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Biomedical subjects

T Inoue

Publications and source records attributed to T Inoue.

At least 361 records · Page 20Linked to original sources
PubMed2001

Cardiac pacing as emergency care for serious bradyarrhythmia with circulatory shock.

Three cases of bradyarrhythmia with serious illness of extracardiac organs are reported. Case 1 had sick sinus syndrome. He was admitted to our hospital complaining of syncope and developed apnea. Case 2 had complete atrioventricular block and serious hepatic failure in the hospital. Case 3 had paroxysmal atrioventricular block. He complained of syncope which followed convulsions. Their symptoms might be due to circulatory shock caused by a lazy lower pacemaker from the ventricle. Emergent temporary pacing successfully improved the extracardiac organ dysfunction. Although their bradyarrhythmias were transient, permanent pacemakers were implanted to inhibit the recurrence. A quick temporary pacing should be indicated in patients with critical bradyarrhythmia like our cases for survival.

Aged↗
PubMed2001

Modal analysis of the maxillary dentition in cleft lip and palate patients before and after bone grafting.

The aim of this study was to analyze the vibratory characteristics in the maxillary dentition of 4 cleft lip and palate (CLP) patients before and after bone grafting. First, the central incisor on the noncleft side was impacted with an impact hammer, and the responses were received using an acceleration sensor from the teeth between the upper first molars on both sides. The transfer functions were then obtained from each measurement point using a fast Fourier transform analyzer. Finally, a computer analysis and simulation were performed based on the measured transfer functions to obtain the natural frequency, modal shape, decay rate (DR) and maximum displacement (MDP). Before bone grafting, distinct phase differences between the major and minor dental arches (MDA and mDA) were observed in the modal shapes. After surgery, however, both the MDA and mDA vibrated in phase. These results were identical in all subjects. The MDPs of the central incisors conspicuously decreased after bone grafting in 3 subjects. From the standpoint of vibratory characteristics, this study indicated that bone grafting had a favorable effect on prosthodontic treatment using a fixed prosthesis across the cleft in CLP patients.

Acceleration↗
PubMed2001

[Calcium dynamics in the neuron (influx and efflux)].

The advance of optical methods has enabled measurement of calcium dynamics at single spine level. The molecular bases of the calcium influx and efflux mechanisms are becoming clearer, as well. Information about calcium storage and release functions of ER and mitochondria is also accumulating. This article surveys these topics in the neuron.

English Abstract↗
PubMed2000

The effects of sulfhydryl blockers and metal ions on nickel accumulation by rat primary hepatocyte cultures.

Previously, we found that nickel (Ni) accumulation by rat hepatocytes involves Ca channel transport processes. However, other mechanisms responsible for Ni accumulation are still unclear. Therefore, in the present study we examined the effects of sulfhydryl (SH) blockers on Ni accumulation by hepatocytes. Hepatocytes were exposed to various concentrations of N-ethylmaleimide (NEM) (0.5, 1 or 2 mM) or monoiodoacetic acid (MIA) (0.1, 0.25 or 0.5 mM), potent blockers of SH ligands, for 30 min and subsequently exposed to 10 microM NiCl(2) for an additional 60 min. Pretreatment with NEM and MIA enhanced the Ni accumulation by hepatocytes to maximum of 156 and 73%, respectively. The effects of essential and nonessential metal ions on Ni accumulation were also investigated. Pretreatment with 10 microM of Cu, Zn, Co, Cd and Mn, decreased Ni accumulation by 46, 30, 20, 18 and 11%, respectively. In contrast, pretreatment with Hg (10 and 20 microM) enhanced the Ni accumulation by almost 81 and 140%, respectively. Furthermore, significant decrease in SH concentration in the hepatocyte membrane was observed by the treatment with NEM, MIA and Hg, but not with Cu, Zn and Cd. These results suggest that Ni accumulation by hepatocytes does not appear to be dependent on the SH carrier-mediated transport processes, and that to block the SH ligands in the plasma membrane may facilitate the Ni crossing of the cell membrane.

Animals↗
PubMed2000

Electrochemical detection of thiols with a coenzyme pyrroloquinoline quinone modified electrode.

A modified electrode sensor for the detection of thiols is described. The sensor was constructed by incorporation of the coenzyme pyrroloquinoline quinone (PQQ) into a polypyrrole (PPy) film on a glassy carbon electrode substrate by the electropolymerization of pyrrole in the presence of PQQ. The electrochemical properties of entrapped PQQ in the PPy film were influenced by the applied potential during electropolymerization and by film thickness, both of which were optimized to yield a stable and reproducible response for entrapped PQQ. The PQQ/ PPy sensor was utilized for the amperometric detection of cysteine, homocysteine, penicillamine, N-acetylcysteine, and glutathione. The response for each thiol in pH 8.42 borate buffer was found to be linear with detection limits (S/N = 3) ranging from 13.2 microM for glutathione to 63.7 nM for cysteine with sensitivities of 0.023 nA/microM and 4.71 nA/microM, respectively. The response and detection limits were found to be sensitive to the nature of the thiol and the solution pH. Furthermore, in the presence of dopamine, ascorbic acid, or uric acid, the pH-dependent redox potential of the PQQ catalyst allows tuning of the detection potential to enhance the selectivity for thiols over these potential electroactive interferences.

Coenzymes↗
PubMed2000

The Caenorhabditis elegans heterochronic gene lin-29 coordinates the vulval-uterine-epidermal connections.

BACKGROUND: The development of a connection between the uterus and the vulva in the nematode Caenorhabditis elegans requires specification of a uterine cell called the utse, and its attachment to the vulva and the epidermal seam cells. The uterine pi cells generate the utse and uv1 cells, which also connect the uterus to the vulva. The uterine anchor cell (AC) induces the vulva through LIN-3/epidermal growth factor (EGF) signaling, and the pi cells through LIN-12/Notch signaling. Here, we report that a gene required for seam cell maturation is also required for specification of the utse and for vulval differentiation, and thus helps to coordinate development of the vulval-uterine-seam cell connection. RESULTS: We cloned the egl-29 gene, which is necessary for induction of uterine pi cells, and found it to be allelic to lin-29, which encodes a zinc finger transcription factor that is necessary for the terminal differentiation of epidermal seam cells. In the uterus, lin-29 functioned upstream of lin-12 in the induction of pi cells and was necessary to maintain expression in the AC of lag-2, which encodes a ligand for LIN-12. CONCLUSIONS: The lin-29 gene controls gene expression in the epidermal seam cells, uterus and vulva, and may help to coordinate the terminal development of these three tissues by regulating the timing of late gene expression during organogenesis.

Amino Acid Sequence↗
PubMed2000

Comparison of activation process of platelets and neutrophils after coronary stent implantation versus balloon angioplasty for stable angina pectoris.

The pathophysiologic features of stent-induced cellular responses of platelets and leukocytes have not been established. This study was designed to clinically investigate the activation of platelets and neutrophils after coronary stenting and to identify its effects on the long-term results of coronary stents. Forty-eight consecutive patients with left anterior descending coronary artery disease indicating coronary intervention were randomly assigned to either a balloon angioplasty group or a coronary stent group. Flow cytometric analysis demonstrated that the transcardiac gradient (the value of coronary sinus blood minus the value of peripheral blood) of platelet surface expression of CD62P (p < 0.001) and CD63 (p < 0.01) increased immediately after coronary stenting, but increased less significantly immediately after balloon angioplasty (CD62P, p < 0.01; CD63, p < 0.05). These increases were persistently observed after coronary stenting but transiently after balloon angioplasty alone during a 48-hour observation period after the procedures. The gradient for neutrophil surface expression of CD11b increased, and that of CD62 L decreased 48 hours after coronary stenting (CD11b, p < 0.001; CD62 L, p < 0.05), but these changes showed less significance 48 hours after balloon angioplasty alone (CD11b, p < 0.05; CD62 L, p = NS). The gradients 48 hours after the procedures for both CD62P (r = 0.39, p < 0.05) and CD11b (r = 0.44, p < 0.01) were independently correlated with the late loss in the stent group, whereas the correlation was seen only for CD11b (r = 0.38, p < 0.05) in the balloon angioplasty group. Both platelet and neutrophil activation was greater after coronary stenting than after balloon angioplasty. Cellular interactions between platelets and neutrophils may be related to the progression of neointimal proliferation leading to restenosis after coronary stent implantation.

Angina Pectoris↗
PubMed2000

Monoamine oxidase inhibitors reduce conditioned fear stress-induced freezing behavior in rats.

The present study examined the acute anxiolytic effects of monoamine oxidase inhibitors on freezing behavior, a putative index of anxiety induced by conditioned fear stress. The selective serotonin 1A receptor agonist tandospirone (0.1-10 mg/kg) inhibited freezing dose dependently. The irreversible, non-selective monoamine oxidase inhibitors tranylcypromine (3 and 15 mg/kg) and phenelzine (30 and 80 mg/kg) reduced freezing significantly. Clorgyline (10 mg/kg, irreversible selective monoamine oxidase A inhibitor), N-(2-aminoethyl)-5-(m-fluorophenyl)-4-thiazole carboxamide (Ro 41-1049) (30 mg/kg, reversible selective monoamine oxidase A inhibitor), selegiline (3 mg/kg, irreversible selective monoamine oxidase B inhibitor) and lazabemide (10 mg/kg, reversible selective monoamine oxidase B inhibitor) had no effect on freezing behavior. However, combined administration of clorgyline (10 mg/kg) and selegiline (3 mg/kg) reduced freezing significantly, as well as combined administration of clorgyline (10 mg/kg) and lazabemide (10 mg/kg), Ro 41-1049 (30 mg/kg) and selegiline (3 mg/kg), or Ro 41-1049 (30 mg/kg) and lazabemide (10 mg/kg). These effects of monoamine oxidase inhibitors on freezing were not due to non-specific motor effects. These results suggest that acute inhibition of both monoamine oxidase A and B reduced anxiety or fear, while inhibition of monoamine oxidase A or B alone failed to reduce anxiety or fear.

Animals↗
PubMed2000

Galphas family G proteins activate IP(3)-Ca(2+) signaling via gbetagamma and transduce ventralizing signals in Xenopus.

During early embryonic development, IP(3)-Ca(2+) signaling transduces ventral signaling at the time of dorsoventral axis formation. To identify molecules functioning upstream in this signal pathway, we examined effects of a panel of inhibitory antibodies against Galphaq/11, Galphas/olf, or Galphai/o/t/z. While all these antibodies showed direct inhibition of their targets, their effects on redirection of the ventral mesoderm to a dorsal fate varied. Anti-Galphas/olf antibody showed strong induction of dorsal fate, anti-Galphai/o/t/z antibody did so weakly, and anti-Galphaq/11 antibody was without effect. Injection of betaARK, a Gbetagamma inhibitor, mimicked the dorsalizing effect of anti-Galphas/olf antibody, whereas injection of adenylyl cyclase inhibitors at a concentration which inhibited Galphas-coupled cAMP increase did not do so. The activation of Galphas-coupled receptor gave rise to Ca(2+) transients. All these results suggest that activation of the Galphas-coupled receptor relays dorsoventral signal to Gbetagamma, which then stimulates PLCbeta and then the IP(3)-Ca(2+) system. This signaling pathway may play a crucial role in transducing ventral signals.

Amino Acid Sequence↗
PubMed2000

High-dose-rate interstitial brachytherapy as a monotherapy for localized prostate cancer: treatment description and preliminary results of a phase I/II clinical trial.

PURPOSE: To improve results for localized prostate cancer, a prospective clinical trial of hyperfractionated Iridium-192 high-dose-rate (HDR) brachytherapy as a monotherapy was initiated. METHODS AND MATERIALS: Between May 1995 and September 1998, 22 implants were performed on 22 patients with localized prostate cancer (T1:T2:T3:T4 = 4:6:9:3) at Osaka University Hospital. Nineteen patients, who had T3-T4 tumors or pretreatment PSA >/= 20.0 ng/mL, received hormone therapy. No patient had external beam radiation. Transperineal needle implants using real-time ultrasound guidance were performed, followed by dose optimization program. Patients were irradiated twice a day, with a time interval of more than 6 h. Total dose was 48 Gy/8 fractions/5 days or 54 Gy/9 fractions/5 days. Acute toxicity was scored using the Radiation Therapy Oncology Group (RTOG) radiation morbidity scoring criteria. Median follow-up time was 31 months. RESULTS: HDR brachytherapy as a monotherapy was well-tolerated. No significant intra- or peri-operative complications occurred. No patient experienced acute toxicity of grade 3 or more. PSA levels normalized in 95% of patients within 20 months after irradiation. Four-year clinical and biochemical relapse-free rates were 95% and 55%, respectively. CONCLUSION: Acute toxicity with this method was acceptable. Further patient accrual and longer follow-up will allow comparison to other techniques.

Aged↗
PubMed2000

Lesser reduction in bone mineral density by the immunosuppressant, FK506, compared with cyclosporine in rats.

BACKGROUND: Posttransplantation osteopenia leading to osteoporosis induced commonly by treatment with immunosuppressants including cyclosporine (CsA) is a severe complication and results in lowering the quality of life in patients receiving organ transplantation. FK506 is a newly developed immunosuppressant and is currently being used for the prevention of rejection after organ transplantation. In this study, to investigate whether FK506 as well as CsA would cause osteopenia or not, we evaluated the effect of FK506 on bone mineral density and several parameters relevant to bone metabolism in comparison with that of CsA using normal rats. METHODS: Ten-week-old male Sprague-Dawley rats were treated with FK506 (vehicle, 1 mg/kg, and 3.2 mg/kg) or CsA (vehicle, 10 mg/kg, and 32 mg/kg) by daily oral gavage for 28 days. Bone mineral density of the femur, plasma insulin-like growth factor I (IGF-I), and urinary deoxypyridinoline were determined by peripheral quantitative computerized tomography, radioimmunoassay, and enzyme-linked immunosorbent assay, respectively. RESULTS: The reduction in bone mineral density of the femur was observed in both FK506- and CsA-treated rats. The reduction in CsA-treated rats, however, was statistically significant and strikingly severe, whereas that in FK506-treated rats was much less severe than CsA. Plasma IGF-I levels were significantly elevated in FK506-treated rats but not in CsAtreated rats. Urinary deoxypyridinoline levels were unchanged in FK506-treated rats but elevated in CsA-treated rats. CONCLUSIONS: Compared with CsA, FK506 does not appear to induce severe osteopenia by high-turnover bone metabolism in the rat by mediating via IGF-I induction in part. The results suggest that FK506 may exert favorable effects on bone metabolism in patients with organ transplantation compared with CsA. To assess this idea, further clinical investigations focused on bone metabolism will be required.

Amino Acids↗
PubMed2000

Platelet-activating factor (PAF)-dependent transacetylase and its relationship with PAF acetylhydrolases.

Platelet-activating factor (PAF)-dependent transacetylase (TA) is an enzyme that transfers an acetyl group from PAF to acceptor lipids such as lysophospholipids and sphingosine. This enzyme is distributed in membrane and cytosol of the cells. We previously revealed that TA purified from rat kidney membrane showed an amino acid sequence similarity to that of bovine PAF-acetylhydrolase (AH) (II). In the present study, we purified TA from the rat kidney cytosol and analyzed its amino acid sequence. The amino acid sequence of the cytosolic TA is similar to that of bovine PAF-AH (II) and membrane TA. To clarify the relationship between TA and PAF-AH (II), we isolated cDNA of rat PAF-AH (II). The predicted amino acid sequence of rat PAF-AH (II) from isolated cDNA included all the sequences found in TAs purified from the membrane and cytosolic TAs. In addition, monoclonal antibody to recombinant PAF-AH (II) cross-reacted with both cytosolic and membrane TAs. Consistent with sequence identity, recombinant PAF-AH (II) showed TA activity, whereas recombinant PAF-AH Ib, which is a different subtype of intracellular PAF-AHs, did not possess TA activity. Analysis of a series of site-directed mutant PAF-AH (II) proteins showed that TA activity was decreased, whereas PAF-AH activity was not affected in C120S and G2A mutant proteins. Thus, Cys(120) and Gly(2) are implicated in the catalysis of TA reaction in this enzyme. Furthermore, the transfer of acetate from PAF to endogenous acceptor lipids was significantly increased in a time-dependent manner in CHO-K1 cells transfected with PAF-AH (II) gene. These results demonstrate that PAF-AH (II) can function, as a TA in intact cells, and PAF-AH (II) and TA are the same enzyme.

1-Alkyl-2-acetylglycerophosphocholine Esterase↗
PubMed2000

Structure-function relationships of two closely related group IC3 intron ribozymes from Azoarcus and Synechococcus pre-tRNA.

The two group IC3 pre-tRNA introns from Azoarcus and Synechococcus share very analogous secondary structures. They are small group I ribozymes that possess only two peripheral domains, P2 and P9. However, the 3'-splice site hydrolysis activity of the Synechococcus ribozyme critically depends on P2 whereas that of Azoarcus does not, indicating that the structure-function relationships of the two ribozymes are strikingly different despite their structural resemblance. To identify the element(s) that determines the catalytic properties of these ribozymes, we undertook analyses of chimeric ribozymes prepared by swapping their structural elements. We found that the difference can be attributed to a small number of nucleotides within the conserved core region. Further analysis by employing in vitro selection revealed that a base triple interaction (P4bp3 x J6/7-2) is a critical element for determining activity and suggests the existence of a novel base quintuple involving the base triple P4bp5 x J8/7-5.

Azoarcus↗
PubMed2000

Neocortical origin and tangential migration of guidepost neurons in the lateral olfactory tract.

The early-generated neurons designated as lot cells specifically mark the future site of the lateral olfactory tract (LOT) and guide LOT axons. We investigated the mechanism of how lot cells develop and get localized in the LOT position. Lot cells differentiated from neuroepithelial cells in all regions of the neocortex but not from those in the ganglionic eminence in culture. Cell tracing analyses demonstrated that lot cells generated from the neocortex subsequently followed a tangential migration stream ventrally toward the LOT position. Mutant mouse embryos lacking the function of transcription factor Gli3 showed disturbances of the migration stream and translocation of lot cells in the dorsal telencephalon. These results reveal a new type of neuronal migration in the telencephalon and introduce an unexpected dramatic feature of the earliest regionalization of the telencephalon.

Animals↗
PubMed2000

Asymmetric construction of quaternary carbon centers by regio- and enantiocontrolled allylzincation

An allylic zinc reagent bearing a chiral bisoxazoline ligand adds to a substituted cyclopropenone acetal to produce an optically active cyclopropanone acetal possessing a quaternary chiral center in high yield with 97.8-99.8% ee. The steric effects of the bulky bisoxazoline ligand overwhelm the regioselectivity inherent to the electronic property of the olefinic acceptor. High pressure exerts favorable effects on the reaction rate without affecting the high enantio- or regioselectivity.

Journal Article↗
PubMed2000

A small structural element, Pc-J5/5a, plays dual roles in a group IC1 intron RNA.

The P4-P6 domain of group IC1 intron ribozymes such as that of the Tetrahymena autonomously folds into a hairpin-shaped structure in which the J5/5a region serves as a hinge. Phylogenetic comparisons of these IC1 introns suggested that the J5/5a region (termed Pc-J5/5a motif) in a subclass of IC1 introns such as the one from Pneumocystis carinii functions not only as a hinge but also as a receptor for a GAAA-tetraloop. We investigated the role of this motif by transplanting the structural unit, Pc-J5/5a motif, of Pneumocystis carinii into the P4-P6 domain of the Tetrahymena intron. The results showed that the Pc-J5/5a motif binds to a GAAA loop with high affinity and also facilitates the bending of the Tetrahymena P4-P6 domain more positively than the original J5/5a region.

Animals↗
PubMed2000

Determination of minute amounts of D-leucine in various brain regions of rat and mouse using column-switching high-performance liquid chromatography.

A highly sensitive method for the determination of minute amounts of D-Leu in biological samples was developed. For accurate and sensitive determination, a column-switching system using a micro ODS column and a chiral column was adopted. After pre-column derivatization of D- and L-Leu with NBD-F, the derivatives of the enantiomers were purified on a micro ODS column as a DL mixture. The eluted DL-Leu was then introduced to the chiral column, and each enantiomer was determined. The calibration curve for D-Leu, which was constructed by adding known amounts of D-Leu to a rat hippocampus, was linear from 1 to 1000 fmol (r>0.999), and the detection limit of added D-Leu was 1 fmol (S/N=5). Within-day and day-to-day precisions of D-Leu determination using the same homogenate of rat hippocampus were 5.11 and 5.25% (RSD), respectively. The content of D-Leu in rat hippocampus was 0.69 nmol/g wet tissue (the percentage of D-enantiomer for total Leu was 0.97%), which was consistent with the reported value. The distribution of D-Leu in mouse brain was also investigated, and the presence of D-Leu in various regions of the mammalian brain was first observed.

Animals↗