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Biomedical subjects

T Nakase

Publications and source records attributed to T Nakase.

At least 127 records · Page 7Linked to original sources
PubMed1994

Localization of osteopontin in the otoconial organs of adult rats.

Although it is known that mammalian otoconia consist of calcium bicarbonate and organic materials, none of the protein components have been identified in mammals at the molecular level, and the mechanisms of morphogenesis and calcification of the otoconia is still unclear. In the present study, we demonstrated the presence of osteopontin (OPN) in rat otoconia by using immunohistochemistry, and detected OPN mRNA in the sensory hair cells by a non-radioisotopic in situ hybridization technique. These results indicate that OPN is one of the protein components in rat otoconia and suggest that sensory hair cells are involved in the production of otoconia.

Animals↗
PubMed1994

Alterations in the expression of osteonectin, osteopontin and osteocalcin mRNAs during the development of skeletal tissues in vivo.

Heterogeneity in the expression of three members of non-collagenous matrix proteins in osteogenic and chondrogenic development in vivo were investigated by in situ hybridization. Sections of several skeletal tissues from mice at various stages of development were hybridized with digoxigenin-labeled complementary RNA probes encoding osteonectin (Osn), osteopontin (Osp) and osteocalcin (Osc). In calvariae and mandibulae, Osn messenger RNA (mRNA) was detected in cells in pre-osseous and osseous tissues before mineralization. Osp mRNA was found in cells attached to the mineralized bone matrix together with Osn mRNA followed by the expression Osc mRNA. In long bones, mRNAs for Osn, Osp and Osc were sequentially expressed with bone development from primary spongiosa to diaphyseal bone. In growth cartilage, Osn mRNA was observed in chondrocytes in non-mineralized cartilage, whereas Osp mRNA was detected in hypertrophic chondrocytes in mineralized cartilage matrix with a characteristic switch in expression. Osc mRNA was not detected in any chondrocytes. These results indicate that osteogenic differentiation in bone development in vivo is characterized by the sequential expression of these three genes, and suggest that these genes are expressed differentially and specifically, in association with extra-cellular matrix mineralization.

Animals↗
PubMed1994

Increased activated protein C-protein C inhibitor complex level in patients positive for lupus anticoagulant.

Activated protein C (APC)-protein C inhibitor (PCI) complex and APC-alpha 1antitrypsin (alpha 1AT) complex levels were measured in 29 patients positive for lupus anticoagulant (LA). LA was considered positive if two of the following three criteria were fulfilled: (1) prolongation of the activated partial thromboplastin time, (2) prolongation of the kaolin clotting time (KCT) and KCT mixing test, and (3) prolongation of the dilute Russell's viper venom time (DRVVT) and DRVVT/DRVVT with high lipid concentration. Plasma thrombin-antithrombin III (AT-III) complex and plasmin-alpha 2-antiplasmin inhibitor complex levels in patients positive for LA were increased slightly, but not significantly, and FDP-D-dimer and t-PA levels were not markedly increased. Plasma PAI-1 level in the LA-positive patients was significantly increased compared with normal volunteers. AT-III activity, protein C antigen, PCI antigen, and protein S antigen levels in the LA-positive patients were virtually normal, while protein C activity was slightly, but not significantly, decreased. APC-PCI complex level was increased in all LA-positive patients, and was not detectable in patients with systemic lupus erythematosus and normal volunteers. APC-alpha 1AT complex was increased slightly, in only two LA-positive patients; it was not detectable in the other patients or in the normal volunteers. These findings suggest that patients positive for LA are in a hypercoagulable state and that protein C activity in such patients is decreased, due to the activation of this protein.

Adult↗
PubMed1994

Increased vascular endothelial cell markers in patients with chronic renal failure on maintenance haemodialysis.

Plasma levels of the vascular endothelial cell markers, thrombomodulin (TM), plasminogen activator inhibitor-1 (PAI-1), tissue type plasminogen activator (t-PA), and von Willebrand factor (vWF) were measured in 55 patients on maintenance haemodialysis (HD). TM, PAI-1 and vWF antigen levels were significantly increased in patients before HD, but t-PA antigen was not Compared with levels before HD, t-PA and vWF antigens were significantly increased 1 h after HD and at the end of HD. TM antigen was significantly increased 1 h after HD, and plasma PAI-1 antigen was decreased at the end of HD. TM and vWF antigen levels were negatively correlated with the time (years) on HD. It is concluded that HD may cause endothelial cell damage and that the increases in plasma TM, PAI-1 and vWF levels before HD, and the decrease in the release of TM and vWF antigens from vascular endothelial cells, might be caused by vascular endothelial cell damage from long-term HD.

Adult↗
PubMed1994

Periosteal sunburst spiculation in osteosarcoma. A possible role for bone morphogenetic protein.

Periosteal sunburst spiculation is a peculiar radiographic feature of osteosarcoma, and it represents a reactive ossification resulting from the action of normal osteoblasts rather than tumor cells. Because bone morphogenetic protein is known to be a potent inducer of ectopic bone formation, the authors hypothesized that bone morphogenetic protein may be involved in the pathogenesis of such reactive bone formation in osteosarcoma. Chinese hamster ovary cells transfected with the bone morphogenetic protein-4 gene were injected into the femurs of athymic nude mice to form experimental bone tumors producing bone morphogenetic protein. Two weeks after intramedullary injection, new bone formation was observed radiographically and histologically within the extraosseous portions of the tumors. This showed a close resemblance to sunburst spiculation in human osteosarcomas. In contrast, the control nontransformed Chinese hamster ovary tumors showed no extraosseous bone formation. Because the induced bone was composed of multiple parallel spicules similar to those found in human bone morphogenetic protein-producing osteosarcomas, these findings suggest that periosteal sunburst spiculation may be the result of bone morphogenetic protein production by osteosarcoma cells.

Animals↗
PubMed1994

Enhanced tissue factor activity and plasminogen activator inhibitor-1 antigen in human umbilical vein endothelial cells incubated with lipoproteins.

The expression of tissue factor (TF) and plasminogen activator inhibitor (PAI)-1 was induced in cultured human umbilical vein cells (HUVEC) by very low density lipoprotein (VLDL). VLDL had a strong capacity for augmenting the expression of TF and PAI-1, while the capacity of LDL or high density lipoprotein (HDL) in this regard was very weak. VLDL and LDL also elevated TF activity in monocyte culture medium (VLDL, LDL) and the conditioned medium markedly elevated TF and PAI-1 production in HUVEC compared with directly added lipoproteins. These findings indicated that lipoproteins affect both monocyte-macrophages and endothelial cells, and that they cause a hypercoagulable-hypofibrinolytic state. It is thus possible that hyperlipidaemia could be a direct risk factor for thrombotic disease even if atherosclerotic lesions are not present.

Cells, Cultured↗
PubMed1994

Expression of genes encoding connective tissue proteins in androgen-dependent SC115 tumors after androgen removal.

BACKGROUND: Shionogi carcinoma 115 (SC115) is an androgen-dependent medullary carcinoma with a compact cell pattern. When SC115 tumors grow in androgen-depleted hosts, spindle-shaped and round cells with abundant cytoplasm develop. These cells originate from the SC115 cells (Kitamura et al., Cancer Res 1979;39:4717; Terada et al., Lab Invest 1987;57:186). EXPERIMENTAL DESIGN: We investigated whether these spindle-shaped and round cells expressed mRNAs of noncollagenous connective tissue proteins, which are expressed by normal spindle-shaped cells and normal chondrocytes in developing bones. The expression and localization of osteonectin (OSN), osteopontin (OSP), matrix Gla protein (MGP), and osteocalcin (OSC) were determined by Northern blotting and in situ hybridization. RESULTS: No mRNA signals of these proteins were detectable in SC115 medullary carcinoma cells growing in DS mice that had been castrated but received injections of testosterone propionate. However, when the injection of TP was stopped, spindle-shaped and round cells with abundant cytoplasm developed. The former expressed OSN and OSP signals, and the latter OSN, OSP, and MGP signals. CONCLUSIONS: Transcripts of OSN, OSP, and MGP were expressed by some SC115-derived cells during the differentiation events that occurred after androgen removal. These results provide molecular biologic evidence that a tumor of epithelial origin can progress along the connective tissue differentiation pathway.

Amino Acid Sequence↗
PubMed1993

Clonal analysis for developmental potential of chick periosteum-derived cells: agar gel culture system.

The developmental potential of periosteum-derived cells was clonally assessed with an agar gel culture system. Morphologically, two types of colonies were predominantly observed. By immunocytochemical observation with antibodies against aggrecan or bone Gla protein, one type of colony was judged to be chondrogenic, and the other osteogenic. By chronological observation, each type of colony did not convert to the other. Supplementation with transforming growth factor (TGF)-beta 1 shortened the time course of chondrogenesis and also increased colony forming efficiency of chondrogenic colonies. On the other hand, colony forming efficiency of osteogenic colonies decreased with TGF-beta 1 treatment, whereas the time course of osteogenesis remained unaffected. These observations suggest that there are both committed osteoprogenitor and chondroprogenitor cells present in the periosteal cell population, and TGF-beta 1 stimulates proliferation and differentiation of chondrogenic cell population by its targeted action.

Agar↗
PubMed1993

Non-universal decoding of the leucine codon CUG in several Candida species.

It has been reported that CUG, a universal leucine codon, is read as serine in an asporogenic yeast, Candida cylindracea. The distribution of this non-universal genetic code in various yeast species was studied using an in vitro translation assay system with a synthetic messenger RNA containing CUG codons in-frame. It was found that CUG is used as a serine codon in six out of the fourteen species examined, while it is used for leucine in the remaining eight. The tRNA species responsible for the translation of codon CUG as serine was detected in all the six species in which CUG is translated as serine. The grouping according to the CUG codon assignments in these yeast species shows a good correlation with physiological classification by the chain lengths of the isoprenoid moiety of ubiquinone and the cell-wall sugar contained in the yeasts. The six Candida species examined in which CUG is used as serine belong to one distinct group in Hemiascomycetes.

Amino Acid Sequence↗
PubMed1993

Hemostatic study before onset of disseminated intravascular coagulation.

Early diagnosis is necessary for the treatment of disseminated intravascular coagulation (DIC), but criteria for the stage preceding the diagnosis of DIC (pre-DIC) have not yet been established. To clarify hemostatic abnormalities that occur before the onset of DIC, we performed hemostatic studies in 117 patients within at least a week before the onset of DIC (pre-DIC), in 237 patients with DIC, and in 50 patients without DIC or pre-DIC (non-DIC). Levels of FDP, PT, and fibrinogen, and platelet counts were significantly abnormal after the onset of DIC, but not before. Thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC), and FDP-D-dimer levels were significantly higher before the onset of DIC compared to the non-DIC patients. Hemostatic abnormalities were observed within a week before the onset of DIC. Monitoring the plasma levels of TAT, PIC, and FDP-D-dimer might be useful for the diagnosis of a pre-DIC condition.

Antithrombin III↗
PubMed1993

Increased vascular endothelial cell markers in patients with disseminated intravascular coagulation.

We examined vascular endothelial cell markers, thrombomodulin (TM), plasminogen activator inhibitor-I (PAI-I), tissue plasminogen activator (t-PA), and von Willebrand factor, in 80 patients with disseminated intravascular coagulation (DIC). The levels of thrombin-antithrombin III complex (TAT), plasmin-alpha 2 plasmin inhibitor complex (PIC) and FDP-D-dimer were significantly increased both before and after the onset of DIC, but were not correlated with organ failure or prognosis. However, the PIC/TAT ratio was lower in patients with poor prognosis than in those with good prognosis, and it was also lower in those with organ failure than in those without. Plasma TM, PAI-I, and t-PA levels were increased in DIC patients with organ failure or poor outcome, but were not significantly increased before the onset of DIC. We consider that the prognosis of patients with DIC might be related to organ failure or endothelial cell damage and that plasma levels of TM, PAI-I, and t-PA might be useful in the detection of these disorders and in assessing prognosis. A hypofibrinolytic state might enhance organ failure in patients with DIC.

Antifibrinolytic Agents↗
PubMed1993

Elevated plasma levels of vascular endothelial cell markers in patients with hypercholesterolemia.

Hypercholesterolemia is associated with an increased incidence of vascular complications. To assess the actual degree of activation of coagulation systems and vascular disorders in hypercholesterolemia, plasma levels of vascular endothelial cell markers, such as thrombomodulin (TM), tissue-type plasminogen activator, plasminogen activator inhibitor-I (PAI-I), and von Willebrand factor, were measured in 51 patients with hypercholesterolemia. We also investigated the effects of Pravastatin, an inhibitor of 3-hydroxy-3-methylglutaryl coenzyme A reductase, on plasma lipid, lipoprotein a, and hemostatic markers. The mean plasma levels of thrombin-antithrombin III complex (TAT), fibrinopeptide A (FPA), TM, and PAI-I were significantly elevated in hypercholesterolemia. Of the hemostatic markers, only TM was significantly increased in patients with ischemic heart diseases (IHD). The mean concentration of total cholesterol and levels of TAT, FPA, PAI-I, and TM were significantly reduced after the Pravastatin treatment. The PIC/TAT ratio was significantly increased in non-IHD patients after treatment, this was not the case in IHD patients. These findings suggested the presence of a thrombogenic state and vascular endothelial cell disorders in hypercholesterolemia; such a state might well be related to hypofibrinolysis.

Adult↗
PubMed1993

The expanding realm of ballistosporous yeasts.

The recent progress in the systematics of ballistosporous yeasts is discussed. The extensive isolation studies carried out in the last decade resulted in a marked increase in the number of ballistosporous yeast species which now number nearly fifty. The increased number of species has expanded the complexity of taxonomic properties in the following ways: expansion of the range of mol% G+C of nuclear DNA to 39-68.5, thus overlapping that of all basidiomycetous yeasts; increased complexity of conidiogenesis with the finding of the genera Ballistosporomyces and Kockovaella. Based on partial sequencing of 18S ribosomal RNA (positions 1451-1618 in Saccharomyces cerevisiae), it is suggested that mode of conidiogenesis has little value for defining genera. Consequently, ballistosporous yeasts merely represent the "ballistosporous stage" of various taxa which cover the whole evolutionary spectrum of basidiomycetous yeasts. The importance of continuing isolation of ballistosporous yeasts is stressed, which together with molecular studies, will aid further progress in the systematics of basidiomycetous yeasts.

Base Composition↗
PubMed1993

Increased plasma level of interleukin-6 in disseminated intravascular coagulation.

Plasma interleukin-6 (IL-6) was higher in patients with disseminated intravascular coagulation (DIC) than in those without DIC. Levels of IL-1 beta and TNF alpha were also significantly higher in patients with DIC. Plasma IL-6 was highest in patients with underlying sepsis and was also high in those with advanced solid cancer. Levels were high in some patients with acute promyelocytic leukaemia and were significantly higher in patients with organ failure than in those without this complication. Plasma IL-6 was higher in DIC patients showing a poor response to therapy than in those with a good response. Incubation with IL-6 caused significant increases in tissue factor activity in mononuclear cells and release of plasminogen activator-1 antigen from human umbilical vein endothelial cells. As increases in IL-6 might give rise to hypercoagulable and hypofibrinolytic states, this may be a cause of DIC and be related to prognosis and organ failure.

Disseminated Intravascular Coagulation↗
PubMed1993

Stimulation of tissue type plasminogen activator by leukaemic cell homogenates.

In patients with disseminated intravascular coagulation (DIC), hyperfibrinolysis was observed in patients with leukaemia, but hypofibrinolysis was seen in those with sepsis. Although the plasma tissue plasminogen activator (t-PA) level was higher in patients with DIC than in those without DIC, there was no significant difference in t-PA level between the patients with leukaemia and sepsis. Hyperfibrinolysis might not be caused by t-PA derived from leukaemic cells, although the PA antigen level in leukaemic cell homogenates was significantly higher in patients with DIC than in those without DIC. The activation of t-PA by leukaemic cell homogenates in the absence of bromocyan fibrinogen fragments suggested that leukaemic cell homogenates had t-PA stimulator activity. The t-PA stimulator activity was high in both acute myeloblastic leukaemia (AML) and acute lymphoblastic leukaemia (ALL), especially in DIC, but this activity was not detected in chronic myelocytic leukaemia (CML) or normal cells. Since fibrinogen and soluble fibrin monomer complex levels in leukaemic cells were also high in patients with DIC, fibrinogen degradation products might be the major t-PA stimulator in leukaemic cells. This might be one of the causes of hyperfibrinolysis in leukaemia.

Biomarkers, Tumor↗
PubMed1993

Streptomyces subtilisin inhibitor-like proteins are distributed widely in streptomycetes.

Streptomyces subtilisin inhibitor-like proteins were found to be distributed widely in streptomycetes by using the combination of the convenient, newly developed plate assay system and an established liquid culture assay. Almost all the strains formerly categorized as Streptoverticillium species produced proteins that exhibited inhibitory activity against both subtilisin BPN' and trypsin. N-terminal regions of three purified proteins showed high structural similarity to those of other previously reported SIL inhibitors.

Amino Acid Sequence↗
PubMed1993

Transforming growth factor-beta 1 stimulates chondrogenesis and inhibits osteogenesis in high density culture of periosteum-derived cells.

Chick periosteum-derived mesenchymal cells have been reported to exhibit both osteogenic and chondrogenic potentials in high cell density culture conditions. Using this culture system, the effects of transforming growth factor-beta (TGF beta) on proliferation and differentiation of periosteal mesenchymal cells were studied. Supplementation with TGF beta 1 at doses of 0.3-1.0 ng/ml shortened the time course of chondrogenesis and increased the amount of cartilage formed in the lower part of the culture. On the other hand, the amount of bone formed in the upper part of the culture decreased with TGF beta treatment, whereas the time course of osteogenesis remained unaffected.

Animals↗