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T Ohno

Publications and source records attributed to T Ohno.

At least 271 records · Page 15Linked to original sources
PubMed1997

GTP-dependent modification of a 21-kDa substrate with NAD+ in bovine brain soluble fraction is not ADP-ribosylation of small G-protein but tailing of tRNA.

Labeling of 21-kDa material was observed when bovine brain soluble fraction was incubated with [adenylate-32P]NAD+ in the presence of GTP. The 21-kDa substrate, slightly smaller than C3 substrate in size, was labeled even without C3 exoenzyme. GTP could be replaced by nucleoside triphosphates other than ATP while ATP inhibited the GTP-induced labeling of 21-kDa substrate. After incubation of the soluble fraction with [adenylate-32P]NAD+ in the presence of GTP, [32P]ADP and [32P]ATP were detected in addition to [32P]AMP and [32P]ADP-ribose while only the last two nucleotides were observed without GTP. The 21-kDa substrate was labeled with [alpha-32P]ATP even in the absence of GTP, suggesting adenylylation rather than ADP-ribosylation. The labeled 21-kDa substrate, was extractable by phenol, disappeared with RNase treatment but not with tryptic digestion. Alkaline treatment of the phenol extract yielded an equal mixture of 3'-[32P]CMP and 2'-[32P]CMP. From these results we concluded that the 21-kDa labeling is a result of tRNA tailing with [alpha-32P]ATP generated from the [32P]AMP moiety of [adenylate-32P]NAD+. Results from reconstitution experiments using enzymes and tRNA purified from bovine brain soluble fraction, which are involved in this pathway, confirmed our conclusion.

ADP Ribose Transferases↗
PubMed1997

Frequent expression of Fas in gonadotropin-releasing hormone receptor-bearing tumors.

OBJECTIVE: Fas, a cell surface receptor, mediates cell death by means of apoptosis in a variety of cell types. Gonadotropin-releasing hormone (GnRH) receptor-bearing tumors undergo the apoptosis with GnRH analogs. The authors attempted to determine the frequency with which Fas is present in the GnRH receptor-bearing tumors. STUDY DESIGN: Surgically removed gynecological tumors were screened for GnRH receptor expression prior to analyses. Fas was characterized by immunoblotting of membrane proteins with the specific antibodies. Fas messenger ribonucleic acid (mRNA) was determined by reverse transcription-polymerase chain reaction using oligonucleotide primers synthesized according to the published Fas sequence. RESULTS: Immunoreactive Fas and Fas mRNA were detected in a high proportion (94.4%) of the specimens from endometrial carcinomas (8 of 9), ovarian carcinomas (7 of 7), and uterine leiomyosarcomas (2 of 2); all these expressed GnRH receptor. There was neither substantial Fas nor GnRH receptor in 9 cervical carcinomas. Cloned cell lines gave identical results to those obtained in their respective mother tumors. CONCLUSION: These data might suggest the frequent expression of Fas in the GnRH receptor-bearing tumors, but not in the GnRH receptor-negative tumors. Despite a poorly understood processes of apoptosis at present, there may be at least some similarity in signal transduction pathway utilized by GnRH analogs and Fas ligands.

Adenocarcinoma↗
PubMed1997

The RY sequence is necessary but not sufficient for the transcription activation of a winged bean chymotrypsin inhibitor gene in developing seeds.

A winged bean Kunitz-type chymotrypsin inhibitor (WCI) is expressed in seeds and tuberous roots. In seeds, the expression of WCI is restricted to the period between the mid- and late-maturation stage. To understand the mechanisms that regulate the expression of WCI genes, we analyzed the promoter activity of the upstream region of the WCI-3b gene, which encodes a major WCI protein, in transgenic tobacco plants. By using a series of constructs with 5' deletions in the upstream sequences, the region between -882 and -623, relative to the transcription start site, was shown to contain multiple sequences which are responsible for high level expression in mid-maturation stage seeds. However, when this region was fused to the cauliflower mosaic virus 35S core promoter in both orientations, the chimeric promoters showed only a weak transcription activity in transgenic tobacco plants. Further analyses using internal deletion constructs revealed that the region between -882 and -174 is required for the transcription activation. Disruption of the RY sequence at -517, which is conserved in many seed protein genes, resulted in a drastic reduction of the transcription activity in seeds. These results suggest that sequences necessary for high level induction of the WCI-3b gene transcription in developing seeds are dispersed in the region between -882 and -174, and that the RY sequence is one of these sequences.

Chymotrypsin↗
PubMed1997

Successful prevention of hematological relapse for a patient with Philadelphia chromosome-positive acute lymphoblastic leukemia after allogeneic bone marrow transplantation by donor leukocyte infusion.

Donor leukocyte infusion (DLI) was carried out on a 12-year-old girl with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ ALL) who received allogeneic bone marrow transplantation from an HLA-identical sibling. This is the first report of DLI use before the onset of hematological relapse monitored by the results of RT-PCR. This patient has been in CR for 11 months after BMT, suggesting this alternative treatment is promising for Ph+ ALL with positive reverse transcriptase-polymerase chain reaction (RT-PCR) following BMT.

Bone Marrow Transplantation↗
PubMed1997

Combination gene transfer to potentiate tumor regression.

Recent efforts to treat malignancy using gene transfer have met with varying degrees of success. In this paper, we report the results of studies using two recombinant adenoviral vectors to examine the efficacy of combination gene transfer to cause tumor regression in vivo. One of these vectors encodes the murine MHC class I gene, H-2Kb (ADV-Kb), which induces an immune response that stimulates tumor regression. The second vector encodes the human p21 cyclin dependent kinase inhibitor (ADV-p21). This gene product arrests cell cycle progression and prevents proliferation of tumor cells. Both vectors were tested in a murine model in vivo for antitumor effect. As previously shown, a significant reduction of tumor size was observed with each vector. Combination treatment, in which both vectors were administered, resulted in a trend toward a reduced tumor growth greater than with either vector alone. In order to characterize the mechanism of tumor regression, cytolytic T lymphocyte (CTL) assays against the allogeneic molecule, H-2Kb, were performed. Mice treated with ADV-Kb showed specific CTL activity against the H-2Kb molecule, demonstrating that the immune response against the H-2Kb gene product involved in tumor regression was potentiated by expression of the p21 gene which affects cell cycle progression.

Adenoviridae↗
PubMed1997

Cell-cycle-regulated transcription of A- and B-type plant cyclin genes in synchronous cultures.

Synchronously dividing cell cultures of Catharanthus roseus were used to isolate cDNAs for two mitotic cyclins, named CYS and CYM. The deduced protein sequence of CYS is similar to that of A-type cyclins, and CYM belongs to the group of B-type cyclins. In a fashion similar to the pattern of expression seen for A-type and B-type cyclins in mammalian cells, CYS is expressed before CYM in C. roseus cells during the cell cycle. CYS mRNA accumulated at the onset of S phase and disappeared early in the G2 phase, whereas CYM mRNA was detected in the G2 and M phases of the cell cycle. Tobacco homologs of the two genes showed similar cell-cycle dependent expression patterns in synchronous cultures of tobacco BY2 cells. In both systems, CYS was expressed much earlier in the cell cycle than most other plant A-type cyclins, and hence CYS along with the soybean cyc1GM can be classified into a distinct subclass. The activities of CYM and CYS promoters during the cell cycle were analyzed in stably transformed tobacco BY2 cells. Cyclin promoter sequences of 0.5 kb could confer the typical cell-cycle-dependent expression to the beta-glucuronidase (GUS) reporter gene: the CYS promoter directed S-phase-specific expression, whereas the CYM promoter drove M-phase-specific expression. These results indicate the important role of transcriptional regulation in the oscillations of cyclin mRNA levels during the cell cycle.

Cell Cycle↗
PubMed1997

Change of plasma 1,5-anhydro-D-glucitol levels after the onset of diabetes in spontaneous diabetes prone BB/Wor/(/)Tky rats.

Plasma 1,5-anhydro-D-glucitol (AG) is a marker of the diabetic state and also reflects the glycosuria induced by hyperglycemia but not by renal pathology. To investigate the benefits of the AG determination in order to diagnose diabetes in BB/Wor/(/)Tky rats, AG was measured in non-diabetic (n = 104) and diabetic (n = 113) BB/Wor/(/)Tky rats. AG was significantly higher in non-diabetic rats than in diabetic rats (25.2 +/- 9.3 vs 4.1 +/- 7.4 micrograms/ ml, mean +/- SD, p < 0.001). The best cut-off level for AG (8.5 micrograms/ml) was highly specific (100%) for ruling out diabetes and fairly sensitive (82.3%) to detect diabetes. Based on the AG cut-off levels, 90% of false-negative diabetic rats (18/20) were observed within 4 days after the onset of diabetes, which corresponded to 38.3% in diabetic rats (18/47) at that time. The false-negative diabetic rats and positive rats could be effectively distinguished based on the cumulative points given according to the urinary glucose after the onset of diabetes. 1 point for each cross [+] indicating glycosuria using the Testape, i.e. 2 or less points false negative and 4 or more points for diabetic rats in the first 4 days. In conclusion, there is a close inverse relation between the level of plasma AG and the amount of glycosuria detected just after the onset of overt diabetes in BB/Wor/(/)Tky rats.

Animals↗
PubMed1997

Infarct size-reducing effect of ischemic preconditioning is related to alpha1b-adrenoceptors but not to alpha1a-adrenoceptors in rabbits.

In rabbits and rats, both stimulation of alpha-adrenoceptors and ischemic preconditioning (PC) reduce infarct size. Activation of alpha1b-adrenoceptors play an important role in the PC effect on ventricular function in rats. However, the alpha1-adrenoceptors have not been reported to be related to the PC effect in rabbits, because the infarct size-reducing effect of PC is not blocked by the nonselective alpha-adrenoceptor antagonist, phenoxybenzamine (POB) or by the alpha1-adrenoceptor antagonist, BE2254. However, we speculated that alpha1b-adrenoceptors but not alpha1a-adrenoceptors may be related to the infarct size-reducing effect of PC in rabbit hearts. Thus we examined in rabbits whether the alpha1b-adrenoceptor blocker chloroethylclonidine (CEC), the alpha1a-adrenoceptor blocker 5-methylurapidil (5-MU), the selective alpha1-adrenoceptor antagonist bunazosin (BN), and the nonselective apha-adrenoceptor antagonist phenoxybenzamine (POB) can block the PC effect on infarct size. Eighty-eight anesthetized open-chest Japanese white male rabbits were subjected to 30-min coronary occlusion and 48-h reperfusion. In five PC groups, the rabbits were subjected to a single 5-min occlusion and 5-min reperfusion before 30-min sustained ischemia. In the PC groups, those with CEC (3 mg/kg, n = 10), 5-MU (3 mg/kg, n = 10), BN (0.3 mg/kg, n = 10), POB (4 mg/kg, n = 10), or placebo saline (n = 10) were pretreated before PC. In the non-PC groups, those with CEC (3 mg/kg, n = 7), 5-MU (3 mg/kg, n = 7), BN (0.3 mg/kg, n = 7), POB (4 mg/kg, n = 7), or placebo saline (n = 10) were pretreated before 30-min sustained ischemia. After a 48-h reperfusion, the infarct size was measured histologically and expressed as a percentage of the area at risk. PC caused a marked reduction of infarct size as compared with the non-PC control (10 +/- 3% vs. 42 +/- 2%; p < 0.05). The PC effect was completely blocked by CEC (36 +/- 2%) and by BN (42 +/- 4%) but not by 5-MU (14 +/- 1%) or POB (13 +/- 2%). None of the drugs by itself affected the infarct size. Stimulation of alpha1b-adrenoceptors but not of alpha1a-adrenoceptors during PC plays an important role in the PC effect on infarct size. This may explain the previous confusion concerning the PC blocking effect of various alpha1-blockers.

Adrenergic alpha-Antagonists↗
PubMed1997

Protective effects of polysaccharide fucoidin on myocardial ischemia-reperfusion injury in rats.

We tested whether polysaccharide fucoidin, which inhibits leukocyte rolling in the mesenteric venule, has protective effects in the rat myocardial 30-min ischemia and 6-h reperfusion injury model. Intravenous infusion of fucoidin (27 microg/kg/min from 10 min before to 6 h after reperfusion) significantly attenuated myocardial infarct size 6 h after reperfusion. In this ischemia and reperfusion heart model, expression of P-selectin (determined immunohistochemically) was observed on the venular endothelial cells in the heart 30 min after reperfusion and also was sustained after 6 h. Neutrophil infiltration as estimated by myeloperoxidase activity significantly increased 2 h after reperfusion and kept increasing with time until 6 h after reperfusion. Four-hour infusion of fucoidin after reperfusion significantly reduced neutrophil infiltration, whereas the 2-h infusion of fucoidin did not. These results indicate that neutrophil infiltration and myocardial injury are attributed to expression of P-selectin after reperfusion, and that one of the inhibitory mechanisms of fucoidin seems to be blockade of P-selectin-mediated neutrophil rolling on the vessel wall.

Animals↗
PubMed1997

Antibiotic-loaded hydroxyapatite blocks in the treatment of experimental osteomyelitis in rats.

A novel drug delivery system for osteomyelitis was developed in which a porous hydroxyapatite block (HAB) is loaded with antibiotic by a centrifugation method. In this study, implantation of HABs loaded with the aminoglycoside antibiotic, arbekacin, were tested in established Staphylococcus aureus osteomyelitis in the proximal tibia of rats after debridement of the marrow cavity. The animals were observed for radiographic signs of infection and tissue was examined histologically. The infections were also evaluated by bone cultures. Bacterial counts were statistically lower in rats implanted with an antibiotic-loaded HAB than in those given a drug-free HAB. Radiographical and histological observations also showed beneficial effects of the antibiotic-loaded implant. The results suggest that the centrifugation method for loading HABs provides a simple drug delivery system. These antibiotic-loaded HABs may be useful for filling grafts in osteomyelitis.

Aminoglycosides↗
PubMed1997

Interferon-alpha therapy for individuals with normal serum alanine aminotransferase levels before treatment.

While interferon (IFN) therapy is approved for patients with chronic hepatitis C infection, the effectiveness of IFN therapy for anti-hepatitis C virus (HCV)-positive individuals with normal ALT levels remains poorly understood. Twenty-five individuals (M:F = 9:16; age = 51.8 +/- 15.1 years) who showed a normal alanine aminotransferase (ALT) level (< 30 IU/L) at least 6 months before treatment and were positive for both anti-HCV and serum HCV-RNA by reverse transcription polymerase chain reaction (RT-PCR) were studied. Of these, 16 received IFN therapy for 24 weeks (780 million units total IFN-alpha 2b) and nine were followed for 12 months as controls. The serum HCV-RNA level was determined by bDNA assay and HCV genotype was detected by enzyme immunoassay. All were shown to have chronic hepatitis by liver biopsy. Six (37.5%) of 16 individuals lost serum HCV-RNA by RT-PCR 6 months after cessation of therapy (complete response; CR), while the remaining individuals were defined as non-responders (NR). Of the six individuals in the CR group, five had HCV type 2 infection, compared with none of 10 individuals in the NR group (P < 0.01). There was a trend towards a lower pretreatment viraemia level in the CR group than in the NR group. These data suggest that IFN therapy for individuals with HCV type 2 infection and normal ALT levels was effective.

Alanine Transaminase↗
PubMed1997

Long-term evaluation of a nonpulsatile mechanical circulatory support system.

Antithrombogenicity of a centrifugal pump (CP) developed in our institute is provided by a central balancing hole (BH) in the impeller. A current CP, the National Cardiovascular Center (NCVC)-2, was ameliorated to improve antithrombogenicity, whereby the BH diameter was widened to improve self washout flow velocity, and an edge of the thrust bearing was rounded off to minimize flow separation. Effects of these modifications were assessed in a long-term in vivo experiment. The antithrombogenicity, hemolytic property, and mechanical durability of the NCVC-2 were investigated in 3 goats. The NCVC-2 was installed paracorporeally between the left atrium and the aorta and driven as long as possible at rotating speeds of about 2,800 rpm. The NCVC-2 ran for 50, 200, and 367+ days. The mean bypass flow rates were 6.8, 5.0, and 5.3 L/min, respectively. Creatinine, blood urea nitrogen (BUN), glutamic-oxaloacetic transaminase (GOT), and glutamic-pyruvic transaminase (GPT) did not increase until one week before termination. Plasma free hemoglobin was kept to a level less than 15 mg/dl, except for the last week of the second case. These results indicate that the NCVC-2 has excellent antithrombogenicity, an acceptable hemolytic property and the necessary durability for prolonged use.

Alanine Transaminase↗
PubMed1997

Noninvasive pump flow estimation of a centrifugal blood pump.

A flow rate estimating method was investigated for a centrifugal blood pump developed in our institute. The estimated flow rate was determined by the power consumption, the rotating speed of the motor, and the hematocrit value. The power consumption and the rotating speed of the motor were measured with a wattmeter. The examinations were performed in a closed mock loop filled with goat blood with hematocrit values of 21.5%, 28%, 34%, and 42%. Measured values of blood viscosity were 2.47, 3.09, 3.71, and 5.07 mPa.s at a share rate of 37.5/s, respectively. A linear correlation between the power consumption and the pump flow rate was observed in all hematocrit values. But variations in hematocrit caused a difference in the flow rate up to 1.1 L/min at the same power consumption and rotating speed. Effects of blood viscosity on the flow estimation were corrected by the hematocrit value. The value of the coefficient of determination, R2, between the estimated flow rate and the measured flow rate was 0.988. These results may indicate that the flow estimating method calculated by the power consumption of the motor, the rotating speed, and the hematocrit value is useful in the clinical situation.

Animals↗
PubMed1997

[Clinical efficacy of lomefloxacin for associated infection in patients with hematological diseases].

We have studied the clinical effect of lomefloxacin (LFLX) for the documented infections in the patients with hematological disorders, and also analyzed the prophylactic usefulness of LFLX for the prevention of succeeding infection after the chemotherapy. Fifty five patients were entered in the trial, and 51 patients were eligible. Among 51 eligible patients, 40 patients were suffered from accompanied infections, and 11 patients were registered for the prophylaxis of the infection. In the group of documented infection, the ratio of out-patients was 62.5%, and 63.0% in prophylactic usage. In the treatment of the documented infection, LFLX was effective in 20 patients; the efficacy rate was 50.0%. In the prophylactic administration, LFLX was effective in 9 patients, yielded the efficacy rate of 81.8%. LFLX was effective for all 5 patients with urinary tract infection, in 10 out of 18 patients with respiratory tract infection (efficacy rate; 55.6%), in 5 out of 12 patients with fever from undetermined origin (41.7%), showed no effect for cholecystitis, colitis, and phlegmon. Bacteriological examinations revealed that all of the bacteria detected as pathogens were eradicated. The efficacy rate in the group of the malignant disorders such as leukemia/ lymphoma was smaller than that of non-tumorigenic diseases as aplastic anemia. As myelodysplastic syndrome (MDS), four infection-bearing patients and five patients with prophylactic usage were analyzed. The efficacy rate of LFLX was 50.0 and 80.0%, respectively, and the overall efficacy rate was 66.7%. All MDS patients without prophylactic administration failed to have infections. Thus, LFLX was thought to be useful in the prevention of succeeding infections after the chemotherapy. No clinical and laboratory adverse reactions were reported.

Adolescent↗
PubMed1997

[Pain suppressive effect of low power laser irradiation. A quantitative analysis of substance P in the rat spinal dorsal root ganglion].

The influence of low power laser irradiation on pain was studied by the quantification of substance P in the rat spinal dorsal root ganglion (DRG). Forty-one Sprague-Dawley rats were divided into three groups: control (n = 12), stimulated group (n = 16), and laser application group (laser group) (n = 13). Under pentobarbital anesthesia, the right sciatic nerve of rats was exposed. The sciatic nerve was stimulated electrically in the stimulated group and the laser group. The laser irradiation was continued during the electrical stimulation in the laser group. Immediately after the electrical stimulation with or without the laser application, DRG of the fourth to sixth lumbar spinal roots were excised. Immunohistochemical substance P staining and substance P-like immunoreactivity (SP-LI) quantification were done in the excised DRG. There was a statistically significant difference of SP-LI between the control group (14.9 +/- 5.02 pg/mg tissue) and the stimulated group (20.9 +/- 7.54 pg/mg tissue) (p < 0.05). There was no statistically significant difference between the control and the laser group (16.2 +/- 4.83 pg/mg tissue). These results suggest that the laser irradiation suppresses the excitation of the unmyelinated C-fibers in the afferent sensory pathway.

Analgesia↗
PubMed1997

Tetralogy of Fallot with absent pulmonary valve: evaluation with magnetic resonance imaging.

Two infants with tetralogy of Fallot with absent pulmonary valve were studied with electrocardiographically gated magnetic resonance imaging using a 1.5 T imaging system. In each case, imaging was performed successfully. The magnetic resonance imaging clearly demonstrated a rudimentary pulmonary valve, an aneurysmal pulmonary artery, and compression of the mainstem bronchi. Cine MRI revealed phasic compression of the bronchi by an aneurysmally dilated pulmonary artery. Magnetic resonance imaging produced high quality images and provided all of the anatomic information required for preoperative evaluation.

Bronchi↗