3d-resonance-photoemission study of CeB6 and PrB6.
Explore the source record for details and available documents.
Biomedical subjects
Publications and source records attributed to S Imada.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
Explore the source record for details and available documents.
PURPOSE: In several previous reports, it has been suggested that the androgen system is related to bladder carcinogenesis. In this study, to understand the mechanism underlying this relationship, we administered a LH-RH agonist depot (Leuprolide depot), a pure-antiandrogen (flutamide) or a 5 alpha-reductase inhibitor (finasteride) to the mice in the promotion state of bladder carcinogenesis by N-butul-N-(4-hydroxybutyl) nitrosamine (BBN). MATERIALS AND METHODS: 177 C3H/He male mice were divided into 7 groups. All mice were treated with 0.05% BBN for 10 weeks and were maintained over the subsequent 12 weeks with the following treatments. Group 1 was a control group; in group 2, castration was performed at the 11th week; in group 3, finasteride was administered starting the 11th week; in group 4, a LH-RH agonist depot was administered starting the 11th week; in group 5, flutamide was administered starting the 11th week; in group 6, both finasteride and a LH-RH agonist depot were administered simultaneously starting the 11th week; and in group 7, both flutamide and a LH-RH agonist depot were administered simultaneously starting the 11th week. RESULTS AND CONCLUSIONS: (1) We confirmed that castration significantly suppressed bladder carcinogenesis. (2) Finasteride or flutamide administration as monotherapy had no effect on the results; however, the dosages of these drugs may have been too low, so we are planning a study with higher doses. (3) Conversely, the LH-RH agonist depot significantly promoted bladder carcinogenesis, we believe that the high levels of testosterone immediately after the administration were responsible for this promotion. (4) Simultaneous administration of flutamide suppressed this LH-RH induced promotion of carcinogenesis.
It is known that diffusible trophic factors play an important role in both the normal and cancerous growth regulatory processes of hormone-responsive cells such as are found in the prostate and mammary glands. Consequently, it is important to identify whether the production of such growth factors is affected by administration of therapeutic agents. We examined the effect of bestrabucil, a benzoate of an estradiol-chlorambucil conjugate, on the production of growth factor(s) by Shionogi carcinoma 115 (SC-115) cells, an androgen-responsive cultured cancer cell line. We then investigated whether the inhibitory effect found was specific to bestrabucil, or if it was also produced by a mixture of the 2 compounds, estradiol and chlorambucil. Bioassay employing BALB/3T3 cells demonstrated the presence of two kinds of growth factor in the conditioned medium obtained by culturing SC-115 cells in medium containing 10(-8) M testosterone; these factors could be separated by heparin-sepharose column chromatography using 0.5 M NaCl and 1.1 M NaCl. When the SC-115 cells were cultured in medium containing bestrabucil, at a concentration of 10(-5) M, no growth factor activity was detected in the fraction eluted from the heparin-sepharose column by 1.1 M NaCl. At bestrabucil concentrations of 10(-5)-10(-7) M, concentration-dependent inhibition of growth factor production by SC-115 cells could be demonstrated by 3H-thymidine uptake assay. However, this inhibitory effect could not be demonstrated using only a mixture of estradiol and chlorambucil.(ABSTRACT TRUNCATED AT 250 WORDS)
A 41-year-old man incidentally found to have a right renal and left large lung tumor in the course of screening for liver dysfunction was admitted to our hospital. Needle biopsy of each tumors revealed histologically renal cell carcinoma and pulmonary blastoma. The renal tumor grew rapidly and soon he died of DIC. Autopsy was performed and the final diagnosis was adult Wilms' tumor and its metastasis to the lung. Histological findings of each large tumors showed different histologic pattern. The renal tumor revealed diffuse nephroblastic subtype and the lung tumor showed epitherial type. This is a rare case of Wilms' tumor in terms of its adult onset and different histologic pattern between the primary tumor and its metastatic lesion.
A 81-year-old man was admitted to the hospital because he complained of hoarseness. Chest radiography showed a mass in the right upper mediastinum. An operation was done to remove the mass and make a conclusive diagnosis. Histologically, the tumor tissue consisted of spindle-shaped fibroblast-like cells and round histiocyte-like cells with bizarre giant cells. Part of the tissue had a storiform pattern. These findings led a diagnosis of malignant fibrous histiocytoma (MFH) of the "usual type". MFH is known to occur frequently in the soft tissues of extremities, trunk, and retroperitoneum, but it is seldom detected in the mediastinum. We report here a rare case of primary MFH in the mediastinum.
Four types of cells, RT4-AC (stem cell type), RT4-B and RT4-E (neuronal cell types), and RT4-D (glial cell type) were previously isolated from an ethylnitrosourea (ENU) induced rat peripheral neurotumor RT4. In a phenomenon termed cell-type conversion, RT4-AC spontaneously and permanently gives rise to the three other cell types in culture. In the RT4 system the expression of glial fibrillary acidic protein (GFAP) and S100 beta protein genes segregates in a cell-type specific manner. To further characterize the RT4 family, the expression of four myelin-forming glial genes--P0 glycoprotein, suppressed cAMP inducible POU (SCIP), 2',3'-cyclic nucleotide 3'-phosphodiesterase (CNP), and myelin basic protein (MBP)--has been studied in the RT4 cell lines. In addition to these genes, the expression of the low-affinity nerve growth factor (LNGF) receptor (expressed in immature Schwann cells) has been examined. We have found the following results. 1) The stem cell type RT4-AC and the glial cell type RT4-D express mRNA transcripts of P0, SCIP, and CNP (the larger form, 2.8 kb), and the amount of mRNA of these genes was increased by forskolin. 2) RT4-AC and RT4-D also express a low level of MBP mRNA upon forskolin treatment. 3) The neuronal cell types RT4-B and RT4-E do not express any of these myelin-forming glial genes with or without forskolin treatment. 4) The LNGF receptor mRNA is expressed in RT4-AC and RT4-D and at a lower level in RT4-B; its expression is stimulated by forskolin.
We reported that a cell surface thrombin receptor, thrombomodulin (TM), was regulated by cyclic AMP in fibroblasts and in parietal endoderm-like cells derived from F9 embryonal carcinoma cells. In this paper, the genetic basis for augmentation of TM expression by cyclic AMP was studied in F9 and BALB/3T3 cells. Transient expression assays were performed with plasmid constructs containing various 5' flanking sequences of the TM gene and a reporter gene, chloramphenicol acetyltransferase (CAT). Two regulatory DNA regions, the proximal (-411 to -50) and the distal (-1026 to -850), were located. Interplay of the two regions was suggested using a heterologous thymidine kinase promoter in differentiated F9 cells. Both proximal and distal regions contributed to cyclic AMP-dependent augmentation of CAT expression in differentiated F9 cells, whereas only the proximal region was functional in BALB/3T3 cells. The two cell types responded differently also to a protein synthesis inhibitor, cycloheximide, with respect to TM message accumulation. In BALB/3T3 cells TM message accumulation was refractory to the inhibitor in contrast to that of differentiated F9 cells, which was only partially so. We propose that there are at least two separate genomic DNA regions that regulate cyclic AMP-dependent TM gene expression and that their functions are cell type dependent.
A case of intraductal papilloma occurring in the anterior lingual salivary gland (Blandin-Nuhn's gland) of a 58-year-old woman is presented. This location has not been reported previously. The results of histologic and immunohistochemical studies point to an epithelial origin of excretory salivary gland ducts and also demonstrate the secretory potential of the tumor cells.
From August, 1989 to July, 1991, we carried out transabdominal ultrasonography for screening of abdominal and pelvic disease in regular health check-up at Mito Saiseikai Hospital. Of 5,706 screened examinees were ultrasonographically suspected of bladder tumor and subsequently received a cystoscopic examination. Cystoscopy confirmed bladder tumors in 9 of the 11 patients. Eight of the 9 cases showed no urological symptoms, while the remaining 1 case showed microscopic hematuria objectively. All of the 9 cases revealed a transitional cell carcinoma of low grade and low stage. The smallest tumor detected by ultrasonography was 5 mm in diameter. Transabdominal ultrasonography proved useful for diagnosis of the bladder tumor at its early stage in the mass screening. Therefore, it is recommended to perform lower abdominal ultrasonography as a routine examination of the multiphasic health testing and services.
A patient with chronic T-cell leukemia characterized by a suppressor phenotype is reported. A 71-year-old woman presented with symptoms and signs of hypercalcemia. Peripheral blood specimen showed abnormal lymphoid cells with an oval to cleaved nucleus, rather condensed chromatin, occasional prominent nucleolus, and basophilic cytoplasms with vacuoles which seems to be a T-cell counterpart of B-cell chronic lymphocytic leukemia with mixed cell types. The phenotype of these cells was CD4-, CD8+, CD5+, CD6+ with poor expression of CD3, CD7, and CD25. Southern blot analysis of T-cell receptor beta-chain gene revealed one allele rearranged band. The serum antibodies were positive against human T-cell leukemia virus, type I-associated antigens, but monoclonal integration of proviral DNA was not detected in the leukemic cells suggesting that she was just a carrier of this virus. Interestingly, serum PTH-related peptide (PRP) was elevated. The combination therapy with vincristine and prednisolone for leukemia decreased not only the number of leukemic cells but also the serum PRP levels. The clinical course was aggressive. She only responded transiently to treatments, and died of renal failure due to uncontrollable hypercalcemia six weeks after admission.
Fetomodulin (FM) was previously shown to be a surface marker protein of parietal endoderm by in vitro differentiation of F9 embryonal carcinoma cells and by immunohistochemistry of in vivo embryos. BALB/3T3 and sarcoma S180 cells of the mouse were also shown to possess a protein which was indistinguishable from FM by immunological and structural criteria. We now show by protein and DNA sequencing and by functional assays that FM is identical to thrombomodulin, an anticoagulant endothelial thrombin receptor. Partial amino acid sequences of FM from S180 cells suggested homology between FM and thrombomodulin. An FM cDNA fragment was obtained by screening an expression library, which was constructed with restricted BALB/3T3 cDNA, with polyclonal anti-FM antibody. Several longer cDNA clones were than isolated using this fragment as a probe. They elucidated a 3369-bp partial sequence which encompassed 93% of the coding sequence. The remaining structure was determined from a genomic DNA clone. The deduced FM structure proved to be identical to that of thrombomodulin of mouse lung. Affinity-purified FM of BALB/3T3 and differentiated F9 cells was as active as thrombomodulin of the lung in binding thrombin and also as an anticoagulant. Structural and functional identity of the two proteins was thus confirmed. During embryonic development, FM immunoreactivity is localized not only in vasculatures but also at sites of cell-to-cell contact, including lung bud and neural epithelium, which were not expected a priori to possess this endothelial surface protein. FM may be a multifunctional protein with unique roles in embryonic development.
Fetomodulin is a surface marker protein of differentiated F9 embryonal carcinoma cells. Gene cloning has recently identified it as thrombomodulin which binds thrombin and proteolytically activates protein C. Activity assays and RNA blotting were adopted to analyze F9 cell differentiation with specific reference to another well-characterized marker, tissue plasminogen activator. Retinoic acid induced primitive endoderm differentiation of F9 cells and simultaneously activated tissue plasminogen activator synthesis. This differentiation, however, did not result in fetomodulin expression. When primitive endoderm cells were exposed to 1 mM dibutyryl cyclic AMP, the tissue plasminogen activator level rose further within 6 hr. In contrast, the cofactor activity of fetomodulin stayed below a detectable level for as long as 15 hr and then increased with time. Expression of the two marker proteins appeared to be regulated differently.
The presence of membrane-associated, extracellular protein kinase (ecto-protein kinase) and its substrate proteins was examined with serum-free cultures of Swiss 3T3 fibroblast. When cells were incubated with [gamma-32]ATP for 10 min at 37 degrees C, four proteins with apparent molecular weights between 150 and 220 kDa were prominently phosphorylated. These proteins were also radiolabeled by lactoperoxidase catalyzed iodination and were sensitive to mild tryptic digestion, suggesting that they localized on the cell surface or in the extracellular matrix. Phosphorylation of extracellular proteins with [gamma-32P]ATP in intact cell culture is consistent with the existence of ecto-protein kinase. Anti-fibronectin antibody immunoprecipitated one of the phosphoproteins which comigrated with a monomer and a dimer form of fibronectin under reducing and nonreducing conditions of electrophoresis, respectively. The protein had affinity for gelatin as demonstrated by retention with gelatin-conjugated agarose. This protein substrate of ecto-protein kinase was thus concluded to be fibronectin. The sites of phosphorylation by ecto-protein kinase were compared with those of intracellularly phosphorylated fibronectin by the analysis of radiolabeled amino acids and peptides. Ecto-protein kinase phosphorylated fibronectin at serine and threonine residues which were distinct from the sites of intracellular fibronectin phosphorylation.
A novel cell surface marker of fetal development was identified in both in vivo and in vitro systems of the mouse using monoclonal antibodies against a glycoprotein of an apparent size of 133,000 Da. Two independent clones of hybridomas were isolated by fusing murine myeloma cells, NS-1, with spleen cells of a rat which was immunized with murine 3T3 fibroblast. The analysis of molecular size and tryptic peptides of the immunoprecipitate indicated that fibroblast and putative parietal endoderm cells, which were derived by induced differentiation of F9 embryonal carcinoma cells with retinoic acid and cyclic AMP, expressed apparently the same protein. Undifferentiated F9 cells and F9 cells which were treated with retinoic acid or cyclic AMP alone had little or no immunoprecipitable proteins. Analogously, parietal endoderm of in vivo embryos tested positive for this protein but visceral endoderm and embryonic ectoderm did not. The amount of this surface protein was increased in fibroblast and differentiated F9 cells by elevation of intracellular cyclic AMP concentrations. These results are consonant with a hypothesis that this surface protein plays a role in fetal development via a quantitative modulation by cyclic AMP.
A gene mapped to the long arm of human chromosome 11 was previously characterized to code for a cell-surface glycoprotein of an apparent molecular mass of 200 kDa in fibroblasts. We now report that this surface protein is expressed in an increased amount when human fibroblasts or human X Chinese-hamster hybrid cells containing human chromosome 11 are treated with 1 mM dibutyryl cyclic AMP. A detailed analysis of this phenomenon of induction was performed using a long-established, stable cell line of human X Chinese-hamster hybrid cells, J1 clone, which contained human chromosome 11 and expressed the 200 kDa glycoprotein of human origin. It was shown that the 200 kDa protein of J1 cells was inducible with 1 mM dibutyryl cyclic AMP, 10 mM unmodified cyclic AMP, 0.2 mM 8-para-chlorophenylthio cyclic AMP or 1 nM cholera toxin. Induction was potentiated by the addition of a phosphodiesterase inhibitor, Ro 20-1724. These results are consistent with the finding in human fibroblast, confirming that human fibroblasts express a 200 kDa glycoprotein on their surface which is regulated by intracellular concentrations of cyclic AMP. The regulation may be at the level of transcription since the addition of actinomycin D prevented the induction.