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Biomedical subjects

Y Otani

Publications and source records attributed to Y Otani.

At least 37 records · Page 2Linked to original sources
PubMed2001

Cyclin D1 antisense oligonucleotide inhibits cell growth stimulated by epidermal growth factor and induces apoptosis of gastric cancer cells.

The cyclin D1 protein is one of the cell cycle regulators required for cell cycle progression through G1 phase to S phase. The cyclin D1-cyclin-dependent kinase (CDK) system is thought to control the cell cycle through mediating extracellular signals from mitogens, such as epidermal growth factor (EGF). In this study, we attempted to examine the therapeutic effect of cyclin D1 antisense oligonucleotides (AS/D1) on cell proliferation and apoptosis of the gastric cancer cell line MKN-74, in the presence and absence of EGF-stimulation. Evaluation of cell survival and DNA synthesis revealed that enhanced cell growth following EGF-stimulation was completely inhibited by a 24 h pre-incubation with 100 nM AD/D1. This inhibition was down to 19.3% compared with maximal DNA synthesis after stimulation with 3 nM EGF alone. Western blotting demonstrated that while EGF-stimulation led to cyclin D1 over-expression, AS/D1 inhibited cyclin D1 protein expression. We also demonstrated the induction of apoptosis in MKN-74 cells by AS/D1. In conclusion, EGF-stimulated MKN-74 cell proliferation was inhibited by AS/D1, which could overcome EGF-induced cyclin D1 over-expression. AS/D1 also affected cell survival by inducing apoptosis through cell cycle arrest following cyclin D1 depletion. Thus, AS/D1 may be a candidate for use as a novel cancer therapy specifically targeted against the over-expression of cyclin D1 enhanced by EGF in malignant cells.

Apoptosis↗
PubMed2001

UCN-01 (7-hydoxystaurosporine) inhibits in vivo growth of human cancer cells through selective perturbation of G1 phase checkpoint machinery.

Mechanisms underlying tumor sensitivity to the antitumor agent UCN-01 (7-hydroxystaurosporine) were examined in the nude mouse model using three human tumor xenografts, two pancreatic cancers (PAN-3-JCK and CRL 1420) and a breast cancer (MX-1). UCN-01 antitumor activity was evaluated in terms of relative tumor weights in treated and untreated mice bearing the tumor xenografts. The activity of cyclin-dependent kinase 2 (CDK2), levels of p21 and p27 proteins, pRb status and cell cycle were evaluated. Induction of p21 and apoptosis were also assessed immunohistochemically in CRL 1420. UCN-01 was administered intraperitoneally at a dose of either 5 or 10 mg / kg daily for 5 days followed by a further 5 injections after an interval of 2 days. UCN-01 significantly suppressed the growth of both pancreatic cancers, but was ineffective against MX-1. p21 protein expression was markedly induced in the UCN-01-sensitive pancreatic carcinoma xenografts at both doses, but p21 induction was only evident in the UCN-01-resistant MX-1 at 10 mg / kg. MX-1 exhibited CDK2 activity that was 6-fold higher than that of pancreatic cancer strains, which may explain the resistance of MX-1 to UCN-01 despite the induction of p21 at the dose of 10 mg / kg. The UCN-01-sensitive tumors exhibited G1 arrest and increased levels of apoptosis, changes not observed in resistant MX-1. In conclusion, it appears that a determining factor of in vivo UCN-01 sensitivity involves the balance of CDK2 kinase activity and p21 protein induction, resulting in augmented pRb phosphorylation, G1 cell cycle arrest and apoptosis.

Alkaloids↗
PubMed2001

The citrus flavonoid, nobiletin, inhibits peritoneal dissemination of human gastric carcinoma in SCID mice.

The flavonoid nobiletin (5,6,7,8,3',4'-hexamethoxyflavone), found in Citrus depressa Rutaceae, a popular citrus fruit in Okinawa, Japan, reportedly inhibits the production of pro-matrix metalloproteinase (proMMP)-1, 3, and 9 in rabbit synovial fibroblasts in vitro. In the present study, we demonstrated the inhibitory effects of nobiletin on the proliferation of the cancer cell line, TMK- 1, and its production of MMPs. In the SCID mouse model, we found that nobiletin inhibited the formation of peritoneal dissemination nodules from TMK-1. The enzymatic activity of MMP-9 expressed in culture medium obtained from a co-culture of TMK-1 and mouse fibroblastic cells was inhibited by nobiletin in a concentration-dependent manner. In the SCID mouse model, total weight of dissemination nodules was significantly lower in the treated group compared with the vehicle control group (0.07 g vs. 0.78 g, P = 0.0059). The total number of dissemination nodules was also significantly lower than in the vehicle control group (7.5 vs. 69.3 / body, P = 0.0001). These results suggest that nobiletin may be a candidate anti-metastatic drug for prevention of peritoneal dissemination of gastric cancer.

Animals↗
PubMed2001

Evidence for horizontal transfer of SsuDAT1I restriction-modification genes to the Streptococcus suis genome.

Different strains of Streptococcus suis serotypes 1 and 2 isolated from pigs either contained a restriction-modification (R-M) system or lacked it. The R-M system was an isoschizomer of Streptococcus pneumoniae DpnII, which recognizes nucleotide sequence 5'-GATC-3'. The nucleotide sequencing of the genes encoding the R-M system in S. suis DAT1, designated SsuDAT1I, showed that the SsuDAT1I gene region contained two methyltransferase genes, designated ssuMA and ssuMB, as does the DpnII system. The deduced amino acid sequences of M. SsuMA and M.SsuMB showed 70 and 90% identity to M.DpnII and M.DpnA, respectively. However, the SsuDAT1I system contained two isoschizomeric restriction endonuclease genes, designated ssuRA and ssuRB. The deduced amino acid sequence of R.SsuRA was 49% identical to that of R.DpnII, and R.SsuRB was 72% identical to R.LlaDCHI of Lactococcus lactis subsp. cremoris DCH-4. The four SsuDAT1I genes overlapped and were bounded by purine biosynthetic gene clusters in the following gene order: purF-purM-purN-purH-ssuMA-ssuMB-ssuRA++ +-ssuRB-purD-purE. The G+C content of the SsuDAT1I gene region (34.1%) was lower than that of the pur region (48.9%), suggesting horizontal transfer of the SsuDAT1I system. No transposable element or long-repeat sequence was found in the flanking regions. The SsuDAT1I genes were functional by themselves, as they were individually expressed in Escherichia coli. Comparison of the sequences between strains with and without the R-M system showed that only the region from 53 bp upstream of ssuMA to 5 bp downstream of ssuRB was inserted in the intergenic sequence between purH and purD and that the insertion target site was not the recognition site of SsuDAT1I. No notable substitutions or insertions could be found, and the structures were conserved among all the strains. These results suggest that the SsuDAT1I system could have been integrated into the S. suis chromosome by an illegitimate recombination mechanism.

Amino Acid Sequence↗
PubMed2001

Development of endoscopic surgery for the minimally invasive treatment of digestive and other diseases.

Minimally invasive surgery has rapidly changed the performance of surgical practice in a wide range of surgical specialities in the last decade of the 20th century. The marked progress in endoscopic surgery has been conducted especially in general and digestive surgery. The Department of Surgery, School of Medicine, Keio University has contributed to the development and establishment of endoscopic surgery in every subspeciality of general and digestive surgery. Our achievements include the development of original methods for laparoscopic wedge gastrectomy and endoscopic thyroidectomy, establishment of surgical techniques in endoscopic surgery for esophageal, gastric, colorectal and hepatobiliary diseases, and the introduction of robotics and tele-communicative technologies to endoscopic surgery.

Digestive System Surgical Procedures↗
PubMed2001

The characteristics of screened patients with abdominal aortic aneurysm.

BACKGROUND: Screening for abdominal aortic aneurysm (AAA) has not yet been established in Japan. We therefore report the characteristics of a screened population and discuss the implications of screening using ultrasound in Japan. METHODS: The subjects in our screening group were composed of 4428 participants who were 60 years of age or older. Aneurysm was detected in 16 cases, 15 males and 1 female, the detection rate being 0.4% in total and 0.9% in the males. We compare the characteristics of screened patients (n = 16) with non-screened patients operated on for abdominal aortic aneurysm (n = 166). RESULTS: There were no significant differences in the mean age or in the female ratio between the screened and non-screened groups (71 vs 70 y/o, 6% vs 13%, respectively). Solitary iliac aneurysms were significantly (p < 0.05) more frequent in the screened than in the non-screened group (19% vs 3%). The size of aneurysm in the screened group was significantly (p < 0.05) smaller compared with the non-screened group. Sixty-three per cent of the screened group and only 8% of the non-screened group had an aneurysm less than 40 mm in size. Aneurysm was palpable in only 31% of those of the screened group. There were no significant differences between the groups in the frequency of arteriosclerotic risk factors such as hypertension, ischaemic heart disease, diabetes mellitus, peripheral vascular disease and smoking habits. Surgical treatment was selected in 7 out of 16 screened patients. The remaining 9 patients with small-sized abdominal aortic aneurysms have been carefully followed up. CONCLUSIONS: Screening for abdominal aortic aneurysm using ultrasound is advisable especially for male participants and for the detection of iliac aneurysms. This screening procedure is useful for early detection because the screened aneurysm is generally small-sized and impalpable.

Aged↗
PubMed2001

[Combination chemotherapy of doxifluridine plus mitomycin C for colorectal lung metastasis--phase II study].

PURPOSE: We conducted a multi-center study to investigate the usefulness of a combination drug therapy with doxifluridine (5'-DFUR) and mitomycin C (MMC) in colorectal cancer patients with lung metastasis. PATIENT AND METHODS: Subjects were advanced/recurrent colorectal cancer patients with lung metastasis, who underwent concomitant drug administration with 533 mg/m2/day of 5'-DFUR orally and 4 mg/m2/day of MMC every 2 weeks intravenously. RESULTS: Of 84 patients registered, 54 patients who were evaluable for tumor response showed results such as: complete response, one; partial response, 4; no change, 30; and progressive disease, 19, corresponding to a response rate of 9.3%. The median survival period of 54 patients was long at 473 days. The median administration days of 5'-DFUR was 201.5 days and the median number of MMC administrations was 14, indicating a long administration period of the combined therapy. The incidence of adverse drug reactions (ADRs) was 37.2% which included thrombocytopenia, 16.7%, and leukocytopenia, 11.5%; only a few ADRs were grade 3 or over. CONCLUSIONS: While combined therapy with 5'-DFUR and MMC resulted in a low response rate, the regimen suggested a survival effect in the patients.

Adult↗
PubMed2001

Laparoscopic detection of sentinel lymph nodes in gastrointestinal cancer: a novel and minimally invasive approach.

Although the sentinel node (SN) concept has been validated in malignant melanoma and breast cancer, the application of this concept for other solid tumors, including gastrointestinal (GI) cancer, is still controversial. We have demonstrated the feasibility of radioguided SN mapping during laparotomy in patients with esophageal, gastric, and colorectal cancers. In 188 patients, the SNs identified by this technique had an overall diagnostic accuracy of 96% for regional lymph node metastasis. Aberrant drainage sites that have been called skip metastasis from the primary lesion were detectable using this method. More recently, we have undertaken SN mapping during laparoscopic surgery. A combination of radiotracer and blue dye optimized the identification of SNs that drained GI cancers. Our preliminary data indicate that laparoscopic mapping of the SN is a sensitive intraoperative technique for identifying lymph node micrometastasis, and we believe that it will become an important component of a minimally invasive approach to early-stage GI cancers.

Colonic Neoplasms↗
PubMed2001

[Clinical significance of sentinel node navigation surgery in the treatment of early gastric cancer].

Radical lymphadenectomy is the standard surgical approach even for early-stage gastric cancer with a relatively low incidence of lymph node metastasis because of the limited sensitivity of diagnostic imaging to detect micrometastasis in regional lymph nodes. The sentinel node (SN) concept is one topic among novel diagnostic procedures for micrometastasis. The SN is defined as the first draining node from the primary lesion and it would be the first site of micrometastasis. SN biopsy has been clinically validated and applied for the surgical treatment of malignant melanoma and breast cancer. Although the feasibility of this technique in other solid tumors including gastric cancer is still controversial, there are several reports demonstrating the diagnostic significance of SN mapping in early gastric cancer. We have established radio-guided SN mapping for early gastric cancer, and the diagnostic accuracy using this procedure in cT1N0 cases reached 98%. The radio-guided method allows us to detect the SN in endoscopic surgery quantitatively and reproducibly. Validation of the SN concept in gastric cancer in a multi-centric clinical trial is essential for clinical application of this procedure, including the establishment of a novel, minimally invasive approach for early-stage gastric cancer.

Humans↗
PubMed2000

Granulocyte-macrophage colony-stimulating factor upregulates matrix metalloproteinase-2 (MMP-2) and membrane type-1 MMP (MT1-MMP) in human head and neck cancer cells.

Matrix metalloproteinase-2 (MMP-2) and membrane type 1-MMP (MT1-MMP) play an important role in the invasion and metastasis of head and neck squamous cell carcinoma (HNSCC), but the mechanism of their regulation is not clearly understood. Recently, granulocyte-macrophage colony-stimulating factor (GM-CSF) has been shown to be associated with cancer invasion and metastasis. We hypothesized that GM-CSF may upregulate MMP-2 and/or MT1-MMP expression in HNSCC cells, and may thereby influence their ability to invade and metastasize. We studied the effects of GM-CSF on the production of MMP-2 and MT1-MMP in HNSCC cell lines SAS and HSC-2. Gelatin zymography of conditioned media derived from HNSCC cells revealed a major band of 68 kDa, which was characterized as proMMP-2. GM-CSF stimulated the production of proMMP-2 in both cell lines in a dose-dependent manner. Treatment with 50 ng/ml GM-CSF for 24 h increased the proMMP-2 activity 3.4-fold in SAS cells and 2.3-fold in HSC-2 cells compared with untreated controls. Northern blot analyses demonstrated that GM-CSF led to elevated mRNA levels of MMP-2 and MT1-MMP in both cell lines. The results identify GM-CSF as a regulator of MMP-2 and MT1-MMP expression in certain types of HNSCC, and suggest that GM-CSF may contribute to the invasiveness of HNSCC through the regulation of MMP-2 and MT1-MMP expression.

Cell Division↗
PubMed2000

Activation of matrix metalloproteinase-2 in head and neck squamous cell carcinoma: studies of clinical samples and in vitro cell lines co-cultured with fibroblasts.

We undertook this present study to investigate the activation of matrix metalloproteinase-2 (MMP-2) in human head and neck squamous cell carcinomas (HNSCC) tissues and cell lines. Gelatinolytic activities of active MMP-2 were significantly higher in carcinoma samples than in normal portions. Furthermore, the activation ratio of proMMP-2 significantly correlated with cervical lymph node metastasis. In vitro studies revealed an HNSCC cell line, HEp-2, to produce neither the pro form nor the active form of MMP-2, but human fibroblasts were found to produce proMMP-2. However, coculture of HEp-2 cells with fibroblasts resulted in the production of not only proMMP-2 but also activeMMP-2 in the culture medium. Northern blot analysis revealed a stronger expression of membrane-type 1 matrix metalloproteinase (MT1-MMP),which is a specific activator of MMP-2, mRNA in HEp-2 cells than in fibroblasts. These results suggest the activation of proMMP-2 as an important event in the process of HNSCC metastasis. They also suggest MMP-2 is secreted in its pro form by stromal fibroblasts surrounding the cancer cells and activated by MT1-MMP localized on the cancer cells.

Aged↗
PubMed2000

Feasibility of a novel weekday-on/weekend-off oral UFT schedule as postoperative adjuvant chemotherapy for colorectal cancer. UFT Compliance Study Group, Kanagawa, Japan.

PURPOSE: When oral anticancer agents are used for adjuvant chemotherapy of colorectal cancer, compliance and feasibility become issues because of the long treatment time. Appropriate studies of these issues are lacking. We investigated compliance and feasibility during a weekday-on/weekend-off schedule of oral UFT (uracil-tegafur) over a period of 1 year administered as adjuvant chemotherapy to patients with colorectal cancer. PATIENTS AND METHODS: A UFT dose of 600 mg/day was prescribed according to a weekday-on/weekend-off schedule to 87 patients after potentially curative resection. Compliance was investigated in three ways: physician interview, patient self-report, and chemical analysis of urine. The results were compared with the dose prescribed. Feasibility was evaluated on the basis of two indices: relative performance (RP), which was the ratio of the actual total dose taken to the total dose planned, and individual dose intensity (IDI), which was the ratio of the actual dose taken to the dose planned during a given period. RESULTS: The compliance assessed by physician interview and by patient self-report conformed well with the prescribed dose, the rate of agreement among the three compliance measures being more than 94%. Chemical analysis of urine in 38 of the patients revealed that they were actually taking the drug. The RP was 0.72, and the IDI was 0.8. CONCLUSION: From these results, the feasibility of the weekday-on/weekend-off schedule was judged to be good. It is suggested that the feasibility would be even better if the dose of UFT was set according to body surface area.

Administration, Oral↗
PubMed2000

Gastrointestinal stromal tumors treated by laparoscopic surgery: report of three cases.

Three cases of gastrointestinal stromal tumors (GIST) were treated by a laparoscopic wedge resection of the stomach. The tumor characteristics were confirmed to be nonepithelial, nonlymphomatous, nonmyogenic, and nonneurogenic gastrointestinal neoplasms with an uncertain origin which were CD34-positive and actin- and S-100-negative. The malignant potential was estimated based on the mitotic figures and growth rates. The results suggest that laparoscopic surgery is an adequate strategy for gastric submucosal tumors including GIST, and also indicates this technique to be a curative, safe, and minimally invasive procedure for both diagnosis and treatment.

Actins↗
PubMed2000

Jejunal limb obstruction caused by a cholesterol stone 15 years after a total gastrectomy and 20 years after a cholecystectomy: report of a case.

We present herein the rare case of a 74-year-old woman found to have jejunal limb obstruction caused by a cholesterol stone 15 years after a total gastrectomy with Roux-en-Y anastomosis, and 20 years after a cholecystectomy. The patient complained of repeated episodes of upper abdominal distress on three separate occasions over a period of 20 months, and jejunal limb obstruction was diagnosed by abdominal computed tomography scanning and (99m)Tc scintigraphy. Surgery revealed a stone incarcerated in the jejunal limb, where the anastomosis had become slightly stenotic. The removed stone was 3.5 cm in diameter and was subsequently demonstrated to be a cholesterol stone by chemical analysis. This report is thought to be the first to describe jejunal limb obstruction caused by a gallstone incarcerated in the jejunal limb after a total gastrectomy in a patient with a history of cholecystectomy.

Acute Disease↗
PubMed2000

Thoracoscopic treatment of primary chylopericardium.

The development of video-assisted thoracoscopy has changed the practice of thoracic surgery. This report describes a 20-year-old man who successfully underwent thoracoscopic thoracic duct ligation and partial pericardiectomy for primary chylopericardium. We recommend a right-sided thoracoscopic approach to the thoracic duct in the lower thoracic cavity.

Adult↗