Biomedical subjects

M Yoshihara

Publications and source records attributed to M Yoshihara.

204 records · Page 12Linked to original sources

PubMedDate not supplied

c-myc gene mutation in gastric mucosa-associated lymphoid tissue (MALT) lymphoma and diffuse large B-cell lymphoma.

The c-myc gene is involved in important cellular processes, including cell proliferation, differentiation, and apoptosis. We analyzed mutation of the c-myc gene in 51 patients with gastric lymphoma [27 patients with low-grade mucosa-associated lymphoid tissue (MALT) lymphoma, 11 with high-grade MALT lymphoma, and 13 with diffuse large B-cell lymphoma (DLL)], by polymerase chain reaction-single strand conformation polymorphism (PCR-SSCP) analysis. We also evaluated the relationship between mutation of the c-myc gene and regression of low-grade MALT lymphoma after Helicobacter pylori (H. pylori) eradication. Mutation in exon 2 of the c-myc gene was present in 2 of 20 (10%) patients with low-grade MALT lymphoma, in 1 of 7 (14%) patients with high-grade MALT lymphoma, and none of 10 patients with DLL. The 3 patients who had mutations of the gene, showed different patterns of mobility shift, suggesting different mutations. In addition, 15 patients with low-grade MALT lymphoma received anti-H. pylori therapy. All the patients achieved eradication. Nine of the 15 (60%) patients with low-grade MALT lymphoma showed complete regression (CR), 3 (20%) showed partial regression (PR), and 3 (20%) showed no change (NC). One of the 9 (11%) CR patients had a mutation of the c-myc gene. None of the 3 PR and 3 NC patients had mutation of the gene. There was no significant difference between the frequencies among the c-myc gene mutation in CR, in PR and in NC patients. These data suggest that mutation of the c-myc gene may not be commonly associated with development of gastric MALT lymphoma and DLL, and may not be associated with regression of low-grade MALT lymphoma after H. pylori eradication.

Anti-Ulcer Agents↗

PubMedDate not supplied

Microsatellite instability at D18S61 is associated with no regression of gastric mucosa-associated lymphoid tissue lymphoma after Helicobacter pylori eradication.

Recent studies have shown 70-80% of gastric low-grade mucosa-associated lymphoid tissue (MALT) lymphomas regressing in response to eradication of Helicobacter pylori (H. pylori). Genetic mechanism of regression of gastric MALT lymphoma after H. pylori eradication remains unclear. To clarify the issue, we evaluated microsatellite instability (MSI) at 12 microsatellite loci in 15 patients with gastric low-grade MALT lymphoma, who received eradication therapy of H. pylori. H. pylori infection was observed in all the patients. After eradication therapy of H. pylori, patients were observed for a median of 21 months (range, 6-49 months). Eradication was achieved in all the patients. Nine of the 15 (60%) patients showed complete regression (CR), 3 (20%) partial regression (PR), and 3 (20%) no change (NC). MSI was detected in 3 of the 15 (20%) patients with low-grade MALT lymphoma. Compared with response to eradication therapy of H. pylori, MSI was detected in 1 of the 12 (8%) CR and PR patients, and in 2 of the 3 (67%) NC patients. Especially, MSI at D18S61 was detected in 2 of the 3 (67%) NC patients but in none of the 12 CR and PR patients. There was a significant difference between frequency of MSI at D18S61 in NC patients and that in CR and PR patients (p<0.05). These data suggest that MSI at D18S61 may be associated with lack of regression of gastric MALT lymphoma after H. pylori eradication.

Anti-Ulcer Agents↗

PubMedDate not supplied

Reduction in the incidence of Helicobacter pylori-associated carcinoma in Japanese young adults.

Helicobacter pylori (Hp) is a major risk factor for gastric carcinogenesis. In Japan, the incidence of Hp infection in young adults has declined markedly. The purpose of this study was to clarify this trend in the incidence of Hp-associated gastric carcinoma (GCa) in young (under 30 years of age) Japanese patients. We enrolled 53 such patients who underwent surgical resection of GCa in one of 18 hospitals in the Hiroshima prefecture between 1976 and 1999. The patients were classified into groups based on three 8-year periods (1976-83, 1984-91, and 1992-1999) in which their cases occurred. We compared the numbers of patients and estimated the histology of carcinomas, grades of gastritis and Hp infection histologically. Of the 53 patients, 49 (92%) showed Hp infection. The frequency of GCa in young adults has decreased gradually (21, 18, and 14 patients in 1976-83, 1984-91 and 1992-99, respectively). The numbers of Hp-positive carcinomas decreased radically (21, 17 and 11 patients, respectively). This trend was associated with improvement in the degree of gastritis in non-neoplastic mucosa. Of the four Hp-negative patients, three had signet ring cell carcinoma. Moreover, the numbers of patients with non-signet ring cell carcinoma also decreased (18, 12 and 7 patients in each period, respectively). These results suggest that Hp-associated carcinoma has declined gradually in young Japanese.

Adolescent↗

PubMedDate not supplied

pS2 expression as a possible diagnostic marker of colorectal carcinoma in ulcerative colitis.

This study was performed to evaluate the significance of pS2 and MUC1 expressions in ulcerative colitis (UC)-associated colorectal neoplasias. Tissues were collected from 6 patients with UC-associated colorectal neoplasias treated surgically. Specimens were 13 adenocarcinomas, 40 dysplasias (20 high-grade dysplasias, 20 low-grade dysplasias), and 60 normal mucosae. Tissues were also collected from patients without UC treated surgically or endoscopically. pS2, p53, and MUC1 expressions were examined immunohistochemically and compared. The K-ras codon 12 mutation was investigated by single-strand conformation polymorphism analysis. In patients with UC, the incidence of pS2 expression was significantly higher (p<0.01) in adenocarcinomas than it was in dysplasias, and no pS2 expression was seen in normal mucosae. p53 overexpression was detected in 50% (10/20) even in low-grade dysplasias. MUC1 expression was seen only in invasive carcinomas, but it was seen in 100% of cases (3/3). K-ras gene mutations were detected in 2 (20%) of 10 carcinomas. In low and high-grade dysplasias, the incidences of pS2 expression were significantly (p<0.01) lower than the incidences of p53 overexpression, however, in UC-associated carcinomas there was no significant difference; pS2 expression and p53 overexpression were detected in 13 of 13 (100%) cases and in 12 of 13 (92%) cases, respectively. These results suggest that p53 overexpression may be a diagnostic marker of neoplasia, and that pS2 expression may be a diagnostic marker of colorectal carcinoma in case of UC.

Adult↗

PubMedDate not supplied

Effect of pine seed shell extract on microbial and viral infection.

Pretreatment of mice with ammonia extract of seed shell of Pinus Koraicenis, via the intraperitoneal or intravenous route, effectively protected them from lethal infection of Escherichia coli, Klebsiella pneumoniae and Staphylococcus aureus. The pine seed shell extract also moderately inhibited syncytium formation and cytopathogenic effect induced by human immunodeficiency virus (HIV) infection in cultured human lymphotropic virus type I (HTLV-1) positive MT-4 cells. These data suggest a medicinal potential of pine seed shell extract against opportunistic infection in HIV patients.

Animals↗

PubMedDate not supplied

Radical modulation activity of lignins from a mangrove plant, Ceriops decandra (Griff.) Ding Hou.

The radical modulation activity of hot water and alkaline extracts from leaf of Ceriops decandra, a mangrove plant, was investigated using ESR spectroscopy. IR and NMR analyses demonstrate that the leaf extracts have a lignin-like polyphenolic structure. All these extracts produced radical(s) under alkaline conditions. The radical intensity of sodium ascorbate was slightly reduced at lower concentrations of the extracts, but it was synergistically enhanced at higher concentrations. All the extracts effectively scavenged superoxide anion, produced by hypoxanthine-xanthine oxidase reaction. Pretreatment of mice with the extracts significantly protected them from the lethal infection by E. coli. Similar activity was found in lignins from pine seed shell of Pinus parviflora Sieb. et Zucc. These data further support the medicinal efficacy of plant extracts.

Animals↗