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Biomedical subjects

M Isobe

Publications and source records attributed to M Isobe.

387 records · Page 22Linked to original sources

Enhanced embryonic nonmuscle myosin heavy chain isoform and matrix metalloproteinase expression in aortic abdominal aneurysm with rapid progression.

Abdominal aortic aneurysms (AAAs) are characterized by structural deterioration of aortic wall leading to progressive dilatation. The histopathological changes in AAAs are particularly evident within the elastic media, which is normally comprised mainly of vascular smooth muscle cells (SMCs). There are vascular myosin heavy chain (MHC) isoforms; SM2 is specifically expressed in differentiated SMCs and SMemb is a nonmuscle-type MHC abundantly expressed in SMCs of the fetal aorta with an immature phenotype. Although AAA altered expression of matrix metalloproteinases (MMPs) and their tissue inhibitors (TIMPs), pathophysiological role of SMC phenotypic modulation in the AAA progression remains uncertain. To determine whether phenotypic modulation in vascular SMCs contributes to arterial medial degeneration, we examined MHC expression in SMCs of AAA. Aortic specimens were obtained from patients with slowly progressed AAA (n = 12) and rapidly progressed AAA (n = 5), and compared with normal aortic tissue (n = 3). Immunohistochemical staining was performed for detection of SMemb, SM2, MMP (types 2 and 9) and TIMP (types 1 and 2). Faint SMemb and abundant SM2 were observed in normal aorta, while the balance shifted to SMemb predominance in AAAs. Compared with slowly progressed AAA tissue, rapidly expanded AAA tissue demonstrated marked increases in SMemb expression with suppressed SM2. Predominant SMemb expression indicates presence of phenotypic modulated SMCs and enhanced MMP; while abundant TIMP was seen in mature SMCs expressing SM2. SMemb expression is markedly increased in AAA with MMP enhancement, and a significant imbalance between SMemb and SM2 results in rapid progression of AAA.

Aged↗

In situ interleukin-6 transcription in embryonic nonmuscle myosin heavy chain expressing immature mesenchyme cells of cardiac myxoma.

Cardiac myxomas are benign tumors which sometimes secrete interleukin-6 (IL-6), however, the pathogenesis and the IL-6 secreting cells are not clear. There are vascular myosin heavy chain isoforms; SM2 expression is specific to mature smooth muscle cells, while SMemb is a nonmuscle-type isoform which is expressed in immature mesenchyme cells. We hypothesized that immature mesenchyme cells play pivotal roles in the secretion of IL-6; we studied these expression in resected samples of myxoma. SMemb expression was increased but SM2 expression was not in the channels of myxoma. Increased IL-6 transcription was observed in the SMemb expressing cells in the channel. Therefore, mesenchyme cells with immature phenotype in the channel play pivotal roles of inflammation and pathogenesis of cardiac myxoma.

Adult↗

Localization of gene for human p53 tumour antigen to band 17p13.

Recently the gene for the cellular tumour antigen p53, a phosphoprotein found in increased concentration in a variety of human cells, had been mapped to region 17q22 by in situ hybridization techniques and has been shown to translocate to the chromosome carrying the translocation [t(15; 17)] associated with acute promyelocytic leukaemia (APL). Based on this finding it has been postulated that this gene has a role in the pathogenesis of APL. Here we present evidence that the gene for p53 is not located on the long arm of chromosome 17, but maps to band 17p13. We therefore suggest that this gene is not directly involved in the chromosome translocation observed in APL.

Antigens, Neoplasm↗

Two pathways in the biosynthesis of cadystins (gamma EC)nG in the cell-free system of the fission yeast.

Small metal-binding peptides, cadystins, with the general structure of (gamma-Glu-Cys)n-Gly ((gamma EC)nG), were synthesized in a cell-free system of fission yeast to examine the in vivo synthetic pathway. The crude enzyme for cadystin synthesis was prepared by ammonium sulfate precipitation (75% saturation) from the 120,000 x g supernatant of the cell extract, and the excess salt in the enzyme fraction was removed by Sephadex gel filtration. Using this crude enzyme fraction, it was shown that there were two pathways for cadystin biosynthesis. One pathway is gamma-Glu-Cys (gamma EC) dipeptidyl transfer from both glutathione (gamma ECG) and cadystins to glutathione and cadystins. The other one is gamma EC polymerization from (gamma EC)n and glutathione to (gamma EC)n + i, followed by glycine addition with glutathione synthetase.

Amino Acid Sequence↗

Molecular size of the diapause hormone of the silkworm Bombyx mori.

The diapause hormone (DH) responsible for arrested development of the silkworm Bombix mori consists of two active principles of peptide (A and B). Since both hormones form aggregates in aqueous phases, the molecular weights were determined by gel permeation chromatography of Merckogel OR 6000 using methanol-dichloromethane mixture as the developing agent. Gramicidins and modified peptides soluble in the organic solvents were used as the standard markers for the molecular weight measurements of the hormones. The molecular weights of DH-A and -B are estimated to be 3300 +/- 400 and 2000 +/- 200, respectively.

Animals↗

Eosinophil active cytokines and surface analysis of eosinophils in Churg-Strauss syndrome.

There are few reports regarding the measurement of cytokines and surface analysis of eosinophils in Churg-Strauss syndrome (CSS). To examine the pathophysiology of CSS, concentrations of cytokines in serum and bronchoalveolar lavage fluid (BALF), and surface antigens on peripheral blood eosinophils were analyzed in five patients with CSS. Concentrations of cytokines (interleukin-1 beta (IL-1 beta), tumor necrosis factor-alpha (TNF-alpha), interleukin-3 (IL-3), interleukin-5 (IL-5) and granulocyte/macrophage colony stimulating factor (GM-CSF) were measured using ELISA. Surface antigens on eosinophils in peripheral blood were analyzed using flow cytometry. A concentration of interleukin-5 (IL-5) and TNF-alpha in serum was detected in five cases; however IL-1 beta, GM-CSF, and IL-3 were detected in 3 of 5, 2 of 5, and 1 of 5 patients, respectively. In BALF, TNF-alpha and IL-5 were detected in 2 of 3 and 1 of 3 patients, respectively; however, neither IL-1 beta, GM-CSF, nor IL-3 was detected in any. Newly expressed surface antigens such as CD25, CD4, and CD69 were observed on peripheral blood eosinophils in five cases. CD54 and HLA-DR were expressed in 4 of 5 and 3 of 5 patients, respectively. Eosinophils in peripheral blood are activated to various degrees, possibly depending on cytokine stimulation. This eosinophil activation may be related to the clinical stage of CSS.

Adult↗

Mycotoxin analysis by fast atom bombardment tandem mass spectrometry.

Positive fast atom bombardment tandem mass spectrometry is demonstrated to be an effective technique for determination of crude aflatoxins and sterigmatocystin-related compounds. The molecular ion was selected by the first system and bombarded to produce characteristic daughter ions that could be used to identify mycotoxins in mixtures and with the same molecular weight.

Aflatoxins↗