Search PubMed⌕ Search

Biomedical subjects

M Takagi

Publications and source records attributed to M Takagi.

At least 649 records · Page 36Linked to original sources
PubMed1990

Evaluation of a new enzyme immunoassay (TESTPACK ROTAVIRUS) for diagnosis of viral gastroenteritis.

TESTPACK ROTAVIRUS, a simple 10 min enzyme immunoassay, was compared with reversed passive hemagglutination assay (RPHA) and polyacrylamide gel electrophoresis of virus RNA (RNA-PAGE) for the detection of rotaviral antigens in feces from 104 diarrheal children. The results of TESTPACK ROTAVIRUS were identical with those of RNA-PAGE. Discordant results of RPHA were further examined by latex agglutination and electron microscopy and were finally decided to be negative. Pararotaviruses, adenoviruses and small round viruses were negative in the TESTPACK ROTAVIRUS.

Electrophoresis, Polyacrylamide Gel↗
PubMed1990

Cloning and expression of the Clostridium thermosulfurogenes glucose isomerase gene in Escherichia coli and Bacillus subtilis.

The gene that encodes thermostable glucose isomerase in Clostridium thermosulfurogenes was cloned by complementation of glucose isomerase activity in a xylA mutant of Escherichia coli. A new assay method for thermostable glucose isomerase activity on agar plates, using a top agar mixture containing fructose, glucose oxidase, peroxidase, and benzidine, was developed. One positive clone, carrying plasmid pCGI38, was isolated from a cosmid library of C. thermosulfurogenes DNA. The plasmid was further subcloned into a Bacillus cloning vector, pTB523, to generate shuttle plasmid pMLG1, which is able to replicate in both E. coli and Bacillus subtilis. Expression of the thermostable glucose isomerase gene in both species was constitutive, whereas synthesis of the enzyme in C. thermosulfurogenes was inducible by D-xylose. B. subtilis and E. coli produced higher levels of thermostable glucose isomerase (1.54 and 0.46 U/mg of protein, respectively) than did C. thermosulfurogenes (0.29 U/mg of protein). The glucose isomerases synthesized in E. coli and B. subtilis were purified to homogeneity and displayed properties (subunit Mr, 50,000; tetrameric molecular structure; thermostability; metal ion requirement; and apparent temperature and pH optima) identical to those of the native enzyme purified from C. thermosulfurogenes. Simple heat treatment of crude extracts from E. coli and B. subtilis cells carrying the recombinant plasmid at 85 degrees C for 15 min generated 80% pure glucose isomerase. The maximum conversion yield of glucose (35%, wt/wt) to fructose with the thermostable glucose isomerase (10.8 U/g of dry substrate) was 52% at pH 7.0 and 70 degrees C.

Aldose-Ketose Isomerases↗
PubMed1990

Nucleotide sequence and cloning in Bacillus subtilis of the Bacillus stearothermophilus pleiotropic regulatory gene degT.

The regulatory gene (degT) from Bacillus stearothermophilus NCA1503 which enhanced production of extracellular alkaline protease (Apr) was cloned in Bacillus subtilis with pTB53 as a vector. When B. subtilis MT-2 (Npr- [deficiency of neutral protease] Apr+) was transformed with the recombinant plasmid, pDT145, the plasmid carrier produced about three times more alkaline protease than did the wild-type strain. In contrast, when B. subtilis DB104 (Npr- Apr-) was used as a host, the transformant with pDT145 could not exhibit any protease activity. After construction of the deletion plasmids, DNA sequencing was done. A large open reading frame was found, and nucleotide sequence analysis showed that the degT gene was composed of 1,116 bases (372 amino acid residues, molecular weight of 41,244). A Shine-Dalgarno sequence was found nine bases upstream from the open reading frame. A B. subtilis strain carrying degT showed the following pleiotropic phenomena: (i) enhancement of production of extracellular enzymes such as alkaline protease and levansucrase, (ii) repression of autolysin activity, (iii) decrease of transformation efficiency for B. subtilis (competent cell procedure), (iv) altered control of sporulation, (v) loss of flagella, and (vi) abnormal cell division. When B. stearothermophilus SIC1 was transformed with the recombinant plasmid carrying degT, the transformants exhibited abnormal cell division. These phenomena are similar to those of the phenotypes of degSU(Hy) (hyperproduction), degQ(Hy), and degR mutants of B. subtilis. However, the amino acid sequence of the degT product (DegT) is different from those of the reported gene products. Furthermore, DegT includes a hydrophobic core region in the N-terminal portion (amino acid numbers 50 to 160), a consensus sequence for a DNA binding region (amino acid numbers 160 to 179), and a region homologous to transcription activator proteins (amino acid numbers 351 to 366). We discuss the possibility that the membrane protein DegT functions as a sensor protein and transfers the signal of environmental stimuli to the regulatory region of target genes to activate or repress transcription of the genes.

Bacillus subtilis↗
PubMed1990

Molecular cloning, nucleotide sequencing, and expression of the Bacillus subtilis (natto) IAM1212 alpha-amylase gene, which encodes an alpha-amylase structurally similar to but enzymatically distinct from that of B. subtilis 2633.

An alpha-amylase gene of Bacillus subtilis (natto) IAM1212 was cloned in a lambda EMBL3 bacteriophage vector, and the nucleotide sequence was determined. An open reading frame encoding the alpha-amylase (AMY1212) consists of 1,431 base pairs and contains 477 amino acid residues, which is the same in size as the alpha-amylase (AMY2633) of B. subtilis 2633, an alpha-amylase-hyperproducing strain, and smaller than that of B. subtilis 168, Marburg strain. The amino acid sequence of AMY1212 is different from that of AMY2633 at five residues. Enzymatic properties of these two alpha-amylases were examined by introducing the cloned genes into an alpha-amylase-deficient strain, B. subtilis M15. It was revealed that products of soluble starch hydrolyzed by AMY1212 are maltose and maltotriose, while those of AMY2633 are glucose and maltose. From the detailed analyses with oligosaccharides as substrates, it was concluded that the difference in hydrolysis products of the two similar alpha-amylases should be ascribed to the different activity hydrolyzing low-molecular-weight substrates, especially maltotriose; AMY1212 slowly hydrolyzes maltotetraose and cannot hydrolyze maltotriose, while AMY2633 efficiently hydrolyzes maltotetraose and maltotriose. Further analyses with chimeric alpha-amylase molecules constructed from the cloned genes revealed that only one amino acid substitution is responsible for the differences in hydrolysis products.

Amino Acid Sequence↗
PubMed1990

Immunohistochemical localization of glycosaminoglycans and proteoglycans in predentin and dentin of rat incisors.

We examined immunocytochemically the type and distribution of glycosaminoglycans and proteoglycans (PG) in predentin and dentin demineralized with EDTA after aldehyde fixation of rat incisors using (a) four monoclonal antibodies (1-B-5,9-A-2,3-B-3, and 5-D-4) which recognize epitopes in unsulfated chondroitin (C0-S), chondroitin 4-sulfate (C4-S), chondroitin 6-sulfate (C6-S), and keratan sulfate (KS) associated with the PG, and (b) monoclonal (5-D-5) and polyclonal antibodies specific for the core protein of large and small dermatan sulfate (DS) PG. Light microscope immunoperoxidase staining after pre-treatment of tissue sections with chondroitinase ABC localized the majority of stainable PG (C4-S, KS, DSPG, C0-S, and C6-S) in predentin and, to a lesser extent (C4-S and small DSPG), in the dentin matrix. The former site demonstrated relatively homogeneous PG distribution, whereas the latter site revealed that strong staining of C4-S and small DSPG was confined mostly to dentinal tubules surrounding odontoblastic processes, with only weak staining in the rest of the dentin matrix. These results indicate that there is not only a definite difference between PG of predentin and dentin but also a selective decrease in the concentration or alteration of these macromolecules during dentinogenesis and mineralization.

Animals↗
PubMed1990

Enhanced ultrastructural preservation of cartilage proteoglycans in the extended state.

We investigated the preservation of proteoglycan (PG) structure in rat epiphyseal cartilage using N-N-dimethylformamide (DMF) dehydration before embedding. After aldehyde fixation, specimens with and without routine osmium post-fixation were dehydrated in graded DMF and embedded in either Spurr's resin or Lowicryl K4M resin. Standard ethanol dehydration with Spurr or Lowicryl embedding techniques resulted in the formation of condensed PGs, called matrix granules. DMF dehydration before embedding greatly improved the preservation of PG structure and resulted in an extended appearance of PGs closely resembling the fine filamentous network of cartilage tissues processed by rapid freezing and freeze-substitution. However, en bloc staining of aldehyde-fixed specimens with cationic reagents before or during DMF dehydration induced the condensation of PGs and resulted in the formation of matrix granules. These observations demonstrate that DMF, a mild dehydration agent, dramatically improves PG preservation without a harmful effect on aldehyde-fixed PG structure and can be utilized regardless of routine post-fixation.

Animals↗
PubMed1990

Spontaneous resolution of multiple hemangiomas of the brain. Case report.

A case of multiple intracerebral hemangiomas is reported. The lesions were angiographically hypervascular and accompanied by marked perifocal brain edema. After removal of the main lesion and postoperative steroid administration, the rest of the lesions resolved spontaneously. Histologically, the lesion was composed of capillaries and fibromyxoid stroma. The distinctive clinical, radiological and histological features of this lesion are discussed in contrast to several other types of intracranial vascular tumors.

Adult↗
PubMed1990

[Familial gingival fibromatosis: report of a case].

One family of familial gingival fibromatosis was presented. Case 1 is an 11 years old girl. Gingival fibromatosis was noted by delayed eruption of permanent teeth. Fibromatosis was seen in whole gingiva and lower 1/2 to 1/3 of the tooth crowns was covered. Gingivectomy was performed. Case 2 was 42 years old man, who was father of case 1. Firstly gingival swelling was noted at the age of 10 years. He had operations of gingivectomy at the age of 28 years. It recurred and fibromatosis was seen in whole gingiva and lower 1/2 to 1/3 of the tooth crowns was covered. Cytogenetically no abnormality was seen in the chromosomes of both cases. Reported cases of familial and non-familial gingival fibromatosis in Japan were reviewed.

Adult↗
PubMed1990

[Heterogeneity in gingival fibromatosis].

Five cases of familial and idiopathic gingival fibromatosis were reported. One case exhibited peculiar histologic features, which consisted of active growth of the fibroblastic cells. One hundred and ninety-six cases of gingival fibromatosis, whose clinical and/or pathologic findings were known, were collected from foreign literatures. The heterogeneity in gingival fibromatosis was discussed.

Adult↗
PubMed1990

High-level secretion of a Rhizopus niveus aspartic proteinase in Saccharomyces cerevisiae.

The gene encoding an extracellular Rhizopus niveus aspartic proteinase I (RNAP-I) was introduced into Saccharomyces cerevisiae. The yeast cell carrying a plasmid containing the intact RNAP-I gene under the control of the glyceraldehyde 3-phosphate dehydrogenase (GAPDH) gene promoter of S. cerevisiae did not synthesize RNAP-I at all. On the other hand, when the intron of the RNAP-I gene had been removed from the gene in the plasmid, the cell secreted RNAP-I with high efficiency. Processing of the pro-sequence occurred at the same region of the pro-enzyme during cultivation as observed in the culture of R. niveus. Moreover, the promoter and the terminator of the original RNAP-I gene were found to be weakly functional in the yeast cell with respect to expression of the intronless RNAP-I gene, although the initiation and termination sites were heterogeneous. The effects of vector-types on the extracellular production of RNAP-I were also investigated.

Aspartic Acid Endopeptidases↗
PubMed1990

Isolation and some properties of acid phosphatase-1(1) from tomato leaves.

An isozyme of acid phosphatase-1, acid phosphatase-1(1), was purified from the leaves of tomato (Lycopersicon esculentum) to homogeneity and characterized. The purified enzyme was homogeneous on polyacrylamide gel electrophoresis with or without sodium dodecyl sulfate. The gel filtration analysis showed that the native molecule had a relative molecular mass of about 61 kilodaltons (kDa). The relative molecular mass of the subunit on gel electrophoresis with sodium dodecyl sulfate was about 32 kDa, indicating that the native form of the enzyme was a homodimer. It was suggested by periodic acid-Schiff staining on the gel that the enzyme was a glycoprotein. The Km for p-nitrophenylphosphate was 2.9 x 10(-3) M. The enzyme had a pH optimum of 4.5 in 0.15 M potassium acetate buffer with p-nitrophenylphosphate as a substrate. This enzyme was activated by divalent metal ions, such as Zn2+, Mg2+, and Mn2+. The N-terminal amino acids were sequenced after the purified enzyme was treated with pyroglutamylpeptidase. It was suggested that the N-terminal amino acid was pyroglutamate.

Acid Phosphatase↗
PubMed1990

Polyphosphate binding sites in Liophis miliaris hemoglobin. Evidence with reduced nicotinamide adenine dinucleotide phosphate.

The water-snake Liophis miliaris presents hemoglobin which binds organic polyphosphate through a simple single-site per tetramer (Mol. Wt. 64500) as judged by titration curves of reduced nicotinamide adenine dinucleotide phosphate either in the presence or absence of inositol hexaphosphate. The site seems to have the same structural nature of that found on other hemoglobins and is able to strongly bind most of the known protein effectors such as inositol hexaphosphate, adenosine triphosphate or 2,3-diphosphoglicerate. The high association constant at pH 7 of reduced nicotinamide for the deoxy hemoglobin of about K(D) = 7 x 10(6) M-1 compared to human hemoglobin (K(D) = 7 x 10(5) M-1), and to that of adenosine triphosphate (its natural erythrocytic polyphosphate) still higher of about K(D) = 10(11) M-1, shows clearly the very high affinity of this snake hemoglobin for such allosteric effector. The results besides corroborating the dimer-tetramer transition mechanism proposed to describe the oxygen transport by the hemoglobin of Liophis miliaris--may explain the difficulties to obtain the oxy dimeric conformation of the protein by usual hemolysis and stripped off procedures.

Adenosine Triphosphate↗
PubMed1990

Biocompatibility of zirconia dispersed hydroxyapatite ceramics.

Because of the lack of adequate strength and toughness, hydroxyapatite (HA) ceramic can not be used for a substitute for a bone and joint despite its excellent affinity for the bone. The present authors have succeeded in producing a new type of HA ceramic containing zirconia. This new ceramic material is superior to ordinary HA ceramic in quality and exceeds compact bone in bending strength and fracture toughness. The Young's modulus was about 3-4 times greater than that of compact bone. The new ceramic material contained either 1.6 or 50% of zirconia by volume and was produced using a special technique to disperse the metal dioxide. In order to assess their affinity for the bone, the new ceramic materials were implanted into rabbit femurs. Sections of the bones removed at different times after operation were prepared without decalcification and subjected to optical microscopy, scanning electronmicroscopy (SEM), and electron-probe X-ray microanalyser (EPMA). The formation of direct chemical bonds with the bone was seen without intervening membrane. Thus, the new ceramic material was shown to have an excellent affinity for the bone, comparable to that of ordinary HA ceramic.

Animals↗
PubMed1990

[Measurement of FDP-D-dimer in DIC and pre-DIC].

We measured FDP-D-dimer value in disseminated intravascular coagulation (DIC), pre-DIC (within 7 days before onset of DIC) and suspected DIC (not completely satisfying the DIC criteria). The level of FDP in many patients with pre-DIC was normal, but the level of FDP-D-dimer in most patients with pre-DIC was increased. FDP was markedly increased one day before onset of DIC but FDP-D-dimer was increased 7 days before the onset. FDP was significantly higher in DIC than in pre-DIC, but it was not higher in pre-DIC than in suspected DIC. In patients with hematological malignancies, FDP-D-dimer was statistically higher in DIC than in pre-DIC and in pre-DIC than in suspected DIC, but in non-hematological malignancies, FDP-D-dimer was not significantly different among the 3 groups. The peak increase of FDP-D-dimer was noted at a DIC score of 7 or 8. The correlation of FDP-D-dimer with FDP was better in pre-DIC than in DIC, and the ratio of FDP-D-dimer to FDP was higher in pre-DIC. FDP-D-dimer was not correlated with fibrinopeptide A or B beta 15-42 in pre-DIC. It is speculated that pre-DIC is a hypercoagulable state and FDP-D-dimer may be useful to the diagnosis of pre-DIC.

Disseminated Intravascular Coagulation↗
PubMed1990

Squamous cell carcinoma antigen in oral squamous cell carcinomas.

Squamous cell carcinoma (SCC) antigen is a tumor-associated antigen isolated from the squamous cell carcinoma of the uterine cervix. In order to estimate the usefulness of the SCC antigen in monitoring the clinical behaviors of oral squamous cell carcinomas, we analyzed clinicopathologically and immunohistochemically 54 cases of squamous cell carcinoma of the oral cavity. Elevated serum SCC antigen levels were detected in 23 (42.6%) out of 54 oral squamous cell carcinomas. The positive rate of serum SCC antigen levels was significantly higher in the patients with advanced clinical stages and poorly differentiated carcinoma. The serum levels declined rapidly after the surgical operation. It is considered that the serum SCC antigen levels could be useful in monitoring the extension, effectiveness of therapy, recurrence and metastases of the oral squamous cell carcinomas. Immunohistochemically, strong staining was seen in the cytoplasm of the well-differentiated carcinoma cells.

Antigens, Neoplasm↗
PubMed1990

[Elevated levels of cytokines in plasma from patients with disseminated intravascular coagulation].

We measured blood concentrations of tumor necrosis factor (TNF), interleukin-1 beta (IL 1-beta), soluble interleukin 2 receptor (s-IL 2r), and interferon alpha (IFN alpha) in 30 patients with disseminated intravascular coagulation (DIC) and compared the results to those of 25 patients without DIC. Plasma levels of TNF, IL 1-beta, and s-IL 2r were higher in patients with DIC than in those without DIC. In one case of acute promyelocytic leukemia, plasma levels of TNF and IL-1 beta increased at the onset of DIC but decreased upon DIC improvement. These findings suggest that activation of the immune system is involved in the development of DIC. However, these concentrations were not markedly increased in patients with leukemia, although blood TNF and s-IL 2 r were markedly elevated in patients with solid cancers. Especially in patients with solid cancers, hyperactivation of the immune system may cause an increase in blood TNF and IL-1 beta and the development of DIC.

Cytokines↗
PubMed1990

[Laboratory and clinical studies of cefodizime in pediatric field].

We have carried our laboratory and clinical studies on cefodizime (CDZM, THR-221). The results were summarized as follows. CDZM was given by 30-minute drip infusion to 2 children at a single dose of 10 mg/kg and to 2 children at a single dose of 20 mg/kg and to 3 children at a single dose of 40 mg/kg. After the 30-minute drip infusion, mean serum levels of CDZM obtained for the 3 dose levels were 76.16 +/- 5.52 micrograms/ml, 170.49 +/- 16.70 micrograms/ml, 270.01 +/- 50.44 micrograms/ml at the end of injection, respectively, and serum half-lives were 2.03 +/- 0.78 hours, 2.03 +/- 0.38 hours, 2.28 +/- 0.30 hours, respectively. The mean urinary excretion rate of CDZM were 83.3 +/- 22.3%, 73.1 +/- 13.9%, 51.1 +/- 8.5% in the first 8 hours after the 30-minute drip infusion of 10 mg/kg, 20 mg/kg, 40 mg/kg, 40 mg/kg, respectively. Treatment with CDZM was made in 28 cases of pediatric bacterial infections; 5 cases of tonsillitis, 2 cases of bronchitis, 10 cases of pneumonia, 6 cases of enteritis, 3 cases of urinary tract infection and 1 case each of maxillary sinusitis and laryngitis. Results obtained were excellent in 13 cases, good in 7 cases, fair in 2 cases, poor in 6 cases. No significant side effect due to the drug was observed except one case of thrombocytosis and 2 cases each of elevated GOT and elevated GOT and GPT.

Absorption↗