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Biomedical subjects

J Fujimoto

Publications and source records attributed to J Fujimoto.

At least 55 records · Page 3Linked to original sources
PubMed2001

Nitrobenzylthioinosine (NBT), a nucleoside transport inhibitor, protects against Shiga toxin cytotoxicity in human microvascular endothelial cells.

Infections with Shiga toxin (Stx)-producing Escherichia coli (STEC) cause microvascular endothelial cell damage, resulting in hemorrhagic colitis and hemolytic uremic syndrome. The prevention of endothelial cell damage is therefore a crucial step in overcoming this disorder. Here, we report that nitrobenzylthioinosine (NBT), a nucleoside transport inhibitor, has a protective effect against the cytotoxicity of Stxs in human microvascular endothelial cells (HMVECs). The relative viability of cells treated with 1.5-15 pM of Stx1 was reduced to 10-20% of that without Stx1. However, the viability of cells treated with NBT (10-100 microM) remained higher than 80%, even in the presence of Stx1. NBT also protected against Stx1 cytotoxicity in sodium butyrate-treated hypersensitive HMVECs. The protective effect of NBT against Stx cytotoxicity may be due to the depletion of ATP in the cells, thereby inhibiting the entry of Stx1.

Adenosine Triphosphate↗
PubMed2001

[Persectives on postgenome medicine: Gene therapy for liver cirrhosis].

Liver cirrhosis is the irreversible end result of chronic liver disease, characterized by diffuse disorganization of the normal hepatic structure of regenerative nodules and fibrotic tissue. It is associated with prominent morbidity and mortality, and is induced by many factors. The ideal strategy for the treatment of liver cirrhosis should include prevention of fibrogenesis, stimulation of hepatocyte mitosis, and reorganization of the liver architecture. We have developed a novel gene therapy approach for rat liver cirrhosis by muscle-directed gene transfer of hepatocyte growth factor(HGF). HGF gene transduction inhibited fibrogenesis and hepatocyte apoptosis, and also produced resolution of fibrosis in the cirrhotic liver. Thus, HGF gene therapy may be potentially useful for the treatment of patients with liver cirrhosis, which is otherwise fatal and untreatable by conventional therapy.

Animals↗
PubMed2001

Inhibitory effect of ginsenoside-Rb2 on invasiveness of uterine endometrial cancer cells to the basement membrane.

Ginsenoside-Rb2 derived from ginseng inhibited invasiveness to the basement membrane of endometrial cancer cell lines Ishikawa. HHUA and HEC-1-A cells. These cells dominantly expressed matrix metalloproteinase (MMP)-2 (gelatinase A) among MMPs by zymography. Ginsenoside-Rb2 suppressed the expression and activity of MMP-2, but did not alter the expression of tissue inhibitors of metalloproteinase (TIMP)-1 and TIMP-2 in the cells. Therefore, ginsenoside-Rb2 might inhibit invasiveness to the basement membrane via MMP-2 suppression in some endometrial cancers, and can be used as a medicine for inhibition of secondary spreading of uterine endometrial cancers.

Antineoplastic Agents↗
PubMed2001

Herbal complex suppresses telomerase activity in chemo-endocrine resistant cancer cell lines.

A herbal complex consisting of Hoelen, Angelicae radix, Scutellariae radix and Glycyrrhizae radix suppressed cell viability and telomerase activity in hormone-refractory and chemo-resistant cancer cell lines, namely poorly differentiated uterine endometrial cancer cell line AN3 CA, adriamycin-resistant breast cancer cell line MCF7/ADR and cisplatin-resistant ovarian cancer cell line A2780. Furthermore, the herbal complex suppressed the expression of the full length of human telomerase reverse transcriptase (hTERT), which is related to telomerase activity. This indicates that the herbal complex can suppress the tumor growth of chemoendocrine resistant cancers, at least in part via suppression of telomerase activity associated with down-regulated hTERT.

Antineoplastic Agents↗
PubMed2000

Steroid receptors and metastatic potential in endometrial cancers.

The relative overexpression of estrogen receptor (ER)-alpha exon 5 splicing variant, the disrupted synchronization of ER-beta and ER-alpha expressions, and the suppression of progesterone receptor (PR) form A expression as a transcriptional repressor might be related to metastatic potential of uterine endometrial cancers, leading to poor patient prognosis related to estrogen refractoriness.

Alternative Splicing↗
PubMed2000

The value of platelet-derived endothelial cell growth factor as a novel predictor of advancement of uterine cervical cancers.

Serum platelet-derived endothelial cell growth factor (PD-ECGF) in patients with uterine cervical cancers revealed a significantly positive correlation with clinical stage and tumor size and with the advancement indicators lymph node metastasis, parametrial involvement, and vessel permeation in both squamous cell carcinomas and adenocarcinomas. The prognosis of the patients with high serum PD-ECGF was extremely poor, whereas the 36-month survival rate of the other patients with low serum PD-ECGF was 81.3% in squamous cell carcinomas and 80.0% in adenocarcinomas. Our data indicate that serum PD-ECGF levels reflect the status of advancement of uterine cervical cancers and thus may be recognized as a novel tumor marker for both squamous cell carcinomas and adenocarcinomas of the uterine cervix.

Adult↗
PubMed2000

Clinical implications of expression of interleukin 8 related to angiogenesis in uterine cervical cancers.

There was a significant correlation between microvessel counts and interleukin (IL)-8 levels and between infiltrated macrophage counts and IL-8 levels in uterine cervical cancers. Immunohistochemical staining revealed that the localization of IL-8 was similar to that of CD68 for macrophages. The prognosis of the 20 patients with high IL-8 (>1000 pg/mg protein) in uterine cervical cancers was extremely poor, whereas the 24-month survival rate of the other 60 patients with low IL-8 (<1000 pg/mg protein) was 67%. Therefore, this indicates that IL-8 might be a prognostic indicator as an angiogenic factor supplied from macrophages within and around the tumor.

Adenocarcinoma↗
PubMed2000

DNA hypermethylation at the pS2 promoter region is associated with early stage of stomach carcinogenesis.

pS2, a member of the trefoil peptide family, has been suggested to be a gastric-specific tumor suppressor. We examined the expression of pS2 in gastric carcinomas, adenomas and non-neoplastic mucosa and analyzed the DNA methylation in the pS2 promoter. Reduced expression of pS2 was frequently associated with well-differentiated adenocarcinomas. The CpG sites within the promoter region of the pS2 gene were methylated in pS2-negative gastric carcinoma cell lines whereas it was not in pS2-positive cell line. The promoter methylation was detected in gastric carcinoma tissues and intestinal metaplasia with reduced pS2 expression whereas none of the carcinomas with preserved pS2 expression showed the promoter methylation. These findings suggest that reduced expression of pS2 due to the promoter methylation may participate in an early stage of stomach carcinogenesis, especially of well differentiated type.

Biomarkers, Tumor↗
PubMed2000

Long-term overexpression of human granulocyte colony-stimulating factor in transgenic mice: persistent neutrophilia with no increased mortality for more than one year.

To investigate possible adverse consequences of persistent neutrophil overproduction, mice transgenic for human granulocyte colony-stimulating factor (hG-CSF) were studied for more than 1 year. They showed marked granulocytopoiesis and neutrophilia. Continuous medullary and extramedullary granulocytopoiesis resulted in marked changes in bone and liver. In the liver, haemorrhage and focal necrosis and a few haemangiosarcomas were present, presumably caused by the destructive granulocytopoiesis. Despite the high incidence of lung infiltration by mature neutrophils, lung lesions rarely appeared. Although there was a persistent increase in neutrophils, mortality of the mice did not differ from that of non-transgenic littermates at least within 1 year after birth. Factors other than overproduction of G-CSF and extensive neutrophilia could be required for the development of neutrophil-mediated acute and chronic tissue damage.

Animals↗
PubMed2000

Optical coherence tomography as a method for identifying benign and malignant microscopic structures in the prostate gland.

OBJECTIVES: Optical coherence tomography (OCT) is a new optical imaging technique capable of providing cross-sectional imaging of tissue microstructure in vivo and in real time. OCT was used in the setting of the human prostate ex vivo, and the images acquired were compared with those obtained using standard histopathologic methods. METHODS: Multiple samples (3 to 6) were obtained from the radical prostatectomy specimens of 7 men with clinically localized (T1c-2, N0, M0) adenocarcinoma of the prostate. These specimens were 1 cm in length and 1 mm x 1 mm in rectangular cross section. Specimens were first imaged using OCT and then embedded and stained in preparation for histopathologic evaluation. Co-registration of the images obtained using OCT and standard histopathologic evaluation provided the basis for comparison. RESULTS: Structural architecture on the order of 50 to 150 microm within benign glandular epithelium, fibroadipose tissue, and malignant glandular epithelium could be resolved to a depth of approximately 0.5 mm using OCT. CONCLUSIONS: Microscopic resolution is possible in human prostatic tissue using OCT. Further studies using this technique to improve the detection and staging of adenocarcinoma of the prostate are ongoing.

Adenocarcinoma↗
PubMed2000

Functional conservation of platelet glycoprotein V promoter between mouse and human megakaryocytes.

OBJECTIVE: In an attempt to clarify the megakaryo-specific regulatory mechanism of GPV gene transcription, we characterized the 5'-flanking region of the mouse GPV gene. MATERIALS AND METHODS: The promotor activity of a -481/+22 5'-fragment of the mouse GPV gene was examined in normal mouse bone marrow cells (BMC) and various human cell lines using two distinct reporter gene assay systems, luciferase and green fluorescence protein (GFP). RESULTS: When a DNA construct consisting of this fragment and a GFP reporter gene were transiently expressed in thrombopoietin-supported mouse BMC culture, GFP was identified only in megakaryocytes. The same construct expressed high levels of GFP in the human megakaryocytic Dami line. When assessed by dual luciferase assay, the full -481/+22 fragment could drive variable promoter activity in human as well as mouse megakaryocytic lines but did not work in non-megakaryocytic cells. Sufficient transcriptional activation of this fragment was restricted to the cells expressing apparent GPV mRNA. A deletion and point mutation study indicated that GATA and Ets motifs, typical cis-acting elements for platelet-specific genes, located of -75 and -46, respectively, were essential for promoter function. CONCLUSION: The GPV promoter has the general characteristics found in platelet-specific genes, and the mechanism for megakaryocyte-specific, maturation-dependent regulation of GPV gene transcription is highly conserved between mouse and human. Analysis of GPV transcription mechanism utilizing human lines as well as BMC should provide new information on the final maturational process of megakaryocytes.

Animals↗
PubMed2000

Globotriaosyl ceramide (CD77/Gb3) in the glycolipid-enriched membrane domain participates in B-cell receptor-mediated apoptosis by regulating lyn kinase activity in human B cells.

The role of CD77 expressed on a fraction of germinal center B cells, also known as glycosphyngolipid Gb3, and as a functional receptor for Shiga toxins (Stx) in B-cell receptor (BCR)-mediated apoptosis was investigated. Using Stx1-sensitive Burkitt's lymphoma Ramos cells as an in vitro model of CD77(+) germinal center B cells, intracellular signaling events mediated by either Stx1 or anti-CD77 antibody were examined immunobiochemically and immunocytologically. We observed prompt activation of Lyn and Syk kinases leading to increased binding of these proteins to surface IgM (sIgM) in Ramos cells after Stx1 treatment. We also observed microscopic colocalization of CD77 and sIgM after stimulation with Stx1. Along with the synergism between the cross-linking of CD77 and that of sIgM in their effect on apoptosis induction, it was highly probable that CD77 cross-linking induces activation of the BCR signaling cascade. Analysis using sucrose density gradient centrifugation suggested that Stx1 binding to CD77 induced recruitment and activation of Lyn in the glycolipid-enriched membrane (GEM) fractions. Once activated, however, Lyn seemed to acquire an increased detergent solubility and moved outside of the GEM fractions. This study describes the participation of the GEM domain in BCR-signaling cascade and suggests a possible role of CD77 as a regulator of BCR-induced apoptosis in human B cells.

Apoptosis↗
PubMed2000

Characteristic expression of Hck in human B-cell precursors.

OBJECTIVE: To identify molecules involved in signaling for early B-cell development, we investigated the expression of signal transduction-related proteins in B-cell progenitors. MATERIALS AND METHODS: [corrected] Normal as well as leukemic B-cell progenitors were examined by immunoblotting and immunofluorescence study. RESULTS: [corrected] In a survey of the expression of a broad range of signal transduction molecules, the Src-family protein tyrosine kinases were found to be differentially expressed in early B-cell differentiation. [corrected] Analysis of freshly prepared precursor-B acute lymphoblastic leukemia cells and B-lineage cell lines showed Hck and Lyn are major Src-family protein tyrosine kinases expressed in this type of leukemic blasts. [corrected] However, heterogeneity of Hck and Lyn expression was found in these cells, and precursor-B acute lymphoblastic leukemia cells subsequently were classified according to the expression pattern of Hck and Lyn as Hck/Lyn dual-negative, Hck-predominant, Hck/Lyn dual-positive, and Lyn-predominant. Further studies on normal B-lineage cells indicated that the Src-family protein tyrosine kinases are expressed sequentially in a differentiation-dependent fashion during B-cell ontogeny and that the predominant expression of Hck is a common feature in B-cell progenitors, whereas Lyn expression is more significant in mature B cells. CONCLUSIONS: Although the biologic significance remains unknown, sequential expression of Src-family protein tyrosine kinases should play a role in regulation of early B-cell differentiation.

Antigens, CD↗
PubMed2000

Steroid receptors and metastatic potential in endometrial cancers.

The relative overexpression of oestrogen receptor (ER)-alpha exon 5 splicing variant (ER-alpha E5SV), ER-beta and progesterone receptor (PR) from B (PR-B) without transcriptional repression by PR from A (PR-A) might be related to the metastatic potential and partially cause deviation from sex steroidal dependency in endometrial cancers.

Endometrial Neoplasms↗
PubMed2000

Graft-versus-host-disease-associated donor cell engraftment in an F1 hybrid model is dependent upon the Fas pathway.

The graft-versus-host disease (GVHD) generated in BDF1 mice by the injection of spleen cells from the C57BL/6 parental strain induces a direct cell-mediated attack on host lymphohaematopoietic populations, resulting in the reconstitution of the host with donor cells. We examined Fas-Fas ligand (FasL) interactions in donor and host haematopoietic cells over a prolonged period of parental-induced GVHD. Fas expression on bone marrow cells of both donor and host origin increased at 2 weeks. Host cell incubation with anti-Fas antibody induced apoptosis, and the number of haematopoietic progenitor cells decreased. Fas-induced apoptosis by the repopulating donor cells, however, did not increase until 12 weeks, when more than 90% of the cells were donor cells. The expression of various cytokines, such as interferon-gamma (IFN-gamma) and tumour necrosis factor-alpha (TNF-alpha), and FasL gene expression in the bone marrow increased concomitantly. To examine directly whether FasL has a major role in the development of donor cell engraftment, FasL-deficient (gld) mice were used as donors. Injection of B6/gld spleen cells induced significantly less host lymphohaematopoietic depletion, resulting in a failure of donor cell engraftment. Furthermore, injection of IFN-gamma gene knockout (gko) B6 spleen cells failed to augment Fas and FasL expression in recipient mice, resulting in a failure of donor cell engraftment. This suggests that the induction of apoptosis by Fas-FasL interactions in host cells may contribute to a reconstitution of the host with donor cells and that donor-derived IFN-gamma plays a significant role for Fas-FasL interactions in host cells during parental-induced GVHD.

Animals↗
PubMed2000

Gene therapy for liver cirrhosis.

Liver cirrhosis is the irreversible end result of chronic liver disease and is characterized by fibrous scarring and hepatocellular regeneration. It is a major cause of morbidity and mortality worldwide and is induced by factors such as chronic hepatitis virus infection, drug abuse and alcohol abuse. The ideal strategy for the treatment of liver cirrhosis should include prevention of fibrogenesis, stimulation of hepatocyte mitosis and reorganization of the liver architecture. Hepatocyte growth factor (HGF) gene therapy has been investigated in a rat model of liver cirrhosis. In rats with lethal liver cirrhosis produced by dimethylnitrosamine, repeated transfection of the HGF gene into skeletal muscle induced a high plasma level of HGF and tyrosine phosphorylation of the c-Met/HGF receptor. Hepatocyte growth factor gene transduction inhibited fibrogenesis and hepatocyte apoptosis and also produced resolution of fibrosis in the cirrhotic liver. Hepatocyte growth factor gene therapy may have the potential to be useful for the treatment of patients with liver cirrhosis.

Animals↗
PubMed2000

Characterization of monoclonal antibodies against mouse and rat platelet glycoprotein V (CD42d).

The mouse- and rat-platelet-specific hamster monoclonal antibody (MAb) 1C2, previously found to react with a thrombin-sensitive 74-kD glycoprotein, was now shown to recognize platelet glycoprotein V (GPV, CD42d). 1C2 reacted with NIH-3T3 cells in which recombinant mouse or rat GPV was expressed. Both 1C2 and 4A5, another mouse-platelet-specific rat MAb, immunoprecipitated GVP, although they recognized different epitopes. Side-by-side comparison confirmed that 1C2 as well as RPM.9, a MAb against rat GPV, recognized the same rat platelet molecule. In a mouse bone marrow culture, 1C2+ megakaryocytes emerged from CD41 (GPIIb)+1C2- megakaryocytes. Because 1C2+ megakaryocytes exhibited higher DNA ploidy distribution than CD41+ cells, GPV likely appears in the late stage of megakaryocyte maturation. This study established 1C2 as a MAb against mouse and rat GPV, namely CD42d, and as useful tool to study rodent megakaryopoiesis.

Animals↗