Biomedical subjects

Y Myoken

Publications and source records attributed to Y Myoken.

29 records · Page 2Linked to original sources

PubMed1995

Oral Fusarium infection in a granulocytopenic patient with acute myelogenous leukemia: a case report.

The fungus Fusarium moniliforme causes fusariosis, which can be invasive and fatal in immunocompromised patients. We report a case of oral Fusarium infection in a granulocytopenic patient with acute myelogenous leukemia who developed necrotic ulceration of the gingiva, extending to the alveolar bone, but was otherwise free of any active systemic lesions. Fusarium moniliforme was identified, by histopathology and culture, to be present in the lesion and was deduced to be the causative organism for this invasive oral infection.

Acute Kidney Injury↗

PubMed1995

Immunohistochemical localization of fibroblast growth factor-1 (FGF-1) and FGF-2 in cultured human ameloblastoma epithelial cells and ameloblastoma tissues.

Fibroblast growth factor-1 (FGF-1) and FGF-2 are mitogenic polypeptides that may contribute to neoplastic cell proliferation. In the present study, we established a serum-free culture system for ameloblastoma cells and demonstrated that the addition of FGF-1 and FGF-2 enhanced cell growth in a dose-dependent manner. Immunoperoxidase staining of cultured cells demonstrated strong expression of FGF-1 and FGF-2. In tissue specimens, FGF-1 was localized in epithelial cell components of ameloblastomas, whereas FGF-2 was mainly found in the basement membranes with only moderate staining in epithelium. These data suggest that both FGF-1 and FGF-2 may contribute to the growth and development of ameloblastomas.

Adolescent↗

PubMed1994

Release of fibroblast growth factor-1 by human squamous cell carcinoma correlates with autocrine cell growth.

A squamous cell carcinoma cell line Nakata proliferated in serum-free culture and was not responsive to exogenous fibroblast growth factor-1 (FGF-1). Immunostaining revealed that Nakata cells expressed FGF-1 in their cytoplasms and nuclei. Two molecular mass species of FGF-1 (16 and 18 kDa) were identified in cell extracts by Western blot. These cells also expressed high-affinity FGF-1 binding sites (Kd = 360 pM, 28,000 sites/cell). The results of cross-linking with [125I]FGF-1 demonstrated the presence of two bands with molecular masses of 160 and 140 kDa. The addition of FGF-1 specific antisense oligonucleotides at 25 microM to Nakata cells resulted in an 82% inhibition in cell growth and suppressed FGF-1 expression. This effect was dose-dependent and specific, because sense oligonucleotides were ineffective in inhibiting cell growth. In addition, Nakata cell growth was suppressed by an anti-FGF-1 neutralizing antibody, which resulted in a 52% inhibition at 8 micrograms/ml. These results demonstrate that Nakata cells produce FGF-1, and indicate that this growth factor acts in an autocrine manner by interacting with FGF-1 binding sites on Nakata cells.

Base Sequence↗

PubMed1994

Invasive oral aspergillosis in immunocompromised patients with leukemia.

The clinicopathologic characteristics of invasive oral aspergillosis in 16 immunocompromised patients who developed this infection during antileukemic chemotherapy are described. The primary site of the infection was the marginal gingiva, there was severe spontaneous pain, and the patients developed spiking fever and granulocytopenia. Necrotic ulceration of the gingiva rapidly extended to the contiguous mucosa, muscle, and bone. Microscopically, the necrotic tissue contained thrombotic vascular infarcts and there were hyphae that showed frequent transverse septa and dichotomous branching. The invasive organisms were not responsive to amphotericin B in the absence of remission of the leukemia and restoration of the depressed host defenses. In 15 patients who showed improvement of hematologic status, oral aspergillosis was controlled by the combination of antifungal chemotherapy and debridement of necrotic tissues.

Adult↗

PubMed1994

Immunocytochemical localization of fibroblast growth factor-1 (FGF-1) and FGF-2 in oral squamous cell carcinoma (SCC).

The localization of fibroblast growth factor-1 (FGF-1) and FGF-2 in human oral squamous cell carcinoma (SCC) was examined by immunohistochemical techniques using anti-FGF-1 and anti-FGF-2 monoclonal antibodies. Immunofluorescence staining of two oral SCC cell lines revealed that growing cancer cells were intensely positive for both FGF-1 and FGF-2, but confluent cells showed a faint immunostaining. In addition, two molecular mass species of FGF-1 (16 and 18 kDa) and one of FGF-2 (18 kDa) were identified by Western blot in cell extracts derived from growing SCC cells, but not from confluent SCC cells. The growing cell extracts significantly stimulated the proliferation of human umbilical vein endothelial cells. Immunoperoxidase staining of 13 oral SCC cases showed that both well-differentiated and poorly-differentiated cancer cells were positive for FGF-1 and FGF-2 with high frequency and intensity as compared to normal oral epithelium. These results indicate that SCC cells express high levels of endogenous FGF-1 and FGF-2, and suggest that these growth factors may contribute to cancer cell growth.

Antibodies, Monoclonal↗

PubMed1993

Monoclonal antibodies against heparin-binding growth factor-1: neutralization of biological activity and recognition of specific amino acid sequence.

A panel of three monoclonal antibodies against heparin-binding growth factor-1 (HBGF-1) was obtained. These antibodies, Ab-47 alpha, Ab-15, Ab-29, were able to recognize HBGF-1 but not HBGF-2. One of the antibodies, Ab-47 alpha, was identified as a HBGF-1 neutralizing antibody on the basis of its ability to inhibit the binding of [125I]HBGF-1 to receptors on HepG-2 cells and the proliferation of fetal bovine heart endothelial cells induced by HBGF-1. Ab-15 reacted with truncated HBGF-1(Mr = 16,000), intact HBGF-1(Mr = 18,000) and mutant HBGF-1U which lacks a putative nuclear translocation sequence (amino acid residues 21 to 27 of HBGF-1). Ab-29 reacted with only truncated HBGF-1 and was thought to recognize the putative nuclear translocation sequence of HBGF-1. The three monoclonal antibodies did not inhibit the binding of [125I]HBGF-1 to heparin. These data indicate that each monoclonal antibody recognizes a distinct epitope of HBGF-1 and identifies them as useful reagents for evaluating functional domains and biological roles of HBGF-1.

Amino Acid Sequence↗

PubMed1991

Vascular endothelial cell growth factor (VEGF) produced by A-431 human epidermoid carcinoma cells and identification of VEGF membrane binding sites.

A distinct family of endothelial cell mitogens that are homologous to platelet-derived growth factor has recently been identified. Unlike other known endothelial cell mitogens, these vascular endothelial cell growth factors (VEGFs) are secreted and appear to act specifically on endothelial cells. We have purified VEGF 2083-fold to apparent homogeneity from protein-free culture medium conditioned by A-431 human epidermoid carcinoma cells. This A-431-derived VEGF was characterized as a homodimer composed of 22-kDa subunits with an N-terminal sequence that was similar to VEGFs produced by human HL-60 leukemic and U-937 histiocytic lymphoma cells. A-431 VEGF was used to identify specific and saturable binding sites for VEGF on human umbilical vein endothelial cells (HUVEC). By affinity cross-linking, VEGF-binding site complexes of 230, 170, and 125 kDa were detected on HUVEC. VEGF specifically induced the tyrosine phosphorylation of a 190-kDa polypeptide, which was similar in mass to the largest binding site detected by affinity cross-linking.

Amino Acid Sequence↗

PubMed1991

Hepatocyte growth factor/hepatopoietin A stimulates the growth of rat kidney proximal tubule epithelial cells (RPTE), rat nonparenchymal liver cells, human melanoma cells, mouse keratinocytes and stimulates anchorage-independent growth of SV-40 transformed RPTE.

Hepatocyte growth factor/hepatopoietin A is a mitogen for primary hepatocytes and may mediate regeneration after liver damage. To date, the activity of this novel factor has been restricted to hepatocytes. We now show that the factor is also a mitogen for a number of primary epithelial cells but is inactive with human foreskin fibroblasts, human endothelial cells and HEP3B cells. The factor also substitutes for HBGF-2 (basic FGF) in stimulating the anchorage-independent growth of SV-40 transformed rat kidney epithelial cells. Therefore, hepatocyte growth factor/hepatopoietin A appears to act on a variety of epithelial, but not mesenchymal, cells which respond to HBGFs.

Animals↗

PubMed1990

Bifunctional effects of transforming growth factor-beta (TGF-beta) on endothelial cell growth correlate with phenotypes of TGF-beta binding sites.

Transforming growth factor-beta (TGF-beta) is a bifunctional, dose-dependent regulator of endothelial cell proliferation induced in vitro by heparin-binding growth factor 1 (HBGF-1, acidic FGF). Here we have examined the relationship between endothelial cell growth and the expression of cell surface binding sites for TGF-beta and HBGF-1. Fetal bovine heart endothelial cell (FBHEC) growth was stimulated by low concentrations of TGF-beta and inhibited by high concentrations of TGF-beta while expressing two distinct classes of TGF-beta binding sites with binding constants of 24 pM (6300 sites/cell) and 900 pM (12,000 sites/cell). In contrast, human umbilical vein endothelial cells (HUVEC), whose growth was slightly promoted by TGF-beta, exhibited a single class of high-affinity TGF-beta binding sites (Kd = 45 pM, 4500 sites/cell). Affinity crosslinking using [125I]TGF-beta showed that FBHEC expressed two distinct low molecular weight TGF-beta binding sites (Mr 85,000 and 58,000), while HUVEC expressed a single type of low molecular weight TGF-beta binding site (Mr 85,000). As detected by binding of [125I]HBGF-1, preincubation of FBHEC with high concentrations of TGF-beta transmodulated the expression of high-affinity HBGF-1 receptors. In contrast, no transmodulation of HBGF-1 receptors occurred in FBHEC during preincubation with low concentrations of TGF-beta. Furthermore, preincubation of HUVEC with TGF-beta did not transmodulate the expression of HBGF-1 receptors. The data suggest that the ability of TGF-beta to stimulate or inhibit endothelial cell proliferation in a dose-dependent manner correlated with the expression of specific TGF-beta binding site subtypes and involved the transmodulation of HBGF-1 receptors.

Animals↗

PubMed1989

An alternative method for the isolation of NS-1 hybridomas using cholesterol auxotrophy of NS-1 mouse myeloma cells.

We have used the cholesterol auxotrophy of NS-1 mouse myeloma cells as the basis for selecting NS-1 hybridomas. The outgrowth of nascent NS-1 hybridomas in cholesterol-free serum-free medium was 3- to 9-fold more efficient than that in HAT medium and resulted in 3- to 13-times as many antigen-reactive hybridoma wells. This method of hybridoma selection can be applied with any sterol-dependent parent cell line. Hybridomas established under serum-free culture conditions were growth inhibited by fetal calf serum.

Aminopterin↗

PubMed1987

Monoclonal antibodies against human oral squamous cell carcinoma reacting with keratin proteins.

Two mouse monoclonal antibodies (MoAbs), B10 and 1H5, were generated by fusing mouse myeloma NS-1 cells with spleen cells from a BALB/c mouse immunized with Ueda-1 cells derived from human squamous cell carcinoma (SCC) of the floor of the mouth. Immunohistochemical analysis revealed that these MoAbs recognize the filamentous components of cytoplasm which were protein in nature. While the pattern of antigen distribution in various cell lines was not cell-type specific, reactivity of these antibodies with tissue sections was informative. MoAb 1H5 was preferentially reactive with well-differentiated squamous cell carcinoma, however, reaction with adenocarcinoma was observed infrequently. This antibody also preferentially reacted with the spinous layer of normal stratified squamous epithelium. MoAb B10, however, was reactive with nonepithelial tissues as well as with epithelial ones, and its level of binding bore no relationship to the grade of histologic malignancy. SDS-PAGE and Western blotting analysis, using cytokeratin extracts of Ueda-1 cells and human epidermis, demonstrated that MoAb B10 reacted with a wide range of keratin proteins of 65-67K, 58K, 56.5K, 56K, 52K, 50K, 48K, 45K, 40K, 38K, 36K, and 34K molecular weight (MW), while MoAb 1H5 reacted with keratin proteins of 65-67K, 58K, 56.5K, 56K, 52K, 48K, and 34K MW. These results suggest that MoAb 1H5 may recognize keratin subfamilies related to squamous differentiation, whereas MoAb B10 recognizes a wide range of keratin proteins, and may even react with other kinds of intermediate filament proteins (IFPs).

Antibodies, Monoclonal↗