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T Togashi

Publications and source records attributed to T Togashi.

At least 19 recordsLinked to original sources
PubMed2006

Bulk- and surface-sensitive high-resolution photoemission study of two mott-hubbard systems: SrVO3 and CaVO3.

We study the electronic structure of Mott-Hubbard systems SrVO3 and CaVO3 with bulk and surface-sensitive high-resolution photoemission spectroscopy, using a vacuum ultraviolet laser, synchrotron radiation, and a discharge lamp (hv = 7-21 eV). A systematic suppression of the density of states (DOS) within approximately 0.2 eV of the Fermi level (EF) is found on decreasing photon energy, i.e., on increasing bulk sensitivity. The coherent band in SrVO3 and CaVO3 is shown to consist of surface and bulk-derived features, separated in energy. The stronger distortion on surface of CaVO3 compared to SrVO3 leads to a higher surface metallicity in the coherent DOS at EF, consistent with recent theory.

Journal Article↗
PubMed2006

Heavy-fermion-like state in a transition metal oxide LiV2O4 single crystal: indication of Kondo resonance in the photoemission spectrum.

We have performed a vacuum ultraviolet laser excited photoemission spectroscopy on a d-electron heavy-fermion-like material LiV2O4 single crystal. We observed a sharp peak structure in the density of states at approximately 4 meV above the Fermi level (E(F)). The evolution of the peak height corresponds well with the crossover behavior to the heavy-fermion-like state as observed in the thermal and transport properties. The position, shape, and temperature (T) dependence of the peak structure is quite similar to the Kondo resonance observed in conventional f-electron heavy Fermion compounds.

Journal Article↗
PubMed2005

Photoemission spectroscopic evidence of gap anisotropy in an f-electron superconductor.

We used low-temperature ultrahigh-resolution (360 microeV) photoemission spectroscopy with a laser as a photon source (Laser-PES) to study the superconducting (SC) gap of an f-electron superconductor CeRu2. The unique combination of the large escape depth expected from the known universal behavior and extremely high-energy resolution has enabled us to directly measure the bulk SC gap of an f-electron superconductor for the first time. The present study provides direct evidence for an anisotropic SC gap in CeRu2, and also demonstrates the potential of Laser-PES in investigating unconventional superconductivity realized in correlated d- and f-electron superconductors.

Journal Article↗
PubMed2003

NOx (nitrite/nitrate) in cerebral spinal fluids obtained from patients with influenza-associated encephalopathy.

It has become evident that the number of patients with a new type of influenza-associated encephalopathy is increasing in Japan. Nitric oxide (NO), a simple free radical gas, elicits a wide range of physiological and pathophysiological effects. We measured the nitrite/nitrate (NO x ) levels in cerebral spinal fluid obtained from patients with influenza-associated encephalopathy in order to evaluate the correlation between the NO production and the process of influenza-associated encephalopathy. Fifteen children were enrolled, aged from 1 to 9 years. As control we used 14 cerebral spinal fluids obtained from patients with urinary tract infection, respiratory infection or mumps meningitis without any sequela. NO 3 in influenza-associated encephalopathy was significantly higher than that of control group. On the other hand NO 2 was not significantly higher than that of control group. In particular, 4 out of 5 fatal cases revealed high NO 2 or NO 3. One case having normal levels in NO 2 and NO 3 showed that NH 3 was high. These results revealed that NO plays a role in influenza-associated encephalopathy through indirect effects of NO.

Brain↗
PubMed2001

Genetic loci controlling susceptibility to gamma-ray-induced thymic lymphoma.

BALB/c is a susceptible strain for the development of gamma-ray induced mouse thymic lymphoma whereas MSM shows resistance. Association analysis of 220 backcross mice between the two strains using 67 markers was carried out to identify loci involved in the control of susceptibility. The genotype of mice with lymphoma showed excess heterozygosity relative to MSM homozygosity at D2Mit15 and D4Mit12 and was skewed toward MSM-derived alleles at D5Mit5. The P values in Mantel-Cox test were 0.0048 (D2Mit15), 0.0034 (D4Mit12) and 0.0048 (D5Mit5), suggesting association at the three loci in the susceptibility. Cooperative effect on lymphomagenesis was also observed among the three loci. To obtain independent evidence for linkage at D4Mit12, we made partially congenic mice in which a D4Mit12 region in BALB/c was replaced by MSM-derived homolog. Examination for the lymphoma susceptibility in 78 progeny of the congenic mice confirmed the effect of the locus near D4Mit12 (P=0.0037). The result, together with the linkage analysis, shows that the locus near D4Mit12 is regarded as a confirmed linkage but the other two loci as marginally suggestive.

Alleles↗
PubMed2001

Molecular cloning and characterization of a gene expressed in mouse developing tongue, mDscr5 gene, a homolog of human DSCR5 (Down syndrome Critical Region gene 5).

For understanding the pathogenesis of Down syndrome (DS), it is important to identify and characterize the genes on Chromosome (Chr) 21, especially those in the Down syndrome critical region (DSCR) on Chr 21q22.2. Recently we have determined 33.5 Mb (more than 99%) of DNA sequence of Chr 21 and, from these sequence data, we identified a novel gene, DSCR5 (transcript = 0.8 kb), from DSCR by combination of computational gene prediction and cDNA screening. For functional analysis of DSCR5, we identified a mouse homolog of the DSCR5 cDNA, and termed it mDscr5 (transcript length = 0.8 kb). The gene was mapped to mouse Chr 16 C3-C4, the syntenic region of human Chr 21, and encodes an amino acid of 132 residues with 90% identity to DSCR5. In situ hybridization showed that mDscr5 is predominantly expressed in the developing tongue. To our best knowledge, no other gene in DSCR is reported to be expressed in tongue, so that DSCR5 may be the first candidate to elucidate the pathophysiology of tongue malformation observed in DS.

Amino Acid Sequence↗
PubMed2001

Elevated KL-6 levels in fatal measles pneumonia.

We measured KL-6 concentrations in serum samples from measles patients with various forms of pneumonia and abnormally elevated levels of KL-6 were found exclusively in four fatal cases of pulmonary insufficiency.

Adolescent↗
PubMed2000

A novel gene, DSCR5, from the distal Down syndrome critical region on chromosome 21q22.2.

Based on a detailed sequence of the distal Down syndrome critical region (DSCR), we predicted and molecularly cloned a novel gene, designated DSCR5. We determined the sequences of expressed sequence tags (ESTs) that almost matched the predicted cDNA sequence of DSCR5. Northern blot analysis showed that DSCR5 is expressed in several tissues including the liver, skeletal muscle, heart, pancreas and testis. To determine the 5'-end of DSCR5, the oligo-capping method was employed. Combining the EST sequence data and that from the oligo-capping experiments, we obtained the full-length cDNA sequence of DSCR5. DSCR5 had at least four types of alternatively spliced variants. According to the number of exons, they could be classified into two subtypes: DSCR5alpha and DSCR5beta. DSCR5alpha includes three splice variant subtypes, DSCR5alpha1, alpha2 and alpha3, which each has different first non-coding exon. In addition, the most abundantly isolated form, DSCR5alpha1, shows microheterogeneity of the mRNA start site. Comparison of the sequences between the predicted cDNA and the molecularly cloned cDNA revealed that the computer programs had limited validity to correctly predict the terminal exons. Thus, molecular cloning should always be required to complement the inadequacy of the computer predictions.

Alternative Splicing↗
PubMed2000

Epidemiology of influenza-associated encephalitis-encephalopathy in Hokkaido, the northernmost island of Japan.

BACKGROUND: It is well known that acute onset brain dysfunction, which usually is diagnosed as encephalitis or encephalopathy, occurs in association with influenza. However, this may have been underestimated as a rather infrequent event. Sixty-four infants and children developed encephalitis-encephalopathy during the five recent influenza seasons in Hokkaido, the northernmost island of Japan. METHODS: Inquiries were sent at the end of each season, from October 1994 to March 1999, to 94 hospitals and institutes in Hokkaido which accept pediatric age patients, asking if there were any admitted cases of encephalitis or encephalopathy. RESULTS: The patients were 42 boys and 22 girls and 47 (73.4%) were 4 years of age or younger. None of them had received an influenza vaccine nor had an oral administration of aspirin. Most of the patients became comatose with or without convulsions within a few days of the onset of fever. Twenty-eight (43.8%) patients died and 13 (20.3%) had neurological sequelae. Patients with clotting disorders, elevations of serum creatine kinase and/or aspartate aminotransferase and alanine aminotransferase, and brain CT abnormalities had a poor prognosis compared with patients without. Among these affected patients, the influenza genome (H3) was detected by polymerase chain reaction in nine cerebrospinal fluid samples, influenza virus A (H3N2) was isolated in 18 nasopharyngeal swab samples and a four-fold or greater rise in serum hemagglutinin inhibition antibody titer against H3N2 was observed in seven patients. CONCLUSIONS: It appears urgent to promote vaccination against influenza in young children to prevent these devastating disease conditions.

Brain Diseases↗
PubMed2000

Reconstitution of humoral immunity during pregnancy.

BACKGROUND: Recently, increasing attention has been paid to hormonal regulations of the immune system. MATERIALS AND METHODS: In this study, cord sera and the corresponding maternal sera were obtained at delivery. Sera from pregnant women were obtained at early, middle, and late stages of pregnancy. These sera were tested for titer and avidity of measles or mumps virus-specific immunoglobulin G (IgG) by means of a single-dilution, urea-denaturation enzyme-linked immunosorbent assay method. RESULTS: A positive and significant correlation was found between the titer and avidity of the virus-specific IgG, both in the cord sera and in the maternal sera. This correlation was established already at the early stage of pregnancy. There were no such correlations found in nonpregnant individuals. CONCLUSIONS: This is the first observation in human subjects that the avidity and concentration of the virus-specific IgG had a positive and significant correlation. Pregnancy must have some significant effects on the regulation of humoral immunity.

Adolescent↗
PubMed2000

Close association between pulmonary disease manifestation in Mycoplasma pneumoniae infection and enhanced local production of interleukin-18 in the lung, independent of gamma interferon.

To investigate pathophysiologies of Mycoplasma pneumoniae infection from an immunological point of view, we measured the levels of interleukin-18 (IL-18) (originally designated gamma interferon [IFN-gamma]-inducing factor) in 19 serum samples from 10 patients with pneumonia without pleural effusion (ages 1 to 16 years), 3 serum and 13 pleural fluid samples from 11 patients with pleural effusions (ages 11 months to 15 years), and 18 serum and 27 cerebrospinal fluid samples from 24 patients with central nervous system complications (ages 1 to 15 years). IL-18 was measured by a commercially available enzyme-linked immunosorbent assay kit (MBL, Nagoya, Japan). In addition, the levels of tumor necrosis factor alpha, IFN-gamma, IL-6, IL-12, and KL-6 (a mucin-like glycoprotein expressed on type 2 pneumocytes) were measured in selected samples. The results concerning pleural effusions showed that elevated levels of IL-18 in pleural fluid, but not in serum, were solely associated with a sustained fibrotic change of the lung on chest roentgenography which might represent a pathological feature of intraluminal organization. All the pleural fluid samples with elevated levels of IL-18 were positive by PCR for M. pneumoniae DNA. There was no association between IL-18 and IFN-gamma levels in serum or in the pleural fluid. On the other hand, elevated levels of IL-18 in serum, but not in cerebrospinal fluid samples, were observed in the cases complicated by central nervous system involvement, including profound brain dysfunction with seizures. Our study demonstrated that M. pneumoniae can induce IL-18 and that the enhanced local production of IL-18 in the lung is closely associated with pulmonary disease manifestation.

Adolescent↗
PubMed2000

Identification of canine alpha-lactalbumin.

The nucleotide sequence of canine alpha-lactalbumin cDNA from canine mammary tissue was determined by polymerase chain reaction with degenerate primers. A 742 base pairs nucleotide sequence cloned was similar to the size of mRNA in Northern blot analysis. The cDNA encodes 142 amino acid residues containing the conserved sequence motif of alpha-lactalbumin, demonstrating the highest homology with pig (73% identity-82% similarity) among the known amino acid sequences of alpha-lactalbumin. The canine cDNA also showed 71% identity-78% similarity with human, 58-73% with mouse, 60-74% with rat, 67-77% with goat, 66-77% with cattle, and 67-76% with sheep, respectively.

Amino Acid Sequence↗
PubMed2000

Molecular cloning and phylogenetic analysis of canine beta-casein.

A canine beta-casein cDNA was isolated from mammary tissue by polymerase chain reaction (PCR) using degenerate primers. It encodes 250 amino acids protein containing the conserved sequence motif of beta-casein. It showed the highest homology with snow-leopard (Uncia uncia (55-62% identity). It also showed 44-53% identity with human, 33-42%, identity with mouse, 29-37%, identity with rat, 43-53% identity with rabbit, 41-48% identity with pig, 44-51% identity with cattle and 44-50% identity with sheep. A 1.2-kb mRNA was detected in mammary tissue by Northern blot analysis. Phylogenetic analysis revealed that canine beta-casein formed a branch with lesser panda and snow leopard, which were grouped into carnivore.

Amino Acid Sequence↗
PubMed2000

[Influenza-associated encephalitis/encephalopathy in childhood].

Influenza-associated acute encephalitis/encephalopathy in childhood was reviewed. Annual incidence of this disease condition is estimated as 100-500 cases in Japanese children. Mortality rate of this disease would be as high as 40% died with a rapid fulminant course. Coagulopathies, hepatic dysfunctions and brain CT abnormalities were risk factors for the poor prognosis. The destruction of the vascular endothelial cells via the activation of inflammatory cytokines by influenzavirus would presumably be the pathomechanism of the neurological dysfunction.

Brain Diseases↗
PubMed1998

Childhood bacterial meningitis in Japan.

Haemophilus influenzae type b (Hib) vaccines currently are not used in Japan, but interest in preventing H. influenzae disease by immunization has grown. We performed a retrospective survey for bacterial meningitis in 6 prefectures of Japan. Questionnaires requested the age, sex, clinical outcome and identity of the etiologic organism, if known, of all patients with meningitis younger than 16 years of age who were admitted during calendar year 1994. Of 876 hospitals within the 6 study prefectures, 363 (41.4%) returned a completed questionnaire. There were 1769 cases of meningitis reported, of which 160 (9%) were considered bacterial in origin. H. influenzae was the most common cause of bacterial meningitis, accounting for 68 cases (43%). Sixty-six cases (97%) of H. influenzae meningitis occurred in children 4 years of age or younger, and 27 (40%) occurred in children <1 year of age. Calculated incidence rates based on the population of children 4 years of age or less for each prefecture ranged from 3.4 to 9.9 cases per 100000 (mean, 4.7 cases/100000). H. influenzae is the most common cause of meningitis in Japan, and the estimated incidence rates from this study are very similar to those previously reported from Japan. More comprehensive, prospective surveillance studies will be needed to define better the incidence of Hib meningitis and to aid in making rational decisions regarding the use of Hib vaccination in Japan.

Adolescent↗
PubMed1998

Analysis of mumps vaccine failure by means of avidity testing for mumps virus-specific immunoglobulin G.

To characterize patients with mumps vaccine failure, avidity testing was performed with the Enzygnost Anti-Parotitis Virus/IgG kit using a single-dilution-6 M urea denaturation method. Five groups of patients were tested. Group 1 consisted of 29 patients with primary mumps infections; group 2 was 20 children and adults with a definite history of natural infection; group 3 was 7 patients with a recent mumps vaccination, 1 of whom developed parotid gland swelling and aseptic meningitis; group 4 was 14 patients with mumps vaccine failure; and group 5 was 6 patients with recurrent episodes of parotitis in addition to a history of vaccination. On the basis of the results of groups 1 and 2, an avidity of </=31% was determined to be low, and >/=32% was determined to be high. Avidity maturation from low to high appears to occur around 180 days after the acute illness. The results of group 3 showed that the vaccine-induced immunoglobulin G (IgG) had very low avidity. Among the 14 patients in group 4, 12 patients, including 7 with a positive IgM response, were diagnosed as having secondary vaccine failures. The results of group 5 suggested the possibility that the avidity of the mumps vaccine-induced IgG remains low or borderline. These results showed that secondary mumps vaccine failure occurs not infrequently, even among school age children under condition in which the vaccine coverage is low (i.e., 33% in our study population), and therefore, vaccinees are prone to be exposed to wild-type viruses. Avidity testing should provide information useful for the analysis of mumps virus infections.

Adolescent↗
PubMed1998

Analysis of mycoplasmal pleural effusion by the polymerase chain reaction.

Ten pediatric patients with mycoplasmal pleuritis were tested for the presence of Mycoplasma pneumoniae in pleural fluid by the polymerase chain reaction (PCR). Three of the four PCR positive cases left a persistent consolidation. The remaining one was an infant who required mechanical ventilation. PCR may be useful in predicting delayed resolution of roentgenographic abnormality.

Adolescent↗