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Biomedical subjects

H Murakami

Publications and source records attributed to H Murakami.

At least 451 records · Page 25Linked to original sources
PubMed1993

Secretory cell immunoscreening assay--a highly sensitive screening method for secretory cells.

We have developed a rapid and sensitive screening method to detect the secretory product from transformed secretory cells. Polyclonal antibodies against the target secretory protein are first adsorbed onto a nitrocellulose membrane and are then called solid-phase antibodies. Then this membrane is placed on top of target protein-secreting adherent animal cell colonies. After trapping the secreted protein on the membrane, the protein is detected using the highly sensitive enhanced chemiluminescence detection system. Thus, this method is named the secretory cell immunoscreening assay (SCISA). We have screened recombinant BHK-21 cells, which secrete human interleukin-6 (hIL-6) for highly productive clones. With the SCISA method, it is possible to detect less than 100 pg of hIL-6 secreted by a single colony. We are also able to select highly productive colonies rapidly and easily from a large sample population of transformed cell colonies.

Animals↗
PubMed1993

Identification of hybrid-type carbohydrate chains on the light chain of human monoclonal antibody specific to lung adenocarcinoma.

The carbohydrate chains on the light chains of human monoclonal antibody HB4C5 reactive to human lung adenocarcinoma tissue have been characterized. The HB4C5 antibody consists of two kinds of light chains (30 kDa and 32 kDa). Each chain has different carbohydrates of varying molecular masses linked to the variable regions. The 30 kDa light chain has been confirmed to be the active species for antibody binding. The carbohydrates on the light chains were characterized by lectin blot analysis combined with glycosidase treatment. A carbohydrate chain linked to the active 30 kDa light-chain species, and one of a few carbohydrate phenotypes on the 32 kDa light-chain species is characterized as "hybrid type". A sialylated complex-type carbohydrate could also bind to the 32 kDa light-chain species. Nucleotide sequence analysis revealed that one potential N-glycosylation site is located in the complementarity determining region 1 of the light chain, although no such site was found in the variable region of the heavy chain.

Adenocarcinoma↗
PubMed1993

Cloning and expression of flatfish (Paralichthys olivaceus) interferon cDNA.

Fish interferon (IFN) cDNA was first cloned from the cDNA library of immortalized flatfish leukocytes. The clone contains an open reading frame that encodes a 138 amino acid polypeptide including a glycosylation site and a signal peptide containing 30 amino acids. BHK-21 cells transfected with the INF-expression plasmid produced active recombinant IFN (about 16 kDa) which was then purified by WGA agarose affinity chromatography. This recombinant IFN inhibited infection of fish cells with the Hirame (flatfish) rhabdovirus.

Amino Acid Sequence↗
PubMed1993

Signal sequence region of mitochondrial precursor proteins binds to mitochondrial import receptor.

An integral mitochondrial membrane protein (p32) of yeast has previously been molecularly cloned and sequenced and suggested to function as a mitochondrial import receptor. However, this protein has also been proposed to function as phosphate translocator [Guérin, B., Bukusoglu, C., Rakotomanana, F. & Wohlrab, H. (1990) J. Biol. Chem. 265, 19736-19741; Phelps, A., Schobert, C.T. & Wohlrab, H. (1991) Biochemistry 30, 248-252]. Here we have purified p32 after expression of its gene in Escherichia coli and assayed its ability to bind to various preproteins containing signal sequences for protein translocation into mitochondria, chloroplasts, or the endoplasmic reticulum. Our data suggest that p32 contains a binding site specific for the signal sequence region of mitochondrial preproteins. These data are consistent with the previous assignment of p32 as an import receptor and are discussed with regard to the apparently conflicting assignment of this protein as phosphate translocator.

Base Sequence↗
PubMed1993

Transgenic mouse model for synergistic effects of nuclear oncogenes and growth factors in tumorigenesis: interaction of c-myc and transforming growth factor alpha in hepatic oncogenesis.

Double transgenic mice bearing fusion genes consisting of mouse albumin enhancer/promoter-mouse c-myc complementary DNA and mouse metallothionein 1 promoter-human transforming growth factor alpha complementary DNA were generated to investigate the interaction of these genes in hepatic oncogenesis and to provide a general paradigm for characterizing the interaction of nuclear oncogenes and growth factors in tumorigenesis. Coexpression of c-myc and transforming growth factor alpha as transgenes in the mouse liver resulted in a tremendous acceleration of neoplastic development in this organ as compared to expression of either of these transgenes alone. The two distinct cellular reactions that occurred in the liver of the double transgenic mice prior to the appearance of liver tumors were dysplastic and apoptotic changes in the existing hepatocytes followed by emergence of multiple focal lesions composed of both hyperplastic and dysplastic cell populations. These observations suggest that the interaction of c-myc and transforming growth factor alpha, and possibly other combinations of nuclear oncogenes and growth factors, during development of hepatic neoplasia contributes to the selection and expansion of the preneoplastic cell populations which consequently increases the probability of malignant conversion.

Animals↗
PubMed1993

Ultrastructure of plasma cells in a patient with J chain disease.

Ultrastructural analysis of plasma cells was performed in a 74-year-old female patient with J chain disease. By electron microscopy, various characteristic findings were observed: lobulated nuclei, multinuclei, single sac loop-like structures, flocculent filament-like substances, nuclear inclusion bodies, cytoplasmic inclusion bodies, and multilamellar bodies. Our prior studies pointed out a poor prognosis in myeloma patients with these findings.

Aged↗
PubMed1993

Ultrastructure of neutrophilic phagosome of autologous platelet in vivo in specific granule deficiency.

The ultrastructure of neutrophilic phagosomes containing autologous platelets in vivo from a woman with specific granule deficiency is described. This phagosome formation was observed only when she had developed pneumonia due to Staphylococcus aureus. Therefore, the phenomenon might be induced by severe bacterial infection under an abnormal neutrophilic condition accompanied by specific granule deficiency.

Adult↗
PubMed1993

Primary plasmacytoma of generalized lymph nodes: a long survivor.

Extramedullary plasmacytomas are occasionally seen in the course of multiple myeloma; however, primary plasmacytomas are unusual. Most of the primary plasmacytomas arise in the upper respiratory system, but a plasmacytoma of the lymph nodes is very rare. A case of a 56-year-old female with primary plasmacytoma in the lower mandibular, cervical, axillary, and para-aortic lymph nodes accompanied by IgA Kappa paraproteinemia is described. After ten courses of combination chemotherapy with cyclophosphamide and prednisolone, she obtained complete response. However, 6 years later, she had a relapse of plasmacytoma in the generalized lymph nodes. She received ten treatments of melphalan-prednisolone and again obtained complete response. She has remained well without chemotherapy or recurrent signs for 9 years. It is considered that conventional chemotherapy can be useful for primary plasmacytoma of generalized lymph nodes.

Female↗
PubMed1993

Characterization of the mineralization process in cultures of rabbit growth plate chondrocytes.

The present study was undertaken to investigate the mineralization process in chondrocyte cultures. Chondrocytes were isolated from the growth plate of ribs of 4-week-old rabbits. The nature and properties of mineral crystals precipitated in chondrocyte cultures were compared with those of crystals formed in the hypertrophic zone and bone of rabbit rib growth plates in vivo. The chondrocytes were maintained at high density on type II collagen-coated dishes in Eagle's medium, alpha-modification, with 10% fetal bovine serum and 50 micrograms/ml of ascorbic acid. These cells differentiated into hypertrophic cells 10 days after seeding and produced alkaline phosphatase and 1,25-dihydroxyvitamin D3 receptors on Days 30-70 at levels as high as those in the lower hypertrophic zone in vivo. Mineralization was initiated between Days 20 and 30 and advanced progressively throughout the culture period. However, mineralization was suppressed by the addition of parathyroid hormone (2 x 10(-8) M) or by the presence of fibroblasts. Examination by electron microscopy and Fourier transform infrared (FTIR) spectroscopy verified that mineralized nodules formed in vitro were composed of small apatite crystals. Importantly, FTIR spectral features of the apatite crystals (e.g., the prominent PO4 bands at 1125 and 1032 cm-1) were similar to those of cartilage apatites formed in vivo and differed markedly from those of carbonated bone apatites. These results suggest that growth plate chondrocytes cultured on collagen-coated dishes are an appropriate model for studies on cartilage mineralization.

Alkaline Phosphatase↗
PubMed1993

Hemangiopericytomatous meningioma metastasized to the liver: report of a case and review of the literature.

A 54-year-old male was admitted to our hospital for treatment of a liver tumor which was pointed out by screening ultrasonography. Computed tomography revealed a tumor in the right lobe of the liver measuring 7 cm in diameter. Angiography revealed a hypervascular tumor. A hepatocellular carcinoma or hypervascular metastatic tumor was suspected. A right hepatic lobectomy was performed. The patient had previously undergone operations for a hemangiopericytomatous meningioma in the occipital fossa in 1972 and 1977. The histological findings of the liver tumor were identical to those for hemangiopericytomatous meningioma, so the etiology was considered to be liver metastasis from the previous meningioma. Nineteen cases of extracranial metastasis of hemangiopericytomatous meningioma have been reported in the literature, but hepatic resections of this metastasizing tumor have been very rare.

Brain Neoplasms↗
PubMed1993

Purification and characterization of interferon-like antiviral protein derived from flatfish (Paralichthys olivaceus) lymphocytes immortalized by oncogenes.

Flatfish leukocytes were transfected with the expression plasmids of the v-myc, c-myc, c-fos, v-myb and c-Ha-ras oncogenes. Only cotransfection of c-Ha-ras with c-myc or c-fos resulted in complete immortalization of the cells. Interferon-like anti-viral protein was found in the cultured medium of the immortalized lymphocytes. The protein was purified by DEAE-Toyopearl 650 M ion exchange chromatography and WGA agarose affinity chromatography. The protein was a glycoprotein of about 16 kDa. The antiviral activity of the protein was trypsin-sensitive and was fairly stable at pH values from 4 to 8. The protein retained about 60% of the activity even at 60 degrees C and showed a broad antiviral activity for various fish cells and viruses.

Animals↗
PubMed1993

Immortalization of human T lymphocytes by oncogenes.

Immortalized human T cell lines were established by cotransfecting c-Ha-ras and c-myc oncogenes to lymph node lymphocytes. The cell lines kept growing for 3 months after establishment without a decrease in growth rate. The cells did not require interleukin-2 (IL-2) for their growth, but addition of IL-2 stimulated the growth of these cells. Flow cytometric analysis revealed that these cells were T cells expressing CD4 or CD8 antigens. A CD4 positive (CD4+) cell line produced IL-6, indicating that the cell line belongs to helper T cells. The CD8 positive (CD8+) cell line possessed cytotoxicity to tumor cells, indicating that the cell line were killer T cells. Both cell lines were able to proliferate in serum-free medium indefinitely.

Cell Division↗
PubMed1993

Change of paraprotein from IgG lambda to lambda chain in myeloma.

We describe a unique case of IgG lambda myeloma in which a plasma cell leukemia developed and the paraprotein changed from IgG lambda to lambda chain, the latter inducing fatal renal failure. In addition, J-chain was detected in the cytoplasm of the plasma cell leukemia cells.

Female↗
PubMed1993

Spurious macrocytosis associated with non-Hodgkin's lymphoma: report of two cases.

We report two rare cases of spurious macrocytosis (SM) associated with non-Hodgkin's lymphoma caused by cold agglutinin. SM was reversed, accompanied by the regression of lymphoma in case 1 but not in case 2, where the lymphoma was refractory to the chemotherapy. It is strongly suggested that lymphoma cells were related to the production of cold agglutinin and the cause of SM.

Adult↗
PubMed1993

MCNU in the treatment of essential thrombocythemia--a pilot study.

The efficacy of a single dose of MCNU 150 mg was evaluated in nine symptomatic patients with essential thrombocythemia (ET). As the platelet counts increased during the following 4 weeks, an extra dose of 100 mg of MCNU was administered to three patients. All patients had thrombotic or hemorrhagic complications. Seven patients responded. The mean platelet count decreased to below 1.0 x 10(12)/l within 5 weeks; it reached its lowest level (0.35 x 10(12)/l) at 6 weeks and became stable at less than 1.0 x 10(12)/l without further therapy for 12 weeks in all patients. Thrombotic and hemorrhagic complications ameliorated within 4 weeks in all patients. Our study indicates that MCNU acts as a platelet-reducing agent in patients with ET.

Adult↗
PubMed1993

The detection of a breast cancer antigen on MCF-7 cells reactive with the TCR (alpha) of a specific killer T cell line.

We established several immortalized human T cell lines by cotransfecting primary lymphocytes derived from breast cancer patients with human c-myc and human c-Ha-ras oncogenes. A CD8 positive (CD8+) killer T cell line, FT-8, exhibited in vitro specific cytotoxicity to a human breast cancer cell line, MCF-7. The FT-8 cells suppressed the growth of MCF-7 cells transplanted to athymic mice. The cytotoxic reaction was caused via T cell antigen receptor (TCR) on MCF-7 cells, because monoclonal antibodies against the TCR inhibited the cytotoxicity of FT-8 cells. The TCR (alpha) cDNA of FT-8 was cloned by using a PCR amplification technique and expressed by a cell-free in vitro translation system. The TCR (alpha) protein recognized a target antigen of 32 KDa on MCF-7 cells.

Animals↗