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T Miki

Publications and source records attributed to T Miki.

At least 451 records · Page 25Linked to original sources
PubMed1996

[Clinical studies of inverted papilloma of the bladder].

Clinical studies were conducted on 9 cases of inverted papilloma of the urinary bladder which were transurethrally resected between August, 1987 and July, 1995 at our hospital, in males between 29 and 81 years of age (mean:58.3). Six of the 9 inverted papillomas were localized at the bladder neck and 3 in the trigone. Cystoscopic examinations revealed that inverted papillomas were divided into two types, one with a thick and short stalk with a smooth surface and the other with a thin and long stalk with/without a partial papillary surface. The majority of the former was located in the trigone and all of the latter cases in the bladder neck, suggesting that the two types occurred at different sites. Pathological examination by Hematoxylin-Eosin staining demonstrated that 5 of the 9 cases were of the trabecular type and 4 were of the grandlar type. Immunohistochemically, none of the tumors were stained with the antiprostatic-specific-antigen antibody revealed. Follow-up periods after the operation were from 12 to 48 months(mean:26.6 months) and no recurrence was observed.

Adult↗
PubMed1996

The involvement of polyamines in the proliferation of cultured retinal pigment epithelial cells.

PURPOSE: To investigate the involvement of polyamines (putrescine, spermidine, and spermine) in the proliferation of retinal pigment epithelium (RPE) using cultured bovine RPE cells. METHODS: The polyamine content and the activities of rate-limiting enzymes in polyamine biosynthesis (ornithine decarboxylase [ODC] and S-adenosylmethionine decarboxylase [SAMDC]) and in polyamine biodegradation (spermidine spermine N1-acetyltransferase [SAT]) were measured after proliferative stimulation by 10% fetal calf serum (FCS). DNA synthesis was determined by [3H]thymidine incorporation into the acid-insoluble fraction after the addition of an inhibitor of ODC (alpha-difluoromethylornithine [DFMO]) or SAMDC (methylglyoxal bis[guanylhydrazone] [MGBG]). The effects of exogenous polyamines on DNA synthesis after the additions of inhibitors also were determined. RESULTS: ODC and SAMDC activities were elevated after stimulation by FCS and reached their peaks 16 hours and 4 hours, respectively, after the addition of FCS. SAT activity was not increased. Polyamine content was increased significantly after stimulation by FCS. DFMO did not inhibit DNA synthesis induced by FCS, and only putrescine content was decreased significantly among polyamines. However, MGBG inhibited DNA synthesis in a dose-dependent manner, and the amounts of spermidine and spermine were decreased significantly. Exogenous polyamines, especially spermine, restored MGBG-induced inhibition of DNA synthesis. CONCLUSIONS: Polyamines are essential for the proliferation of cultured bovine RPE cells. These data suggest that, of the polyamines, spermine has the greatest effect on DNA synthesis although other polyamines can substitute for spermine at higher concentrations with similar results. As for polyamine metabolism in RPE proliferation, it is possible that SAMDC is the key enzyme rather than ODC.

Acetyltransferases↗
PubMed1996

An intergenerational contraction of the CTG repeat in Japanese myotonic dystrophy.

We present the first report of a Japanese family with myotonic dystrophy (DM) that showed an intergenerational contraction of the CTG repeat. The size of the expanded CTG repeats was 3.2 kb for the father and 2.2 kb for the daughter, indicating that the expansion decreased during transmission from the father to the daughter. Despite the CTG repeat contraction, the daughter showed earlier age of onset than the father. However, she appeared to be less severely affected than the father. We discuss the correlation between the CTG repeat contraction and the clinical phenotype. The presence of the CTG repeat contraction in Japanese DM is important for genetic counseling of Japanese DM families.

Adult↗
PubMed1996

Infrared thermometry for rapid, noninvasive detection of reflux of spermatic vein in varicocele.

PURPOSE: We evaluated infrared thermometry for measurement of reflux of blood via the internal spermatic vein. MATERIALS AND METHODS: The change in scrotal temperature in patients with varicoceles and controls with different positions was measured with an infrared thermometer. RESULTS: Scrotal neck temperature in the patients increased during Valsalva's maneuver with upright position (mean plus or minus standard deviation 34.62 +/- 1.20 to 36.05 +/- 1.42C), while no statistically significant increase occurred in the controls (32.91 +/- 0.92 to 33.42 +/- 1.15C). Two weeks after high ligation of the internal spermatic vein the scrotal temperature in the patients decreased to the same level (0.59 +/- 0.84C) as in the controls. Using this method 2 subclinical varicoceles were also found on the right side in patients with a left varicocele. CONCLUSIONS: Infrared thermometry is noninvasive, rapid and simple for documenting varicoceles, including subclinical disease.

Adult↗
PubMed1996

Giant hydronephrosis of bilateral duplex systems associated with ureteral ectopia: a case report.

Giant hydronephrosis is an uncommon clinical entity. Even more uncommon is the association of giant hydronephrosis with a double collecting system and ectopic ureter. Here, we report a case of giant hydronephrosis of the bilateral duplex systems associated with ureteral ectopia. The patient underwent upper pole nephrectomy and upper ureterectomy. To our knowledge, only four similar cases have been reported previously.

Adult↗
PubMed1996

[A case of herniation through a defect in the falciform ligament at late pregnancy].

A very rare case of small bowel strangulation caused by herniation of a loop of ileum through a defect in the falciform ligament is reported. A 27-year-old woman in the 38 weeks and 5 days of pregnancy was admitted with a sudden onset of epigastralgia. Emergency laparotomy with cesarean section was performed. A strangulated loop of ileum was found to pass through a defect in the falciform ligament. The ligamentum teres was divided to release the obstruction and the irreversible strangulated loop was resected. The strangulation was considered to have occurred because a loop of small bowel compressed by gestational uterus passed through a congenital defect in the falciform ligament.

Adult↗
PubMed1996

[Linkage mapping].

Explore the source record for details and available documents.

Chromosome Mapping↗
PubMed1996

[A case report of an infundibular ventricular septal defect with severe right ventricular outflow tract obstruction due to aneurysm of the aortic sinus of valsalva].

This paper describes the case of a 46-year-old female. Upon contacting infective endocarditis at the age of 39 years, she was diagnosed with a ventricular septal defect (VSD). Because dyspnea gradually worsened, she was later hospitalized. Cardiac catheterization was performed and angiograms were taken, revealing an infundibular VSD accompanied by severe right ventricular outflow tract obstruction (RVOTO) due to aneurysm of aortic sinus of valsalva and to mild aortic regurgitation caused by prolapsing aortic valve. The operative procedure consisted of the closure of the aortic sinus fistula by continuous suture after excision of the aneurysmal sac and patch closure of the VSD without treatment of the prolapsing aortic valve. After the operation, RVOTO improved and aortic regurgitation disappeared. The patient was discharged and has since been well.

Aortic Aneurysm↗
PubMed1995

Spectroscopic identification of the heme axial ligation of cytochrome b558 in the NADPH oxidase of porcine neutrophils.

The combination of electron paramagnetic resonance (EPR), near-infrared magnetic circular dichroism (NIR-MCD) and resonance Raman (RR) spectroscopies at cryogenic temperatures has been used to identify the axial heme ligation of the low spin cytochrome b558 component of NADPH oxidase from porcine blood neutrophils. The EPR and NIR-MCD results indicate the presence of two distinct forms in frozen solution; one with a low field g-value at 3.23 and porphyrin(pi)-to-Fe(III) charge transfer maximum at 1660 nm and the other a low field g-value at 3.00 and porphyrin(pi)-to-Fe(III) charge transfer maximum at 1510 nm. On the basis of these properties and the RR studies, both are attributed to forms of cytochrome b558 with bis-histidine axial ligation. The origin of the observed heterogeneity, the location and identity of the specific histidines involved in ligating the heme, and the role of the heme prosthetic group in O2- production are discussed in light of these results.

Animals↗
PubMed1995

Control by phosphatidylglycerol of expression of the flhD gene in Escherichia coli.

We reported elsewhere that mutation in the pgsA gene, responsible for the synthesis of phosphatidylglycerol, repressed the synthesis of flagellin and caused the loss of motility of Escherichia coli (Tomura et al., FEBS Letters 329, 287-290, 1993). We now describe evidence for a decrease in promoter activity of the flhD gene, a master gene for flagellum synthesis, in the pgsA3 mutant. We constructed a plasmid with a promoter region of the flhD gene connected with the structure region of the lacZ gene. The activity of beta-galactosidase in the extract prepared from the pgsA3 mutant harboring the fusion plasmid was 30% of that in the wild type cells. This result means that phosphatidylglycerol is likely to be required for the initiation of transcription of the flhD gene. We also found that the motility-less phenotype of the mutant was partially suppressed by elevating incubation temperature. This suppression is caused by restoration of transcription of the flhD gene by high temperature. As the content of phosphatidylglycerol did not increase by elevating incubation temperature, we proposed that this suppression is caused by alternation of a physical structure of phospholipid bilayers in cytoplasmic membranes.

DNA-Binding Proteins↗
PubMed1995

Oxidative stress response in yeast: glutathione peroxidase of Hansenula mrakii is bound to the membrane of both mitochondria and cytoplasm.

The yeast Hansenula mrakii IFO 0895 induces glutathione peroxidase (GPx) when the cells are exposed to the oxidative stress such as lipid hydroperoxide, superoxide- and hydroxy radical-generating conditions. To clarify the localization of GPx in H. mrakii cell, distribution of the enzyme was investigated. After centrifugation of the yeast protoplast homogenates at 2500 x g for 10 min, 67% of total GPx activity was recovered from the supernatant (Sup. 1) and 33% was from the pellet (Pellet 1). When the Sup. 1 was fractionated by sucrose density gradient ultracentrifugation, GPx activity was essentially recovered from the mitochondria fraction. Submitochondrial localization of the enzyme showed that 95% and 2.5% of the enzyme was recovered from the inner and outer membrane, respectively. No GPx activity was detected neither in intermembrane space nor in matrix of mitochondria. On the other hand, at least 12% of total GPx activity was recovered from the purified plasma membrane which was obtained from the Pellet 1 by successive sucrose density gradient centrifugation. Thus, the GPx of H. mrakii is present in the inner and outer membrane of mitochondria as well as the plasma membrane.

Cell Membrane↗
PubMed1995

Expression of multidrug resistance-associated protein in NIH/3T3 cells confers multidrug resistance associated with increased drug efflux and altered intracellular drug distribution.

Multidrug resistance is a major obstacle to cancer treatment. Using an expression cDNA library transfer approach to elucidating the molecular basis of non-P-glycoprotein-mediated multidrug resistance, we previously established that expression of multidrug resistance protein (MRP), an ATP-binding cassette superfamily transporter, confers multidrug resistance (G. D. Kruh et al., Cancer Res., 54: 1649-1652, 1994). In the present study, we generated NIH/3T3 MRP transfectants without using chemotherapeutic drugs to facilitate the pharmacological analysis of the MRP phenotype. MRP transfectants displayed increased resistance to several lipophilic drugs, including doxorubicin, daunorubicin, etoposide, actinomycin D, vincristine, and vinblastine. However, increased resistance was not observed for Taxol, a drug for which transfection of MDR1 confers high levels of resistance. Verapamil increased the sensitivity of MRP transfectants relative to control transfectants, but reversal was incomplete for doxorubicin and etoposide, the drugs for which MRP conferred the highest resistance levels. For the latter two drugs, MRP transfectants, which were approximately 8- and approximately 10-fold more sensitive than control cells in the absence of verapamil, exhibited 3.8- and 3.3-fold relative sensitization with 10 microM verapamil, respectively, but remained approximately 2 and approximately 3-fold more resistant than control cells. Analysis of drug kinetics using radiolabeled daunorubicin revealed decreased accumulation and increased efflux in MRP transfectants. Confocal microscopic analysis of intracellular daunorubicin in MRP transfectants was consistent with reduced intracellular drug concentrations, and also revealed an altered pattern of intracellular drug distribution characterized by the initial accumulation of drug in a perinuclear location, followed by the development of a punctate pattern of drug scattered throughout the cytoplasm. This pattern was suggestive of a process of drug sequestration, possibly followed by vesicle transport. Both increased drug efflux and perinuclear drug accumulation are consistent with the reported localization of MRP in plasma and cytosolic membranes (N. Krishnamachary and M. S. Center, Cancer Res., 53: 3658-3663, 1993; M. J. Flens et al., Cancer Res., 54: 4557-4563, 1994). These results thus indicate that the drug specificity of MRP is quite similar to that of MDR1, but also suggest potential differences in Taxol specificity and the level of verapamil sensitivity. In addition, these results indicate that MRP functions to extrude drug from the cell, but additionally suggest the intriguing possibility that drug sequestration contributes to drug resistance by protecting cellular targets and/or contributing to drug efflux.

3T3 Cells↗
PubMed1995

Cloning and characterization of an ATBF1 isoform that expresses in a neuronal differentiation-dependent manner.

The human ATBF1 cDNA reported previously, now termed ATBF1-B, encodes a 306-kDa protein containing 4 homeodomains and 18 zinc fingers including one pseudo zinc finger motif. Here, we report the isolation of a second ATBF1 cDNA, 12 kilobase pairs long, termed ATBF1-A. The deduced ATBF1-A protein is 404 kDa in size and differs from ATBF1-B by a 920-amino acid extention at the N terminus. Analysis of 5'-genomic sequences showed that the 5'-noncoding sequences specific to ATBF1-A and ATBF1-B transcripts were contained in distinct exons that could splice to a downstream exon common to the ATBF1-A and ATBF1-B mRNAs. The expression of ATBF1-A transcripts increased to high levels when P19 and NT2/D1 cells were treated with retinoic acid to induce neuronal differentiation. Preferential expression of ATBF1-A transcripts was also observed in developing mouse brain. Transient transfection assays showed that the 5.5-kilobase pair sequence upstream of the ATBF1-A-specific exon (exon 2) supported expression of the linked chloramphenicol acetyltransferase gene in neuronal cells derived from P19 cells but not in undifferentiated P19 or in F9 cells, which do not differentiate into neurons. These results showed that ATBF1-A and ATBF1-B transcripts are generated by alternative promoter usage combined with alternative splicing and that the ATBF1-A-specific promoter is activated during neuronal differentiation.

Alternative Splicing↗
PubMed1995

The murine BCL6 gene is induced in activated lymphocytes as an immediate early gene.

The chromosomal translocation involving 3q27 is often detected in human B-cell lymphomas, especially diffuse lymphomas with a large-cell component. The BCL6 gene has been isolated from the chromosomal breakpoint in these lymphomas. Here we cloned the murine BCL6 (mBCL6) cDNA from the muscle cDNA library using the human BCL6 (hBCL6) cDNA as a probe. The predicted amino acid sequence was 95% identical to that of hBCL6. It contains six repeats of the Krüppel-like zinc-finger motif that are completely identical to those of hBCL6, indicating that the BCL6 gene is well conserved between humans and mice. Expression of the mBCL6 gene was ubiquitously detected in adult mouse tissues including lymphatic organs. Furthermore, it was induced in lymphocytes activated with phorbol ester and Ca2+ ionophore within 30 min after stimulation. This induction was not inhibited by treatment of the cells with a protein synthesis inhibitor, cycloheximide. These results suggest that BCL6 plays a role in activated lymphocytes as an immediate early gene.

Amino Acid Sequence↗
PubMed1995

Characterization of the promoter region of human BCL-6 gene.

The BCL-6 gene encodes a zinc finger-transcription factor and frequently is rearranged in diffuse large cell lymphoma. We have reported here the isolation of the 5'-flanking region of the human BCL-6 gene. Nucleotides sequence of 1.5 Kb promoter region contains TATA box but no CAAT box and a number of potential regulatory elements including CACCC, E-box, and GATA-1 sites. Studies of the promoter activity showed the first 657 nucleotides of the 5'-flanking region significantly drove transcription of the luciferase reporter gene in human Burkitt's lymphoma cell line.

Base Sequence↗