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Biomedical subjects

K Ueno

Publications and source records attributed to K Ueno.

At least 19 recordsLinked to original sources
PubMed2006

Correlations between bone mineral density and demographic, lifestyle, and biochemical variables in community-dwelling Japanese women 69 years of age and over.

INTRODUCTION: A few epidemiologic studies have comprehensively attempted to identify risk factors for low bone mineral density (BMD) in elderly Asian women. The purpose of this study was to identify demographic, lifestyle, and biochemical factors correlated with BMD in elderly Japanese women 69 years of age and over. METHODS: The study design was cross-sectional. The subjects were 583 ambulatory women aged 69 years and over, and their average age was 74.3 (SD 4.4) years. Predictor variables were age, reproductive history, anthropometric indices, grip strength, calcium intake, lifestyle information, and serum 25-hydroxyvitamin D, 1,25-dihydroxyvitamin D (1,25(OH)(2)D), osteocalcin (OC), and undercarboxylated osteocalcin (ucOC) values. The outcome variable was forearm BMD measured with a DTX-200 osteometer. RESULTS: Simple linear regression analyses showed that BMD was significantly positively associated with body height, weight, body mass index, grip strength, serum albumin concentration, and "housework," and negatively associated with age, years since menopause, age at menarche, number of children, serum 1,25(OH)(2)D concentration, serum OC concentration, and ucOC concentration. The stepwise multiple regression analysis showed that weight (beta=0.00316, SE=0.00028, R(2)=0.180), age (beta=-0.00321, SE=0.00050, R(2)=0.108), log-transformed serum OC (beta=-0.0445, SE=0.0064, R(2)=0.053), log-transformed serum 1,25(OH)(2)D (beta=-0.0401, SE=0.0074, R(2)=0.050), "farmwork" (beta=0.00904, SE=0.00426, R(2)=0.005), and serum 25(OH)D concentration (beta=0.000281, SE=0.000120, R(2)=0.003) were significantly associated with BMD. CONCLUSION: It was concluded that body weight is a major predictor of forearm BMD among the factors measured in this study in independent Japanese women 69 years of age and over and that serum 1,25(OH)(2)D concentration may be associated with cortical BMD. Maintenance of body weight is very important for maintaining BMD in this population, unless a large weight aggravates obesity-related diseases. A follow-up study is needed to confirm these findings.

25-Hydroxyvitamin D 2↗
PubMed2005

Renormalization-group and numerical analysis of a noisy Kuramoto-Sivashinsky equation in 1 + 1 dimensions.

The long-wavelength properties of a noisy Kuramoto-Sivashinsky (KS) equation in 1 + 1 dimensions are investigated by use of the dynamic renormalization group (RG) and direct numerical simulations. It is shown that the noisy KS equation is in the same universality class as the Kardar-Parisi-Zhang (KPZ) equation in the sense that they have scale invariant solutions with the same scaling exponents in the long-wavelength limit. The RG analysis reveals that the RG flow for the parameters of the noisy KS equation rapidly approach the KPZ fixed point with increasing strength of the noise. This is supplemented by numerical simulations of the KS equation with a stochastic noise, in which scaling behavior close to the KPZ scaling can be observed even in a moderate system size and time.

Journal Article↗
PubMed2005

Evidence for a novel racemization process of an asparaginyl residue in mouse lysozyme under physiological conditions.

We examined chemical reactions in mouse lysozyme after incubation under physiological conditions (pH 7 and 37 degrees C). After incubation for 8 weeks, racemization was observed specifically at Asn127 among the 19 Asp/Asn residues in mouse lysozyme. Furthermore, analysis of the primary structure showed that the racemized residue was not Asp, but Asn, which demonstrates that deamidation and isomerization did not occur. These results mean that this racemization occurs without forming a succinimide intermediate. This is the first example of D-asparaginyl formation in a protein occurring during the racemization process under physiological conditions.

Amino Acid Sequence↗
PubMed2005

Does incineration turn infectious waste aseptic?

Incineration of infectious waste is considered to be biologically safe. We performed basic experiments to confirm that bacillus spores are killed by incineration in a muffle furnace. Biological samples containing 10(6) spores of Bacillus stearothermophilus were placed in stainless steel Petri dishes and then into hot furnaces. The furnace temperature and duration of incineration were 300 degrees C for 15 min, 300 degrees C for 30 min, 500 degrees C for 15 min, 500 degrees C for 30 min and 1100 degrees C for 3 min. We confirmed that all spores of B. stearothermophilus were killed at each of these settings. The effect of incineration seems to be equivalent to that of sterilization, based on the satisfactory sterilization assurance level of 10(-6).

Geobacillus stearothermophilus↗
PubMed2005

Genetic polymorphisms and haplotypes of the human cardiac sodium channel alpha subunit gene (SCN5A) in Japanese and their association with arrhythmia.

Genetic variations in cardiac ion channels have been implicated not only as the causes of inherited arrhythmic syndromes, but also as genetic risk factors for some acquired arrhythmias. To elucidate the potential roles of genetic polymorphisms of the alpha subunit of the voltage-gated sodium channel type V (SCN5A) in cardiac rhythm disturbance, the entire SCN5A coding exons and their flanking introns were sequenced in 166 Japanese arrhythmic patients and 232 healthy controls. We detected 69 genetic variations, including 54 novel ones. Out of the 12 novel nonsynonymous single nucleotide polymorphisms (SNPs), p.Leu1988Arg was found at a frequency of 0.015. The other 11 SNPs were rare (0.001), with 6 found in arrhythmic patients and 5 in healthy controls. The frequency of a novel intronic SNP, c.703+130G>A, was significantly higher in the patients than in the controls, suggesting this SNP is associated with an unknown risk factor for arrhythmia. Following linkage disequilibrium analysis, the haplotype structure of SCN5A was inferred using high-frequency SNPs. The frequency of the haplotype harbouring both p.Leu1988Arg and the common SNP p.His558Arg (haplotype GG) was significantly lower in the patients than in the controls. This finding suggests that this haplotype (GG) might have been positively selected in the controls because of its protective effect against arrhythmias. This study provides fundamental information necessary to elucidate the effect of genetic variations in SCN5A on channel function and cardiac rhythm in Japanese, and probably in the Asian population.

Arrhythmias, Cardiac↗
PubMed2004

Pattern formation in crystal growth under parabolic shear flow. II.

Wavy pattern of ice with a specific wavelength occurs during ice growth from a thin layer of undercooled water flowing down the surface of icicles or inclined plane. In a previous paper [Phys. Rev. E 68, 021603 (2003)]], we have found that restoring forces due to gravity and surface tension is a factor for stabilization of morphological instability of the solid-liquid interface. However, the mechanism for the morphological instability and stability of the solid-liquid interface has not been well understood. In the present paper, it is shown that a phase difference between fluctuation of the solid-liquid interface and distribution of heat flux at the deformed solid-liquid interface, which depends on the magnitude of the restoring forces, is a cause of the instability and stability of the interface. This mechanism is completely different from the usual Mullins-Sekerka instability due to diffusion and stabilization due to the Gibbs-Thomson effect.

Journal Article↗
PubMed2004

Purification and characterization of an endopeptidase that has an important role in the carboxyl terminal processing of antihypertensive peptides in Lactobacillus helveticus CM4.

AIMS: To purify and characterize a peptidase that can catalyse C-terminal processing of antihypertensive peptide from Lactobacillus helveticus CM4. METHODS AND RESULTS: An endopeptidase which seems to process the carboxyl terminal end of two antihypertensive peptides, Val-Pro-Pro and Ile-Pro-Pro, was purified from Lactobacillus helveticus CM4 by four stages of column chromatography, using synthetic pro-peptide as a substrate. The molecular weight of the purified enzyme was estimated to be 67,000 by SEPHACRYL S-200 and 70,000 by SDS-PAGE analysis. The purified enzyme generated: (i) Val-Pro-Pro from Val-Pro-Pro-Phe-Leu and Val-Pro-Pro-Phe-Leu-Gln-Pro, and (ii) Ile-Pro-Pro from Ile-Pro-Pro-Leu-Thr and Ile-Pro-Pro-Leu-Thr-Gln-Thr, but theses peptides could not be generated from Val-Pro-Pro-Phe, Val-Pro-Pro-Phe-Leu-Gln, Ile-Pro-Pro-Leu and Ile-Pro-Pro-Leu-Thr-Gln. Part of the amino terminal sequence of the purified enzyme had homology to a previously reported pepO gene product. CONCLUSION: These results suggest that the purified endopeptidase isolated in this study have an important role in the carboxyl terminal processing of two antihypertensive peptides in Lact. helveticus CM4.

Antihypertensive Agents↗
PubMed2003

Pattern formation in crystal growth under parabolic shear flow.

Morphological instability of the solid-liquid interface occurring in a crystal growing from an undercooled thin liquid bounded on one side by a free surface and flowing down inclined plane, is investigated by a linear stability analysis under shear flow. It is found that restoring forces due to gravity and surface tension is an important factor for stabilization of the solid-liquid interface on long length scales. This is a stabilizing effect different from the Gibbs-Thomson effect. A particular long wavelength mode of about 1 cm of wavy pattern, observed on the surface of icicles covered with a thin layer of flowing water is obtained from the dispersion relation, including the effect of flow and restoring forces.

Journal Article↗
PubMed2003

Development of dento-maxillofacial cone beam X-ray computed tomography system.

We have developed a cone beam X-ray computed tomography (CT) system to make more accurate three-dimensional (3-D) images for diagnosis of dento-maxillofacial region. The developed system has sufficient spatial resolution, resolution of 3-D images and image distortion for diagnosis of dentomaxillofacial region.

Humans↗
PubMed2002

Comparison of emptying between gastric and colonic conduits following esophagectomy.

The emptying of gastric and colonic conduits following esophagectomy was evaluated. Ten consecutive patients who underwent esophagectomy for malignant diseases were divided into two groups as follows: Group I which consisted of 5 patients who underwent pyloroplasty and in whom the gastric greater curvature was used for reconstruction; and Group II which consisted of 5 patients in whom the colonic conduit was used because of previous gastrectomy. The conduits were placed in the retrosternal spaces in all the patients. The radiopaque markers swallowing test and digestive tract scintigraphy were performed to evaluate emptying two months after surgery. The radiopaque markers swallowing test demonstrated that marker rings quickly disappeared from the gastric conduits but remained in the colonic conduits for as long as three hours. Digestive tract scintigraphy demonstrated that there was no significant difference in the 60-minute clearance rate of 99mTc-DTPA from the conduits between the two groups. The results suggested that tiny food fragments remained in the haustral pockets of the colonic conduits, which may be a disadvantage of these conduits.

Aged↗
PubMed2001

Involvement of interleukin-1beta/nitric oxide pathway in the postischemic impairment of long-term potentiation of the rat hippocampus.

To investigate whether postischemic cerebral dysfunction occurs via the interleukin-1 beta/nitric oxide (IL-1beta/NO) pathway, we examined the effects of an IL-1beta antagonist on long-term potentiation (LTP) impairment and excessive NO production in the rat hippocampus after 10-min global ischemia. Intracerebroventricilar administration of the IL-1beta antagonist attenuated NO production and rescued LTP impairment in the perforant path-dentate gyrus synapses, observed 1 day and 4 days after ischemic insult, respectively. There was an inverse relationship between LTP in the dentate gyrus synapses and hippocampal NO production. Centrally applied IL-1beta mimicked the consequences of transient ischemia in LTP formation and hippocampal NO production in non-ischemic rats. These findings indicate that the IL-1beta/NO pathway is involved in the hippocampal LTP impairment observed in the postischemic brain.

Animals↗
PubMed2001

Trehalose sensitivity in Drosophila correlates with mutations in and expression of the gustatory receptor gene Gr5a.

Drosophila taste gene Tre is located on the distal X chromosome and controls gustatory sensitivity to a subset of sugars [1, 2]. Two adjacent, seven-transmembrane domain genes near the Tre locus are candidate genes for Tre. One (CG3171) encodes a rhodopsin family G protein receptor [3, 4], and the other (Gr5a) is a member of a chemosensory gene family encoding a putative gustatory receptor [5-7]. We carried out molecular analyses of mutations in Tre to elucidate their involvement in the gustatory phenotype. Here, we show that Tre mutations induced by P element-mediated genomic deletions disrupt Gr5a gene organization and the expression of Gr5a mRNA, while disruption of the CG3171 gene or its expression was not always associated with mutations in Tre. In flies with the spontaneous mutation Tre(01), both CG3171 and Gr5a mRNAs are transcribed. Coding sequences of these two candidate genes were compared among various strains. A total of three polymorphic sites leading to amino acid changes in CG3171 were not correlated with the gustatory phenotype. Among four nonsynonymous sites in Gr5a, a single nucleotide polymorphism leading to an Ala218Thr substitution in the predicted second intracellular loop cosegregated with Tre(01). Taken together, the mutation analyses support that Gr5a is allelic to Tre.

Animals↗
PubMed2001

Mechanistic study of enantiomeric recognition of primary amino compounds using an achiral crown ether with cyclodextrin by capillary electrophoresis and nuclear magnetic resonance.

A model and theoretical equations are presented to investigate the enantiomeric recognition mechanism of primary amino compounds using an achiral crown ether with cyclodextrin by capillary electrophoresis (CE) and nuclear magnetic resonance (NMR). Association constants were calculated from CE and 1H NMR experiment results on the basis of the model and the equations. The key step of chiral recognition was identified from those values. Using CE analyses of three primary amino compounds [1-(1-naphthyl)ethylamine; 1-aminoindan; 1,2,3,4-tetrahydro-1-naphthylamine], the key step was identified with the equilibrium where the complex of a primary amino compound and 18-crown-6 becomes associated with 2,6-di-O-methyl-beta-cyclodextrin for all the three compounds. From the 1H NMR analyses of 1-(1-naphthyl)ethylamine, the key step was identified with the equilibrium where the complex of 1-(1-naphthyl)ethylamine and 18-crown-6 becomes associated with beta-cyclodextrin.

Acrylic Resins↗
PubMed2001

Enantiomeric separations of primary amino compounds by capillary electrochromatography with monolithic chiral stationary phases of chiral crown ether-bonded negatively charged polyacrylamide gels.

A novel enantiomeric separation method by capillary electrochromatography with chiral crown ether-bonded negatively charged polyacrylamide gels is presented. Two kinds of chiral crown ether derivatives, (+)-tetraallyl 18-crown-6 carboxylate and (+)-18-crown-6 tetracarboxylic acid 2-allyl ester were synthesized and allowed to covalently bind to a negatively charged polyacrylamide gel, a so-called monolithic stationary phase, respectively. The gel was placed in fused-silica tubing, the walls of which had been activated with a bifunctional reagent to make the resulting gel bind covalently to the inner surface. Enantiomeric separations of 12 primary amino compounds were achieved using these columns and mobile phases of 200 mM triethanolamine-300 mM boric acid buffers with high efficiencies of up to 135000 plates m(-1). Both the within- and between-run reproducibilities of retention time and separation factor were good. The reproducibilities of retention time and separation factor for three different columns prepared from a different batch of monomers were acceptable. The gel-filled capillaries were stable for at least 13 months with intermittent use for 3 months followed by storage at room temperature for 10 months. The result of the optical purity test of alanine-2-naphthylamide is also described.

Amines↗
PubMed2001

Differential expression of Gh1 and Gh 2 genes by competitive RT-PCR in rainbow trout pituitary.

The expressions of the GH1 and GH2 genes were examined by competitive RT-PCR and whole-mount in situ hybridization of pituitary of starved rainbow trout (Oncorhynchus mykiss). lambda RNA having GH primers at both 5' and 3' sites of the gene was used for the competitive RT-PCR, and thermostable reverse transcriptase produced a reasonable band when authentic RNA was examined. The amount of GH1 gene expression was significantly (P < 0.05) greater than that of GH2. Although almost the same amount of GH1 gene expression was obtained during the day, it was significantly (P < 0.05) decreased at midnight. However, there was no significant change in GH2 gene expression in the daily cycle. There were also some differences in gene expression in the pituitary: GH2 gene was more widely expressed than GH1. However, the signal intensity of the GH1 gene was greater than that of GH2.

Animals↗