Search PubMed⌕ Search

Biomedical subjects

S Satomi

Publications and source records attributed to S Satomi.

At least 91 records · Page 5Linked to original sources
PubMed1998

Effect of valine-depleted total parenteral nutrition on fatty liver development in tumor-bearing rats.

Valine-depleted amino acid imbalance, while having a suppressive effect on tumor growth, may induce fatty liver. We administered valine-depleted total parenteral nutrition (TPN) solution to rats subcutaneously transplanted with ascites containing hepatoma AH-109A and examined the time course of the development of fatty liver. An accumulation of fatty vacuoles was observed in hepatocytes on day 4. To prevent the development of fatty liver in tumor-bearing rats, we administered a small amount of valine in addition to the valine-depleted imbalance solution via the central vein. Such treatment, however, resulted in neither the prevention of fatty liver development nor the suppression of tumor growth. To supply valine to the liver, we administered a low concentration of valine via the portal vein simultaneously with central venous administration of valine-depleted TPN solution. As a result, the peripheral blood valine level of these rats was < 0.5 that of the control group, but the valine in the liver was maintained at the same level as that of the control group, and accumulation of triacylglycerols in the liver was slight. However, the suppressive effect on tumor growth was maintained, as the tumor weight was suppressed to almost the same degree as that of rats administered only the valine-depleted solution.

Amino Acids↗
PubMed1998

Defective IL-2-mediated IL-2 receptor alpha chain expression in Stat3-deficient T lymphocytes.

Stat3, a member of signal transducers and activators of transcription (STAT), is activated by a variety of cytokines. Recently, mice lacking Stat3 specifically in T cells have been generated and shown to be defective in IL-6-induced proliferation due to the impairment in IL-6-mediated prevention of apoptosis. In the present study, we show that Stat3-deficient T cells are partially defective in IL-2-induced proliferation. Stat3-deficient T cells show impaired IL-2-mediated IL-2 receptor (IL-2R) alpha chain expression. When Stat3-deficient T cells are stimulated with high-dose IL-2, these T cells express IL-2Ralpha and proliferate to similar extents as wild-type T cells. These demonstrate that Stat3 activation is required for efficient T cell proliferation by IL-2 through IL-2Ralpha induction. Taken together, these findings demonstrate that Stat3 activation in T cells is responsible for IL-2- and IL-6-induced proliferation through distinct mechanisms.

Animals↗
PubMed1998

Prolongation of allograft survival by administration of mAb specific for the three subunits of IL-2 receptor.

The IL-2 receptor (IL-2R) gamma chain, the so-called common gamma (gamma(c)) chain, which is shared with multiple cytokine receptors, plays important roles in the immune system. Here we assessed the immunosuppressive ability of mAb specific for the gamma(c) chain in induction of cytotoxic T lymphocytes (CTL) and allograft rejection in combination with mAb specific for the alpha and beta chains of IL-2R. CBA/N (H-2k) mice were injected i.p. with allogeneic splenocytes from BALB/c (H-2d) mice, and then administered with combinations of anti-IL-2R alpha, anti-IL-2R beta and anti-gamma(c) mAb or a control mAb. Addition of anti-gamma(c) mAb together with anti-IL-2R alpha and anti-IL-2R beta mAb induced a complete inhibition of CTL response. The numbers and populations of CD4+ CD8- and CD4- CD8+ T cells were not significantly affected by administration of the three anti-IL-2R mAb, whereas NK cells were completely depleted in spleens of mice treated with the anti-IL-2R mAb. Furthermore, skin allograft survival was also significantly prolonged by administration of the three anti-IL-2R mAb. These results suggest that the anti-gamma(c) mAb in combination with anti-IL-2R alpha and anti-IL-2R beta mAb is capable of suppressing induction of CTL and NK cells, resulting in prolongation of skin allograft survival.

Animals↗
PubMed1998

Nonsense mutation at codon 63 of the BRCA1 gene in Japanese breast cancer patients.

The involvement of abnormalities of the BRCA1 gene in breast cancers in Japanese patients without any family history of this cancer was investigated by polymerase chain reaction-based single-strand conformation polymorphism analysis of the DNA sequences corresponding to the zinc finger domain (exons 2, 3 and 5) and the binding domain with Rad51 (exon 11) of the BRCA1 protein. An identical nonsense mutation at codon 63 (TTA to TAA) was found in 2 of 56 (3.5%) breast cancers from independent patients. The nucleotide change was also detected in the DNAs from non-cancerous tissues of both patients and therefore was a germline mutation. One of the patients was a member of a pedigree involving 3 ovarian cancer and 1 gastric cancer patients, while the other patient had no family history of malignancy. The same germline mutation at codon 63 was reported in four other independent Japanese pedigrees with frequent breast cancer, but not in such families in other countries. These observations suggest that the mutation commonly originated from a single Japanese ancestor. No other mutation of the BRCA1 gene was observed in the samples analyzed in this study. A low incidence of germline mutation and the absence of somatic mutation suggest that the aberration of the BRCA1 gene is involved only in a subset of Japanese breast cancers.

Aged↗
PubMed1998

Experimental ablation of emphysematous rat lung with Nd: YAG laser: lung changes studied by histopathology and SEM.

Laser ablation has been employed as a therapeutic measure for chronic pulmonary emphysema. As yet, however, its effect is not understood on firm pathological basis. We aimed to study, both histopathologically and using Scanning Electric Microscopy (SEM), the changes produced by irradiation with contact Neodymium-yttrium aluminum garnet laser (Nd: YAG laser) in rat lungs with experimentally induced emphysema. Emphysema was produced in 34 rats by instilling elastase via airways. Eight weeks after the instillation, the emphysematous left lung was irradiated under thoracotomy with contact Nd: YAG laser at a power of 5 watts. The animals were sacrificed in acute as well as chronic phase for histopathological observation of lung and scanning electron microscopy. Laser caused necrotic and inflammatory changes in the subpleural zone of lung. Immediately after irradiation, the alveolar septa were destroyed as visualized by SEM, only leaving the elastic skeleton. In a chronic phase, the necrotic zone was collapsed and replaced with a thick fibrous scar which seemed to serve more or less to keep the organ from being excessively inflated. In this model, irradiation induces subpleural dense scarring, which, by "encasing" an emphysematous lung, is expected to more or less normalize the excessive compliance.

Animals↗
PubMed1998

[Frequent loss of heterozygosity on the long arm of chromosome 21 in human esophageal, squamous cell carcinoma].

We investigated human esophageal squamous cell carcinoma using microsatellite markers on the long arm of chromosome 21 (21q) and found frequent loss of heterozygosity (LOH). The frequency of LOH was more than 50% in most of the microsatellite markers examined. Whole chromosome deletion suspected cases were observed in 25% of all cases. No case with microsatellite instability was found. Three common regions of allelic loss were identified. The frequent LOH was observed from early stage in pTNM classification. An unknown tumor suppressor gene in the genesis of esophageal squamous cell carcinoma may exist in 21q.

Carcinoma, Squamous Cell↗
PubMed1998

Matrix metalloproteinase-mediated extracellular matrix protein degradation in human pulmonary emphysema.

The aim of this study was to investigate the extracellular degrading proteolytic cascade proteins referred to as matrix metalloproteinase-1 (MMP-1), MMP-2, MMP-9, membrane-type matrix metalloproteinase-1 (MT1-MMP), tissue inhibitors of matrix metalloproteinase-1 (TIMP-1), TIMP-2, neutrophil elastase, and alpha1-antitrypsin in human pulmonary emphysema. Localization of MMP-1, MMP-2, MMP-8, MMP-9, MT1-MMP, TIMP-1, and TIMP-2 was verified by immunohistochemical analysis. The results of our study indicated that the immunoreactivity of MMP-1, MMP-8, MMP-9, and TIMP-1 was absent, whereas MT1-MMP and MMP-2 were mainly observed in pneumocytes, fibroblasts, and alveolar macrophages. Although MT1-MMP and MMP-2 were observed both in emphysematous and normal lung tissue, these immunoreactivities were intense in the emphysematous samples. The presence of MMP-1, MMP-2, MMP-9, TIMP-1, and TIMP-2 was confirmed at mRNA level by reverse transcription-PCR analysis and enzyme immunoassay (EIA). However, the only statistical difference that was observed was in MMP-2 and MMP-9 (MMP-2: emphysematous samples, 19.1+/-2.1 versus control samples, 5.2+/-0.60 microg/g protein, p < 0.05; MMP-9: emphysematous samples, 18.4+/-5.6 versus control samples, 8.1+/-2.7 microg/g protein, p < 0.05). Results of the neutrophil elastase as analyzed by EIA, and alpha1-antitrypsin levels as detected by laser nephelometric immunoassay, indicated no statistical difference between the emphysematous and control groups. In addition to the presence of mRNA levels, the level of MT1-MMP according to immunoblot analysis increased in the emphysematous samples. Gelatin zymographic analysis confirmed the presence of both pro and active forms of MMP-2, and the increased ratio of the active form of MMP-2 in emphysematous samples (25.9%+/-2.0% versus 11.2%+/-3.3%, p < 0.05), indicated in situ activation of MMP-2 by MT1-MMP. Elastin zymographic analysis showed elastolytic activity by MMP-2 and MMP-9 but not the reported band of macrophage metalloelastase (MMP-12). The data suggest that the MT1-MMP/MMP-2/TIMP-2 system plays a significant role in the MMP-mediated extracellular matrix degradation and tissue remodeling of emphysematous lungs, and thus may contribute to the weakening of lung parenchyma and lead to the formation of emphysema.

Aged↗
PubMed1998

Comparative study of sialidase activity and G(M3) content in B16 melanoma variants with different metastatic potential.

We previously demonstrated that transfection of a sialidase cDNA into B16-BL6 cells, a highly metastatic and invasive cell line derived from the mouse B16 melanoma, resulted in a marked suppression of metastasis accompanied by decreased cellular content of the GM3 that is one of the target molecules of the sialidase expressed (Tokuyama et al., 1997 Int. J. Cancer, 73, 410-415). To obtain further insight into the involvement of sialidase in metastasis, we made a comparison of the levels of sialidase activity and GM3 content between B16 melanoma cell lines with low (B16-F1) and high (B16-F10 and -BL6) metastatic potential. The cells exhibited sialidase activity towards 4-methylumbelliferyl N-acetylneuraminic acid (4MU-Neu5Ac) and gangliosides at acidic pH in the particulate fractions, but not in the cytosol. The activity toward 4MU-NeuAc was significantly lower in highly metastatic cells. The activity toward gangliosides, on the other hand, varied independently of metastatic potential: B16-F10 cells with a high potential for experimental metastasis showed the lowest level and B16-BL6 cells having high invasiveness had rather a higher level of ganglioside sialidase along with a much greater GM3 synthase activity than the other two cell lines. Flow cytometric analysis with anti-GM3 antibody revealed that highly metastatic cell lines were higher in the binding affinity as compared to B16-F1 cells, B16-BL6 cells containing twice as much cellular GM3 as B16-F1 cells on thin-layer chromatography.

Animals↗
PubMed1997

Breast-Coserving Surgery for Primary Breast Cancer: Immediate Volume Replacement Using Lateral Tissue Flap.

We have developed a breast-conserving surgery consisting of quadrantectomy and regional lymph node dissection and immediate volume replacement using lateral tissue flap (LTF). The quadrantectomy was employed on the basis of segmental anatomy of the duct-lobular system in which breast carcinoma originates. Lateral skin incision was performed from the apex of mid-axillary line to the inframammary fold, without removing the skin overlying the tumor, In the early period of breast reconstruction embraced latissmus dorsi flap (LDF) for 10 patients(reconstruction was not performed on 35 patients), but in the late period we employed LTF for 56 patients. Four of the 101 patients developed ipsilateral breast cancer during a mean follow-up period of 48 months, but none died of breast cancer, Among the 56 patients with LTF replacement no patient developed ipsilateral breast cancer. Fairly good cosmetic outcome was obtained in the patients who underwent the immediate volume replacement. Breast-conserving surgeries are reviewed, and the surgical procedure using LTF for immediate volume replacement is described.

Journal Article↗
PubMed1997

The protooncogene product, PEBP2beta/CBFbeta, is mainly located in the cytoplasm and has an affinity with cytoskeletal structures.

The Pebpb2/Cbfb gene encodes the non-DNA binding beta subunit of the heterodimeric transcription factor, PEBP2/CBF, and has been implicated in a subtype of human acute myeloid leukemia, as well as being indispensable for the development of definitive hematopoiesis in the murine fetal liver. By examining a subcellular localization of the PEBP2beta/CBFbeta protein in tissue culture cells, we could reveal an additional aspect of the protein other than to be a subunit of a transcription factor. Immunoblot and immunocytochemical staining showed that PEBP2beta/CBFbeta was mostly present in the cytoplasm. This PEBP2beta/CBFbeta was free from its DNA-binding partner, the alpha subunit of PEBP2/CBF, as judged by the electrophoretic mobility shift assays. Furthermore, a significant amount of PEBP2beta/CBFbeta was retained in the cytoskeleton preparation after detergent extraction of the cells and was found by double immunofluorescence to colocalize with the F-actin on stress fibers and the vinculin in membrane processes. Thus, the present study extends PEBP2beta/CBFbeta to be a cytoskeleton-affinitive as well as nuclear protein. The implications of these results are discussed.

3T3 Cells↗
PubMed1997

Characterization and In Vitro Cytotoxic Effect of Adriamycin-conjugated Monoclonal Antibody Prepared Against Breast Cancer Cell Line.

We have produced an adriamycin-conjugated monoclonal antibody, AM1, covalently linked by acid-labile cis-aconitic spacer. The immunoconjugate, cis-aconitic adriamycin(cAA)-AM1, was confirmed to retain the binding activity against human breast cancer cell lines by flow cytometry. The immunoconjugate was shown to be internalized into antigen-positive cancer cells by flow cytometry analysis and high performance liquid chromatography. Antitumor effects of cAA-AM1 were assessed on human breast cancer and colon cancer cell lines, with inhibition of (3) H-leucine uptakes to the cells. cAA-AM1 demonstrated a selective cytotoxicity to ZR-75-1 which was reactive with AM1, whereas it showed no antitumor effect on SW1116 cells which did not react with AM1. Free adriamycin demonstrated a non-selective cytotoxicity against both cell lines. AM1 alone and cAA-control IgM did not show any antitumor effect on ZR-75-1. These results suggest that cAA-AM1 retains binding activity and specificity against breast cancer cells in vitro.

Journal Article↗
PubMed1997

Frequent gains on chromosome arms 1q and/or 8q in human endometrial cancer.

Comparative genomic hybridization (CGH) was employed to survey genomic regions with increased and decreased copy number of the DNA sequence in 15 endometrial cancers [10 cases with microsatellite instability positive (MI+) and 5 cases with MI-]. Twelve of these 15 tumors (80%) showed abnormalities in copy number at one or more of the chromosomal regions. There were no regions with frequent chromosomal losses. Conversely, 11 of 15 cases (73%) showed gains on chromosome arms 1q (8/15; 53%) and/or 8q (6/15; 40%). Concordant gains of both chromosome arms 1q and 8q were observed in all three endometrial cancers of histological grade 3. These results suggest that these two chromosomal regions may contain genes whose increased expression contributes to development and/or progression of endometrial carcinogenesis. Two cases were further analyzed by fluorescence in situ hybridization (FISH) using three probes on chromosome 1 and two probes on chromosome 8 to more accurately determine increases in copy number. We found gains of chromosome 1q to 2.9-3.6 copies per cell and on 8q to 4.4 copies per cell.

Chromosome Aberrations↗
PubMed1997

Liver transplantation for severe hypoxemia caused by patent ductus venosus.

The authors describe the case of a 9-year-old girl who underwent liver transplantation because she suffered from severe hypoxemia caused by patent ductus venosus (PDV). Generally, severe hypoxemia (PaO2 < 50 mm Hg in room air or < 300 mm Hg in pure oxygen) is not an indication for liver transplantation because the hypoxemia may not be improved, and may lead to a fatal outcome. PDV, which is associated with mild liver dysfunction, is not an indication for liver transplantation by itself. But in our patient, most of the mesenteric venous flow directly entered the systemic circulation through the PDV just like the portosystemic shunt, and this caused the pulmonary arteriovenous shunt and hypoxemia. Thus, the authors operated on the patient in an attempt to restore her pulmonary function. Nitric oxide (10 to 20 ppm) was added to the inhaled gas to dilate the functional pulmonary capillaries and to deliver sufficient oxygen after the transplantation. Although the patient suffered various complications after the operation, the final results were excellent.

Angiography, Digital Subtraction↗