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Biomedical subjects

T Yasuda

Publications and source records attributed to T Yasuda.

At least 217 records · Page 12Linked to original sources
PubMed1998

Cloning, sequence analysis and expression of the basidiomycete Lentinus edodes gene uck1, encoding UMP-CMP kinase, the homologue of Saccharomyces cerevisae URA6 gene.

Sequence analysis of the downstream region of the basidiomycete Lentinus edodes priB gene encoding a protein with a 'Zn(II)2Cys6 zinc cluster' DNA-binding motif (Endo, H., Kajiwara, S., Tunoka, O., Shishido, K., 1994. A novel cDNA, priBc, encoding a protein with a Zn(II)2Cys6 zinc cluster DNA-binding motif, derived from the basidiomycete Lentinus edodes. Gene 139, 117-121) suggested the presence of a Saccharomyces cerevisiae URA6 gene homologue encoding UMP kinase. We isolated a corresponding cDNA from a mature fruiting-body cDNA library of L. edodes. The nucleotide sequence of this was determined and compared with that of the genomic DNA, revealing that the URA6 gene homologue encodes 227 amino acids (aa) and is interrupted by four small introns. The deduced aa sequence showed an overall identity of 51.1% to that of the S. cerevisiae URA6 gene product. The URA6 homologue protein produced in Escherichia coli using the glutathione S-transferase gene fusion system was found to catalyze the phosphoryl transfer from ATP to UMP and CMP efficiently and also to AMP and dCMP with lower efficiencies. Thus, the URA6 gene homologue was designated uck1 and its product UMP-CMP kinase. Northern-blot analysis showed that the uck1 is actively transcribed in the gill tissue of mature fruiting bodies of L. edodes, implying that uck1 may play a role during the formation of basidiospores occurs in the gill tissue.

Amino Acid Sequence↗
PubMed1998

Phenotype 2 of deoxyribonuclease I may be used as a risk factor for gastric carcinoma.

BACKGROUND: Human deoxyribonuclease I (DNase I) (EC3.1.21.1) is one of the candidate nucleases that acts in mammalian cells during apoptosis. Genetic polymorphism of DNase I has been classified into 15 phenotypes controlled by 5 autosomal codominant alleles. The purpose of this study was to determine whether DNase I polymorphism is closely related to the incidence of gastric carcinoma. METHODS: The phenotype distribution was examined using urine samples obtained from unrelated Japanese patients with gastric carcinoma (n = 97) and benign gastric diseases (n = 76). Phenotyping was performed using isoelectric focusing electrophoresis in thin polyacrylamide gel and immunoblotting with an antihuman DNase I antibody. RESULTS: A close statistical association was found between patients with gastric carcinoma and a high frequency of DNase I phenotype 2. However, there was no significant difference in the phenotype distribution between the group of patients with benign gastric diseases and the controls. CONCLUSIONS: The findings of the current study suggest that DNase I phenotype 2 may be a marker for gastric carcinoma. Therefore, compared with other phenotypes, DNase I phenotype 2 may have potential for identifying patients who are at risk of harboring or developing gastric carcinoma.

Adult↗
PubMed1998

Chromosomal localization of a human deoxyribonuclease II gene (DNASE2) to 19p13.2-p13.1 using both the polymerase chain reaction and fluorescence in situ hybridization analysis.

Recently obtained information on the cDNA encoding human deoxyribonuclease II (DNase II) (T. Yasuda et al., 1998, J. Biol. Chem. 273, 2610-2616) has made it possible to demonstrate the precise position of the the human DNase II gene (DNASE2) on human chromosomes. Two different sets of oligonucleotide primers specific for human DNase II cDNA sequences were used to amplify unique DNA fragments in the human DNase II gene from a panel of human x rodent hybrid cell lines carrying different human chromosomes. Based on this analysis, DNASE2 was assigned to human chromosome 19. Furthermore, regional localization of the gene to 19p13.2-p13.1 was achieved by fluorescence in situ hybridization analysis using a full-length cDNA probe corresponding to the entire open reading frame.

Chromosome Mapping↗
PubMed1998

Interaction of genetic deficiency of endothelial nitric oxide, gender, and pregnancy in vascular response to injury in mice.

To begin to dissect atherogenesis as a complex genetic disorder affected by genetic makeup and environment, we have (a) generated a reproducible mouse model of neointimal growth; (b) evaluated the effect of disruption of a single gene, endothelial nitric oxide synthase, believed to be central to intimal growth, and (c) examined the modifying effects of gender and pregnancy upon the vascular response. Cuff placement around the femoral artery causes reproducible intimal growth. We assessed the response to injury by quantitative morphometry, measuring the intimal to medial (I/M) volume ratio. In wild-type mice, cuff placement causes pronounced intimal proliferation without affecting the media, resulting in I/M ratios of 31% (SV129 males) and 27% (C57BL/6 males). eNOS mutant male mice have a much greater degree of intimal growth (I/M ratio of 70%). Female mice show less intimal response than do males, although eNOS mutant female mice still have more response than do wild-type females. Most dramatic, however, is the effect of pregnancy, which essentially abolishes the intimal response to injury, even overriding the effect of eNOS mutation. We conclude that eNOS deficiency is a genetic predisposition to intimal proliferation that is enhanced by male gender, and that may be overridden by pregnancy.

Animals↗
PubMed1998

Newly synthesized Rho A, not Ras, is isoprenylated and translocated to membranes coincident with progression of the G1 to S phase of growth-stimulated rat FRTL-5 cells.

Ras and Rho are involved in the regulation of signal transduction events governing cell growth and cell proliferation. Protein prenylation is essential for the activation and/or the translocation of these small GTPases; however, protein geranylgeranylation rather than farnesylation is required for G1/S transition. We studied prenylation and translocation of Ras and Rho A during G1/S progression in growth-stimulated rat thyroid FRTL-5 cells. Immunoblot analysis revealed that both Ras and Rho A were detected in membrane fractions at G0. Rho A was eliminated from the membrane fraction during G1 and was not detected on the membrane at mid-G1. Translocation of Rho A from the cytoplasm back to the membranes was observed during late G1 phase. In contrast, Ras remains in the membrane fraction through the cell cycle progression from G1 to S phase. The immunoprecipitation of Rho A from the membrane fraction demonstrated that newly synthesized Rho A, labeled by pulsing cells with [35S]methionine and [35S]cysteine, was geranylgeranylated and associated with the membrane in late G1. These results indicate that Rho A, not Ras, was eliminated from membrane fraction during G1 progression and that newly synthesized Rho A is geranylgeranylated and translocated to membranes during G1/S progression in growth-stimulated FRTL-5 cells.

Animals↗
PubMed1998

Molecular cloning of the cDNA encoding human deoxyribonuclease II.

A rapid amplification of cDNA ends method, using degenerate oligonucleotides based upon the N-terminal amino acid sequence of human hepatic deoxyribonuclease II (DNase II), allowed a novel cDNA encoding DNase II to be constructed from thyroid gland RNA. The composite nucleotide sequence (1593 bases) included an open reading frame of 1080 bases, which encoded a single polypeptide of 360 amino acids (signal peptide, 16; propeptide, 91; mature protein, 253). Although the sequence of DNase II showed no significant homology to other mammalian proteins, its cDNA structural organization resembled those of the lysosomal cathepsin families. The two parts of the cDNA corresponding to the propeptide and the mature protein were expressed in Escherichia coli, and the recombinant polypeptides thus obtained were strongly stained with an anti-DNase II antibody on Western blotting. DNase II is ubiquitously expressed in human tissues, and the DNase II gene (DNASE2) was assigned to chromosome 19.

Amino Acid Sequence↗
PubMed1998

Clinicopathological features of chronic inflammatory demyelinating polyradiculoneuropathy in childhood.

The clinical, electrophysiological, and pathological findings, and the therapeutic characteristics in ten children with chronic inflammatory demyelinating polyradiculoneuropathy (CIDP), whose onset age was less than 16 years, were evaluated. The clinical progression pattern of the initial phase divided the patients into two groups. One group (six patients) showed a subacute progression for up to 2 months after onset and a subsided progression over 3 months. Three patients in this group had a preceding febrile episode. The other group (four patients) showed a chronic insidious progression for more than 3 months. The former group of patients revealed a favourable response to corticosteroid therapy as compared with the latter group. However, other clinical and laboratory features at the peak impairment were not distinguishable between these two groups. Motor dominant neuropathy was common to all patients, and only three cases showed sensory disturbance on the distal limbs. No cases revealed cranial nerve involvement. Motor and sensory nerve conduction and sural nerve biopsy studies revealed the demyelinating nature of the neuropathy. These clinicopathological features suggest that the subacute progression form frequently associated with prodromal episode and rather favourable corticosteroid response is characteristic in childhood CIDP, while the chronic insidious progression form is indistinguishable from the common adult CIDP.

Adolescent↗
PubMed1998

In vivo gene transfer into the adult mammalian central nervous system by continuous injection of plasmid DNA-cationic liposome complex.

Previously reported methods of liposome-mediated direct in vivo gene transfer have been inefficient, especially when performed with highly differentiated, quiescent cells of the adult mammalian central nervous system (CNS). We have therefore improved these procedures based upon a novel concept. Following continuous injection of plasmid DNA-cationic liposome complex which contained a reporter gene encoding E. coli beta-galactosidase into the striatum of adult rats, the expression of transgene was dramatically elevated without any adverse effects. This new technique may enable a wide application of liposome-mediated gene transfer technology not only to basic analysis of gene functions in the brain but also for clinical treatment of certain CNS disorders.

Animals↗
PubMed1998

Clustering of CMT1A duplication breakpoints in a 700 bp interval of the CMT1A-REP repeat.

The CMT1A-REP repeat is proposed to mediate unequal crossover leading to a 1.5 Mb duplication in chromosome 17p11.2-12 associated with Charcot-Marie-Tooth neuropathy type 1A (CMT1A). There is an apparent recombinational "hotspot" in the CMT1A-REP repeat since the majority of crossover breakpoints for CMT1A are located within a 1.7 kb interval. Further to characterize the crossover breakpoint region, we constructed PCR primers that specifically amplify the duplication breakpoint junctions in a series of Japanese and Caucasian CMT1A patients. We mapped the breakpoints in 89% of patients within a 700 bp interval of the CMT1A-REP repeat. This 700 bp region is 1.3 kb telomeric to a previously described mariner-like transposable element. Our observations further define the location of crossovers for CMT1A and provide additional evidence that this region is a recombinational "hotspot" within the CMT1A-REP repeat.

Asian People↗
PubMed1998

Detection of isozymes of deoxyribonucleases I and II on electrophoresed gels with picogram sensitivity using SYBR Green I.

A highly sensitive method for detecting deoxyribonucleases (DNases) I and II on an electrophoresed gel is described. A dried agarose film sheet containing DNA as a substrate and a buffer reagent was placed in contact with the gel surface after electrophoresis (DAFO method, Yasuda et al., Anal. Biochem. 1989, 183, 84-88). After an appropriate incubation period, the film sheet was peeled off and stained with SYBR-Green I (SG), and then the DNase isozyme bands were detected using a fluorescence image analyzer. We could detect pg levels of the DNases (DNase I, 2 pg; DNase II, 2pg), which represents a 32- to 128-fold increase in sensitivity compared with the original DAFO method using ethidium bromide (EB) as the fluorescent dye. A combination of this new detection method and isoelectric focusing electrophoresis in polyacrylamide gel allowed accurate DNase I typing from 1 microL human serum. This new technique has been named SG-DAFO, after its original dried agarose film overlay method using EB (EB-DAFO).

Benzothiazoles↗
PubMed1998

Limited surgery for early gastric cancer in cardia.

BACKGROUND: Because there are some difficulties with the diagnosis of invasion or the endoscopic resection technique, almost all gastric tumors are resected surgically. Surgeons now are performing a limited operation for early gastric cancer of the upper stomach (EGCUS) without lymph node metastasis. This paper discusses and evaluates the surgical technique and the results of the limited operation for EGCUS. PATIENTS AND METHODS: Since 1988, a total of 34 patients with EGCUS, diagnosed as intramucosal invasion, have undergone a limited operation--fundectomy--which includes a limited proximal gastrectomy, a limited lymph node dissection, and a procedure preserving the vagal nerve. The surgical risk, postoperative complications, and survival rates of the fundectomy patients (group A) were compared with those of patients undergoing a total gastrectomy for EGCUS (group B). RESULTS: Blood loss was lower in group A (300+/-193 mL) than in group B (555+/-316 mL) (P <.05). The incidence of postoperative pancreatic fistula also was lower in group A (0%) than in group B (15.0%) (P <.05). All patients in both groups (except one who died of a cerebral infarction) are alive without recurrence. CONCLUSION: Compared to the results of a total gastrectomy, performance of a limited fundectomy for EGCUS decreased surgical risk and postoperative complications without decreasing the survival rate.

Adult↗
PubMed1998

Cystic spinal cord tumors: magnetic resonance imaging correlated to histopathological findings.

We report the characteristics of magnetic resonance imaging (MRI) of cystic intradural extramedullary spinal cord tumors (cystic neurilemmoma, epidermoid cyst, and enterogenous cyst). T1-weighted MRI enhanced with gadolinium-DTPA clearly demonstrated the rim morphology of these tumors. The comparison between the rim enhancement pattern and histopathological findings offered possible qualitative diagnosis of these cystic spinal cord tumors by MRI.

Adult↗
PubMed1998

Indications for hepatectomy for hepatocellular carcinoma - what stage of the disease is the best indication for surgery?

To determine the clinical and tumor stage of hepatocellular carcinoma (HCC) that is the best indication for surgery, the postoperative long-term outcomes of patients who underwent hepatic resection were examined retrospectively. Of 975 patients with HCC who underwent regional therapy, 384 patients (39%) received hepatic resection (HR), 534 (55%) had transcatheter arterial chemoembolization (TACE), and the remaining 57 (6%) received percutaneous ethanol injection (PEI) into the tumor. The criteria defined by liver Cancer Study Group of Japan was used for staging and liver functional reserve (i.e., clinical staging). In the 133 patients with stage I HCC, there were no significant differences among the survivals of the HR, TACE, and PEI groups. In the 314 patients with stage II HCC, the 5- and 7-year survival rates were 51% and 46% in the HR group, 23% and 10% in the TACE group, and 0% and 0% in the PEI group. The survival of the HR group was significantly better than the survivals of the TACE and PEI groups (P < 0.001). The 5- and 10-year survivals of the stage II HCC patients who had HR were 64% and 47% in the clinical stage I (i.e., good liver function) group, significantly better than the 5; and 10-year survivals (32% and 23%) in the clinical stage II (i.e., bad liver function) group (P < 0.0001). Patients with good liver function in stage II are expected to have better survival and are considered to be the most suitable for HR.

Aged↗
PubMed1998

Advanced glycation end products co-localized with astrocytes and microglial cells in Alzheimer's disease brain.

In the previous study [Takeda et al. (1996) Neurosci Lett 221: 17-21], we reported that the advanced glycation end products (AGEs) in the external space of neuronal perikarya (extraneuroperikaryal AGE deposits) were significantly abundant in the Alzheimer's brain. In this study, we investigated the spatial relationship of the extraneuroperikaryal AGE (carboxymethyllysine and pentosidine) deposits in astrocytes and microglial cells in the Alzheimer's disease brain using double immunolabelling for AGEs and astrocyte or microglial cell markers. Most of the extraneuroperikaryal AGE deposits were co-localized with glial fibrillary acidic protein-positive astrocytes. AGE deposit-bearing astrocytes also contained Gomori-positive granules. Furthermore, some of the extraneuroperikaryal AGE deposits were co-localized with microglial cells. These extraneuroperikaryal AGEs may activate astrocyte and microglia, and play a role in pathogenesis of Alzheimer's disease.

Aged↗
PubMed1998

Fibrinolytic components in nasal mucosa and nasal secretion.

We evaluated a possible role for fibrinolytic components in nasal secretion by tissue localization with immunohistochemical techniques and by measuring their antigen concentrations in nasal discharge by means of ELISA and fibrin autography. Nasal mucosa was obtained surgically from the inferior turbinate. Urokinase-type plasminogen activator (u-PA) specific staining was observed in pseudostratified ciliated epithelium and was predominant in mucous cells of the seromucinous gland, while serous cells were almost devoid of stain. The pattern of staining of plasminogen activator inhibitor-2 was similar to that of u-PA. In contrast, plasminogen activator inhibitor-1 (PAI-1) immunoreactive material was localized exclusively in serous cells of seromucinous glands. Positive staining for tissue-type plasminogen activator (t-PA) was observed in endothelial cells and basal cells, which differentiate into either ciliated or goblet cells. Nasal secretions were partially fractionated by immunospecific antibody-immobilized Sepharose. Subsequent fibrin autography patterns indicated the presence of u-PA, PAI-1, and t-PA. After methacholine provocation, the level of t-PA increased transiently but decreased rapidly with subsequent challenges. These differential stainings of fibrinolytic components and the existence of PAs and PAI-1 in the nasal discharge suggest that the fibrinolytic system may play a role in the movement and fluidity of nasal secretion.

Autoradiography↗
PubMed1998

Myocardial oxygenation during terminal warm blood cardioplegia.

BACKGROUND: Terminal warm blood cardioplegia accelerates myocardial metabolic recovery. The process of myocardial oxygenation during terminal warm blood cardioplegia and its optimal administration are not clear. METHODS: We measured the myocardial tissue oxygen saturation (SO2) during reperfusion using near-infrared spectroscopy. Twenty-four dogs underwent 1 hour of ischemic arrest with cold crystalloid cardioplegia. They were then divided into four equal groups. Group 1 dogs received normal blood reperfusion. The other dogs received 15 mL/kg of terminal warm blood cardioplegia at 80 mm Hg in group 2 or at 60 mm Hg in group 3, and 30 mL/kg of cardioplegia at 60 mm Hg in group 4, followed by blood reperfusion. RESULTS: In group 1, the SO2 increased gradually during the early reperfusion and decreased transiently during the late reperfusion. In group 2, the SO2 increased rapidly but it decreased transiently during blood reperfusion. In groups 3 and 4, the SO2 increased rapidly and remained at high levels during the blood reperfusion. Reperfusion ventricular fibrillation occurred along with a SO2 decrease only in groups 1 and 2. The postischemic troponin-T levels of groups 3 and 4 were lower than that of group 1. The functional recovery in group 4 was better than those in the other three groups. CONCLUSIONS: Terminal warm blood cardioplegia accelerates the early SO2 increase and abolishes the SO2 decrease during subsequent reperfusion and reduces the incidence of reperfusion arrhythmia, suggesting that it ameliorates reperfusion injury and consequently improves postischemic functional recovery.

Animals↗
PubMed1998

Increased serum levels of advanced glycation end-products and diabetic complications.

We determined serum advanced glycation end-products (AGE) levels in patients with NIDDM and evaluated the relationship between these levels and diabetic complications. The subjects consisted of 125 patients (mean age, 59.2 +/- 11.1 years, duration of diabetes 11.6 +/- 8.9 years, mean HbA1c, 6.8 +/- 1.0%) with stable blood sugar control. Sixty-three healthy volunteers (mean age, 58.3 +/- 12.7 years) served as controls. Serum AGE were measured by a newly developed ELISA method. Serum AGE levels were significantly higher in the diabetic group compared with the normal control group (7.2 +/- 14.6 vs. 3.3 +/- 1.0 mU/ml, P < 0.05). Significant correlations were seen between serum AGE and the degree of diabetic nephropathy. Serum AGE levels of diabetic patients with proliferative retinopathy were significantly higher than those of patients without proliferative retinopathy (5.7 +/- 1.8 vs. 3.1 +/- 1.0 mU/ml, P < 0.025) in the patient groups whose serum creatinine levels were between 2.0 and 3.9 mg/dl, although serum creatinine levels of both groups were not significantly different. Serum AGE levels reflected the severity of diabetic complications, including nephropathy and retinopathy.

Aged↗