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Biomedical subjects

M Tsujimoto

Publications and source records attributed to M Tsujimoto.

At least 199 records · Page 11Linked to original sources
PubMed1992

[A case of plasmacytoma of the ribs with intrathoracic tumors].

A 75-year-old male was admitted because of two tumors, one in the left middle lung field and one in the right upper lung field. Chest CT revealed intrathoracic tumors extending from destroyed ribs. Biopsy specimens of both tumors showed well-differentiated plasmacytoma. Retrospective investigation suggested that solitary plasmacytoma of bone (SPB) originating in the left fourth rib had developed into multiple myeloma (MM). Both tumors were treated with doses of 50 Gy irradiation and responded very well. Intrathoracic plasmacytomas have rarely been observed, so we have no established classification or therapy. According to reported cases, we classified intrathoracic plasmacytomas into 5 groups, and consider that treatment with doses of over 40 Gy irradiation was adequate for local control.

Aged↗
PubMed1991

Role of the C-terminus in the biological activity of human interleukin 5.

Alterations of the C-terminal amino acid sequence of recombinant human interleukin 5 (rhIL-5) caused significant changes in its biological activity. Removal of eight amino acids from the C-terminus of rhIL-5 by CNBr treatment led to a complete loss of biological activity as determined by the BCL1 cell IgM-inducing assay. Oxidation of Met residue located at C-terminus also resulted in a loss of activity. These results suggest that the C-terminal amino acids of rhIL-5 are crucial for its biological actions.

Animals↗
PubMed1991

Prognostic significance of argyrophilic nucleolar organizer staining in soft-tissue sarcomas.

The utility of argyrophilic stain for nucleolar organizer region (AgNOR) for estimating proliferative activity and prognosis of soft-tissue sarcomas (STS) was examined. Formalin-fixed and paraffin-embedded sections of 38 cases with STS were used; the reaction product of AgNOR stain was observed as dots mainly in the nucleoli. The mean number of AgNOR dots per nucleus of tumor cells was calculated in 200 cells (AgNOR count). The AgNOR count, ranging from 1.4 to 16.1 (mean, 7.5), showed a good correlation with cellularity (r = 0.483, p less than 0.003) and histologic grade (r = 0.626, p less than 0.00005), but less shown with mitotic counts (r = 0.350, p less than 0.04). The prognosis of cases with AgNOR low-count group (5-year survival rate was 74.6%) was much better than those in high count group (33.3%) (p less than 0.0005). The AgNOR count correlated well with reactivity of tumor cells for Ki-67 staining, which was available only in freshly prepared sections. These findings suggested that the AgNOR staining is a simple and useful method for estimating tumor-cell proliferation and prognosis of patients with STS.

Adolescent↗
PubMed1991

Solubilization of human placental tumor necrosis factor receptors as a complex with a guanine nucleotide-binding protein.

Human placental membranes exhibited high-affinity receptors for tumor necrosis factor (TNF) (Kd = 5.6 x 10(-10) M) with a density of 1.2-1.7 x 10(10) sites/mg protein. The receptors were solubilized from these membranes with 1% Nonidet P-40, and the solubilized receptor was adsorbed to Con A-Sepharose and wheat germ agglutinin agarose columns, indicating that the TNF receptor derived from human placenta contains carbohydrate chains recognized by these lectins. TNF binding activity was eluted from a column of Sephacryl S-300 as a single peak of Mr 300 kDa. The solubilized receptor was further purified by TNF-Sepharose prepared by coupling of TNF to tresyl-activated Sepharose 4B. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis of the purified sample resolved five major bands of Mr 90, 78, 41, 35, and 11 kDa, suggesting that these polypeptides constitute a multimeric complex with a molecular mass of 300 kDa, as observed in gel filtration study. Furthermore, the TNF-Sepharose-bound fraction demonstrated GTP gamma S binding and GTPase activity. Immunoblot analysis showed that the 41- and 35-kDa polypeptides were recognized by antisera against alpha subunits and beta subunit of GTP-binding proteins, respectively. These results suggest that the native TNF receptor couples to a guanine nucleotide-binding protein to form a large complex structure in human placental membranes.

Binding, Competitive↗
PubMed1991

The amino acid sequence of a glutamic acid-rich protein from bovine retina as deduced from the cDNA sequence.

cDNA clones encoding a glutamic acid-rich protein were isolated from a bovine retina cDNA expression library. The cDNA sequence contained an open reading frame of 1770 base pairs encoding a protein of 590 amino acids (64,509 Da) and untranslated regions of 60 and 490 base pairs at the 5' and 3' ends, respectively. The cDNA hybridized to a 2.4-kilobase retinal mRNA. The amino acid sequence derived from the cDNA sequence contains a glutamic acid-rich domain in which 68 of 109 amino acids are glutamic acid. In addition, this domain contains four repeats of a peptide of 11 amino acids and two repeats of a peptide of 26 amino acids. A polyclonal antibody raised against a decapeptide corresponding to the undecapeptide repeat sequence reacted with a protein in an extract of bovine rod outer segments, whose molecular mass, 65 kDa, corresponded to that of the above glutamic acid-rich protein. The retinal glutamic acid-rich protein showed homology with glutamic acid-rich proteins from bovine brain and the C-terminal region of mammalian neurofilaments.

Amino Acid Sequence↗
PubMed1991

Prostaglandins antagonize fibroblast proliferation stimulated by tumor necrosis factor.

Tumor necrosis factor (TNF) is known to be a mitogen for human diploid FS-4 fibroblasts. We have shown in an earlier study (Hori et al. (1989) J. Cell. Physiol. 141, 275-280) that indomethacin further enhances the cell proliferation stimulated by TNF. Since indomethacin inhibits the activity of cyclooxygenase, the role of prostaglandins in TNF-stimulated cell growth was examined. Cell growth stimulated by TNF and indomethacin was inhibited by exogenously added prostaglandins (PGE2, PGF2 alpha, and PGD2), among which PGE2 caused the greatest inhibition of cell growth. Treatment of FS-4 cells with 10 ng/ml TNF resulted in the release of prostaglandins (PGE2, 6-keto-PGF1 alpha, PGA2, PGD2, and PGF2 alpha) 2 to 4 fold over that of untreated cells. The amount of all these prostaglandins increased in a time-dependent manner over 6 h after treatment. In both TNF-treated and control cells, PGE2 was released as the predominant prostaglandin. Furthermore, when PGE2 production and DNA synthesis were determined in FS-4 cells treated with increasing doses of indomethacin, these two cellular responses were inversely affected by indomethacin. These data show that prostaglandins induced by TNF antagonize growth stimulatory action of TNF.

Arachidonic Acids↗
PubMed1991

Immunodetection of sialyl-Tn antigen in normal, hyperplastic and cancerous tissues of the uterine endometrium.

The expression of sialyl-Tn antigen (STn) in normal, hyperplastic and neoplastic tissues of the uterine endometrium was examined by immunoperoxidase staining of formalin-fixed, paraffin-embedded samples using the monoclonal antibody TKH-2, directed toward the STn structure (NeuAc 2-6GalNac 1-O-serine or threonine). STn was expressed in 13 of 18 normal postovulatory endometria with an increasing staining intensity and incidence in the late secretory phase. It was consistently absent in 10 proliferative endometria. None of 5 cystic, 4 adenomatous or 12 atypical hyperplasias expressed STn, but areas of severe cytological atypia in 3 atypical hyperplasias showed faint expression. STn expression was detected in 36 of 43 adenocarcinomas. Although the extent of staining varied from a few to most of the cancer cells, general staining was observed throughout the cytoplasm of cancer cells with increased staining of the luminal surface and frequent positive staining of intraluminal mucin. Thus, it is clear that STn is selectively expressed in cancer cells and shows restricted expression in normal and hyperplastic endometrial tissues. STn may be an early marker of malignant transformation and has potential for use as a diagnostic aid in the surgical pathology of the uterine endometrium.

Adenocarcinoma↗
PubMed1991

Carbohydrate structures of human interleukin 5 expressed in Chinese hamster ovary cells.

The asparagine-linked sugar chains of recombinant human interleukin 5 produced by Chinese hamster ovary cells were released quantitatively as oligosaccharides by hydrazinolysis. After N-acetylation followed by NaB3H4 reduction, each oligosaccharide was isolated by paper electrophoresis and serial lectin column chromatography. Study of their structures by sequential exoglycosidase digestion in combination with methylation analysis, revealed that they are bi-, tri-, and tetraantennary complex-type with fucosylated and non-fucosylated trimannosyl cores and high mannose type sugar chains. More than 80% of the sugar chains occur as biantennary complex-type sugar chains. Although acidic oligosaccharides amount to only 14% of the total oligosaccharides, their sialic acid residues occur exclusively as the Sia alpha 2----3Gal group. Removal of the sugar moiety from intact recombinant human interleukin 5 produced a 2.5-fold increase of its activity to induce IgM secretion.

Animals↗
PubMed1991

Histological factors contributing to favorable prognoses of soft tissue sarcomas in premenopausal patients.

The correlations of sex with various histologic factors in soft tissue sarcomas (STS) were studied in 142 adult patients over the age of 20 years. They included 63 with malignant fibrous histiocytomas, 20 with liposarcomas, 20 with synovial sarcomas, 11 with malignant Schwannomas and 28 with other forms of STS. These were divided into four groups, according to age (20-49 years and greater than or equal to 50 years) and sex. Survival rates in female patients were better than those in male patients, and the difference was significant between the 20-49 year groups (p less than 0.01). The relative frequencies in distribution of each histologic type were similar among male and female patients in both age groups. Among histological factors, mitotic counts showed a significant correlation (P less than 0.04) with sex, followed by cellularity. STS in female patients aged 20-49 years had lower mitotic counts than in patients in other groups, where it occurred with a higher frequency of low and intermediate grade tumors. The findings suggested estrogen, either directly to indirectly, to have a favorable effect on STS prognosis in premenopausal female patients.

Adult↗
PubMed1991

Immunohistochemical detection of high endothelial venules in extranodal B-cell lymphomas.

The hypothesis that extranodal malignant lymphomas, such as thyroid, stomach, rectum, ileum and uterus, eventuate from long-standing inflammation is essentially tested using a monoclonal antibody (HECA-452) to an endothelial-associated antigen selectively expressed by the high endothelim of post-capillary venules (HEVs) normally present in lymph nodes, tonsils and mucosa-associated lymphoid tissues. The presence of HEVs was examined on freshly prepared specimens from 16 cases of extranodal lymphoma of the B-cell type (eight thyroid, three stomach, two rectum, one ileum, one uterus, one tonsil). Control cases included reactive lymph nodes, nodal lymphoma of T-cell type, epithelial neoplasia, bone and soft tissue sarcomas, glioblastoma, thyroid affected by chronic lymphocytic thyroiditis (CLTH), thyrotoxicosis (Grave's disease) or nodular goiter, and salivary gland affected by Sjogren's syndrome (SS). HECA+ HEVs were present in reactive lymph nodes, nodal lymphoma, and all but one case of thyroid, all cases of stomach and all cases of rectal lymphoma, together with all CLTH and SS, both known to be autoimmune diseases. No thyroid, ileal or uterine lymphoma cases had any HECA positive venules. HECA+ venules were present in extranodal lymphomas, either adjoining the lymphoid follicles observed in several cases or in the diffusely proliferating tumor cells. Previous studies have shown that HEVs appeared in association with long-standing inflammation. The present study therefore, suggested that extranodal lymphomas of the thyroid, stomach and rectum evolve in long-standing inflammation, forming HEVs.

Antibodies, Monoclonal↗
PubMed1991

Involvement of prostaglandin-producing pathway in the cytotoxic action of tumor necrosis factor.

To elucidate the cytotoxic mechanism of tumor necrosis factor (TNF), we isolated TNF-resistant sublines of L929 cells. As compared with L929 cells, TNF-resistant cells retained similar number and affinity of TNF-binding sites, and showed a similar growth rate. TNF stimulated arachidonate release from L929 cells, while no stimulation was observed at all in TNF-resistant cells tested. The cytotoxic action of TNF on L929 cells was inhibited by indomethacin, suggesting that prostaglandin may be involved in the action. Therefore, TNF-stimulated prostaglandin production was examined in L929 and TNF-resistant sublines. The amount of PGE2 produced by L929 cells was increased more than 5-fold after the addition of TNF, whereas the amount of PGE2 did not change in the resistant sublines following addition of the factor. TNF-stimulated arachidonate release and PGE2 production were reversed by islet-activating protein (IAP)-treatment of L929 cells. These results suggest that arachidonate release and subsequent prostaglandin production are important for the cytotoxic action of TNF and that these processes are mediated by GTP-binding protein (G protein) that is coupled to the TNF-receptor.

Animals↗
PubMed1991

[Genetic, immunological and functional studies on lymphocytes with OKT4-epitope deficiency].

Although it is well-known that Leu3a-epitope on CD4 molecule functions as a receptor for human immunodeficiency virus (HIV), the function of OKT4-epitope is still obscure. In order to learn the significance of OKT4-epitope, we performed immunological and functional studies on lymphocytes obtained from individuals with incomplete/complete OKT-4 epitope deficiency. Their lymphocytes did not show any abnormality in their susceptibility to HIV infection, the internalization of CD4 molecules by TPA-treatment, the capability of producing IL-2 in vitro or the expression of IL-2R (alpha/beta-chain) by PHA-stimulation. By flow cytometric analysis it was demonstrated that quantity of OKT4-epitopes in the incomplete deficiency was approximately one-half less than that of normal individuals. Coupled with this fact and DNA analysis previously reported, individuals with incomplete/complete OKT4-epitope deficiency were considered to be heterozygote and homozygote, respectively. These results led us to the conclusion that OKT4-epitope deficiency was inherited as an autosomal codominant trait. Individuals with complete OKT4-epitope deficiency were found in 7 cases out of 1486 random samples (0.47%), from which individuals with incomplete OKT4-epitope deficiency were estimated to account for 12.8%.

Antibodies, Monoclonal↗
PubMed1991

[Burkitt's lymphoma with monoclonal pattern (IgG, kappa type) of cytoplasmic immunoglobulin--clinical report and review of Japanese literature].

A 52-year-old male was admitted to the hospital because of abdominal mass. Bone marrow examination revealed 26% blasts, which morphology was L3 in FAB criteria. Abdominal tumor was resected and histologic feature of the tumor was malignant lymphoma, small non-cleaved cell, Burkitt's. Lymphoma cells from the resected tumor were cultured and a cell line was established. Cytological studies of the original tumor cells and the cell line revealed that the lymphoma was negative both for EBNA and EBV DNA, and possessed t(8;14) (q24;q32) in chromosome analysis. Surface antigens were positive for HLA-DR, CD19 and CD20, but negative for CD10. The lymphoma also expressed a monoclonal pattern (IgG, kappa type) both of surface immunoglobulin and cytoplasmic immunoglobulin. Thus, the lymphoma was originated from mature B-lymphocyte. We analysed clinicopathological findings of 216 patients who were reported as Burkitt's lymphoma in Japan. Of 35 cases examined for cell EBNA, 7 (20%) were positive for EBNA. Of 86 cases tested for surface immunoglobulin of tumor cells, 67 expressed IgM alone and 10 IgG alone on tumor cells. Cytoplasmic immunoglobulin of tumor cells was positive in 61% of patients. Of 11 cases positive for cytoplasmic immunoglobulin, IgM was detected in 8 patients and IgG only in our patient.

Burkitt Lymphoma↗
PubMed1991

Atomic structure of a pyrimidine-dimer specific excision-repair enzyme from bacteriophage T4.

T4 endonuclease V is an enzyme responsible for the first step of a pyrimidine-dimer specific excision-repair process. The three-dimensional structure of this enzyme has been determined at 1.6A resolution by X-ray crystallography. The enzyme consists of one single compact domain classified into the all alpha structure. This single domain possesses two distinct catalytic activities, a pyrimidine-dimer glycosylase and an apurinic/apyrimidinic endonuclease. The backbone of the enzyme represents a unique folding scheme incompatible with close packing of alpha-helices. The refined structure suggests possible residues that participate in interactions with DNA.

Amino Acid Sequence↗
PubMed1990

Purification and characterization of kynurenine-pyruvate aminotransferase from rat kidney and brain.

Kynurenine-pyruvate aminotransferase (KPT), the enzyme responsible for the biosynthesis of the endogenous excitatory amino acid receptor antagonist kynurenic acid, was purified to homogeneity from rat kidney, as judged by polyacrylamide and sodium dodecyl sulfate electrophoresis. The protein appeared to consist of 2 identical subunits of approximately 48 kDa. Kinetic analysis showed Km values of 2.8 mM (kynurenine) and 3.8 mM (pyruvate), respectively. KPT was also partially purified from rat brain. Kidney and brain KPT were found to be identical when analyzed by a spectrum of biochemical, physico-chemical and, after production of anti-kidney KPT antibodies, immunological methods. Partially purified anti-KPT antiserum was used for first immunohistochemical studies, which revealed the presence of the enzyme in astrocyte-like cells throughout the brain. Less frequently, KPT was also found in discretely arranged neurons. The availability of pure KPT and specific anti-KPT antibodies can be expected to be of value for the further examination of the neurobiology of kynurenic acid.

Animals↗
PubMed1990

Identification of membrane anchoring site of human renal dipeptidase and construction and expression of a cDNA for its secretory form.

The chemical properties of human renal dipeptidase (hrDP) purified from the membrane fraction of kidney have been characterized. When treated with phosphatidylinositol-specific phospholipase C, hrDP was released from renal membrane fractions. After digestion with trypsin, carboxyl-terminal peptide was isolated employing anhydrotrypsin-agarose column chromatography and reversed-phase high performance liquid chromatography. The amino acid sequence of the peptide was identified at positions 363-369 in the primary structure deduced from the cDNA sequence (Adachi, H., Tawaragi, Y., Inuzuka, C., Kubota, I., Tsujimoto, M., Nishihara, T., And Nakazato, H. (1990) J. Biol. Chem. 265, 3992-3995). Further examination of the chemical composion of the peptide showed that it contained, respectively, 2, 1, 5, 1, and 1 mol of ethanolamine, glucosamine, mannose, inositol, and phosphate in addition to amino acids. These results suggest that the mature hrDP molecule lacks the carboxyl-terminal hydrophobic peptide extension predicted from the cDNA sequence and is anchored at Ser369 via glycosylphosphatidylinositol to the membrane. To characterize further the action of the enzyme, we have established expression systems for both secretory and membrane anchored forms of hrDP using COS-1 cells and found that both recombinant forms were as active as natural enzyme. Our expression system made it possible to prepare large amounts of soluble enzyme, and will contribute toward elucidation of the physiological roles of the enzyme.

Amino Acid Sequence↗