Biomedical subjects

T Ohmori

Publications and source records attributed to T Ohmori.

At least 199 records · Page 11Linked to original sources

PubMed1989

Uncommon type of meningiomas with conspicuous plasmo-lymphocytic infiltration. An immunohistochemical and histochemical study.

Two cases of meningioma revealing conspicuous plasmo-lymphocytic tissue and hyalinized fibrous tissue components are reported. Histopathological examination of the plasmo-lymphocytic infiltration was performed. Both lesions showed polyclonality of plasma cells as revealed by positive reactions for IgG and paraimmunoglobulin kappa- and lambda-light chains, and amyloid infiltration into the fibrous stroma and blood vessel walls. The histochemical and immunohistochemical characteristics of the lesion in relation to its etiology are briefly discussed.

Adult↗

PubMed1989

Isolation of galactosaminoglycan moiety (CO-N) from protein-bound polysaccharide of Cordyceps ophioglossoides and its effects against murine tumors.

A galactosaminoglycan moiety was obtained from an antitumor polysaccharide fraction (SN-C) isolated from Cordyceps ophioglossoides culture. SN-C was subjected to sonication, then a protein-bound galactosaminoglycan (CO-N) was isolated specifically by precipitation with 10% ammonium hydroxide. When given intraperitoneally to mice, CO-N inhibited the proliferation of sarcoma 180 cells inoculated into the peritoneal cavity and exhibited a marked life-prolonging effect against ascitic tumors such as Ehrlich carcinoma and IMC carcinoma. CO-N also showed an inhibitory effect against solid Ehrlich carcinoma when given intratumorally and significantly inhibited the growth of a syngeneic solid tumor (MM46 mammary carcinoma) upon intravenous administration at a low dose. CO-N showed a cytocidal effect against cultured cells of IMC and P388D1 in vitro. Flow cytometric analysis demonstrated that fluorescein isothiocyanate-CO-N binds to the surface of Ehrlich cells.

Animals↗

PubMed1989

The correlation between molecular weight and antitumor activity of galactosaminoglycan (CO-N) from Cordyceps ophioglossoides.

A galactosaminoglycan (CO-N) obtained by ultrasonication from a protein-bound polysaccharide SN-C, which was isolated from Cordyceps ophioglossoides culture, has a direct cytotoxicity against tumor cells (Ohmori et al., Chem. Pharm. Bull., 37, 1019 (1989). High performance liquid chromatographic analysis revealed that CO-N shows a broad molecular weight distribution with an average molecular weight of 33000. A potent antitumor activity of CO-N was observed in the higher-molecular-weight fraction on gel filtration, and the low-molecular-weight fraction below 6600 showed a weak activity. However, the depolymerized CO-N (ca. 5500) obtained by further ultrasonication of the original CO-N still retained the antitumor activity of CO-N against Ehrlich ascitic carcinoma or MM46 solid mammary carcinoma.

Animals↗

PubMed1989

[Anomalous case of the left common carotid artery arising from the brachiocephalic trunk].

We found an anomalous branch of the aortic arch during the students' dissection practice at Fukuoka Dental College in 1988. The results are as follows; This case was found in a 92-year-old female cadaver (cause of death: cardiac dissufficiency), whose brachiocephalic trunk arose from the aortic arch forming a striking trunk with the left common carotid artery. The diameter of this trunk was 17.2 mm at its origin and the longitudinal length was 11.0 mm. This case corresponded to Typus B of Adachi's classification, while to Type C of De Garis's.

Aged↗

PubMed1989

Immunohistochemical study of a case of malignant müllerian mixed tumor in comparison with the activity of normal uterine tissue.

A case of malignant Müllerian mixed tumor of the uterus, exhibiting a histology of heterologous osteosarcomatous differentiation, is presented. Special emphasis is placed on the characteristic immunohistochemical reactivity of the tumor tissue in comparison with that of normal uterine tissue in the proliferative phase. Keratin, cytokeratin, epithelial membrane antigen (EMA), carcinoembryonic antigen (CEA), and human chorionic gonadotropin (HCG) were found only in the carcinomatous element. However, neuron specific enolase (NSE), S-100 protein (S 100) and vimentin were identified in almost all tumor tissue elements. Desmin and actin were not stained in any elements. Myoglobin was only detected weakly in the squamous carcinomatous element. Undifferentiated cell element, composed of small, round, spindle, or polygonal cells showed positive reactions to NSE and S 100, but not to any other antibodies. As compared to the reactivities of the normal proliferative endometrium, the glandular epithelial cells were positive with NSE, S 100, vimentin and CEA, but the stromal cells were only positive with vimentin. Such a multitudinous and concomitant expression of antigenicity to the different tumor elements indicates a close relationship to its mesodermal Müllerian origin, and NSE, S 100 and vimentin might be most adequate indicators of these types of tumors.

Adenocarcinoma↗

PubMed1989

[The dental anthropological study on the erupted mesiodens in the Paiwan tribe of Formosan aborigines].

Mesiodens is one supernumerary tooth which appears in upper intra-central incisors. This tooth was originally described by Bolk (1917) who proposed the term 'mesiodens'. We investigated the incidence of mesiodens for the Paiwan tribe of Formosan aborigines (9 tribes) living in the mountain area of Taiwan. We have been continued to research on these tribes as viewed from dental anthropology. The materials used in this study were plaster casts of 152 males and 238 females (dental age: IIIA or over). The samples of the Paiwan tribe were selected from the dental casts obtained at Taitung and Pingtung (Machia and Wutai) in southern Taiwan. The results were as follows: 1. The occurrence of the erupted mesiodens in the upper incisal region was five cases (3.3%) in males, but was none in females. This tendency of incidence was much the same as that of Japanese. 2. The mesiodens was of rudimentary form: four cases (80%) showed conical-shaped type and the rest case was the sort of incisor. 3. In the incidence of the erupted mesiodens, the Paiwan tribe showed significantly higher than Japanese.

Anthropology↗

PubMed1988

Phosphorylation by cyclic AMP-dependent protein kinase of a human platelet Mr 22,000 GTP-binding protein (smg p21) having the same putative effector domain as the ras gene products.

We have purified to near homogeneity a Mr 22,000 GTP-binding protein from human platelet membranes and identified it as the smg-21 gene product (smg p21), having the same putative effector domain as the ras gene products, which we have purified to near homogeneity from bovine brain membranes and characterized. This purified human platelet smg p21 was phosphorylated by cyclic AMP-dependent protein kinase. About one mol of phosphate was maximally incorporated into one mol of the protein. Only serine residue was phosphorylated. Both the guanosine 5'-(3-O-thio)-triphosphate (GTP gamma S)-bound and GDP-bound forms were phosphorylated with the same reaction velocity. The phosphorylation of smg p21 affected neither its GTP gamma S-binding nor GTPase activity. Human platelet smg p21 was not phosphorylated by protein kinase C. A Mr 24,000 GTP-binding protein partially purified from human platelet membranes was not phosphorylated by cyclic AMP-dependent protein kinase or protein kinase C.

Animals↗

PubMed1988

Identification of a platelet Mr 22,000 GTP-binding protein as the novel smg-21 gene product having the same putative effector domain as the ras gene products.

We have recently purified a Mr 22,000 GTP-binding protein (G protein) to near homogeneity from human platelet membranes and characterized it (Ohmori, T., Kikuchi, A., Yamamoto, K., Kim, S. and Takai, Y. (1989) J. Biol. Chem. in press). This platelet G protein was present most abundantly among several G proteins in platelets and showed a Mr of about 22,000 as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. This platelet G protein showed kinetic and physical properties very similar to those of the novel smg-21 gene product, having the same putative effector domain as the ras gene products, which we have recently purified to near homogeneity from bovine brain membranes and characterized (Kawata, M., Matsui, Y., Kondo, J., Hishida, T., Teranishi, Y. and Takai, Y. (1988) J. Biol. Chem. in press). Moreover, the peptide map of the platelet G protein was identical with that of the smg-21 gene product and the partial amino acid sequence of the platelet G protein was identical with that of the smg-21 gene product. These results indicate that this human platelet G protein is the smg-21 gene product.

Amino Acid Sequence↗

PubMed1988

Serotonin as a major serum factor inducing the phospholipase C-mediated hydrolysis of phosphoinositides in normal rat kidney cells.

Calf serum induced the phospholipase C-mediated hydrolysis of phosphoinositides in normal rat kidney (NRK) cells transformed by a temperature-sensitive Kirsten murine sarcoma virus (tsK-NRK cells). Various growth factors known to induce the phospholipase C reactions in other cell types, such as platelet-derived growth factor, fibroblast growth factor, epidermal growth factor, thrombin, vasopressin, bombesin, cholecystokinin, and prostaglandin F2 alpha, did not induce phospholipase C reactions in the transformed NRK cells. Furthermore, noradrenaline, histamine, dopamine, angiotensin II, carbachol, and tumor growth factor-beta did not induce phospholipase C reactions. However, serotonin did induce phospholipase C reactions. The amount of serotonin contained in the calf serum was sufficient to support 50% of the activity promoted by the serum itself, and calf serum-induced phospholipase C reactions were inhibited to 10-20% of the original level by ketanserin and methysergide, known to be antagonists for the serotonin receptors. Dialysis almost completely removed serotonin from calf serum and reduced the serum-induced phospholipase C reactions. Moreover, the phospholipase C reactions induced by calf serum and serotonin were inhibited by pretreatment of the cells with pertussis toxin or 12-O-tetradecanoylphorbol-13-acetate. These results indicate that serotonin is one of the major serum factors inducing phospholipase C-mediated hydrolysis of phosphoinositides in transformed NRK cells. Serotonin induced phospholipase C reactions not only in tsK-NRK cells but also in nontransformed NRK cells. However, serotonin did not induce these reactions in Swiss 3T3 cells or NIH 3T3 cells.

Adenosine Diphosphate Ribose↗

PubMed1988

Different sensitivity to phorbol esters and pertussis toxin of bombesin- and platelet-derived growth factor-induced, phospholipase C-mediated hydrolysis of phosphoinositides in NIH/3T3 cells.

Incubation of the serum-deprived cultures of NIH/3T3 cells with bombesin or platelet-derived growth factor (PDGF) induced the phospholipase C-mediated hydrolysis of phosphoinositides. Protein kinase C-activating 12-O-tetradecanoylphorbol 13-acetate (TPA) and pertussis toxin inhibited the bombesin-induced phospholipase C reactions. AlF4-, a direct activator of GTP-binding proteins (G proteins), also induced the phospholipase C reactions and TPA inhibited the AlF4- -induced reactions. These results suggest that a pertussis toxin-sensitive G protein is involved in the coupling of the bombesin receptor to the phospholipase C and that the coupling of the G protein to the phospholipase C is inhibited by protein kinase C. In contrast, neither TPA nor pertussis toxin inhibited the PDGF-induced phospholipase C reactions, indicating that a pertussis toxin-sensitive G protein is not involved in the coupling of the PDGF receptor to the phospholipase C and that this coupling is insensitive to protein kinase C. These results suggest that the regulatory mechanism of the PDGF receptor for the phospholipase C activation is different from that of the bombesin receptor.

Adenosine Diphosphate Ribose↗

PubMed1988

Binding of ras p21 to bands 4.2 and 6 of human erythrocyte membranes.

The direct binding protein(s) of ras p21 was (were) investigated in inside-out vesicles of human erythrocyte ghosts using the pure v-Kirsten (Ki)-ras p21 synthesized in E. coli. The bound ras p21 was detected immunochemically using an anti-v-Ki-ras p21 monoclonal antibody, ras p21 bound to vesicles. Prior digestion of the vesicles with trypsin reduced this binding significantly. When ras p21 was laid over vesicle proteins immobilized on a nitrocellulose sheet by transfer from the gel of SDS-polyacrylamide gel electrophoresis, ras p21 bound to bands 4.2 and 6. ras p21 binding to these proteins was reduced by prior incubation of ras p21 with the purified band 4.2 or 6 protein. These results indicate that v-Ki-ras p21 can bind directly to bands 4.2 and 6 of human erythrocyte membranes as far as tested in an in vitro cell-free system.

Blood Proteins↗

PubMed1988

Self-organizing system obtaining communication ability. Primitive model for language generation.

As one of the synthetic approaches to brain functions, the possibility is discussed that two intellectual robots could make "words" for themselves and come to communicate with each other. Associatron, a model for associative memory with a neural network structure, is used as the memory in the brain, and information from the outer world is accumulated in it. Concepts regarding objects and attributes are extracted from the stored information, where the Associatron properties are utilized. The robots give specific names to the concepts and interchange them with each other. When the robots have the same experience at the same time, they modify their own words according to what the other robot says. As they repeat common experiences, the differences between the words become smaller and smaller, and finally the robots agree on a word for each object. At this stage, the robots can exchange information with their words and each can act accordingly on the word from the other. This study shows that the self-organizing system with the above function can be constructed as a neural network model.

Artificial Intelligence↗

PubMed1988