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Biomedical subjects

H Iwase

Publications and source records attributed to H Iwase.

At least 145 records · Page 8Linked to original sources
PubMed1997

Evidence for involvement of IgA1 hinge glycopeptide in the IgA1-IgA1 interaction in IgA nephropathy.

The study was performed to investigate the role of the IgA1 hinge region in the IgA1-IgA1 interaction, which was observed previously in IgA nephropathy. The competitive inhibition assays of the IgA1-IgA1 binding were performed using the following candidates for inhibitors: native IgA1 hinge glycopeptide (nHGP), IgA1, IgA2, and IgG. The IgA1-IgA1 binding was definitely inhibited by the nHGP and the IgA1 (maximum of percent inhibition: 66.1 and 60.5%, respectively). There was no obvious inhibition in the IgA2 and the IgG. The inhibition curves of the nHGP and the IgA1 were significantly different from that of the IgG (P < 0.01, respectively). Furthermore, to reveal the detailed binding sites in the interaction, the same inhibition assays were performed using the following substances composing the IgA1 hinge glycopeptide: galactose (Gal), N-acetyl-galactosamine (GalNAc), Gal beta 1-3GalNAc, sialic acid, tetrapeptide PTPS, and synthesized hinge proline-rich peptide PVPSTPPTPSPSTPPTPSPS (sHP). sHP, Gal beta 1-3GalNAc, Gal, and GalNAc inhibited the binding (69.3, 34.1, 14.9, 14.6%, respectively). No obvious inhibition was observed in sialic acid and tetrapeptide PTPS. The inhibition curve of sHP was significantly different from that of the PTPS (P < 0.05). Those of Gal beta 1-3GalNAc, Gal, and GalNAc were also significantly different from that of sialic acid (P < 0.05, respectively). These results suggested that the IgA1-IgA1 interaction could be mediated by the core structure including the peptide and the sugars, except for sialic acid in the hinge region, resulting in the formation of the circulating macromolecular IgA1 in IgA nephropathy.

Adult↗
PubMed1997

Glass transition temperatures of dental porcelains determined by DSC measurement.

The differential scanning calorimetry (DSC) curves for three commercial dentin and incisal porcelains fused-to metal were measured using high-temperature DSC. The glass transition temperatures (Tg) were determined from the DSC curves at heating rates of 7-20 degrees C/min, and the activation energy was derived from an Arrhenius plot of negative reciprocal Tg vs. logarithm of heating rate. The Tg of the dental porcelains depended on the content of aluminum oxide, whereas the activation energy depended on the content of sodium oxide. The ultra-low fusing type porcelains had a low activation energy due to the higher content of sodium oxide than the other porcelains.

Aluminum Oxide↗
PubMed1997

Simultaneous quantitative analyses of c-erbB-2 protein, epidermal growth factor receptor, cathepsin D, and hormone receptors in breast cancer.

The overexpression of c-erbB-2 protein (ErbB2), epidermal growth factor receptor (EGFR), and/or cathepsin D (CD) in breast cancer is known to be a poor prognostic factor. Eighty frozen breast cancer specimens obtained at the initial operation were examined for ErbB2, EGFR, and CD by immunohistochemical assay (ICA) and enzyme immunoassay (EIA). Estrogen and progesterone receptors (ER and PgR) were measured simultaneously by EIA. The mean values +/- 1SD for ErbB2, EGFR and CD were 141 +/- 400 U/mg membrane protein (range: 0-3385), 4.88 +/- 4.33 fmol/mg membrane protein (range: 0-21.1), and 47.1 +/- 32.8 pmol/mg cytosol protein (range: 4.7-182), respectively. The percentage of specimens positive for ErbB2, EGFR, and CD was 12.5, 38.8, and 35%, when the tentative cutoff value were used as 200 U/mg protein, 5 fmol/mg protein, and 50 pmol/mg protein, respectively. These E1A results were correlated with ICA, EGFR and ER were negatively correlated. Although the prognostic value of ErbB2 and EGFR was superior to hormone receptors, ErbB2 and EGFR were interior as predictors compared with lymph node involvement and tumor size. Quantitation of ErbB2, EGFR, and CD can be performed readily using the same specimen in which hormone receptors are measured.

Adult↗
PubMed1997

Sequencing mitochondrial DNA from a tooth and application to forensic odontology.

Genetic identification can be complicated by long intervals between the time of death and examination of tissues, and sometimes only bone and teeth may be available for analysis. Several investigators have described the isolation of nuclear DNA from these materials, but all have indicated that the DNA is significantly degraded. Recently, the polymerase chain reaction (PCR) and direct DNA sequencing have enabled rapid and reliable characterization of specific highly polymorphic DNA sequences from different individuals. Above all, mitochondrial DNA sequences offer several unique advantages for the identification of human remains. The isolation of mtDNA from a tooth and the symmetrical PCR amplification and direct DNA sequencing of its most polymorphic regions are reported.

Alleles↗
PubMed1996

Low Frequency Loss of Heterozygosity in the BRCA1 Region in Japanese Sporadic Breast Cancer.

To investigate the possible involvement of the BRCA1 gene in Japanese sporadic breast cancer we have analyzed loss of heterozygosity (LOH) at the BRCA1 region (17q12-q22) in 101 sporadic breast cancers using 5 microsatellite markers, such as D17S250, D17S846, D17S855, D17S579, and NME1. The frequency of LOH in each markers was 14.9%(11/74), 11.9 %(8/67),14.3%(12/84),5.3%(4/75), and13.3%(9/68),respectively. The incidence of LOH in at least one of 5 markers was 23.8%(24/101). The LOH at the BRCA1 region did not significantly correlate with clinicopathologic factors. Despite using a microdissection method, the LOH frequency in our series was relatively lower than other reports, especially in Western countries. We suggest that the BRCA1 gene might play only a limited role as a tumor suppressor gene in the majority of Japanese sporadic breast cancers.

Journal Article↗
PubMed1996

Sequence variants of the estrogen receptor (ER) gene found in breast cancer patients with ER negative and progesterone receptor positive tumors.

Thirteen pairs of tumor and blood DNAs from breast cancer patients with estrogen receptor (ER) negative and progesterone receptor (PgR) positive tumors were screened for mutation analysis using SSCP method. Although neither germline nor somatic mutation of the ER gene in this series was detected, we found two types of sequence variants in exon 1 and exon 4, indicating two silent mutations in codon 10 (TCT to TCC) and codon 325 (CCC to CCG), respectively. These variants were recognized as polymorphic sites. Although the frequency of these polymorphic sites was not correlated with hormone receptor status, the variant in codon 325 tended to be seen more frequently in breast cancer patients than in non-cancer control cases (P = 0.057).

Base Sequence↗
PubMed1996

Microsatellite instability in in situ and invasive sporadic breast cancers of Japanese women.

We studied the timing of microsatellite instability (referred to as replication error; RER) presentation during human breast carcinogenesis using tissue microdissected from both in situ and invasive breast cancers of Japanese women. We analyzed 100 breast cancer specimens for RER at nine genomic loci on seven chromosomes. Eight of the 100 cases (8%) were RER-positive at one or more chromosomal loci. Additionally; we obtained genomic DNA from two of four RER-positive patients with an intraductal component, both of which showed microsatellite instability in in situ foci. This finding indicates that microsatellite instability may be an early event during human breast carcinogenesis.

Breast Neoplasms↗
PubMed1996

Microsatellite instability in sporadic human breast cancers.

Human breast-cancer specimens from 100 patients were analyzed for microsatellite instability (referred to as replication error; RER) at 12 genomic loci on 7 chromosomes, and results were correlated with clinicopathologic characteristics. In 42 of 100 breast-cancer patients, we investigated whether RER was associated with the amplification of oncogenes and/or suppression of tumor-suppressor genes. Of the 100 patients, 8 (8%) were RER-positive at one or more chromosomal loci. The majority of RER-positive patients had early-stage disease with ER-positive tumors, suggesting that RER occurs early in breast tumorigenesis. However, no significant correlation was observed between RER and oncogenes or tumor-suppressor genes. Thus, the mechanism of RER in sporadic human breast cancer may be independent of the multi-step carcinogenesis caused by the alterations of oncogenes and tumor-suppressor genes.

Breast Neoplasms↗
PubMed1996

Production of hydroxy fatty acid (10-hydroxy-12(Z)-octadecenoic acid) by Lactobacillus plantarum from linoleic acid and its cardiac effects to guinea pig papillary muscles.

Lactobacillus plantarum produced 10-hydroxy-12(Z)-octadecenoic acid (10-OHODA) from linoleic acid. It was suspected that 10-OHODA might be closely related to leukotoxin (9,10-epoxy-12-octa-decenoic acid (LTx)) which was regarded as a toxic and/or defensive substance in living beings. The cardiac effect of 10-OHODA, which was biosynthesized by Lactobacillus plantarum, on an isolated guinea-pig papillary muscle was determined. Its effect on the contractile force of the tissue preparations was examined both in terms of its concentration and the time of exposure. A decrease in muscular tension was observed immediately after administration of 10-OHODA at concentrations of 30, 100, and 300 microM. We also compared the effect of 10-OHODA on muscle tension with that of LTx and its isomer 12,13-epoxy-9-octadecenoic acid (LTx'). Each inhibitory effect on the contractile force of the papillary muscle was statistically significant in the concentration of 300 microM 5 min after administration compared to the control in the absence of each fatty acid, suggesting that 10-OHODA is likely to exert some influence on the circulatory system together with LTx and LTx'.

Animals↗
PubMed1996

Flow Cytometric Assay of c-erbB-2 Protein in Fine Needle Aspirates of Fresh and Frozen Human Breast Cancer Tissues.

Using FCM (flow cytometry), we analyzed the ErbB-2 (c-erbB-2 protein) status of 61 breast cancer tissue samples obtained by FNAB (fine-needle aspiration biopsy). The number of cancer cells collected by FNAB from fresh samples was 1.7+/-0.7 x10&sup5;, 2.5 +/-0.6 x10&sup5;, and 4.0+/- 0.8x10 &sup5;, by single, double and triple aspirations, respectively. A mean of 3.0+/-0.6 x10&sup5;cells was collected on three aspirations from frozen samples. The number of cells collected on three aspirations was sufficient for the measurement of ErbB-2. Cells with higher ErbB-2 levels than those of normal human lymphocytes were designated ErbB-2 positive cells. The mean overall for ErbB-2 positive cell rates was 20.5 +/- 27.9 % (mean+/-SD). The rates were 27.9 +/- 31.6 % in patients with recurrence and 15.9 +/- 24.4% in patients without recurrence. When the cut-off value was set at 20% of the positive cell rate (P =0.008, generalized Wilcoxon test), patients with ErbB-2 negative tumors showed highly significantly longer survival without recurrence (P=0.008, generalized Wilcoxontest) and better overall survival rates (P=0.013) than patients with ErbB-2 positive tumors. Among 61 specimens, 16 (26.2%) scored positive for ErbB-2 by FCM. These finding indicated that the analysis of ErbB-2 status using FCM of samples obtained by FNAB should be useful for preoperatively evaluating the prognosis of patients with breast cancer.

Journal Article↗
PubMed1996

Monoepoxide production from linoleic acid by cytochrome c in the presence of cardiolipin.

We found that cytochrome c (Cyt c) could oxidize cardiolipin (CL), and detected monoepoxides of linoleic acid (LA) in the fatty acids constituting the oxidized CL. We also found that in the presence of CL and Cyt c, free LA was oxidized and LA monoepoxides were produced. The aim of this study was to elucidate the mechanism of this lipid peroxidation. We concluded that ferric Cyt c produced some radical species from water-soluble oxygen in the presence of CL (CL-Cyt c system) and that radicals oxidized free LA or CL. The CL-Cyt c system may be another LA monoepoxide producing system in the neutrophil and may account for the lipid peroxidation observed in the ischemia-reperfusion-induced cardiac injury.

Cardiolipins↗
PubMed1996

Superoxide anion reduces the ability of myeloperoxidase to damage lipids.

The aim of this study was to determine whether lipids are damaged by myeloperoxidase (MP) not only with hydrogen peroxide (H2O2), but also with a H2O2-generating system. Using the hypoxanthine-xanthine oxidase-Cu,Zn-superoxide dismutase (HX-XO-SOD) system as an effective H2O2-generating system, we observed a reduction in the ability of MP to produce peroxylipids in the HX-XO-SOD-MP system, compared with the H2O2-MP system. We also noted that MP inhibited the production of monoepoxide by the H2O2-cytochrome c (Cyt c) system. These results suggest that MP plays a role as an absorber of active oxygen species and prevents phagocytes from self-destruction.

Cytochrome c Group↗
PubMed1996

Abundance of Gal beta 1,3GalNAc in O-linked oligosaccharide on hinge region of polymerized IgA1 and heat-aggregated IgA1 from normal human serum.

Gas-phase hydrazinolysis was used to analyze the glycoform of the O-linked oligosaccharide of human serum IgA1. In our previous report, only one glycoform was obtained from the IgA1 of healthy individuals. However, it was found to be composed of heterogeneous IgA1 components having mutually different glycoforms. First, the IgA1 was separated into two subfractions having different affinities toward jacalin. Among them, the high-affinity subfraction was mainly composed of polymerized IgA1. Comparative study of the carbohydrate chain showed a relative abundance of Gal beta 1,3GalNAc in the polymerized form. A simultaneous analysis of the N-glycan of these subfractions was also carried out. Three major components, two biantennary and one triantennary oligosaccharides, were obtained from both subfractions and the relative contents of these components were almost the same. On the other hand, IgA1 was artificially polymerized by heating at 63 degrees C for 2 h. The heat-stable IgA1 was separated from the heat-aggregated material on a Sephacryl S-300 column. The obtained heat-stable IgA1 (approximately 20%) was not further aggregated by more heating under the same conditions. The heat-stable IgA1 contained a much higher amount of the sialylated Gal beta 1,3GalNAc. Thus, it was shown that the degree of completeness of the hinge O-linked oligosaccharide might be correlated with the stability and polymerization process of the IgA1 molecule.

Acetylgalactosamine↗
PubMed1996

Estimation of the number of O-linked oligosaccharides per heavy chain of human serum IgA1 by matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) analysis of the hinge glycopeptide.

In our previous study, gas-phase hydrazinolysis was used to analyze the glycoform of the O-linked oligosaccharide of human serum IgA1. All O-linked oligosaccharide chains are known to be present in the hinge portion. However, the number of O-linked oligosaccharide chains on IgA1 remained unclear. In order to determine the number of linked sugar chains, we applied matrix-assisted laser desorption ionization time-of-flight mass spectrometry (MALDI-TOFMS) to the hinge glycopeptide prepared from human serum IgA1. MALDI-TOFMS did not show clear peaks, probably due to the microheterogeneity of the structure of each sugar chain. However, elimination of peripheral sialic acid and galactose residues by sequential treatment with neuraminidase and beta-galactosidase gave clear mass spectra with several sharp peaks. On the basis of these spectra, we conclude that IgA1 prepared from normal human serum carries different numbers of sugar chains. There are two major populations, one contains five GalNAc residues and the other four GalNAc residues. On the other hand, the hinge glycopeptide prepared from myeloma IgA1 was composed mainly of one population containing four GalNAc residues. Earlier, we reported incomplete glycosylation of IgA1 isolated from the serum of an IgA1 myeloma patient. In this experiment, the presence of four O-linked oligosaccharides per heavy chain of IgA1 from a myeloma patient was found. The reason why only four out of five sites on the hinge glycopeptide were fully glycosylated in the IgA1 from the IgA1 myeloma patient is not clear.

Amino Acid Sequence↗
PubMed1996

Eleven-year survey of safety and efficacy of endoscopic injection sclerotherapy using 2% sodium tetradecyl sulfate and contrast medium.

We conducted a retrospective 11-year survey to evaluate the post-treatment course in 285 patients with esophagogastric varices following administration of endoscopic injection sclerotherapy as an emergency, elective, or prophylactic procedure using freshly prepared 2% sodium tetradecyl sulfate not containing benzyl alcohol. These agents were injected into the varices and the supplying veins under fluoroscopic observation, usually in a single treatment. In all patients the variceal size was greatly reduced following one treatment. The amount of sclerosant necessary to fill the varices and the supplying veins varied widely among the patients. Acute variceal bleeding was controlled in 80 (96.4%) of the 83 patients, and the risk of rebleeding during the first month was 0.0548 in the emergency procedures. The serious complication of perforation was observed in one patient. The cause of death was established in the 122 patients who died and included esophageal variceal bleeding in eight (6.6%) and gastric variceal bleeding in one (0.8%). The overall 50% survival period was 5 years and 4 months. Multivariate analysis disclosed that the factors with the greatest negative effect on survival were poor hepatic status and the presence of hepatocellular carcinoma. The method of preparation and the procedure itself may be considered safe and effective in the treatment of esophagogastric varices.

Aged↗
PubMed1996

Production of matrix metalloproteinases and tissue inhibitors of metalloproteinases in human breast carcinomas.

We examined production and tissue localization of matrix metalloproteinase (MMP)-1 (tissue collagenase), MMP-2 (gelatinase A), MMP-3 (stromelysin-1), MMP-9 (gelatinase B), tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in human breast carcinomas. In more than half of the cases, MMP-1, MMP-2, MMP-9, TIMP-1 and TIMP-2 were immunolocalized in carcinoma cells and MMP-2 was on the carcinoma cell membranes as well, whereas MMP-3 was positively stained in less than 15% of the cases. MMP-1 staining in carcinoma cells was significantly higher in scirrhous carcinoma than in other types of carcinoma. MMP-9 expression was remarkably higher in the carcinoma cases with lymphnode metastasis than in the non-metastatic cases. MMP-3 was mainly expressed in T-lymphocytes infiltrated in the tumor stroma. Stromal fibroblasts were positive for all these MMPs except for MMP-3. The TIMP-1 levels released into the culture media by carcinoma tissues were significantly lower than those by fibroadenoma tissues, although there were no significant differences in the levels of MMP-1, MMP-2, MMP-9 and TIMP-2. Gelatin zymographical analyses showed that the activation rate of the zymogen of MMP-2 (proMMP-2) is significantly higher in the more advanced carcinoma group with lymphnode metastasis than in the metastasis-negative and fibroadenoma groups. These data indicate that MMP-1, MMP-2 and MMP-9 are highly expressed in human breast carcinoma tissue and suggest that activation of proMMP-2 may be an indicator of lymphnode metastasis of the breast carcinoma.

Breast Neoplasms↗