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Michiya Kobayashi

Publications and source records attributed to Michiya Kobayashi.

At least 19 recordsLinked to original sources
PubMed2007

[Case of multiple (at least 28 lesions) gastric intramural metastases from gastric cancer].

A 76-year-old man was admitted for treatment of gastric cancer that causing anorexia. Endoscopy showed the stenosis in the antrum of the stomach and multiple small nodules with erosion from the upper body to the corpus of the stomach. Total gastrectomy with Roux-en-Y reconstruction was performed. On the resected specimen, there were at least 28 nodules with erosion in the submucosal layer of the entire stomach. The lesions had no continuity with one another and were the same histological type, poorly differentiated adenocarcinoma. We diagnosed these lesions as intramural metastases of gastric cancer.

Adenocarcinoma↗
PubMed2006

Efficacy of adjuvant immunochemotherapy with polysaccharide K for patients with curative resections of gastric cancer.

Non-specific immunopotentiators, such as polysaccharide K (PSK), also known as OK-432, induce anti-tumor effects via immunological responses. The efficacy of combination immunochemotherapy using these immunopotentiators has been examined by multiple previous studies. The survival benefits of immunochemotherapy for patients with curative resections of gastric cancers are not widely accepted. To clarify this issue, we performed a meta-analysis to evaluate the effect of immunochemotherapy on survival in patients with curative resections of gastric cancer. For this study, we compared the results of chemotherapy and immunotherapy using the biological response modifier PSK as an immunopotentiator. The meta-analysis included 8,009 patients from eight randomized controlled trials after central randomization. The overall hazard ratio for eligible patients was 0.88 (95% confidence interval, 0.79-0.98; P = 0.018) with no significant heterogeneity [chi (2)(8) for heterogeneity = 11.7; P = 0.16]. The results of this meta-analysis suggest that adjuvant immunochemotherapy with PSK improves the survival of patients after curative gastric cancer resection.

Adjuvants, Immunologic↗
PubMed2006

Autopsy study of anatomical features of the posterior gastric artery for surgical contribution.

AIM: To investigate features of the posterior gastric artery (PGA) with respect to incidence, location and size by using autopsy subjects. METHODS: Autopsies were performed on 72 cadavers of adults with no history of abdominal operations. The localization of the PGA, the distance between the root of the splenic artery and the origin of the PGA, and the external diameter of the PGA were examined. RESULTS: The PGA was recognized in all patients. In 70 (97.2%) cadavers, the PGA branched from the splenic artery, and one female in this group had two PGAs. In 1 (1.4%) patient, the PGA originated from the root of the celiac trunk and in another (1.4%) patient, the PGA branched from the superior polar artery. Overall, the PGA extended for a length of 5.8-12.2 (mean, 8.4) cm from the root of the splenic artery, and the external diameter of the PGA was 1.2-3.2 (mean, 2) mm. CONCLUSION: The anatomical features of the PGA can be readily observed and characterized by autopsy. This study has provided valuable information on the features of the PGA useful in the planning of surgical treatment.

Aged↗
PubMed2006

Pharmacokinetic study of paclitaxel in malignant ascites from advanced gastric cancer patients.

AIM: To examine the paclitaxel concentrations in plasma and ascites after its intravenous administration in patients with ascites due to peritonitis carcinomatosa resulting from advanced gastric cancer. METHODS: Two patients with ascites due to peritonitis carcinomatosa resulting from gastric cancer were included in this study. The paclitaxel concentrations in plasma and ascites were investigated for 72 h in case 1 and 168 h in case 2 after intravenous administration. RESULTS: The paclitaxel concentration in plasma peaked immediately after administration, followed by rapid decrease below the threshold value of 0.1 micromol (85 ng/mL) within 24 h. In contrast,the paclitaxel concentration in ascites increased gradually for 24 h after administration to a level consistent with the level found in plasma. After 24 h the level of paclitaxel in ascites and plasma became similar, with the optimal level being maintained up to 72 h following administration. CONCLUSION: The concentration of paclitaxel in ascites is maintained within the optimal level for the treatment of cancer cells for up to 72 h after intravenous administration. Paclitaxel is a promising drug for the treatment of malignant ascites of gastric cancer.

Antineoplastic Agents, Phytogenic↗
PubMed2006

STI571 (Glivec) suppresses the expression of vascular endothelial growth factor in the gastrointestinal stromal tumor cell line, GIST-T1.

AIM: To estimate whether STI571 inhibits the expression of vascular endothelial growth factor (VEGF) in the gastrointestinal stromal tumor (GIST) cells. METHODS: We used GIST cell line, GIST-T1. It has a heterogenic 57-bp deletion in exon 11 to produce a mutated c-KIT, which results in constitutive activation of c-KIT. Cells were treated with/without STI571 or stem cell factor (SCF). Transcription and expression of VEGF were determined by RT-PCR and flow cytometry or Western blotting, respectively. Activated c-KIT was estimated by immunoprecipitation analysis. Cell viability was determined by MTT assay. RESULTS: Activation of c-KIT was inhibited by STI571 treatment. VEGF was suppressed at both the transcriptional and translational levels in a temporal and dose-dependent manner by STI571. SCF upregulated the expression of VEGF and it was inhibited by STI571. STI571 also reduced the cell viability of the GIST-T1 cells, as determined by MTT assay. CONCLUSION: Activation of c-KIT in the GIST-T1 regulated the expression of VEGF and it was inhibited by STI571. STI571 has antitumor effects on the GIST cells with respect to not only the inhibition of cell growth, but also the suppression of VEGF expression.

Antineoplastic Agents↗
PubMed2006

Preoperative assessment of vascular anatomy of inferior mesenteric artery by volume-rendered 3D-CT for laparoscopic lymph node dissection with left colic artery preservation in lower sigmoid and rectal cancer.

AIM: To determine the distance between the branching point of the left colic artery (LCA) and the inferior mesenteric artery (IMA) by computed tomography (CT) scanning, for preoperative evaluation before laparoscopic colorectal operation. METHODS: From February 2004 to May 2005, 100 patients (63 men, 37 women) underwent angiography performed with a 16-scanner multi-detector row CT unit (Toshiba, Aquilion 16). All images were analyzed on a workstation (AZE Ltd, Virtual Place Advance 300). The distance from the root of the IMA to the bifurcation of the LCA was measured by curved multi-planar reconstruction on a workstation. RESULTS: The IMA could be visualized in all the cases, but the LCA was missing in two patients. The mean distance from the root of the IMA to the root of the LCA was 42.0 mm (range, 23.2-75.0 mm). There were no differences in gender, arterial branching types, body weight, height, and body mass index. CONCLUSION: Volume-rendered 3D-CT is helpful to assess the vascular branching anatomy for laparoscopic surgery.

Adult↗
PubMed2006

Benefits of early postoperative jejunal feeding in patients undergoing duodenohemipancreatectomy.

AIM: To study whether early postoperative enteral nutrition reduces the incidence of complications and/or improves nutritional status following duodenohemipancreatectomy (DHP). METHODS: We studied 39 patients who underwent DHP for a peri-ampullary mass. Twenty-three patients received total parental nutrition and then started to have an oral intake of nutrition between postoperative day (POD) 7 and 14 [late postoperative enteral nutrition (LPEN) group]. Sixteen patients started to have enteral feeding through a jejunostomy catheter the day after the operation [early postoperative enteral nutrition (EPEN) group]. The incidence of complications and laboratory data at the early postoperative stage were studied in comparison between LPEN and EPEN groups. RESULTS: Serum levels of albumin and total protein in the EPEN group were significantly higher than those in the LPEN group. The loss of body mass index was significantly suppressed in the EPEN group as compared to the LPEN group. The lymphocyte count decreased immediately after the operation was restored significantly faster in the EPEN group than in the LPEN group. The EPEN group showed significantly fewer incidences of postoperative pancreatic fistulas, as well as a significantly shorter length of hospitalization than the LPEN group. There were no significant differences in the incidences of other postoperative complications between the two groups, such as delayed gastric emptying, surgical site infection, cholangitis, and small bowel obstruction. CONCLUSION: EPEN is a safe and beneficial opportunity for patients who have undergone DHP for a peri-ampullary mass.

Adult↗
PubMed2006

Helicobacter pylori CagA status associated with gastric cancer incidence rate variability in Costa Rican regions.

BACKGROUND: We evaluated several risk factors for gastric cancer in Costa Rican regions having contrasting gastric cancer incidence rates, despite the small dimensions of the country. METHODS: A total of 180 dyspeptic patients were classified into two groups according to the gastric cancer incidence (GCI) rate in their Costa Rican region: group A, with a high GCI rate (n = 91) and group B, with a low GCI rate (n = 89). Helicobacter pylori infection was detected by rapid urease test, Gram staining, and histological observation. Antral and corpus specimens were obtained to assess the grade of inflammation, topography of gastritis, gastric atrophy, and intestinal metaplasia by histological examination. Serum CagA antibody was measured by an antigen-specific enzyme-linked immunosorbent assay. RESULTS: There was no significant difference in H. pylori prevalence between groups A (73%) and B (63%); however, serum CagA antibody was more frequently detected in group A (79%) than in group B (54%) [P = 0.02; odds ratio (OR), 2.68]. Among patients under 60 years of age, serum CagA antibody was even more frequently detected in group A (81%) than in group B (49%) (P < 0.01; OR, 4.50). The prevalence of corpus-predominant gastritis, atrophic gastritis, and moderate/severe grades of neutrophilic infiltration was higher in serum CagA antibody-positive patients than in CagA antibody-negative patients (P = 0.003, 0.04, and 0.002, respectively). CONCLUSIONS: Infection with H. pylori possessing the cagA gene is associated with the development of severe gastric damage such as gastric atrophy, leading to gastric cancer, and probably influences the differences in GCI between Costa Rican regions.

Adult↗
PubMed2006

Complete remission of recurrent gastrointestinal stromal tumors after treatment with imatinib: report of a case.

A 49-year-old man underwent partial resection of the jejunum for an abdominal tumor, which was histologically confirmed to be a gastrointestinal stromal tumor (GIST). Immunohistochemistry revealed that the tumor cells were positive for c-kit, p52, and MIB-1. He underwent resection of a total of 83 recurrent tumors over the next 36 months. A computed tomography (CT) scan done a few months later showed multiple tumor recurrences. The patient was started on imatinib mesylate 400 mg/day, and 3 months later, a CT image showed an increase in tumor size but a decrease in tumor density. Subsequent CT scans showed a marked decrease in tumor size 3 months later and no evidence of tumor recurrence 9 and 12 months after the commencement of imatinib treatment. The patient remains in complete remission 31 months after the start of treatment.

Antineoplastic Agents↗
PubMed2006

Scanning electron microscopic study of the three-dimensional structure of the collagen sheath surrounding cancer cells after single high-dose irradiation.

The effect of single high-dose irradiation on collagen networks in tumor cells was examined by scanning electron microscopy. MM46 tumor cells were transplanted into C3H/He mice and locally irradiated with a 30 Gy dose (6 MeV) 7-8 days posttransplantation. Mice were killed at various time points postirradiation, and tumor tissues were excised and fixed. After 2 N NaOH maceration, tissues were washed and stained with 1% tannic acid. They were then postfixed with 1% OsO4, dehydrated, and dried. The tissues were coated with gold, and the three-dimensional structure of the collagen fibers was observed using scanning electron microscopy. In the control group, the chambers formed by collagen fibers were larger on days 7 and 14 than those on days 1 and 3. In the irradiated group, the chambers were largest and most irregular in shape on day 7. The chamber size had decreased approximately 50% by day 14, and there was evidence of tumor cell regeneration. In addition, several fenestrations in the chamber wall developed in the irradiated group. Fenestrations in the collagen chamber walls surrounding tumor cells might allow transfer of metabolites that provide nutrition to the tumor cells, leading to their regeneration.

Animals↗
PubMed2006

A feasibility study of sequential paclitaxel and S-1 (PTX/S-1) chemotherapy as postoperative adjuvant chemotherapy for advanced gastric cancer.

BACKGROUND: The most frequent recurrence pattern of advanced gastric cancer is peritoneal dissemination. We investigated the safety of and compliance with sequential chemotherapy consisting of paclitaxel and S-1, both of which are effective in the treatment of peritoneal dissemination. METHODS: The patients in the study all had histologically proven gastric cancer, classified according to the TNM and the Japanese criteria for gastric cancer as T3-4, N0-2, P0, H0 M0, and CY0-1. In all patients, standard gastrectomy of more than a D2 dissection was performed. A dose of 80 mg/m2 of paclitaxel was administered for three courses. One course comprised weekly administration for 3 weeks, followed by a 1-week rest, except for the first course (following S-1 administration at 80 mg/m2 body surface area), in which paclitaxel was administered for only 2 weeks, followed by a 1-week rest. S-1 was administered from day 78 for four courses, with one course comprising 2 weeks' administration followed by a 1-week rest. Fifty patients received paclitaxel chemotherapy. The median age was 62.5 years overall; among the 34 male patients it was 65.5 years, and among the female patients it was 48.0 years. RESULTS: The patient compliance rate was 84%. There were no cases of grade 4 hematological toxicity during either paclitaxel or S-1 treatment. With respect to nonhematological toxicities, there was one case of grade 3 neuropathy during the course of paclitaxel treatment and one case of grade 3 diarrhea during the course of S-1 treatment. These patients recovered and completed the scheduled treatment regimen. CONCLUSION: Sequential chemotherapy of paclitaxel and S-1 as postoperative adjuvant chemotherapy for advanced gastric cancer is feasible.

Adult↗
PubMed2006

A simple biangulation stapling technique for large anastomoses in gastric surgery.

We describe here a new technique for performing the large anastomosis between the jejunal pouch and the remnant stomach in patients undergoing proximal gastrectomy with jejunal pouch interposition. The biangulation method described in this report is a simpler technique than the existing triangulation anastomosis technique, requiring only two applications of a linear stapler. One row of staples forms the posterior wall of the anastomosis and the other forms the anterior wall. When used for jejunal pouch reconstruction after proximal gastrectomy in 12 cases of early gastric cancer, no evidence of anastomotic leakage or stenosis was apparent from barium meal studies or endoscopic examination. We find this biangulation technique to be a simple and safe procedure that is ideal for anastomoses of large diameter.

Anastomosis, Surgical↗
PubMed2006

Clinicopathological features and medical management of intraductal papillary mucinous neoplasms.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMN) are a clinicopathological entity that is being diagnosed with increasing frequency. However, the best approach to medical management of IPMN needs to be clarified. The aim of the present study was to identify preoperative features that may be predictors of malignant IPMN, and to define the medical management of IPMN of the pancreas. METHODS: A total of 23 patients who underwent surgical resection for IPMN of the pancreas at Kochi Medical School between 1982 and 2004 were examined. Multivariate Cox regression analysis was used to identify factors independently associated with IPM carcinoma. RESULTS: Among the 23 patients, 12 had IPMN adenoma, three had borderline IPMN, four had IPMN with carcinoma in situ, and four had IPMN with invasive carcinoma. In multivariate analysis, elevated serum carcinoembryonic antigen (CEA) and carbohydrate antigen (CA) 19-9 levels were found to be preoperative predictors of malignant IPMN. These results suggest that the following IPMN of the pancreas should be resected: (i) IPMN of the pancreas situated in the main duct; (ii) IPMN located in the branch duct if the size of the cystic lesion is >30 mm and the mural nodules are >5 mm in height by endoscopic ultrasound (EUS); and (iii) the diameter of the main pancreatic duct is >10 mm by endoscopic retrograde pancreatography (ERP). Careful observation of patients with branch-type IPMN with small cysts and/or without mural nodules is recommended as a management strategy. CONCLUSION: The present study reinforces the need for immediate surgical resection of malignant IPMN and suggests indicators for IPMN that should assist physicians in making decisions on treatment options.

Adenocarcinoma, Mucinous↗
PubMed2006

Non-cystic solid-pseudopapillary tumor of the pancreas showing nuclear accumulation and activating gene mutation of beta-catenin.

Solid-pseudopapillary tumor (SPT) is an unusual pancreatic neoplasm that is characterized by a mixture of solid and cystic components and a fibrous capsule. Recently, the tumorigenesis of SPT has been reported to be associated with gene mutations of beta-catenin, which is a molecule participating in the Wnt signaling pathway. Reported herein is the case of a 53-year-old woman with SPT. The tumor, approximately 3 cm in diameter in the pancreas body, had a clear margin and central calcification but had neither a cystic component nor fibrous capsule. Several lines of pathological findings in the surgically resected specimen indicated SPT: (i) pseudopapillary proliferation of eosinophilic polygonal cells with oval nuclei; (ii) positive expression of several marker molecules indicating differentiation into acinar and endocrine cells; and (iii) zymogen granule-like structures in the cytoplasm on electron microscopy. Further, the tumor cells had intense nuclear accumulation of beta-catenin and an activating mutation, (34)Gly(GGA) to Arg(AGA), in exon 3 of the beta-catenin gene, as previously reported in most SPT. These findings suggest that association of the beta-catenin phenotype with development of the rare phenotype of SPT, a non-cystic and unencapsulated tumor, is unlikely.

Biomarkers, Tumor↗
PubMed2006

A beneficial interaction between imipenem and piperacillin possibly through their renal excretory process.

In order to assess the beneficial mechanism of the concomitant use of imipenem (IPM) with piperacillin (PIPC) for the treatment of serious infectious diseases such as sepsis, the effects of PIPC on the uptake of IPM by rat renal cortical slices and on the plasma concentrations of IPM after intravenous infusion to rabbits were studied. The uptake of IPM by the rat renal cortical slices was significantly inhibited by p-aminohippurate, probenecid and PIPC whereas the uptake of PIPC by the slices was slightly decreased in the presence of IPM. When IPM was administered together with PIPC by 1-h infusion, the plasma concentrations of IPM were significantly increased during the infusion. These results imply that PIPC possibly interferes with the renal transport of IPM mediated by an organic anion transporter across the renal basolateral membranes, which leads to a longer period above the minimum inhibitory concentrations of IPM.

Animals↗
PubMed2006

Characterization of intestinal absorption and enterohepatic circulation of mycophenolic Acid and its 7-O-glucuronide in rats.

To assess the mechanism of gastrointestinal disorders by mycophenolate mofetil (MMF), the intestinal absorption and enterohepatic circulation of mycophenolic acid (MPA), an active metabolite of MMF, and its 7-O-glucuronide (MPAG) were investigated using rat intestinal loops and a linked-rat model. The stability of MPAG in the intestinal fluids, the toxicity of MPA and MPAG to intestinal mucosa, and biliary excretion of MPAG in rats with acute renal failure (ARF) were also characterized. MPA was rapidly and extensively absorbed from the rat intestine whereas MPAG was much less absorbable. When MPA was administered intravenously to bile-donor rats, 1.2% of dose was excreted in bile of receiver rats exclusively as MPAG during 4 h. MPAG was minimally deconjugated in the intestinal fluids. MPAG, but not MPA, significantly enhanced the release of lactate dehydrogenase from intestinal mucosa. When MPA was intravenously administered to ARF rats, the biliary excretion of MPAG significantly increased, compared with that in normal rats. These results demonstrated that MPAG accumulated in the intestinal lumen following biliary excretion and exerted some toxic effect on the intestinal mucosa. It was also suggested that enterohepatic circulation of MPAG under renal dysfunction increased the risk of gastrointestinal disorders due to MPAG.

Acute Kidney Injury↗