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Biomedical subjects

T Nakase

Publications and source records attributed to T Nakase.

At least 109 records · Page 6Linked to original sources

Purification and properties of D-aspartate oxidase from Cryptococcus humicolus UJ1.

D-Aspartate oxidase (EC 1.4.3.1), which is highly specific to D-aspartate, was inducibly produced by a yeast strain which was isolated from soil and identified as Cryptococcus humicolus UJ1. The enzyme was purified to homogeneity as indicated on SDS-polyacrylamide gel electrophoresis. The molecular mass of the monomer subunit was determined to be 40 kDa. The native enzyme was suggested to be a homotetramer by its behavior on gel filtration. The enzyme was shown to be a flavoprotein by its absorption spectral properties, and the flavin was found to be tightly, but not covalently, bound FAD. The purified preparation had a specific activity of 76.1 mumol/min per mg protein with D-aspartate as substrate. Optimum pH was 7.5 and optimum temperature was around 35 degrees C. D-Glutamate was a very poor substrate for the enzyme. N-Methyl-D-aspartate was better than D-glutamate as substrate but markedly poorer than D-aspartate. Malonate was the most effective competitive inhibitor of the compounds tested. The N-terminal amino-acid sequence of the enzyme showed a significant homology with those of D-aspartate oxidases from beef kidney and Octopus vulgaris and those of D-amino-acid oxidases from various sources.

Amino Acid Oxidoreductases↗

Increased plasma-soluble fibrin monomer levels in patients with disseminated intravascular coagulation.

Plasma-soluble fibrin monomer (SFM) level in patients with disseminated intravascular coagulation (DIC) was significantly higher than the level in patients with pre-DIC or in non-DIC patients, and the level in patients with pre-DIC was significantly higher than that in non-DIC patients. There was no significant difference in plasma SFM levels among various diseases underlying DIC. Plasma SFM level in patients with good outcome was significantly decreased after treatment for DIC. The sensitivity of fibrin degradation products and platelet number was high for DIC, but not for pre-DIC. The sensitivity of thrombin-antithrombin III complex, plasmin-plasmin inhibitor complex, and SFM was high for both DIC and pre-DIC. The specificity of these markers was also high. Receiver operating characteristic analysis suggests that plasma SFM level could be the most useful marker for the diagnosis of both DIC and pre-DIC.

Amino Acid Sequence↗

Plasma tissue factor and tissue factor pathway inhibitor levels in patients with disseminated intravascular coagulation.

We measured the plasma levels of tissue factor (TF) and tissue factor pathway inhibitor (TFPI) in patients with disseminated intravascular coagulation (DIC) to examine the relationship between TFPI and vascular endothelial cell injury. Plasma TF (273 +/- 90 pg/ml) and TFPI (252 +/- 125 ng/ml) levels were significantly increased in patients with DIC compared with non-DIC patients. Plasma TF antigen level was significantly increased in pre-DIC patients (285 +/- 85 pg/ml), while the plasma TFPI level (152 +/- 54 ng/ml) was not markedly increased in such a state. The plasma TF/TFPI ratio was high in the pre-DIC patients (2.10 +/- 0.90), and low in the DIC patients (1.40 +/- 0.87) and healthy volunteers (0.84 +/- 0.26). There was no significant difference between the DIC patients with a good outcome and those with a poor outcome in terms of plasma TF levels, although the plasma TFPI level in the DIC patients with a good outcome (289 +/- 133 ng/ml) was significantly higher than that in those with a poor outcome (187 +/- 75 ng/ml). During the clinical course of DIC, plasma TF antigen was increased first, and an increase of the plasma TFPI level followed the increase in plasma TF level. These findings suggest that plasma TFPI is released from vascular endothelial cells and it may reflect vascular endothelial cell injury. It is conceivable that TF and TFPI may play an important role in the onset of DIC.

Anticoagulants↗

Ballistosporous yeasts found on the surface of plant materials collected in New Zealand. The genera Bensingtonia and Bullera with descriptions of five new species.

In the present study, strains from the surface of plant materials collected in New Zealand that belong to the genera Bensingtonia and Bullera are classified. One strain of Bensingtonia was assigned to Ben. ingoldii, while the remaining strain was assigned to Ben. naganoensis based on DNA-DNA reassociation experiment. Twenty-one of 28 Bullera strains were assigned to B. alba (11 strains), B. crocea (6 strains) and B. variabilis (4 strains). The remaining seven strains could not be assigned to any previously known species and were described as the new species, B. coprosmaensis (1 strain), B. hannae (1 strain), B. huiaensis (1 strain), B. mrakii (3 strains) and B. unica (1 strain).

Base Composition↗

Localization of bone morphogenetic protein-4 messenger RNA in developing mouse cochlea.

Bone morphogenetic protein-4 (BMP-4) is a cytokine that belongs to the TGF-beta superfamily. It has been implicated that it plays an important role during embryogenesis including epithelial-mesenchymal interactions and mesenchymal cells condensation. To investigate whether BMP-4 is involved in the embryogenesis of the inner ear, we performed in situ hybridization at various stages of the developing inner ear of mice. BMP-4 mRNA was detected only in the developmental stage. Its initial expression was detected in part of the otic vesicle at 9 days post-coitum (PC). As development proceeded, the hair cells of the cochlear duct were morphologically distinguishable. and BMP-4 expressing cells were found in Claudius cell region at 16 days PC. At this stage, the signal was most intense during development and the structure notably changed under the expressing cells. Mesenchymal cells were assembled and condensed underneath the BMP-4-expressing cells. The basilar membrane, with a rich extracellular matrix and elasticity, would be produced in the area between the Claudius' cells and condensed mesenchymal cells. Previous reports support the notion that BMP-4 expressed in the epithelium causes mesenchymal cell condensation and induces a structure with elasticity. In the developing cochlea. BMP-4 may be involved in the condensation and differentiation of the mesenchymal cells as well as basilar membrane formation. BMP-4 might be an essential factor for the normal development of the basilar membrane.

Animals↗

Agromyces mediolanus sp. nov., nom. rev., comb. nov., a species for "Corynebacterium mediolanum" Mamoli 1939 and for some aniline-assimilating bacteria which contain 2,4-diaminobutyric acid in the cell wall peptidoglycan.

In the course of identifying aniline-assimilating bacteria, researchers found some gram-positive strains that contain 2,4-diaminobutyric acid in their cell wall peptidoglycans and menaquinone 12 as the predominant menaquinone. "Corynebacterium mediolanum" and "Flavobacterium dehydrogenans" also are known to contain 2,4-diaminobutyric acid in their cell walls, as well as menaquinone 12, but the taxonomic position of these organisms has not been established previously. We found that the aniline-assimilating strains, together with "C. mediolanum" and "F. dehydrogenans," belong to a single species of the genus Agromyces, as determined by phenotypic characteristics, DNA-DNA relatedness data, and 16S ribosomal DNA sequence similarity data. The name Agromyces mediolanus sp. nov., nom. rev., comb. nov., is proposed for these organisms. The type strain of A. mediolanus is strain JCM 3346 (= ATCC 14004 = NCIMB 7206).

Actinomycetales↗

Improvement of hemolysis in muscle phosphofructokinase deficiency by restriction of exercise.

A 29-year-old woman with muscle phosphofructokinase (PFK) deficiency had exercise intolerance, painful cramps, elevation of muscle enzyme levels in the serum and compensated hemolysis. After the restriction of exercise, the creatine kinase level and indirect bilirubin level decreased, and the reticulocyte count and haptoglobin level were normalized. It is suggested that the hemolysis which was accelerated by exercise was improved by restriction of exercise.

Adult↗

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↗

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↗

Hemostatic abnormalities in patients with pulmonary embolism compared with that in deep vein thrombosis.

We investigated hemostatic abnormalities in 37 patients with deep vein thrombosis (DVT) and pulmonary embolism (PE) (PE patients) and in 40 patients with DVT without PE (DVT patients). Plasma fibrinogen, thrombin-antithrombin complex (TAT), plasmin-plasmin inhibitor complex, fibrin-D-dimer, activated protein C (APC)-protein C inhibitor (PCI) complex, von Willebrand factor (vWf), tissue plasminogen activator (t-PA), PA inhibitor-I (PAI-1), and thrombomodulin levels in both PE and DVT patients were significantly increased compared with normal volunteers. Plasma APC-PCI complex, PAI-1, and vWf levels in PE patients were significantly higher than those in DVT patients without PE. These findings indicate that PE patients are more hypercoagulable and hypofibrinolytic than DVT patients. Plasma TAT, APC-PCI complex, PAI-1, and vWf levels were the most sensitive indicators for PE. In these patients, increases in TAT and APC-PCI complex suggest DVT and increased PAI-1 and vWf suggest the risk of onset of PE.

Aged↗

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↗

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↗

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↗

Outcome of disseminated intravascular coagulation in relation to the score when treatment was begun. Mie DIC Study Group.

We examined 395 patients with disseminated intravascular coagulation (DIC) divided into two groups: non-leukemic and leukemic. In 58% of the patients as a whole, treatment of DIC resulted in complete or partial remission, while exacerbation and death occurred in 31%. The efficacy of DIC treatment in the non-leukemic group was less than that in the leukemic group, indicating that the outcome of DIC depended, in part, on the underlying disease. We examined hemostatic indicators in relation to DIC score: prothrombin time (PT) ratio, FDP, platelet count, and fibrinogen levels were found to be important indicators for the diagnosis of DIC, but not for Pre-DIC. Plasma levels of fibrin-D-dimer, thrombin-antithrombin complex (TAT), and plasmin-plasmin inhibitor complex (PPIC) were significantly increased in pre-DIC. The efficacy of treatment in relation to the DIC score when the treatment was begun showed that greater efficacy was achieved in pre-DIC than in DIC patients. The outcome was poorer with increasing DIC score, suggesting that early diagnosis and early treatment are important. On examining the relationship between outcome and hemostatic indicators, we found that the PT ratio and the levels of antithrombin, plasminogen, PPIC, the PPIC/TAT ratio, and thrombomodulin were related to outcome, suggesting that very high consumption of blood coagulation factors, liver dysfunction, hypofibrinolysis, or organ failure caused a poor outcome. Although the outcome in DIC patients may not depend substantially on plasma levels of TAT and fibrin-D-dimer, we can use these indicators to treat DIC patients at an early stage.

Antifibrinolytic Agents↗

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↗

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↗

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↗

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↗