Biomedical subjects

Michiko Miyazaki

Publications and source records attributed to Michiko Miyazaki.

5 recordsLinked to original sources

PubMed2005

Squamous cell carcinoma-related antigen in children with acute asthma.

BACKGROUND: Increased serum levels of squamous cell carcinoma-related antigen (SCCA) have been observed in patients with allergic disorders, such as atopic dermatitis and bronchial asthma. T(H)2 cytokines, which are known to be involved in the pathogenesis of allergic disorders, stimulate new synthesis of SCCA in cultured human airway epithelial cells. OBJECTIVE: To investigate whether SCCA levels increase during acute exacerbations of asthma in children and whether the T(H)2 cytokines, interleukin 4 (IL-4) and IL-13, are associated with SCCA levels. METHODS: Serum levels of SCCA, IL-4, and IL-13 were measured by enzyme immunoassay during the acute phase of an asthma exacerbation (on hospital admission) and in the recovery phase (after symptoms had subsided). RESULTS: In the 35 children who participated in this study, serum levels of SCCA were significantly elevated in the acute phase (mean +/- SD, 3.09 +/- 2.03 ng/mL) compared with the recovery phase (mean +/- SD, 1.47 +/- 0.64 ng/mL) of an asthma exacerbation (P < .001). In 12 children, the IL-13 levels were observed to correlate with SCCA levels during the recovery phase (r = 0.68, P = .02) but not during the acute phase of an asthma exacerbation. CONCLUSIONS: Serum SCCA levels increase during the acute phase of an asthma exacerbation. During this phase, the increased synthesis of SCCA is not associated with IL-13 but rather mediated by other undefined stimuli. IL-13 may contribute to the basal production of SCCA in asthmatic children.

Acute Disease↗

PubMed2004

Upregulation of interleukin-4 receptor by interferon-gamma: enhanced interleukin-4-induced eotaxin-3 production in airway epithelium.

Airway epithelial cells produce a number of chemokines, including eotaxins. Among the three known eotaxins, T helper (Th) type 2 cytokines have been observed to induce the expression of eotaxin-3 mRNA. This study investigated the effect of interferon (IFN)-gamma, a Th1 cytokine, on Th2 cytokine-induced eotaxin-3 production in a bronchial epithelial cell line, BEAS-2B. BEAS-2B cells produced eotaxin-3 after stimulation with the Th2 cytokines interleukin (IL)-13 and IL-4. When BEAS-2B cells were cultured with varying concentrations of IFN-gamma for 24 h, dose-dependent inhibition of Th2 cytokine-induced eotaxin-3 mRNA expression and protein production was observed. This was associated with downregulation of signal transducer and activator of transcription 6 activation. On the other hand, 2-d pretreatment of BEAS-2B cells with IFN-gamma dose-dependently enhanced Th2 cytokine-induced eotaxin-3 mRNA expression and production. IFN-gamma also increased the mRNA expression and protein production of IL-4 receptor (R) alpha in a time- and dose-dependent manner. In addition, IL-2Rgamma, a component of the type 1 IL-4R, was also upregulated by IFN-gamma. These results indicate that IFN-gamma has opposite effects on Th2 cytokine-induced eotaxin-3 production in BEAS-2B cells, depending on the length of exposure. Because high levels of IFN-gamma are produced during viral infection, airway viral infection may affect allergic airway inflammation in vivo by modulation of eotaxin-3 production.

Antineoplastic Agents↗

PubMed2003

Macrolide antibiotics inhibit prostaglandin E2 synthesis and mRNA expression of prostaglandin synthetic enzymes in human leukocytes.

We investigated the action of macrolide antibiotics, which are considered to have anti-inflammatory activity, on lipopolysaccharide (LPS)-stimulated prostaglandin (PG) E2 synthesis and the expression of mRNAs for cytosolic phospholipase A2 (cPLA2), cyclooxygenase (COX)-1, and COX-2 in human leukocytes. The production of LPS-stimulated PGE2 was significantly increased in peripheral polymorphonuclear leukocytes (PMNLs) and in mononuclear leukocytes (MNLs). Amounts of mRNAs for COX-2 and cPLA2, but not for COX-1, were enhanced by LPS in PMNLs and MNLs. The LPS-enhanced PGE2 synthesis and the expression of cPLA2 and COX-2 mRNAs were inhibited by clarithromycin, azithromycin and dexamethasone in PMNLs and MNLs. The mRNA expression of COX-1 in PMNLs was decreased by clarithromycin and azithromycin. Macrolide antibiotics inhibited PGE2 synthesis in human leukocytes by suppressing cPLA2, COX-1, and COX-2 mRNA expression. These data indicate one mechanism of macrolide anti-inflammatory activity.

Anti-Bacterial Agents↗

PubMed2003

The synthesis of isoquinoline alkaloid and its related compounds using alanine derivatives as chiral auxiliaries.

Chiral 1-substituted isoquinoline derivatives, which were obtained by the reaction using alanine derivatives as chiral auxiliaries, were transformed to (S)-2,3,9,10,11-pentamethoxyhomoprotoberberine (7) and a synthetic intermediate for O-methylkreysigine (9) in good yields and high stereoselectivity. The corresponding chiral allyl derivative of isoquinoline was transformed to a pyrrolidinoisoquinoline (16) in a highly enantioselective manner.

Alanine↗

PubMed2003

[Constraint-based approach to individual differences in insight problem-solving].

In this study, we explored individual differences in insight problem-solving. According to the dynamic constraint relaxation theory (Hiraki & Suzuki, 1998), there are three sources of individual differences in insight problem-solving: the initial strengths of constraints, the evaluation of problem-solving attempts, and the learning rate that updates the strength value of each constraint. In order to validate the theory's predictions, we compared the subjects who could solve a geometric insight problem within 10 minutes with those who could not. A microscopic analysis of the solution processes and rating task revealed that the initial strengths of the constraints and the adequacy of evaluation are different between the two, but their learning rates are not. These results suggest that insightful problem-solvers try non-standard attempts more often even in the initial phase of their problem-solving and evaluate their attempts more precisely. The results were discussed in contrast with other approaches to insight.

Humans↗