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K Kato

Publications and source records attributed to K Kato.

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

Magnetic-field switching of crystal structure in an orbital-spin-coupled system: MnV2O4.

We studied the magnetic and structural properties of spinel MnV2O4, which has S=5/2 spin with no orbital degrees of freedom on the Mn2+ site and S=1 spin and three orbital degrees of freedom on the V3+ site. We found that the ferrimagnetic ordering at TN=56.5K and the structural phase transition at Ts=53.5K are closely correlated in this compound and found a switching of crystal structure between cubic and tetragonal phases by the magnetic field. This phenomenon can be explained by the coupling between orbital and spin degrees of freedom in the t2g states of the V site.

Journal Article↗
PubMed2005

Human proinsulin C-peptide prevents proliferation of rat aortic smooth muscle cells cultured in high-glucose conditions.

AIMS/HYPOTHESIS: Proinsulin C-peptide is involved in several biological activities. However, the role of C-peptide in vascular smooth muscle cells is unclear. We therefore investigated its effects, in vascular smooth muscle cells in high-glucose conditions. METHODS: Rat aortic smooth muscle cells were cultured with 5.5 or 20 mmol/l glucose with or without C-peptide (1 to 100 nmol/l) for 3 weeks. Proliferation activities, the protein expression of platelet-derived growth factor (PDGF)-beta receptor, the phosphorylation of p42/p44 mitogen-activated protein (MAP) kinases, and glucose uptake were measured. RESULTS: The proliferation activities increased approximately three-fold under high-glucose conditions (p<0.05). C-peptide suppressed hyperproliferation activities that were induced by high glucose. This happened in a dose-dependent manner from 1 to 100 nmol/l of C-peptide. C-peptide (10 and 100 nmol/l) inhibited the increased protein expression of PDGF-beta receptor and the phosphorylation of p42/p44 MAP kinases that had been induced by high glucose (p<0.05). Furthermore, 100 nmol/l of C-peptide augmented the impaired glucose uptake in the high-glucose conditions. CONCLUSIONS/INTERPRETATION: These observations suggest that C-peptide could prevent diabetic macroangiopathy by inhibiting smooth muscle cell growth and ameliorating glucose utilisation in smooth muscle cells. C-peptide may thus be a novel agent for treating diabetic macroangiopathy in patients with type 1 and type 2 diabetes.

Animals↗
PubMed2005

Nucleotide sequence of melon yellow spot virus M RNA segment and characterization of non-viral sequences in subgenomic RNA.

The nucleotide sequence of melon yellow spot virus (MYSV) M RNA segment was determined. The M RNA segment contains one open reading frame (ORF) encoding 308 amino acids (aa) in the sense orientation and another ORF encoding 1,127 aa in the complementary orientation, which were homologous to the NSm protein and G1/G2 glycoprotein precursor (Gp) protein, respectively. Amino acid sequences identities with the other tospovirus suggested that MYSV is closely related to groundnut bud necrosis virus and watermelon silver mottle virus. To analyze subgenomic RNA of the M RNA segment, RNA transcripts corresponding to the NSm and Gp genes were specifically amplified, and the nucleotide sequence of the 5' terminal region was determined. Sequence analysis of the NSm and Gp transcripts showed that they had a non-viral sequence 12-18 and 10-18 nucleotides long, respectively. Although these sequences varied considerably, in more than half of the cases, a cytosine residue was observed at the 3' end of the non-viral leader sequence, which suggests that the viral transcriptase prefers certain cap-donor sequences harboring a 3'CA dinucleotide.

Base Sequence↗
PubMed2005

Genetic variation and geographic distribution of porcine reproductive and respiratory syndrome virus in Japan.

Porcine reproductive and respiratory syndrome virus (PRRSV) has two genotypes, the North American-type (NA-type) and the European-type (EU-type), and each genotype is also genetically diverged. We sequenced the ORF5 gene of 30 PRRSVs isolated from 23 prefectures of Japan during 1992 and 1993 and during 2000 and 2001. All of the isolates were of the NA-type. Phylogenetic analysis of the overall NA-type viruses isolated from around the world identified five major genetic clusters. The 1992-1993 Japanese samples belonged to only two genetic clusters, while the 2000-2001 samples included more diverged ORF5 genomes. One genetic cluster, which included 63% (20/32) of Japanese isolates, one Taiwanese isolate and one Chinese isolate, was mainly found in the eastern part of Japan. Another genetic cluster, which was found in various areas around the world, was distributed in the western part of Japan.

Animals↗
PubMed2005

Mapping QTLs for grain dormancy on wheat chromosome 3A and the group 4 chromosomes, and their combined effect.

A major QTL for grain dormancy, QPhs.ocs-3A.1, derived from the highly dormant wheat Zenkoujikomugi (Zen), has been identified in a study made under a controlled environment. Further investigations were needed to dissect the precise position and expression of QPhs.ocs-3A.1 under different field conditions because the ability to detect genetic loci for grain dormancy traits is compromised by environmental effects and genotype/environment interactions. Group 4 chromosomes have also been shown to be possible sites of QTLs for grain dormancy. The objectives of this study were (1) to locate additional molecular markers in the QPhs.ocs-3A.1 region, (2) to identify QTLs on the group 4 chromosomes and (3) to elucidate their combined effects. We examined the recombinant inbred lines (RILs) from a cross between Chinese Spring (CS) and Zen over a 3-year period in one location and 1 year in a different location. In an interval mapping study QPhs.ocs-3A.1 was mapped to within the 4.6 cM region flanked by Xbarc310 and Xbcd907 at the proximal end of the short arm of chromosome 3A. QPhs.ocs-3A.1 was confirmed to be the predominant dormancy QTL since it explained a large portion (11.6-44.8%) of the phenotypic variation, and was strongly displayed under dormancy-breaking conditions or at low germination temperatures. For QPhs.ocs-4A.1, identified on the long arm of chromosome 4A, and QPhs.ocs-4B.1, on the centromeric region of the long arm of Chr 4B, the LOD peak positions and the desirable allele were consistent between the trials, while the LOD scores and contribution to the phenotypic variation varied. Transgressive segregants were observed among the 125 RILs and most of them had a combination of the three alleles conferring a higher dormancy: the Zen alleles at QPhs.ocs-3A.1 and QPhs.ocs-4A.1 and the CS allele at QPhs.ocs-4B1. This demonstrated a combined effect of the desirable alleles on accelerating grain dormancy, with their total effect being superior to that of Zen.

Chromosome Mapping↗
PubMed2005

Intraoral minor salivary gland tumors: a clinicopathological study of 82 cases.

We present a retrospective study of 82 patients with intraoral minor salivary gland tumors which were diagnosed from 1979 to 2003 in Gifu University Hospital. The histological diagnoses were reevaluated according to the 1991 WHO classification. A total of 82 tumors, consisting of 55 benign and 27 malignant tumors, were found in 28 male and 54 female Japanese patients; the male-to-female ratio was 1:1.9. The mean age of the patients was 51.4+/-18.1 years. The tumors affected the palate (n = 64), the buccal region (n = 10), the upper lip (n = 6), the floor of the mouth (n = 1), and the retromolar region (n = 1). Histologically, the tumors were classified as pleomorphic adenoma (n = 54), papillary cystadenoma (n = 1), adenoid cystic carcinoma (n = 10), mucoepidermoid carcinoma (n = 8), acinic cell carcinoma (n = 3), adenocarcinoma (n = 2), basal cell adenocarcinoma (n = 1), papillary cystadenocarcinoma (n = 1), and carcinoma in pleomorphic adenoma (n = 2). From the results of the present study and review of the literature, it is suggested that the minor salivary gland tumors in Japan may be characterized by a higher incidence of benign tumors, especially of pleomorphic adenoma; a more marked tendency for female predominance; a higher incidence of palatal involvement; and a rarer occurrence of polymorphous low grade adenocarcinoma, in comparison with those reported in the literature from outside of Japan.

Adenocarcinoma↗
PubMed2005

FLT3 mutations in normal karyotype acute myeloid leukemia in first complete remission treated with autologous peripheral blood stem cell transplantation.

We retrospectively analysed the significance of FLT3 mutations in patients with acute myeloid leukemia (AML) having a normal karyotype, who were treated with high-dose chemotherapy and autologous peripheral blood stem cell transplantation (auto-PBSCT). In all, 34 patients with normal karyotype AML in first complete remission receiving high-dose chemotherapy and auto-PBSCT were analysed based on the presence or absence of FLT3/ITDs and FLT3/D835. They were 16 males and 18 females and with a median age of 41.5 years. FLT3/ITDs were detected in eight of 34 patients (23.5 %), and FLT3 D835 mutations in two of 34 patients (5.9%). White blood cell count (P=0.0087), serum concentration of lactate dehydrogenase (P=0.005), and percentages of peripheral blood (P=0.0131) and bone marrow (BM) blasts (P=0.0312) were significantly higher in patients showing the FLT3 mutations. Overall survival (OS) and disease-free survival (DFS) were similar between patients with or without FLT3 mutations (5 year DFS, 67.5 vs 68.55%, P=0.819; 5 year OS, 64.81 vs 78.88%, P=0.4457, by the log-rank test). FLT3 mutations demonstrate no further prognostic impact in patients with normal karyotype AML in first CR treated with high-dose chemotherapy and auto-PBSCT. Myeloablative chemotherapy supported by auto-PBSCT may overcome any poor prognostic implications of FLT3 mutations.

Acute Disease↗
PubMed2005

Demonstration of reversed flow in segmental branches of the portal vein with hand-held color Doppler ultrasonography after hematopoietic stem cell transplantation.

Hepatic veno-occlusive disease (VOD) is a severe complication of hematopoietic stem cell transplantation (SCT). When monitored with hand-held color Doppler ultrasonography during day -7 to +35 around SCT, reversed blood flow in the segmental branches of the portal vein was detected in nine of 56 patients who had undergone SCT. Three of nine patients had clinical evidence of VOD, but six patients did not fulfill the criteria for diagnosis of VOD initially. Two patients progressed to clinical VOD at a later date and the reversed portal flow disappeared with or without treatment for VOD in the other four patients. Monitoring for reversed portal flow with color Doppler ultrasonography may be a useful tool for the early diagnosis of VOD, and may improve prognosis by allowing early initiation of treatment.

Adolescent↗
PubMed2005

Integrated nuclear data utilisation system for innovative reactors.

A five-year research and development project on an integrated nuclear data utilisation system was initiated in 2002, for developing innovative nuclear energy systems such as accelerator-driven systems. The integrated nuclear data utilisation system will be constructed as a modular code system, which consists of two sub-systems: the nuclear data search and plotting sub-system, and the nuclear data processing and utilisation sub-system. The system will be operated with a graphical user interface in order to enable easy utilisation through the Internet by both nuclear design engineers and nuclear data evaluators. This paper presents an overview of the integrated nuclear data utilisation system, describes the development of a prototype system to examine the operability of the user interface and discusses specifications of the two sub-systems.

Computer Graphics↗
PubMed2005

Changes in coagulation-fibrinolysis marker and neutrophil elastase following the use of tourniquet during total knee arthroplasty and the influence of neutrophil elastase on thromboembolism.

BACKGROUND: To clarify in detail the mechanism underlying the development and exacerbation of deep venous thrombosis (DVT) and/or pulmonary thromboembolism (PTE), we focused on the following factors: the thrombin-antithrombin III complex (TAT), D-dimer and neutrophil elastase (NE). We basically investigated whether NE played an important role in the development of PTE I a mice model. METHODS: Nineteen rheumatoid arthritis (RA) and six osteoarthritis (OA) patients underwent total knee arthroplasty (TKA) with tourniquet, and 13 RA and 12 OA patients underwent TKA without tourniquet in each group. The blood levels of TAT, D-dimer and NE were measured before surgery, immediately after and during the days following surgery. For the induction of experimental PTE due to coagulation of platelets, adenosine diphosphate (ADP) was administrated, and human NE with ADP was also administrated for the development of DVT and/or PTE. RESULTS: The rates of increase in the mean TAT, D-dimer and NE levels in the group with tourniquet were statistically higher than those in the group without tourniquet after surgery. The mortality of the mouse due to PTE increased from 43 to 67% following ADP and human NE administration compared to a single ADP administration. Histological changes of the lungs in the mice receiving NE and ADP injections were characterized by a diffuse and extensive accumulation of platelets and fibrin in alveolar capillaries and other microvessels. CONCLUSION: We suggest that during TKA, the use of tourniquet induces local release of a large amount of NE from neutrophils, inducing the development of DVT and/or PTE and their exacerbation.

Adenosine Diphosphate↗
PubMed2005

Injuries in elite motorcycle racing in Japan.

OBJECTIVES: To investigate the incidence and pattern of injuries, relative risks, and factors affecting incidence among elite motorcycle competitors in Japan. METHODS: A total of 117 elite motorcycle competitors including 36 road racers, 60 motocross racers, and 21 trial bike riders completed a questionnaire about injuries. RESULTS: Sixty major injuries (25 in road racing, 32 in motocross, and three in trial bike riding) were reported. The most common injuries were fractures (45), followed by ligament injuries (8), dislocations (5), and soft tissue injuries (2). The overall injury rate was 22.4 per 1000 hours, and the death rate was zero. There was no significant correlation between risk of injury and age, experience, or accumulated competition points. CONCLUSIONS: Injury rates in competitions such as road racing and motocross are high, and therefore additional safety measures are needed to protect competitors from injury.

Adult↗
PubMed2005

[Surgically resected lung cancer in patients complicated with diffuse interstitial pulmonary shadow].

In 25 patients operated on for idiopathic interstitial pneumonia (IIP) associated with primary lung cancer, we clinically examined the predictive factors related to the acute exacerbation of IIP preoperatively and during operation. Most were male heavy smokers. Ages ranged 57 to 78 years. Standard surgery was performed in 11 patients, extended resection in 4 patients and limited resection in 10 patients. The incidence of postoperative acute exacerbation of IIP was 40% (10 patients). These patients were treated with steroid pulse therapy, 3 patients died due to acute exacerbation but 7 patients recovered. It seemed difficult to anticipate postoperative exacerbation of IIP based on preoperative patients evaluation and the degree of surgical invasiveness. Seven patients were alleviated with erythromycin before and after the operation and 4 patients were alleviated with high-dose steroid during or after surgery, with these patients not developing exacerbation of IIP. From these results, it was suggested that high-dose steroid administration during or after surgery and erythromycin before and after the operation were effective to avoid postoperative exacerbation of IIP.

Aged↗
PubMed2004

GM2-gangliosidosis variant 0 (Sandhoff-like disease) in a family of Japanese domestic cats.

A five-month-old, female Japanese domestic shorthair cat with proportionate dwarfism developed neurological disorders, including ataxia, decreased postural responses and generalised body and head tremors, at between two and five months of age. Leucocytosis due to lymphocytosis with abnormal cytoplasmic vacuolations was observed. The concentration of G(M2)-ganglioside in its cerebrospinal fluid was markedly higher than in normal cats, and the activities of beta-hexosaminidases A and B in its leucocytes were markedly reduced. On the basis of these biochemical data, the cat was diagnosed antemortem with G(M2)-gangliosidosis variant 0 (Sandhoff-like disease). The neurological signs became more severe and the cat died at 10 months of age. Histopathologically, neurons throughout the central nervous system were distended, and an ultrastructural study revealed membranous cytoplasmic bodies in these distended neurons. The compound which accumulated in the brain was identified as G(M2)-ganglioside, confirming G(M2)-gangliosidosis. A family study revealed that there were probable heterozygous carriers in which the activities of leucocyte beta-hexosaminidases A and B were less than half the normal value. The Sandhoff-like disease observed in this family of Japanese domestic cats is the first occurrence reported in Japan.

Animals↗
PubMed2004

MCG measurement in the environment of active magnetic shield.

MCG (Magnetocardiography) measurement by a SQUID gradiometer was attempted with only active magnetic shielding (active shielding). A three-axis-canceling-coil active shielding system, where three 16-10-16 turns-coil sets were put in the orthogonal directions, produces a homogeneous magnetic field in a considerable volume surrounding the center. Fluxgate sensors were used as the reference sensors of the system. The system can reduce environmental magnetic noise at low frequencies of less than a few Hz, at 50 Hz and at 150 Hz. Reducing such disturbances stabilizes biomagnetic measurement conditions for SQUIDs in the absence of magnetically shielded rooms (MSR). After filtering and averaging the measured MCG data by a first-order SQUID gradiometer with only the active shielding during the daytime, the QRS complex and T wave was clearly presented.

Electricity↗
PubMed2004

Active magnetic compensation composed of shielding panels.

Magnetically shielded rooms (MSRs) with materials of high permeability and active shield systems have been used to shield magnetic noise for biomagnetic measurements up to now. However, these techniques have various disadvantages. Therefore, we have developed a new shielding system composed of shielding panels using an active compensation technique. In this study, we evaluated the shielding performance of several unit panels attached together. Numerical and experimental approaches indicated that the shielding factor of a cubic model composed of 24 panels was 17 for uniform fields, and 7 for disturbances due to car movement. Furthermore, the compensation space is larger than that of an ordinary active system using large coils rather than panels. Moreover, the new active compensation system has the important advantage that panels of any shape can be assembled for occasional use because the unit panels are small and light.

Electromagnetic Fields↗
PubMed2004

Randomized placebo-controlled trial assessing the effect of bifidobacteria-fermented milk on active ulcerative colitis.

BACKGROUND: Probiotics are efficacious for treating and maintaining remission of ulcerative colitis. AIM: To conduct a randomized placebo-controlled trial of bifidobacteria-fermented milk supplementation as a dietary adjunct in treating active ulcerative colitis. METHODS: Twenty patients with mild to moderate, active, ulcerative colitis randomly received 100 mL/day of bifidobacteria-fermented milk or placebo for 12 weeks with conventional treatment. RESULTS: Clinical and endoscopic activity indices and histological scores were similar in the two groups before treatment. Although improvements were significant in both groups, the clinical activity index was significantly lower in the bifidobacteria-fermented milk than in the placebo group after treatment. The post-treatment endoscopic activity index and histological score were significantly reduced in the bifidobacteria-fermented milk, but not the placebo group. Increases in faecal butyrate, propionate and short-chain fatty acid concentrations were significant in the bifidobacteria-fermented milk, but not the placebo group. No adverse effects were observed in either group. CONCLUSION: Supplementation with this bifidobacteria-fermented milk product is safe and more effective than conventional treatment alone, suggesting possible beneficial effects in managing active ulcerative colitis. This is a pilot study and further larger studies are required to confirm the result these preliminary results.

Adult↗