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Yusuke Saitoh

Publications and source records attributed to Yusuke Saitoh.

9 recordsLinked to original sources
PubMed2005

Spontaneous remission of primary diffuse large B-cell gastric lymphoma.

Spontaneous and complete disappearance of diffuse large B-cell lymphoma (DLBL) of the stomach is extremely rare. Although regression of gastric DLBL after eradication of Helicobacter pylori has recently been reported, we present two consecutive cases of stage I DLBL of the stomach which disappeared after only nonspecific therapy, including histamine 2-receptor antagonist (H2RA); both cases were documented histologically and endoscopically. Both patients were positive for H. pylori, and later received H. pylori eradication therapy. The disease has not recurred after 11 and 6 months, respectively. Our cases suggest that the option of combination therapy with H2RA either with or followed by H. pylori eradication is appropriate for consideration as an initial approach in standard therapy for stage I diffuse large B-cell gastric lymphoma.

Biopsy↗
PubMed2004

Reduction of syndecan-1 expression in differentiated type early gastric cancer and background mucosa with gastric cellular phenotype.

BACKGROUND: Syndecan-1 is known to play a role as a cell adhesion molecule, similar to E-cadherin, and is associated with the maintenance of epithelial morphology. The purpose of this study was to elucidate the role and alterations of syndecan-1 expression in comparison with those of E-cadherin in different cellular phenotypes of differentiated-type gastric cancers (DGCs). METHODS: A total of 80 DGCs at an early stage, and their adjacent mucosa, were evaluated by both immunohistochemistry and in situ hybridization. Syndecan-1 and E-cadherin were assessed by immunohistochemical staining with an anti-syndecan-1 and an anti-E-cadherin antibody, respectively. Based on immunohistochemistry, DGCs and their surrounding mucosa were divided into four types: gastric type (G-type), ordinary type (O-type), complete-intestinal type (CI-type), and null type. RESULTS: The expression sites of syndecan-1 mRNA mostly coincided with those of syndecan-1 protein. Syndecan-1 expression was significantly lower in G-type cancers (30%) than in O- (81%) and CI-type cancers (92%) ( P = 0.0001 and P = 0.004, respectively), but E-cadherin did not show this result. In addition, syndecan-1 expression was significantly reduced in DGCs comprised partly of poorly differentiated adenocarcinoma or signet-ring cell carcinoma, compared to DGCs demonstrating papillary and/or tubular adenocarcinoma ( P = 0.02). G-type intestinal metaplasia (IM) surrounding the tumors was observed in 21% of G-type cancers, in 0% of O-, and in 10% of CI-type cancers ( P = 0.01; G-type vs O-type). Reduction of syndecan-1 expression was significant in G-type IM (25%) compared to non-G-type IM (75%; P = 0.02). CONCLUSIONS: Syndecan-1 plays a role in the growth of G-type cancers at an early stage compared with E-cadherin changes, and the reduction of syndecan-1 expression in IM surrounding the tumors may influence the growth of G-type cancer.

Adenocarcinoma↗
PubMed2003

Cell kinetics and genetic instabilities in differentiated type early gastric cancers with different mucin phenotype.

To clarify the biological impact and molecular pathogenesis of cellular phenotype in differentiated-type gastric cancers (DGCs), we investigated cell kinetics and genetic instabilities in early stage of DGCs. A total of 43 early gastric cancers (EGCs) were studied. EGCs were divided into 3 phenotypic categories: gastric (G type, n = 11), ordinary (O type, n = 20), and complete intestinal (CI type, n = 12) based on the combination of HGM, ConA, MUC2, and CD10. Proliferative index (PI), apoptotic index (AI), and p53 overexpression were investigated by immunohistochemical staining with anti-Ki-67, the terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling method, and p53 antibody, respectively. Using a high-resolution fluorescent microsatellite analysis system, microsatellite instability (MSI) and loss of heterozygosity (LOH) were examined. Frameshift mutation analysis of transforming growth factor-beta type II receptor (TGF-betaRII) and bcl-2-associated X (BAX) in cancers with MSI was also performed. The mean AI/PI ratio values were 0.04 for G-type, 0.10 for O-type, and 0.13 for CI-type cancers--significantly lower in G type than in O and CI types (P = 0.02 and P = 0.001, respectively). No difference in the incidence of MSI and LOH was seen among the 3 cellular phenotypes. However, the major pattern of MSI, which showed drastic and widely dispersed changes and is related to an increased risk for cancer, was significantly higher in G and O types than in CI type (P <0.005). No frame shift mutations of TGF-betaRII or BAX were found in CI-type cancers. These results indicate that G-type cancers are likely to show more aggressive behaviors than CI-type cancers, and that O-type cancers show the intermediate characteristics of both types. However, the molecular pathogenesis of each phenotypic cancer is not associated with microsatellite alterations.

Adenocarcinoma↗
PubMed2002

Quantitative analysis for human glucocorticoid receptor alpha/beta mRNA in IBD.

We have previously reported that in peripheral blood mononuclear cells (PBMC), the augmented expression of the beta isoform of the human glucocorticoid receptor (hGRbeta), as a putative dominant negative regulator of glucocorticoid action, is associated with glucocorticoid (GC) unresponsiveness of UC patients. In this study, we quantified the levels and serial changes of hGR transcripts in PBMC of IBD patients by a real-time fluorescence monitoring of PCR. As results, relative hGRbeta mRNA expression was significantly higher in the active stage of UC than in inactive periods of UC or CD patients. Longitudinal analysis revealed that hGRbeta mRNA expression in UC was increased after the relapse of inflammation, suggesting that the overproduction of cytokines during inflammation may be responsible. In in vitro culture experiments of human lymphoid cell (CEM) and human PBMC, IL-7, and IL-18 increased hGRbeta mRNA expression in these cells but GC itself did not. Through these analyses, it is indicated that the inflammatory cytokines altered the splicing condition of the primary transcript of hGR gene in IBD patients.

Adult↗
PubMed2002

High-frequency probe EUS-assisted endoscopic mucosal resection: a therapeutic strategy for submucosal tumors of the GI tract.

BACKGROUND: The aim of this study was to evaluate the efficacy and safety of high-frequency probe EUS (HFPE)-assisted endoscopic mucosal resection in the management of submucosal tumors of the GI tract. METHODS: HFPE-assisted endoscopic mucosal resection was attempted in 28 patients with submucosal tumors less than 2 cm in diameter. HFPE was performed with a 20-MHz "through-the-scope" probe. Saline solution was injected into the submucosa. After confirming detachment of the lesion from the muscularis propria by repeat HFPE, endoscopic mucosal resection was performed with a lift-and-cut or endoscopic mucosal resection cap technique. Follow-up endoscopy was performed in all patients. RESULTS: Submucosal tumors from the following areas were included: esophagus 3, stomach 4, duodenum 3, and colon 18. The submucosal tumors were located in the upper third (n = 3), middle third (n = 18), and lower third (n = 7) of the submucosa. Twenty-one submucosal tumors were removed by the lift-and-cut technique and 6 by the cap method. One patient required surgical resection after unsuccessful endoscopic mucosal resection. The origin and depth of penetration of all lesions was accurately depicted by HFPE. Median tumor diameter was 9 mm (range 3-20 mm). Resection was successful and complete in 93% of the cases. There were no immediate postprocedure complications (exact 95% CI [0%, 12.3%]). During a median follow-up of 21.5 months (range 2-74 months) no recurrence was found. CONCLUSIONS: HFPE-assisted endoscopic mucosal resection is safe and effective for the management of selected submucosal tumors of the GI tract. A management algorithm based on endoscopic and HFPE findings is proposed.

Adult↗
PubMed2002

Minute findings by magnifying colonoscopy are useful for the evaluation of ulcerative colitis.

BACKGROUND: Colonoscopy has an important role in the diagnosis of ulcerative colitis. However, colonoscopic findings are inadequate for the prediction of relapse without histologic examination. In this study, the role of magnifying colonoscopy in ulcerative colitis was evaluated. METHODS: One hundred sixteen magnifying colonoscopy observations were made in 61 patients with ulcerative colitis between January 1994 and October 1998. A simple classification of magnifying colonoscopic findings into 5 categories was devised as follows: regularly arranged crypt openings, villous-like, minute defects of epithelium, small yellowish spots, and coral reef-like appearance. The colonoscopic findings by classification were compared with histopathologic findings, and the usefulness of the classification for predicting relapse was prospectively analyzed in 18 patients. RESULTS: Compared with grade as determined by conventional colonoscopy, there was a better correlation between the classification of findings by magnifying colonoscopy and histopathologic findings (r(2) = 0.665, 0.807, respectively). Of 18 patients studied prospectively, 7 of 9 with minute defects of epithelium relapsed within 6 months, and the cumulative nonrelapsing rate was significantly lower in patients with minute defects of epithelium compared with those without minute defects of epithelium (p = 0.0059). Moreover, minute defects of epithelium was found to be a significant independent predictive factor for relapse (multivariate analysis, Cox proportional hazards model; p = 0.0203). CONCLUSIONS: Our proposed classification of magnifying colonoscopic findings in patients with ulcerative colitis is useful for the evaluation of disease activity and for the prediction of periods of remission.

Adolescent↗
PubMed2002

Natural history of colorectal nonpolypoid adenomas: a prospective colonoscopic study and relation with cell kinetics and K-ras mutations.

OBJECTIVE: Serial colonoscopic observations were prospectively conducted to elucidate the natural history of nonpolypoid tumors. Furthermore, to clarify whether cell kinetic status affects the tumor development, proliferative indices, apoptotic indices, and K-ras codon 12 point mutations on biopsy specimens were investigated. METHODS: Seventy-five colorectal tumors, 13 polypoid and 62 nonpolypoid type (56 flat elevated and six depressed type) were studied. Proliferating and apoptotic cells were detected with anti-Ki-67 antibody and the terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling method, respectively. Point mutations at K-ras codon 12 were examined by enriched polymerase chain reaction-based restriction fragment length polymorphism assay. RESULTS: The average follow-up period was 22 months (range 1-50). The lesions of subsequent exophytic growth, unchanged shape, depressed growth, and disappearance were observed in 0%, 92%, 0%, and 8% of polypoid type, in 39%, 39%, 13%, and 9% of flat elevated type, and in 33%, 67%, 0%, and 0% of depressed type, respectively. There was no significant difference in tumor size between initial and follow-up colonoscopy. Nonpolypoid tumors apparently changed to the exophytic growth during 2 yr or more. The tumors with exophytic growth had significantly higher proliferative indices/apoptotic indices ratios than those with unchanged morphology and disappearance/depressed growth (p < 0.05, respectively). K-ras codon 12 point mutations did not correlate with tumor development. CONCLUSIONS: Cell kinetic status plays an important role in determining minute colorectal tumor development, but not K-ras codon 12 mutations. Minute nonpolypoid adenomas frequently tend to grow slowly, and nearly 40% of those become the exophytic growth with time. Most of minute nonpolypoid tumors seem to follow the adenoma-carcinoma sequence.

Adenoma↗
PubMed2002

[Two cases of stage IV type 4 gastric cancer with good response to TS-1].

We report two patients with Type 4 gastric cancers having multiple lymph node metastasis and carcinomatosa which responded well to TS-1. After administration of TS-1 orally for two courses, both patients showed improved extension of the gastric wall and almost complete reduction of metastatic lymph nodes. In case 2, colonic stenosis due to peritonum carcinomatosa disappeared after chemotherapy with TS-1. Total gastrectomy was performed in both patients in accordance with their wishes. It was confirmed histopathologically that TS-1 was effective against the primary sites and lymph node metastasis. Both patients are well without recurrence and continue taking TS-1.

Antimetabolites, Antineoplastic↗