PubMed Health⌕ Search

Biomedical subjects

T Fukuda

Publications and source records attributed to T Fukuda.

At least 37 records · Page 2Linked to original sources
PubMed2005

[Acute left ventricular rupture and cardiac tamponade caused by blunt trauma; report of a case].

It is difficult to save patients with acute left ventricular rupture and cardiac tamponade caused by blunt trauma. A 67-year-old man hospitalized due to sustained multiple blunt trauma. The systolic blood pressure was 40 mmHg. Chest computed tomography (CT) and ultrasonic echocardiography revealed cardiac tamponade. Abdominal CT indicated left renal contusion. Pericardial drainage via the subxiphoid approach drew about 1,000 ml of blood from the pericardial sac, which only transiently increased blood pressure. Median sternotomy and subsequent pericardiotomy revealed pulsatile bleeding jet through a laceration of about 2.0 cm long in the left ventricle near the first diagonal branch. After complete digital compression, the portion was covered by a biological tissue adhesive/sealant sheet (TachoComb), which completely suppressed bleeding. The postoperative course was uneventful. He was discharged from the hospital on the 20th day after the operation.

Acute Disease↗
PubMed2005

Elution and adsorptive concentration of Japanese cedar (Cryptomeria japonica) pollen allergen in environmental water.

Elution of Japanese cedar pollen allergens (Cry j I and others) from pollen grains and its adsorptive concentration onto hydrophobic and hydrophilic surfaces were investigated using the surface plasmon resonance technique. Results showed that the allergen elution was obviously enhanced when the ion concentration was higher than that within the human body, indicating that the pollen tend to release its allergen in environmental water having a high ion concentration. However, higher adsorption capacity was observed on hydrophobic surface than hydrophilic surface. These results indicate that water puddles on roadsides beside heavy traffic including large amounts of ion compounds and hydrophobic diesel exhaust particles (DEPs) are a pollen allergen-DEP complex generator. DEPs are easily absorbed into the living body; therefore these mechanisms may be responsible for causing the highest incidence of pollinosis among residents living alongside roads with heavy automobile traffic.

Adsorption↗
PubMed2004

Formation of advanced tokamak plasmas without the use of an ohmic-heating solenoid.

A new operational scenario of advanced tokamak formation was demonstrated in the JT-60U tokamak. This was accomplished by electron cyclotron and lower hybrid waves, neutral beam injection, and the loop voltage supplied by the vertical field and shaping coils. The Ohmic heating (OH) solenoid was not used but a small inboard coil (part of the shaping coil), providing less than 20% of total poloidal flux, was used. The plasma thus obtained had both internal and edge transport barriers, with an energy confinement time of 1.6 times H-mode scaling, a poloidal beta of 3.6, and a normalized beta of 1.6, and a large bootstrap current fraction (>90%). This result opens up a possibility to reduce, and eventually eliminate, the OH solenoid from a tokamak reactor, which will greatly improve its economic competitiveness.

Journal Article↗
PubMed2004

Electrophysiology and immunohistochemistry in the hippocampal ca1 and the dentate gyrus of rats chronically exposed to 1-bromopropane, a substitute for specific chlorofluorocarbons.

1-Bromopropane is a newly introduced substitute for specific chlorofluorocarbons whose production was prohibited because of depletion of ozone layers. In this study, we analyzed disinhibitory effects induced by repetitive inhalation of 1-bromopropane for 12 weeks in the hippocampal CA1 and the dentate gyrus. In addition, reversal of the disinhibitory effects was examined 4 weeks after 1-bromopropane inhalation ceased. Exposure rats were placed in a stainless steel inhalation chamber at a concentration of 700 ppm, while the control group was provided only room air in the same type of chamber. Paired-pulse inhibition of population spike was considerably decreased (P<0.05) at 5 ms interpulse intervals in the CA1, and at 10 and 20 ms (P<0.05) interpulse intervals in the dentate gyrus in slices obtained from exposed rats following 4-, 8- and 12-week inhalation periods. The paired-pulse inhibition was decreased at 5 ms interpulse intervals in the dentate gyrus after 12 weeks of inhalation. These changes were not associated with the paired-pulse ratio of field excitatory postsynaptic potentials, suggesting a reduction of recurrent inhibition. The disinhibition was counteracted with the N-methyl-d-aspartate receptor antagonist dl-2-amino-5-phosphonopentameric acid in the dentate gyrus, whereas it was unchanged in the CA1. Tiagabine, a selective inhibitor of GABA transporter GAT1, increased the paired-pulse inhibition in the dentate gyrus, and the increase was less in the exposed rats compared with control rats (P<0.0003). The changes in both areas recovered to control levels 4 weeks after cessation of inhalation. Our electrophysiological studies suggest differential and reversible disinhibitory effects in the dentate gyrus and the CA1. 1-Bromopropane-induced disinhibition was further analyzed by immunohistochemical methods. There were no apparent morphological defects in either excitatory or inhibitory neuronal components, supporting the reversibility of physiological changes. In conclusion, chronic inhalation of 1-bromopropane induces a disinhibition in the CA1 and dentate gyrus that is reversible following cessation of exposure.

Action Potentials↗
PubMed2004

CYP3A5 genotype did not impact on nifedipine disposition in healthy volunteers.

CYP3A5 expression is regulated by single-nucleotide polymorphisms (SNPs). The CYP3A5 genotype might contribute to a marked interindividual variation in CYP3A-mediated metabolism of drugs. Nifedipine is a typical substrate of CYP3A4 and CYP3A5 in vitro. The aim of this study was to elucidate the influence of the CYP3A5 genotype on nifedipine disposition in healthy subjects. A single capsule containing 10 mg of nifedipine was administered to 16 healthy male Japanese subjects (eight subjects: CYP3A5(*)1/(*)3; eight subjects: CYP3A5(*)3/(*)3). Blood samples were collected to analyze the pharmacokinetics of serum nifedipine and nitropyridine metabolite (M-I). The area under the plasma concentration-time curve (AUC), the peak plasma concentration (C(max)) and the terminal half-life (t(1/2)) of nifedipine, and the ratio of the nifedipine AUC to M-I AUC showed large intragroup variations, but no significant differences between the two genotypes. Based on the present findings, the functional relevance of CYP3A5 polymorphism should be re-evaluated in clinical trials.

Adult↗
PubMed2004

Assessment of synthetic peptides of severe acute respiratory syndrome coronavirus recognized by long-lasting immunity.

In order to determine highly immunogenic severe acute respiratory syndrome coronavirus (SARS-CoV) epitope peptides capable of inducing long-lasting immunity, we first screened immunoglobulin-G (IgG) antibodies reactive to 197 different overlapping 15-mers from the SARS-CoV proteins in the sera of three infected patients. Forty-two peptides among them were reactive to the sera from all three patients. Consequently, we tested for the reactivity of these 42 peptides to patients' sera (n = 45) at 6-month post-infection. The significantly higher levels of IgG antibodies specific to three (S791, M207 and N161) of 42 peptides were detectable in the post-infection sera from 23 (51%), 27 (60%) and 19 (42%) of 45 patients, respectively. These three peptides, recognized by their long-lasting immunity, may provide a better understanding of the immunogenicity of SARS-CoV.

Enzyme-Linked Immunosorbent Assay↗
PubMed2004

Indomethacin, but not Helicobacter pylori, inhibits adaptive relaxation in isolated guinea-pig stomach.

Nonsteroidal anti-inflammatory drugs (NSAIDs) and Helicobacter pylori (H. pylori) are major factors in gastritis and peptic ulcer However, the role of NSAIDs and H. pylori infection in dyspepsia remains unclear. Gastric adaptive relaxation may be related to the pathogenesis of functional dyspepsia because the response is often disturbed in dyspeptic patients. In this study, we investigated the effects of indomethacin or H. pylori water extracts on gastric adaptive relaxation. This experiment was performed using the modified method of Desai et al. Isolated guinea-pig stomach in an organ bath was monitored for intragastric pressure and volume. Adaptive relaxation was induced by gastric luminal distention. The effects of indomethacin and H. pylori on gastric relaxation were tested in this system. Indomethacin (> 1 x 10(-5) M) significantly inhibited adaptive relaxation. Indomethacin (> 3 x 10(-6) M) induced gastric relaxation in a dose-dependent fashion. However, aspirin at a concentration sufficient for cyclooxygenase (COX)-1 inhibition did not induce gastric relaxation. Preincubation with N-nitro-L-arginine methyl ester, a nitric oxide (NO)-synthase inhibitor, inhibited indomethacin-induced gastric relaxation. Adaptive relaxation was not affected by H. pylori water extracts. In conclusion, indomethacin inhibited adaptive relaxation via prior gastric relaxation. NO production, but not COX-1 inhibition, may be involved in this effect of indomethacin. H. pylori water extracts may not have direct effects on adaptive relaxation. Inhibition of adaptive relaxation may be one of the major mechanisms underlying NSAID-induced dyspepsia.

Animals↗
PubMed2003

Hypermethylation of retrotransposons in the liverwort Marchantia paleacea var. diptera.

Three DNA fragments encoding part of a reverse transcriptase similar to that of Ty1- copia retrotransposons were isolated from suspension-cultured cells of the liverwort Marchantia paleacea var. diptera. Digestion of total DNA with methylation-sensitive and -insensitive isoschizomers revealed that, like those of the subtelomeric region, CpG sequences in retrotransposon genes were hypermethylated. The methylation status and expression of these retrotransposons was less affected by 5-azadeoxycytidine treatment compared to the subtelomeric region, which was considerably demethylated.

Amino Acid Sequence↗
PubMed2003

A neonatal form of glycogen storage disease type IV.

We report of an infant with neonatal glycogen storage disease type IV (GSD IV) who was examined for severe hypotonia and cardiomyopathy. On the muscle biopsy there were many fibers with diastase-resistant polyglucosan bodies. Glycogen branching enzyme (GBE1) activity in the muscle was markedly reduced. The infant had a homozygous single nucleotide deletion in the open reading frame of GBE1 gene.

1,4-alpha-Glucan Branching Enzyme↗
PubMed2003

Ultrastructural study of gap junctions between dendrites of parvalbumin-containing GABAergic neurons in various neocortical areas of the adult rat.

Parvalbumin (PV)-containing GABAergic neurons in the hippocampus form dual networks linked by both dendrodendritic gap junctions and mutual inhibitory synapses. Recent physiological studies have demonstrated similar functional connectivity among cortical GABAergic neurons, but the corresponding structures have not been fully analyzed at the electron microscopic level. In this study we examined detailed ultrastructural features of gap junctions between PV neurons in the mature neocortex. Light microscopic observations and confocal laser scanning microscopy revealed frequent dendrodendritic contacts between PV neurons. Electron microscopic analysis provided direct morphological evidence for the existence of gap junctions between 22 pairs of PV-immunoreactive dendrites in the visual, auditory, and somatosensory cortices. Their ultrastructural features that were characteristic of immunolabeled profiles were consistent with the general structure of gap junctions. In one case a gap junction coexisted with a dendrodendritic chemical synapse, making a mixed synapse. Importantly, we also encountered a gap junction between PV positive and negative, presumptive non-principal cell-derived, dendrites. Quantitative analysis was made in 16 pairs of PV positive dendrites forming gap junctions in the infragranular layers of the somatosensory cortex. Diameters of these dendrites ranged from 0.3 to 2.7 microm, suggesting diverse locations of gap junctions along the proximal-distal axis of dendritic trees, but the majority (81%) were less than 1 microm. The mean size of gap junctions along apposing membranes was 0.22+/-0.09 microm. By using this size, the theoretical value of a junctional conductance was estimated to be 2.1-5.3 nS. Dendrites of PV neurons in the infragranular layers of the somatosensory cortex were reconstructed light microscopically and the sites of contacts with other PV neurons were mapped. Although these contacts do not necessarily imply gap junctional coupling, their number (5.3+/-2.3 per cell, n=11) suggested the degree of connectivity of less than 10 coupling from single PV neurons with others. Sholl analysis revealed that only 38% of their dendrites occurred within 200 microm from the soma. The present study demonstrated detailed ultrastructural features of gap junctions between mature cortical PV neurons. These features will facilitate not only identification of gap junctions in variously labeled neurons but also analysis of their functional aspects by enabling theoretical estimate of their junctional conductances.

Animals↗
PubMed2002

Seronegative Lambert-Eaton myasthenic syndrome: study of 110 Japanese patients.

The authors characterized the clinical and immunologic features of 110 patients with Lambert-Eaton myasthenic syndrome (LEMS). Anti-P/Q-type voltage-gated calcium channels (VGCC) antibodies were detected in 85% of the patients (seropositive) but not in the rest (seronegative). Except for the indication that small cell lung carcinoma is less common in seronegative patients, no significant differences were found in the clinical characteristics of patients who had or did not have anti-P/Q-type VGCC antibodies. The results of passive transfer experiments suggest that seronegative LEMS is also an autoantibody-mediated disorder.

Adolescent↗
PubMed2002

Sigma-nucleus potential in A=28.

We have studied the (pi(-),K+) reaction on a silicon target to investigate the sigma-nucleus potential. The inclusive spectrum was measured at a beam momentum of 1.2 GeV/c with an energy resolution of 3.3 MeV (FWHM) by employing the superconducting kaon spectrometer system. The spectrum was compared with theoretical calculations within the framework of the distorted-wave impulse approximation, which demonstrates that a strongly repulsive sigma-nucleus potential with a nonzero size of the imaginary part reproduces the observed spectrum.

Journal Article↗
PubMed2002

Onset of complete atrioventricular block 15 years after ventricular septal defect surgery.

A 4-month-old girl with a ventricular septal defect underwent cardiac surgery. During the operation, complete atrioventricular block (CAVB) occurred, but on postoperative day 16 it converted to normal sinus rhythm with persistent complete right bundle branch block and left anterior hemiblock. Fourteen years after the operation, second-degree atrioventricular block was detected, but her general condition was good. Fifteen years after the operation, CAVB occurred. The intracardiac electrophysiologic recording revealed A-H and H-V block. A permanent pacemaker was implanted, and following the implantation she completely recovered.

Adolescent↗
PubMed2002

A new effective thermoluminescent material: LiCaAlF6:Ce.

Absorption, emission and thermostimulated luminescence (TSL) of as-grown and X ray irradiated pure and Ce-doped LiCaAlF6 crystals were investigated. Ce-containing samples demonstrate intensive TSL in the UV region (280-310 nm) with a main peak at 350 degrees C. It is found that the well known UV laser crystal LiCaAlF6:Ce is a promising thermoluminescent dosemetric material.

Aluminum Compounds↗