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T Minowa

Publications and source records attributed to T Minowa.

At least 19 recordsLinked to original sources
PubMed1992

Analysis of the promoter region of the rat D2 dopamine receptor gene.

To investigate the regulatory processes involved in the expression of the D2 dopamine receptor gene, a rat genomic clone was isolated using a 21-mer oligonucleotide probe made of exon 1 sequences. A 1.3-kb region including all of exon 1, its 5'-flanking region, and part of intron 1 was sequenced. S1 nuclease analysis indicated three consecutive nucleotides as the main transcription start sites; several weaker sites were also noted between 321 and 363 nucleotides upstream from the 3' end of exon 1. The promoter region lacks TATA and CAAT boxes and is rich in G+C content with several putative Sp1 binding sites. Transient expression assays using chimeric constructs of D2 promoter deletion mutants-chloramphenicol acetyl-transferase gene in the neuroblastoma cell line NB41A3 which expresses D2 binding sites indicated strong transcription enhancing activity between nucleotides -75 and -30 and silencing activity between nucleotides -217 and -76. DNase I footprinting studies using nuclear extract from NB41A3 suggested Sp1 binding to its consensus sequence at nucleotide -48 but inhibition of Sp1 binding at nucleotide -86 by the extract. The D2 promoter could not induce transcription of the heterologous CAT gene in C6 glioma, embryonal NIH 3T3, or hepatic Hep G2 cells. It is concluded that the rat D2 gene shares with the human D1A dopamine receptor gene several features typical of "housekeeping" genes but they are both tissue-specific, regulated genes. Unlike the D1A gene, however, the D2 gene has a strong preference for transcription initiation to three consecutive nucleotides.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1992

Molecular cloning of a glucoamylase gene from a thermophilic Clostridium and kinetics of the cloned enzyme.

Clostridium sp. G0005 produces a cell-bound glucoamylase (CGA). The gene encoding CGA has been sequenced. The deduced amino acid sequence begins with a putative 21-residue signal sequence for secretion of bacterial lipoproteins, which suggests that a putative CGA precursor is modified and secreted like other bacterial lipoproteins in Clostridium sp. G0005, and that the modified residue is important in the cell-bound form of mature CGA. Comparison of the amino acid sequence of the CGA precursor with known eukaryotic enzymes showed several regions of high similarity in spite of low similarity throughout the overall primary structure. CGA is the first bacterial glucoamylase to be cloned. The CGA gene was expressed in Escherichia coli cells with an inducible expression plasmid, in which the 5' non-coding region and the N-terminal coding region of the gene were replaced with the lac promoter. Kinetic studies of the cloned enzyme purified from E. coli were performed with a set of linear malto-oligosaccharides as substrates, and the subsite affinity was calculated from the kinetic parameters. CGA had typical kinetic properties for a glucoamylase, but this bacterial enzyme had higher isomaltose-hydrolyzing activity than other eukaryotic glucoamylases.

Amino Acid Sequence↗
PubMed1992

Characterization of the 5' flanking region of the human D1A dopamine receptor gene.

To study how the expression of the D1A dopamine receptor gene is regulated, a human genomic clone was isolated by using a rat cDNA as probe. A 2.3-kilobase genomic fragment spanning -2571 through -236 relative to the adenosine of the first methionine codon was sequenced. The gene has an intron of 116 base pairs in the 5' noncoding region, nucleotides -599 through -484 as determined by S1 mapping and reverse transcription-PCR. It has multiple transcription initiation sites located between -1061 and -1040. The promoter region lacks a TATA box and a CAAT box, is rich in G+C content, and has multiple putative binding sites for transcription factor Sp1. Thus, the promoter region of the human D1A gene has features of "housekeeping" genes. However, it also has consensus sequences for AP1 and AP2 binding sites and a putative cAMP response element. The ability of four deletion mutants of the 2.3-kilobase fragment to modulate transcription of the heterologous chloramphenicol acetyltransferase gene in the promoterless plasmid pCAT-Basic was determined. All mutants demonstrated substantial transcriptional activity in the murine neuroblastoma cell line NS20Y, which expresses the D1A gene endogenously. Transient expression assays suggested the presence of a positive modulator between nucleotides -1340 and -1102, and a negative modulator between -1730 and -1341. The four genomic fragments had no or very low transcriptional activity in NB41A3, C6, and Hep G2 cells, which are not known to express this gene. Thus, the human D1A gene belongs to the category of tissue-specific, regulated genes that have housekeeping-type promoters.

Base Sequence↗
PubMed1992

Mechanism of allosteric transition of bacterial L-lactate dehydrogenase.

The allosteric behaviour of L-lactate dehydrogenase (L-lactate:NAD+oxidoreductase, EC 1.1.1.27, LDH) from Bifidobacterium longum aM101-2 was studied by means of the subunit hybridization technique as well as X-ray crystallography. Homotropic allosteric response of the LDH activity was found against the concentration of its substrate, pyruvate. Heterotropic allosteric activation of the enzyme was induced by the addition of fructose 1,6-bisphosphate (FBP). Two mutant enzymes, which had either altered sensitivity to FBP or altered substrate specificity from pyruvate to oxaloacetate, were made by site-directed mutagenesis. Hybrid LDHs, between the wild and the mutant LDHs, were made by in vivo subunit hybridization using double transformation of Escherichia coli with two plasmids carrying either the gene of wild or mutant LDH. Introduction of only one desensitized mutant subunit to the LDH changed the characteristic of the wild enzyme to that of the mutant LDH. Kinetic studies on hybrid enzymes consisting of subunits having different substrate specificity indicated that there was a strong cooperative interaction among subunits. These results strongly support the idea that the allosteric change of the LDH fits the concerted-symmetry model proposed by Monod, Wyman, and Changeux. We analysed the crystallographic structure of the LDH having low affinity to substrate at 1.9 A resolution. By the comparison of the structure with that of other LDHs, we concluded that the conformational transition of the LDH was mainly caused by concerted rotations of subunits.

Allosteric Regulation↗
PubMed1992

[Evaluation of the correlation with preoperative left ventricular end-systolic volume index and postoperative exercise tolerance in the patient with aortic regurgitation].

Twenty-three male patients (49 +/- 11 years old) undergoing aortic valve replacement (AVR) for aortic regurgitation received the exercise tolerance test using bicycle ergometer at more than one year after AVR. Preoperative left ventricular end-systolic volume index (LVESVI) significantly correlated with tolerance time, peak VO2, anaerobic threshold (AT) during the exercise, and with serum noradrenaline (NAd) levels at rest. Then patients were divided into two groups: those with preoperative LVESVI < or = 70 ml/M2 (13 patients, group A), and those with LVESVI > 70 ml/M2 (10 patients, group B). All patient in group A achieved more than 75 W of the exercise, however only one in group B achieved this level. The increase of VO2 in group B with an increasing exercise was significantly suppressed compared to group A, and then, the peak VO2 levels in group B were significantly lower than in group A (A: 20.9 +/- 3.7, B: 11.4 +/- 3.9 ml/kg/min). In addition group B showed a less increase of AT levels (A: 10.6 +/- 2.9, B: 6.8 +/- 2.3 ml/kg/min). In contrast, serum lactate and NAd levels in group B increased significantly at 50 W of the exercise compared to group A (A: 12.5 +/- 3.7, 332.3 +/- 104.2; B: 17.5 +/- 5.7 mg/dl, 746.7 +/- 324.3 pg/ml, respectively) though a significant difference of NAd levels before the exercise was observed between the both groups (A: 173.7 +/- 34.2, B: 329.0 +/- 132.1). In conclusion, group A showed a better exercise tolerance physiologically and biochemically compared to group B.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1992

[A case of tricuspid pouch associated with ventricular septal defect and functional left ventricular-right atrial communication].

We reported a 60-year-old woman with tricuspid pouch associated with ventricular septal defect and subsequent left ventricular-right atrial communication. Preoperative angiographic findings suggested the presence of membranous septal aneurysm, ventricular and atrial septal defects, and tricuspid insufficiency. However, at operation, besides perimembranous inlet type ventricular septal defect, a pouch, 1.5 cm in diameter was found in the adjacent part to the septal leaflet within the anterior one of the tricuspid valve. The ventricular septal defect was closed with a patch. From these findings, it is speculated that the tricuspid pouch was formed by the effect of jet stream through the ventricular septal defect.

Diagnosis, Differential↗
PubMed1991

Blood and brain tissue gaseous strategy for profoundly hypothermic total circulatory arrest.

Brain tissue carbon dioxide tension, pH, and oxygen tension were measured in dogs undergoing hypothermic circulatory arrest below 20 degrees C with three types of blood gas manipulation. During core cooling, dogs were given pure oxygen (group I, n = 8), 5% carbon dioxide in oxygen (group II, n = 10), or 7% carbon dioxide in oxygen (group III, n = 4). During core cooling, brain tissue carbon dioxide tension decreased significantly in group I. During circulatory arrest, carbon dioxide tension rose by 21.5 mm Hg in group I, 35.3 mm Hg in group II, and 57.0 mm Hg in group III, nearly doubling in each group. From the last 5 minutes of core cooling to the end of rewarming, carbon dioxide tension was significantly higher in groups II and III than in group I. Brain tissue pH fell by 0.33 to 0.35 during 60 minutes of circulatory arrest and did not recover in groups II and III. Brain tissue oxygen tension decreased significantly during the latter two thirds of the circulatory arrest period in all three groups. To reduce progressive tissue hypercapnia and acidosis during and after circulatory arrest, a more hyperventilatory manipulation of blood gases than that achieved by alpha-stat strategy was thought beneficial for core-cooling perfusion.

Acidosis↗
PubMed1990

[A case of isolated congenital diverticulum of the left ventricule].

Congenital diverticulum of the left ventricule is rare congenital cardiac malformation and is classified as muscular and fibrous. Muscular diverticula are usually accompanied with other cardiac and extracardiac malformations. 8 years old boy involved with muscular left ventricular diverticulum with no other congenital anomalies underwent resection of diverticulum. The cardiopulmonary bypass was required because it was not feasible to apply a clamp, to the neck of the diverticulum. Congenital diverticulum of the heart should be resected as soon as possible because of crisis of spontaneous rupture and systemic embolization. However, the assessment of cardiac arrhythmias and hemodynamic changes caused by clamping of the diverticulum during operation is necessary.

Cardiopulmonary Bypass↗
PubMed1990

[Right ventricular thrombosis due to familial heparin cofactor II deficiency].

This case report was with regard to familial heparin cofactor II (HC II) deficiency. The patient was a 14-years-old female, having complaints of chest pain, fever and swelling of right lower extremity. Echocardiography and DSA showed a pediculated mass at the right ventricular outflow tract which highly suggested a ventricular myxoma. At surgery, a large pediculated thrombus was removed from the RV conus septum aun pulmonary valve. The mass was identified as thrombus by histological examination. Two months later, the RV thrombi recurred with additional pulmonary embolus to the left lung. HC II was discovered by hemo-coagulation tests. Her HC II antigen value was 48%, and 32% on repeat study. Her brother's HC II antigen value was 53%. At reoperation, small thrombi less than phi 10 mm, were removed from the RV outflow tract and pulmonary valve. Fresh frozen plasma was given and intravenous urokinase therapy was taken. She is doing well with therapy of oral warfarin, aspirin and ticlopidine for anticoagulation.

Adolescent↗
PubMed1989

Sequence and characteristics of the Bifidobacterium longum gene encoding L-lactate dehydrogenase and the primary structure of the enzyme: a new feature of the allosteric site.

The gene ldh, encoding L-lactate dehydrogenase (LDH; EC 1.1.1.27) of Bifidobacterium longum aM101-2, was cloned in Escherichia coli using an oligodeoxyribonucleotide hybridization probe. The amino acid (aa) sequence, deduced from the sequence of the cloned DNA, was consistent with the results of protein chemical analysis of B. longum LDH. The transcription start points (tsp) in B. longum were identified by S1 nuclease mapping. A sequence, GTAGCAA-(14 bp)-TTATAGA, which is located a few bp upstream from the tsp, was assigned as the promoter of this ldh gene. In the 3'-noncoding region, there were two structures that strongly resembled the Rho-independent transcriptional termination signal of E. coli. Therefore, the B. longum ldh gene might form a monocistronic unit. The deduced primary structure of B. longum LDH had 40% identity with LDHs from Thermus caldophilus, Bacillus stearothermophilus, Lactobacillus casei and dogfish muscle. Most bacterial LDHs are allosterically regulated by fructose 1,6-bisphosphate (FBP), while the vertebrate LDHs are not. The anion-binding site of vertebrate LDHs has been thought to correspond to the FBP-binding site of bacterial LDHs. Although the B. longum LDH was regulated by FBP, the charge properties of aa residues in the putative FBP-binding site of the LDH were closer to those of the vertebrate LDHs than to those of bacterial LDHs.

Allosteric Site↗
PubMed1989

Crystallization of and preliminary crystallographic data for allosteric L-lactate dehydrogenase from Bifidobacterium longum.

L-Lactate dehydrogenase from Bifidobacterium longum aM101-2 was overexpressed in Escherichia coli and then purified. The enzyme was crystallized from a polyethylene glycol 6000 solution by the hanging drop vapor diffusion method. Crystals grown in the presence of NADH (type II), both NADH and oxamate (type III), and NADH, oxamate, and FBP (type IV) were analyzed. All three crystal forms belong to the orthorhombic system, space group P2(1)2(1)2. The cell dimensions of the type II crystals were a = 106.2 A, b = 131.6 A, and c = 63.8 A. Those of the type III and type IV crystals were a = 106.4 A, b = 131.4 A, and c = 63.8 A. The type III crystals diffract X-rays to beyond 2.5 A spacing. The type II and type III crystals were stable as to X-ray irradiation.

Allosteric Site↗
PubMed1984

[Evaluation of serum tissue polypeptide antigen (TPA) in patients with urogenital cancer].

The level of serum TPA was determined by radio-immunoassay in 19 healthy subjects and 90 patients with urogenital cancer. The normal level of serum TPA was 86 +/- 24 U/l, and the level of more than 134 U/l was determined positive. The positive rate of TPA was 38.9% in 90 patients, while that of CEA was 25.6%. In 19 patients with bladder tumor and 7 with testicular tumor, the positive rates of TPA were 52.6% and 71.4%, respectively, and the level of serum TPA was high in these positive patients. Considering the low positive rate of CEA, TPA may be a more useful marker than CEA in patients with bladder tumor and testicular tumor. Serial determinations of serum TPA and CEA showed the considerable variation of serum TPA compared with serum CEA and a temporary elevation of serum TPA following radical nephrectomy and retroperitoneal lymphadenectomy. However, the level of serum TPA fell significantly after the successful treatment in 8 patients (2 with renal cell cancer, 3 with bladder tumor, 1 with prostate cancer, 2 with testicular tumor) and rose sharply with recurrent or metastatic disease in 4 patients (2 with bladder tumor, 2 with testicular tumor). Although there was no correlation between the levels of serum TPA and serum PAP, the level of serum TPA tended to change in parallel with the level of serum AFP or HCG in 3 patients with testicular tumor.

Adenocarcinoma↗
PubMed1983

Evaluation of multidisciplinary treatment of bladder cancer, especially in chemoimmunotherapy (ADM and OK-432) as a consolidation therapy.

The relapse rate of bladder cancer (transitional cell Ca) is said to be about 45%-80% even after tumor resection. Multidisciplinary treatment was designed and studied to prevent such recurrence. This treatment was designed to have three steps: induction, consolidation, and maintenance therapy. Following surgical tumor removal, OK-432 and Adriamycin (ADM) were administered as consolidation therapy, followed by administration of PSK and carboquone (CQ) in small amounts as maintenance therapy continuously for about 3 years, and the course was observed. In both consolidation and maintenance groups various non-specific immunoparameters were superior in groups receiving combined immunotherapeutic agents. Thus, the use of immunotherapeutic agents in combination with chemotherapeutic agents was considered to be effective. The 3-year recurrence rate was only 8% in the multidisciplinary treatment group, while that in the non-multidisciplinary treatment group was 61%. This approach, especially with chemoimmunotherapy (ADM and OK-432) as a consolidation therapeutic mode, is therefore considered to be useful for the prevention of recurrence.

Adjuvants, Immunologic↗