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H Miyazaki

Publications and source records attributed to H Miyazaki.

At least 19 recordsLinked to original sources
PubMed2006

The PDZ domain protein PDZK1 interacts with human peptide transporter PEPT2 and enhances its transport activity.

The proton-coupled peptide transporter PEPT2 (SLC15A2) mediates the high-affinity low-capacity transport of small peptides as well as various oral peptide-like drugs in the kidney. In contrast to its well-characterized transport properties, there is less information available on its regulatory mechanism, although the interaction of PEPT2 to the PDZ (PSD-95, DglA, and ZO-1)-domain protein PDZK1 has been preliminarily reported. To examine whether PDZK1 is a physiological partner of PEPT2 in kidneys, we started from a yeast two-hybrid screen of a human kidney cDNA library with the C-terminus of PEPT2 (PEPT2 C-terminus (PEPT2-CT)) as bait. We could identify PDZK1 as one of the positive clones. This interaction requires the PDZ motif of PEPT2-CT detected by a yeast two-hybrid assay, in vitro binding assay and co-immunoprecipitation. The binding affinities of second and third PDZ domains of PDZK1 to PEPT2-CT were measured by surface plasmon resonance. Co-immunoprecipitation using human kidney membrane fraction and localization of PEPT2 in renal apical proximal tubules revealed the physiological meaning of this interaction in kidneys. Furthermore, we clarified the mechanism of enhanced glycylsarcosine (Gly-Sar) transport activity in PEPT2-expressing HEK293 cells after the PDZK1 coexpression. This augmentation was accompanied by a significant increase in the V(max) of Gly-Sar transport via PEPT2 and it was also associated with the increased surface expression level of PEPT2. These results indicate that the PEPT2-PDZK1 interaction thus plays a physiologically important role in both oligopeptide handling as well as peptide-like drug transport in the human kidney.

Biological Transport↗
PubMed2006

A preliminary study on the relationship between stimulated saliva and periodontal conditions in community-dwelling elderly people.

OBJECTIVES: The purpose of this study was to explore the relationship between flow rate and spinnbarkeit of stimulated whole saliva and periodontal conditions in healthy elderly people. METHODS: Three hundred and fifty-five dentate subjects aged 76 years were included. The pocket probing depth (PD), attachment level (AL), and bleeding on probing (BOP) were measured. Stimulated whole saliva was collected and the salivary flow rate (SFR) was calculated. Then, salivary spinnbarkeit (SS) was immediately measured. RESULTS: The mean SFR and SS were 1.44 ml/min and 1.91 mm, respectively. SFR was not significantly related to each periodontal parameter. On the other hand, subjects with SS 2.00 mm exhibited a significantly higher mean PD (p<0.05), % of sites with PD>or=4mm (p<0.05), mean AL (p<0.01), % of site with AL>or=4mm (p<0.05) and % of sites with AL>or=6mm (p<0.01) than subjects in the other three groups (one-way ANOVA). In the logistic regression analysis, the factors significantly associated with the highest quintile of PD>or=4mm were: the low salivary flow and the high salivary spinnbarkeit (OR 3.84), current smokers (OR 5.08), cleaning interdental spaces rarely/never (OR 2.12), and frequent BOP (OR 5.20). CONCLUSION: These findings suggest that high salivary spinnbarkeit in addition to a low salivary flow rate might be a high risk for periodontal disease in elderly people.

Activities of Daily Living↗
PubMed2006

Two types of autoantibody-mediated thrombocytopenia in patients with systemic lupus erythematosus.

OBJECTIVES: To determine whether autoantibodies to two platelet-specific antigens, glycoprotein IIb/IIIa (GPIIb/IIIa) and thrombopoietin receptor (TPOR), contribute to thrombocytopenia in patients with systemic lupus erythematosus (SLE). METHODS: Circulating B cells producing anti-GPIIb/IIIa antibodies and serum anti-TPOR antibodies were measured in 32 SLE patients with thrombocytopenia, 30 SLE patients without thrombocytopenia, 92 patients with idiopathic thrombocytopenia and 60 healthy controls. The megakaryocyte density in bone-marrow smears from all the patients with thrombocytopenia was evaluated. RESULTS: Anti-GPIIb/IIIa and anti-TPOR antibody responses were more frequent in SLE patients with thrombocytopenia than in those without thrombocytopenia (88 vs 17%, P<0.0001; and 22% vs 0%, P=0.01, respectively). The frequencies of these platelet-related antibodies were comparable between SLE patients with thrombocytopenia and patients with idiopathic thrombocytopenia. Twenty-nine (91%) SLE patients with thrombocytopenia had either anti-GPIIb/IIIa or anti-TPOR antibody, and six had both. In SLE patients with thrombocytopenia, the anti-TPOR-positive patients had significantly higher frequencies of megakaryocytic hypoplasia and poorer therapeutic responses to corticosteroids and intravenous immunoglobulin than did the anti-TPOR-negative patients, most of whom had the anti-GPIIb/IIIa antibody alone. CONCLUSIONS: Anti-GPIIb/IIIa and anti-TPOR antibodies are major factors contributing to SLE-associated thrombocytopenia, but the clinical presentations associated with these autoantibodies are different.

Adult↗
PubMed2006

Preliminary study on the effect of oral care on recovery from surgery in elderly patients.

This study aimed to clarify the effectiveness of post-operative oral care, including tooth brushing, denture cleaning and tongue cleaning, after digestive tract surgery. Subjects included 30 elderly patients aged 60-98 years (74.9 +/- 7.8 years) who underwent digestive tract surgery. Subjects were randomly divided into an intervention group and a control group. In the intervention group, the following oral care was provided daily over a 5-min period in the morning starting at baseline (day of surgery) and continued for 5 days: gargling with povidone iodine, tooth brushing, denture cleaning using a special brush and tongue cleaning using a tongue brush. In the control group, the subjects only gargled with povidone iodine. We compared the following variables between the two groups at baseline and 5 days later: the sensation of dry mouth, intra-oral gas concentration, pulmonary sounds, body temperature and bacterial flora. The number of patients with abnormal pulmonary sounds (dry or moist rales) increased from 1 to 2 in the intervention group and from 0 to 4 in the control group (P < 0.05). The average number of bacterial species per subject for the control group was 3.64 +/- 1.34 pre-operatively and 3.50 +/- 1.74 post-operatively, whereas that for the intervention group was 3.08 +/- 0.95 pre-operatively and 2.62 +/- 0.65 post-operatively. In the intervention group, there was a significant decrease in the number of bacterial species (P < 0.05). These findings indicate that post-operative oral care in elderly patients undergoing digestive tract surgery lowers the number of bacterial species found in the oral cavity. This effect, in turn, might improve respiratory function.

Aged↗
PubMed2006

Propofol formulated with long-/medium-chain triglycerides reduces the pain of injection by target controlled infusion.

BACKGROUND: Propofol is a widely used intravenous anesthetic although its injection pain is a common and unpleasant problem. Long-/medium-chain triglyceride (LCT/MCT) propofol has been introduced, as its low free propofol content is expected to reduce injection pain compared with LCT propofol. Target controlled infusion (TCI) differs from conventional induction in the initial infusion pattern. During induction using TCI, we investigated injection pain caused by two propofol solutions with different triglyceride compositions. METHODS: Fifty patients, ASA I-II, with adequate communicative ability, were randomly assigned to two groups. TCI was conducted with Diprifusor for LCT and with BeComSim (custom-made software) for LCT/MCT. The target blood concentration was set at 4 microg/ml for both groups. At 30, 60, and 120 s after the infusion, patients were asked questions regarding the severity of pain on a 0-10 pain score. The total dose of propofol and the time required to induce anesthesia were also investigated. RESULTS: The LCT/MCT propofol group had a larger number of pain-free patients and showed lower severity of pain than the LCT group [the number of pain-free patients being 11 and 3, respectively (P < 0.05), and median maximum pain being 0 and 4.5, respectively (P < 0.01)]. The dose and time required for induction were not significantly different between the groups (dose of 84 +/- 27 and 80 +/- 24 mg, respectively, and time of 119 +/- 60 and 107 +/- 55 s, respectively). CONCLUSION: Our study showed that the frequency and severity of pain during TCI induction with propofol could be significantly reduced using LCT/MCT propofol rather than LCT propofol.

Adult↗
PubMed2006

Fluoride intake from food and liquid in Japanese children living in two areas with different fluoride concentrations in the water supply.

The purpose of this study was to estimate the average daily amount of fluoride from the diet ingested by Japanese children of ages susceptible to dental fluorosis in two areas with different fluoride concentrations in the water supply. Thirty-eight children aged 2-8 years participated in a survey of fluoride intake. Twenty-one out of 38 children lived in an area in which the community water fluoride concentration was an average of 0.555 ppm (moderate fluoride area: MFA), and 17 lived in a low fluoride area (LFA), which ranged between 0.040 and 0.131 ppm. To measure the fluoride intake, diets were collected with a duplicate-diet technique. The fluoride concentrations in each sample were measured using the diffusion technique of Taves and the electrode technique. Meanwhile, after clinical examinations for dental caries and fluorosis, 228 subjects aged 13-15 years were selected for analysis from the same communities. The mean DMFT in the MFA was significantly lower than that in the LFA. The severest grade of dental fluorosis observed was 'very mild' according to Dean's fluorosis index in both areas. The total daily fluoride intakes were 0.0252-0.0254 mg F/kg/day in the MFA and 0.0126-0.0144 mg F/kg/day in the LFA. Differences in the fluoride concentration of drinking water in this study were reflected in the fluoride intake from the diet in a typical Japanese diet.

Adolescent↗
PubMed2005

Unilateral agenesis and hypoplasia of the internal carotid artery: a report of three cases.

We report one patient with agenesis and two with hypoplasia of the internal carotid artery (ICA) from an angiographic series of 1275 consecutive patients. In all three patients, MRI and MR angiography were used to establish the anatomical situation; however, they may not clearly distinguish between hypoplasia and agenesis or acquired stenosis or occlusion of the ICA. In such cases, CT of the skull base may be obtained to clarify matters. In all patients, retrograde flow via a large posterior communicating artery was demonstrated. Single-photon emission computed tomography confirmed both the adequacy of cerebral perfusion and the preservation of vasomotor reactivity.

Aged↗
PubMed2005

High-transmission waveguide with a small radius of curvature at a bend fabricated by use of a circular photonic crystal.

A bent photonic crystal waveguide was fabricated by use of a lattice pattern of a circular photonic crystal that allowed high transmission for a broad band of wavelengths with a small radius of curvature at a bend. The waveguide was fabricated by use of alumina rods with a diameter of 3 mm. Windows of high transmission as a result of waveguiding were observed near 9 and 15 GHz. By measurement of the relative wave intensity [E]2 along the line defects, the propagation losses in the straight and the bent sections were estimated at 9.3 GHz to be 0.04 and 0.03 dB/mm, respectively.

Journal Article↗
PubMed2005

New concept of spare receptors and effectors.

The present study provides a new concept of the spare receptor. Model [A]: 1) Several receptors connect with an effector; 2) if an agonist occupies one of the receptors connecting with one effector, the effector fully functions. When the number of receptors connecting with one effector is "m", the relationship between the functional effectors (E) and the concentration of agonists ([a]) is as follows: [formula: see text] where Rt is the total number of receptors and Kd is the agonist dissociation constant from the receptor. Model [B]: 1) Several receptors connect with an effector; 2) only when agonists occupy all of the receptors connecting with one effector, the effector functions. The relationship between E and [a] is as follows: [formula: see text] If m=1, equations (I) and (II) are exactly the same as the Michaelis-Menten equation. If m is larger than 1, the apparent saturation in the effector efficiency becomes larger in Model [A], and smaller in Model [B], respectively. The dissociation of the fractional efficiency of effectors from the fractional binding of agonists to receptors becomes larger as m becomes larger in both models. Further, we propose a variable model, including the concept of agonist-occupancy-dependent stability in the functional conformation change of the effector; only when more than j pieces of receptors connecting with one effector are occupied by agonists, the effector functions (Model [M]). The relationship between E and [a] is as follows: [formula: see text]

Mathematics↗
PubMed2005

Long-period accelerometer monitoring shows the role of physical activity in overweight and obesity.

CONTEXT: Physical activity (PA) plays an important role in obesity. A new accelerometer has been developed to assess total energy expenditure as well as PA. OBJECTIVE: To investigate the association of PA with overweight and obesity in Japanese men and women, a large cross-sectional study was performed using a single-axis accelerometer. DESIGN, SETTING AND PARTICIPANTS: Population-based cross-sectional study of Japanese 18-84 y of age. Height, body weight and PA were measured in 400 male and 388 female Japanese volunteers from 1999 to 2000. The outcome measurements were overweight and obesity, which are defined as a body mass index >/=25 kg/m(2). PA was measured for 1 to 4 weeks and was then categorized into three activity levels, which were defined as light, moderate and vigorous PA. RESULTS: Prevalence of overweight and obesity was 22.3%. Number of steps and time spent in moderate and vigorous PA per day were lower in overweight and obese individuals. No difference was found in time spent in light PA. Individuals who are in the 4th and 5th quintile of moderate and vigorous PA showed a significantly lower body mass index. When odd ratios (ORs) of overweight and obesity estimated by logistic regression were used as effect measures, overweight and obesity were negatively associated with vigorous PA (ORs=0.91). CONCLUSION: These results indicate that overweight and obese individuals have a lower step rate and are spending less time for moderate to vigorous PA. Participation in vigorous PA is an important predictor of overweight and obesity.

Adolescent↗
PubMed2005

The relationship between bone mineral density and the number of remaining teeth in community-dwelling older adults.

Tooth loss and osteoporosis may share common aetiologic agents which influence the process of both diseases. The purpose of this study was to evaluate the relationship between bone mineral density (BMD) of the os calcis and the number of remaining teeth, controlling the known confounding factors. Among all 70-year-old inhabitants in Niigata City, Japan, 600 people were selected randomly in order to have approximately the same number of each gender. We analysed 460 subjects. We evaluated the BMD of the os calcis using an ultrasound bone densitometer, then we counted the number of remaining teeth excluding the third molars. Stiffness is a clinical index which is calculated by the spread speed of supersonic waves. To monitor the general health condition of the subjects, serum levels of disease markers and smoking habits were also investigated. The mean number of remaining teeth for the osteopenia group (OG) and the no-osteopenia group (NOG) was 15.97+/- 9.98 and 18.31+/- 8.06, respectively in females, and 16.32+/- 9.93 and 18.12+/- 9.33, respectively in males (OG versus NOG, P=0.047 by two-way anova). In addition, stiffness was significantly associated with the number of remaining teeth (CV=-0.157, P=0.005) using linear multiple regression analysis adjusted by four other variables. In this study, there was a significant relationship between the number of remaining teeth and BMD of the os calcis.

Adipose Tissue↗
PubMed2005

Decreased prothrombotic effects of pegylated recombinant human megakaryocyte growth and development factor in thrombocytopenic state in a rat thrombosis model.

Previous in vitro studies demonstrated that thrombopoietin (TPO) acts on platelets to activate a variety of intracellular signaling pathways and to enhance platelet sensitivity to multiple agonists. Little is known, however, about whether TPO exerts prothrombotic effects in vivo. The aim of this study was to examine the effects of pegylated recombinant human megakaryocyte growth and development factor (PEG-rHuMGDF), a pegylated N-terminal domain of human TPO, in a rat model of venous thrombosis. A microthrombus was photochemically induced on the vessel wall of a mesenteric venule, but the vessel was not occluded by it. A single intravenous injection of PEG-rHuMGDF (3 microg kg(-1)) after the thrombus generation into normal rats enhanced the thrombus size, resulting in transient thrombotic occlusion in the majority of rats. Stimulatory effects on thrombus growth were also observed following administration of glycosylated recombinant human full-length TPO (6 microg kg(-1)). In rats rendered thrombocytopenic by total body irradiation, however, PEG-rHuMGDF, even at 300 microg kg(-1), did not induce a significant increase in thrombus size or thrombotic occlusion. Platelets from thrombocytopenic rats had decreased surface levels of c-Mpl and decreased sensitivity to PEG-rHuMGDF in an in vitro aggregation response. Thus, decreased prothrombotic effects of PEG-rHuMGDF in thrombocytopenic rats might be the result not only of low platelet counts but also of decreased platelet reactivity to PEG-rHuMGDF. These results indicate that PEG-rHuMGDF has little effect on venous thrombus formation in thrombocytopenic states associated with high endogenous TPO levels.

Animals↗
PubMed2005

Serum vitamin C-periodontal relationship in community-dwelling elderly Japanese.

OBJECTIVE: To determine the relationship between serum vitamin C and periodontitis as estimated by clinical attachment loss (CAL) in community-dwelling elderly Japanese. MATERIAL AND METHODS: This analysis was confined to 413 Niigata citizens aged 70 years in whom the data for serum vitamin C and CAL were available. High-pressure liquid chromatography method was used to ascertain the serum vitamin C levels while CAL was assessed on six sites of all teeth present including third molars by means of pressure-sensitive probes. Other variables included gender, smoking, toothbrushing frequency, number of teeth present and random blood sugar levels. RESULTS: Serum vitamin C concentration was inversely related to CAL (r=-0.23, p<0.00005) at bivariate level. Multiple linear regression analysis showed that CAL was 4% greater in subjects with lower serum vitamin C levels than in subjects with higher serum vitamin C levels notwithstanding smoking, diabetes, oral hygiene, gender or number of teeth present. CONCLUSION: The findings suggested that serum vitamin C might have relatively weak but a statistically significant relationship with periodontitis in this elderly population.

Aged↗
PubMed2005

Relationship between bleeding on probing and periodontal disease progression in community-dwelling older adults.

OBJECTIVE: The main objective of this study was to determine the relationship between bleeding on probing (BOP) and periodontal disease progression in community-dwelling older adults. METHODS: A 3-year longitudinal study was carried out in 229 non-smoking healthy older adults aged 70 years. Using pressure-controlled periodontal probes, BOP, pocket depth and attachment level at 13,289 sites were measured annually. Periodontal disease progression was defined as an increase in attachment loss of >or=3 mm from the baseline to the final examination. The backward stepwise logistic regression analysis was performed to assess the relationship between the total number of sites with BOP in the four examinations and periodontal progression. RESULTS: Logistic regression analysis showed that the odds ratios of BOP frequency for periodontal disease progression ranged from 1.4 to 6.2 after controlling for pocket depth >or=4 mm at baseline, number of missing teeth, jaw type and tooth site. CONCLUSION: Increasing frequencies of bleeding might increase the probability of periodontal disease progression in community-dwelling older adults.

Aged↗
PubMed2004

Isotropic photonic gaps in a circular photonic crystal.

We investigated the optical properties of a circular photonic crystal (CPC) for which the distance between lattices was systematically distributed. The transmission spectra of CPC composed of alumina cylinders were examined in the frequency region from 0 to 20 GHz. We show that photonic gaps are obtained not only in CPCs but also in phase-shifted CPCs. The isotropic photonic gaps are evidenced by changes in the incident angle of a millimeter wave.

Journal Article↗
PubMed2004

Observation of millimeter-wave radiation generated by the interaction between an electron beam and a photonic crystal.

We observed directional light emission in the millimeter-wave region when a high-energy (150 MeV) electron beam passes just above a photonic crystal made of polytetrafluoroethylene beads ( approximately 3.2 mm in diameter). The relation between the momentum and the energy of the emitted photons strongly suggests that the observed light is generated by the umklapp scattering process that changes the evanescent waves emitted by the electron beam into observable ones. By comparing the observed spectra with calculated ones based on the photonic band structure, we found that generated photons excite the photonic band modes making them observable as enhanced fine structures in the emission spectra.

Journal Article↗
PubMed2004

Relationship between dental care and oral health in institutionalized elderly people in Japan.

This study examined the relationship between dental care and dental health status in institutionalized elderly people in Japan through a 6-year prospective cohort study. All the 719 subjects received both baseline and follow-up surveys. The uptake of dental care was examined at the follow-up survey. We examined the relationship between baseline variables and the provision of dental care, and the relationship between dental care and change of oral health status. About 47% of the subjects and about 60% of the baseline dentate subjects received some dental treatment during the 6-year follow-up period. The subjects who were in better systemic and dental health at baseline used dental services frequently. The number of teeth needing extraction decreased in the subjects who received dental treatment, and increased in the untreated subjects. Denture status was better in the treated subjects than in the untreated subjects. Dental care appears to be an important factor in maintaining a healthy oral status for the institutionalized elderly.

Aged↗