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Biomedical subjects

T Ochiai

Publications and source records attributed to T Ochiai.

At least 127 records · Page 7Linked to original sources
PubMed1999

Salt-Sensitive growth of Staphylococcus aureus: stimulation of salt-induced autolysis by multiple environmental factors.

The growth of Staphylococcus aureus 209P became extremely sensitive to a high NaCl concentration following lowered temperature, reduced air-supply, and decreased Ca2+ concentration in the medium. Cells in high-NaCl and low-Ca2+ concentration media either autolyzed or transformed into protoplast-like forms during growth when grown standing below 37 degrees C. The abnormal growth, however, was invariably avoided by preliminary supplementation with polyanetholesulfonate (autolysin inhibitor) in the growth media. These results suggested that the autolytic activity of this organism was precisely controlled by multiple environmental factors such as ionic strength, temperature, air supply, and the concentration of Ca2+.

Bacteriolysis↗
PubMed1999

Frequent expression of midkine gene in esophageal cancer suggests a potential usage of its promoter for suicide gene therapy.

We have examined the expression of midkine (MK), a neurotrophic factor with heparin-binding activity, in human esophageal cancer cells. Seven esophageal cell lines tested expressed the transcript and 8 out of 14 human esophageal tumor specimens were positively stained with anti-MK antibody, while surrounding normal esophageal tissues in these specimens were not stained. The 5'-flanking, 2.3 kb genomic region of the MK gene was shown to drive the transcription of a reporter gene in the esophageal cell lines in a cis acting manner. Forced expression in esophageal cancer cells of herpes simplex virus-thymidine kinase gene mediated by the flanking region of the MK gene conferred sensitivity to a prodrug, ganciclovir. The 5'-upstream region of the MK gene thus possesses putative promoter activity which can be used for suicide gene-based gene therapy for esophageal cancer.

Aged↗
PubMed1999

Gamma Knife radiosurgery for pituitary adenomas.

Ninety-two patients with pituitary adenomas have been treated during the last 5 years. Sixty-three of these patients had more than 6 months follow-up, and they form the basis of this report. Eighteen had non-functioning adenomas (NFA), and 36 had functioning adenomas (FA). The mean marginal dose was 22.5 Gy (NFA 19.5 Gy, FA 23.9 Gy). Control of tumor growth was achieved in 92%. A significant decrease of excessive hormone production was seen in 75.6%, and the endocrinopathy normalization rate was 26.7%. Post-radiosurgical complications were seen in 4.7%.

Acromegaly↗
PubMed1999

Enhanced effects of monoclonal antibody carboplatin immunoconjugates uptake and anti-tumor effects with angiotensin II and tumor necrosis factor.

The most important factor influencing the use of monoclonal antibody immunoconjugates for cancer treatment is effectiveness of enhancement for tumor targeting. We call attention to the vasoactive agents angiotensin II (ATII) for selective increase in tumor blood flow and cytokine tumor necrosis factor (TNF) to improve the vascular permeability of the tumor. Tumor localization and biodistribution were investigated by nude mice transplanted human colon adenocarcinoma (LS-180) with radiolabeled carboplatin immunoconjugates. Tumor activity 48 h after administration of ATII and TNF was significantly higher than in the control group. However, nonspecific accumulation in normal organs was not observed. In vivo anti-tumor effects in animals with ATII and TNF was significantly stronger than in those given the same dose drug alone or immunoconjugates alone. These results indicate that ATII and TNF could be useful tools for induction of stronger inhibition of tumor growth without systemic toxicity.

Adenocarcinoma↗
PubMed1999

Chromosome breakage and cell lethality in human hepatoma cells irradiated with X rays and carbon-ion beams.

Prediction of radiosensitivity would be valuable for heavy-ion radiotherapy. Premature chromosome condensation (PCC) technique has been a potential predictive assay in photon radiotherapy, but has not been investigated for hepatomas receiving heavy ions. Two human hepatoma cell lines, i.e., HLE and HLF, were irradiated with either 290 MeV/u carbon ions or 200 kVp X rays. Cell lethality was assayed by colony formation and compared with the unrejoined fraction of chromatin breaks as measured by PCC technique. Carbon ions at linear energy transfer (LET) of 76 keV/micron produced cell death more effectively than those of 13 keV/micron and X rays. For the cell killing, the relative biological effectiveness (RBE) of 13 and 76 keV/micron carbon ions compared with X rays was 1.10-1.24 and 2.57-2.59, respectively. Mean number of chromosomes in HLE and HLF cells was similar to each other, i.e., 60.48 and 60.28. RBEs for chromatin breaks of 13 and 76 keV/micron carbon ions were 1.30-1.31 and 2.64-2.79, respectively. A strong correlation between unrejoined chromatin breaks and cell killing for human hepatoma cells was observed irrespective of radiation quality. We conclude that PCC provides a potential predictor for the radiosensitivity of individual hepatoma that are treated with photon as well as heavy ion irradiation.

Carbon↗
PubMed1999

Rotational cine cholangiography: evaluation for use in diagnosing bile duct carcinoma.

OBJECTIVE: We evaluated the usefulness of rotational cine cholangiography in the preoperative diagnosis of bile duct carcinoma. SUBJECTS AND METHODS: Rotational cine cholangiography was performed in both the transverse and cephalad anterior oblique planes in 60 patients with obstructive jaundice. Using strict diagnostic criteria, the capability of this technique to detect the confluence of the right hepatic duct and the left hepatic duct, the right anterior segmental duct and the right posterior segmental duct, and the left medial segmental duct was investigated. The angle at which the confluence was revealed was also investigated. In 26 patients with resected bile duct carcinomas, the preoperative diagnosis of cancer spread obtained using this procedure was compared with the histopathologic findings. RESULTS: Overall detectabilities of the confluences of the right hepatic ducts and left hepatic ducts, the right anterior segmental ducts and right posterior segmental ducts, and the left medial segmental ducts were 97.6%, 87.0%, and 93.1%, respectively. The angles of the confluences of the right hepatic ducts and left hepatic ducts and of the right anterior segmental ducts and right posterior segmental ducts were widely distributed: on the other hand, those of the left medial segmental ducts were distributed mainly from 0 degrees to 20 degrees . The accuracies of diagnosis of cancer invasion were 91.7% in the common hepatic ducts, 100% in the right hepatic ducts, 91.7% in the left hepatic ducts, 100% in the right anterior segmental ducts, 83.3% in the right posterior segmental ducts, and 100% in the left medial segmental ducts. CONCLUSION: Rotational cine cholangiography is reliable not only in detecting the confluence of the bile ducts but also in diagnosing the longitudinal extent of cancer spread along the bile duct wall.

Aged↗
PubMed1999

Expression of wild-type p53 gene confers increased sensitivity to radiation and chemotherapeutic agents in human esophageal carcinoma cells.

The status of the p53 gene of tumor cells can modify the sensitivity of the tumors to radiation and anti-cancer agents. Human esophageal cancer cells (T.Tn) bearing mutated p53 gene were retrovirally transduced with wild-type p53 gene. The transduced cells (T.Tn/p53) which stably expressed wild-type p53 proliferated at the same rate as parental cells. However, the sensitivity to radiation was significantly improved by the transduction and T.Tn/p53 cells became markedly susceptible to cisplatin and etoposide compared with parental cells. Administration of cisplatin noticeably suppressed the growth of T.Tn/p53 tumors but not T.Tn tumors inoculated in nude mice. Forced expression of wild-type p53 gene thereby can increase the sensitivity to DNA damage in esophageal cells.

Animals↗
PubMed1999

Loss of tumorigenicity of human breast cancer cells engineered to produce IL-2, IL-4 or GM-CSF in nude mice.

Human breast cancer cells (OCUB-M), retrovirally transduced with granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin-2 (IL-2) or IL-4 gene were examined for their antitumor activities in nude mice. Although cell proliferation rates in vitro of these cytokine-producing cells were not significantly different from that of wild-type cells, nude mice that were subcutaneously inoculated with cytokine-producing cells did not develop tumors in contrast to mice that were injected with wild-type cells. Injection of GM-CSF-producing cells into the vicinity of growing wild-type tumors retarded subsequent growth of wild-type tumors. Histological examination of tumors which received GM-CSF-producing cells revealed marked infiltration of mononuclear cells around the tumors. Irradiation of cytokine-producing cells diminished their proliferation capacity but production of cytokine(s) was retained. Therefore, inoculation of irradiated cytokine producer cells into growing tumors can be used as a therapeutic maneuver for breast cancer.

Animals↗
PubMed1999

P16INK4a expression adenovirus vector to suppress pancreas cancer cell proliferation.

The prognoses of pancreatic cancer patients have been miserable even after radical surgery, and adjuvant therapy is necessary to improve the surgical results. p16(INK4a) (p16) is tight-binding and inhibitory protein for cyclin-dependent kinase 4 to induce G1 arrest of the cell cycle. p16 gene deletion is frequently identified in human pancreas cancer. The impaired gene function of p16 might be a major factor of the uncontrolled proliferation and malignancy of pancreas cancer cells. In this study, we investigated the effect of adenovirus p16 expression vector for pancreas cancer cell proliferation to clarify whether the vector might be a promising mode to assist the surgical therapy for pancreas cancer. We constructed the adenovirus p16 expression vector AdexCACSp16 by inserting p16 cDNA to a cassette cosmid containing a nearly full-length adenovirus type 5 genome with E1 and E3 deletions. Thereafter, we assessed the activity of AdexCACSp16 to induce p16 gene mRNA expression in pancreas cancer cell line MIAPaCa-2 and to control cell proliferation. AdexCACSp16 induced a high level of p16 gene mRNA expression in MIAPaCa-2 cells with 1 h contact to the cells. The cell proliferation was significantly suppressed by AdexCACSp16 compared with the control adenovirus group. These data indicate that AdexCACSp16 has the potential to induce p16 gene expression and control pancreas cancer cell proliferation and that the adenovirus p16 expression vector AdexCACSp16 might be a possible method of gene therapy to improve the surgical therapeutic results for pancreas cancer.

Adenoviruses, Human↗
PubMed1999

[Detection of serum p53 antibodies in colorectal cancer patients and the clinical significance of postoperative monitoring].

p53 protein overexpression was found to induce the production of antibodies in patient serum and, recently, the easy detection of serum antibodies has been made possible. The aim of this study is to determine the significance of serum p53 antibodies in patients with primary colorectal adenocarcinoma in comparison with their clinicopathological features, and the tumor marker sensitivities of carcinoembryonic antigen (CEA), carcinoma antigen 19-9 (CA19-9) and alpha-fetoprotein (AFP). Thirty-nine of 86 patients (45.3%) were positive for serum p53 antibodies. However, there was no relation with the cancer progression or clinicopathological findings. The sensitivities of CEA, CA19-9 and AFP were 36.0%, 38.4%, and 8.1% respectively, but there was no relation between serum p53 antibodies and these three markers. When the sensitivity of serum p53 antibodies and CEA was evaluated according to clinical stage, the presence of serum p53 antibodies was more significantly associated with stage 0, I and II colorectal cancer than was CEA. Thirty-three patients who showed preoperative positivity for serum p53 antibodies were followed by serial evaluation of circulating antibodies after resection. Negative conversions after resection were significantly higher in the "Cur A" group than in the "Cur B" or "Cur C" groups. Serum p53 antibodies appear to be a useful tumor marker independent of the other markers, especially in the early stage, and are expected to be useful in the development of a method of early diagnosis for mass screening, and as a postoperative monitoring marker for colorectal cancer.

Adult↗
PubMed1998

Evaluation of a new staging system by the Japanese Research Society for Gastric Cancer.

The feasibility of the new classification of stage grouping by the Japanese Research Society for Gastric Cancer was evaluated. During the 22-year period between January 1975 and December 1996, a total of 1294 patients with primary gastric cancer underwent laparotomy at the Department of Surgery, Chiba University; 1222 had their lesions removed during the gastrectomy and 72 remained nonresected. Cases of direct operative death totaled 17 (1.3%). Five hundred patients (38.6%) died of a relapse of the original cancer and 42 (3.2%) died of other diseases within the followup period. Six patients (0.5%) were lost during the followup. The 5-year cumulative patient survival rates of the seven stages of the new stage grouping were distinctly proportional, and the differences were also statistically significant except between stages IIIb and IVa. The two major revised points in the new stage grouping, new classification of the depth of cancer invasion, and new stage grouping by a mosaic combination of the degree of invasion and lymph node metastasis were thus found to be reasonable based on the actuarial 5-year survival rates of the subgroups in the same stage. The present study also showed that the classification of stage IV still requires further discussion.

Evaluation Studies as Topic↗
PubMed1998

Benign esophageal stricture caused by diffuse severe esophagitis presenting as ascending fibrosis: report of a case.

A 46-year-old Japanese man was referred to our hospital for treatment of an esophageal stricture. Esophageal cancer was suspected after detailed investigations, and a right transthoracic esophagectomy was performed. The resected specimen showed only nonspecific esophagitis with severe fibrous thickening in the submucosa, but no evidence of malignancy. Between 1906 and 1993, only 19 similar cases of benign esophageal strictures with fibrous thickening, excluding congenital and iatrogenic strictures, have been reported in Japan. These lesions occurred in the middle to lower third of the esophagus in 15 of 19 cases (78.9%), and 8 of the 19 patients (42.1%) were aged between 30 and 50 years. The interval between onset and hospital admission was short, being less than 1 year in 8 of the 12 patients for whom this information was available. Our patient demonstrated a disorder resembling the diffuse severe esophagitis described by Roth in 1974.

Biopsy↗
PubMed1998

Beneficial effects of renal transplantation on cardiovascular disorders in dialysis patients.

The present study was conducted to evaluate the impact of successful renal transplantation against the cardiovascular risk factors of patients on maintenance dialysis in whom cardiovascular accidents are the most common cause of death. A total of 74 renal transplant patients with grafts that had been functioning well for longer than 6 months after transplantation were examined before and 6-250 months after transplantation. The mean age was 34 years and the duration after transplantation was 104 +/- 66 months. An improvement in anemia from hemoglobin level of 9.0 to 13.6 g/dl and a decrease in mean systolic blood pressure from 157 +/- 24 to 135 +/- 14 mm Hg (P < 0.001) were observed after transplantation. An elevation in RV5 + SV1 levels by 0.6 mV on electrocardiogram (P = 0.042) was seen without any change in the cardiothorathic ratio on chest X-ray. Echocardiographic measurements of six recipients revealed great improvements in the left ventricular systolic dimension and thickness of the posterior wall of the left ventricle. Moreover, the ejection fraction and fractional shortening rose significantly from 59.4% +/- 16.3% to 75% +/- 8.1%, and from 30.6% +/- 9.2% to 44.8% +/- 7.9% (P = 0.017), respectively. These findings clearly show that successful renal transplantation can significantly improve the cardiovascular function of renal patients on maintenance dialysis.

Adolescent↗