane-covered self-expandable metallic stents for malignant esophageal strictures: experiences in six patients.

To evaluate the utility and limitations of palliative stenting with polyurethane-covered self-expandable metallic stents, 6 patients (3 males and 3 females ranging in age from 58-85 [mean 72.1] years) with malignant esophageal strictures were treated with these stents between April 1993 and October 1995. Three had esophageal carcinoma, two had gastric carcinoma and one had lung carcinoma. Song-type self-expandable metallic stents were inserted by intubation under local laryngeal anesthesia. A retriever was attached in 4 stents and an anti-reflux mechanism was attached in 2 stents placed over the esophagocardiac strictures. The stents were placed successfully in all patients, and no major complication related to intubation was encountered. All the stents fully expanded within 3 days after insertion. The grade of dysphagia was improved in 5 (83%) of the 6 patients. One stent was extracted using a retriever in one patient with no improvement. No reflux symptoms were observed in 2 patients whom received stents with an anti-reflux mechanism. No blockage of the stent due to food impaction or secondary stricture occurred in any patient during the observation period. One stent migrated into the stomach in one patient 27 days after insertion. Esophageal stenting with polyurethane-covered self-expandable metallic stents is a relatively safe and effective palliation for malignant esophageal strictures.

Aged↗

[Locoregional therapy for liver metastases of colorectal cancer].

The role of biological response modifiers (BRM) in locoregional therapy for liver metastases of colorectal cancer was studied clinically and experimentally. Seven patients with numerous metastases to both lobes of liver were given intraarterial administration of BRM in combination with anticancer drugs. A partial response was observed in 1 patient. The response rate was 14.3%. Alternatively, intraarterial administration of both OK-432 and IL-2 into the rabbit with liver metastases of VX-2 tumors could bring about the infiltration of cytotoxic T lymphocytes around the tumors, followed by a significant decrease of the metastatic nodules. In addition, the same anti-tumor effect was observed when PSK was administered intraperitoneally into the BALB/c mouse with liver metastases of colon 26 tumors. Moreover, the therapeutic effect of water in oil type emulsion encapsulating both OK-432 and IL-2 was greater than that of the solution of BRM in BALB/c mouse with liver metastases of colon 26 tumors. These results indicated that BRM could be one of the promising agents in locoregional therapy against liver metastases of colorectal cancer.

Adult↗

[A new modality of locoregional chemotherapy based on biochemical double modulation of 5-fluorouracil with both leucovorin and cisplatin against liver metastases of colorectal cancer].

A new modality of locoregional chemotherapy based on biochemical double modulation of 5-fluorouracil (FU) with both leucovorin (LV) and cisplatin (CDDP) against liver metastases of colorectal cancer was devised. The schedule for the locoregional therapy was as follows; bolus infusion of LV (6 mg/body) followed by 30-minute infusion of CDDP (10 mg/body) and 30-minute infusion of 5-FU (250 mg/body). Four colorectal cancer patients with numerous metastases to both lobes of liver were given intraarterial administration of above anticancer drugs every 1-2 weeks after resection of primary lesions. On the one hand, 3 colorectal cancer patients, who developed a few metastases to both lobes of liver, were treated preventively by the same schedule every 2-3 weeks after the resection of metastatic tumors. As for the clinical (radiographic) response, complete response and partial response were observed in 1 and 2 of 4 patients, respectively. The response rate was 75%. No new lesions appeared for over 1 year by the preventive treatment in 2 of 3 patients, whereas new lesions appeared in one patient at 3 months after discontinuation of treatment because of mild toxicity. The toxicity, however, was within acceptable limits. These results indicated that biochemical double modulation of 5-FU with both LV and CDDP is a very promising locoregional chemotherapy against liver metastases of colorectal cancer.

Aged↗

[Immunological effects of locoregional immunochemotherapy for liver metastases of gastric cancer].

Nine gastric cancer patients with simultaneous liver metastases were given intermittent transarterial administration of chemotherapeutics (adriamycin, mitomycin C or 5-fluorouracil) and biological response modifiers (BRM; OK-432 and interleukin (IL) -2) after gastrectomy. In terms of direct antitumor effect on liver metastases, a partial response was observed in 4 of 9 cases (44%). In addition, the concentration of 3 kinds of cytokines such as IL-6, tumor necrosis factor (TNF) -alpha and interferon (IFN) -gamma in the peripheral blood sera was measured immediately before and after transarterial administration of agents. While the concentration of IL-6 increased by BRM, chemotherapeutics could not alter the level of IL-6. As for TNF-alpha and IFN-gamma, no particular changing pattern was observed after transarterial administration. Furthermore, natural killer (NK) activity of peripheral blood mononuclear cells was measured. Administration of either BRM or BRM in combination with chemotherapeutics caused a decrease in NK activity, whereas chemotherapeutics did not. Flow cytometric analysis using 3 kinds of monoclonal antibodies (Anti-CD16, CD56 and CD57) revealed that the proportion of subset of both highly activated NK cells (CD16+.CD56+.CD57-) and moderately activated NK cells (CD16+.CD56+.CD57+) reduced after administration of BRM.

Antineoplastic Combined Chemotherapy Protocols↗

[Significance of antitumor effects and immunological response on endogenously induced LAK therapy for primary or metastatic liver tumor].

Nineteen patients with metastatic liver tumor (9 of gastric cancer, 5 of colon cancer, 2 of pancreatic cancer, one each of mammary cancer, cholecystic cancer, carcinoid of biliary tract) and one patient with primary liver cancer were treated by endogenously induced LAK therapy consisting of transhepatic arterial infusion with ADM or MMC for induction therapy and OK-432 and rIL-2 (TGP-3) for immunotherapy. The following results were obtained. 1) Clinical response for liver tumor showed no CR but 8 cases of PR, for an overall response rate of 42.1%. 2) Reduced tumor marker value was noted in 76.5% cases, and 50% survival term became 349 days after the therapy. 3) Many CD4 and CD8 positive mononuclear cells had infiltrated around liver tumor after therapy by immuno-histochemical staining of surface marker. 4) NK activity of peripheral blood lymphocytes was markedly reduced soon after the therapy and continued for about 4-7 days, while in cases of combined subcutaneous administration with OK-432, NK activity showed only a slight decrease.

Antineoplastic Combined Chemotherapy Protocols↗

[Clinical studies on locoregional immunochemotherapy of peritonitis carcinomatosa].

Although 58 patients with peritonitis carcinomatosa underwent multidisciplinary therapy over the last 5 years in our department, about half of them died within 3 months after treatment. In addition, the prognosis was poor for gastric and colon cancer patients, who had macroscopic peritoneal dissemination. Therefore intraoperative intraperitoneal administration of either BRM or anticancer drugs was performed for the microscopic peritoneal dissemination of the cancer, and the immunological response in the peritoneal cavity was examined. In terms of subpopulation of peritoneal exudate cells, neutrophil leucocytes were predominant and thereafter lymphocytes increased. As for the cytokines in the exudate from peritoneal cavity, the concentration of interleukin-6 peaked within 24 hours after administration, followed by a gradual decrease, while the concentration of interferon-gamma was detectable at more than 24 hours after operation, followed by a gradual increase. Tumor necrosis factor-alpha was also detectable in the exudate. Its concentration decreased when both OK-432 and MMC were administered, but it increased when CDDP was administered. The above results indicated that preventive intraoperative intraperitoneal administration of BRM and anticancer drugs should bring about individual immunokinetic modulation in tumor bearing host and both cytokines and immunocytes could play an important role in locoregional tumor immunity.

Cisplatin↗

Leiomyosarcoma of the duodenum.

Leiomyosarcoma of the duodenum is a rare disease and its characteristics have been described previously in the literature. We present a case of duodenal leiomyosarcoma, which was diagnosed by several imaging techniques prior to operation. Findings of computed tomography (CT), magnetic resonance imaging (MRI), ultrasonography, and angiography in this case are discussed.

Aged↗

[A long-term survival case of advanced gastric cancer undergoing radical gastrectomy by second-look operation after successful chemotherapy (CDDP, MMC, 5-FU)].

A 55-year-old woman with gastric cancer underwent laparotomy and was found to have an unresectable tumor characterized by S3 (invasion of the pancreas), N3, P0 and H0. She was then treated by combined administration of cisplatinum, mitomycin C and 5-fluorouracil. A remarkable response (CR) was confirmed by upper gastrointestinal roentgenography and endoscopy. Upon reoperation about 8 weeks after chemotherapy, a successful radical total gastrectomy with R2 (partially R3) lymphnode dissection was performed. Histological examination of the specimens, including the stomach and lymphnodes, revealed no cancer cells in any region (pCR). She had been given UFT and PSK for 4 years 4 months after reoperation. She has lived for 5 years 2 months after reoperation without any signs of recurrence or metastases.

Adenocarcinoma↗

[Therapeutic effect of transarterial infusion immunochemotherapy for metastatic liver cancer].

In order to improve therapeutic efficacy for metastatic liver cancer, intermittent transarterial administration of BRM in combination with anticancer drugs was performed by use of reservoir apparatus. A total of 22 patients (12 cases of gastric cancer, 6 of colon cancer, 2 of pancreas cancer, 1 of gall bladder cancer and 1 of biliary tract carcinoid) were treated according to the following schedule: both 10 mg of ADM (or MMC) and 0.5 KE (or 1.0 KE) of OK-432 were administered on day 1 and 40 x 10(4) JRU of recombinant interleukin 2 (r-IL 2) on day 4, 7 and 11. The treatment was repeated as many times as possible. In terms of direct antitumor effect and decrease of tumor marker, the response rate was 43% (6 cases out of 14) and 75% (9 cases out of 12), respectively. As for performance status, improvement, no change and deterioration were seen in 4 cases, 8 cases and 3 cases, respectively. Even though 13 patients died, 8 of them survived more than 300 days. In the case of gastric cancer patients with liver metastasis, 50% survival time of 12 cases was 334 days, while that of 30 cases, who were administered anticancer drugs only systemically, was 144 days. In 3 cases the decrease in the size of tumors located in both liver and the other metastases also was seen. Every case developed high grade fever, but an antifebrile was effective. Otherwise severe side effects were not seen. These results indicated that intermittent arterial infusion immunochemotherapy was feasible for the treatment of metastatic liver cancer.

Antineoplastic Combined Chemotherapy Protocols↗

[Intraoperative intraperitoneal administration of mitomycin C and OK-432 for peritoneal dissemination of gastric cancer].

In order to improve the prognosis, intraoperative intraperitoneal administration of both mitomycin C and OK-432 was performed for the peritoneal dissemination of gastric cancer. Some 74 of 469 patients of gastric cancer, who underwent surgical treatment over the last 7 years in our department, had peritoneal dissemination and 24 of them were treated with the drugs described above. However, there was no significant difference between treated group and controlled untreated group. No severe side effects were noted except for moderate pyrexia. It is still too early to determine the effect of this treatment because of both the short duration of follow-up and the small number of analyzed cases. In the future, we are planning to apply this treatment to selected cases, for which a histological diagnosis will be made intraoperatively by use of irrigation cytology and/or stamp biopsy.

Adult↗

[Asynchronus rejection of intrathoracic heart-lung transplantation rats].

We have reported intrathoracic heart-lung transplantation in rats could be made easily by using Internal Shunt Method as described elsewhere. In this study, we examined the rejection of intrathoracic heart-lung allografts in this model to determine whether acute pulmonary rejection precedes cardiac rejection following heart-lung transplantation or not. Ten heart-lung allografts (no immunosuppressive agent was given) and four isografts were examined pathologically. There was no pathologic change except perivascular or peribronchiolar edema in isografts, which was attributed to operative damage. Acute pulmonary rejection apparent pathologically 3 days after transplantation and lung allografts lost its function 6 days after transplantation. Otherwise, acute cardiac rejection first became apparent pathologically 5 days after transplantation. And their pulsation appeared well 6 days after it. It is concluded that pulmonary rejection precedes cardiac rejection following heart-lung transplantation.

Animals↗

[In vivo antitumor effect of LAK cells induced from various lymphocytes--experimental study in rats].

A MRMT-1 was inoculated in the thigh of SD rats. On day 7, regional lymph node lymphocytes (TB-LN), thymus cells (TB-TC) and spleen cells (TB-SC) or non-tumor bearing spleen cells (NB-SC), were obtained. LAK were induced with lug/ml of R-IL2 (TGP-3) using above lymphocytes, and were examined as for their in vivo and in vitro cytotoxic activities. In vitro: Against MRMT-1, cytotoxic activity of LAK increased with lapse of culturing time. Thus on day 4 of culture, it was the highest (46.5%) in TB-SC-LAK, while that of TB-LN-LAK was the lowest (5.8%). Against YAC-1, they also increased except TB-LN-LAK. In vivo: When the mixture of MRMT-1 and LAK was sc inoculation, diameter of the tumor were the smallest in TB-LN-LAK and the largest in TB-SC-LAK. When it was injected intraperitoneally, in non-irradiated rats, the survival prolongation was the best in TB-LN-LAK and the worst in TB-SC-LAK. In pre-irradiated rats; the cytotoxicity was almost the same as the results of in vitro. When it was injected intravenously, number of lung metastatic nodes were the smallest in TB-LN-LAK and the largest in TB-SC-LAK. R-IL2 substitution therapy was also effective. In conclusion, the effectiveness of LAK-AIT was estimated more accurately by in vivo cytotoxic assay. TB-LN was most useful as a source of LAK cells.

Animals↗

[Experimental study on preventive effects of lung metastases using LAK cells induced from various lymphocytes--special references to enhancement of lung metastasis after laparotomy stress].

In 5 week-old female SD rats, ether anesthesia or laparotomy for 30 minutes was done, followed by iv inoculation of 1 x 10(6) MRMT-1 cells. On day 14, number of lung metastatic nodules was examined. Preventive effect of LAK cells on lung metastases was also observed. LAK cells were induced from regional lymph node lymphocytes (LN), thymus cells (TC) and spleen cells (SC) of the rats on day 7 after tumor inoculation by incubation with 1 micrograms/ml of R-IL2 (TGP-3) for 4 days. 1) Lung metastases were noted in 100% after MRMT-1 intravenous inoculation, while number of lung metastatic nodules was reduced after iv administration of LAK cells. 2) When MRMT-1 cells were inoculated intravenously after laparotomy stress for 30 minutes, number of lung metastatic nodules was significantly increased and LAK cells reduced it significantly. 3) When R-IL2 sc administration for 4 days was accompanied, number of lung metastatic nodules was less than that of without R-IL2 substitution. 4) The antitumor effect of LAK cells was the strongest in LN-LAK, while it was the weakest in SC-LAK. In conclusion, usefulness of LAK cells for preventing lung metastases by surgical stress was indicated. This fact suggested that possibility of adoptive immunotherapy using LAK cells might be useful for prevention of lung metastases after laparotomy.

Animals↗

[Effects of serum immunosuppressive factors on the cytotoxicity of lymphokine-activated killer (LAK) cells induced by recombinant interleukin 2(R-IL2)].

Fundamental studies were performed on adoptive immunotherapy, especially on effects on lymphocytic cytotoxic activity, of nonspecific immunosuppressive factors (ferritin, IAP, AFP) and of serum factors obtained from gastric cancer patients, and possible intervention of suppressor T cells in serum immunosuppressive activity on the cytotoxicity was also examined. The following results were obtained. 1) Cytotoxicity of LAK cells induced by culturing normal peripheral blood lymphocytes (PBL) with R-IL2 in the medium containing normal AB-type sera, was higher than that of PBL. 2) Effect of nonspecific immunosuppressive factors on cytotoxicity of LAK cells was lower than that on cytotoxicity of PBL. 3) Cytotoxicity of PBL was inhibited in a relatively specific fashion by sera from patients of the cancers which were of identical histological types with the target tumor cells, while that of LAK cells was hardly inhibited by patients' sera. 4) Cytotoxicity of Leu 15-PBL was inhibited by nonspecific immunosuppressive factors and also by cancer patients' sera in a relatively specific fashion in relation to histology. 5) Cytotoxicity of Leu 15-LAK cells was hardly inhibited by serum nonspecific and specific immunosuppressive factors. The above results showed that serum immunosuppressive factors might act on PBL cytotoxicity without intervention of suppressor T cells, and that LAK cells were hardly inhibited by such immunosuppressive factors. All these results suggested usefulness of adoptive immunotherapy with LAK.

Adult↗