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Biomedical subjects

K Orita

Publications and source records attributed to K Orita.

At least 145 records · Page 8Linked to original sources
PubMed1994

[The expression of neural cell adhesion molecule (NCAM), neural invasion and recurrence patterns in rectal cancer--a study using anti-NACM (neural cell adhesion molecule) antibody].

Neural invasion may be one of the main causes of local recurrence, but its mechanism has not been sufficiently clarified. We previously reported that the expression of NCAM on cancer cells was correlated with neural invasion in pancreatic cancer. In this study, we examined the neural affinity of rectal cancer cells and the relationship between neural invasion and recurrence patterns of rectal cancers. A total of 64 rectal adenocarcinoma were examined. Specimens from 17 patients (27%) revealed perineural invasion. The incidence of neural invasion increased with the frequency of venous invasion and the degree of lymph node metastasis, but not significantly. The incidence of the expression of NCAM in rectal cancer cell was 45.3 percent. Neural invasion of rectal carcinoma was significantly related to the expression of NCAM (p < 0.05). NCAM immunocytolocalization was classified into the focal type, and the diffuse type. Concerning the recurrence type, 8 of 9 cases that developed local recurrence showed either presence of neural invasion or expression of NCAM. Liver metastasis was associated with absence of neural invasion or NCAM expression. The expression of NCAM may contribute to local recurrence, whereas the absence of NCAM may predict liver metastasis.

Adenocarcinoma↗
PubMed1994

Cell cycle assessment of adoptive transferred lymphokine activated killer cells.

The use of lymphokine activated killer (LAK) cells for adoptive transfer therapy has been reported from number of clinical trials. To our knowledge, however, there has been no report concerning the cell cycle progression of LAK cells. Thus, for the present study we have attempted to examine the LAK cell cycle either before or after transfer. In vitro and in vivo analyses of LAK cells labeled with bromodeoxyuridine (BrdU) were carried out using two-parameter flow cytometries of their nuclear staining using fluorescein isothiocyanate(FITC)-conjugated anti-BrdU antibody and propidium iodide (PI). The in vitro growth of BrdU-positive cells showed the cells to divide once in the S phase, continue to the G2-M phase and return to the G0-G1 phase with a similar pattern after 48 or 72 h culture. They formed a definite subpopulation and were of phenotypes, thy-1.2 (+), Lyt-1.1 (-), Lyt-2.1 (+), L3T4 (-) and AGM1 (+). The percentage of BrdU-positive cells decreased significantly (P < 0.05) when treated with complement plus anti-thy-1.2, anti-Lyt-2.1 or anti-AGM1 anti-bodies, demonstrating BrdU-labeled LAK cells to have the same phenotype as control LAK cells. As in vitro, the in vivo cell cycle of LAK cells 48 and 72 h after transfer had a similar pattern, and the LAK cells also continued on to the S phase after the first division. The in vivo growth of the LAK cells treated with interleukin-2 (IL-2) was promoted 24 and 48 h after transfer. In conclusion, the present study showed LAK cells to be capable of dividing following transfer and to keep their own phenotypic characteristics; also, that treatment with IL-2 may promote their division. Adoptive transfer therapy seems to be a viable therapeutic method.

Animals↗
PubMed1993

Effect of reactive oxygen intermediates on the in vitro invasive capacity of tumor cells and liver metastasis in mice.

We studied the role of reactive oxygen intermediates (ROIs) in experimental liver metastasis induced in mice by the inoculation of COLON 26-M5 murine colon cancer cells, a highly metastatic variant of COLON 26 cells, and the effect of ROIs on the invasive capacity of the cells in an in vitro chemo-invasion assay model using reconstituted basement membrane matrigel. We also measured the release of ROIs from cells using electron spin resonance (ESR) spectrometry. Hydroxyl radicals (.OH) were constitutively released from the cells. This release was augmented by pre-treatment with phorbol 12-myristate 13-acetate (PMA). In experimental liver metastasis in CDF1 mice, the administration of recombinant human superoxide dismutase (r-hSOD) significantly increased the number of metastatic nodules, while administration of catalase significantly inhibited metastasis formation. In vitro pre-treatment of cells with PMA significantly increased the number of metastatic nodules. Invasive capacity of the cells was markedly augmented by pre-treatment with PMA. PMA-induced augmentation was significantly inhibited by the simultaneous addition of r-hSOD to the assay. Catalase had no significant effect. Our findings suggest that ROIs play an important role in tumor invasion and metastasis, and that hydrogen peroxide (H2O2) may contribute to the retention or extravasation of circulating tumor cells. Furthermore, the superoxide anion (O2-) released by tumor cells may play an important role in basement membrane degradation.

Animals↗
PubMed1993

Alteration in the retinoblastoma gene associated with immortalization of human fibroblasts treated with 60Co gamma rays.

Genetic analysis was carried out in human fibroblasts (KMST-6) immortalized by treatment with 60Co gamma rays in order to determine if any genetic change was involved in the immortal transformation of human cells. Analysis by restriction fragment length polymorphism revealed an alteration in chromosome 13q12-14, in which the retinoblastoma (RB) gene locus (13q14) is located. Then the RB gene itself was examined. Structural abnormalities in the RB gene were detected by Southern blot analysis. Furthermore, abnormal RB protein (pRB) was expressed in immortalized KMST-6 cells, as shown by in vitro phosphorylation, whereas normal KMS-6 cells expressed the intact pRB. These findings indicated that inactivation of the RB gene is one of the key events of the immortalization of human cells.

Cell Transformation, Neoplastic↗
PubMed1993

Regulation of liver regeneration by interleukin-2 and its inhibitors: cyclosporine A and FK 506.

Several investigations have been suggesting that lymphocytes can be responsible for growth regulation of liver. The interleukin-2 (IL-2) production by spleen cells was noted to be increased 2 days after resection of 70% of the volume of the liver in C3H/He mice. The effects of IL-2 production and its antagonists: cyclosporine A (CsA) and FK506 on liver regeneration were thus studied by measuring in vivo incorporation of Bromodeoxyuridine (BrdU). By intraperitoneal injection of IL-2 5 times every 8 h after hepatectomy. BrdU labeling indices at 36 h after the operation were suppressed in a dose-dependent manner. On the other hand, treatment with CsA and FK506, which inhibit IL-2 production, increased the mitotic indices of the regenerating livers. Serum levels of aminotransferases were not affected by FK506 at a dose sufficient for the mitotic stimulation. Based on these results, CsA and FK506 would appear to stimulate liver cell proliferation by suppressing IL-2 production and inhibiting of NK cell activity.

Animals↗
PubMed1993

Differing roles of protein kinase C on the signal transduction of tumour necrosis factor-alpha and -beta on PANC-1 cells: in vitro autoradiographic investigation.

We investigated alterations in protein kinase C (PKC) activity of PANC-1 cells following treatment with tumour necrosis factor (TNF)-alpha or TNF-beta by an in vitro autoradiographic method. Binding studies performed on whole cells using [3H]phorbol-12,13-dibutyrate (PDBu) as a ligand revealed strong activation of PKC by TNFs within 30 min. The effect was similar to that seen after 30 min treatment with 12-O-tetradecanoylphorbol-13-acetate (TPA). After treatment for 24 h, TNF-beta caused a marked down-regulation of PKC similar to that seen after 24 h treatment with TPA; significant activation persisted, however, in the cells treated for 24 h with TNF-alpha. Our data suggest that PKC activation may play a more important role in the TNF-alpha signal transduction pathway than in that of TNF-beta.

Autoradiography↗
PubMed1993

Synthesis and evaluation of 1-(1-[5-(2'-[18F]fluoroethyl)-2-thienyl]-cyclohexyl)piperidine as a potential in vivo radioligand for the NMDA receptor-channel complex.

1-(1-[5-(2'-[18F]Fluoroethyl)-2-thienyl]cyclohexyl)piperidine (18FE-TCP) was prepared as a fluorine-substituted analogue of the potent NMDA receptor channel blocker, 1-[1-(2-thienyl)cyclohexyl]piperidine (TCP), by the mesylate displacement with [18F]fluoride ion with isolated radiochemical yields of 6-12%, and the synthesis time including a two step HPLC purification was 120 min. The regional distribution in rat brain after i.v. injection of 18FE-TCP was heterogeneous and similar to the known distribution of phencyclidine recognition sites, with hippocampus-cerebellum, striatum-cerebellum and cerebral cortex-cerebellum concentration ratios of 2.08, 1.7 and 1.54, respectively, 15 min post-injection. Furthermore, this localized regional cerebral distribution was blocked by co-injection with the unlabelled FE-TCP or pretreatment with cis-2-hydroxymethyl-r-1-(N-piperidyl)-1-(2-thienyl)cyclohexane, with the greatest reductions seen in the hippocampus followed by the striatum and cerebral cortex. However, relatively low receptor binding affinity and high non-specific binding due to its high lipophilicity suggest that 18FE-TCP may not be a suitable radioligand for in vivo PET investigations of the NMDA receptor-channel complex.

Animals↗
PubMed1993

Establishment and characterization of a SV40 T-antigen immortalized epithelial-like cell line derived from the newborn rat colorectum and its malignant transformation by the ras oncogene.

Epithelial-like cells from the colorectum of one-day-old newborn rats were immortalized by transfection with the simian virus 40 (SV40) T-antigen gene, and a cell line OUMS-25 was established. The cells were positive for the SV40 T-antigen, and immunoreactive to a colonic epithelial cell monoclonal antibody and a keratin-18 monoclonal antibody. Ultrastructural studies revealed the presence of microvilli on the cell surface and desmosomes between the adjacent cells. Karyotypic analysis showed that OUMS-25 cells were aneuploid. Cloning efficiency of the cells was 0.01% in soft agar. However, the cells were not tumorigenic in the syngeneic newborn rats. The cells were further transformed by transfection with the cloned activated c-Ha-ras oncogene containing a point mutation within codon 61. Characteristics of the activated-c-Ha-ras transfected cells (OUMS-25/RAS) were different in some respects from those of the parent cells (OUMS-25). OUMS-25/RAS cells demonstrated more malignant morphology, elevated cloning efficiency in soft agar, and tumorigenicity. This is the first report on the immortalization and malignant transformation of colorectal epithelial-like cells by transfection with a combination of SV40 T-antigen gene and cloned activated c-Ha-ras oncogene.

Animals↗
PubMed1993

An analysis of DNA ploidy pattern of hepatocellular carcinoma.

To determine whether a relationship exists between DNA ploidy and the prognosis of hepatocellular carcinoma (HCC), flow cytometric DNA analysis was performed in paraffin-embedded specimens obtained from 44 patients with HCC who underwent hepatectomy. There were 26 diploid (59%) and 18 aneuploid (41%) tumors. No correlation was shown between DNA ploidy pattern and patient age, sex, liver cirrhosis, hepatitis B virus antigen and serum alpha-fetoprotein level. The ploidy pattern had no significant correlation with the presence of vascular invasion or intrahepatic metastasis. Only Edmondson's grade was well correlated with the ploidy pattern. We noted a significant correlation between survival rates and the presence of vascular invasion or intrahepatic metastasis (p < 0.05). In contrast, no significant correlation was found between DNA ploidy pattern and the prognosis of HCC. The results of this study indicate that DNA ploidy pattern may not be a useful indicator for the prognosis of HCCs after hepatic resection, unlike the results of gastric and colon cancers.

Carcinoma, Hepatocellular↗
PubMed1993

Immunotherapy by a slow delivery system of interleukin-2 in mice models.

A sustained release system for interleukin-2 (IL-2), and IL-2 mini-pellet (IL-2 mp), was developed by fusing IL-2 into a needle shaped collagen. Serum concentration of IL-2 after a single subcutaneous injection of the IL-2 mp into C57BL/6 mice remained elevated longer than after an injection of aqueous IL-2. IL-2 in the serum became undetectable by 6h after a subcutaneous injection of 1 x 10(6) unit of IL-2 in phosphate-buffered saline (PBS). In contrast, after a single subcutaneous injection of IL-2 mp containing the same amount of IL-2, the concentration of IL-2 increased to its maximum at 6h after injection, then began to decrease gradually. IL-2 was detected even on the third day after a single subcutaneous injection of one IL-2 mp. Augmentation of NK activity and generation of IL-2 activated killer cells were observed in the spleen from day 1--day 3 after a single subcutaneous injection of IL-2 mp into C57BL/6 mice. This activation was not observed following a single subcutaneous injection of the same amount of IL-2 in PBS. Adoptive immunotherapy by a single subcutaneous injection of IL-2 mp followed by intravenous injections of in vitro cultured IL-2 activated killer cells showed better results in decreasing the number of metastases of Lewis lung carcinoma in C57BL/6 mice than immunotherapy using IL-2 solution.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1993

Beneficial effect of EPC-K1 on the survival of warm ischemic damaged graft in rat cardiac transplantation.

A newly introduced compound, EPC-K1, represents a phosphate diester linkage of vitamin E and vitamin C. The effect of EPC-K1 on the reperfusion injury was evaluated in a heterotopic cardiac transplantation model using syngenic combination rats. Prior to the warm ischemia, 12mg EPC-K1/kg was administered intravenously to donor rats. After 15 min of warm ischemic time, hearts were harvested and perfused with 4 degrees C saline. After completion of the transplantation, recipient rats were also treated with intravenous 12 mg EPC-K1/kg, before reperfusion. Saline was used instead of EPC-K1 for both donors and recipients in the control group. On the 7th post-transplantation day, graft survival was 7 out of 8 in EPC-K1 group, versus 1 out of 9 in the control group (p < 0.001). Thiobarbituric acid-reactive substance levels in the recipient serum, three hours after reperfusion, were significantly limited, in the group in which EPC-K1 was administered only to donors. But it was not possible to clarify whether the effect of EPC-K1 is primarily at the donor or recipient levels at this time. These results indicate that EPC-K1 may reduce reperfusion injury after cardiac transplantation. This beneficial effect may be mediated by the hydroxyl radical scavenging properties of EPC-K1.

Animals↗
PubMed1993

Successful pregnancy in renal transplant recipients.

Three cases of successful pregnancies in renal transplant recipients who had undergone transplantation in the Okayama University Medical School Hospital are reported. Two of the women had received an organ from a living relative and one woman received a cadaveric organ graft. These patients, aged 28-37 at the time of the delivery, had received their transplants 2-5 years prior to their conception. The periods of gestation ranged between 35 and 40 weeks. The weight of the babies at birth ranged from 2,380g to 2,500g and the apgar score at 1 min was 8 or 9. None of the infants showed any congenital abnormalities. Lower-segment cesarean section was performed in all of three cases. Serum creatinine levels, an indicator of renal graft function, did not deteriorate during the pregnancy or after delivery. Although further work is needed to solve problems regarding pregnancy in renal transplant recipients, these results encouraged us to meet their hope for a baby.

Adult↗
PubMed1993

Common bile duct injury during laparoscopic cholecystectomy.

Bile duct injury can occur more frequently during laparoscopic cholecystectomy than in open cholecystectomy. Three cases of common bile or hepatic duct injuries occurred in a series of eighty laparoscopic cholecystectomies; In case 1, the common bile duct was misidentified as the cystic duct. In case 2, bile peritonitis occurred on the fourth postoperative day caused by necrosis of the common hepatic duct involving the cautery surrounding it. In case 3, a bile leak occurred due to an incision at the confluence of the cystic and common duct. Dissection of the cystic duct at the infundibulum of the gallbladder, blunt dissection of the Calot's triangle, the handling of clips with special attention for safety were thought to be necessary in order to lower the risk of bile duct injury. Preoperative endoscopic retrograde cholangiography (ERCP) is recommended to avoid bile duct injury.

Adult↗
PubMed1993

Therapeutic effect of neuraminidase-treated LAK cells on liver metastasis of Colon 26.

To improve the lymphokine-activated killer (LAK) cell therapy for liver metastasis, two methods which enhance accumulation of LAK cells in the liver were examined for their effects on the liver metastasis of Colon 26 cancer cells in BALB/c mice. Distribution of LAK cells in the mice was examined by the 51Cr labeling method. Portal vein infusion of LAK cells or tail vein infusion of neuraminidase treated-LAK (N-LAK) cells showed an augmented accumulation of infused cells in the liver. In the first experiment, LAK cells (5 x 10(7) cells) were infused in the portal vein or tail vein at days 3 and 7 after the inoculation of 5 x 10(4) tumor cells and 1 x 10(4) units of IL-2 were given three times a day from day 3 to day 7. The portal infusion of LAK cells produced a greater reduction of liver metastases compared with the peripheral infusion. In the second experiment, 5 x 10(7) LAK cells or N-LAK cells were infused via the tail vein on days 1 and 3, and 1 x 10(4) units of IL-2 were given once a day from day 1 to day 5 after the inoculation of 1 x 10(4) tumor cells. The therapeutic effect of N-LAK cells was greater than non-treated LAK cells on the number of metastatic lesions and the survival time of mice. Since access to the human portal vein is difficult and risky in clinical situation, peripheral infusion of N-LAK cells is preferable.

Adenocarcinoma↗
PubMed1993

Inhibition of liver regeneration in mice following extended hepatectomy by transfusion of lymphokine activated killer cells.

Lymphokine activated killer (LAK) cells can destroy not only tumor cells but also syngeneic liver cells. In this study, the effects of passive transfer of LAK cells on liver regeneration were examined by the 3H-thymidine uptake and bromodeoxyuridine (BrdU) labeling methods after resection of 70% of the volume of the liver. LAK cells were infused 12h after hepatectomy and the effects on regeneration of liver cells were examined 36 h later. The transfusion of LAK cells induced significant inhibition of liver regeneration at a dose of 5-10 x 10(7) cells. Neuraminidase treatment of lymphocytes is desirable to enhance the selective entrapment of LAK cells into the liver. When LAK cells were treated with neuraminidase (0.5 units/ml), and transfused into hepatectomized mice, more potent suppression of liver regeneration was induced in comparison with the same dose of LAK cells. The intraperitoneal injection of recombinant interleukin 2 (rIL-2) after partial hepatectomy also inhibited the regeneration of remnant liver. From these results, lymphocytes such as LAK cells appear to regulate liver regeneration.

Animals↗