Biomedical subjects

M Iida

Publications and source records attributed to M Iida.

743 records · Page 42Linked to original sources

PubMedDate not supplied

Relationship between ascorbyl radical intensity and apoptosis-inducing activity.

Ascorbic acid and its related compounds were compared for their ascorbyl radical intensity and apoptosis-inducing activity. Sodium L-ascorbate, L-ascorbic acid, D-isoascorbic acid, sodium 6-beta-O-galactosyl-L-ascorbate and sodium 5,6-benzylidene-L-ascorbate, at the concentration of 1-10 mM, induced apoptotic cell death characterized by cell shrinkage, nuclear fragmentation and internucleosomal DNA cleavage in human promyelocytic leukemic HL-60 cells. On the other hand, L-ascorbic acid-2-phosphate magnesium salt and L-ascorbic acid 2-sulfate did not induce any of these apoptosis-associated characteristics. ESR measurements revealed that all the active compounds were progressively degraded, producing the ascorbyl radical (g = 2.0064, hfc = 0.17 mT) in culture medium, whereas the inactive compounds were stable and did not produce the ascorbyl radical. Cytotoxicity began to appear when the radical intensity exceeded a certain threshold level. In the presence of N-acetyl-L-cysteine, both ascorbyl radical intensity and apoptosis-inducing activity were significantly reduced. These data suggest the possible involvement of the ascorbyl radical in apoptosis induction by ascorbic acid-related compounds. Exposure of HL-60 cells to ascorbic acid or its active derivatives resulted in the rapid elevation of intracellular Ca2+ concentration, which might serve as the initial signal leading to the cell death pathway.

Antineoplastic Agents↗

PubMedDate not supplied

Characteristic endoscopic features of intestinal lymphangiectasia: correlation with histological findings.

Six patients with histologically proven intestinal lymphangiectasia were evaluated for the endoscopic features. White villi and/or spots, previously reported as endoscopic findings, were seen. Furthermore, white nodules and submucosal elevations with or without white mucosa were observed. All patients demonstrated the appearance of submucosal elevations. The four characteristic endoscopic features were correlated with histological findings. It is considered that these endoscopic features are of value for the diagnosis of intestinal lymphangiectasia in patients with protein-losing enteropathy.

Adolescent↗

PubMedDate not supplied

Effect of methionine depletion on growth and apoptosis in various tumor cell lines.

Sodium ascorbate, sodium 5,6-benzylidene-L-ascorbate (SBA), gallic acid and caffeic acid induced apoptotic cell death in human myelogenous leukemic cell lines, and stimulated oxidation of methionine into methionine sulfoxide in the culture medium. When various tumor cell lines were cultured in methionine-free medium, their growth was nearly terminated at G1 phase of the cell cycle, producing much smaller number of apoptotic cells. Addition of methionine sulfoxide to the methionine-free medium did not stimulate the apoptosis induction. These data suggest that induction of apoptosis by ascorbates, gallate or by caffeate cannot be simply explained by methionine oxidation.

Antioxidants↗

PubMedDate not supplied

Fluoride release from a light-cured bonding material in openbite orthodontic patients.

This study was undertaken to clarify whether the salivary fluoride concentration on the anterior and premolar teeth, released from an orthodontic bonding material, differed between openbite and non-openbite patients. Using fluoride-releasing bonding materials, brackets were bonded to the teeth in openbite and in non-openbite patients. Saliva films on the tooth surfaces near the brackets were collected with filter paper and fluoride concentrations in the saliva were determined by using a fluoride electrode technique. Saliva was collected and analyzed at different periods after the bonding. Fluoride concentrations in the saliva increased sharply immediately after bonding, decreased gradually thereafter, then leveled off. Fluoride concentrations in the saliva on the tooth surfaces were higher in openbite patients for one day to as long as one week. The results of the two-way analysis (ANOVA) showed that the differences in the overbite factor (openbite, non-openbite) contributed to the variances the most (p < 0.001; contribution, 59.50 percent after one day and p < 0.01; contribution, 49.63 percent after 3 days). In conclusion, the fluoride released from the bonding materials on the tooth surfaces was retained more in openbite than in non-openbite patients, suggesting their lower flow rate of saliva.

Adhesives↗

PubMedDate not supplied

Expression of somatostatin messenger RNA and receptor in cultured brain tumor cells.

In order to understand the role of somatostatin in tumor cell growth, the expression of somatostatin in 7 cultured brain tumor cells was investigated. Radioimmunoassay demonstrated the production of somatostatin into the culture supernatant of 6 tumor cells. The expression of somatostatin mRNA and receptor was investigated by reverse transcription polymerase chain reaction (RT-PCR) and a binding assay with 125I-somatostatin-14, respectively. Only two cell lines, GBS-1 and U87MG, expressed somatostatin mRNA, whereas somatostatin receptor was expressed in all cultured cells. These results suggest that somatostatin is an important factor for regulating cell growth.

Brain Neoplasms↗