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Masaki Kitajima

Publications and source records attributed to Masaki Kitajima.

At least 91 records · Page 5Linked to original sources
PubMed2005

Effect of dietary anti-urease immunoglobulin Y on Helicobacter pylori infection in Mongolian gerbils.

BACKGROUND AND AIM: Helicobacter pylori is known to be a major pathogenic factor in the development of gastritis, peptic ulcer disease and gastric cancer. Recently, chicken egg yolk immunoglobulin Y (IgY) has been recognized as an inexpensive antibody source for passive immunization against gastrointestinal infections. The present study was designed to investigate the effect of anti-urease IgY on H. pylori infection in Mongolian gerbils. METHODS: H. pylori-infected Mongolian gerbils were administered a diet containing anti-urease IgY, with or without famotidine (F). After 10 weeks, bacterial culture and measurement of the gastric mucosal myeloperoxidase (MPO) activity were performed. In a second experiment, another group of gerbils was started on a diet containing F + IgY a week prior to H. pylori inoculation. After 9 weeks, these animals were examined. RESULTS: In the H. pylori-infected gerbils, there were no significant differences in the level of H. pylori colonization among the different dietary and control groups. However, the MPO activity was significantly decreased in the H. pylori group administered the F + IgY diet compared with that in the H. pylori group administered the IgY, F, or control diet. Furthermore, in the gerbils administered the F + IgY diet prior to the bacterial inoculation, inhibition of H. pylori colonization and suppression of the elevated gastric mucosal MPO activity were observed. CONCLUSIONS: Oral administration of urease-specific IgY not only inhibited H. pylori disease activity in H. pylori-infected gerbils, but also prevented H. pylori colonization in those not yet infected. These encouraging results may pave the way for a novel therapeutic and prophylactic approach in the management of H. pylori-associated gastroduodenal disease.

Animals↗
PubMed2005

Is chemoradiation effective or harmful for stage VI gastric cancer patients?

We aim to clarify beneficial effect of pre-operative radiation with chemotherapy in highly advanced gastric cancer patients, evaluating histological response, toxicity and patients' quality of life (QOL). We used pre-operative radiation with S-1 and low-dose cisplatin to treat 8 patients with highly advanced gastric cancer (clinical stage IV) in a pilot study. Clinical staging after therapy showed 5 PRs (partial response), 2 NCs (no change), and 1 PD (partial disease) following evaluation of the primary tumor and suspicious metastatic lesions in the lymph nodes, esophagus, liver, and peritoneum, for a response rate of 62.5% (5/8 cases). Of 8 patients, 6 underwent surgery, and 2 of these 6 patients had a histologically complete response (grade 3 effect) and 3 patients had a partial response (grade 2 effect), suggesting that a high histological response (5/6 cases; 83.3%) is expected by the chemoradiation. The survival analysis showed that 5 out of the 8 patients died within 10 months after initiating therapy, while 3 patients are alive without recurrence at 15, 18, and 30 months after therapy, suggesting a relatively good outcome for clinical stage IV gastric cancer. All cases showed grade 2-4 bone marrow suppression toxicity and/or grade 0-2 gastro-intestinal toxicity, while 5 out of 8 patients (62.5%) showed improvement in appetite loss at the end of the therapy, indicating that the patients' quality of life (QOL) was preserved. Chemoradiation may be a powerful regimen for obtaining histological response with tolerable toxicity and improved QOL in highly advanced gastric cancer patients.

Adult↗
PubMed2005

[Recent studies of sentinel lymph node. Multicenter prospective clinical trials of SN biopsy for gastric cancer].

The sentinel node (SN) is defined as the first draining node from the primary lesion, and it has proven to be a good indicator of the metastatic status of regional lymph nodes in solid tumors. Recently, the validity of the SN concept in gastric cancer has been demonstrated by a number of single institutional studies, and prospective multi-center trials are presently ongoing. The Gastric Cancer Surgical Study Group of the Japan Clinical Oncology Group (JCOG) organized a multi-center prospective study of SN mapping by the dye-guided method using subserosal injection of indocyanine green. If the JCOG study reveals favorable results, in terms of false-negative rates, the dye-guided method will be utilized as a routine practice for open surgery in a wide range of institutions. If not, we will need to consider introduction of radioguided method or add further technical improvements, even for open surgery. A study group in the Japan Society of Sentinel Node Navigation Surgery is also conducting a multi-center prospective trial of SN mapping by a dual tracer method with blue dye and radio-active colloid. Even if the SNNS study demonstrates acceptable detection rates and low false-negative rates, we need to conduct a feasibility study of laparoscopic SN mapping for gastric cancer as the next step. The results of these clinical trials should provide useful perspectives on the future direction of SN navigation surgery for gastric cancer.

Clinical Trials as Topic↗
PubMed2005

New endoscopic treatments for gastroesophageal reflux disease.

This article reviews the available endoscopic treatments for gastroesophageal reflux disease (GERD). Plicating gastric folds methods, like Bard's EndoCinch method (Endoscopic Gastroplication, ELGP method), NDO Surgical's Full-thickness Plicator method, and Wilson-Cook Medical's Endoscopic Suturing Device (ESD) method, are used to form new plications in the cardia. Alternatively, thermal tissue remodeling/neurolysis methods, like Curon Medical's Stretta System, can be used to denature the muscular layer of the lower esophageal sphincter (LES) region. Finally, bulking injection methods, like Boston Scientific's Enteryx Procedure and Medtronic's Gatekeeper Reflux Repair System, can be used to insert a foreign body into the LES region. All six methods resulted in the improvement of symptoms and acid reflux, but only the bulking injection methods caused an improvement of the manometric findings. Nevertheless, the improvement of symptoms and acid reflux seems to be much more important than the improvement of the manometric findings. The overall discontinuation of proton-pump inhibitor (PPI) use was about 70%. Thus, endoscopic treatments for GERD are still in the development phase. The efficacy, safety, durability, cost-effectiveness, indications, and possible combination with other treatments must be thoroughly assessed in randomized controlled trials. If the usefulness of endoscopic treatment is confirmed, however, a new minimally invasive treatment strategy for GERD will have been established.

Endoscopy, Gastrointestinal↗
PubMed2005

Expression of basic fibroblast growth factor is associated with a good outcome in patients with squamous cell carcinoma of the esophagus.

Angiogenesis is an essential step in tumor growth and metastasis, but rather than being controlled by means of a simple mechanism, the control of tumor angiogenesis may be mediated by several angiogenic factors. We investigated the expression of basic fibroblast growth factor (b-FGF) and platelet-derived endothelial cell growth factor (PD-ECGF) in squamous cell carcinoma of the esophagus in order to clarify the mechanism of angiogenesis. Expression of b-FGF and PD-ECGF was immunohistochemically investigated in tissue specimens from the tumors of 79 patients with squamous cell carcinoma of the esophagus who underwent curative esophagectomy without preoperative chemotherapy or radiation therapy, and the relationship between expression of b-FGF/PD-ECGF, microvessel density (MVD), and clinicopathological background factors was assessed. Tumor cells that expressed b-FGF were found in 41 patients (51.9%), and tumor cells that expressed PD-ECGF were found in 57 patients (72.2%). Although the mean vascular density (47.9/mm(2)) of b-FGF-positive tumors was significantly lower than that (67.2/mm(2)) of b-FGF-negative tumors (p=0.014), the difference between the 56.0/mm2 in PD-ECGF-positive tumors and 60.3/mm2 in PD-ECGF-negative tumors was not significant. Although the survival rate of patients with b-FGF-positive tumors was significantly higher than those with b-FGF-negative tumors (p=0.033), there was no significant difference between the survival rates of patients with PD-ECGF-positive and -negative tumors (p=0.580). Expression of b-FGF may be associated with promotion of angiogenesis and a good prognostic factor in squamous cell carcinoma of the esophagus.

Adult↗
PubMed2005

TSU-68 (SU6668) inhibits local tumor growth and liver metastasis of human colon cancer xenografts via anti-angiogenesis.

A number of receptor tyrosine kinases (RTKs) are involved in angiogenesis. TSU-68 (SU-6668) was developed as an inhibitor of RTKs involved in VEGF, bFGF and PDGF signaling, which then inhibits endothelial cell proliferation. We investigated the antitumor effects of TSU-68 against human colon cancer xenografts in male SCID mice and its anti-angiogenic activity using a dorsal air-sac (DAS) assay. TSU-68 was administered orally at a dose of 200 mg/kg twice daily. Mice bearing human colon carcinoma, HT-29, or WiDr xenografts were treated for 16 days. To determine the effect on hepatic metastasis, cell suspensions of HT-29 or WAV-I were injected into the spleen of mice on day 0, and mice treated for 28 days starting from day 1. For the DAS assay, HT-29, WiDr or WAV-I cells suspended in PBS at 2 x 10(7) cells/Millipore chamber were implanted subcutaneously into SCID mice, which were then treated from day 0 to 5, On day 6, the anti-angiogenic effects were assessed. Results indicated that TSU-68 significantly inhibited the growth of subcutaneous tumors. In the hepatic metastasis model, liver weights of the TSU-68-treated group were significantly reduced, compared to those of control mice. In the DAS assay, the angiogenic indices of the treated groups were significantly decreased for HT-29, WiDr and WAV-I tumors, with T/C ratios of 13.4, 50 and 35.3%, respectively. As TSU-68 significantly inhibited tumor growth and liver metastasis formation of human colon cancer xenografts, probably through anti-angiogenic activity, this agent may be useful for the treatment of colon cancer.

Administration, Oral↗
PubMed2005

[Preoperative combination chemotherapy with TS-1 is effective in a case gastric cancer with peritoneal dissemination].

We report a case of peritoneal cancer dissemination with Type 4 gastric cancer, successfully treated with combination chemotherapy with TS-1. The patient was a 59-year-old female, who complained of abdominal distension with pain, weight loss, and poor appetite. She was diagnosed as unresectable Type 4 gastric cancer, T3N2MOHOP1CY1M0, Stage IV with massive ascites (cytology: Class V). After 2 courses of combined chemotherapy with TS-1 and cisplatin (CDDP), primary tumor reduction was confirmed and no cancer cells were detected from a pathological investigation with biopsied specimens by endoscopy. As additional therapy for remained ascites, intraperitoneal administration of paclitaxel and docetaxel was performed, resulting in a remarkable decrease of ascites with cytological disappearance of cancer cells. The patients underwent total gastrectomy with lymph node dissection, pathological diagnosis of primary site and lymph nodes showed grade 2 effect, and no cancer cells were detected in ascites and peritoneum, microscopically. While she died of peritoneal recurrence after the surgery, the case suggested the clinical advantage of controlling the advanced cancer-bearing state by combination chemotherapy with TS-1, instead of surgery.

Adenocarcinoma↗
PubMed2005

[A case of colorectal cancer effectively treated with UFT/LV].

5-FU/LV therapy has been standard chemotherapy for advanced and recurrent colorectal cancer. Several studies reported that a new alternative chemotherapy, UFT/LV, had anti-cancer effects the same as with conventional 5-FU/LV therapy. We report a patient who had advanced and recurrent colorectal cancer treated with UFT/ LV. This 70-year-old male was admitted to our hospital because of a right lower abdominal mass, which was diagnosed as a peritoneal recurrence of transverse colon cancer by abdominal CT. UFT/LV therapy was started on an outpatient basis. After one course of chemotherapy, the intra-abdominal mass disappeared, and this therapy was continued for three courses. He did not suffer from any adverse effect during chemotherapy. Although this therapy was resumed because of the recurrence at the same site after nine months, it was refractory to chemotherapy. Thereafter, surgical resection was performed, and it was diagnosed as lymph node metastasis of previous surgery.

Adenocarcinoma↗
PubMed2004

Antitumor effect induced by dendritic cell (DC)-based immunotherapy against peritoneal dissemination of the hamster pancreatic cancer.

Establishing a method to control peritoneal dissemination is one of the most pressing issues in the postsurgical treatment of pancreatic cancer. In the present study, we investigated the effect of dendritic cell (DC)-based immunotherapy on peritoneal disseminations of hamster pancreatic cancer cells, PGHAM-1. After the orthotopically inoculation of 2 x 10(6) PGHAM-1 cells, DC pulsed with PGHAM-1-derived tumor lysates, DC alone or PBS as a vehicle was injected intraperitoneally (i.p.) three times at weekly intervals. The group treated with DC or DC+lysate was found to have smaller disseminated tumors than the vehicle-treated. In addition, mean survival time in the DC+lysate groups was significantly longer than the PBS group. These findings suggested that DC-based immunotherapy might be efficient for the treatment of peritoneal disseminations of the pancreatic cancer.

Animals↗
PubMed2004

Surgical and endovascular procedures for treating isolated iliac artery aneurysms: ten-year experience.

Characteristics of atherosclerotic isolated iliac artery aneurysms (IAAs) and various strategies for their treatment were assessed retrospectively. The computerized medical records of 18 patients who underwent surgical or endovascular treatment of an IAA during the 10 years from April 1993 to March 2003 at our university hospital were reviewed to obtain information on patient demographics, risk factors, type of IAA treatment, and outcome. Additional data were obtained by mail and telephone. Patients with an IAA were compared with 168 patients treated for an abdominal aortic aneurysm (AAA) also at our institution. Early in the series of isolated IAA repairs, patients underwent prosthetic graft interposition ( n = 7) or thromboexclusion ( n = 4). Subsequently, patients had either endovascular thromboembolization ( n = 4) or endovascular thromboembolization with femorofemoral crossover bypass ( n = 3). No perioperative deaths occurred in the series. Deep venous thrombosis developed postoperatively in one patient; there were no other serious complications. The cumulative patency rate for the implanted interposition grafts during the mean observation time of 5.5 years was 100%. No endoleakage was observed after the endovascular procedures. In the long-term, five patients died of causes unrelated to the IAA treatment. A statistical analysis revealed no significant differences between the IAA group and the AAA group with respect to atherosclerotic risk factors. In conclusion, open surgical procedures to repair isolated IAAs generally have a good outcome, although the risk of injury to adjacent iliac veins remains. Endovascular treatments appear to have some advantages, but studies including long-term follow-up are needed to assess the efficacy and durability of prosthetic grafts used for these procedures.

Aged↗
PubMed2004

Comparison of K-ras point mutation distributions in intraductal papillary-mucinous tumors and ductal adenocarcinoma of the pancreas.

Intraductal papillary-mucinous tumors (IPMT) consist of cells with varying histologic degrees of severity and exhibit multiple tumor loci; however, whether or not these lesions exhibit the same genetic changes has not been clarified. To investigate this point, we analyzed K-ras mutations in multiple IPMT lesions from each patient enrolled in our study and compared our findings to those for patients with ductal adenocarcinoma of the pancreas (DC). Twenty IPMT specimens and 7 DC specimens were resected, microdissected and analyzed for the presence of K-ras mutations. The mutated genes were then sequenced using a genetic analyzer. K-ras mutations were observed in 80% of IPMT and 100% of DC patients. More than 2 types of K-ras mutation were observed in the main tumors of 43.8% of IPMT and 0% of DC patients. K-ras mutations in peritumoral and separated lesions were observed in 66.7% and 62.5% of IPMT patients, respectively. At least one identical mutation between the main tumor and the peritumoral or separated lesions was recognized in all of the IPMT patients with those lesions. Different mutations from those in the main tumor were observed in 40% of IPMT patients with separated lesions. The survival curve of IPMT-carcinoma patients with more than 2 types of K-ras mutation in the main tumor was better than that with one type of K-ras mutation. IPMT patients exhibit a remarkably genetic heterogeneity in main tumor and have good prognosis.

Adenocarcinoma↗
PubMed2004

Loss of p16INK4a expression is associated with vascular endothelial growth factor expression in squamous cell carcinoma of the esophagus.

Vascular endothelial growth factor (VEGF) expression has been suggested to correlate with intratumoral microvessel density, tumor advancement and prognosis in esophageal squamous cell carcinoma (ESCC). Previous studies have showed that disruption of cell cycle regulator p16 is related to oncogenesis and tumor progression in ESCC. We hypothesized that VEGF expression in ESCC is reflected by abnormalities in the p16(INK4a) gene. To clarify the regulatory role of p16(INK4a) in VEGF expression in vitro, we transferred the p16(INK4a) gene into a p16(INK4a)-deleted ESCC cell line and observed changes in VEGF expression. Furthermore, we immunohistochemically assessed the expression of the cell cycle regulators (p16, p53 and RB) and VEGF in 90 surgically resected specimens of ESCC. Introduction of p16(INK4a) cDNA by the p16 expression vector significantly suppressed cell proliferation in the p16(INK4a)-deleted cell line TE8 (p < 0.0001). VEGF secretion by TE8 cells transfected with the p16(INK4a) vector was significantly suppressed as compared to non-transfected TE8 cells (p < 0.0001) and TE8 cells transfected with a control vector (p = 0.0015). The immunohistochemical studies of ESCC primary tumor specimens showed that loss of p16 expression was significantly correlated with VEGF-positive expression (p = 0.0004). The cumulative postoperative survival rate in the group with p16-positive and VEGF-negative expression was significantly higher than in the other groups. Neither p53 nor RB expression had any impact on outcome. Aberrant p53 expression tended to be associated with VEGF expression, but the trend did not reach statistical significance. Our study demonstrated that VEGF expression was correlated with p16 expression in ESCC. Our results suggest that p16 may have a regulatory role in VEGF expression in ESCC.

Aged↗
PubMed2004

Programmed death-1-programmed death-L1 interaction is essential for induction of regulatory cells by intratracheal delivery of alloantigen.

BACKGROUND: Programmed death (PD)-1 has been implicated in peripheral tolerance. The authors investigated the roles of PD-1 and its ligands, PD-L1 and PD-L2, in the induction of regulatory cells by intratracheal delivery of alloantigen. METHODS: CBA (H-2k) mice were pretreated with intratracheal delivery of C57BL/10 (H-2b) splenocytes and administration of monoclonal antibody (mAb) specific for PD-1, PD-L1, or PD-L2. Seven days later, C57BL/10 hearts were transplanted into the pretreated CBA mice. Some naive CBA mice underwent adoptive transfer of splenocytes from the pretreated CBA mice and transplantation of C57BL/10 heart. RESULTS: Untreated CBA mice rejected C57BL/10 cardiac grafts acutely (median survival time [MST], 7 days). Pretreatment with intratracheal delivery of C57BL/10 splenocytes prolonged graft survival significantly (MST, 65 days). Administration of control immunoglobulin (Ig) G or anti-PD-L2 mAb did not significantly affect the prolongation (MST, 72 and 68 days, respectively). In contrast, anti-PD-1 or anti-PD-L1 mAb abrogated the prolongation (MST, 18 and 17 days, respectively). Adoptive transfer from mice pretreated with intratracheal delivery of alloantigen plus control IgG or anti-PD-L2 mAb prolonged survival of C57BL/10 grafts in secondary CBA recipients (MST, 72 and 56 days, respectively). However, concurrent administration of anti-PD-1 or anti-PD-L1 mAb abrogated prolonged survival after the adoptive transfer (MST, 14 and 20 days, respectively). CONCLUSIONS: PD-1-PD-L1 interaction was essential for induction of regulatory cells by intratracheal delivery of alloantigen.

Adoptive Transfer↗
PubMed2004

Universal applications of sentinel node technology.

The sentinel node (SN) concept was originally proposed by several pioneers in the middle of the last century. After Donald Morton and his colleagues demonstrated the clinical significance of the SN concept in melanoma, it attracted vast attention in surgical oncology. At recent international conferences, a number of new approaches in this field for various solid tumors have been reported. Now, there are several possible applications with different technological aspects, such as individualized surgical management of solid tumors, multidisciplinary treatments, and novel therapeutic approaches. This article provides an overview of the future potential of SN technology.

Humans↗
PubMed2004

Current status and future prospects of sentinel node navigational surgery for gastrointestinal cancers.

Until the late 1990s, the application of the sentinel node (SN) concept to gastrointestinal (GI) malignancies was not recognized because of the multidirectional and complicated lymphatic flow from the GI tract. However, several studies supporting the validity of the SN concept for GI cancers have been reported in the past 5 years. Because of its anatomical location, gastric cancer is one of the most suitable targets for minimally invasive surgery based on SN status. Laparoscopic local resection is theoretically feasible for curative treatment of SN-negative early gastric cancer. Although SNs in esophageal cancer are multiple and are distributed widely from the cervical to the abdominal area, selective and modified lymphadenectomy for clinically N0-stage esophageal cancer is likely to become feasible and clinically viable. Total mesorectal excision (TME) is accepted as a standard surgical procedure for rectal cancer. However, there is a risk of aberrant distribution of SNs beyond the extent of TME; for example, SNs may be lateral to the lower rectum. SN mapping with scintigraphy is useful for effective sampling of SNs in unexpected areas and accurate staging without extensive lymph node dissection. There are several practical issues to be overcome. The techniques and feasibility of laparoscopic SN sampling are still under investigation. Large-scale multicenter prospective validation studies for SN mapping in GI cancer are essential. If these remaining issues can be solved, SN mapping for GI cancer will have great clinical impact.

Biliary Tract Neoplasms↗
PubMed2004

Historical review of lymphatic mapping in gastrointestinal malignancies.

The advent of sentinel lymph node mapping (SLNM) has had a profound impact on the surgical management of breast cancer and melanoma over the past decade. However, SLNM in gastrointestinal malignancies is still in its infancy. The role of SLNM in gastrointestinal malignancies is to increase staging accuracy and to reduce the understaging associated with standard surgical and pathological techniques. Numerous authors have described the successful use of SLNM in colon, rectal, gastric, esophageal, and anal canal malignancies, with a high degree of accuracy and upstaging by detailed pathological analysis of the sentinel nodes. Over the past 2 years, research and publications related to gastrointestinal lymphatic mapping have dramatically increased worldwide.

Colorectal Neoplasms↗