Biomedical subjects

T Nakase

Publications and source records attributed to T Nakase.

At least 19 recordsLinked to original sources

PubMed1995

Ballistosporous yeasts found on the surface of plant materials collected in New Zealand. 1. Six new species in the genus Sporobolomyces.

Six new species of ballistosporous yeast, the genus Sporobolomyces, were isolated from dead leaves and fruit of plants collected in New Zealand; Sp. novazealandicus, Sp. dimmenae, Sp. coprosmicola, Sp. coprosmae, Sp. dracophyllus, and Sp. taupoensis. These species differ from any hitherto known species of Sporobolomyces based on chemotaxonomic characteristics.

Base Composition↗

PubMed1995

Use of monoclonal antibody to detect bone morphogenetic protein-4 (BMP-4).

A monoclonal antibody that reacts with murine and human bone morphogenetic protein-4 (BMP-4) has been developed using recombinant BMP-4 as an immunogen. The antibody that bound most tightly to recombinant murine (rm)BMP-4 was selected, subcloned, and characterized. The specificity of the antibody was confirmed using Western blot analysis and enzyme-linked immunosorbent assay (ELISA). The antibody reacts with murine and human BMP-4 in both the reduced and nonreduced condition; however, this antibody shows cross-reactivity with neither human BMP-2 nor TGF-beta 1. Thus, the produced antibody could recognize the disulfide-linked dimeric structure of bioactive BMP-4, regardless of the species. Immunocytochemical study using this antibody successfully shows the cytosolic localization of BMP-4 in osteoinductive cells; i.e., BFO and Saos-2 in which the level of mRNA for BMP-4 was proved to be constitutively high by Northern blot analysis. In addition, the antibody could demonstrate the presence of BMP-4 in developmental bone formation in the alveolar bone of rat embryo by immunohistochemistry. The antibody could be used for a more sensitive approach for quantitative analysis of BMP-4.

Animals↗

PubMed1995

Phylogenetic analysis of the ballistosporous anamorphic genera Udeniomyces and Bullera, and related basidiomycetous yeasts, based on 18S rDNA sequence.

The small subunit nuclear ribosomal DNA (18S rDNA) sequence was determined for twelve species of basidiomycetous anamorphic yeasts, i.e. three species of Udeniomyces, seven species of Bullera, Cryptococcus albidus and Phaffia rhodozyma. For phylogentic analysis, these sequences were aligned with published sequences for 36 other fungal species. Molecular phylogenetic analysis of maximum likelihood and parsimony showed that the 44 species of basidiomycetes analysed were divided into three major lineages. The ballistosporous yeast genera Udeniomyces and Bullera were clearly separated. On the phylogenetic tree, Udeniomyces megalosporus, U. puniceus and U. piricola showed a very close relationship with one another, and composed a lineage with Mrakia frigida, P. rhodozyma and Cystofilobasidium capitatum at high bootstrap confidence level. On the other hand, eight species of Bullera made lineages with selected species of Tremella (Tremellaceae), Filobasidium and Filobasidiella (Filobasidiaceae), Cryptococcus albidus and Trichosporon cutaneum. The molecular phylogeny deduced from the 18S rDNA sequence showed a possibility of heterogeneity among the species of Bullera at the generic level.

Base Sequence↗

PubMed1995

Regulation of proliferation and osteochondrogenic differentiation of periosteum-derived cells by transforming growth factor-beta and basic fibroblast growth factor.

We studied the effects of transforming growth factor-beta and basic fibroblast growth factor on the regulation of proliferation and osteochondrogenic differentiation of periosteum-derived cells, which have the potential to differentiate into bone and hypertrophic cartilage in vitro. Histological observation revealed that transforming growth factor-beta stimulated chondrogenesis of periosteum-derived cells while basic fibroblast growth factor stimulated proliferation of fibroblast-like cells and inhibited osteochondrogenic differentiation. Immunohistochemical studies revealed that basic fibroblast growth factor inhibited the expression of osteocalcin. Transforming growth factor-beta enhanced uronic acid content but decreased DNA content, alkaline phosphatase activity, and calcium content. In contrast, basic fibroblast growth factor enhanced DNA content but decreased alkaline phosphatase activity, calcium content, and uronic acid content. In addition, transforming growth factor-beta shortened the time-course of gene expression of type-X collagen whereas basic fibroblast growth factor inhibited the gene expression. These results indicate that transforming growth factor-beta stimulates osteochondrogenic differentiation of periosteum-derived cells but inhibits proliferation. They also indicate that basic fibroblast growth factor stimulates proliferation of periosteum-derived cells but inhibits osteochondrogenic differentiation.

Alkaline Phosphatase↗

PubMed1995

Decreased plasma tissue factor pathway inhibitor levels in patients with thrombotic thrombocytopenic purpura.

We measured plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with thrombotic thrombocytopenic purpura (TTP) and disseminated intravascular coagulation (DIC) to examine the relationship between TFPI and vascular endothelial cell injury. TF antigen was detected in the plasma of healthy volunteers, and the levels were significantly increased in the patients with DIC, but decreased slightly in those with TTP. Plasma TFPI levels were significantly decreased in patients with TTP compared with those in healthy volunteers. The concentration of plasma thrombomodulin (TM) antigen was significantly higher in those with TTP than in normal volunteers. One month after treatment, TTP patients showed a significant decrease in plasma TM levels, and a significant increase in plasma TFPI levels, but plasma levels of TF antigen were not significantly increased. As plasma TFPI/TF ratio was significantly increased after treatment, the hypercoagulable state was therefore improved after treatment. There was no significant difference in plasma TF and TFPI levels between those who achieved complete remission (CR) and those who died. However, plasma TM levels were significantly higher in those who died than in those who achieved CR. Plasma TFPI levels might reflect injury of vascular endothelial cells as do plasma TM levels, and decreased plasma TFPI/TF ratio and vascular endothelial cell injuries might play causative roles in TTP.

Adolescent↗

PubMed1994

Elevated plasma tissue factor antigen level in patients with disseminated intravascular coagulation.

The plasma tissue factor (TF) antigen level was measured in patients with disseminated intravascular coagulation (DIC). The plasma TF antigen was detected in normal volunteers, and it was significantly higher in DIC patients than in non-DIC patients. However, in some patients with DIC, the plasma TF antigen level was within the normal range. The plasma TF antigen level in patients with DIC significantly decreased after therapy, but it was not correlated with organ failure or outcome. The plasma TF antigen level in patients with DIC was not correlated with other hemostatic markers. The plasma TF antigen level tended to be higher in DIC patients with nonlymphoid leukemia than in those with lymphoid tumor. TF might be implicated in the occurrence and progression of DIC.

Antigens↗

PubMed1994

Transient and localized expression of bone morphogenetic protein 4 messenger RNA during fracture healing.

Temporal and spatial distribution of a gene encoding murine bone morphogenetic protein 4 (mBMP-4) during fracture repair were investigated in mice by RT-PCR and in situ hybridization. For in situ hybridization, fractured ribs and surrounding tissues were decalcified and hybridized with a mBMP-4-specific complementary RNA probe labeled with digoxigenin-11 UTP. mBMP-4 messenger RNA (mRNA) was not detected in ribs without fracture, whereas it was detected only in the early phase of fracture from 12 to 72 h after the onset of fracture before new cartilage or bone formation. The mBMP-4 mRNAs were present in cells distributed in three distinct regions, namely, the proliferating periosteum, the medullary cavity, and the muscles near the fracture site. These BMP-4-positive cells did not express bone gla protein mRNA, which is a marker of the mature osteogenic cell. RT-PCR also showed a transient increase in the level of BMP-4 mRNA in the early phase of fracture repair. The findings provide us with some new information. (1) The BMP-4 gene is produced by less differentiated osteoprogenitor cells, not by differentiated osteoblasts. (2) The BMP-4 gene is enhanced by the impact of fracture and localized in callus-forming tissue before callus formation. Together with the activities of BMP-4, as was previously described, our results suggest that newly produced BMP-4 gene product is one of the local contributing factors in callus formation in the early phase of fracture healing.

Animals↗

PubMed1994

Bone morphogenetic protein 2 stimulates osteogenesis but does not affect chondrogenesis in osteochondrogenic differentiation of periosteum-derived cells.

The effects of recombinant human bone morphogenetic protein 2 (rhBMP-2) on osteochondrogenesis were examined in high-density cultures of periosteum-derived cells, which have the potential to differentiate into bone and hypertrophic cartilage in vitro. Proliferation of these cells was inhibited by treatment with rhBMP-2. The time course for alkaline phosphatase (ALP) expression was shortened and the mineralization of the culture was increased by supplementation with rhBMP-2. These stimulatory effects of rhBMP-2 were observed at doses of 10-100 ng/m. Bone Gla protein (BGP) was immunocytochemically detectable earlier in the culture treated with rhBMP-2, and the BGP-positive layer of the rhBMP-2-treated cultures was thicker than that of the control cultures. On the other hand, there was no difference in uronic acid content or the time course of alpha 1(II) collagen mRNA expression between the rhBMP-2-treated and the control cultures. These results indicate that rhBMP-2 shortens the time course of osteogenesis and increases the amount of bone formation, whereas chondrogenesis remains unaffected.

Alkaline Phosphatase↗

PubMed1994

Expression of mRNA of murine bone-related proteins in ectopic bone induced by murine bone morphogenetic protein-4.

To determine whether a system of ectopic bone formation induced by osteosarcoma-derived bone-inducing substance (bone morphogenetic protein-4) can be used as a model of developing bone at the molecular level, we studied the expression of bone-related protein mRNAs in the process of ectopic bone formation using non-radioisotopic in situ hybridization. Osteonectin mRNA was detected in fibroblast-like cells, which are similar to periosteal cells from the early to middle stages of bone development. The proportion of osteonectin mRNA-expressing cells was greater than that of osteopontin mRNA-expressing cells in hypertrophic chondrocytes and osteoblast-like cells. In contrast, osteopontin mRNA was localized in a limited population of hypertrophic chondrocytes, a single layer of osteoblast-like cells adjacent to the bone trabeculae in the middle stage of bone formation, and in a limited subset of osteocytes in the late stage. A strong osteocalcin mRNA signal was detected in osteoblast-like cells from the middle to late stages and in a limited subset of osteocytes in the late stage of bone development. Since the sequential gene expression pattern of bone-related proteins in the present system is comparable to that in embryonic osteogenesis, this system may be useful as a model for studying gene expression in osteogenesis.

Animals↗

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↗