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K Tamada

Publications and source records attributed to K Tamada.

At least 91 records · Page 5Linked to original sources
PubMed1996

A quantification of goldfish behavior by an image processing system.

We developed a computer-image processing system to quantitatively score the goldfish behavior. The system was composed of two CCD cameras, set in the upper and side directions of a water tank, two graphics I/O boards (video interface) and an IBM PC/AT compatible computer. From the top and side views through the two CCD cameras, 2-dimensional or 3-dimensional positional coordinates of fish freely moving in an aquarium were acquired over a long period (60 min). A positional distribution histogram of the goldfish was made by measuring the number of coordinates. Goldfish have a tendency to move at the circumference and bottom of a water tank. The velocity of moving goldfish was calculated from the time and distance. The average velocity of goldfish was in the range of 6-36 mm/s. A directional histogram (go straight and turn right or left) of a moving goldfish in an aquarium was made to measure an angle formed by two vectors, which were defined as three (middle to terminal against initial to middle) points in a unitary length (50 mm) of the path of goldfish. Three directions (go straight, right turn and left turn) were quantified as a percentage (59 +/- 12%, 20 +/- 4% and 20 +/- 4%, respectively) of a 1-h-event of moving goldfish. This image processing system thus can make an easy and quantifiable behavioral analysis of moving goldfish.

Algorithms↗
PubMed1996

Assessment of the course and variations of the hepatic artery in bile duct cancer by intraductal ultrasonography.

BACKGROUND: We evaluated the course and variations of the hepatic artery in bile duct cancer using intraductal ultrasonography (IDUS). METHODS: IDUS was used to demonstrate the course of the hepatic artery preoperatively in 20 patients with extrahepatic bile duct cancer, and the image was compared with angiographic and surgical findings. RESULTS: IDUS was able to assess tumor invasion to the main branch of the right hepatic artery in all cases. However, it demonstrated only three cases in the left hepatic artery and four cases in the proper hepatic artery. When the hepatic artery indicated re-entry or bifurcation on the IDUS image, the proximal portion of re-entry or bifurcation was established as the proper hepatic artery, but when it showed neither re-entry nor bifurcation it was established as the right hepatic artery. CONCLUSIONS: IDUS demonstrated the main branch of the right hepatic artery in all cases, but was not useful for demonstration of the left and proper hepatic arteries. Correct assessment of re-entry and bifurcation was essential on IDUS images for making the distinction between the right hepatic artery and the proper hepatic artery.

Aged↗
PubMed1996

The opposite effect of tumor-infiltrating natural killer cells on in vivo priming of tumor-specific CD8+ T cells and CD4+ T cells.

Natural killer (NK) cells, which infiltrated the tumor site, were examined for their effects on the in vivo priming of tumor-specific CD8+ and CD4+ T cells. CD8+ T cells were responsible for the activity of B16 melanoma-specific cytotoxic T lymphocytes (CTL). The in vivo depletion of NK cells with anti-NK1.1 monoclonal antibody (mAb), prior to B16-immunization, significantly decreased the capacity of the spleen cells (s.c.) to generate B16-specific CTL after in vitro restimulation. However, the CD8+ T cells of the s.c. from NK cell-depleted and subsequently B16-immunized mice increased their potential to become B16-specific CTL compared with those from the B16-immunized mice. The tumor-infiltrating NK cells showed a low but significant degree of CTL activity against B16. In addition, the disrupted B16 melanoma cells demonstrated less of an ability to in vivo prime the tumor-specific CD8+ T cells. These findings thus suggest the possibility that the quick disruption of tumor cells by tumor-infiltrating NK cells consequently interfered with the in vivo priming of the tumor-specific CD8+ T cells. On the other hand, the CD4+ T cells of the s.c. from NK cell-depleted and subsequently B16-immunized mice showed less of a capacity to induce the tumor-specific CTL compared with those from B16-immunized mice. In addition, the delayed-type hypersensitivity response against B16 was significantly diminished by the in vivo depletion of NK cells prior to B16-immunization. These findings thus suggest that NK cells have a promoting effect on the in vivo priming of CD4+ T cells. Overall, however, our findings indicate that early-appearing tumor-infiltrating NK cells have an opposite effect on the in vivo priming of CD8+ and CD4+ T cells.

Animals↗
PubMed1996

IL-3 derived from CD4+ T cells is essential for the in vitro expansion of mast cells from the normal adult mouse spleen.

A null cell line (SCM1) was established by a culture of spleen cells (SC) from normal adult C57B1/6 mice with complete medium alone for 10 days and followed by weekly cultures with a 25% WEHI-3 cell culture supernatant. Phenotype analysis showed that the SCM1 cells were negative for CD3, Thy1.2, B220, Mac-1, Gr-1, NK1.1 and MHC class II, but were positive for MHC class I, Fc gamma RII/ III, Fc epsilon RI, c-kit and the receptor against wheat germ agglutinin. These findings suggested that the SCM1 cells were mast cells. In an in vitro proliferation assay. SCM1 cells proliferated in the presence of either IL-3 or stem cell factor (SCF), but not in the presence of IL-4, whereas IL-4 showed an augmenting effect on their proliferation in the presence of either IL-3 or SCF. In analysing the mechanism by which such mast cells could be expanded from normal adult mouse SC, the addition of anti-IL-3 MoAb, but not anti-SCF MoAb, into the initial culture inhibited the subsequent expansion of either IL-3-or SCF-responding cells. The prior depletion of CD4+ T cells abrogated the capacity of the SC to enhance the expansion of SCF-responding cells, and this inability was restored by the addition of IL-3. Moreover, the culture supernatant of normal adult SC alone contained considerable levels of IL-3. Taken together, our findings suggest that, in an in vitro culture, CD4+ T cell-derived IL-3 therefore enhances the expansion of mast cells from the normal adult mouse spleen.

Aging↗
PubMed1996

Specific immunotherapy with tumour-draining lymph node cells cultured with both anti-CD3 and anti-CD28 monoclonal antibodies.

For providing costimulatory signals, we utilized anti-CD28 monoclonal antibody (mAb) for the in vitro culture of tumour-draining lymph node (LN) cells. The proliferation of B16 melanoma-draining LN cells in the culture with anti-CD3 mAb was remarkably enhanced by the addition of anti-CD28 mAb. In culture with both anti-CD3 and anti-CD28 mAb, the B16-draining LN cells produced a higher level of interferon-gamma, but not interleukin-4, than with anti-CD3 mAb alone. The B16-draining LN cells efficiently expanded in the culture with both anti-CD3 and anti-CD28 mAb and subsequently with a low dose of IL-2 (anti-CD3 plus anti-CD28/IL-2). The expanded cells consisted predominantly of CD8+ T cells and showed a specific cytolytic activity, in a major histocompatibility complex (MHC) class I-restricted manner, even without in vitro restimulation. In addition, the adoptive transfer of the B16-draining LN cells, expanded in the culture protocol of anti-CD3 plus anti-CD28/IL-2, showed a significant anti-tumour effect against metastatic B16 melanoma in combination with IL-2. The cured mice thus acquired a specific protective immunity. Moreover, this protocol was also moderately effective against poorly immunogenic 3LL carcinoma. Overall, our results suggest the potential for another immunotherapeutic strategy based on 'the costimulatory theory' other than vaccination with B7-transfected tumour cells.

Animals↗
PubMed1996

The emergence of non-cytolytic NK1.1+ T cells in the long-term culture of murine tumour-infiltrating lymphocytes: a possible role of transforming growth factor-beta.

The mechanism by which murine tumour-infiltrating lymphocytes (TIL) decreased their anti-tumour activity during an in vitro culture with interleukin-2 (IL-2) was investigated. A phenotype analysis revealed that the TIL cultured for 7 days (TIL-d7) were exclusively NKI.1- CD4- CD8+ CD3+ cells and that this population was replaced by natural killer (NK)1.1+ CD4- CD8 CD3+ cells by day 27 (TIL-d27) during the culture of TIL. The TIL-d7 cells showed a cytolytic activity against B16 melanoma, whereas the TIL-d27 cells had lost this activity, suggesting that the decrease in the anti tumour effect of TIL during the culture with IL-2 was due to their populational change. Analysis on the characteristics of the TIL-d27 cells revealed that they expressed skewed T-cell receptor (TCR) V beta 5 and increased mRNA expression of V alpha 14. In addition, they expressed transforming growth factor beta (TGF-beta) mRNA. Interestingly, TGF-beta augmented the proliferation of TIL-d27 cells under the presence of IL-2, but suppressed that of TIL-d7 cells. Moreover, the proliferation of TIL-d27 cells was suppressed by anti-TGF-beta monoclonal antibody. Collectively, these results suggest that, in contrast to its suppressive effect on anti-tumour effector T cells. TGF-beta could be an autocrine growth factor for NKL1.1+ T cells and thereby induce non-cytolytic NK1.1+ T cells in the long-term culture of TIL.

Animals↗
PubMed1996

Involvement of Na+,K(+)ATPase in the mitogenic effect of insulin-like growth factor-I on cultured rat astrocytes.

We have previously reported that insulin/insulin-like growth factor (IGF)-I induced the alpha 1 isoform of Na+,K(+)-ATPase in cultured astrocytes. In this study the effects of insulin/IGF-I on Na+,K(+)-ATPase activity and cell proliferation were examined in astrocytes cultured under the various conditions, to test the possible involvement of the enzyme activity in the mitogenic action of IGF-I on astrocytes. Insulin increased Na+,K(+)-ATPase activity and stimulated cell proliferation in subconfluent astrocytes (cultured for 7-14 days in vitro). In contrast, these effects were not observed in confluent cells (cultured for 28 days). Furthermore, insulin stimulated neither the enzyme activity nor [3H]thymidine incorporation in astrocytes preincubated in fetal calf serum-free medium for 2 days (quiescent cells) and treated with dibutyryl cyclic AMP (differentiated cells). The increases in Na+,K(+)-ATPase activity and expression of the alpha 1 mRNA preceded the mitogenic effect. 125I-IGF-I binding experiment showed that all the cells used here had similar binding characteristics. The insulin-induced increase in enzyme activity was not affected by 1-(5-isoquinolinesulfonyl)-2-methylpiperazine (H-7), and it was observed even in Ca(2+)-free medium. The stimulation by IGF-I of [3H]thymidine incorporation was attenuated by ouabain and a low external K+ level. These findings suggest that stimulation of Na+,K(+)-ATPase activity is involved in the mitogenic action of IGF-I on cultured astrocytes.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗
PubMed1996

[Mini-probe ultrasound of the upper gastrointestinal tract--1995 state of the art and perspectives. Workshop on Mini-Probe Ultrasound in Gastroenterology, Münster, 28 October 1995].

Endoscopic ultrasound (EUS) allows for intraluminal sonographic imaging of the oesophagus, stomach, pancreatobiliary duct system, the papilla of Vater, as well as the colon and rectum. EUS has proved valuable for diagnosis and staging of tumours of the upper intestinal tract. EUS can also provide valuable additional information concerning lesions that cannot be immediately classified. As doing this involves, first, removal of the conventional endoscope and, second, insertion of the echo endoscope, EUS is not suitable for routine examinations. Therefore EUS has remained an independent endoscopic diagnostic modality. Moreover, due to their diameter conventional echoendoscopes cannot be inserted into the pancreatobiliary duct system. Fine calibre high frequency ultrasound probes promise a resolution of less than 2 mm in diameter. The following report is a summary of a one-day workshop which took place in Muenster, Germany on Oct. 28, 1995. Its goal was to define the current state of the art of miniaturised endoscopic ultrasound probes in the field of gastroenterology. During this workshop, possible clinical applications for diagnosis, therapy, as well as follow-up were described and discussed. The potential of miniaturised endoscopic ultrasound probes was explored in terms of possible future technical developments.

Endoscopy, Gastrointestinal↗
PubMed1996

Assessment of pancreatic parenchymal invasion by bile duct cancer using intraductal ultrasonography.

BACKGROUND AND STUDY AIMS: This study was performed to clarify the diagnostic accuracy of intraductal ultrasonography (IDUS) in assessing pancreatic parenchymal invasion by bile duct cancer. PATIENTS AND METHODS: Preoperative assessment of pancreatic parenchymal invasion was carried out by IDUS via a percutaneous tract or a transpapillary route in 18 patients with extrahepatic bile duct cancer. Various probes with diameters of 1.4, 2.0, 2.4, 2.6 and 3.2 mm, and frequencies of 7.5, 15, 20 and 30 MHz were used. All patients underwent angiography and endoscopic ultrasonography (EUS). In the first six cases, IDUS and EUS images were analyzed retrospectively without knowledge of the operative outcome or the results of other imaging tests. In the subsequent 12 cases, the IDUS und EUS images were prospectively reviewed prior to surgery. The diagnostic accuracy of IDUS was compared with angiography and EUS by means of a histopathological examination of the resected specimens. RESULTS: The accuracy of IDUS, EUS, and angiography in assessing pancreatic parenchymal invasion was 100%, 78% and 61%, respectively. However, IDUS could not assess pancreatic capsular invasion. The accuracy of IDUS in assessing horizontal tumor extension to the intrapancreatic bile duct and to the hepatic side was 83% and 72%, respectively. CONCLUSIONS: IDUS proved useful for assessing the extension of cancer invasion to the pancreatic parenchyma, but not to the pancreatic capsule or mucosal surface.

Aged↗
PubMed1996

Ouabain-induced cell proliferation in cultured rat astrocytes.

Ouabain markedly stimulated not only [3H]thymidine incorporation but also [3H]uridine incorporation into astrocytes. The effects were observed at 36-48 hr and 12-72 hr after addition of ouabain, respectively. The dose-response curves were both bell-shaped types with a peak at 10(-3) M for thymidine incorporation and 2 x 10(-3) M for uridine incorporation. Ouabain increased cell number as determined by an assay using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide and by a method using a hemocytometer. Low concentration of external K+ mimicked the effect of ouabain in stimulating [3H]-thymidine incorporation, and high concentration of external K+ blocked the effect of ouabain. In contrast to astrocytes, ouabain did not stimulate [3H]thymidine incorporation into C6 glioma and fibroblast cells. The effect of ouabain on [3H]thymidine incorporation in astrocytes was dependent on external Ca2+, and it was blocked by cycloheximide. These findings indicate that prolonged Na+, K(+)-ATPase inhibition causes cell proliferation in cultured astrocytes in cell-specific and Ca(2+)-dependent manners.

Animals↗
PubMed1996

The antitumor effect induced by local injections with interleukin-2 is diminished by combing with a local injection with mitomycin C.

We investigated the antitumor effect of local injections with interleukin (IL)-2 in combination with an injection with mitomycin C (MMC). In BALB/c mice inoculated intraperitoneally (i.p.) with syngeneic Meth A fibrosarcoma on day 0, the i.p. injections with IL-2 at a dose of 20000U twice daily from day 7 to day 10 significantly prolonged survival of the treated mice and such treatment augmented a concomitant immunity specific for the tumor i.p. inoculated. On the other hand, the i.p. injections with IL-2 at a dose of either 5000U or 50000U resulted in no prolonged survival of the treated mice. In addition, neither intravenous nor subcutaneous injections with IL-2 at a dose of 20000U showed the prolonged survival of the treated mice. We further investigated a modulatory effect of a local injection with MMC on the IL-2-induced antitumor effect. The in vivo antitumor effect of local injections with IL-2 was not detected when combined with a local administration of MMC, whereas a systemic administration of MMC showed no such inhibitory effect on the IL-2-induced antitumor effect. Moreover, a delayed-type hypersensitivity response against Meth A, which was augmented by the local injections with IL-2, was significantly diminished by the local administration of MMC. Collectively, our results indicate that local injections with IL-2 could elicit the antitumor effect in vivo only when given at an optimal dose and that this effect could be rather diminished by combing with a local administration of MMC.

Animals↗
PubMed1996

[Clinical review of 105 cases of adrenal tumor, with special reference to incidental tumor].

We reviewed 105 patients with adrenal tumor diagnosed at our institute from January 1984 to December 1993. In 74 patients tumors were symptomatically diagnosed (the symptomatic group), while in the remaining 31 patients tumors were incidentally detected (the incidental group). In 5 cases of the incidental group, tumors were found at a routine health examination, whereas in the remaining 26 cases tumors were found during the examination or treatment for unrelated diseases. On both the incidental group and symptomatic group, higher right-to-left side ratio was noted in the laterality of tumors detected by ultrasound scanning. The size of tumors in the incidental group was significantly larger than that in the symptomatic group, but there was no significant difference in size between the tumors detected by ultrasound and those detected by CT scan in either the symptomatic group or in the incidental group. In the symptomatic group 71 patients (95.9%) were found to have functioning tumor, where the most common diagnosis was primary aldosteronism (44 cases), and 68 of the 71 patients received adrenalectomy. While in the incidental group 12 patients (38.7%) were found to have functioning tumor, where the most common diagnosis was pheochromocytoma (7 cases), followed by Cushing's syndrome (3 cases) including one case with so-called pre-Cushing's syndrome, and all of the 12 patients received adrenalectomy. Of 16 primary incidental adrenal tumors which did not have any hormonal functions, 5 tumors larger than 30 mm in diameter were resected and the remaining 11 tumors were followed up without operation. Since the incidence of incidental adrenal tumor may increase in the future, careful diagnosis and decision of indication for surgery are required.

Adolescent↗
PubMed1995

The involvement of transforming growth factor beta in the impaired antitumor T-cell response at the gut-associated lymphoid tissue (GALT).

We studied the antitumor immune response in gut-associated lymphoid tissue (GALT), which is the tolerance-inducing site for numerous dietary antigens. The mice inoculated with colon 26 carcinoma (C-26) into the subserosal space of the cecum (i.c.) showed a more rapid tumor growth than did the mice inoculated s.c. with C-26 into the flank. In addition, the serum of the i.c. C-26-inoculated mice showed a more potent suppressive activity, and their plasma contained a higher level of transforming growth factor than the s.c. C-26-inoculated mice. We also evaluated the tumor-specific T-cell response in the GALT by utilizing B7-transfected P815 mastocytoma (B7/P815). The rejection of i.c. inoculated B7/P815 was delayed compared to that of the s.c. inoculated B7/P815. The draining axillary lymph node (LN) cells of the s.c. B7/P815-inoculated mice exhibited a CD4+ T-cell-dependent proliferative response to in vitro restimulation, whereas the draining mesenteric LN cells of the i.c. B7/P815-inoculated mice exhibited no apparent response even with the addition of interleukin 2. However, such draining mesenteric LN cells did produce higher levels of interleukin 2 and transforming growth factor beta than the draining axillary LN without any stimulation, and their production of such cytokines depend on the CD4+ and CD8+ cells, respectively. Collectively, our results suggest the possibility that the impaired antitumor T-cell response in the GALT may be attributed to "bystander suppression" by TGF-beta-producing CD8+ T cells.

Animals↗
PubMed1995

Specific antitumor activity of tumor-infiltrating lymphocytes expanded first in a culture with both anti-CD3 monoclonal antibody and activated B cells and then in a culture with interleukin-2.

In order to expand tumor-infiltrating lymphocytes (TIL) efficiently and in order to use them for immunotherapy, we utilized lipopolysaccharide-activated B cells (LPS blasts) as costimulatory-signal-providing cells in an in vitro culture system. TIL, prepared from subcutaneously inoculated B16 melanoma, failed to expand when cultured with anti-CD3 monoclonal antibody (mAb) alone followed by a low dose of interleukin(IL)-2. In contrast, such TIL did expand efficiently in culture with both anti-CD3 mAb and LPS blasts followed by culture with IL-2. These findings suggest that the presence of LPS blasts in the initial culture was essential for the cell expansion. The expansion of TIL was partially blocked by the addition of CTLA4 Ig, which is an inhibitor of costimulatory molecules such as CD80 and CD86, and was almost blocked by the addition of anti-(Fc receptor gamma II)mAb. These findings thus indicate that such molecules, in conjunction with the receptor on the LPS blasts, participate in the efficient expansion of TIL. The B16-derived TIL, which expanded in our culture system, were predominantly CD8+ T cells and showed a higher level of cytolytic activity against B16 melanoma than either lymphokine-activated killer cells or TIL cultured with a high dose of IL-2. In addition, the in vitro expanded B16-derived TIL produced interferon gamma, but not IL-4, in response to B16 melanoma. What is more important, the adoptive transfer of such TIL had a significant antitumor effect against pulmonary metastasis in B16 melanoma, even without the concurrent administration of IL-2. Collectively, our results thus indicate the therapeutic efficacy of the protocol presented here for antitumor immunotherapy with TIL.

Abatacept↗
PubMed1995

Assessment of portal vein invasion by bile duct cancer using intraductal ultrasonography.

BACKGROUND AND STUDY AIMS: We recently reported on the contribution of intraductal ultrasonography (IDUS) to the regional staging of bile duct cancer, and we present here the first detailed study of the value of IDUS in assessing the portal vein invasion by bile duct cancer. PATIENTS AND METHODS: Preoperative assessment of portal vein invasion was performed by IDUS via a percutaneous tract or via transpapillary route in 18 patients with extrahepatic bile duct cancer. Various probes, with diameters of 1.4, 2.0, 2.4, 2.6, and 3.2 mm, and frequencies of 7.5, 15, 20, and 30 MHz, were used. All patients additionally underwent endoscopic ultrasonography (EUS) and angiography. In the first six cases, the IDUS and EUS images were analyzed retrospectively without the knowledge of operative results or the other imaging tests. In the remaining 12 cases, IDUS and EUS images were prospectively reviewed prior to surgery, without knowledge of the angiographic findings. The gold standard for the results of IDUS, EUS and angiography was the histopathological findings in 17 resected tumors, and the intraoperative findings in one patient who did not undergo resective surgery. RESULTS: IDUS was able to demonstrate the portal vein in all cases. Its accuracy in diagnosing portal vein invasion was 100% for all locations. EUS was useful in assessing portal vein invasion at the middle and distal bile duct (the accuracy was 91%), but was not useful in assessing invasion at the proximal bile duct (the accuracy was 57%). CONCLUSIONS: IDUS proved useful for assessing the extension of cancer invasion into the portal vein, even in proximal bile duct tumors.

Aged↗
PubMed1995

Assessment of hepatic artery invasion by bile duct cancer using intraductal ultrasonography.

BACKGROUND AND STUDY AIMS: This study was performed to clarify the diagnostic accuracy of intraductal ultrasonography (IDUS) in assessing hepatic artery invasion by bile duct cancer. PATIENTS AND METHODS: Preoperative assessment of hepatic artery invasion was performed by IDUS via a percutaneous tract or the transpapillary route in a total of 22 patients with extrahepatic bile duct cancer. The probes used had a diameter of 1.4, 2.0, 2.4, 2.6, and 3.2 mm, and frequencies of 7.5, 15, 20, and 30 MHz. In the first six cases, IDUS images were analyzed retrospectively with no knowledge of the operative results or of the other imaging tests. In the following 16 cases, the IDUS images were prospectively reviewed prior to surgery without knowledge of the angiographic findings. The diagnostic accuracy of IDUS was compared with angiography in all cases, with the histopathological results in 20 resected cases, and with the intraoperative findings in two cases with only surgical exploration. RESULTS: IDUS was able to demonstrate the right hepatic artery in all cases, and its accuracy in diagnosing right hepatic invasion was 100%. However, IDUS was able to visualize the proper hepatic artery in only four cases (18%), and the left hepatic artery in only three cases (14%), respectively. IDUS could not visualize the area outside of the hepatoduodenal ligament, because of its low penetration depth. CONCLUSIONS: IDUS proved useful for assessing the extension of bile duct cancer invasion into the right hepatic artery. However, IDUS did not sufficiently demonstrate the proper hepatic artery and the left hepatic artery for diagnosing vascular involvement.

Aged↗